AGA technical review on intestinal ischemia. American Gastrointestinal Association.

This literature review and the recommendations therein were prepared for the American Gastroenterological Association Clinical Practice and Practice Economics Committee. The paper was approved by the committee on September 25, 1999, and by the AGA Governing Board on November 25, 1999.

History of mesenteric ischemia. The evolution of a diagnosis and management.

This article has traced the evolution of our knowledge of mesenteric ischemia from the initial stage of recognition of the condition and its manifestations, through the phase of treatment after the fact-resection of gangrenous intestine, to our present-day attempts to diagnose and treat the ischemic episode before death of the bowel and patient occurs. It is history from the authors' perspective, and because of limitations of space it is, perforce, highly selective. Hundreds of valuable contributions could not be included, and their omission in no way detracts from their importance. A number of surgeons, including Williams and Bergen in this country, Marston in England, Saegesser in Switzerland, and Kieny in France, have made mesenteric ischemia a major focus of their careers and have published extensively on it. The first book devoted to all aspects of mesenteric ischemia, Vascular Disorders of the Intestines edited by Boley, Schwartz, and Williams, was published in 1971. Since that time a number of books and monographs have chronicled progress in the field. Together these references make a good foundation for newly interested investigators in the subject. The results of diagnosis and management of mesenteric ischemia have improved significantly over the past 100 years but remain poor. The best part of the history of mesenteric ischemia remains to be written.

Acute mesenteric ischemia.

The term acute mesenteric ischemia (AMI) is applied to a wide spectrum of bowel injury within the distribution of the superior mesenteric vessels, ranging from reversible alterations in bowel function to transmural necrosis of the bowel wall. Intensivists not only are called upon to manage this catastrophic disease but also may be faced with AMI as a consequence of other illnesses that they treat.

Bloodless splenic surgery: the safe warm-ischemic time.

To assess the feasibility of a technique of bloodless splenic surgery, experiments were performed to determine the safe warm-ischemic time of the spleen. Ten mongrel dogs were divided into two groups. Group I (n = 5) underwent division of all collateral splenic vessels, followed by total splenic artery and vein occlusion for 3 hours. Group II (n = 5) underwent similar collateral devascularization, but with total occlusion of the splenic pedicle for 2 hours. All animals underwent sulfur colloid scintiscanning preoperatively and 2 weeks postoperatively. Blood specimens were analyzed for the presence of Howell-Jolly bodies and immunoglobulin (Ig) G IgG and IgM levels. Pathological examination of the spleens was performed 2 weeks postoperatively. Postoperative scintiscanning showed very poor splenic visualization in two of the five group I dogs. Pathologically these spleens had extensive necrosis. The remaining eight spleens had normal scans, and only mild congestion was noted. Howell-Jolly bodies were found in all group I dogs (mean, 14.6) but in only 2 group II dogs (mean, 0.6). In four group I dogs, a marked decrease in peripheral IgG was noted. Splenic immunoglobulin levels and peripheral IgM were similar in both groups. This study demonstrates that 3 hours of warm splenic ischemia resulted in splenic necrosis and loss of function in 40% of the dogs tested. Two hours of ischemia appears to be safe for dogs; certainly 1 hour should be safe for humans and should allow sufficient time for most splenic surgical procedures.

Digitally assisted laparoscopic drainage of multiple intraabdominal abscesses.

Laparoscopic drainage of multiple walled off intraabdominal abscesses may be difficult to perform safely due to a lack of tactile sensation. A single finger introduced through a small abdominal incision can be used to aid in the dissection and may obviate the need for open laparotomy in some cases. Digitally-assisted laparoscopic exploration and dissection utilizes the superior visualization of laparoscopy without completely sacrificing the benefits of tactile sensation. A case is reported in which this technique was successfully employed to drain multiple intraabdominal abscesses in a young boy.

Laparoscopic cholecystectomy in teenagers.

The positive experience with laparoscopic cholecystectomy (LC) in the adult surgical community encouraged us to perform LC in our last nine adolescent patients requiring cholecystectomy. There were no operative or postoperative complications, and the average hospital stay was less than 3 days. All the teenagers resumed their normal activities 1 week after surgery and were pleased with the small operative scars. Once the technique has been mastered and adequate experience gained with the new instrumentation, laparoscopic cholecystectomy would seem to offer many advantages in the teenage patient.

Acute mesenteric ischemia: an aggressive diagnostic and therapeutic approach. 1991 Roussel Lecture.

The incidence of acute mesenteric ischemia (AMI) has increased substantially over the last few decades. Death rates of 70% to 90% have been reported for traditional methods of diagnosis and therapy. Use of an aggressive radiologic, pharmacologic and surgical approach has decreased the mortality and morbidity associated with AMI. The cornerstones of management are prompt diagnosis by the earlier and more liberal use of angiography and the incorporation of intra-arterial papaverine in the treatment of both occlusive and nonocclusive AMI. Widespread adoption of this protocol in patients at risk might improve the overall results of treatment of AMI.

Anatomy of the splanchnic circulation.

The blood supply to the intestines is a complex one, including branches of the three main splanchnic arteries as well as a vast collateral circulation. The variant anatomy and collateral pathways are described, based on anatomic dissections and angiographic studies, to focus attention on anatomically based explanations for clinical entities.

Aggressive approach to acute mesenteric ischemia.

An aggressive diagnostic and therapeutic approach to acute mesenteric ischemia can dramatically lower the mortality of this lethal disease. The cornerstones of this approach are the earlier and more liberal use of angiography and the use of intra-arterial infusions of vasodilators in the treatment of both nonocclusive and occlusive mesenteric ischemia.

Mesenteric venous thrombosis.

Mesenteric venous occlusion produces a spectrum of clinical presentations, the most common of which is the acute onset of abdominal pain with progressive signs and symptoms of bowel infarction. This acute form of mesenteric venous thrombosis, compared with other forms of acute mesenteric infarction, occurs in younger patients, typically has a more indolent and nonspecific course, involves shorter segments of bowel, and has a lower mortality rate. In contradistinction to our recommended therapy in other forms of acute mesenteric infarction, immediate anticoagulation is indicated for mesenteric venous thrombosis. Second-look operations are used, as in other forms of acute mesenteric infarction, whenever portions of bowel of questionable viability are not resected at the primary operation. Chronic mesenteric venous thrombosis may produce no symptoms or may cause gastrointestinal bleeding from portal hypertension. Newer imaging techniques have increased the ability to diagnose and define the extent of all forms of mesenteric venous thrombosis and have added to the therapeutic options available to manage them.

Colonic ischemia.

Our understanding of ischemia and the importance of this disease in the elderly have increased dramatically over the past 30 years. Moreover, the number of patients found to have colonic ischemia can be expected to increase over the next several decades as that portion of our population older than 65 years grows and the many forms of ischemic injury to the colon are better appreciated. Earlier diagnosis should follow the wider use of colonoscopy, and recognition of the ischemic nature of the varied disease manifestations and identification of patients at high risk for this disease should result in better management.

Colonic ischemia complicating immunotherapy with interleukin-2 and interferon-alpha.

Colonic ischemia (CI) is a rare complication of high-dose interleukin-2 (IL-2) immunotherapy. This complication occurred in three of 141 patients (2.1%) with metastatic cancer treated with high-dose IL-2 therapy; CI only developed in patients receiving interferon-alpha (IFN) with IL-2 (three of 21, 14%) compared with none of 120 in those patients receiving IL-2 alone (P equals 0.0009). Severe diarrhea (greater than or equal to 7 bowel movements/day) also was significantly more common in patients receiving IFN with IL-2 (six of 21, 29%) than in those receiving IL-2 alone (three of 120, 2.5%, P equals 0.001) and preceded the clinical diagnosis of CI in all three patients. Three of nine patients with severe diarrhea had CI. Hematochezia occurred in four patients, all of whom received IFN with IL-2; three had CI, and the other patient had nonspecific colitis. Differences in vasopressor use did not explain the increased risk of CI in patients receiving IFN; those receiving IFN with IL-2 required phenylephrine less often than patients receiving IL-2 alone (P equals 0.01). The administration of lymphokine-activated killer (LAK) cells had no significant effect on the incidence of CI, severe diarrhea, peritonitis, or vasopressor use; two of three patients with CI, however, had their ischemic episode within 24 hours after the last of three LAK cell infusions. In conclusion, CI is an unusual complication of high-dose IL-2 and IFN immunotherapy. In patients receiving such combination therapy, severe diarrhea is a risk factor for the subsequent occurrence of CI.

The irreducible ovary: a true emergency.

The management of a child with an irreducible ovary remains inconsistent in pediatric surgical centers. An informal survey of senior pediatric surgeons and an extensive review of the literature showed a prevailing view that the trapped ovary is not at significant risk of vascular compromise. Two recent cases prompted a review of our experience from 1984 to 1989, during which 1,699 children with inguinal hernias underwent operation, 386 (23%) of whom were girls. Fifteen girls (4%) had irreducible ovaries present at the time of operation and in 4 of the 15 (27%) the ovary was twisted and infarcted. Two of the 4 girls were known to have an irreducible ovary prior to the day of operation--1 was noted 2 months earlier and 1 was noted 1 month earlier. At the time of the initial diagnosis, neither patient had physical findings of vascular compromise of the ovary. In the other two girls, evidence of an infarcted ovary was present when the hernia was first diagnosed and an emergency operation was performed. A 27% incidence of torsion and strangulation of irreducible ovaries appears to be high, but reports of strangulated ovaries have been reported in 2% to 33% of other series. The normal anatomy is altered when an ovary is trapped in a hernia sac, and these changes make torsion more likely. Although an irreducible ovary is not at great risk of compression of its blood supply, this report identifies a significant risk of torsion. This risk warrants treating the asymptomatic irreducible ovary as any other incarcerated hernia--as a true emergency.

A new provocative test for chronic mesenteric ischemia.

A new provocative test for chronic mesenteric ischemia is described, based upon the demonstration of a fall in the intramural pH of the small bowel after introduction of a test meal into the stomach. Intramural pH (pHI) is determined indirectly by tonometry, utilizing a tonometer passed per os. Postoperative assessment of revascularization procedures is also possible by the same technique. Application of the test in an 84-yr-old woman showed good correlation between a preoperative fall in jejunal intramural pH and abdominal pain, and the absence of a fall postoperatively after successful revascularization.

Ischemic diseases of the bowel.

The ischemic bowel diseases are a heterogeneous group of disorders usually seen in elderly individuals. They represent ischemic damage to different portions of the bowel and therefore produce a variety of clinical syndromes and outcomes. Proper diagnosis and management of patients with ischemic bowel disease require vigilance on the part of the physician and a willingness to embark on an aggressive plan of diagnosis and management in the appropriate setting.