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Purpose: To determine if a complete intra-arterial environment affects endothelialization rate and basement membrane organization in polytetrafluoroethylene (PTFE) grafts., Method: Thirty dogs underwent either infrarenal abdominal aorta PTFE interposition (12) or intraluminal stented (18) grafting. Grafts were explanted at 4 and 8 weeks and rate of endothelial ingrowth calculated. Endothelial cells were identified and basement membrane organization assessed using antibodies against endothelial cell-specific surface antigen CD31, type IV collagen, and laminin., Results: Endothelialization rates, expressed as percent graft surface area coverage per week, were 3.7% +/- 0.62% (4-week control), 12.9% +/- 0.58% (4-week stented), 4.2% +/- 0.62% (8-week control), and 10.0% +/- 0.54% per week (8-week stented grafts). Endothelial repaving rates were constant for control and increased in all stented grafts (P <0.01). At 4 weeks, laminin was identified in all control (6 of 6) and no stented grafts. Staining was confined to the 20% of the hyperplastic intimal area immediately below the endothelium. At 4 weeks, type IV collagen was present throughout the entire hyperplastic intima in control specimens but was confined to a discrete subendothelial zone in stented grafts. By 8 weeks, type IV collagen became concentrated in the luminal one third of the intima in control grafts., Conclusion: Intra-arterial graft location is associated with early formation of an organized basement membrane and accelerated endothelialization in PTFE grafts.

Purpose: To investigate the effect of stent design and deployment mechanism on endoluminal graft healing., Method: Twenty dogs underwent infrarenal abdominal aorta polytetrafluoroethylene (PTFE) interposition (6) or intraluminal stented grafting using either a balloon expandable (BE, n = 8) or self-expanding (SE, n = 6) stent design. Grafts were removed at 8 weeks. Length of endothelial ingrowth and intima to media height ratios (IMHR) were calculated. Perianastomotic smooth muscle (Actin+), macrophage (CD44+), proliferating (PCNA+), and platelet-derived growth factor (PDGF+) cell content were determined., Results: Mean endothelial ingrowth was 1.10 +/- 0.15 cm (control), 1.88 +/- 0.13 cm (BESG), and 2.16 +/- 0.18 cm (SESG) proximally; and 0.94 +/- 0.12, 2.11 +/- 0.11 cm, and 2.16 +/- 0.15 cm, respectively, at the distal anastomosis. Endothelial ingrowth was greater in all stented grafts (P <0.001). Mean IMHRs were 1.42 +/- 0.16 (control), 0.50 +/- 0.14 (BESG), and 0.77 +/- 0.2 (SESG) proximally; and 0.84 +/- 0.1, 0.42 +/- 0.09, and 0.77 +/- 0.12 (SESG) distally. Lower IMHRs were observed in all stented graft regions (P <0.05) except the distal anastomosis of SESG. The PDGF+ and PCNA+ cell content was decreased, and Actin+ cell content was increased in all stented grafts (P <0.05)., Conclusion: Intraluminal location enhances endothelialization and attenuates intimal thickening in PTFE grafts. The enhanced healing of intraluminal stented grafts is irrespective of the type of stent or deployment mechanism used.

Purpose: To investigate the effect of anesthetic technique on cardiac morbidity after carotid artery surgery., Patients and Methods: From 1991 to 1994, 266 consecutive carotid endarterectomies were performed under local/regional (n=140) or general anesthesia (n=126). The effects of anesthetic technique on postoperative adverse cardiac events were assessed retrospectively., Results: Preoperative cardiac testing was performed in all patients undergoing general or local/regional anesthesia. Medical characteristics were similar among patients in both groups. Forty-seven adverse cardiac events (4 myocardial infarction, 9 congestive heart failure, 7 angina, and 27 new ventricular dysrhythmias) occurred postoperatively in 38 patients (14.3%). There were no deaths. The relative risks of general anesthesia for dysrhythmias, myocardial infarction, angina, congestive heart failure, and total adverse cardiac events were 2.22, 0.37, 0.83, 1.38, and 1.5, respectively. The only statistically significant differential was the increased risk of postoperative dysrhythmias after general anesthesia (P<0.03)., Conclusions: Major cardiac morbidity following carotid endarterectomy is independent of anesthetic technique.