Faculty Bibliography

BACKGROUND: Prosthetic grafts for lower-extremity bypass have limited patency compared with autologous vein grafts. Precuffed expanded polytetrafluoroethylene (ePTFE) grafts alter the geometry of the distal hood to improve patency. This study reports the authors' long-term results on the use of precuffed ePTFE grafts for infrainguinal bypasses in patients with arterial occlusive disease and compares these with results of reversed great saphenous vein grafts (rSVG). METHODS: A retrospective review of billing codes identified 101 polytetrafluoroethylene (PTFE) and 47 rSVG bypasses performed over a 6-year period. Femoral to below-knee popliteal and femoral to tibial bypasses were analyzed. Data collected consisted of risk factors, Rutherford classification, bypass inflow and outflow, runoff vessels, patency, amputation, and death. Primary end points consisted of primary, assisted-primary, and secondary patency along with limb salvage. RESULTS: Mean age of the patients was 76 years in the PTFE group and 69.8 years in the rSVG group. For femoral to below-knee popliteal bypasses, primary patency at 1, 3, and 5 years in the PTFE group was 76.9%, 48.7%, and 43.3%, respectively, compared with 77.1%, 77.1%, and 77.1%, respectively, in the rSVG group (P = 0.225). Secondary patency was 89.2%, 70.9%, and 50.6% in the PTFE group compared with 84.4%, 84.4%, and 84.4% in the rSVG group (P = 0.269). Limb salvage was similar in the PTFE compared with the rSVG group (97.7%, 90.5%, and 79.4% vs. 83.3%, 83.3%, and 83.3%; P = 0.653). For femoral to tibial bypasses, primary patency in the PTFE group at 1, 3, and 5 years was 57.1%, 40.4%, and 22.1%, respectively, compared with 67.4%, 67.4%, and 50.6%, respectively, for the rSVG group (P = 0.246). Secondary patency was 75.5%, 44.9%, and 22.7% in the PTFE group compared with 91.8%, 91.8%, and 52.5% in the rSVG group (P = 0.022). Limb salvage at 1, 3, and 5 years was 79.2%, 55.7%, and 55.7%, respectively, in the PTFE group compared with 96.4%, 96.4%, and 64.3%, respectively, in the rSVG group (P = 0.046). CONCLUSIONS: Precuffed ePTFE grafts demonstrate similar 1-year patency to that of rSVG. However, mid- and long-term patency is reduced compared with saphenous vein grafts (SVG), especially to tibial targets. PTFE grafts to the popliteal demonstrate limb salvage rates similar to those of SVG. In the tibial vessels, limb salvage rates for PTFE grafts are significantly worse compared with SVG.

Endovascular aneurysm repair is being used increasingly to treat ruptured abdominal aortic aneurysms (RAAAs). Approximately 25% of RAAAs undergo complete circulatory collapse before or during the procedure. Patient survival depends on obtaining and maintaining supraceliac balloon control until the endograft is fully deployed. This is accomplished with a sheath-supported compliant balloon inserted via the groin contralateral to the side to be used for insertion of the endograft main body. After the main body is fully deployed, a second balloon is placed within the endograft, and the first balloon is removed so that extension limbs can be placed in the contralateral side. A third balloon can be placed via the contralateral side and ipsilateral extensions deployed as necessary. This technique of supraceliac balloon control is important to achieving good outcomes with RAAAs. In addition to minimizing blood loss, this technique minimizes visceral ischemia and maintains aortic control until the aneurysm rupture site is fully excluded.

Endovascular repair of ruptured abdominal aortic aneurysms seems to have better outcomes than open repair if certain strategies, techniques, and adjuncts are employed. These include a standard approach or protocol; use of fluid restriction (hypotensive hemostasis), performance of the procedure in a site equipped for excellent fluoroscopic imaging and open surgery, use of percutaneous approaches and local anesthesia for initial guide wire and catheter placement, placement of a large supraceliac aortic sheath, and obtaining balloon control only when absolutely necessary. Details of obtaining this control are critical, and aortic control must not be lost until the rupture site is excluded. Multiple balloons might be required, including ones placed within the endograft. Sheath placement and fixation until the balloon is removed are also critically important. Bifurcated and unilateral endografts can be used successfully. Abdominal compartment syndrome must be looked for and treated aggressively; endovascular repair must be used in the highest-risk patients, including those in profound hemorrhagic shock, to gain the greatest advantages of this approach.

OBJECTIVE: This study reviews a single-center experience of endovascular popliteal aneurysm (PAA) repair. METHODS: A retrospective review was performed to identify all endovascular PAA repairs performed between September 2004 and January 2011. RESULTS: We identified 21 patients (mean age, 74 +/- 9 years, 91% men) with PAAs (mean size, 2.89 +/- 1.0 cm) in 26 limbs, of which 38% were symptomatic. All patients underwent endovascular repair with a Viabahn covered stent graft (W. L. Gore & Assoc, Inc, Flagstaff, Ariz). Postoperatively, all patients were maintained on antiplatelet therapy with clopidogrel or aspirin, or both. Mean follow-up was 22 +/- 17 months (range, 1-57 months). One patient with one aneurysm was lost to follow-up. Primary and secondary patencies were both 91.2% at 1 year and were 85.5% and 91.2%, respectively, at 2 years. The limb salvage rate was 100%. Four stent graft failures occurred at a mean of 12.3 +/- 11 months. One technical failure due to stent graft infolding required conversion to an open femoral-popliteal bypass. Three additional graft failures occurred in patients with poor (single-vessel) runoff. Compared with patients with two- or three-vessel runoff, the graft failure rate in patients with single-vessel runoff was statistically significant (P = .02). Two of the graft failures were successfully treated with open thrombectomy, and one required a tibial artery bypass for limb salvage. CONCLUSIONS: Endovascular repair of PAAs is feasible and has acceptable midterm patency rates. Poor distal runoff predicted graft failure.

INTRODUCTION:: Iatrogenic arterial injury is an uncommon but recognized complication of posterior spinal surgery. The spectrum of injuries includes vessel perforation leading to hemorrhage, delayed pseudoaneurysm formation, and threatened perforation by screw impingement on arterial vessels. Repair of these injuries traditionally involved open direct vessel repair or graft placement, which can be associated with significant morbidity. METHODS:: We identified five cases of iatrogenic arterial injury during or after posterior spinal surgery between July 2004 and August 2009 and describe the endovascular treatment of these five patients. RESULTS:: In two patients, intraoperative arterial bleeding was encountered during posterior spinal surgery. The posterior wounds were packed, temporarily closed, and the patients were placed supine. Angiography in both patients demonstrated arterial injury necessitating repair. Covered stent grafts were deployed through femoral cutdowns to exclude the areas of injury. In three additional patients, postoperative computed tomography imaging demonstrated pedicle screws abutting or penetrating the thoracic or abdominal aorta. In all three patients, angiography or intravascular ultrasound (IVUS), or both, confirmed indention or perforation of the aorta by the screw. Aortic stent graft cuffs were deployed through femoral cutdowns to cover the area of aortic contact before hardware removal. All five patients did well and were discharged home in good condition. CONCLUSIONS:: Endovascular repair of arterial injuries occurring during posterior spine procedures is feasible and can offer a safe and less invasive alternative to open repair

Background: The treatment of venous insufficiency using endovenous laser ablation or radiofrequency ablation may result in endothermal heat induced thrombosis (EHIT), a form of deep venous thrombosis. This study sought to assess the effect of ablation distance peripheral to the deep venous system on the incidence of EHIT. Methods: This study was a retrospective review of a prospectively maintained database from 4/2007 to 7/2011. Consecutive patients undergoing great saphenous vein (GSV) or small saphenous vein (SSV) ablation were evaluated. Previous to 2/2011, all venous ablations were performed 2cm peripheral to the saphenofemoral or saphenopopliteal junctions (Group I). Subsequent to 2/2011, ablations were performed 2.5cm peripheral to the respective deep system junctions (Group II). The primary outcome was the development of EHIT II or greater, i.e. thrombus protruding into the deep venous system. Secondary outcomes included procedure-site complications such as hematomas and saphenous nerve injury. Chi-square tests were performed for all discrete variables, and unpaired Students t-tests were performed for all continuous variables. P<.05 was considered statistically significant. Results: A total of 3,526 procedures were performed, Group I (N=2672) and Group II (N=854). General demographics and CEAP classification did not differ significantly between the two groups. EHIT demonstrated a trend towards diminished frequency in Group II (Group I: 2.8% vs Group II: 1.6%, P=.077). There were no reported cases of EHIT III or IV in this patient cohort. Patients in Group I were treated using anticoagulation 56% of the time, and patients in Group II were treated using anticoagulation 100% of the time. The frequency of procedure site complications was low and did not differ significantly between the two groups. Conclusions: This study suggests that changing the treatment distance from 2cm to 2.5cm peripheral to the deep venous junction may result in a diminished incidence of EHIT. Ongoing evaluation is required to validate these results and to reaffirm the durability of the technique