Revascularization of the superior mesenteric artery.

From 1965 to 1973, 7 patients with severe chronic mesenteric vascular insufficiency have been successfully operated upon. Abdominal pain, weight loss and epigastric murmur were the most significant symptoms and signs in these diffusely atheromatous patients. Aortography with exposure in the lateral projection was essential for diagnosis and operative planning. Although two and often all three main splanchnic arteries were involved, revasculariztion of only the superior mesenteric artery restored normal hemodynamics. There was no operative mortality. Weight gain was dramatic and post-prandial pain disappeared in all patients. One patient diedone year and one half after the operation from an acute cerebro-vascular accidnet. Our surgical experience in this field, although small, is very gratifying and rewarding.     

Surgical treatment of nonocclussive mesenteric infarction

Two cases of nonocclusive mesenteric vascular disease associated with stenosis of the superior mesenteric artery are described. In one patient with congestive heart failure and atrial fibrillation treated with digitalis, the first episode after a bout of sepsis was treated supportively, but a stricture of the ileum secondary to full thickness intestinal infarction resulted. His second episode required emergency ileal resection for perforation. The superior mesenteric artery was subsequently reconstructed with an aortomesenteric bypass. The second patient had segmentai intestinal necrosis occurring in association with superior mesenteric artery narrowing without total occlusion.     

Revascularization of the superior mesenteric artery alone for treatment of intestinal ischemia

OBJECTIVE: Complete revascularization is recommended by many authors for treatment of intestinal ischemia. The observation that postprandial intestinal hyperemia is limited to the superior mesenteric artery (SMA) has suggested to us that SMA revascularization alone should be adequate treatment. We preferentially manage intestinal ischemia with a single bypass graft to the SMA and herein update our results using this approach. METHODS: Patients were identified from a prospectively established vascular surgical registry. Each patient was assessed for acute versus chronic intestinal ischemia, preoperative angiographic findings, operation used, perioperative morbidity and mortality, late symptomatic relief, cause of death, and life table-determined survival and graft patency. Graft patency was determined by follow-up angiography or duplex scanning. RESULTS: Fifty bypass grafts to the SMA alone were performed in 49 patients (31 women, 18 men; mean age, 62 years) for treatment of intestinal ischemia. In all patients additional splanchnic arteries were available for bypass grafting. Operative indications were acute symptoms in 21 patients, 14 of whom had bowel infarction; chronic symptoms in 26 patients; and prophylaxis in conjunction with infrarenal aortic surgery in 3 patients. Thirty-two grafts originated from the aorta or an iliac artery, and 18 originated from an aortic graft. There were 40 prosthetic and 10 autogenous conduits. Perioperative mortality was 3% in patients with chronic symptoms and 12% overall. All survivors were symptomatically improved. Mean follow-up was 44 months. Nine-year assisted primary graft patency was 79%, and 5-year patient survival was 61%. Two late deaths occurred in patients with recurrent intestinal ischemia resulting from graft occlusions. CONCLUSIONS: Bypass grafting to the SMA alone appears to be both an effective and durable procedure for treatment of intestinal ischemia. Our results appear equal to those reported for "complete" revascularization for intestinal ischemia. When the SMA is a suitable recipient vessel, multiple bypass grafts to other splanchnic vessels are unnecessary in the treatment of intestinal ischemia.     

Treatment of mesenteric infarction

Eighty-one cases of mesenteric infarction documented by angiography, laparotomy or autopsy were reviewed to assess the cause of the persistently high mortality. Thirty-seven patients (46 per cent) were felt to have inoperable lesions and were treated by supportive care only, while forty-four (54 per cent) underwent bowel resection and/or revascularization. Of these 44 patients 20 (45 per cent) survived, 14 (32 per cent) died of an early recurrence of infarction and 10 (23 per cent) died of an unrelated cause. In view of the high recurrence rate in the early postoperative period, treatment must prevent the causes of persistent or recurrent ischaemia such as vasoconstriction and reperfusion tissue damage. On the basis of recent clinical and experimental research we suggest that treatment should include routine angiography with selective perfusion of vasodilators through the superior mesenteric artery, pharmacological prevention of ischaemic and reperfusion tissue damage before surgery, and postoperative anticoagulation.     

Revascularization of the superior mesenteric artery after acute thromboembolic occlusion

BACKGROUND: The outcome and prognostic factors after revascularization of acute thromboembolic occlusion of the superior mesenteric artery (SMA) are poorly documented. METHODS: Sixty patients with acute thromboembolic occlusion of the SMA had revascularization procedures at 21 hospitals from 1987 to 1998. They were registered prospectively in the Swedish Vascular Registry. Patient files were analysed retrospectively. RESULTS: The median age of the patients was 76 years; 73 per cent suffered from cardiac disease and 23 per cent had previous vascular surgery. Onset of symptoms was classified as sudden (30 per cent), acute (33 per cent) or insidious (37 per cent). The occlusions were thought to be either embolic (67 per cent) or thrombotic (33 per cent). The diagnosis was suspected on first examination in 32 per cent of patients, a group whose median time to operation was shorter (P = 0.01). Fifty-eight patients had an exploratory laparotomy and subsequent revascularization, and two were treated with thrombolysis alone. Second-look laparotomy was performed in 41, and third look in eight patients; 19 required an additional bowel resection. The overall mortality rates were 43, 52, 60 and 67 per cent at 30 days, discharge, 1 and 5 years, respectively. No patient was dependent on intravenous nutrition after 1 year. Previous vascular surgery resulted in a higher institutional mortality rate (79 per cent; P = 0.02). Patients who had a sudden onset of symptoms outside hospital had a better outcome (mortality rate 27 per cent; P = 0.02). CONCLUSION: Many non-diagnostic radiological examinations were performed and a routine second-look is warranted. The results suggest that attempts at revascularization procedures for acute mesenteric ischaemia may improve the outcome.     

Nonocclusive mesenteric infarction in hemodialysis patients

BACKGROUND: Dialysis patients develop nonocclusive mesenteric ischemia (NOMI) at an increased rate. Previous studies have associated atherosclerosis and hemodialysis-induced hypotension as inciting factors for NOMI development. A retrospective review of 29 of 1,370 longterm hemodialysis patients who developed NOMI from January 1992 to December 1997 was performed. The NOMI patients were compared with a similar profile of hemodialysis patients to identify risk factors for the development of NOMI and for outcomes assessment. STUDY DESIGN: All NOMI patients had hypotensive episodes during hemodialysis the week before the development of abdominal symptoms, and additional risk factors of hypertension (83%), diabetes (55%), and atherosclerosis (38%). The majority of patients (83%) experienced abdominal pain more than 24 hours before admission. Sixty-six percent of patients had leukocytosis on admission laboratory data. RESULTS: Sixteen patients (55%) had ischemia of the small bowel, all underwent laparotomy, and nine (56%) died. Thirteen patients (45%) had ischemia of the colon and were managed nonoperatively; four (31%) of them died. Overall mortality rate for NOMI was 45%. CONCLUSIONS: NOMI occurs at an increased rate in hemodialysis patients. Identification of patients at high risk for NOMI and dose monitoring of filtration rates may impact on the high mortality of this disease.