Hemostatic efficacy of fibrin sealant (human) on expanded poly-tetrafluoroethylene carotid patch angioplasty: a randomized clinical trial.

PURPOSE: The efficacy of solvent-detergent-treated fibrin sealant (human [FSH]) for controlling anastomotic bleeding from expanded polytetrafluoroethylene (ePTFE) patch angioplasty during carotid endarterectomy was evaluated, and FSH was compared with thrombin-soaked gelatin sponge (Gelfoam; TSG). METHODS: The study was of a randomized, open-label, single-site, single-treatment, parallel design that took place in a referral center with hospitalized patients. Forty-seven adult patients (33 men, 14 women) underwent elective carotid endarterectomy. Patients were randomized to receive either FSH (N = 24) or TSG (N = 23). FSH was obtained as an investigational new drug. FSH was applied as a liquid by means of a dual-syringe technique. Heparin anticoagulation, patch thickness, and suture type were standardized. Two different needle sizes were used (CV-6, PT-13: N = 21 [FSH: N = 10, TSG: N = 11]; CV-6, PT-9: N = 26 [FSH: N = 14, TSG: N = 13]). The FSH or TSG was applied to the ePTFE patch, and then blood flow was restored through the carotid artery. Degree of anticoagulation was assessed by anti-factor Xa activity. The time from restoration of carotid blood flow until achieving hemostasis was recorded. The blood loss from patch suture hole bleeding was measured. Completion intraoperative duplex ultrasound scanning was performed in all cases. Heparin was reversed with protamine sulfate. The primary end point was successful hemostasis within 15 minutes of restoration of carotid blood flow. The secondary end points were the amount of blood loss caused by suture line bleeding and the time to achieve hemostasis. RESULTS: There was no difference in the number of patients with complete hemostasis at 15 minutes (TSG, 13 of 23; FSH, 12 of 24; P =.77). The measured blood loss was 99.0 +/- 119.9 (SD) mL for TSG, and 105.0 +/- 107.9 mL for FSH (P =.86). The time to hemostasis was the same for both groups (TSG, 16.5 +/- 16.5 minutes; FSH, 16.6 +/- 14.2 minutes; P =.97). Within both treatment groups, the use of larger needles (PT-13) was associated with greater blood loss (FSH, 169.7 +/- 124.2 mL; TSG, 172.7 +/- 151.5 mL) than was the use of smaller needles (PT-9; FSH, 58.8 +/- 66.3 mL; TSG, 34.1 +/- 25.6 mL; P =.036, P =.001, respectively). There were no postoperative strokes or bleeding complications in either group. No abnormalities were shown in either group by means of completion carotid duplex ultrasound scanning. CONCLUSION: FSH was equivalent, but not superior to, TSG in achieving hemostasis during carotid endarterectomy performed with ePTFE patch angioplasty. Adhesion properties of FSH to ePTFE are possibly different than those to native tissue and warrant additional investigation.

The incidence of heparin-induced antibodies in patients undergoing vascular surgery: a prospective study.

PURPOSE: This study prospectively assessed the incidence of heparin-induced antibodies in patients undergoing peripheral vascular surgery and determined whether the incidence is influenced by previous heparin exposure. METHODS: Fifty-four hospitalized patients (36 men and 18 women) undergoing peripheral vascular surgery and receiving intraoperative heparin anticoagulation were studied. Unfractionated porcine heparin was given for intraoperative anticoagulation and was not continued postoperatively. Carotid endarterectomy was performed in 36 patients, aortic reconstruction in 11 patients, and infrainguinal bypass in 7 patients. Plasma was tested before and after (14 +/- 7.5 [SD] days) surgery for IgG antibodies to the complex of heparin/platelet factor 4, using a standardized, validated enzyme-linked immunosorbent assay (ELISA). Results are expressed as an optical density ratio (ODR) of patient plasma to normal plasma, with the threshold for a positive result of > or = 1.8. Platelet counts and clinical outcomes were also assessed. RESULTS: The mean patient age was 67.2 +/- 9.7 years. A prior exposure to heparin was documented in 41% of patients. The mean intraoperative heparin dose was 9089 +/- 3607 units. Only 1 patient converted from a negative antibody status to a positive status (1.9%, 95% CI = 0.10%-11.18%). The change in the ELISA ODR after surgery was not significantly different for patients with (+0.042 +/- 0.272) and without (-0.022 +/- 0.299, P = 0.57) prior heparin exposure. Postoperatively, the platelet counts dropped from 227,620 +/- 78,308 microL, to 185,706 +/- 80,842 microL (P < .001). The decrease in platelet count was the same in patients with prior heparin exposure (-23.0 +/- 18.0%) and without (-18.0 +/- 14.0%, P = .46). One thrombotic complication occurred, a femorotibial bypass graft occlusion in a patient who tested negative for antibodies. CONCLUSION: Heparin-induced antibodies occur infrequently after peripheral vascular surgery. The commonly observed, mild degree of postoperative thrombocytopenia does not appear to be caused by heparin-induced antibodies. These results indicate that a standard dose of heparin for intraoperative anticoagulation during vascular surgery is not associated with a significant risk of heparin-induced thrombocytopenia and thrombosis.