Preoperative cardiac evaluation of the patient with vascular disease.

OBJECTIVE: To review the literature and evaluate the investigation of cardiac risk factors, by tests and intraoperative predictors, that will identify patients at high risk for vascular surgery. DATA SOURCES: An English-language literature review of Index Medicus articles from 1961 to 1992. STUDY SELECTION: Published articles that addressed preoperative risk factors, diagnostic tests and intraoperative predictors were selected by multiauthor consensus. DATA EXTRACTION: Independent extraction by multiple authors was utilized to abstract and assess the quality of data from selected references, with consensus determining inclusion or exclusion. DATA SYNTHESIS: From evaluation of published data, a number of factors were considered to put a patient scheduled to undergo vascular surgery at higher risk: symptomatic coronary artery disease; clinical evidence of coronary artery disease, congestive heart failure, aortic stenosis and recent myocardial infarction; laboratory findings of significant disease with cardiomegaly or significant dysrhythmias; and no symptoms but two or more risk factors. CONCLUSIONS: The authors propose an algorithm for the investigation of patients and stratification of risk to be considered in weighing the dangers versus the benefits of vascular surgery.

Piperacillin versus cefazolin given perioperatively to high-risk patients who undergo open cholecystectomy: a double-blind, randomized trial.

OBJECTIVE: To study the efficacy, microbiologic features and toxicity of prophylactic cefazolin versus prophylactic piperacillin in high-risk patients who undergo open cholecystectomy. DESIGN: Double-blind randomized trial with follow-up for 6 weeks postoperatively. SETTING: An 850-bed community hospital, located in a major Canadian city. Patients admitted to hospital who satisfied published criteria for being at high-risk for infection after open cholecystectomy were entered into the protocol, and those who satisfied the criteria and provided consent were entered into the study. Eighty-one patients were randomly assigned by computer to receive either piperacillin or cefazolin as the prophylactic agent. INTERVENTIONS: Open cholecystectomy. MAIN OUTCOME: Provides detailed information on the organisms found in the biliary tree in patients with acute cholecystitis, assesses the in-vitro activity of cefazolin versus piperacillin against the isolated organisms, expecting that piperacillin would be much more active against isolated anaerobes and gram-negative bacteria. RESULTS: Bactobilia was documented in 42% of patients in the cefazolin group and 29% of patients in the piperacillin group. Piperacillin was active in vitro against 94% of all isolates versus 56% for cefazolin (p < 0.005, McNemar's test). Adverse effects and toxicities in both the piperacillin and cefazolin group were low and were not serious. CONCLUSIONS: Both piperacillin and cefazolin are safe and effective prophylactic antimicrobials for high-risk patients who undergo open cholecystectomy. However, piperacillin had a much wider spectrum of in-vitro activity against the isolated pathogens, especially Enterococcus sp., Enterobacter cloacae and the anaerobes.

Selection of antibiotic coverage in vascular patients undergoing cystoscopy.

Bacteremic seeding of prosthetic vascular grafts represents a cause for graft infection; transurethral procedures account for one source of bacteremia. Therefore, a prospective study of 200 patients undergoing cystoscopy was conducted to identify the incidence of bacteruria and factors associated with it, organisms involved and their antibiotic sensitivities. Positive cultures were found in 21%. The incidence was 64% in in-patients and 8% in out-patients. Positive cultures were found in 12% of patients who received antibiotics and 29% who did not. Four percent showed signs of bacteremia. The cultures identified both Gram positive and negative organisms; multiple organisms grew in 22%. Gram negative organisms were more common in in-patients. Candida grew in 8%. The Gram positive organisms were sensitive to ampicillin (92%), sulfatrimethoprim (75%) and cefazolin (60%); Gram negative to aminoglycosides (100%) and cefazolin (92%). In view of the unpredictable and multiple organisms, it is recommended that pre-cystoscopy cultures be performed and specific antibiotic coverage be based on the sensitivities.

Intraoperative bacterial contamination of vascular grafts: a prospective study.

The establishment of graft infection depends on host response, an appropriate field and bacterial contamination. Intraoperative bacterial contamination of prosthetic graft material was studied prospectively in 77 patients. Vascular reconstruction was indicated for abdominal aortic aneurysm (15%), claudication (42%), rest pain (25%) and ulceration or gangrene (18%). In 78% of cases the procedure was elective. Staphylococcus epidermidis was isolated in 80% of cultures; mixed flora were more frequent in patients with rest pain (60%) and ulceration or gangrene (45%) than in those with aneurysms (22%) or claudication (16%). Grafts became contaminated in 56% of cases using standard techniques; this was lowered to 35% when the surgeon changed gloves before preclotting the graft. There was no significant difference with respect to the surgeon who performed the operation, the indication for operation, primary versus secondary repair or the use of skin barriers. One patient (1.3%) had an established graft infection. It is concluded that the incidence of contamination is high but may be decreased by glove changing.

Survival following complete detachment of an end-to-end aortic anastomosis.

A 78-year-old man had complete dehiscence of the suture line of the aorta to a prosthesis, 8 years after standard repair of an abdominal aortic aneurysm. For 6 months, until the aortic was reconstructed, the patient had no hemorrhage or limb ischemia because a conduit was maintained by the original aneurysm wall which had been wrapped around the prosthesis. The authors believe this is the first report of survival following such dehiscence. They advocate the use of non-absorbable sutures when anastomosing the graft to the aorta and repair rather than resection of abdominal aortic aneurysms.

Femoropopliteal bypass: saphenous vein and expanded polytetrafluoroethylene grafts.

The patency of 181 saphenous vein and expanded polytetrafluoroethylene (PTFE) femoropopliteal bypass grafts was assessed during a follow-up that ranged from 1 to 53 months after operation. Significantly better patency (P less than 0.05) was noted with saphenous vein (70%) than with PTFE (56%). Life-table analysis at 30 months demonstrated a cumulative patency of 50% for saphenous vein grafts versus 39% for PTFE, while at 53 months the rates were 46% and 33% respectively. The PTFE grafts tended to occlude earlier than saphenous vein grafts but after the initial year, both types of graft failed at a rate of about 5% a year. Patency was similar in both groups when operation was performed for claudication, but for limb salvage operations saphenous vein patency was superior to PTFE. Although the groups were similar in constitution, a higher percentage of patients in the PTFE group had undergone previous vascular operations.

Fate of the limb after failed femoropopliteal reconstruction.

Sixty-eight occluded femoropopliteal bypass grafts were studied to determine the fate of the limb after graft occlusion. There were 25 reversed saphenous vein grafts and 43 polytetrafluoroethylene grafts. Thirty-five limbs required amputation and the timing of amputation after graft thrombosis ranged from 1 day to 24 months. Twenty of the amputations occurred following an unsuccessful revision of the thrombosed graft and an additional 15 limbs were amputated without further attempts at revascularization. In 17 of the patients there were no disabling signs or symptoms after graft occlusion. Twenty-two grafts were successfully revised to avoid amputation. The need for amputation and the level of amputation were analysed with respect to the age of the patient, the indication for the original procedure, inflow and outflow status, the type of graft and the level of distal anastomosis. In 26 patients with intermittent claudication only four amputations resulted from graft occlusion and these were all below the knee. There was a weakly significant (P less than 0.1) correlation between poor outflow and the need for amputation after occlusion of the graft. In particular, patients with femorodistal bypass faired poorly, four of five occluded saphenous vein grafts and all six PTFE grafts requiring amputation. There was no significant age difference with respect to the level of amputation or the need for amputation and there was a wide range from the time of thrombosis to amputation. The authors conclude that amputations are infrequent after bypass grafting for claudication. The level of distal anastomosis, poor inflow and run-off and gangrene before the bypass procedure all correlate with the need for amputation in thrombosed grafts initially placed for limb salvage. Vigorous attempts at revision of failed grafts may prevent or constructively delay amputation.

Unsuspected phaeochromocytoma presenting during surgery.

A patient with an unsuspected phaeochromocytoma presented with transient hypertension during anaesthesia for an elective hernia repair, and developed severe post-operative hypotension. The management of this acute crisis, appropriate preoperative preparation and the subsequent successful removal of the tumour is described. Awareness of this unusual presentation may help the attending physician to save such a patient.

Intra-arterial alprostadil for nonatherosclerotic vasculopathy.

A 33-year-old man with a nonatherosclerotic vasculopathy of undetermined origin had progressive occlusive disease of the lower limb vessels. The resultant severe rest pain and ischemic ulceration of his foot were inoperable and unresponsive to conventional drug therapy. Treatment was begun with intra-arterially administered alprostadil (prostaglandin E1), a vasodilator and inhibitor of platelet aggregation. Although immediate benefit was equivocal, his rest pain had disappeared six weeks after infusion, and the ischemic ulcer almost healed completely. Blood flow studies showed increased flow to the feet, consistent with the subjective improvement. The beneficial effect of alprostadil suggests that further studies with this agent are warranted for patients with nonatherosclerotic vasculopathy.