Limb ischemia: surgical therapy in acute arterial occlusion.

Mortality and amputation rates from acute arterial occlusion are reported from 7 to 37 per cent and 10 to 30 per cent, respectively. Recent data from thrombolysis or peripheral arterial surgery suggest no significant differences between initial management with surgical or thrombolytic therapy. Mortality and amputation rates were in the above ranges. The last 230 procedures (216 patients) over 10 years were reviewed. All graft occlusions, cardiac catheterization injuries, and aortic balloon-related thromboses were excluded. Immediate and delayed amputation rates were 6.5 and 0.9 per cent. Death occurred in 21 patients (9.7%), with only 6 deaths over the last 6 years (3.8%). Except for transesophageal echocardiography, perioperative studies were of limited value. Long-term anticoagulation was also not effective in preventing recurrent episodes. A mortality rate of 9.7 per cent and amputation rate of 7.4 per cent justifies an early aggressive surgical approach. Limited perioperative studies and less prolonged anticoagulation may also improve cost containment.

Comparison of laparoscopic cholecystectomy with open cholecystectomy in a single center.

In this retrospective study, we compared the results of 1,283 open cholecystectomies (OCs) performed at our medical center during the pre-laparoscopic era with 1,107 laparoscopic cholecystectomies (LCs) performed from 1990 to 1992. There was no difference in the percentage of cases of acute and chronic cholecystitis in each time period (16.8% in each), nor were there differences in the patient characteristics for each group. The percentage of patients undergoing intraoperative cholangiography was similar for patients with chronic cholecystitis for each period, although the incidence of abnormal cholangiograms was lower in the laparoscopic era (5.8% versus 15.2%, p < 0.001). There was one bile duct injury in the OC group and three in the LC group (although one of these occurred after conversion ot an open procedure), but this difference was not statistically significant. However, there was a higher mortality rate in the patients with acute cholecystitis treated with OC (2.3% versus 0%, p = 0.03) and an increase in the overall complications in the patients with chronic cholecystitis in the OC group (7.5% versus 3.1%, p < 0.001) compared with the LC group. The increase in overall complications appeared to be primarily related to the increased rate of wound-related complications (3.6% versus 0%, p < 0.001) in the patients with chronic cholecystitis in the OC group. LC appears to be a safe procedure with a low incidence of complications including bile duct injury when performed by adequately trained surgeons.

Muscle amino acid flux in patients receiving branched-chain amino acid solutions after surgery.

The metabolism and efficacy of branched-chain amino acids (BCAAs)-enriched parenteral solutions in patients after surgery are unclear. This prospective clinical study compared two groups of patients (n = 13) receiving either a 25% BCAA solution or a 45% BCAA solution at 30 kcal/kg/day and 1.5 gm protein/kg/day for 7 days after operation. Whole-body nitrogen balance and forearm muscle amino acid and ketoacid flux were measured. There were no significant differences between the two groups in mean cumulative nitrogen balance (+13.1 gm versus +18.0 gm) between the two groups. Patients receiving the 45% BCAA solution had significant mean uptake of total BCAA, leucine, and isoleucine compared with results in patients receiving the 25% BCAA solution. Despite this increased uptake of BCAA in the 45% BCAA group, there was no increased efflux of alanine, glutamine, or the BCAA ketoacids, ketoisocaproic, ketoisovaleric, or ketomethylvaleric. However, increased release of aspartate was noted in the 45% BCAA group compared with the 25% BCAA group. Thus use of a 45% BCAA-enriched solution infused in patients after surgery results in a significant increase in forearm muscle uptake of the BCAA that is not demonstrated in whole-body nitrogen economics.

Alteration of methotrexate toxicity in rats by manipulation of dietary components.

Administration of a chemically defined, elemental diet to rats given 20 mg/kg of methotrexate intraperitoneally has consistently resulted in a 100% mortality from severe enteritis within 156 h. This study examined the importance of specific dietary components in the etiology of this enhanced toxicity. Rats were given their respective diets for 7 days, whereupon methotrexate (20 mg/kg) was given intraperitoneally, and percent of survivors was recorded. Varying the concentration of carbohydrate as polysaccharide (0%, 50%, 100%) (n = 30) had no effect on survival. An increase in the percent of protein as polypeptide (0%, 25%, 50%, 75%, 100%) (n = 50) in the elemental diet resulted in a progressively significant increase in percent survival. Addition of either fat or bulk to this elemental diet had no effect on survivorship. Serum and bile methotrexate levels of rats fed an elemental liquid diet (whether or not all of the protein was provided as polypeptide) were significantly increased from 12 to 72 h (p less than 0.03) compared with rats fed a regular Chow diet. When the protein content of the elemental liquid diet was provided as 100% polypeptide, serum and bile methotrexate levels were significantly lower at 48 h compared with the elemental diet group given 100% of protein as amino acid. Administration of methotrexate to rats fed an elemental liquid diet in which all of the protein is provided as amino acids is extremely toxic to the gastrointestinal tract, probably as a result of delayed clearance of the drug from the systemic circulation and from bile. This toxicity is alleviated by the provision of protein as polypeptide in the elemental diet. No toxicity to the drug is seen at this dose in rats fed a regular Chow diet. If these results are applicable to humans, the use of elemental liquid diets as the only source of enteral nutrition would appear contraindicated in patients receiving methotrexate.

Immediate postoperative jejunostomy feeding. Clinical and metabolic results in a prospective trial.

A prospective clinical trial was designed to evaluate the efficacy of postoperative jejunostomy feedings using high (44 percent) and low (15 percent) branched-chain amino acid elemental diet formulations compared with no jejunostomy feedings in a homogeneous surgical population. Twenty-eight patients undergoing radical cystectomy and ileal diversion were randomized to the high branched-chain amino acid formula (11 patients) or the low branched-chain amino acid formula (9 patients). Eight patients received a 5 percent dextrose in water solution intravenously and served as a control group. Mean caloric intake per day in each group was 1,543 calories, 1,697 calories, and 550 calories, respectively; whereas the mean nitrogen intake of each group was 6.5 +/- 2.1 g/day, 8.2 +/- 2.4 g/day, and 0 g/day, respectively. Mean weight changes were minus 0.7 percent, 0.7 percent, and minus 0.3 percent, respectively. The mean daily nitrogen balance was minus 1.6 +/- 3.5 g/day, minus 1.1 +/- 4.4 g/day, and minus 6.6 +/- 1 g/day (p less than 0.001). Five patients (25 percent) in the jejunostomy groups progressed to an oral diet more rapidly than the control group, but gastrointestinal complications occurred in 11 patients (55 percent). Immediate postoperative jejunostomy feedings resulted in improved nitrogen balance compared with the control group values, but no metabolic advantage was noted by infusing a high branched-chain amino acid formula. Improved return to normal gastrointestinal function was noted in 25 percent of jejunostomy patients, but the gastrointestinal complications noted limited the overall usefulness of this technique.

High-branched chain amino acid solutions: relationship of composition to efficacy.

A prospective clinical trial was undertaken to determine the nitrogen-sparing efficacy of three amino acid solutions with different concentrations of branched-chain amino acids (BCAA) in 25 postoperative patients. The patients were a homogenous male population with stage I bladder cancer who underwent radical cystectomy. Administration rates of the intravenous solutions were designed to provide 30 kcal/kg/day and 1.5 g protein per kg per day during the 7-day study period. A control group (n = 4) received 5% dextrose in water (150 g/day). Nitrogen balance was determined daily and the whole body protein turnover was measured using a primed-constant infusion of 15N glycine on postoperative days 3 and 4. The group receiving the 45% BCAA enriched (low leucine) amino acid solution exhibited a significant decrease in cumulative (7 day) nitrogen balance (7.6 +/- 2.6 g) compared to the groups receiving either the standard 25% BCAA (19.9 +/- 2.1 g) or the 45% BCAA enriched (high leucine) (21.6 +/- 7.0 g) amino acid solution. The group receiving the 45% BCAA enriched (low leucine) amino acid solution exhibited a higher rate of mean whole body protein catabolism compared to the other groups. For patients undergoing major elective operations, the amount of leucine necessary for optimal daily nitrogen balance was 0.13 g/kg/day. These results demonstrate that the ratio of individual BCAA and the amount of leucine were more critical to nitrogen-sparing efficacy than the percentage total BCAA infused.

Colonic manifestations of collagen vascular diseases.

Upper gastrointestinal manifestations of collagen vascular diseases have been well described. Recently our attention has been focused on the colonic complications: fibrosis and stricture resulting in obstruction, severe obstipation and recurrent fecal impactions secondary to pseudo-obstruction, progressive colonic dilatation resulting in gangrene of the colon, and sigmoid volvulus and diverticulitis in the presence of both wide- and narrow-mouth pseudodiverticula. Patients with these colonic manifestations of collagen vascular disease are disabled, if not severely ill. Recognition of the problem enables the surgeon to plan definitive surgical intervention ranging from segmental resection to total colectomy and ileoproctostomy to restore satisfactory large bowel function.