Intestinal ischemia: current treatment concepts

Purpose  

Mesenteric ischemia is a condition well-known among physicians treating patients with abdominal symptoms. Even so, mortality rates have not decreased significantly over the last decades. The purpose of this article is to review current treatment concepts of acute and chronic mesenteric ischemia.     

Intestinal ischemia after laparoscopic cholecystectomy.

OBJECTIVES: Intestinal ischemia is a rarely reported complication following laparoscopic cholecystectomy. We describe a case of massive small intestinal necrosis 3 days following this procedure. An autopsy determined the cause to be splanchnic hypoperfusion, likely due to the physiologic changes induced by the pneumoperitoneum necessary to conduct the surgery. We sought to determine whether all reported cases of intestinal ischemia following laparoscopic cholecystectomy (LC) shared the same etiology, and if faulty operative technique could be invoked. METHODS: A review of all known published cases of intestinal ischemia following LC was conducted to determine the underlying etiology of ischemia, and whether adequate operative technique had been observed. RESULTS: Multiple causes of intestinal ischemia following LC have been described: splanchnic hypoperfusion, thrombosis of the superior mesenteric artery, and thrombosis of the inferior mesenteric vein. All occurred despite correct operative technique. CONCLUSIONS: Intestinal ischemia following LC has diverse causes. Patient factors rather than faulty operative technique would appear to underlie the development of this rare complication.     

Intestinal ischemia secondary to thromboangiitis obliterans

A 38-year-old woman presented with a 10-month history of postprandial abdominal pain and weight loss. She smoked two packs of cigarettes a day, but her history did not indicate diabetes mellitus, hyperlipidemia, or hypercoagulability. A lateral aortogram documented complete occlusion of all three mesenteric arteries but showed no evidence of atherosclerosis, arteritis, or medial fibroplasia. Two retrograde aortomesenteric grafts, one to the superior mesenteric artery and another to the meandering mesenteric artery, utilizing the greater saphenous vein were placed. Pathologic examination of the inferior mesenteric artery demonstrated changes that were considered diagnostic of thromboangiitis obliterans. We found only 10 confirmed cases of thromboangiitis obliterans involving the mesenteric vessels in the English language literature. The present case appears to be the first involving a woman and the only one in which the main trunk of all three mesenteric vessels was involved.     

Intestinal ischemia complicating abdominal aortic surgery.

A 9-year experience with 2137 patients undergoing infrarenal abdominal aortic reconstruction was reviewed to determine both the incidence of intestinal ischemia and the clinical, anatomic, and technical factors associated with this complication of aortic surgery. A total of 24 (1.1%) patients had overt intestinal ischemia, documented by reoperation or endoscopic findings. Of these, colon ischemia occurred in 19 (0.9%) and small bowel ischemia developed in 5 (0.2%) patients. The incidence after elective operation for aneurysmal or occlusive disease did not differ, but patients with ruptured aneurysms and those undergoing reoperative procedures for total graft replacement were at higher risk. Preoperative angiography was most helpful in ascertaining risk. Ligation of a patent inferior mesenteric artery was the most common (74%) feature in patients with colon ischemia. With preexisting inferior mesenteric artery occlusion, impairment of collateral circulation was attributable to superior mesenteric artery disease, dissection or retractor injury, prior colon resection, or exclusion of hypogastric perfusion. Bloody diarrhea was the most frequent postoperative symptom and colonoscopy the most reliable means of diagnosis. One half of patients with colon ischemia required resection after late recognition of perforation. All cases of small bowel ischemia were related to superior mesenteric artery disease or injury or use of suprarenal clamping. The overall mortality rate was 25% but rose to 50% if bowel resection was required. Intestinal ischemia remains an infrequent but serious complication of aortic surgery. Despite a multifactorial cause, identification of patients at increased risk can lead to operative strategies to reduce its occurrence.     

Intestinal energy metabolism during ischemia and reperfusion

BACKGROUND. In order to evaluate acute ischemic damage in the small intestine induced by superior mesenteric artery occlusion (SMAO) and subsequent reperfusion, changes in ATP, ADP, and AMP were measured by high-performance liquid chromatography, and changes in tissue blood flow were measured (from the serosal surface) by the laser doppler flow meter in a rat model. MATERIALS AND METHODS. The superior mesenteric artery of the rat was occluded for 30, 60, 90, and 120 min and then reopened. Core temperature was maintained carefully at 37 +/- 0.3 degrees C. RESULTS. All rats that underwent 90 and 120 min of SMAO died within 2 days, but those with 30 and 60 min of SMAO survived. ATP (10.39 +/- 0.90 micromol/g dry weight), ADP (3.34 +/- 0.33), and total adenine nucleotides (TAN; 14.08 +/- 0. 86) decreased with longer SMAO times. After 30 and 60 min of SMAO followed by reperfusion, recoveries of ATP and TAN were relatively good and ADP levels remained fairly steady, but little or no recovery of these levels was observed after 90 and 120 min of SMAO followed by reperfusion. There were linear correlations between the levels of ATP and TAN after 30 min of reperfusion and the time of SMAO. Tissue blood flow levels were constant during SMAO. After reperfusion, those levels were recovered along with the SMAO periods. But recovery rates compared with control values were not related with those of ATP. CONCLUSIONs. ATP and TAN levels, particularly at 30 min after reperfusion, seemed to be in good agreement with the tissue damage and the viability of the small intestine. We propose that the measurement of these levels may be useful for the evaluation of intestinal damage and viability.     

Intestinal brush border enzymes after short-term mesenteric ischemia.

The total activities of sucrase, trehalase, amino-peptidase, and gamma-glutamyltransferase in the isolated brush border of the entire small bowel are reduced to 35, 55, 33, and 21 per cent, respectively, of control values (p less than 0.001) 2 hours after a 45 minute occlusion of the superior mesenteric artery. Since brush border proteins are also reduced by ischemia to 42 per cent of control, enzymatic activity when expressed as U/mg protein is significantly reduced only in the case of gamma-glutamyltransferase, to 48 per cent of control.     

Intestinal ischemia: reduction of mortality utilizing intraluminal perfluorochemical

This study reports an assessment of a method of intestinal protection by the intraluminal administration of an oxygenated perfluorochemical, perfluorotributylamine, or gaseous oxygen in an attempt to provide oxygen for mucosal cells rendered ischemia. A model of acute arterial or acute arteriovenous ischemia was produced in adult female rats. All control ischemic animals died within 12 hours. To assess intestinal protection, the mortality rates in the experimental groups were compared with the 100 percent control mortality. Gaseous oxygen and oxygenated perfluorochemical administered intraluminally reduced mortality significantly in the acute arterial model but not in rats with arteriovenous occlusion. Electron microscopy demonstrated preservation of villi after 1 and 2 hours of occlusion in the oxygen-treated groups. Light microscopy revealed massive destruction in control animals with preserved architecture in both the gaseous oxygen and oxygenated perfluorochemical groups. These results demonstrate that the intraluminal delivery of oxygen to bowel rendered ischemic by arterial occlusion may significantly decrease anatomic bowel disruption and improve animal survival. Such techniques have a potential clinical application to facilitate salvage of ischemic intestine and to augment intestinal preservation.     

Intestinal ischemia complicating ascending aortic dissection: first things first

Typically acute dissections of the ascending aorta are considered operative emergencies with delays in treatment potentially resulting in considerable morbidity and mortality. However, occasionally associated unstable or poorly defined problems (such as neurologic impairment or end-organ ischemia) may warrant further investigation and possible treatment to facilitate safe aortic repair. We present a case of acute ascending aortic dissection associated with an intra-abdominal vascular and enteric catastrophe that was successfully managed prior to aortic repair.     

Intestinal ischemia/reperfusion: microcirculatory pathology and functional consequences

Background  

Intestinal ischemia and reperfusion (I/R) is a challenging and life-threatening clinical problem with diverse causes. The delay in diagnosis and treatment contributes to the continued high in-hospital mortality rate.     

Intestinal ischemia: treatment by peritoneal lavage with oxygenated perfluorochemical

Though the delivery of elemental oxygen to tissues ravaged by anaerobic infection may be useful, little data exists that suggests that such therapy may benefit ischemic tissue. We report the development of a model to test the question that peritoneal lavage with an oxygen containing solution may favorably influence occlusive intestinal ischemia. Adult Sprague-Dawley rats with Nembutal (sodium pentobarbital) anesthesia underwent midline laparotomy; a microvascular clamp was applied to the superior mesenteric artery (SMA); and an inflow and outflow lavage catheter was placed. Treatment groups included control rats undergoing SMA occlusion only without lavage, rats lavaged with albumin during SMA occlusion (medium control), and rats lavaged during SMA occlusion with oxygenated perfluorochemical FC-47 emulsified in albumin (O2-FC-47). The increase in serum L-lactate following occlusion was used as an index of intestinal injury whether the perfusate was maintained at room temperature (28 degrees C) or body temperature (37 degrees C). Beginning with time O, which corresponded to the time of unclamping, subsequent samples were collected at 15, 30, and 60 minutes after a 30-minute SMA occlusion. Sequential lactates in 13 control rats were 4.18, 4.10, 3.88, and 4.52 mmol/L. Albumin lavaged animals had values at 28 degrees C of 2.23, 1.35, 1.8, and 2.44 mmol/L and values at 37 degrees C of 2.22, 1.40, 2.07, and 3.21 mmol/L, respectively. With O2-FC-47 lavage the respective lactates were 1.89, 1.09, 1.32, and 1.44 mmol/L at 28 degrees C and 2.14, 2.19, 2.50, and 2.1 mmol/L at 37 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intestinal ischemia resulting from Buerger's disease: Report of a case

A 42-year-old man who had undergone below-the-knee amputations for Buerger's disease 9 and 14 years earlier required emergency surgery for intestinal ischemia caused by arterial occlusive lesions in the mesentery. The cecum and proximal part of the ascending colon were resected, and marked hyperemic thickening of the wall and severe fibrous adhesions were found. Postoperative angiography revealed occlusions in the superior mesenteric and right external iliac arteries. The resected specimen showed mucosal necrosis of the cecum and circular ulcers at Bauhin's valve and at the ascending colon. Microscopically, small mesenteric vessels were occluded by organized and recanalized thrombi with preserved vascular architecture. The patient has remained free of any further intestinal symptoms for 1 year following his discharge from hospital.     

Intestinal ischemia caused by cocaine ingestion: report of two cases

Ingested cocaine can be a cause of severe bowel ischemia or gangrene. Two cocaine addicts who ingested large quantities of the drug developed severe abdominal symptoms and signs caused by bowel ischemia. In one patient gangrene of the bowel necessitated repeated resections and was followed, several weeks later, by death. The other patient suffered less severe ischemia and the bowel returned to normal. The diagnosis of bowel ischemia should be suspected whenever a cocaine addict has severe abdominal symptoms and signs. The presence of marked leukocytosis suggests bowel gangrene and demands prompt surgical intervention.