Exclusion of AAA from circulation was feasible, safe, and clinically effective with the new stent-graft.

The incidence of perioperative complications after coronary artery surgery was investigated by a retrospective study of all 502 patients undergoing coronary artery bypass graft (CABG) surgery in our Department between January 1st and December 31st of last year (1990). Furthermore, the influence of obesity on the early results of surgery was assessed and the effect of preoperative weight reduction on perioperative complication rates examined. Obese patients had a greater incidence of left-stem coronary artery stenosis (p less than 0.001), hyperlipidaemia (p less than 0.05), hypertension (p less than 0.05), diabetes mellitus (p less than 0.02), and were in general younger at the time of operation (57.9 +/- 8.4 vs. 60.8 +/- 8.5 years). There were no differences in the surgery performed and in operative mortality, but there were some in perioperative morbidity. Obese patients had higher rates of infection (p less than 0.02), sternal dehiscence (p less than 0.02), arrhythmias (p less than 0.02) and myocardial infarction (p less than 0.02). No significant differences were identified in obese patients with or without preoperative weight reduction, although there was a trend of better postoperative recovery and results in patients having undergone preoperative weight reduction. Analysis of our results demonstrated obesity to be an independent risk factor for perioperative complications, hospital morbidity, and length of hospitalization.

The efficacy of the human angiogenetic heparin-binding growth factor I (HBGF-I) to initiate site-directed growth of new blood vessels from the aorta into the myocardium was studied. First, manipulated Escherichia coli bacteria, which had received the human mRNA-transcript for HBGF I into their genetic material, were cultivated. The growth factor derived was purified using heparin-Sepharose affinity chromatography. The separation and characterization of biologically active alpha- and beta-chains was carried out using high pressure liquid chromatography (HPLC) of dialyzed and lyophilized samples from the heparin-Sepharose column. One microgram HBGF I (alpha-ECGF) was bound to polytetrafluoroethylene (PTFE) sponges, precoated with collagen type I, and implanted between the aorta and the myocardium of the left ventricle in experimental rats. Twelve growth factor implants in the experimental group were compared to six controls receiving uncoated PTFE sponges for 9 weeks. Digitized computed angiography showed new blood vessels between the aorta and the myocardium in 11 of the 12 experimental animals, and retrograde coronary perfusion by these "new" vascular structures could be seen. Histology showed no specific structures in the control group (without HBGF I). In the experimental group (with HBGF I) individual vessels with highly differentiated endothelial and smooth muscle cell layers were evident. Our experiments proved the feasibility of induced, site-directed angiogenesis. It is possible to initiate in vivo growth of new "coronary" vascular structures between the aorta and the myocardium.

To determine the prolongation of hospital stay due to postoperative wound infections following cardiac surgery, a prospective cohort study was performed by matching multiple control patients without infection to each infected patient (= case). Out of 22 cases, no patient died. No case had to be excluded from the matching process because of a lack of suitable control patients. The maximum number of controls per case was 10. The mean added stay was 12.2 days constituting a considerable prolongation of stay due to wound infection in cardiac surgery.

In 91 patients undergoing elective coronary bypass grafting, the anti-ischemic and anti-arrhythmic efficacy of a 24-hour infusion of either the calcium antagonist diltiazem (0.1 mg/kg per h, n = 44) or nitroglycerin (1 micrograms/kg per min, n = 47) were compared. Myocardial ischemia was diagnosed by Holter monitoring and the repeated assessment of 12-lead ECG and serum enzyme levels and defined as a transient ischemic event, transient coronary spasm or myocardial infarction. The two groups did not differ with respect to preoperative and operative data. Postoperatively, the average heart rate and pulse pressure rate were significantly lower in the diltiazem group. The incidence of postoperative atrial fibrillation (4.5 vs 19.1%, P < 0.01), transient coronary spasm (2.3 vs 11.4%, P < 0.05) and myocardial infarction (4.5 vs 8.5%, not significant) and the frequency of ventricular premature couplets/h (12.1 +/- 4.5 vs 18.1 +/- 5.1, P < 0.05) and ventricular runs/h (2.5 +/- 0.8 vs 6.5 +/- 2.8, P < 0.05) were lower in the diltiazem as compared to the nitroglycerin group. In addition, diltiazem-treated patients had significantly lower postoperative peak values of creatine kinase-MB (19.3 +/- 11.6 vs 29.3 +/- 20.6, P < 0.05). In conclusion, perioperative infusion of diltiazem is effective in reducing the incidence and extent of arrhythmias and myocardial ischemia in patients undergoing elective coronary bypass grafting as compared to patients receiving nitroglycerin.