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Meckel’s diverticulum: Review and surgical management
CURRENT REVIEWS IN GASTROINTESTINAL, MINIMALLY INVASIVE, AND ENDOCRINE SURGERY
Meckel’s Diverticulum: Review and Surgical Management Kim G. Mendelson, MD, B. Marcus Bailey, MD, Tara D. Balint, MD, and Walter E. Pofahl, MD Department of General Surgery, Brody School of Medicine, East Carolina University, Greenville, North Carolina INTRODUCTION Meckel’s diverticulum is the most common congenital anomaly of the small intestine, with an estimated incidence in the general population of approximately 2%.1 This true diverticulum, which contains all layers of the intestinal wall, is a result of the failed obliteration of the omphalomesenteric duct. Occurring in the terminal ileum, it is generally discovered as an incidental finding during laparotomy. The management of the asymptomatic diverticulum is controversial. When symptomatic, Meckel’s diverticulum can present with obstruction, inflammation, or hemorrhage, requiring surgical treatment. Embryology and Anatomy The omphalomesenteric, or vitelline, duct serves to form a communication between the yolk sac and the intestine. The obliteration of this duct normally occurs during the fifth week of embryologic development. If failure of obliteration of the proximal duct occurs, a Meckel’s diverticulum results. Continued patency of the entire duct results in a fistula from the intestine to the umbilicus.2 Meckel’s diverticula commonly are found in the distal 90 cm of the ileum, on the antimesenteric border. These are true diverticula, containing all normal layers of the intestinal wall. They sometimes contain ectopic mucosa, most often gastric,3 but occasionally pancreatic, colonic, or duodenal.2,4 Its blood supply comes from a remnant of the vitelline artery, generally a terminal branch of the superior mesenteric artery.2 Epidemiology In most series, Meckel’s diverticula are more common in men, with a male-to-female ratio of up to 4:1.3 In addition, some studies have reported that men tend to have more symptomatic diverticula, with a male-to-female ratio of around 2.8:1.1,2,4 An increased incidence of Meckel’s diverticula has been seen Correspondence: Inquiries to Kim G. Mendelson, MD, Department of General Surgery, Brody School of Medicine, East Carolina University, PCMH-TA 301-A, 2100 Stantonsburg Rd., Greenville, NC 27834; fax: (252) 816-3156; e-mail: mendelsonk@ mail.ecu.edu
in newborns with gastrointestinal congenital defects such as gastrointestinal atresia, in which 1 series found a 26% incidence.5 Some suggestion has been made that the incidence is increased in medical conditions such as Crohn’s disease, although a strong association has not been found.4 Clinical Presentation Meckel originally estimated the complication risk of the diverticulum to be 25%. This figure is now felt to be too high, and more recent reviews indicate that symptomatic diverticula occur in between 4.2% and 16.9% of individuals with Meckel’s diverticula. Painless gastrointestinal bleeding is more common as an initial presentation in children, whereas painful inflammation or obstruction is more common in adults.4 The most common cause of symptomatic Meckel’s diverticula is obstruction. This results from intussusception, inflammation, omphalomesenteric bands, adhesions, or adenocarcinoma, and it accounts for 26.2% to 53.4% of complications.4 In addition, Meckel’s diverticula can be involved in a hernia sac, referred to as a Littre’s hernia. These hernias are predominantly inguinal, and they can become incarcerated and strangulated. In Mackey’s series, out of 8 patients who presented with symptoms related to Littre’s hernia, 7 had an incarcerated hernia and 1 was strangulated.2 The second most common presentation of symptomatic Meckel’s diverticula is diverticulitis, which occurs in 12.7% to 30.9% of cases.4 These patients often present with signs and symptoms identical to those of acute appendicitis, and diagnosis is confirmed during surgical exploration. In up to 20% of these cases, the diverticulum will perforate from infarction, ulcer, or foreign body. Cases have also been reported of fistula formation between an inflamed Meckel’s diverticulum and the adjacent intestine.2 Gastrointestinal hemorrhage is another common presentation, occurring in 10.9% to 38.9% of cases. This is especially common in men and in children, who present mainly before the age of 20 years. The degree of bleeding ranges from occult blood loss to frank bright red blood from the rectum with associated shock. Commonly, these patients have a history of recurrent gastrointestinal bleeding.4
CURRENT SURGERY • © 2001 by the Association of Program Directors in Surgery Published by Elsevier Science Inc.
0149-7944/01/$20.00 PII S0149-7944(01)00443-3
455
A less common presentation is malignancy developing in a Meckel’s diverticulum. This occurs in only 0.5% to 4.9% of cases. The most common variety is sarcoma, with carcinoids and adenocarcinoma being the other common types.4 These can either be found incidentally or can present symptomatically with obstruction. Diagnosis Accurate preoperative diagnosis is seldom made. The differential diagnosis of patients presenting with the most common symptoms of complicated Meckel’s diverticula is extensive. Only in the case of lower gastrointestinal bleeding in the pediatric age group are complicated Meckel’s diverticula near the top of the list. In adult patients with obstruction, lower abdominal pain or gastrointestinal bleeding, the correct diagnosis is not commonly made before operation.4 Isotope scanning has been used to detect the presence of a Meckel’s diverticulum containing ectopic gastric mucosa. In this test, technetium pertechnate is injected intravenously, where it is taken up by gastric mucosal cells, excreted, and visualized. An area of 1.8 cm2 is required to obtain a positive result. The sensitivity and specificity in adults is only 62.5% and 9%, respectively, although in children an accuracy of 90% exists. In order to increase the accuracy of an isotope scan, pentagastrin, cimetidine, or glucagon can be administered. Pentagastrin acts to increase isotope uptake by mucosal cells, whereas cimetidine inhibits intraluminal release and glucagon decreases peristalsis. False-positive results of isotope scanning can be caused by intussusception, volvulus, small bowel obstruction, acute appendicitis, ileal carcinoid, intestinal arteriovenous malformation, and colitis. An impaired vascular supply or rapid hemorrhage can result in false-negative results, either because the isotope cannot reach the area of interest or from washout.4,6 For these reasons, even with thorough physical examination and roentgenologic testing, most symptomatic patients proceed to surgery before definitive diagnosis. In the series by Mackey and Dineen,2 isotope scanning only identified half of the patients with hemorrhage from Meckel’s diverticula containing ectopic gastric mucosa. Other studies used for diagnosis were also not helpful. Arteriography only was successful in localizing bleeding in 2 out of 6 of patients, barium enema was only helpful in 1 patient who had intussusception, and small bowel series was only diagnostic in 5 out of 17 patients.2 Surgical Treatment Symptomatic Meckel’s diverticula should be removed surgically. In addition, pathologic diverticula found on laparotomy should also be removed.4,6 Surgical resection has consisted of either simple diverticulectomy or bowel resection, depending on the clinical situation. It has been suggested that the operation of choice is an ileal resection rather than a simple excision, because of the possibility of ectopic tissue extending beyond the diverticulum.4 This tissue, most commonly gastric mucosa, 456
cannot reliably be detected intraoperatively, although a mass may be palpated.1 Certainly, if the diverticulum is associated with hemorrhage from an adjacent ulcer, or if it is broad based, a bowel resection is indicated. However, most feel that simple diverticulectomy can be performed if the entire diverticulum with its blood supply is able to be resected.6 Historically, removal of symptomatic diverticula is associated with a 5% to 10% mortality rate,6 although recent series have reported lower rates.7 The management of incidentally discovered asymptomatic diverticula is more controversial. Soltero and Bill8 in their landmark article assumed a 9% morbidity rate from diverticulectomy, and they argued that because the estimated lifetime risk of developing symptoms from a Meckel’s diverticula is 4.2%, these should be left in place.8 Researchers such as Leijonmarck et al report no complications of incidental diverticula left in situ over a follow-up of 7.8 years.1 Therefore, some feel that they should not be removed, or perhaps only removed in younger patients. However, the complications attributable to incidental diverticulectomy were only 1.2% in Mackey’s series,2 and more recent reports indicate an equally low morbidity and mortality.3,9 A recent series estimated lifetime risk at 6.4% and morbidity from diverticulectomy at 2%. These authors found that an age-related increase in complications did not occur, but more complications in younger patients did occur. They argue that most asymptomatic diverticula should be removed.9 Longterm complications of incidental diverticulectomy, mainly caused by adhesions, is around 2%, whereas for symptomatic diverticulectomy, it is 7%. Especially with newer operative approaches, such as stapling devices and laparoscopy, a more liberal approach to incidental diverticulectomy may be taken.3,4 In addition, symptomatic Meckel’s diverticula may be associated with significant morbidity and mortality. Several series have examined the characteristics of symptomatic vs asymptomatic diverticula. As mentioned earlier, several studies have found a predominance of symptomatic diverticula in men,1,2,4,9,10 although 1 study found an equal incidence.3 Length and width of the diverticulum are also felt to be determinant in symptomatology. Mackey et al found that symptomatic diverticula were more likely to be 2 cm or greater in length.2 Similarly, Leijonmarck et al reported a statistically significant increase in symptomatic diverticula in those longer than 4 cm.1 It had been felt that broad-based diverticula were less likely to be symptomatic because of a lower risk of obstruction. However, Mackey et al did not find any correlation between width and symptomatology,2 whereas Leijonmarck et al found that broad-based diverticula (ⱖ 2 cm) were actually more likely to be symptomatic.1 In addition, Meckel’s diverticula containing ectopic mucosa are more likely to be symptomatic,1-3 whereas the incidence of ectopic tissue in Meckel’s diverticula is between 6% and 40%; up to 80% of symptomatic diverticula contain ectopic tissue.4 For these reasons, indications for resection of asymptomatic diverticula include length greater than 2 cm, younger patients (especially men), and ectopic tissue.6 One dif-
CURRENT SURGERY • Volume 58/Number 5 • September/October 2001
ficulty with this is that ectopic tissue is generally confirmed only at pathologic examination. In summary, although it is generally agreed that symptomatic Meckel’s diverticula should be resected, no clear consensus on the management of asymptomatic diverticula exists. Considering the low complication rates associated with modern diverticulectomy, some authors advocate resection of diverticula in all patients regardless of age or pathology.3,9 Others recommend resection of incidentally discovered diverticula, which exhibit certain high-risk characteristics,2,4 whereas others recommend leaving them in situ.1
CONCLUSION The surgical management of Meckel’s diverticulum continues to be controversial. Although it is generally accepted that symptomatic diverticula should be removed, either by diverticulectomy or by ileal resection, asymptomatic diverticula discovered incidentally at laparotomy or laparoscopy remain a subject of debate. Most authors agree that incidentally discovered diverticula should be removed if this can be accomplished with low morbidity. Newer techniques such as laparoscopy and stapling devices should make this possible.
REFERENCES
Meckel’s diverticulum. Surg Gynecol Obstet. 1983;156:5664. 3. Matsagas MI, Fatouros M, Koulouras B, Giannoukas AD.
Incidence, complications, and management of Meckel’s diverticulum. Arch Surg. 1995;130:143-146. 4. DiGiacomo JC, Cottone FJ. Surgical treatment of Meck-
el’s diverticulum. South Med J. 1993;86:671-675. 5. Simms MH, Corkery JJ. Meckel’s diverticulum: its asso-
ciation with congenital malformation and the significance of atypical morphology. Br J Surg. 1980;67:216-219. 6. Clary BM, Lyerly HK. Meckel’s diverticulum. In:
Sabiston DC, editors. Textbook of Surgery; the Biological Basis of Modern Surgical Practice, 15th ed. Philadelphia: W. B. Saunders, 1997. 7. Wolff BG. Current status of incidental surgery. Dis Colon
Rectum. 1995;38:435-441. 8. Soltero MJ, Bill AH. The natural history of Meckel’s di-
verticulum and its relation to incidental removal: a study of 202 cases of diseased Meckel’s diverticulum found in King County, Washington, over a fifteen year period. Am J Surg. 1976;132:168-173. 9. Cullen JJ, Kelly KA, Moir CR, Hodge DO, Zinsmeister
AR, Melton J. Surgical management of Meckel’s diverticulum. Ann Surg. 1994;220:564-569.
1. Leijonmarck CE, Bonman-Sandelin K, Frisell J, Raf L.
Meckel’s diverticulum in the adult. Br J Surg. 1986;73: 146-149.
10. Bemelman WA, Hugenholtz E, Heij HA, Weisman PH,
2. Mackey WC, Dineen P. A fifty year experience with
CURRENT SURGERY • Volume 58/Number 5 • September/October 2001
Obertop H. Meckel’s diverticulum in Amsterdam: experience in 136 patients. World J Surg. 1995;19:734-737.
457
Meckel’s Diverticulum: Review and Surgical Management Kim G. Mendelson, MD, B. Marcus Bailey, MD, Tara D. Balint, MD, and Walter E. Pofahl, MD Department of General Surgery, Brody School of Medicine, East Carolina University, Greenville, North Carolina INTRODUCTION Meckel’s diverticulum is the most common congenital anomaly of the small intestine, with an estimated incidence in the general population of approximately 2%.1 This true diverticulum, which contains all layers of the intestinal wall, is a result of the failed obliteration of the omphalomesenteric duct. Occurring in the terminal ileum, it is generally discovered as an incidental finding during laparotomy. The management of the asymptomatic diverticulum is controversial. When symptomatic, Meckel’s diverticulum can present with obstruction, inflammation, or hemorrhage, requiring surgical treatment. Embryology and Anatomy The omphalomesenteric, or vitelline, duct serves to form a communication between the yolk sac and the intestine. The obliteration of this duct normally occurs during the fifth week of embryologic development. If failure of obliteration of the proximal duct occurs, a Meckel’s diverticulum results. Continued patency of the entire duct results in a fistula from the intestine to the umbilicus.2 Meckel’s diverticula commonly are found in the distal 90 cm of the ileum, on the antimesenteric border. These are true diverticula, containing all normal layers of the intestinal wall. They sometimes contain ectopic mucosa, most often gastric,3 but occasionally pancreatic, colonic, or duodenal.2,4 Its blood supply comes from a remnant of the vitelline artery, generally a terminal branch of the superior mesenteric artery.2 Epidemiology In most series, Meckel’s diverticula are more common in men, with a male-to-female ratio of up to 4:1.3 In addition, some studies have reported that men tend to have more symptomatic diverticula, with a male-to-female ratio of around 2.8:1.1,2,4 An increased incidence of Meckel’s diverticula has been seen Correspondence: Inquiries to Kim G. Mendelson, MD, Department of General Surgery, Brody School of Medicine, East Carolina University, PCMH-TA 301-A, 2100 Stantonsburg Rd., Greenville, NC 27834; fax: (252) 816-3156; e-mail: mendelsonk@ mail.ecu.edu
in newborns with gastrointestinal congenital defects such as gastrointestinal atresia, in which 1 series found a 26% incidence.5 Some suggestion has been made that the incidence is increased in medical conditions such as Crohn’s disease, although a strong association has not been found.4 Clinical Presentation Meckel originally estimated the complication risk of the diverticulum to be 25%. This figure is now felt to be too high, and more recent reviews indicate that symptomatic diverticula occur in between 4.2% and 16.9% of individuals with Meckel’s diverticula. Painless gastrointestinal bleeding is more common as an initial presentation in children, whereas painful inflammation or obstruction is more common in adults.4 The most common cause of symptomatic Meckel’s diverticula is obstruction. This results from intussusception, inflammation, omphalomesenteric bands, adhesions, or adenocarcinoma, and it accounts for 26.2% to 53.4% of complications.4 In addition, Meckel’s diverticula can be involved in a hernia sac, referred to as a Littre’s hernia. These hernias are predominantly inguinal, and they can become incarcerated and strangulated. In Mackey’s series, out of 8 patients who presented with symptoms related to Littre’s hernia, 7 had an incarcerated hernia and 1 was strangulated.2 The second most common presentation of symptomatic Meckel’s diverticula is diverticulitis, which occurs in 12.7% to 30.9% of cases.4 These patients often present with signs and symptoms identical to those of acute appendicitis, and diagnosis is confirmed during surgical exploration. In up to 20% of these cases, the diverticulum will perforate from infarction, ulcer, or foreign body. Cases have also been reported of fistula formation between an inflamed Meckel’s diverticulum and the adjacent intestine.2 Gastrointestinal hemorrhage is another common presentation, occurring in 10.9% to 38.9% of cases. This is especially common in men and in children, who present mainly before the age of 20 years. The degree of bleeding ranges from occult blood loss to frank bright red blood from the rectum with associated shock. Commonly, these patients have a history of recurrent gastrointestinal bleeding.4
CURRENT SURGERY • © 2001 by the Association of Program Directors in Surgery Published by Elsevier Science Inc.
0149-7944/01/$20.00 PII S0149-7944(01)00443-3
455
A less common presentation is malignancy developing in a Meckel’s diverticulum. This occurs in only 0.5% to 4.9% of cases. The most common variety is sarcoma, with carcinoids and adenocarcinoma being the other common types.4 These can either be found incidentally or can present symptomatically with obstruction. Diagnosis Accurate preoperative diagnosis is seldom made. The differential diagnosis of patients presenting with the most common symptoms of complicated Meckel’s diverticula is extensive. Only in the case of lower gastrointestinal bleeding in the pediatric age group are complicated Meckel’s diverticula near the top of the list. In adult patients with obstruction, lower abdominal pain or gastrointestinal bleeding, the correct diagnosis is not commonly made before operation.4 Isotope scanning has been used to detect the presence of a Meckel’s diverticulum containing ectopic gastric mucosa. In this test, technetium pertechnate is injected intravenously, where it is taken up by gastric mucosal cells, excreted, and visualized. An area of 1.8 cm2 is required to obtain a positive result. The sensitivity and specificity in adults is only 62.5% and 9%, respectively, although in children an accuracy of 90% exists. In order to increase the accuracy of an isotope scan, pentagastrin, cimetidine, or glucagon can be administered. Pentagastrin acts to increase isotope uptake by mucosal cells, whereas cimetidine inhibits intraluminal release and glucagon decreases peristalsis. False-positive results of isotope scanning can be caused by intussusception, volvulus, small bowel obstruction, acute appendicitis, ileal carcinoid, intestinal arteriovenous malformation, and colitis. An impaired vascular supply or rapid hemorrhage can result in false-negative results, either because the isotope cannot reach the area of interest or from washout.4,6 For these reasons, even with thorough physical examination and roentgenologic testing, most symptomatic patients proceed to surgery before definitive diagnosis. In the series by Mackey and Dineen,2 isotope scanning only identified half of the patients with hemorrhage from Meckel’s diverticula containing ectopic gastric mucosa. Other studies used for diagnosis were also not helpful. Arteriography only was successful in localizing bleeding in 2 out of 6 of patients, barium enema was only helpful in 1 patient who had intussusception, and small bowel series was only diagnostic in 5 out of 17 patients.2 Surgical Treatment Symptomatic Meckel’s diverticula should be removed surgically. In addition, pathologic diverticula found on laparotomy should also be removed.4,6 Surgical resection has consisted of either simple diverticulectomy or bowel resection, depending on the clinical situation. It has been suggested that the operation of choice is an ileal resection rather than a simple excision, because of the possibility of ectopic tissue extending beyond the diverticulum.4 This tissue, most commonly gastric mucosa, 456
cannot reliably be detected intraoperatively, although a mass may be palpated.1 Certainly, if the diverticulum is associated with hemorrhage from an adjacent ulcer, or if it is broad based, a bowel resection is indicated. However, most feel that simple diverticulectomy can be performed if the entire diverticulum with its blood supply is able to be resected.6 Historically, removal of symptomatic diverticula is associated with a 5% to 10% mortality rate,6 although recent series have reported lower rates.7 The management of incidentally discovered asymptomatic diverticula is more controversial. Soltero and Bill8 in their landmark article assumed a 9% morbidity rate from diverticulectomy, and they argued that because the estimated lifetime risk of developing symptoms from a Meckel’s diverticula is 4.2%, these should be left in place.8 Researchers such as Leijonmarck et al report no complications of incidental diverticula left in situ over a follow-up of 7.8 years.1 Therefore, some feel that they should not be removed, or perhaps only removed in younger patients. However, the complications attributable to incidental diverticulectomy were only 1.2% in Mackey’s series,2 and more recent reports indicate an equally low morbidity and mortality.3,9 A recent series estimated lifetime risk at 6.4% and morbidity from diverticulectomy at 2%. These authors found that an age-related increase in complications did not occur, but more complications in younger patients did occur. They argue that most asymptomatic diverticula should be removed.9 Longterm complications of incidental diverticulectomy, mainly caused by adhesions, is around 2%, whereas for symptomatic diverticulectomy, it is 7%. Especially with newer operative approaches, such as stapling devices and laparoscopy, a more liberal approach to incidental diverticulectomy may be taken.3,4 In addition, symptomatic Meckel’s diverticula may be associated with significant morbidity and mortality. Several series have examined the characteristics of symptomatic vs asymptomatic diverticula. As mentioned earlier, several studies have found a predominance of symptomatic diverticula in men,1,2,4,9,10 although 1 study found an equal incidence.3 Length and width of the diverticulum are also felt to be determinant in symptomatology. Mackey et al found that symptomatic diverticula were more likely to be 2 cm or greater in length.2 Similarly, Leijonmarck et al reported a statistically significant increase in symptomatic diverticula in those longer than 4 cm.1 It had been felt that broad-based diverticula were less likely to be symptomatic because of a lower risk of obstruction. However, Mackey et al did not find any correlation between width and symptomatology,2 whereas Leijonmarck et al found that broad-based diverticula (ⱖ 2 cm) were actually more likely to be symptomatic.1 In addition, Meckel’s diverticula containing ectopic mucosa are more likely to be symptomatic,1-3 whereas the incidence of ectopic tissue in Meckel’s diverticula is between 6% and 40%; up to 80% of symptomatic diverticula contain ectopic tissue.4 For these reasons, indications for resection of asymptomatic diverticula include length greater than 2 cm, younger patients (especially men), and ectopic tissue.6 One dif-
CURRENT SURGERY • Volume 58/Number 5 • September/October 2001
ficulty with this is that ectopic tissue is generally confirmed only at pathologic examination. In summary, although it is generally agreed that symptomatic Meckel’s diverticula should be resected, no clear consensus on the management of asymptomatic diverticula exists. Considering the low complication rates associated with modern diverticulectomy, some authors advocate resection of diverticula in all patients regardless of age or pathology.3,9 Others recommend resection of incidentally discovered diverticula, which exhibit certain high-risk characteristics,2,4 whereas others recommend leaving them in situ.1
CONCLUSION The surgical management of Meckel’s diverticulum continues to be controversial. Although it is generally accepted that symptomatic diverticula should be removed, either by diverticulectomy or by ileal resection, asymptomatic diverticula discovered incidentally at laparotomy or laparoscopy remain a subject of debate. Most authors agree that incidentally discovered diverticula should be removed if this can be accomplished with low morbidity. Newer techniques such as laparoscopy and stapling devices should make this possible.
REFERENCES
Meckel’s diverticulum. Surg Gynecol Obstet. 1983;156:5664. 3. Matsagas MI, Fatouros M, Koulouras B, Giannoukas AD.
Incidence, complications, and management of Meckel’s diverticulum. Arch Surg. 1995;130:143-146. 4. DiGiacomo JC, Cottone FJ. Surgical treatment of Meck-
el’s diverticulum. South Med J. 1993;86:671-675. 5. Simms MH, Corkery JJ. Meckel’s diverticulum: its asso-
ciation with congenital malformation and the significance of atypical morphology. Br J Surg. 1980;67:216-219. 6. Clary BM, Lyerly HK. Meckel’s diverticulum. In:
Sabiston DC, editors. Textbook of Surgery; the Biological Basis of Modern Surgical Practice, 15th ed. Philadelphia: W. B. Saunders, 1997. 7. Wolff BG. Current status of incidental surgery. Dis Colon
Rectum. 1995;38:435-441. 8. Soltero MJ, Bill AH. The natural history of Meckel’s di-
verticulum and its relation to incidental removal: a study of 202 cases of diseased Meckel’s diverticulum found in King County, Washington, over a fifteen year period. Am J Surg. 1976;132:168-173. 9. Cullen JJ, Kelly KA, Moir CR, Hodge DO, Zinsmeister
AR, Melton J. Surgical management of Meckel’s diverticulum. Ann Surg. 1994;220:564-569.
1. Leijonmarck CE, Bonman-Sandelin K, Frisell J, Raf L.
Meckel’s diverticulum in the adult. Br J Surg. 1986;73: 146-149.
10. Bemelman WA, Hugenholtz E, Heij HA, Weisman PH,
2. Mackey WC, Dineen P. A fifty year experience with
CURRENT SURGERY • Volume 58/Number 5 • September/October 2001
Obertop H. Meckel’s diverticulum in Amsterdam: experience in 136 patients. World J Surg. 1995;19:734-737.
457