Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Acute Cholecystitis View online at http://pier.acponline.org/physicians/diseases/d642/d642.html Module Updated: CME Expiration: 2013-02-20 2016-02-20 Author Badri Man Shrestha, MS, MPhil, MD, FRCS Table of Contents 1. Prevention .........................................................................................................................2 2. Diagnosis ..........................................................................................................................4 3. Consultation ......................................................................................................................8 4. Hospitalization ...................................................................................................................11 5. Therapy ............................................................................................................................12 6. Patient Education ...............................................................................................................16 7. Follow-up ..........................................................................................................................17 References ............................................................................................................................19 Glossary................................................................................................................................23 Tables...................................................................................................................................25 Figures .................................................................................................................................30 Quality Ratings: The preponderance of data supporting guidance statements are derived from: level 1 studies, which meet all of the evidence criteria for that study type; level 2 studies, which meet at least one of the evidence criteria for that study type; or level 3 studies, which meet none of the evidence criteria for that study type or are derived from expert opinion, commentary, or consensus. Study types and criteria are defined at http://smartmedicine.acponline.org/criteria.html Disclaimer: The information included herein should never be used as a substitute for clinical judgement and does not represent an official position of the American College of Physicians. Because all PIER modules are updated regularly, printed web pages or PDFs may rapidly become obsolete. Therefore, PIER users should compare the module updated date on the offical web site with any printout to ensure that the information is the most current available. CME Statement: The American College of Physicians is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing education for physicians. The American College of Physicians designates this enduring material for a maximum of 1 AMA PRA Category 1 CreditTM. Physicians should claim only credit commensurate with the extent of their participation in the activity. Purpose: This activity has been developed for internists to facilitate the highest quality professional work in clinical applications, teaching, consultation, or research. Upon completion of the CME activity, participants should be able to demonstrate an increase in the skills and knowledge required to maintain competence, strengthen their habits of critical inquiry and balanced judgement, and to contribute to better patient care. Disclosures: Badri Man Shrestha, MS, MPhil, MD, FRCS, current author of this module, has no financial relationships with pharmaceutical companies, biomedical device manufacturers, or health-care related organizations. Deborah Korenstein, MD, FACP, Co-Editor, PIER, has no financial relationships with pharmaceutical companies, biomedical device manufacturers, or health-care related organizations. Richard B. Lynn, MD, FACP, Co-Editor, PIER, has no financial relationships with pharmaceutical companies, biomedical device manufacturers, or health-care related organizations. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Acute Cholecystitis Top 1. Prevention Consider medical therapy and prophylactic cholecystectomy in patients with symptomatic gallstones. 1.1 Consider UDCA to dissolve symptomatic cholesterol gallstones. Recommendations • Consider prescribing oral UDCA, 8 to 12 mg/kg·d. Evidence • In a meta-analysis of trials published from 1966 to 1992 comprising 1949 patients, complete dissolution was achieved in 18.2% of patients with CDCA, 37.3% with UDCA, and 62.8% with combination therapy (1). • A double-blind, randomized, controlled study showed up to 55% partial dissolution and up to 29% complete dissolution of radiolucent gallstones with UDCA. Dissolution was most effective in stones <5 mm in diameter (2). • A randomized, double-blind study showed that in patients treated with UDCA, there was a significant reduction in biliary cholesterol concentration, formation of cholesterol crystals, and bile viscosity (3). • A 2008 meta-analysis of five randomized, controlled trials including 521 patients showed significant reduction of gallstone formation after bariatric surgery (RR, 0.43 [CI, 0.22 to 0.83]), with 8.8% of those taking UDCA developing gallstones compared with 27.7% of those taking placebo (P=0.01) (4). • In a prospective study of 1059 patients who had laparoscopic cholecystectomy for symptomatic gallstones, risk factors for developing acute cholecystitis were analyzed. Age older than 60 years, male sex, the presence of cardiovascular disease, the presence of diabetes mellitus, and a history of cerebrovascular accident (ischemic stroke or cerebral hemorrhage) were identified as independent risk factors for acute cholecystitis after multivariate analysis. Acute cholecystitis was associated with greater operative difficulty and more postoperative morbidity than chronic cholecystitis. Therefore, an early cholecystectomy was recommended for the patients with risk factors for acute cholecystitis (5). Rationale • UDCA can dissolve gallstones, decrease cholesterol crystal formation, and reduce the bile saturation index. Comments • Patients must have a functioning gallbladder, and gallstones must be radiolucent in order to use UDCA. Gallstones optimally should be <5 mm in diameter. • Significant diarrhea will develop in 5% to 10% of patients taking UDCA. • The most definitive preventive strategy for cholecystitis is cholecystectomy. Because of suboptimal response rates and prolonged time needed for dissolution, medical therapy should be reserved for patients unable to have surgery. A study comprising 177 patients concluded that UDCA does not reduce biliary symptoms in highly symptomatic patients and that early cholecystectomy is warranted in patients with symptomatic gallstones (6). 1.2 Consider diclofenac in patients with biliary colic. Recommendations • Consider administering diclofenac, 75 mg, intramuscularly in a single injection. Evidence PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 2 of 32 Acute Cholecystitis • A 2008 systematic review and meta-analysis that included seven randomized, controlled trials (n=349 patients) comparing the efficacy of NSAIDs with other analgesic agents in the treatment of biliary colic showed NSAIDs to be the analgesics of choice for biliary colic in limiting the progression of colic to acute cholecystitis (7). • A randomized, double-blind study of diclofenac showed satisfactory pain relief and decrease in progression to acute cholecystitis. Four of 27 patients treated with diclofenac developed acute cholecystitis compared with 11 of 26 placebo patients (P=0.04) (8). • A randomized, double-blind study of diclofenac vs. hyoscine for acute biliary colic showed faster and more effective pain relief in the diclofenac arm. A smaller percentage of patients in the diclofenac group (16.7%) progressed to acute cholecystitis compared with the hyoscine group (52.8%) (9). Rationale • Diclofenac provides pain relief in biliary colic and decreases the risk for acute cholecystitis. 1.3 Consider cholecystectomy for symptomatic gallstones. Recommendations • Consider laparoscopic cholecystectomy for patients with symptomatic gallstones. Evidence • A randomized, prospective study showed that in patients with biliary colic, 38% per year had recurrent biliary pain and 2% per year required cholecystectomy for significant biliary symptoms (10). • Based on simulation modeling, prophylactic cholecystectomy may decrease mortality more than conservative management in patients with symptomatic gallstones (11). • There are no randomized trials comparing cholecystectomy vs. no cholecystectomy in patients with silent gallstones. Further evaluation of observational studies, which measure such outcomes as obstructive jaundice, gallstone-associated pancreatitis, and/or gallbladder cancer for sufficient duration of follow-up, is necessary before randomized trials are designed to evaluate whether cholecystectomy or no cholecystectomy is better for asymptomatic gallstones (12). • The need for cholecystectomy was demonstrated in a study comparing outcomes in nongangrenous (n=174) vs. gangrenous cholecystitis (n=106). Mortality was significantly higher in the latter group (0% vs. 4%; P=0.017). The risk factors associated with gangrenous cholecystitis included older age (69 years vs. 57 years; P=0.001) and diabetes (19% vs. 10%; P=0.049). There was no overall difference in complication rates between the non-gangrenous and gangrenous cholecystitis groups (22% vs. 14%; P=0.102) when treated in a specialized unit (13). Rationale • A large percentage of patients with symptomatic gallstones will have recurrent symptoms and may develop more serious complications. Comments • Surgical removal of the gallbladder and gallstones is the definitive therapy for preventing acute cholecystitis. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 3 of 32 Acute Cholecystitis Top 2. Diagnosis Base the diagnosis of acute cholecystitis on the history, physical exam, laboratory data, and radiologic studies. 2.1 Obtain patient history for features suggestive of acute cholecystitis. Recommendations • Ask about: Details of pattern, duration, location, and radiation of pain Related symptoms, such as fever, chills, nausea, or vomiting Dark urine Previous biliary colic Patient's age Presence of diabetes • Note that the typical pain is mid-epigastric, progressing to right upper quadrant. Pain may also radiate to right scapula, right shoulder, back, or lower abdomen. Evidence • A retrospective study showed that 73.5% of patients with acute cholecystitis had pain persisting less than 24 hours, 54% had right upper quadrant pain, and 34% had mid-epigastric pain (14). • A prospective study showed that 32.2% of patients with acute cholecystitis had fever, and 75% had previous episodes of biliary colic (15). • A retrospective study showed that in acute acalculous cholecystitis, advanced age was associated with the presence of severe gallbladder complications (16). • A retrospective study showed that a history of diabetes was significantly associated with the development of gangrenous cholecystitis (17). Rationale • The history of acute cholecystitis often includes previous episodes of biliary colic, mid-epigastric visceral pain radiating to the right upper quadrant, parietal pain, fever, chills, nausea, and vomiting. • Advanced age may correlate with the development of complications in acute cholecystitis. • Diabetes may play a role in the development of complications in acute cholecystitis. Comments • In elderly patients (especially those with diabetes) with leukocytosis and acute cholecystitis, consider early surgical evaluation owing to the increased risk for developing gallbladder complications (16). 2.2 Perform physical exam for features suggestive of acute cholecystitis. Recommendations • Look for: Abdominal tenderness Murphy's sign (palpation of the right upper quadrant causing pain and arrest of inspiration) Right upper quadrant mass Fever Jaundice Peritoneal signs Signs of hemodynamic instability PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 4 of 32 Acute Cholecystitis Evidence • A retrospective study showed that a positive Murphy's sign had a sensitivity of 97.2% and was highly predictive (93.3%) of a positive hepatobiliary scintigraphic scan in the diagnosis of acute cholecystitis (14). • A retrospective study showed that 85% of patients with acute cholecystitis had right upper quadrant tenderness, and 40% had tenderness elicited in other regions (18). • A retrospective study showed that 23% of patients with acute cholecystitis had a palpable gallbladder (19). Rationale • Classic findings on the exam of acute cholecystitis include right upper quadrant or mid-epigastric tenderness with Murphy's sign. • A right upper quadrant mass (palpable gallbladder) may be present. • Peritoneal signs imply a perforated viscus. Comments • Peritoneal signs require immediate surgical evaluation. 2.3 Recognize the clinical setting of acute acalculous cholecystitis. Recommendations • Consider the diagnosis of acute acalculous cholecystitis in critically ill patients. • Understand that the classic signs and/or symptoms of acute cholecystitis may be absent in acalculous disease. Evidence • A retrospective study showed that 14% of all cases of acute cholecystitis were acalculous; 63% of the patients had had surgery, 52% were in the ICU, 37% were on a ventilator, 33% were hypotensive, 33% were fasting, and 18% were on TPN (20). • A retrospective study showed that only 66.7% of patients with acute acalculous cholecystitis had right upper quadrant pain (21). Rationale • Five percent to 15% of cases of acute cholecystitis are acalculous. • Acute acalculous cholecystitis generally occurs in critically ill, septic patients. • The classic findings of right upper quadrant pain, Murphy's sign, and fever may be absent in intubated, unresponsive patients. 2.4 Use laboratory data to establish the diagnosis. Recommendations • • • • Look for evidence of leukocytosis. Evaluate LFTs. Use laboratory data to exclude other diseases. See table Laboratory and Other Studies for Acute Cholecystitis. Evidence • A prospective study showed that 41% of patients with acute cholecystitis had elevated bilirubin levels, 26% had elevated alkaline phosphatase levels, 12% had elevated ALT levels, and 51% had leukocytosis (>10,000 103/µL) (15). • A prospective study showed that 29% of patients with acute cholecystitis had hyperbilirubinemia. The average bilirubin level in patients without common bile-duct stones was 2.7 mg/dL. The average bilirubin level in patients with common bile-duct stones was 6.7 mg/dL (22). • Two retrospective studies showed that leukocytosis was present in 60% and 63% of patients with acute cholecystitis (14; 23). PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 5 of 32 Acute Cholecystitis • In a review of 216 patients with acute calculous cholecystitis, elevated serum γ-glutamyl transpeptidase >90 U/L was associated with a 33% chance of having choledocholithiasis (24). • In a retrospective review of 177 patients aged 16 to 65 years who had right hypochondrial pain, statistically significant predictors of acute cholecystitis were alkaline phosphatase, Murphy's sign, elevated leukocyte count, and elevated bilirubin level (25). Rationale • Leukocytosis, mild LFT abnormalities, and mild hyperbilirubinemia are common in acute cholecystitis. • Leukocytosis may correlate with outcome in acute cholecystitis. • Bilirubin >4 mg/dL is not a feature of uncomplicated acute cholecystitis. Comments • Bilirubin levels >4 mg/dL suggest possible common bile-duct stone, cholangitis, or Mirizzi's syndrome, a rare condition in which a gallstone impacting the cystic duct obstructs the common bile duct by edema and extrinsic compression. • In elderly patients with acute cholecystitis and leukocytosis, consider early surgical evaluation owing to the increased risk for developing gallbladder complications (16; 17). 2.5 Use imaging studies to establish the diagnosis. Recommendations • Obtain the following: Transcutaneous ultrasound to diagnose acute cholecystitis Cholescintigraphy scans (e.g., HIDA scan) as an alternative to diagnose acute cholecystitis or when ultrasound is equivocal CT scan when other studies are equivocal or when complications of acute cholecystitis are suspected MRCP scan if there is suspicion of calculi in the bile duct • • • • • See See See See See table Laboratory and Other Studies for Acute Cholecystitis. figure Gallbladder Ultrasound Showing Gallstones. figure Acalculous Cholecystitis. figure Normal Gallbladder Ultrasound. figure Gallstone Ileus. Evidence • A prospective study showed that when ultrasound revealed gallstones and a positive sonographic Murphy's sign, the positive predictive value for acute cholecystitis was 92.2%. When the patient had gallstones and gallbladder-wall thickening (≥3 mm), the positive predictive value was 95.2% for acute cholecystitis (26). • Multiple (>20) prospective and retrospective studies have showed ultrasound to have 81% to 98% sensitivity and 70% to 98% specificity for acute cholecystitis (26; 27; 28; 29; 30). • Various retrospective and prospective trials have compared ultrasound with HIDA scanning for the diagnosis of acute cholecystitis. A retrospective analysis of patients with acute cholecystitis showed ultrasound scans to be less sensitive than HIDA scans for initial diagnosis (48% vs. 86%) (30). • A retrospective study showed ultrasound to have a sensitivity of 86% vs. 97% for HIDA scans (28). • A retrospective study showed ultrasound to have an accuracy of 94% vs. 93% for HIDA scans (27). • A meta-analysis from 1994 of 30 articles showed ultrasound to have 94% sensitivity and 78% specificity, compared with HIDA scans, which have a 97% sensitivity and a 90% specificity for the diagnosis of acute cholecystitis (29). • A retrospective study showed that 50.9% of patients with acute cholecystitis showed evidence of a thickened gallbladder wall on unenhanced CT scan. In addition, 66.7% of patients with this finding had gangrenous cholecystitis on histology (31). • A 2003 meta-analysis of 67 studies including 4711 patients showed that MRCP is a non-invasive imaging test with excellent overall sensitivity (95%) and specificity (97%) for showing the level PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 6 of 32 Acute Cholecystitis and presence of biliary obstruction, although it was less sensitive for identifying stones (88%) and malignant lesions (92%) (32). Rationale • Both ultrasound and HIDA scans are accurate for the diagnosis of acute cholecystitis. The general recommendation has been to obtain an ultrasound scan first, followed by an HIDA scan, if necessary. • The classic findings of acute cholecystitis on ultrasound are pericholecystic fluid and a thickened gallbladder wall of 3 mm to 4 mm; sonographic Murphy's sign further confirms the diagnosis. • The classic finding of acute cholecystitis on HIDA scan is non-visualization of the gallbladder. • An enhanced CT scan can show gallstones, gallbladder-wall thickening, gallbladder distension, pericholecystic fluid, and inflammation of the pericholecystic fat. An unenhanced CT scan can show gallstones and a hyperdense gallbladder wall, which can suggest the presence of gangrenous cholecystitis. Comments • Despite most organizations recommending ultrasound as the primary diagnostic tool for acute cholecystitis, the literature shows that an HIDA scan has equal or better sensitivity and specificity; however, cost and ease of access favor the use of ultrasound. • Ultrasound can be less accurate in patients with ascites, hypoalbuminemia, hepatitis, obesity, and heart failure. • HIDA scans can give false-positive results in critically ill, fasting patients. Furthermore, HIDA scans are not accurate with bilirubin levels >5 mg/dL, in which case more specialized tests, such as DISIDA scan, can be used. • CT scan should be reserved for cases of diagnostic dilemma and to detect possible complications of acute cholecystitis (31). • MRCP is commonly used to diagnose obstruction of the biliary tree caused by stones or malignant lesions. 2.6 Consider the broad differential diagnosis. Recommendations • When considering the differential diagnosis of acute cholecystitis, include acute disease processes on both sides of the diaphragm. • See table Differential Diagnosis of Acute Cholecystitis. Evidence • Consensus. Rationale • Many intra-abdominal and thoracic conditions can mimic acute cholecystitis. • The correct diagnosis must be made to separate routine conditions from emergent conditions. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 7 of 32 Acute Cholecystitis Top 3. Consultation Obtain surgical and possibly GI consultation to aid in the diagnosis. Consult a surgeon and a gastroenterologist as needed for management of patients. 3.1 Obtain surgical consultation for suspected cases of acute cholecystitis. Recommendations • Obtain surgical consultation to aid in diagnosing acute calculous and acalculous cholecystitis. Evidence • Consensus. Rationale • The differential diagnosis of acute cholecystitis is extensive; several surgical conditions can mimic acute cholecystitis. • Acute acalculous cholecystitis can present with subtle signs and symptoms in critically ill patients. • A surgical consultant can establish a diagnosis and formulate a treatment plan. 3.2 Obtain GI consultation in certain cases. Recommendations • Obtain GI consultation in cases of suspected acute cholecystitis with a bilirubin level >4 mg/dL and/or significantly elevated LFTs. Evidence • A prospective study of patients with acute cholecystitis who had hyperbilirubinemia and subsequent biliary-tract exploration showed that 68.4% had common bile-duct stones (22). Rationale • Acute cholecystitis is generally not associated with significant jaundice or elevation of LFTs; these findings suggest either common bile-duct stones or Mirizzi's syndrome, a rare condition in which a gallstone impacting the cystic duct obstructs the common bile duct by edema and extrinsic compression. • MRC is useful in detecting stones in the common bile duct before or after cholecystectomy and may be indicated. • Endoscopic evaluation of the biliary tree may be warranted. 3.3 Obtain joint surgical and obstetric consultations in cases of suspected acute cholecystitis during pregnancy. Recommendations • Obtain joint surgical and obstetric consultations in cases of suspected acute cholecystitis during pregnancy. Evidence • In a study of 6221 women with gallstone-related hospitalization during pregnancy and postpartum, 76% were diagnosed with uncomplicated cholelithiasis, 16% with pancreatitis, 9% with acute cholecystitis, and 8% with cholangitis. Seventy-three percent of the hospitalized women underwent cholecystectomy and 5% underwent ERCP (39). • In a prospective observational study of 122 patients with biliary disease (41 with acute cholecystitis), conservative treatment failed in 69 (56.5%) patients and 54 of this group underwent laparoscopic cholecystectomy during second trimester with no fetal or maternal mortality (40). PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 8 of 32 Acute Cholecystitis • In a study of 49 patients admitted with an acute abdomen in pregnancy due to cholecystitis, 15 patients (31%) had emergency cholecystectomy within the first week. Thirty-four patients (69%) were treated conservatively, of whom 24 relapsed many times and had to be readmitted to the hospital. Of the remaining 10 patients on conservative management, 3 had emergency cholecystectomy and 7 reached term safely. Maternal morbidity was significantly less in the surgically treated group (P<0.0001), but there was no significant difference in perinatal outcome. Although tocolytics were used in 13 cases, they did not improve the fetal outcome significantly and had maternal and fetal side effects. This article concluded that early surgical intervention is recommended and the use of tocolytics did not improve the perinatal outcome (41). • In a population-based measurement of outcomes of cholecystectomy during pregnancy among 9714 pregnant women (89% underwent laparoscopic cholecystectomy), maternal and fetal complication rates were 4.3% and 5.8%, respectively. Compared with pregnant women who underwent open procedures, pregnant women who underwent laparoscopic cholecystectomy had higher rates of surgical (19% vs. 10%), maternal (9% vs. 4%), and fetal (11% vs. 5%) complications; longer length of stay (6 vs. 4 days); and higher cost ($13,198 vs. $9,229) (all P<0.0001) (42). Rationale • Acute cholecystitis during pregnancy, although classically managed conservatively, can be associated with recurrent symptoms requiring cholecystectomy. • Acute cholecystitis during pregnancy can be safely treated with minimally invasive techniques including percutaneous aspiration, cholecystostomy, laparoscopic cholecystectomy, and ERCP, depending on the pregnancy trimester and underlying diagnosis. 3.4 Consult a surgeon immediately for management of patients. Recommendations • Consult a surgeon immediately for cholecystectomy. • Consider surgical consult even in patients who are poor surgical candidates or deemed inoperable who may benefit from cholecystectomy. Evidence • A prospective, randomized trial compared early cholecystectomy with delayed cholecystectomy in patients with acute cholecystitis. In the delayed group, 13% of patients required emergent surgery within 90 days owing to cholangitis, empyema, or peritonitis. Another 15% of patients developed acute recurrent symptoms within the 90-day period (54). • Two prospective, randomized, controlled trials have examined the issue of ‘early’ vs. ‘delayed’ laparoscopic cholecystectomy in acute cholecystitis. Both showed no difference in complication rates, rates of conversion to open procedure, morbidity, or mortality. There was a shorter hospital stay in the early group (P<0.001) (75; 76). • A retrospective Veterans Administration study of acute cholecystitis patients with multiple medical comorbidities evaluated 24 patients treated with cholecystostomy tubes (22 ultrasound/CT guided, 2 surgically placed), of whom 78% had clinical improvement within 48 hours. There was a 25% periprocedural mortality rate (77). • A retrospective study of inoperable patients treated with percutaneous cholecystostomy showed 98% successful biliary drainage; 96% of these patients showed clinical improvement within 72 hours, and 93% were discharged from the hospital with plans for a subsequent cholecystectomy (65). • A prospective study showed that 92.3% of patients with acute acalculous cholecystitis treated with percutaneous cholecystostomy had good clinical response. All patients had subsequent catheter removal without the need for cholecystectomy (66). • A prospective study showed that 93.3% of patients with acute acalculous cholecystitis treated with percutaneous cholecystostomy had significant clinical improvement; 13 of 14 patients who responded had catheter removal and required no further therapy (67). PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 9 of 32 Acute Cholecystitis Rationale • Cholecystectomy is definitive therapy in most patients with acute cholecystitis. • Early laparoscopic cholecystectomy can be safely done in most patients with acute cholecystitis. • Inoperable and high-risk surgical candidates may need interventions, such as cholecystostomy, which can be coordinated by a surgical consultant. 3.5 Consult a gastroenterologist in certain cases. Recommendations • Consult a gastroenterologist in patients for possible ERCP with acute cholecystitis and: Jaundice Common bile-duct dilation Significantly elevated LFT levels Significantly elevated pancreatic enzymes Evidence • A prospective, randomized study showed that 100% of patients presenting with acute cholangitis had successful biliary drainage by ERCP. There was a trend toward fewer complications in the ERCP group vs. the surgery group (P>0.05), and there was less mortality in the ERCP group (P<0.03) (78). • A retrospective study showed that 97% of patients with acute cholangitis were able to have successful biliary drainage by ERCP. The overall mortality was 4.7% (compared with the quoted historical, surgical mortality rate of 16.5% to 40%) (79). Rationale • Patients with acute cholecystitis and significantly elevated LFTs, bilirubin, pancreatic enzymes, or dilated bile ducts may have common bile-duct stones or Mirizzi's syndrome. • ERCP may be diagnostic and/or therapeutic in this subset of patients. Comments • MRC is a non-invasive method of detecting stones in the common bile duct in patients with risk factors for common bile-duct calculi, thereby helping avoid ERCP, which is an invasive test with potential complications. A prospective study evaluated the predictive value of MRC in detecting stones in the common bile duct before laparoscopic cholecystectomy. MRC had a sensitivity of 100%, a specificity of 96.3%, a positive predictive value of 91.8%, and a negative predictive value of 100% for the detection of common bile-duct stones (80). PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 10 of 32 Acute Cholecystitis Top 4. Hospitalization Hospitalize patients with acute cholecystitis. 4.1 Hospitalize patients with acute cholecystitis for definitive diagnosis and treatment. Recommendations • Hospitalize patients to: Provide analgesia, hydration, supportive care, and possibly antibiotics Obtain surgical consultation Prepare patient for possible cholecystectomy • See Therapy. Evidence • Consensus. Rationale • Many patients with acute cholecystitis will have nausea, vomiting, or anorexia requiring iv hydration and supportive care, and many will also require parenteral analgesia. • Most patients will require definitive surgical therapy. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 11 of 32 Acute Cholecystitis Top 5. Therapy Consider cholecystectomy as definitive therapy. 5.1 Consider the use of antibiotics in certain patients. Recommendations • Consider using broad-spectrum antibiotics in acute cholecystitis patients with sepsis, fever, leukocytosis, or evidence of complications. • See table Drug Treatment for Acute Cholecystitis. Evidence • A prospective study of 467 patients with acute cholecystitis showed positive bile cultures in 46%; the most common organisms were E. coli, Klebsiella sp., group D Streptococcus sp., and Enterobacter sp. Patients aged over 60 years had the highest rate of biliary infection (43). • Cases of acute cholecystitis are reported to be caused by such organisms as Vibrio cholerae (44), Haemophilus influenzae (45), Moellerella wisconsensis (46), Salmonella sp. (47), Cytomegalovirus (48), Cellulomonas denverensis (49), and Candida lusitaniae (50). • A retrospective study of 302 patients with acute cholecystitis showed no difference in local septic complications, such as empyema or pericholecystic abscess, in those treated with or without antibiotics. There was a lower incidence of wound infections and postoperative bacteremia in patients treated with antibiotics (51). Rationale • A significant percentage of patients with acute cholecystitis will have positive blood and bile cultures. Antibiotics would be expected to benefit this group. Comments • Definitive evidence regarding the use of antibiotics in acute cholecystitis is lacking; however, it would seem prudent to consider using antibiotics in toxic-appearing patients. • The recommended regimens vary from single- to triple-coverage; the choice of antibiotic should be based on suspected organisms and local antibiotic resistance patterns. 5.2 Ensure appropriate use of pain medications. Recommendations • Consider using: NSAIDs in patients with biliary colic or acute cholecystitis with mild to moderate abdominal pain Narcotic analgesics in patients with moderate to severe abdominal pain • See module Pain. Evidence • Retrospective studies of patients presenting with acute cholecystitis show that abdominal pain occurs in 73.5% (14) and abdominal tenderness occurs in 85% (18). • A randomized, double-blind study of diclofenac showed satisfactory pain relief and decrease in progression to acute cholecystitis. Four of 27 patients who received diclofenac developed acute cholecystitis compared with 11 of 26 patients who received placebo (P=0.04) (8). • A 2008 systematic review and meta-analysis that included seven randomized, controlled trials (n=349 patients) assessing the efficacy of NSAIDs in comparison to other analgesic agents in the treatment of biliary colic showed NSAIDs to be the analgesics of choice for biliary colic in limiting the progression of colic to acute cholecystitis (7). • A randomized, double-blind study evaluated the efficacy of iv ketorolac compared with butorphanol for the treatment of biliary colic pain in the emergency department. Patients presenting with abdominal pain suspected to be biliary colic were randomized to receive either ketorolac, 30 mg iv, PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 12 of 32 Acute Cholecystitis or butorphanol, 1 mg iv. The mean (+/- SD) pain score (visual analogue scale) in the butorphanol group decreased from 7.1 (+/-1.7) to 2.1 (+/-2.2) after 30 minutes. The mean (+/-SD) pain score in the ketorolac group decreased from 7.4 (+/-2.0) to 3.1 (+/-3.3) after 30 minutes. This study showed that both ketorolac and butorphanol provide pain relief in biliary colic and were suitable especially in patients who require HIDA scan (52). Rationale • Over 80% of patients with acute cholecystitis present with abdominal pain or tenderness, and pain medications can provide analgesia while awaiting definitive therapy. • NSAIDs provide pain relief in biliary colic and may decrease the risk for progression to acute cholecystitis. Comments • A prospective, non-blinded study using sphincter of Oddi manometry showed that morphine increased sphincter phasic wave amplitude and basal pressure (P<0.05) (53). • Older studies suggested that meperidine might be preferable to morphine in the treatment of pain in patients with acute cholecystitis because it increases pressure at the sphincter of Oddi less than other opiates, but evidence is not strong enough to support a recommendation of one opiate analgesic over another. Meperidine should be avoided in elderly patients and those with renal dysfunction because of possible accumulation of a toxic metabolite with neuroexcitatory effects. 5.3 Consider early cholecystectomy. Recommendations • Consider laparoscopic cholecystectomy to be the preferred surgical approach in patients with acute cholecystitis. • Perform cholecystectomy within 24 to 48 hours of diagnosis. • Note that technical aspects, such as anatomy and complications, may require an open surgical approach in certain patients. Evidence • A prospective, randomized trial compared early cholecystectomy with delayed cholecystectomy in patients with acute cholecystitis. In the delayed group, 13% of patients required emergent surgery within 90 days owing to cholangitis, empyema, or peritonitis. Another 15% of patients developed acute recurrent symptoms within the 90-day period (54). • A retrospective study evaluated 609 patients with acute cholecystitis treated by laparoscopic cholecystectomy. The overall complication rate was 15%; specific complication rates were bile leaks, 1.97%, and biliary-tract injury, 0.66%; mortality was 0.66%. These rates were comparable to previous open cholecystectomy series (55). • A randomized, controlled trial comparing open and laparoscopic cholecystectomy in acute cholecystitis showed a significantly lower postoperative complication rate (P=0.0048), shorter hospitalization (P=0.0063), and lower hospital cost for laparoscopy (56). • A 2008 meta-analysis examined the issue of ‘early’ vs. ‘delayed’ laparoscopic cholecystectomy in patients with acute cholecystitis. Early laparoscopic cholecystectomy resulted in a significantly shorter total hospital stay at the cost of a significantly longer operation time, with no significant difference in conversion rates or complications (57). • A 2010 systematic review with meta-analysis of randomized clinical trials of early laparoscopic cholecystectomy (done within 1 week of onset of symptoms) vs. delayed laparoscopic cholecystectomy (done at least 6 weeks after symptoms settled) for acute cholecystitis, which included five trials with 451 patients, showed no significant difference between the two groups in terms of bile-duct injury (RR, 0.64 [CI, 0.15 to 2.65]) or conversion to open cholecystectomy (RR, 0.88 [CI, 0.62 to 1.25]). The total hospital stay was 4 days shorter for early laparoscopic cholecystectomy (mean difference, -4.12 [CI, -5.22 to -3.03] days). Early laparoscopic cholecystectomy during acute cholecystitis appears safe and shortens the total hospital stay (58). PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 13 of 32 Acute Cholecystitis • A 2008 Cochrane review, which included five trials with 429 patients randomly assigned to the daycase group (n=215) and overnight-stay group (n=214), showed no significant difference between the two groups regarding morbidity, prolongation of hospital stay, readmission rates, pain, quality of life, patient satisfaction, and return to normal activity and work. The day-case elective laparoscopic cholecystectomy was safe and effective in selected patients with symptomatic gallstones who had no or minimal systemic disease and were within easy reach of the hospital (59). • In a prospective study from the UK that included 106 patients who had day-case laparoscopic cholecystectomy, 84% were discharged on the day of surgery. Mean surgery time was 62 minutes, with an average total stay on the day-case unit of 426 minutes. Both the readmission rate after surgery and rate of conversion to open surgery were 2%. Introduction of day-case laparoscopic cholecystectomy in the UK was feasible and acceptable to patients (60). • Cholecystectomy using rigid-hybrid transvaginal natural orifice transluminal endoscopic surgery reduces abdominal-wall incisions and might decrease surgical trauma by combining endoluminal access and laparoscopic techniques. In one study, 102 of 137 consecutive patients (74.5 %) with symptomatic cholecystolithiasis (n=74) or cholecystitis (n=28) were scheduled for this type of surgery. There were no intraoperative complications. At 6 weeks postoperatively, there were fewer dyspareunia symptoms than preoperatively (P=0.049). This technique is feasible and safe in routine practice for symptomatic cholecystolithiasis and acute cholecystitis (61). • Percutaneous transhepatic gallbladder drainage is a procedure to resolve acute cholecystitis, which decreases the technical difficulty of laparoscopic cholecystectomy and facilitates successful surgery when a patients' condition improves. Early laparoscopic cholecystectomy (within 72 hours, n=21) vs. delayed (after 72 hours; n=46) laparoscopic cholecystectomy after percutaneous transhepatic gallbladder drainage showed a higher complication rate and longer operating time, but shorter hospital stay in the former group (62). • In a retrospective study involving 809 patients with acute cholecystitis, laparoscopic cholecystectomy (done in 82% of patients) was associated with significantly better outcomes, including shorter postsurgical stay and fewer complications compared with open cholecystectomy and cholecystostomy (63). Rationale • Laparoscopic cholecystectomy is safer, less expensive, and associated with shorter hospitalizations than open procedures. • Early cholecystectomy is associated with a shorter recovery period and fewer complications, such as gangrene and empyema of the gallbladder. • Acute cholecystitis and/or other serious complications of gallstone disease can recur in untreated patients. Comments • The exact surgical approach may vary based on local surgical expertise. • Patients should understand that conversion from a laparoscopic to an open procedure may be necessary. • Day-case laparoscopic cholecystectomy is not suitable for acute cholecystitis. • Natural orifice transluminal endoscopic surgery is being increasingly practiced with encouraging results. • Single-incision laparoscopic cholecystectomy is a variation in which trocar scars are hidden in the umbilicus. In a study including 205 cases of single-incision laparoscopic cholecystectomy, the mean operating time was 60 minutes and complications occurred in 4% of cases. Single-incision laparoscopic cholecystectomy can be done safely and offers a better cosmetic result, which may lead to greater patient satisfaction (64). 5.4 Consider cholecystostomy in certain patients. Recommendations PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 14 of 32 Acute Cholecystitis • Consider cholecystostomy as temporizing or definitive therapy for inoperable or high-risk patients with calculous or acalculous cholecystitis. Evidence • A retrospective study of inoperable patients treated with percutaneous cholecystostomy showed 98% successful biliary drainage; 96% of these patients showed clinical improvement within 72 hours, and 93% were discharged from the hospital with plans for a subsequent cholecystectomy (65). • A prospective study showed that 92.3% of patients with acute acalculous cholecystitis treated with percutaneous cholecystostomy had good clinical response. All patients had subsequent catheter removal without the need for cholecystectomy (66). • A prospective study showed that 93.3% of patients with acute acalculous cholecystitis treated with percutaneous cholecystostomy had significant clinical improvement; 13 of 14 patients who responded had catheter removal and required no further therapy (67). • A retrospective study of 45 patients having cholecystostomy for acute cholecystitis showed a 100% technically successful gallbladder drainage rate. 78% of the patients improved clinically within 5 days (68). • A prospective study randomizing patients with acute calculous cholecystitis into those having percutaneous cholecystostomy followed by an early laparoscopic cholecystectomy (n=31) and those having an initial conservative treatment followed by a delayed laparoscopic cholecystectomy (n=30) showed significantly shorter hospital stay and lower cost in the first group (69). • In a study involving 106 patients with acute cholecystitis, percutaneous cholecystostomy led to clinical improvement in 72 patients (68%), whereas 34 (32%) showed no improvement or clinical deterioration. Patients who presented to the emergency department primarily with acute cholecystitis fared better (84% of patients showed improvement) than inpatients (34% showed improvement; P<0.0001). Gallstones were identified in 54% of patients who presented to the emergency department, whereas acalculous cholecystitis was more commonly diagnosed in inpatients (54%). Patients with sepsis had worse outcomes overall (P<0.0001). Patients fare better after percutaneous cholecystostomy for acute cholecystitis when the disease is primary and not precipitated by concurrent illness (70). Rationale • The mortality rate of critically ill patients having cholecystectomy for acute cholecystitis can be 10% to 30%. • Because patients with acute acalculous cholecystitis are often critically ill and may not be operative candidates, cholecystostomy may allow biliary drainage that may temporize the patient until surgery can be safely done or even provide definitive therapy for the patient. • Acalculous cholecystitis may resolve when the precipitating factors, such as TPN, sepsis, shock, or fasting, improve. • Cholecystostomy may allow time to resolve these precipitating factors and thus be curative. Comments • Cholecystostomy is indicated in high-risk patients who are not candidates for cholecystectomy. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 15 of 32 Acute Cholecystitis Top 6. Patient Education Inform patients of the natural history of acute cholecystitis. 6.1 Inform patients of the natural history and therapeutic options for acute cholecystitis. Recommendations • Explain the natural course of acute cholecystitis. • Inform the patient of the treatment options available. • Explain why surgical options are preferred in most cases. Evidence • A retrospective study of patients at initial presentation with acute cholecystitis showed 7.1% had gangrenous cholecystitis, 6.3% had empyema of the gallbladder, 3.3% had gallbladder perforation, and 0.5% had emphysematous cholecystitis (71). • A prospective, randomized trial compared early cholecystectomy with delayed cholecystectomy in patients with acute cholecystitis. In the delayed group, 13% of patients required emergent surgery within 90 days owing to cholangitis, empyema, or peritonitis. Another 15% of patients developed acute recurrent symptoms within the 90-day period (54). • A prospective, randomized clinical trial compared the outcomes of early (within 7 days of onset of symptoms) with delayed (6 to 8 weeks after initial conservative treatment) laparoscopic cholecystectomy. Twenty-six percent of patients in the delayed cholecystectomy group required emergency cholecystectomy for failure of conservative treatment. There was no significant difference in the conversion rate, operating time, or complications. The greatest advantage was a reduced length of hospital stay in the early cholecystectomy group (72). • A 2008 meta-analysis of 20 randomized, controlled trials including 3860 patients showed day-case laparoscopic cholecystectomy to be safe in a selected group of patients who do not have acute cholecystitis, bile-duct stones, or previous upper-abdominal surgery (73). • In 185 adult patients admitted with acute cholecystitis (mean age 71 years; 80% had more than one comorbidity), percutaneous cholecystostomy was done in 78% of cases and open surgical cholecystostomy was done in 22%. In both groups, 85% patients underwent laparoscopic cholecystectomy as definitive treatment, thereby confirming that cholecystostomy is a useful alternative to open cholecystectomy in patients with acute cholecystitis that allows patients to undergo laparoscopic cholecystectomy at a later date (74). Rationale • The risk for advanced disease and complications at the time of presentation is significant. • The risk for recurrent acute cholecystitis in the untreated patient is significant. • Surgical therapies are definitive, effective, and safe. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 16 of 32 Acute Cholecystitis Top 7. Follow-up Schedule follow-up of patients treated for acute cholecystitis based on hospital course. 7.1 Ensure that patients who have had cholecystectomy follow-up with their surgeon. Recommendations • Advise patients to follow-up with their surgeon routinely, and immediately if they have right upper quadrant pain, fever, or wound-site complaints which suggest postoperative biliary tract complications such as retained bile-duct stone, bile leak, or infection. Evidence • Two prospective, randomized studies showed overall complication rates of 13% (75) and 9% (76) in patients having early laparoscopic cholecystectomy for acute cholecystitis. • A retrospective literature review showed that the overall risk for biliary injury during laparoscopic cholecystectomy (for any indication) is 2.58%; major bleeding occurred in 1.38% of cases, wound infection in 0.6%, bile leak in 0.4%, biliary injury in 0.2%, and bowel injury in 0.16% (81). A retrospective, single-center study showed bile-duct injury occurring in 0.59% of patients having laparoscopic cholecystectomy for any indication (82). Rationale • Laparoscopic cholecystectomy carries risk for postoperative complications; these risks are higher in patients having the procedure for acute cholecystitis. • The surgeon should watch for signs and symptoms of biliary-tract complications and wound infections. Comments • The surgeon should determine the postoperative follow-up schedule. 7.2 Re-evaluate patients who have had cholecystostomy or medical management. Recommendations • In consultation with a surgeon, re-evaluate patients with acute cholecystitis who have had: Cholecystostomy or medical therapy alone for subsequent cholecystectomy Medical therapy with UDCA to dissolve remaining symptomatic gallstones ERCP with or without sphincterotomy to remove a retained bile-duct stone • Ask about recurrent symptoms of right upper quadrant pain and biliary colic, fever, and jaundice. Evidence • A prospective, randomized trial compared early cholecystectomy with delayed cholecystectomy in patients with acute cholecystitis. In the delayed group, 13% of patients required emergent surgery within 90 days owing to cholangitis, empyema, or peritonitis. Another 15% of patients developed acute recurrent symptoms within the 90-day period (54). • A retrospective study showed that 61.5% of patients with acute calculous cholecystitis who were temporized with a cholecystostomy tube were able to have subsequent elective cholecystectomy. Surgical morbidity was 12.5% with no mortalities (83). Rationale • Many patients treated conservatively for acute calculous cholecystitis will have recurrent significant complications. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 17 of 32 Acute Cholecystitis • Cholecystectomy provides definitive therapy. Comments • Extremely poor-risk surgical candidates can be maintained with a permanent cholecystostomy drainage tube. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 18 of 32 Acute Cholecystitis Top References 1. May GR, Sutherland LR, Shaffer EA. Efficacy of bile acid therapy for gallstone dissolution: a meta-analysis of randomized trials. Aliment Pharmacol Ther. 1993;7:139-48. (PMID: 8485266) 2. Erlinger S, Le Go A, Husson JM, Fevery J. Franco-Belgian cooperative study of ursodeoxycholic acid in the medical dissolution of gallstones: a double-blind, randomized, dose-response study, and comparison with chenodeoxycholic acid. Hepatology. 1984;4:308-14. (PMID: 6706305) 3. Fischer S, Muller I, Zundt BZ, Jungst C, Meyer G, Jungst D. Ursodeoxycholic acid decreases viscosity and sedimentable fractions of gallbladder bile in patients with cholesterol gallstones. Eur J Gastroenterol Hepatol. 2004;16:305-11. (PMID: 15195895) 4. Uy MC, Talingdan-Te MC, Espinosa WZ, Daez ML, Ong JP. Ursodeoxycholic acid in the prevention of gallstone formation after bariatric surgery: a meta-analysis. Obes Surg. 2008;18:1532-8. (PMID: 18574646) 5. Cho JY, Han HS, Yoon YS, Ahn KS. Risk factors for acute cholecystitis and a complicated clinical course in patients with symptomatic cholelithiasis. Arch Surg. 2010;145:329-33; discussion 333. (PMID: 20404281) 6. Venneman NG, Besselink MG, Keulemans YC, Vanberge-Henegouwen GP, Boermeester MA, Broeders IA, et al. Ursodeoxycholic acid exerts no beneficial effect in patients with symptomatic gallstones awaiting cholecystectomy. Hepatology. 2006;43:127683. (PMID: 16729326) 7. Basurto Oña X, Robles Perea L. [Anti-inflammatory drugs for biliary colics: systematic review and meta-analysis of randomized controlled trials.] Gastroenterol Hepatol. 2008;31:1-7. (PMID: 18218271) 8. Akriviadis EA, Hatzigavriel M, Kapnias D, Kirmlidis J, Markantas A, Garyfallos A. Treatment of biliary colic with diclofenac: a randomized, double-blind, placebo-controlled study. Gastroenterology. 1997;113:225-31. (PMID: 9207282) 9. Kumar A, Deed JS, Bhasin B, Kumar A, Thomas S. Comparison of the effect of diclofenac with hyoscine-N-butylbromide in the symptomatic treatment of acute biliary colic. ANZ J Surg. 2004;74:573-6. (PMID: 15230794) 10. Thistle JL, Cleary PA, Lachin JM, Tyor MP, Hersh T. The natural history of cholelithiasis: the National Cooperative Gallstone Study. Ann Intern Med. 1984;101:171-5. (PMID: 6742647) 11. Ransohoff DF, Gracie WA. Treatment of gallstones. Ann Intern Med. 1993;119(7 Pt 1):606-19. Review. (PMID: 8363172) 12. Gurusamy KS, Samraj K. Cholecystectomy versus no cholecystectomy in patients with silent gallstones. Cochrane Database Syst Rev. 2007;(1):CD006230. (PMID: 17253585) 13. Nikfarjam M, Niumsawatt V, Sethu A, Fink MA, Muralidharan V, Starkey G, et al. Outcomes of contemporary management of gangrenous and non-gangrenous acute cholecystitis. HPB (Oxford). 2011;13:551-8. (PMID: 21762298) 14. Singer AJ, McCracken G, Henry MC, Thode HC Jr, Cabahug CJ. Correlation among clinical, laboratory, and hepatobiliary scanning findings in patients with suspected acute cholecystitis. Ann Emerg Med. 1996;28:267-72. (PMID: 8780468) 15. Raine PA, Gunn AA. Acute cholecystitis. Br J Surg. 1975;62:697-700. (PMID: 1174813) 16. Wang AJ, Wang TE, Lin CC, Lin SC, Shih SC. Clinical predictors of severe gallbladder complications in acute acalculous cholecystitis. World J Gastroenterol. 2003;9:2821-3. (PMID: 14669342) 17. Fagan SP, Awad SS, Rahwan K, Hira K, Aoki N, Itani KM, et al. Prognostic factors for the development of gangrenous cholecystitis. Am J Surg. 2003;186:481-5. (PMID: 14599611) 18. Staniland JR, Ditchburn J, De Dombal FT. Clinical presentation of acute abdomen: study of 600 patients. Br Med J. 1972;3:3938. (PMID: 4506871) 19. Halasz NA. Counterfeit cholecystitis, a common diagnostic dilemma. Am J Surg. 1975;130:189-93. (PMID: 1155733) 20. Kalliafas S, Ziegler DW, Flancbaum L, Choban PS. Acute acalculous cholecystitis: incidence, risk factors, diagnosis, and outcome. Am Surg. 1998;64:471-5. (PMID: 9585788) 21. Eggermont AM, Lameris JS, Jeekel J. Ultrasound-guided percutaneous transhepatic cholecystostomy for acute acalculous cholecystitis. Arch Surg. 1985;120:1354-6. (PMID: 3904672) 22. Dumont AE. Significance of hyperbilirubinemia in acute cholecystitis. Surg Gynecol Obstet. 1976;142:855-7. (PMID: 936028) 23. Gruber PJ, Silverman RA, Gottesfeld S, Flaster E. Presence of fever and leukocytosis in acute cholecystitis. Ann Emerg Med. 1996;28:273-7. (PMID: 8780469) 24. Peng WK, Sheikh Z, Paterson-Brown S, Nixon SJ. Role of liver function tests in predicting common bile duct stones in acute calculous cholecystitis. Br J Surg. 2005;92:1241-7. (PMID: 16078299) 25. Mills LD, Mills T, Foster B. Association of clinical and laboratory variables with ultrasound findings in right upper quadrant abdominal pain. South Med J. 2005;98:155-61. (PMID: 15759944) PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 19 of 32 Acute Cholecystitis 26. Ralls PW, Colletti PM, Lapin SA, Chandrasoma P, Boswell WD Jr, Ngo C, et al. Real-time sonography in suspected acute cholecystitis. Prospective evaluation of primary and secondary signs. Radiology. 1985;155:767-71. (PMID: 3890007) 27. Matolo NM, Stadalnik RC, McGahan JP. Comparison of ultrasonography, computerized tomography, and radionuclide imaging in the diagnosis of acute and chronic cholecystitis. Am J Surg. 1982;144:676-81. (PMID: 7149126) 28. Fink-Bennett D, Freitas JE, Ripley SD, Bree RL. The sensitivity of hepatobiliary imaging and real-time ultrasonography in the detection of acute cholecystitis. Arch Surg. 1985;120:904-6. (PMID: 3893388) 29. Shea JA, Berlin JA, Escarce JJ, Clarke JR, Kinosian BP, Cabana MD, et al. Revised estimates of diagnostic test sensitivity and specificity in suspected biliary tract disease. Arch Intern Med. 1994;154:2573-81. (PMID: 7979854) 30. Kalimi R, Gecelter GR, Caplin D, Brickman M, Tronco GT, Love C, et al. Diagnosis of acute cholecystitis: sensitivity of sonography, cholescintigraphy, and combined sonography-cholescintigraphy. J Am Coll Surg. 2001;193:609-13. (PMID: 11768676) 31. Cheng SM, Ng SP, Shih SL. Hyperdense gallbladder wall sign: an overlooked sign of acute cholecystitis on unenhanced CT examination. Clin Imaging. 2004;28:128-31. (PMID: 15050226) 32. Romagnuolo J, Bardou M, Rahme E, Joseph L, Reinhold C, Barkun AN. Magnetic resonance cholangiopancreatography: a metaanalysis of test performance in suspected biliary disease. Ann Intern Med. 2003;139:547-57. (PMID: 14530225) 33. Working Party of the British Society of Gastroenterology; Association of Surgeons of Great Britain and Ireland; Pancreatic Society of Great Britain and Ireland; Association of Upper GI Surgeons of Great Britain and Ireland. UK guidelines for the management of acute pancreatitis. Gut. 2005;54 Suppl 3:iii1-9. (PMID: 15831893) 34. Mergen H, Genç H, Tavusbay C. Assessment of liver hydatid cyst cases--10 years experience in Turkey. Trop Doct. 2007;37:54-6. (PMID: 17326896) 35. Wani I. Gallbladder ascariasis. Turk J Gastroenterol. 2011;22:178-82. (PMID: 21796555) 36. Kelly TR. Benign liver tumors: presenting profiles and treatment. Am Surg. 1981;46:398-402. (PMID: 7447174) 37. Boer J, Boerma D, de Vries Reilingh TS. A gallbladder torsion presenting as acute cholecystitis in an elderly woman: A case report. J Med Case Rep. 2012;5:588. (PMID: 22185300) 38. Choi YS. Gallbladder hemorrhage mimicking acute cholecystitis in a patient under antiplatelet therapy. Z Gastroenterol. 2012;50:285-7. (PMID: 22383284) 39. Ko CW. Risk factors for gallstone-related hospitalization during pregnancy and the postpartum. Am J Gastroenterol. 2006;101:2263-8. (PMID: 17032191) 40. Chiappetta Porras LT, Nápoli ED, Canullán CM, Quesada BM, Roff HE, Alvarez Rodríguez J, et al. Minimally invasive management of acute biliary tract disease during pregnancy. HPB Surg. 2009;2009:829020. (PMID: 19606252) 41. Elamin Ali M, Yahia Al-Shehri M, Abu-Eshy S, Cheema MA, Mustafa Z, Sadek A. Is surgical intervention in acute cholecystitis in pregnancy justified? J Obstet Gynaecol. 2004;17:435-8. (PMID: 15511915) 42. Kuy S, Roman SA, Desai R, Sosa JA. Outcomes following cholecystectomy in pregnant and nonpregnant women. Surgery. 2009;146:358-66. (PMID: 19628096) 43. Csendes A, Burdiles P, Maluenda F, Diaz JC, Csendes P, Mitru N. Simultaneous bacteriologic assessment of bile from gallbladder and common bile duct in control subjects and patients with gallstones and common duct stones. Arch Surg. 1996;131:389-94. (PMID: 8615724) 44. Vogt AP, Doshi RK, Higgins JE, Burd EM, Ribner BS, Kraft CS. Acute cholecystitis caused by nontoxigenic Vibrio cholerae O1 Inaba. J Clin Microbiol. 2010;48:1002-4. (PMID: 20053858) 45. Matsubayashi T, Tobayama S, Machida H. Acute cholecystitis caused by Haemophilus influenzae in a child. J Infect Chemother. 2009;15:325-7. (PMID: 19856072) 46. Aller AI, Castro C, Medina MJ, González MT, Sevilla P, Morilla MD, et al. Isolation of Moellerella wisconsensis from blood culture from a patient with acute cholecystitis. Clin Microbiol Infect. 2009;15:1193-4. (PMID: 19732083) 47. khan FY, Elouzi EB, Asif M. Acute acalculous cholecystitis complicating typhoid fever in an adult patient: a case report and review of the literature. Travel Med Infect Dis. 2009;7:203-6. (PMID: 19717100) 48. Drage M, Reid A, Callaghan CJ, Baber Y, Freeman S, Huguet E, et al. Acute cytomegalovirus cholecystitis following renal transplantation. Am J Transplant. 2009;9:1249-52. (PMID: 19422351) 49. Ohtaki H, Ohkusu K, Sawamura H, Ohta H, Inoue R, Iwasa J, et al. First report of acute cholecystitis with sepsis caused by Cellulomonas denverensis. J Clin Microbiol. 2009;47:3391-3. (PMID: 19656981) 50. Yildirim M, Ozaydin I, Sahin I, Yasar M. Acute calculous cholecystitis caused by Candida lusitaniae: an unusual causative organism in a patient without underlying malignancy. Jpn J Infect Dis. 2008;61:138-9. (PMID: 18362405) PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 20 of 32 Acute Cholecystitis 51. Kune GA, Burdon JG. Are antibiotics necessary in acute cholecystitis? Med J Aust. 1975;2:627-30. (PMID: 1207539) 52. Olsen JC, McGrath NA, Schwarz DG, Cutcliffe BJ, Stern JL. A double-blind randomized clinical trial evaluating the analgesic efficacy of ketorolac versus butorphanol for patients with suspected biliary colic in the emergency department. Acad Emerg Med. 2008;15:718-22. (PMID: 18637080) 53. Helm JF, Venu RP, Geenen JE, Hogan WJ, Dodds WJ, Toouli J, et al. Effects of morphine on the human sphincter of Oddi. Gut. 1988;29:1402-7. (PMID: 3197985) 54. Jarvinen HJ, Hastbacka J. Early cholecystectomy for acute cholecystitis: a prospective randomized study. Ann Surg. 1980;191:501-5. (PMID: 6445180) 55. Navez B, Mutter D, Russier Y, Vix M, Jamali F, Lipski D, et al. Safety of laparoscopic approach for acute cholecystitis: retrospective study of 609 cases. World J Surg. 2001;25:1352-6. (PMID: 11596902) 56. Kiviluoto T, Siren J, Luukkonen P, Kivilaakso E. Randomised trial of laparoscopic versus open cholecystectomy for acute and gangrenous cholecystitis. Lancet. 1998;351:321-5. (PMID: 9652612) 57. Siddiqui T, MacDonald A, Chong PS, Jenkins JT. Early versus delayed laparoscopic cholecystectomy for acute cholecystitis: a meta-analysis of randomized clinical trials. Am J Surg. 2008;195:40-7. (PMID: 18070735) 58. Gurusamy K, Samraj K, Gluud C, Wilson E, Davidson BR. Meta-analysis of randomized controlled trials on the safety and effectiveness of early versus delayed laparoscopic cholecystectomy for acute cholecystitis. Br J Surg. 2010;97:141-50. (PMID: 20035546) 59. Gurusamy KS, Junnarkar S, Farouk M, Davidson BR. Day-case versus overnight stay for laparoscopic cholecystectomy. Cochrane Database Syst Rev. 2008;(3):CD006798. (PMID: 18677781) 60. Briggs CD, Irving GB, Mann CD, Cresswell A, Englert L, Peterson M, et al. Introduction of a day-case laparoscopic cholecystectomy service in the UK: a critical analysis of factors influencing same-day discharge and contact with primary care providers. Ann R Coll Surg Engl. 2009;91:583-90. (PMID: 19558787) 61. Linke GR, Tarantino I, Hoetzel R, Warschkow R, Lange J, Lachat R, et al. Transvaginal rigid-hybrid NOTES cholecystectomy: evaluation in routine clinical practice. Endoscopy. 2010;42:571-5. (PMID: 20432208) 62. Han IW, Jang JY, Kang MJ, Lee KB, Lee SE, Kim SW. Early versus delayed laparoscopic cholecystectomy after percutaneous transhepatic gallbladder drainage. J Hepatobiliary Pancreat Sci. 2012;19:187-93. (PMID: 21938408) 63. Wiseman JT, Sharuk MN, Singla A, Cahan M, Litwin DE, Tseng JF, et al. Surgical management of acute cholecystitis at a tertiary care center in the modern era. Arch Surg. 2010;145:439-44. (PMID: 20479341) 64. Vemulapalli P, Agaba EA, Camacho D. Single incision laparoscopic cholecystectomy: a single center experience. Int J Surg. 2011;9:410-3. (PMID: 21515426) 65. Spira RM, Nissan A, Zamir O, Cohen T, Fields SI, Freund HR. Percutaneous transhepatic cholecystostomy and delayed laparoscopic cholecystectomy in critically ill patients with acute calculus cholecystitis. Am J Surg. 2002;183:62-6. (PMID: 11869705) 66. Sugiyama M, Tokuhara M, Atomi Y. Is percutaneous cholecystostomy the optimal treatment for acute cholecystitis in the very elderly? World J Surg. 1998;22:459-63. (PMID: 9564288) 67. Shirai Y, Tsukada K, Kawaguchi H, Ohtani T, Muto T, Hatakeyama K. Percutaneous transhepatic cholecystostomy for acute acalculous cholecystitis. Br J Surg. 1993;80:1440-2. (PMID: 8252358) 68. Byrne MF, Suhocki P, Mitchell RM, Pappas TN, Stiffler HL, Jowell PS, et al. Percutaneous cholecystostomy in patients with acute cholecystitis: experience of 45 patients at a US referral center. J Am Coll Surg. 2003;197:206-11. (PMID: 12892798) 69. Akyürek N, Salman B, Yüksel O, Tezcaner T, Irkörücü O, Yücel C, Oktar S, Tatlicioglu E. Management of acute calculous cholecystitis in high-risk patients: percutaneous cholecystotomy followed by early laparoscopic cholecystectomy. Surg Laparosc Endosc Percutan Tech. 2005 Dec;15(6):315-20. (PMID: 16340560) 70. Joseph T, Unver K, Hwang GL, Rosenberg J, Sze DY, Hashimi S, et al. Percutaneous cholecystostomy for acute cholecystitis: ten-year experience. J Vasc Interv Radiol. 2012;23:83-8.e1. (PMID: 22133709) 71. Bedirli A, Sakrak O, Sozuer EM, Kerek M, Guler I. Factors effecting the complications in the natural history of acute cholecystitis. Hepatogastroenterology. 2001;48:1275-8. (PMID: 11677945) 72. Johansson M, Thune A, Blomqvist A, Nelvin L, Lundell L. Management of acute cholecystitis in the laparoscopic era: results of a prospective, randomized clinical trial. J Gastrointest Surg. 2003;7:642-5. (PMID: 12850677) 73. Tenconi SM, Boni L, Colombo EM, Dionigi G, Rovera F, Cassinotti E. Laparoscopic cholecystectomy as day-surgery procedure: current indications and patients' selection. Int J Surg. 2008;6 Suppl 1:S86-8. (PMID: 19167938) 74. Cherng N, Witkowski ET, Sneider EB, Wiseman JT, Lewis J, Litwin DE, et al. Use of cholecystostomy tubes in the management of patients with primary diagnosis of acute cholecystitis. J Am Coll Surg. 2012;214:196-201. (PMID: 22192897) PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 21 of 32 Acute Cholecystitis 75. Lo CM, Liu CL, Fan ST, Lai EC, Wong J. Prospective randomized study of early versus delayed laparoscopic cholecystectomy for acute cholecystitis. Ann Surg. 1998;227:461-7. (PMID: 9563529) 76. Lai PB, Kwong KH, Leung KL, Kwok SP, Chan AC, Chung SC, et al. Randomized trial of early versus delayed laparoscopic cholecystectomy for acute cholecystitis. Br J Surg. 1998;85:764-7. (PMID: 9667702) 77. Chang L, Moonka R, Stelzner M. Percutaneous cholecystostomy for acute cholecystitis in veteran patients. Am J Surg. 2000;180:198-202. (PMID: 11084129) 78. Lai EC, Mok FP, Tan ES, Lo CM, Fan ST, You KT, Wong J. Endoscopic biliary drainage for severe acute cholangitis. N Engl J Med. 1992;326:1582-6. (PMID: 1584258) 79. Leung JW, Chung SC, Sung JJ, Banez VP, Li AK. Urgent endoscopic drainage for acute suppurative cholangitis. Lancet. 1989;1:1307-9. (PMID: 2566834) 80. Ke ZW, Zheng CZ, Li JH, Yin K, Hua JD. Prospective evaluation of magnetic resonance cholangiography in patients with suspected common bile duct stones before laparoscopic cholecystectomy. Hepatobiliary Pancreat Dis Int. 2003;2:576-80. (PMID: 14627523) 81. Strasberg SM, Hertl M, Soper NJ. An analysis of the problem of biliary injury during laparoscopic cholecystectomy. J Am Coll Surg. 1995;180:101-25. (PMID: 8000648) 82. Mahatharadol V. Bile duct injuries during laparoscopic cholecystectomy: an audit of 1522 cases. Hepatogastroenterology. 2004;51:12-4. (PMID: 15011821) 83. Werbel GB, Nahrwold DL, Joehl RJ, Vogelzang RL, Rege RV. Percutaneous cholecystostomy in the diagnosis and treatment of acute cholecystitis in the high-risk patient. Arch Surg. 1989;124:782-5. (PMID: 2742479) PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 22 of 32 Acute Cholecystitis Top Glossary ALT alanine aminotransferase AST aspartate aminotransferase CBC complete blood count CDCA chenodeoxycholic acid CI confidence interval CT computed tomography DISIDA diisopropyl phenyl carboxymethyl iminodiacetic acid ERCP endoscopic retrograde cholangiopancreatography GI gastrointestinal HIDA hepato-iminodiacetic acid ICU intensive care unit IgG immunoglobulin G IgM immunoglobulin M iv intravenous LFT liver function test MRC magnetic resonance cholangiography MRCP magnetic resonance cholangiopancreatography NSAID nonsteroidal anti-inflammatory drug RR risk ratio SD standard deviation TPN total parenteral nutrition UDCA ursodeoxycholic acid PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 23 of 32 Acute Cholecystitis PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 24 of 32 Acute Cholecystitis Top Tables Laboratory and Other Studies for Acute Cholecystitis Test Notes Complete blood count Look for leukocytosis Liver function tests Can be elevated in acute cholecystitis Serum bilirubin If >4 mg/dL, consider common bile-duct stones or Mirizzi's syndrome Serum amylase If significant increases (more than three times the upper limit of normal), consider pancreatitis or common bile-duct stones (33) Serum alkaline phosphatase Elevation significantly predicts acute cholecystitis (25) Right upper quadrant ultrasound scan Sensitivity 81-98% Specificity 70-98% Portable, inexpensive. Sonographic Murphy's sign (showing maximal tenderness directly over the visualized gallbladder) is over 90% predictive of acute cholecystitis HIDA scan Sensitivity 85-97% Specificity 90% CT scan Expensive; most useful to diagnose such complications as perforation MRI scan or MRCP scan Sensitivity 100% for cystic-duct obstruction; 69 for gallbladder-wall thickening Specificity 93% for cystic-duct obstruction; 83% for gallbladder-wall thickening Commonly used to diagnose ductal obstruction caused by stones or a malignant lesion CT = computed tomography; HIDA = hepato-iminodiacetic acid; MRCP = magnetic resonance cholangiopancreatography; MRI = magnetic resonance imaging. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 25 of 32 Acute Cholecystitis Differential Diagnosis of Acute Cholecystitis Disease Characteristics Acute cholecystitis Mid-epigastric pain progressing to right upper quadrant. Pain may also radiate to right scapula, right shoulder, back, or lower abdomen. Murphy's sign is highly specific and predictive Bilirubin >4 mg/dL is not a feature of uncomplicated acute cholecystitis Acute cholangitis Charcot triad (right upper quadrant pain, fever, jaundice) or Reynold pentad (Charcot triad and shock and mental-status changes) Bilirubin generally >4 mg/dL. AST and ALT levels may exceed 1000 U/L Acute appendicitis Mid-epigastric pain radiating to right lower quadrant Can mimic acute cholecystitis, especially with a high-lying cecum Acute pancreatitis Mid-epigastric pain radiating to the back, nausea, vomiting, elevated amylase and lipase Vomiting and hyperamylasemia are generally more pronounced than in acute cholecystitis Pyelonephritis (right) Costovertebral angle tenderness, evidence of urinary infection Urinalysis helps establish the diagnosis Peptic ulcer disease Right upper quadrant or mid-epigastric pain Perforated ulcer can mimic acute cholecystitis Pulmonary/pleural disease Cough, shortness of breath, chest or upper abdominal pain Pleuritic pain component much less common in acute cholecystitis Acute viral hepatitis Prodromal syndrome, jaundice, AST and ALT levels generally >1000 U/L LFT and bilirubin level usually much higher than in acute cholecystitis Acute alcoholic hepatitis Right upper quadrant pain, fever, jaundice, coagulopathy, leukocytosis, AST level usually two to three times greater than ALT level Bilirubin level generally >4 mg/dL Recent significant alcohol intake Inferior myocardial infarction Chest/mid-epigastric pain, diaphoresis, shortness of breath, elevated cardiac enzymes, acutely abnormal electrocardiogram Presence of cardiac risk factors. Pain characteristics generally different than acute cholecystitis Mesenteric ischemia Periumbilical or mid-epigastric pain out of proportion to tenderness Fitz-Hugh-Curtis syndrome (gonococcal perihepatitis) Right upper quadrant pain, adnexal tenderness, leukocytosis Cervical smear shows gonococci Hepatic abscess or tumor Right upper quadrant pain, fever Probably requires imaging studies to differentiate Pre- and post-herpetic neuralgia Right upper quadrant pain, fever, and malaise followed by vesicular rash on the thoracic dermatome PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 26 of 32 Acute Cholecystitis Varicella IgM and IgG antibody assays helpful Bleeding or infection of hepatic hydatid cysts Right upper quadrant pain and fever Ultrasound or CT scans confirm the diagnosis (34) Gall bladder ascariasis Right upper quadrant pain and fever Ultrasound or MRC confirms the diagnosis (35) Benign liver adenomas Right upper quadrant pain Ultrasound, CT scans, and biopsy confirm the diagnosis (36) Torsion of the gallbladder Right upper quadrant pain and fever Ultrasound or CT scans confirm the diagnosis (37) Bleeding within the gallbladder Right upper quadrant pain Ultrasound or CT scans confirm the diagnosis (38) ALT = alanine aminotransferase; AST = aspartate aminotransferase; CT = computed tomography; IgG = immunoglobulin G; IgM = immunoglobulin M; LFT = liver function test; MRC = magnetic resonance cholangiography. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 27 of 32 Acute Cholecystitis Drug Treatment for Acute Cholecystitis Drug or Drug Class Dosing Penicillins Piperacillin/tazobactam (Zosyn) 3.375 g iv q6hr Ampicillin/sulbactam (Unasyn) 3 g iv q6hr Ticarcillin/clavulanate (Timentin) 3.1 g iv q6hr Ampicillin 2 g iv q6hr Side Effects Precautions Hypersensitivity reactions, hematologic toxicity, vomiting, diarrhea Seizures can occur when large doses given with renal impairment Constipation, hypokalemia, headache If CrCl<40, decrease dose to 2.25 g iv q6-8hr Clinical Use If CrCl<30, extend dosing interval Nephrotoxicity If <60 kg or CrCl<60, decrease dose. Monitor electrolytes If CrCl<50, extend dosing interval Combine with gentamicin and metronidazole Other antibiotics Ceftazidime (Fortaz, Tazicef) 1 g iv q8hr Hypersensitivity reactions, hematologic toxicity, hepatotoxicity, vomiting, diarrhea If CrCl<50, decrease dose Combine with metronidazole Metronidazole (Flagyl, Metro) 500 mg iv q6hr Vomiting, diarrhea, anorexia, headache, dizziness Carcinogenicity. Avoid with pregnancy. Avoid alcohol. Decrease dose by 50% with severe hepatic disease. Caution with: CKD, warfarin Used in combination therapy Gentamicin 3-5 mg/kg total daily dose, dosed q8hr Vomiting, hepatotoxicity Neurotoxicity, ototoxicity, nephrotoxicity, neuromuscular blockade, respiratory paralysis. Use serum levels to guide dosing. Avoid with pregnancy. Caution with severe hepatic disease. Decrease dose with CKD Used in combination therapy 1 g iv q8hr Vomiting diarrhea, constipation, headache Caution with seizure disorder. If CrCl<50, decrease dose Meropenem (Merrem) = black box warning; bid = twice daily; CKD = chronic kidney disease; CNS = central nervous system; CrCl = creatinine clearance; GI = gastrointestinal; IM = intramuscular; iv = intravenous; PO = oral; q6hr = every 6 hours; qd = once daily; qid = four times daily; SC = subcutaneous; tid = three times daily. PIER provides key prescribing information for practitioners but is not intended to be a source of comprehensive drug information. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 28 of 32 Acute Cholecystitis Top Figures Gallbladder Ultrasound Showing Gallstones On ultrasonography, gallstones appear as an echogenic focus that casts an acoustic shadow. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 29 of 32 Acute Cholecystitis Acalculous Cholecystitis Gallbladder ultrasound consistent with acalculous cholecystitis showing an absence of gallstones or sludge, thickened gallbladder wall, and pericholecystic fluid. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 30 of 32 Acute Cholecystitis Normal Gallbladder Ultrasound An ultrasound of a normal gallbladder. The gallbladder wall is denoted by a thin white line. The gallbladder is filled with fluid and appears black. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 31 of 32 Acute Cholecystitis Gallstone Ileus Plain film of the abdomen showing air in the hepatic biliary tree (arrow) and dilated loops of bowel. Air in the biliary tree and signs of bowel obstruction support the diagnosis of fistula between the biliary tree and bowel, most likely created by a gallstone that obstructed the cystic duct, eroded through the wall, and is now obstructing the small bowel. PIER is copyrighted ©2013 by the American College of Physicians. 190 N. Independence Mall West, Philadelphia, PA 19106, USA. Page 32 of 32