Improved outcome by identification of high-risk nonocclusive mesenteric ischemia, aggressive reexploration, and delayed anastomosis.

BACKGROUND: The factors associated with outcome of patients with nonocclusive mesenteric ischemia are poorly defined. METHODS: Over a 7-year period, 34 consecutive patients with nonocclusive mesenteric ischemia were identified. RESULTS: The mean age of the study patients was 63 years (range 31 to 94); 21 of 34 (62%) were men. The mean delay in diagnosis was 31 hours (range 7 hours to 6 days). Seven of 34 (21%) underwent preoperative visceral arteriography. Two of these 7 required surgery, and both died as a result of intestinal infarction. The remaining 27 had the diagnosis made at celiotomy. Among the 29 who were explored, 16 of 29 (55%) had intestinal infarction. Twenty-one of 29 (72%) had segmental bowel injury whereas 8 of 29 (28%) had massive injury. Among those with segmental infarction, primary anastomosis was performed in 12 of 21 patients (57%); 5 of the 12 (42%) died. Nine of 21 patients (43%) underwent delayed anastomosis; 2 of the 9 (22%) died. No patient with massive injury underwent primary anastomosis. Second-look laparotomy was performed on 22 of 29 (76%). Eleven of those 22 (50%) had a further bowel resection. Overall, 16 of 29 (55%) who underwent surgery for nonocclusive mesenteric ischemia are alive. CONCLUSIONS: Improved survival from nonocclusive mesenteric ischemia is dependent upon the identification of high-risk groups, aggressive reexploration, and delayed intestinal anastomosis.

The effect of volume and number on fragmentation of gallstones by lithotripsy.

Several factors may affect the fragmentation of gallstones by lithotripsy. We hypothesized that stone volume is an important determinant of degree of fragmentation, while number of stones is less important. The volume of 30 single stones was measured in vitro by water immersion. Thirty sets of multiple stones were matched with single stones of similar volumes. The stones were subjected to 750 shock waves (18 kV) with the Dornier MPL 9000 lithotripter. Degree of fragmentation was assessed by passing fragments through sieves of 1, 2, and 4 mm and recording percentage of stone weight which passed through each sieve. The mean percentage of stone weight passing through sieves of 1, 2, and 4 mm for single stones was 38.2, 49.4, and 59.8. The corresponding values for multiple stones were 46.4, 61.3, and 75.4. These values were not significantly different at P less than or equal to 0.05. Thus, there was no significant difference in fragmentation between single and multiple stones when their volumes were similar. The mean volume of stones with 100% of fragments less than 4 mm (0.80 +/- 0.05 cc) was significantly less than that of stones with fragments greater than 4 mm (1.95 +/- 0.14 cc) (P less than 0.0001). There was a significant inverse linear correlation between stone volume and degree of fragmentation (r = -0.65). We conclude that stone volume is an important determinant of degree of fragmentation and may be the most important criterion in selecting patients for lithotripsy. In this in vitro setting, stone number alone had no effect on degree of stone fragmentation.