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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