Kenneth S. Scher

Perforated diverticula of the jejunum and ileum

Over a ten year period, four patients with inflammation or perforation of non-Meckelian, small intestinal diverticula were treated on the surgical services of Bellevue Hospital. This entity remains uncommon but may be increasing in incidence. The patients presented with a short history of severe abdominal pain, usually accompanied by nausea and vomiting. Each patient also gave a longer preceding history of less well defined abdominal symptoms. The pathogenesis of the small intestinal diverticula is uncertain but may be related to disturbed muscular peristalsis in the small bowel analogous to the changes implicated in esophageal and colonic diverticular disease. The diverticulum may be difficult to demonstrate at operation, and careful exploration for this possibility should be carried out at the time of operation for peritonitis of obscure origin. Segmental resection and end-to-end anastomosis is the treatment of choice.

Methods of Splenic Preservation and Their Effect on Clearance of Pneumococcal Bacteremia

The intravascular clearance of type 3 Streptococcus pneumoniae was studied in Sprague-Dawley rats. Sham celiotomy was performed on 20 animals while another 20 rats underwent splenectomy. Four weeks later, bacteremia was induced by intraperitoneal (IP) injection of S. pneumoniae. Serial cultures of peripheral blood were obtained. Splenectomy produced significant impairment of intravascular clearance of bacteria compared to that noted among control animals (p less than 0.01). Eighty animals were divided into four equal groups: I--splenectomy, II--50% splenectomy with the upper half left in situ connected to the short gastric vessels, III--50% splenectomy with the lower half left in situ connected to the hilar vessels, and IV--splenectomy with implantation of splenic fragments. Pneumococcus was administered IP 16 weeks later. Rats were killed 6 hours after bacterial challenge. Residual splenic tissue was weighed. There was significantly less splenic tissue in Groups II-IV than noted in sham animals after 16 weeks (p less than 0.01). The type of partial splenectomy did not significantly affect the weight of residual splenic tissue 16 weeks later. Implantation did yield viable splenic tissue, though the amount proved significantly less than that resulting from either type of partial splenectomy (p less than 0.01). Mean bacterial counts with time for short gastric (Group II) and hilar (Group III) remnant animals were significantly different from those for the asplenic (Group I) rats (p less than 0.02 and p less than 0.001, respectively). Animals with splenic implants (Group IV) were not significantly different from asplenic rats (Group I). Animals with hilar splenic remnants proved significantly different from those with short gastric splenic remnants (p less than 0.01). Partial splenectomy offers protection against pneumococcal bacteremia, though preservation of the hilar blood supply affords the most benefit. The utility of splenic implantation remains unproven.

Implications of emergency operations on the colon

The records of 137 patients undergoing elective colonic operations and 45 patients requiring emergency large bowel operations were reviewed. The mortality rate was 37.8 percent after emergency operations compared with 5.1 percent after elective operations (p less than 0.001). Patient age was not a significant prognostic variable although physiologic status of the patient had a high correlation with both morbidity and mortality. Complications followed 86.7 percent of the emergency operations and 57.7 percent of the elective operations (p less than 0.001). Respiratory failure, renal and hepatic dysfunction, and cardiac events more frequently followed emergency colonic operations. Intraabdominal complications developed after 57.8 percent of the emergency operations compared with 29.9 percent of the elective operations (p less than 0.005). Colonic resection and primary anastomosis in the elective setting was associated with a 7.9 percent mortality rate. A large bowel anastomosis during an emergency operation resulted in a 70 percent mortality rate (p less than 0.001). When emergency colonic operation included creation of a colostomy the mortality rate was 34.4 percent. Although this mortality rate was substantial, it was significantly better than the 70 percent rate that followed attempted anastomosis under unfavorable circumstances (p less than 0.02).

Impaired clearance of escherichia coli bacteremia in early biliary obstruction

Adult male rats underwent common bile duct ligation or sham celiotomy. At intervals of 7 and 14 days postoperatively, bacteremia was induced by intravenous injection of 10(9) Escherichia coli or intraperitoneal injection of 10(6) E. coli. Serial quantitative blood cultures and quantitative whole organ cultures were obtained. One week after surgery, clearance of bacteremia was impaired in all of the animals. Clearance of intraperitoneally injected E. coli was less efficient in the duct ligation rats. Fourteen days postoperatively, clearance of bacteremia induced by intravenous or intraperitoneal injection had improved in the sham celiotomy rats but was still significantly impaired in the duct ligation rats. An increased number of viable E. coli were recovered from the lungs of duct ligation rats after intravenous administration. We found that rats with obstructive jaundice do not respond normally to a bacteremia challenge. This impairment in reticuloendothelial function can be noted as early as 1 week after common duct ligation.

Duration of antibiotic prophylaxis: An experimental study

An animal wound model was used to evaluate single dose cefazolin, multiple dose cefazolin, and single dose cefonicid in the prevention of wound infection. Incisions made in Swiss-Webster mice were contaminated with either Staph. aureus (1.94 X 10(8) colony forming units) or E. coli (4.39 X 10(8) colony forming units). Five experimental groups were studied. Group I encompassed control animals given saline solution, Group II animals given 10 mg cefazolin preoperatively, Group III animals given 10 mg of cefazolin preoperatively and postoperatively, Group IV animals given 10 mg of cefonicid preoperatively, and Group V animals given 20 mg of cefonicid preoperatively. All medications were given by intraperitoneal injection. Antibiotics were given 1 hour before operation. Postoperative doses were given 4 hours after operation. Incisions were opened 48 hours after surgery and wound bacterial concentrations were determined. After both Staph. aureus and E. coli contamination, each of the four cephalosporin regimens significantly reduced the mean wound bacterial concentrations compared with that of the control animals (p less than 0.001). Each of the four cephalosporin regimens also significantly reduced the number of infected wounds compared with that of the control subjects (p less than 0.001). No significant differences were noted among the four antibiotic regimens with respect to mean wound bacterial concentration or infection rate. In the context of this model, a single dose of cefazolin seems to be equally effective as multiple doses of the drug for surgical prophylaxis. Extended half-life cephalosporins, like cefonicid, do not appear to be more effective than a single dose of cefazolin, which is a much less expensive antibiotic.

Combined use of topical and systemic antibiotics

An animal wound model was used to compare the effectiveness of topical and systemic antibiotics and to examine the validity of using a combined regimen of both routes of antibiotic delivery. Gross infection rates and wound bacterial concentrations were determined after contamination with Staphylococcus aureus or Escherichia coli. Both moderate (10(8) colony-forming units [CFU]) and heavy (10(12) CFU) contamination were studied for each organism. Following moderate contamination, topical and systemic antibiotics were equally effective in reducing both wound bacterial content and infection rate, but there was no benefit from the combined use of both modes of antibiotic delivery. An additive effect of the combined regimen was noted only when the level of wound contamination was heavy.

Impaired bacterial killing in early obstructive jaundice

Sprague-Dawley rats were challenged with intraperitoneal injection of 10(7) Streptococcus pneumoniae 10 days after common duct ligation (BDL) or sham celiotomy (SC). Quantitative bacterial cultures were performed on liver, spleen, lung, kidney, and heart blood samples obtained 4 hours after injection. All 13 (100%) BDL animals had positive heart blood cultures, but only 6 of 12 (50%) SC animals remained bacteremic (p < 0.05). Significantly more viable organisms were recovered from lung, liver, spleen, and kidney of BDL animals compared with SC controls. BDL impaired the hosts ability to kill this encapsulated gram-positive organism. Viable bacteria remained in all organs studied, which was associated with continuing bacteremia.

Anaerobic coverage for wound prophylaxis: Comparison of cefazolin and cefoxitin

An experimental wound model has been used to evaluate the effectiveness of cefazolin and cefoxitin in the prevention of wound infection. Incisions were contaminated with Staph. aureus, E. coli, or a standardized fecal suspension. Regardless of the contaminant employed, the prophylactic use of either cefazolin or cefoxitin yielded lower wound bacterial concentrations and fewer infections compared with treatment with placebo. Cefazolin proved just as effective as cefoxitin in preventing infection when wounds were contaminated with Staph. aureus or E. coli. Although cefoxitin is the only cephalosporin that offers anaerobic coverage, its prophylactic administration when wounds were contaminated with a standardized fecal suspension did not significantly alter wound bacterial concentrations or infection rates compared with cefazolin. The data from our animal wound model suggest that prophylactic anaerobic coverage is not necessary.

Effect of cephalosporins on fascial healing after celiotomy

A 7 day course of either cefonicid or cefazolin significantly reduced mean wound breaking weight after midline celiotomy in Sprague-Dawley rats compared with control animals. This detrimental effect was not seen when each drug was administered as a single preoperative dose. Even a 3 day course of cefonicid was associated with a significant reduction in the weight required to disrupt a healing abdominal closure. An increased incidence of incisional hernias was also noted among animals treated for 7 days with cefonicid or cefazolin. Shorter antibiotic regimens were not associated with an increased frequency of incisional herniation.

Making peer review statistically accountable

BACKGROUND The peer review process used in most hospitals is largely anecdotal, leading to criticisms about the objectivity of the methods employed. METHODS The results of 1,500 consecutive abdominal operations performed by general surgeons working at three hospitals in a single community were reviewed. The outcome profile of each surgeon was compared statistically to the cumulative profile of the surgical community with adjustments for physiologic status of the patient, difficulty of the operation, and indications for surgery. RESULTS A problem surgeon was thus identified whose poor results were significantly different from the rest of the surgical community and could not be explained on the basis of unfavorable patient mix or complexity of the procedures undertaken. CONCLUSIONS Statistical comparison of a surgeons outcome profile with those of his colleagues working in the same practice environment is suggested as an approach to the task of peer review that might prove preferable to the usual retrospective review of problem cases.