Stanley O. Snyder

Long-term follow-up for recurrent stenosis: A prospective randomized study of expanded polytetrafluoroethylene patch angioplasty versus primary closure after carotid endarterectomy

PURPOSE To determine the effect of primary closure (PC) versus expanded polytetrafluoroethylene patch graft angioplasty (PGA) on the incidence of recurrent stenosis (> 50% lumen diameter narrowing) after carotid endarterectomy (CEA), 87 patients undergoing 100 consecutive CEA were prospectively randomized into two groups. METHODS Forty-four patients underwent 51 PC, and 43 patients underwent 49 PGA. All patients were evaluated after operation by duplex scanning at 1.5, 12, 24, and 36 months. There were no significant differences in the demographic characteristics or operative indications for CEA between the two patient groups. Complete follow-up was achieved in 86% (75/87) of the patients during the 36-month surveillance period. RESULTS The perioperative permanent neurologic morbidity in the PC and PGA groups was noted to be 4% and 2%, respectively (PC = 2/51 vs PGA = 1/49, p = 0.58). Three additional reversible cerebral ischemic events occurred in the postoperative period (PC = 2/51 vs PGA = 1/49, p = 0.58). Other morbidity included immediate postoperative hemorrhage requiring reexploration (1/51) in the PC group and an infected expanded polytetrafluoroethylene patch requiring removal and replacement with autogenous vein (1/49). Long-term follow-up detected a single patient with significant bilateral restenoses of his primarily closed carotid arteries. None of the patients in the PGA group had restenoses (PC = 2/51 vs 0/49, p = 0.50). In addition, no postoperative dilation of the common or internal carotid arteries or perioperative death was observed. CONCLUSIONS In patients undergoing CEA, these data demonstrate no significant difference in the perioperative morbidity or mortality between PC and PGA. Use of the patch did not engender patients to patch rupture or aneurysmal degeneration as previously described with vein patch angioplasty procedures. This series supports effective use of either technique to achieve minimal rates of restenosis.

Technical complications of endovascular abdominal aortic aneurysm repair

PURPOSE Results from 34 endovascular repairs of abdominal aortic aneurysms are reviewed to identify technical complications and relate them to anatomic and technical features of the operation. METHODS Twenty-one patients underwent attempted tube graft repair (mean follow-up, 13 months). Thirteen patients underwent placement of a bifurcated graft (mean follow-up, 7.2 months). RESULTS Twenty-five patients (74%) underwent repair without technical complication (16 tube graft and nine bifurcated graft). Of five patients who had tube graft complications, two involved small iliac arteries and resulted in arterial injury. One of these patients needed a femorofemoral bypass procedure, and the other required conversion to standard operation. Two patients had distal leaks associated with the attachment system, and one patient had misplacement of the distal attachment system. The two patients who had leaks were followed-up; one required operation after 7 months, whereas the other leak sealed. The patient who had distal attachment system misplacement had a second endograft placed within the first to provide a distal seal. The four patients who had bifurcated graft complications involved two graft limb stenoses, one managed with a Palmaz stent and the other with balloon angioplasty. The patient treated with balloon angioplasty had graft thrombosis 1 week after the operation, which resulted in the need for a femorofemoral bypass procedure. Another bifurcated graft patient had a graft limb twist, which has resulted in chronic claudication. One patient had placement of a limb too proximal in the common iliac artery with chronic leak, and an open operation was performed 18 months later. CONCLUSIONS Technical complications in this series seem to be associated with short distal necks, small iliac arteries, tortuous iliac arteries, and atherosclerosis at the aortic bifurcation. We believe that experience and understanding of these issues will reduce the risk of these complications in the future.

The use of composite grafts in femorocrural bypasses performed for limb salvage: A review of 108 consecutive cases and comparison with 57 in situ saphenous vein bypasses

We retrospectively reviewed the results of 108 consecutive femorocrural bypasses performed with prosthetic/autogenous composite graft material and compared these with the results of 57 crural bypasses using greater saphenous vein by the in situ technique. Indication for operation in all cases was the salvage of an otherwise imminently threatened limb. Polytetrafluoroethylene-composite grafts (n = 87) and human umbilical vein-composite grafts (n = 21) were placed only in patients lacking suitable autogenous material for in-line reconstruction. Patient groups were similar with respect to mean age, prevalence of arterial disease risk factors, quality of the distal runoff, and location of the distal anastomosis. Cumulative patency rates at 1 year by life-table analysis were 81.9%, 34.6%, and 12.1% for the in situ, polytetrafluoroethylene-composite and human umbilical vein-composite groups, respectively. At 2 years these were 63.9%, 29.9%, and 6.0%, respectively (p less than 0.025). Cumulative limb salvage at 1 year was 70.6%, 62.3%, and 32.7%, respectively. Wound-related complications occurred in 52.4% of human umbilical vein-composite, 38.6% of in situ, and 18.3% of polytetrafluoroethylene-composite bypasses (p less than 0.05). On the basis of these results, we conclude that femorocrural bypass with polytetrafluoroethylene-composite graft is an acceptable form of distal reconstruction for limb salvage in patients lacking sufficient lengths of autogenous vein. We no longer use human umbilical vein for composite construction.

Carotid involvement in aortic dissection diagnosed by duplex scanning

Symptomatic carotid dissection following repair of a proximal aortic arch dissection has been successfully diagnosed by noninvasive ultrasonic duplex scanning. Angiographic confirmation, follow-up examinations by duplex scanner, and conservative management with heparin anticoagulation and tight blood pressure control are discussed. The differing etiologies and potential neurologic complications following aortic root dissection vs. spontaneous cervical carotid dissection are considered with a review of the current literature. Although diagnosis can be achieved through arteriography, the combined modalities of duplex scanning allow evaluation of both anatomic and hemodynamic factors. Conservative therapy may prove the most appropriate mode of management in these neurologically unstable patients.

Arterialization of reversed autogenous vein grafts: Quantitative light and electron microscopy of canine jugular vein grafts harvested and implanted by standard or improved techniques***

To provide sequential, quantitative analysis of the cellular events occurring in reversed autogenous vein grafts after implantation and potential modifications of these events, two groups of veins were evaluated. Veins prepared by standard techniques of unmonitored pressure distension with cold heparinized saline solution, tributary ligation adjacent to the wall, and storage at 4 degrees C were morphometrically compared with veins harvested by means of a modified protocol of papaverine irrigation, tributary ligation away from the graft wall, pressure distension to 100 mm Hg with heparinized blood containing papaverine at body temperature, storage in identical solution at 4 degrees C, and implantation while distended. Unilateral jugular veins harvested from dogs with the modified technique (IRJV,N = 9) or standard technique (SRJV,N = 9) were implanted into carotid arteries, retrieved at 30 minutes, 2 days, and 10 days postoperatively along with the contralateral control vein after perfusion fixation in situ, and examined microscopically to quantitate intimal-medial thickness and endothelial damage (denudation and ultrastructural alterations). All IRJVs remained endothelialized, whereas SRJVs had 19% and 40% endothelial denudation at 30 minutes and 2 days, respectively, as well as massive neutrophil, platelet, and monocyte involvement. In contrast, IRJVs had only a modest infiltration of monocytes beginning early after implantation and culminating in their localization beneath endothelial cells; these endothelial cells increased in number during the 10-day period. Although SRJVs exhibited nearly complete reendothelialization over the luminal surface of macrophages by 10 days, endothelial damage was consistently higher than that of IRJVs at all periods and intimal-medial thickness was significantly greater at 10 days (65 +/- 0 vs. 57 +/- 0 micron, respectively; p less than 0.001). These findings suggest that endothelial preservation with improved harvesting techniques inhibits thrombosis and limits wall thickening and also that macrophages may play a protective role by promoting endothelial proliferation.

Duplex Scanning for the Intraoperative Assessment of Infrainguinal Arterial Reconstruction: A Useful Tool?

Duplex scan, arteriography, and graft flow rates were used intraoperatively to assess 56 infrainguinal arterial reconstructions for technical error. Intraoperative duplex scan identified a technical defect or low graft flow velocity in 22 of 56 (39%) grafts. Eleven of the defects were judged to be clinically significant and were corrected. Four of these defects were missed by the completion arteriogram. One technical defect identified by completion arteriography was missed by duplex scan. Fifty percent (5/10) of grafts with an abnormal intraoperative duplex scan which were not corrected occluded within 30 days. Graft flow rates measured by the electromagnetic flowmeter were neither predictive of technical defect nor early graft outcome. Although the sensitivity of arteriography and duplex scan (88% sensitivity for both) were both high for predicting early graft occlusion, the combination of duplex scan and completion arteriography was significantly more accurate (p<.0001) in predicting early graft outcome than either study alone. Duplex scan identified significant graft defects which were not detected by completion arteriography or graft flow rate measurement. The duplex scan also provided hemodynamic information which was predictive of early graft outcome. The duplex scan can be an important adjunct to completion arteriography for the intraoperative assessment of infrainguinal arterial reconstruction.

The Kensey catheter: Preliminary results with a transluminal atherectomy tool

The Kensey dynamic angioplasty instrument is an atherectomy device approved by the Food and Drug Administration that uses a rotating cam tip housed within a flexible polyurethane catheter to recanalize obstructed and stenotic arteries. Twenty patients with significant femoral arteriosclerotic occlusive disease underwent attempted transluminal endarterectomy of 23 extremities with the Kensey catheter. Significant improvements of superficial femoral artery luminal diameter was achieved in 10 of 13 patients with stenosis and passage of the spinning catheter tip at 60,000 to 90,000 rpm through areas of complete occlusion was successful in 4 of 10 cases. Balloon dilatation was used as an adjunct to increase the diameter of the superficial femoral artery lumen in 11 of 14 successful cases. This preliminary report provides technical data and short-term follow-up of this new innovative vascular tool.

Vein Harvest Ischemia: A Peripheral Vascular Complication of Coronary Artery Bypass Grafting

Lower-extremity ischemia can lead to impaired healing of saphenous vein excision sites in patients with significant peripheral vascular disease (PVD). Five patients who required infrainguinal revascularization for wound necrosis of the harvest site after coronary artery bypass grafting are described. The male/female ratio was 2:3 with a mean age of 67 (range 45-87) years. The most commonly associated problems were insulin-dependent diabetes mellitus (80%) and congestive heart failure (60%). The saphenous vein was harvested from the thigh and leg in three patients and exclusively from the leg in the others. Manifestations of ischemia ranged from persistent ulceration to complete wound disruption threatening limb loss. Impaired healing was isolated to infragenicular wounds in all patients. Pedal pulses were not detected in any of the affected extremities. Determination of the ankle/brachial pressure indices (ABI) revealed values of < 0.5 in three affected limbs. Non-compressible vessels resulted in falsely raised ABI of > 1.0 in the remaining two limbs; however, Doppler waveform analysis in these patients demonstrated significant PVD. Aggressive wound care and antibiotic therapy were continued for mean of 9 weeks before operative intervention. Infrainguinal reconstruction included femoropopliteal (two), femorotibial (two) and popliteal-tibial bypass (one). Autologous arm and saphenous veins in addition to expanded polytetrafluoroethylene grafts were used effectively. Limb salvage and wound healing were achieved in 100% of the patients without untoward sequelae. It is concluded that unrecognized PVD in patients undergoing coronary artery bypass grafting can lead to significant morbidity. Patients at risk may be identified with a combination of history, physical examination and non-invasive testing. In limbs with ABI < 0.5 or significantly abnormal Doppler-derived waveforms, alternate sites of vein harvesting should be sought. Nonetheless, once wound necrosis develops as a result of vascular insufficiency, this study supports lower-extremity revascularization to achieve healing and limb salvage.

Angioscopic Evaluation of Valvular Disruption During In Situ Saphenous Vein Bypass

Several valvulotomes are currently available to achieve valvular disruption; however, studies comparing the efficacy of these endoluminal instruments are lacking. This prospective study evaluates the efficacy and safety of the three most commonly employed valve cutters: the Hall, LeMaitre, and Mills valvulotomes. A total of 30 in situ greater saphenous vein bypass grafts were included in this investigation. Valvular disruption was attempted with either the LeMaitre (11 cases), Hall (12 cases), or Mills (7 cases) valvulotomes. Subsequently, angioscopy was employed to assess the completeness of valvulotomy and to identify vein wall injury. Incomplete disruption of one or more valve complexes was identified in 2 of 12 (17%) grafts in the Hall group, 10 of 11 (91%) grafts in the LeMaitre group, and 0 of 7 grafts in the Mills group (p <0.01). Intact valve cusps were noted in 2 of 36 (5.5%) valves, 31 of 42 (74%) valves, and 0 of 38 valves after valvulotomy with the Hall, LeMaitre, and Mills instruments, respectively (p <0.01). A total of three valvulotome-related injuries occurred; two injuries were noted in conjunction with the Hall instrument, one was associated with the Mills valvulotome, and no injuries were detected after use of the LeMaitre instrument (p=0.33). These data demonstrated a significantly increased incidence of retained valve cusps when the LeMaitre valvulotome was used. No significant difference in the rate of vein wall injury was noted in the three groups. Thus this study suggests that the LeMaitre instrument is not as effective as either the Hall or Mills valvulotomes for achieving valvular disruption.

Successful management of traumatic false aneurysm of the extracranial vertebral artery by duplex-directed manual occlusion: A case report

A 32-year-old man was transferred to our hospital after a 2.0 by 2.5 cm traumatic false aneurysm of the distal extracranial vertebral artery was noted after a stab wound of the posterior side of the neck. To obviate the need for operative exposure of the distal vertebral artery at the base of the skull, we elected to perform duplex-directed manual occlusion of the lesion. Angiography before and after the procedure, as well as 10-month follow-up duplex ultrasonography, demonstrated satisfactory thrombosis of the false aneurysm without evidence of a residual arterial defect. There was no morbidity associated with the procedure. We conclude that duplex-directed manual occlusion, a new technique recently described for the nonoperative management of postcatheterization femoral false aneurysms, can be applied safely and effectively to false aneurysms in other locations in which the risks and technical difficulties of operative repair render surgery less desirable.