Pericardial influence on internal defibrillation energy requirements.

There is no consensus regarding optimal positioning of patch leads for implantation of automatic implantable cardioverter defibrillators. We compared the energy (in joules) required for 50% and 80% successful termination of ventricular fibrillation with titanium-mesh patch leads outside intact normal pericardium and directly on the epicardium in 13 open-chest dogs. Talc was then instilled into the pericardial space to stimulate adhesion formation and pericardial thickening. After 3 weeks of recovery, thoracotomy and defibrillation testing were repeated in nine dogs with the patch leads outside the thickened, adherent pericardium. There were no significant differences in defibrillation energy requirements between locations (p greater than 0.10). In addition, a comparison of electrical impedance measurements at 10 joules showed no significant differences (p greater than 0.30). In this animal model, defibrillation energy requirements were not altered by positioning the patch leads outside normal intact pericardium rather than placing them directly on the epicardium. Furthermore, thickened, adherent pericardium interposed between the patch leads and the heart does not increase defibrillation energy requirements. These data suggest that placement of automatic implantable cardioverter defibrillator patch leads outside the pericardium in patients (including those with pericardial adhesions from previous cardiac operations) will not adversely affect defibrillation efficacy and thus can simplify the implantation procedure.

15-Deoxyspergualin and primate heart transplantation.

15-Deoxyspergualin is a synthetic polyamine that exhibits a novel spectrum of immunosuppressive activity in lower mammals. To define the clinical potential of this drug, we performed 25 abdominal heterotopic heart transplants in Macaca fasicularis. Donor and recipient pairs were selected from ABO-identical animals with negative erythrocyte crossmatches. All recipients received one dose of methylprednisolone sodium succinate at graft reperfusion. Five control recipients received no subsequent immunosuppression. Five recipients received high-dose 15-deoxyspergualin (7.5 mg/kg IM). Five recipients received low-dose 15-deoxyspergualin (2.0 mg/kg IM). Five recipients received cyclosporine (1.0 mg/kg IM). Five recipients received both 15-deoxyspergualin (2.0 mg/kg IM) and cyclosporine (1.0 mg/kg IM). Immunosuppressive agents were administered daily, beginning with the morning of operation, and were continued until the animal was killed or 30 days had elapsed. Graft function was assessed by daily palpation. Median graft survival among control recipients was 9 days (range, 6 to 34 days). At the dose used, cyclosporine alone did not influence either graft survival time (median survival, 13 days; range, 7 to 23 days) or rejection grade. Graft survival and rejection grade among recipients treated with low-dose 15-deoxyspergualin were not different from control recipients or those treated with cyclosporine alone (median survival, 10 days; range, 8 to 39 days). One recipient, killed on postoperative day 8, had an intraadominal abscess. In each of the recipients treated with high-dose 15-deoxyspergualin systemic toxicity developed, and the animal was killed when death appeared imminent, although graft contraction remained vigorous (median survival, 28 days; range 25 to 30 days).(ABSTRACT TRUNCATED AT 250 WORDS)

Balloon dilatation of gastro-gastrostomy strictures in gastroplasty revisions.

Several gastric operations have been developed for the control of morbid obesity. Further surgical intervention may be necessary because of failure to lose weight or complications associated with the previous operation such as intolerable reflux symptoms. Revision from a horizontal to a vertical staple line may result in a stenosis at the site of the gastro-gastrostomy. This study examines the authors' experience with balloon dilation of these strictures. Between May, 1981 and September, 1987, 12 of 113 patients who had revision of previous gastric reduction procedures developed either gastro-gastrostomy stenosis or stenosis above the Marlex collar (2 patients). Endoscopic balloon dilatation was attempted in all 12 patients. Eight females and four males (average age, 42 years) had undergone either a previous vertical banded gastroplasty (VBG) (2 patients), gastric bypass, or horizontal gastroplasty as their initial operation. Revision was performed for failure of the initial operation to control weight, obstructive symptoms, or gastroesophageal reflux. Balloon dilatation was possible in 11 of 12 patients. The majority required less than four dilations to alleviate obstructive symptoms. Balloon dilatation is effective in the management of gastro-gastrostomy stenosis following revision of gastric stapling procedures.