Download Gastrointestinal Surgery: Review Questions

Self-Assessment in General Surgery
Gastrointestinal Surgery: Review Questions
Sheilendra S. Mehta, MD
Bhupesh Vasisht, MD
Robert Silich, MD
QUESTIONS
Choose the single best answer for each question.
Questions 1 and 2 refer to the following case study.
A 68-year-old African American man presents to his
primary care physician for a routine physical examination. The patient’s medical history is significant for
hypertension. The patient is found to have guaiacpositive stools and is subsequently referred for colonoscopy. Colonoscopy reveals a “golf ball”- size, nearobstructing tumor in the ascending colon. The biopsy
is positive for adenocarcinoma of the colon.
1.
Which of the following is the next step in the management of this patient?
A) Metastatic workup, including abdominal computed tomography (CT) scan, chest radiograph, and liver profile, followed by colon
resection
B) A course of radiation therapy prior to any
resection
C) Surgical resection in conjunction with chemotherapy
D) Exploratory laparotomy with colon resection
E) Laparoscopic colon resection
2.
After the appropriate evaluation, the patient undergoes surgery. No intraoperative evidence of metastases is identified. Postoperatively, the pathology
report reveals that the tumor is an adenocarcinoma
invading into the pericolonic fat, with 2 involved
lymph nodes. After the patient recovers from
surgery, which of the following is the most appropriate next step in his management?
A) Abdominal CT scan every 6 months
B) No further therapy is indicated, because the
involved nodes were removed
C) Chemotherapy with 5-fluorouracil (5-FU) and
levamisole
D) Measurement of carcinoembryonic antigen
(CEA) levels yearly
E) Colonoscopy every 6 months
3.
A 59-year-old woman with no significant past medical history presents to the emergency department
with a 2-day history of left lower quadrant abdominal pain. The patient denies nausea and vomiting,
although she claims decreased oral intake. She
also reports a low-grade fever and profuse diarrhea. She describes a milder episode several years
ago, which resolved on its own. On physical examination, the patient is found to have left lower
quadrant tenderness with some mild guarding, but
no rebound. She is hemodynamically stable, and
her heart rate is 82 bpm. In the initial management
of this patient, which of the following is the most
sensitive diagnostic test?
A) Complete blood count, SMA-7 (sodium,
potassium, CO2, chloride, glucose, blood urea
nitrogen, and creatinine)
B) An obstructive series
C) A barium enema study
D) Abdominal/pelvic CT with oral contrast
E) Abdominal ultrasound
(turn page for answers)
Dr. Mehta is a Resident in Surgery, Dr. Vasisht is a Chief Resident in
Surgery, and Dr. Silich is Director, Surgical Oncology, Staten Island
University Hospital, Staten Island, NY.
Hospital Physician August 2000
55
Self-Assessment in General Surgery : pp. 55–56
EXPLANATION OF ANSWERS
1. (D) Exploratory laparotomy with colon resection.
The patient should be scheduled for colon resection. The goals of surgical excision of colon cancer
are to both cure the disease and alleviate symptoms.
Even if there is metastatic disease at the time of
surgery, it is important to remove the primary
tumor to prevent complications (eg, obstruction,
bleeding). Therefore, a metastatic workup with CT
or liver function testing to preoperatively stage the
patient is typically not warranted. It is more important to rule out a synchronous lesion via colonoscopy. Patients with stage III cancer can be treated
with chemotherapy—eg, 5-FU and levamisole.
Patients with stage I and low-risk stage II cancers do
not need additional therapy. Radiation therapy is
ineffective as adjuvant therapy for patients with
colon cancer; radiation therapy is only beneficial in
patients with rectal cancer.
Using laparoscopic operative techniques in the
treatment of cancer has raised considerable concern. A laparoscopic colectomy could compromise
cancer control by several mechanisms, including
inadequate lymphadenectomy, inadequate intraoperative staging, and seeding of tumor at port or
specimen extraction sites. Currently, a national prospective randomized trial is in progress to determine the role of laparoscopy in cancer surgery.
Until then, laparoscopic colon resection for cancer
should be reserved for use in a research setting.
2. (C) Chemotherapy with 5-FU and levamisole. The
lesion described by the pathology report is a T3 N1
M0 lesion—ie, extending beyond the muscularis
propria and into the pericolonic fat within the
sleeves of the mesentery, and 1 to 3 positive nodes.
This is a stage III tumor.
About 25% of patients with stage II tumors and
50% of patients with stage III tumors eventually die
from growth of micrometastatic disease that was
present at the time of primary tumor resection.
Several randomized, prospective studies have demonstrated that postoperative, adjuvant, systemic
chemotherapy benefits certain subgroups of patients. Patients with stage III disease had improved
disease-free and overall survival rates if treated with
the combination of 5-FU and levamisole.1
Fifty percent of colon cancers that recur do so
within 2 years of surgery, and 90% of the recurrences
are evident by 3 years.2 Therefore, routine follow-up
after a potentially curative operation should include
history and physical examination, measurement of
CEA levels, and fecal occult blood testing every
6 months for 3 years, then yearly. Liver function tests,
abdominal CT scan, colonoscopy, and chest radiograph should also be performed yearly.
3. (D) Abdominal/pelvic CT with oral contrast. A CT
scan with oral contrast is the test of choice. If this is
equivocal or suggestive of other pathology, one should
next consider obtaining a Gastrografin enema.
Although a leukocyte count may help demonstrate an infectious etiology, it is a relatively nonspecific test. A normal leukocyte count does not exclude
an infectious process, and it is common for patients
to have an increased leukocyte count because of factors such as dehydration or simply stress. The SMA-7
electrolytes are also nonspecific and usually represent the end result of the disease process; they are of
limited benefit in determining the diagnosis of this
patient’s abdominal symptoms.
Abdominal films are most helpful for patients
suspected of perforation or intestinal obstruction
and for patients in whom the diagnosis is uncertain.
This study may demonstrate free air, which would
suggest an intestinal perforation.
The use of ultrasound is limited in this situation.
It is the test of choice in patients suspected of having gallbladder pathology. The kidneys, liver, and
pancreas may also be evaluated with ultrasound;
however, intestinal pathology is not well visualized
with ultrasound.
This patient most likely has an episode of acute
diverticulitis. Because of the risk for perforation or
peritonitis, barium enemas and sigmoidoscopy are
usually reserved for patients who have recovered
from an attack of acute diverticulitis.
Other considerations in the differential diagnosis
should include irritable bowel syndrome, appendicitis, inflammatory bowel disease, and pyelonephritis.
All these diagnoses will be better delineated with
the use of CT scan.
REFERENCES
1. Moertel CG, Fleming TR, Macdonald JS, et al: Levamisole
and fluorouracil for adjuvant therapy of resected colon
carcinoma. N Engl J Med 1990;322:352–358.
2. Shelton AA, Wong WD: Colorectal cancer. In Current
Surgical Therapy, 6th ed. Cameron JL, ed. St. Louis:
Mosby, 1998:226–227.
Copyright 2000 by Turner White Communications Inc., Wayne, PA. All rights reserved.
56 Hospital Physician August 2000