Anthony Cassano

The Persistence of Electrostatically Seeded Endothelial Cells Lining a Small Diameter Expanded Polytetrafluoroethylene Vascular Graft

Purpose: The purpose of this study was to evaluate the persistence of electrostatically seeded endothelial cells (ECs) lining an expanded polytetrafluorethylene (e-PTFE) graft after one week exposure to in vivo circulation in a canine femoral artery bypass model. This was accomplished by visualizing the PKH 26 (red fluorescent) label placed in the EC membranes prior to the seeding procedure. Furthermore, this study was performed to confirm that thesourceof the ECs lining thegraft werethosefrom theinitial inoculum. Methods: This evaluation consisted of harvesting autologous, canine jugular vein ECs, PKH 26 labeling of the ECs, electrostatic EC seeding the e-PTFE grafts (4 mm GORE-TEX®, Length = 6 cm), implanting thegrafts (femoral artery model) for one week, and explanting the grafts for light, fluorescent and scanning electron microscopy evaluations of the luminal surface. Results: The unseeded grafts (controls) had a mean fluorescence surface coverage of 6.82 ± 7.19%, while the EC seeded grafts had a mean of 90.3 ± 14.3% which is significantly (p<0.001) different from the controls. Overall, the seeding timeincluding the EC harvesting and PKH 26 labeling protocol was approximately 75 min. Conclusions: The electrostatically seeded ECs persisted after implantation of the graft as demonstrated by the PKH 26 labeling data. The fluorescent data also demonstrated that the neointima formed (EC luminal surface coverage) one week after implantation was in fact derived from the ECs initially seeded as determined by the abundance of the labeled ECs.

Endothelial cell seeding of a 4-mm I.D. Polyurethane vascular graft

We evaluated the extent (luminal coverage) of the endothelial cell (EC) lining/neointimal development and the thromboresistance of electrostatically EC seeded small diameter Chrono Flex-polyurethane vascular grafts. The evaluation consisted of harvesting autologous, canine jugular vein ECs, electrostatically seeding the polyurethane grafts (4-mm I.D., length = 6 cm) with the harvested ECs, implanting the grafts in a canine femoral artery model for four to six weeks, and excising the grafts for histological and scanning electron microscopy evaluations. Results of the histological evaluation (mid-graft region only) indicated that electrostatic EC seeding led to neointimal development and to minimal to no thrombus formation within the EC seeded grafts. The unseeded control grafts resulted in no neointimal development and substantial thrombus formation on the graft luminal surfaces. Scanning electron microscopy examination demonstrated a mature, confluent endothelium with a ‘‘cobblestone’’ appearance on the EC seeded graft luminal surface after six weeks. We conclude that electrostatic EC seeding enhanced the development of a neointima and reduced the incidence of thrombosis in polyurethane grafts implanted in a canine femoral artery model.

Evaluation of electrostatically endothelial cell seeded expanded polytetrafluoroethylene grafts in a canine femoral artery model.

(1) Purpose: The purpose of this study was to evaluate the extent (luminal coverage) of the endothelial cell (EC) lining/neointimal development and the thromboresistance of electrostatically EC seeded small diameter e-PTFE vascular grafts. (2) Methods: This evaluation consisted of harvesting autologous, canine jugular vein ECs, electrostatically EC seeding the e-PTFE grafts (4 mm GORE-TEX,® Length = 6 cm), implanting the grafts in a canine femoral artery model for six weeks, and excising the graft for histological and scanning electron microscopy evaluations. (3) Results: The results of the histological evaluation (mid-graft region only) indicated that the electrostatic EC seeding significantly affected neointimal development (p<0.01) and the degree of thrombus formation (p<0.001) within the EC seeded grafts versus the untreated control grafts. Scanning electron microscopy examination demonstrated a mature, confluent endothelium with a “cobblestone” appearance on the EC seeded graft luminal surface. The control grafts demonstrated an equal distribution of SMCs through the graft wall while the electrostatically EC seeded graft sections exhibited an uneven SMC cellular distribution which was skewed toward the graft luminal surface. (4) Conclusions: The presence of electrostatic EC seeding significantly (p<0.01) enhanced the development of a neointima and reduced the incidence of thrombosis in e-PTFE grafts implanted in a canine femoral artery model. Results of the mid-graft SMC migration measurements indicate that the electrostatic EC seeding had a significant (p<0.001) impact on the acute healing of the standard wall e-PTFE vascular graft specimens.

Stellate ganglion blockade and bilateral cardiac sympathetic denervation in patients with life‐threatening ventricular arrhythmias

Autonomic modulation is being increasingly employed as a strategy to treat ventricular arrhythmias refractory to beta‐blockers, antiarrhythmic drugs, and catheter‐based ablation procedures. We report 6 patients with refractory ventricular tachycardia (VT) or ventricular fibrillation (VF) treated with stellate ganglion blockade (SGB) and/or bilateral cardiac sympathetic denervation (CSD). Our case series emphasizes the concept that the cardiac sympathetic nerves are important targets in the management of ventricular arrhythmias. SGB and CSD can be effective in suppressing VT/VF and can be offered to patients with refractory ventricular arrhythmias as an adjunct to conventional therapy.