Postoperative predictive value of a new method of intraoperative angiographic assessment of runoff in femoropopliteal bypass grafting

In 96 consecutive patients undergoing primary femoropopliteal bypass grafting, the runoff was evaluated with a new grading system, based on findings at intraoperative postreconstruction serial angiography. This concept, which takes foot vessel involvement into account in patients with only one patent crural artery, is a modification of the traditional method of runoff assessment. Good runoff was defined as patency of two or three lower leg arteries to the foot or one patent, vessel continuous with intact anterior or posterior foot arch. In limbs with no patent vessel or one patent vessel with deficient or occluded foot arches, the runoff was classified as poor. The cumulative primary patency rates at 12 months in groups with good and poor runoff were 81% and 37%, respectively. The predictive value of the new method was superior to that of other comparable methods (traditional method, Society for Vascular Surgery and International Society for Cardiovascular Surgery criteria, and modified Society for Vascular Surgery and International Society for Cardiovascular Surgery criteria). This improved prediction can be ascribed to the optimal angiographic technique for visualizing distal vessels, selective evaluation of foot vessel runoff with a new concept, and the criteria used to define good and poor runoff.     

Correlation between Angiographic Runoff and Intraoperative Hydraulic Impedance with Regard to Graft Patency

The aim of this study was to evaluate the correlation between peripheral runoff estimated by the SVS/ISCVS scoring system and intraoperatively measured outflow. Sixty-six patients received 27 femoropopliteal and 39 femorocrural ePTFE grafts. During the operation, peripheral resistance and hydraulic impedance were measured by means of the extracorporeal-bypass-flow method. Angiographic runoff was estimated according to the revised SVS/ISCVS system. Patients were entered in a graft surveillance program and patency was calculated after 3 years. The relation between the angiographic runoff score and graft patency as well as correlations between hemodynamic data, peripheral resistance, and hydraulic impedance were calculated. Primary and secondary patency rates for femoropopliteal grafts were 44% and 60% and those for femorocrural bypasses were 35% and 45%. Mean angiographic vessel diameters for above-knee and below-knee popliteal arteries were 0.51 ± 0.02 mm and 0.47 ± 0.04 mm. Diameters of crural arteries were 0.34 ± 0.03 mm (posterior tibial artery), 0.27 ± 0.02 mm (anterior tibial artery) and 0.26 ± 0.21 mm (peroneal artery). The differences in diameter between popliteal and crural grafts were statistically significant (p < 0.01). Calculated correlations between the preoperative score and hemodynamic, resistance, and impedance values or patency rates were generally poor and statistically not significant. A statistical significant correlation was found only between SVS/ISCVS score and recipient vessel diameters. The angiographic runoff did not correlate with peripheral resistance, impedance, or patency rates. Patients with angiographically poor outflow should additionally be evaluated with duplex sonography or magnetic resonance angiography and should not be denied peripheral reconstructions.     

Angiographic criteria for prediction of early graft failure of secondary infrainguinal bypass surgery

Complete intraoperative postreconstruction angiograms were obtained during 93 reoperations after failed femoropopliteal and femorodistal bypass grafts to evaluate the predictive value of a new method of angiographic runoff assessment. Good runoff was defined as patency of two or three lower leg arteries to the foot, or one patent vessel continuous with an intact anterior or posterior foot arch in femoropopliteal and proximal femorodistal bypasses, and integrity of both arches in low femorodistal bypasses. All other outflow patterns were considered poor. The cumulative 1-year patency rate was 61% with a 79% limb salvage rate after reoperations performed in limbs with good runoff. In reoperations with poor runoff, the patency rate was only 5% with a 22% limb salvage rate. In reoperations with good runoff, and 85% patency rate of vein grafts compared to 43% of prosthetic grafts clearly demonstrated the importance of graft material on early outcome. The improved prediction of early outcome with this new method of angiographic runoff evaluation might allow more rational management of patients with failed infrainguinal grafts.     

Angioplasty of the distal anastomosis und runoff arteries of occluded infrainguinal bypasses

BACKGROUND: We investigated the clinical results of transluminal angioplasty performed through infrainguinal bypass grafts for stenotic or occlusive lesions at the distal anastomosis and/or in the runoff arteries in high risk patients and the influence of different parameters on limb salvage, primary and secondary patency rate. PATIENTS AND METHODS: Between January 2001 and March 2005 we performed 49 transluminal angioplasties on stenotic or occlusive lesions at the distal anastomosis and/or in the runoff arteries in 49 (16 female, 23 male, mean age 71.1 years) patients with occluded infrainguinal bypass. 20 angioplasties occurred in the runoff arteries, 5 at the distal anastomosis and 24 at both locations at a median of 11.3 months (range 2-85 months) after infrainguinal bypass grafting). 20 procedures were on popliteal artery above the knee, 21 below the knee and 8 on crural arteries. RESULTS: Kaplan-Meier analysis showed a cumulative limb salvage of 87.6 and 76.4 % after 6 months and two years, respectively. Patients with gangrenous lesions had a 5 times higher risk of amputation (Cox-regression model). Primary and secondary patency rates were at 6 months 85.1 and 91.1 % respectively and were at one year 73.3 and 78.8 % respectively. Patients with end stage renal disease were in 4 times hazard to primary occlusion and patients with gangrenous lesions 5 times to secondary occlusion (Cox-regression model). CONCLUSION: Even if the long-term results of angioplasty on stenotic or occluded lesions at the distal anastomosis and/or in the runoff arteries are inferior to the results of surgical revisions reported in literature, angioplasty in high risk patients with absence af a vein may be the first line alternative intervention for limb salvage.     

Composite sequential grafts for femorocrural bypass reconstruction: experience with a modified technique

BACKGROUND: To evaluate the efficacy of a modification of the composite sequential femorocrural bypass graft that we adopted in 1985, a retrospective case-note study was undertaken. The grafts combined a prosthetic femoropopliteal section with a popliteal to crural section with autologous vein, linked via a common intermediate anastomosis sited on the above-knee popliteal artery. PATIENTS AND METHODS: Between 1985 and 2000, 68 grafts of this type were constructed in 65 patients with critical ischemia of the lower limb and insufficient autologous vein for construction of an all venous bypass. Reasons for insufficient long saphenous vein included previous lower limb bypass in 33 cases, phlebitis in 16 cases, venous hypoplasia in eight cases, and previous varicose vein surgery in seven cases. Distal anastomoses were carried out to the peroneal artery in 26 cases, the anterior tibial artery in 17 cases, the posterior tibial artery in 17 cases, and the pedal arteries in eight cases. Sources of vein included the long saphenous vein in 26 cases, the arm vein in 38 cases, and the short saphenous vein in two cases. In 22 limbs (32%), angiography had shown an occluded segment of above-knee popliteal artery, and in these cases, local popliteal disobliteration was performed to receive the composite anastomosis and to provide additional outflow. RESULTS: The 2-year cumulative primary patency, secondary patency, and limb salvage rates were 68%, 73%, and 75%, respectively. Localized popliteal disobliteration did not compromise graft patency (P =.07, with log-rank test). CONCLUSION: In the absence of sufficient autologous vein, patients needing bypass to crural arteries can be offered reconstruction with composite sequential grafting with satisfactory results. Furthermore, an occluded above-knee popliteal segment is not a contraindication for composite sequential bypass reconstruction.     

Operative Repair of Popliteal Aneurysms: Effect of Factors Related to the Bypass Procedure on Outcome

The objective of this study was to compare patency rates following the repair of popliteal aneurysms according to the site of inflow, material of bypass graft and quality of distal runoff. Seventy bypasses were performed over an 11-year period. Autogenous saphenous vein was used in 53 procedures (75.7%) and prosthetic material was used in 17 (24.3%). Early mortality was 2.8%. Early primary and secondary patency rates were 95.7% and 97.1%, respectively. Autogenous vein showed better 10-year patency than prosthetic material (86% vs. 57%; p = 0.02). No significant differences in patency were observed according to the inflow site (87.8% groin vs. 74.7% supragenicular). Bypasses that originated in the groin showed improved patency when a saphenous vein was used (84.8% vs. 43.7%; p = 0.01). However, no influence of the graft material was noted in supragenicular bypasses (90.4% vs. 84.8%; p = 0.6). Bypasses in extremities with good runoff showed better patency than those in limbs showing poor runoff (86% vs. 55%; p = 0.003). The use of saphenous vein for the repair of popliteal aneurysms showed better results than those with prosthetic material, although in bypasses originating from the distal superficial femoral or above-knee popliteal artery, no significant differences in patency were observed. Good distal runoff was associated with improved overall outcome.     

Pedal Bypass for Limb Salvage

Background: Pedal bypass grafting is often the only method of limb salvage in patients with chronic critical lower limb ischemia due to atherosclerotic obliteration of the crural arteries, including patients with diabetic foot gangrene. It involves arterial reconstruction with distal anastomosis to one of the pedal arteries.

Material and Methods: Between January 2000 and June 2004, 54 pedal bypasses were performed in 53 patients with chronic critical lower limb ischemia. Forty-seven (87%) patients had gangrene or ischemic ulcer, 36 (68%) had diabetes. In some of the patients (16.7%), previous percutaneous transluminal angioplasty (PTA) of the crural arteries had failed. Preoperative angiographic findings were unsatisfactory in the majority of the patients; the plantar arch was not visualized in 36 (66.7%) limbs.

Results: In the period investigated (54 months) 11 grafts (20.4%) failed. Early thrombectomy resulting in long-term graft patency salvaged five limbs. One limb with graft occlusion occurring after foot ulcer healing was also salvaged. However, one amputation had to be performed despite a patent graft. The perioperative mortality rate was 3.8%. Cumulative primary and secondary graft patency rates and limb-salvage rates at 54 months were 76%, 78% and 81%, respectively.

Conclusion: Pedal bypass grafting is a safe method with very good long-term outcomes. The absence of the pedal arteries or plantar arch on preoperative angiograms need not be taken as a contraindication to pedal vascular reconstruction. In discussions on the plantar arch it is recommended to discriminate between its actual absence and a mere “angiographic” absence.     

Small popliteal artery aneurysms: are they clinically significant?

OBJECTIVE: We undertook this study to determine whether popliteal artery aneurysm diameter correlates with initial symptoms and presence of associated occlusive disease. METHODS: Duplex arteriography before infrainguinal revascularization in 500 lower extremities enabled diagnosis of 34 popliteal aneurysms in 25 patients (24 male, 1 female) over the last 4 years. Fourteen patients (41%) had no symptoms (group 1) and 20 (59%) had symptoms (group 2) of severe claudication (n = 8), acute ischemia (n = 6), rest pain (n = 2), and tissue loss (n = 4). We compared clinical presentation with popliteal artery diameter, prevalence of thrombosis, and presence of associated occlusive disease. RESULTS: Popliteal artery aneurysm diameter averaged 2.8 +/- 0.7 cm (range, 1.8-4.5 cm) in group 1 and 2.2 +/- 0.8 cm (range, 1.3-4.0 cm) in group 2 (P <.03). Popliteal aneurysm thrombosis was present in 7 of 20 limbs in group 2. Four of these patients also had ipsilateral superficial femoral artery thrombosis. Evaluation of the infrapopliteal arteries in group 1 showed three-vessel runoff in 7 limbs, two-vessel runoff in 3 limbs, one-vessel runoff in 2 limbs, and no vessel runoff in 2 limbs. However, all infrapopliteal arteries were either occluded or significantly stenotic in 14 limbs (70%). In group 2, one-vessel runoff was observed in 5 limbs, and two-vessel runoff in 1 limb. CONCLUSIONS: Smaller popliteal artery aneurysm was associated with higher incidence of thrombosis, clinical symptoms, and distal occlusive disease. Liberal use of duplex scanning in this setting may have accounted for the increased awareness that small popliteal artery aneurysms can thrombose and present with severe ischemia.     

Natural history of above- and below-knee femoropopliteal grafts

Postoperative physiologic data were reviewed in 74 patients with 85 femoropopliteal bypass grafts. Documented progression of atherosclerosis occurred in the aortoiliac segment in 18 limbs and in the popliteal and tibioperoneal vessels in 14 limbs, although aortoiliac disease was more often responsible for graft failure. Grafts with good postoperative runoff as determined by hemodynamic measurements had a statistically significant higher patency rate than those with poor runoff. Nearly half of the limbs with a progressive postoperative decline in the ankle-arm index ultimately had graft occlusion. Rapid progression of popliteal artery atherosclerosis distal to an above-knee graft was not a significant problem.     

Short distal origin vein graft in diabetic foot syndrome

PURPOSE: World wide increase of diabetes compound with diabetic foot syndrome becomes a challenge in vascular surgery to avoid limb loss. In diabetics a special pattern of atherosclerosis is prevalent with disease limited to the infrageniculate arteries but sparing inflow vessels and distal tibial and pedal arteries. This provides short bypass grafting from popliteal to tibial and pedal arteries, a concept first described by F. Veith in 1981. METHODS: Diabetics with severe atherosclerotic disease and limb-threatening ischemia got general evaluation and vascular imaging. Falling in this special category the patients underwent short vein bypass grafting originating at the first or third popliteal segment extending to the tibial or pedal arteries. Follow up of patency and limb salvage was nearly complete. RESULTS: From 1988 to 2001 124 diabetics received 140 vein bypass grafts for limb salvage, 95.7% already preoperatively with foot necrosis. Operative mortality rate was 1.4%, major morbidity rate was 9.3%, early graft failure rate 8.5% and early amputation rate was 3.8%. 2 year primary patency, primary assisted patency, secondary patency rates and limb salvage were 73.3%, 75.7%, 76.4% and 87.2%. 5 years results were 63.6%, 69.2%, 70.0% and 81.9% respectively. DISCUSSION: This series revealed exceptionally good results in patients with diabetes mellitus after short vein bypass grafting in concert with earlier studies since 1981. Compared to long femorodistal grafts there was no difference in longterm patency. Bypass grafting in diabetic foot syndrome is still regarded to have a poor prognosis. Just the contrary is the case. This study in concert with former studies revealed distal origin bypass grafting a durable and effective procedure to fight limb loss in diabetic foot syndrome. CONCLUSION: Distal origin vein bypass grafting is an excellent method just for patients with diabetes. Looking at limb salvage rates over 80 % in 5 years, this procedure should be offered more often suitable patients with diabetic foot syndrome.     

Are there angiographic predictors of success for vein bypass to the peroneal artery?

In order to evaluate the effect of angiographic run-off upon peroneal artery autogenous vein bypass patency and subsequent limb salvage, 53 autogenous vein peroneal artery bypasses performed for ischemic tissue loss were reviewed. All preoperative angiograms were evaluated according to three separate angiographic scoring systems that previously had been designed to quantify the severity of runoff resistance. None of the three scoring systems predicted either early bypass occlusion and/or major amputation. The cumulative 18-month primary patency and 24-month secondary patency rates were 71% and 90%, respectively. The 24-month limb salvage rate was 81%. Initial and intermediate-term salvage of limbs with ischemic tissue loss can be achieved by peroneal artery bypass. Angiographic scoring systems were poor predictors of bypass failure or major amputation.     

动脉自膨式支架置入治疗下肢缺血

目的探讨下肢各个部位动脉腔内自膨式支架置入治疗下肢缺血的疗效。方法对2002年1月-2006年3月支架治疗65例71条患肢的临床资料进行临床回顾性研究，其中52．3％（38／71）肢体为糖尿病下肢动脉硬化，47、7％（33／71）肢体为非糖尿病下肢动脉硬化。支架部位包括腹主动脉支架2例2条患肢2枚支架，腹主动脉及髂动脉闭塞行腹主动脉和单侧髂动脉支架置入1例3枚支架，髂动脉支架33例35条患肢38枚支架，髂动脉和股浅动脉同时支架置入6例6条息肢12枚支架，股浅动脉支架置入16例19条肢体23枚支架，股浅动脉和近端胭动脉病变同时支架置入5例6条患肢10枚支架，远端胭动脉支架2例2条患肢。结果65例随访2—50个月，平均16．1月，2例腹主动脉支架、1例腹主动脉与髂动脉支架同时置入全部通畅；髂动脉支架闭塞4例4条患肢，通畅率88．6％（31／35）；股浅动脉支架闭塞4例4条患肢，通畅率为78．9％（15／19）；股浅动脉与近端胭动脉支架闭塞1例，通畅率83．3％（5／6）；远端胭动脉支架2例全部闭塞；3例小腿动脉流出道主干动脉全部闭塞的支架术后平均5．6月仍然保持通畅。结论下肢动脉腔内支架置入可作为治疗主髂动脉病变的首选方法；对于股动脉和近段胭动脉病变也可根据情况适当选用，尤其是年老体弱，无法耐受动脉旁路移植手术的患者，也可以作为首选方法；对于膝下小动脉病变应慎重使用支架。     

Distal percutaneous transluminal angioplasty through infrainguinal bypass grafts.

AIM: to evaluate the results of transluminal angioplasty (PTA) performed through infrainguinal bypass grafts for stenotic or occlusive lesions at the distal anastomosis and/or in the runoff arteries. Design: retrospective clinical study. MATERIAL AND METHODS: forty-one patients underwent 57 procedures at the distal anastomosis (n=13), in the runoff arteries (n=32) or at both locations (n=12) at a median of 9.6 months (range, 2-76 months) after infrainguinal bypass grafting. Nineteen procedures were on the popliteal artery, the rest on the crural arteries. Eleven procedures related to occlusions less than 5 cm in length. RESULTS: technical success was achieved in 91%. Primary and primary assisted graft patency rates at 3 years were 32% and 53%, respectively. There were no significant differences in patency rates with regard to the graft material, the type of lesion, the level of PTA, the status of runoff and the use of thrombolysis before PTA. No patients underwent amputation as a direct consequence of failed PTA or graft occlusion. One patient underwent acute surgical intervention due to graft occlusion at the time of attempted PTA. CONCLUSION: the results of PTA at the distal anastomosis and/or in the runoff arteries in limbs with infrainguinal bypass seemed to be inferior to the results of surgical revisions reported in literature. However, as failed PTA did not jeopardise vein-patch angioplasty or jump grafting, it is a reasonable alternative to surgical intervention in selected cases.     

Surgery of popliteal artery aneurysms: a 12-year experience

BACKGROUND: Management of asymptomatic popliteal aneurysm is controversial, and the prognosis for acutely thrombosed aneurysm is notoriously poor. We evaluated the management and outcome for popliteal aneurysm. PATIENTS AND METHODS: A retrospective review of all patients with popliteal aneurysm between 1988 and 2000 was carried out. Fifty-two limbs were operated on in 41 patients. Data collected included findings at presentation, operative details, graft patency, limb salvage, complications, and 30-day mortality. RESULTS: Initial findings included acute ischemia (n = 14), no symptoms (n = 29), acute rupture (n = 2), chronic ischemia (n = 5), and symptoms of nerve or vein compressive (n = 2). All patients with symptomatic aneurysms and 22 patients with asymptomatic aneurysms (21 larger than 2 cm in diameter, 1 with thrombus at duplex ultrasound scanning) underwent surgery as first-line treatment. Of the 7 patients with asymptomatic aneurysm managed with surveillance with duplex ultrasound scanning, acute ischemia developed in three, 1 aneurysm ruptured, compressive symptoms developed in 1, and 2 remained asymptomatic but required surgery because of aneurysm enlargement (>2 cm). Of the 17 patients with acute ischemia, 13 had neurologic signs and underwent immediate thromboembolectomy (trifurcation alone in 8, ankle-level arteriotomy in 4) and bypass grafting (n = 12) or inlay grafting (n = 1), and the other 4 underwent intra-arterial thrombolysis initially. Of these 4 procedures, 2 were successful and had elective surgery; the other 2 required urgent surgery because of secondary distal embolism and failure of recanalization. Thirteen of the 17 grafts were to the crural vessels. Bypass grafting (medial approach) was used in 16 of the 17 patients with acute ischemia, all 5 patients with chronic ischemia, and the 8 patients with no symptoms. An inlay technique (posterior approach) was used in 16 patients with no symptoms, the 3 patients with symptoms of nerve or vein compression, and 1 patient with acute ischemia. The distal anastomoses were to the below-knee popliteal artery in 35 patients and the crural arteries in 15 patients, using autologous vein. Two of the patients with rupture underwent ligation alone, the other undergoing bypass grafting in addition. The overall 5-year primary patency rate was 69%, secondary patency rate was 87%, and limb salvage rate was 87%. Limb salvage was achieved in 14 of the 17 patients with acute ischemia. Patients with asymptomatic aneurysms had better secondary graft patency (100%) compared with symptomatic aneurysms (74%; P <.01). Acute ischemia, technique used, and crural artery grafts were not predictors of graft failure with either univariate or multivariate analysis. Symptomatic aneurysms were associated with more postoperative complications and greater 30-day mortality (4 of 28 vs 0 of 24). CONCLUSION: Thromboembolectomy followed by crural bypass grafting is an effective treatment for popliteal aneurysm with severe acute limb ischemia. Outcome is better with surgical management of asymptomatic popliteal aneurysm compared with symptomatic aneurysm.     

The distribution of atherosclerosis in the lower limbs.

Sixty-seven consecutive aortograms in non-diabetic patients were studied to establish the distribution of atherosclerosis in the arteries of 134 lower limbs. Prolonged filming and multiple exposures of the feet showed ankle vessels in 131 of the limbs (98%) and a pedal arch or collaterals in 126 (93%). In 51% of the limbs at least one of the calf arteries was occluded and only 24% had two patent arteries at ankle level. The pedal arch was complete in only 16%. The patency rate of the pedal arch was similar in all three symptom groups (p greater than 0.05). Two separate analyses were performed. The first was based on symptoms. Critical ischaemia was present in 18 limbs (13%), claudication in 69 limbs (52%) and 47 limbs were symptomless (35%). The second analysis was based on the sites of major occlusion. Occlusions were already present in 81% of the symptomless limbs, predominantly in the distal vessels. In limbs with claudication or critical ischaemia there were more occlusions above the knee (77 and 89%, respectively) than in limbs without symptoms (36%) (chi 2 = 27.60, p less than 0.001). Occlusion of the popliteal artery was significantly more frequent in the patients with symptoms of critical ischaemia (50%) than in either of the other two groups (chi 2 = 15.61, p less than 0.001). Atherosclerosis appears to develop in the small vessels of the calf and foot at an early stage. The extent of this involvement may influence the progression of symptoms and the outcome of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Urgent pedal bypass grafting for salvage of a critically ischaemic limb with a thrombosed popliteal aneurysm

The absence of infra-popliteal runoff in patients with acute limb-threatening ischaemia due to thrombosed popliteal aneurysm entails a high risk of amputation. If sufficient runoff cannot be restored by thrombolysis of crural arteries or by thrombectomy, the only chance to salvage the limb is pedal bypass grafting. The authors present a clinical case of acute lower limb ischaemia in a patient with popliteal aneurysm thrombosis and occlusion of the crural arteries treated successfully with urgent pedal bypass grafting with distal anastomosis to the dorsal pedal artery.     

Lower extremity revascularization with in situ saphenous vein for critical ischemia

Over a 3 1/2 year period, 55 limbs were revascularized with in situ saphenous vein bypass grafts in 49 patients. Ninety-five percent of grafts were constructed in patients with critical ischemia for limb salvage, and 5 percent were constructed for debilitating claudication. The proximal anastomosis was performed in the groin in all patients. The distal graft was taken to the popliteal artery in 45 percent and to a tibial or isolated popliteal segment in 55 percent, with 55 percent of the grafts having single-vessel runoff. The perioperative mortality rate was 7 percent. The primary immediate patency rate was 91 percent and the secondary immediate patency rate was 98 percent at 1 month. The cumulative patency rate at 42 months was 85.4 percent overall, 86.6 percent for the tibial grafts, and 84 percent for the popliteal grafts. The cumulative limb salvage rate was 100 percent for the popliteal grafts, 90 percent for the tibial grafts, and 94.5 percent overall. All of the patients were followed and 3 required secondary revision. In situ vein bypass is a technically demanding procedure that can be performed successfully in high-risk patients with limbs with minimal runoff and can yield very high long-term patency and limb salvage rates in a community hospital setting.     

A new method of angiographic runoff evaluation in femorodistal reconstructions. Significant correlation with early graft patency

In 62 patients undergoing femorodistal bypass surgery, the foot vessel runoff was analyzed with a new grading system based on intraoperative postreconstruction serial angiography. The patients were divided into two groups according to the level of the distal anastomosis (proximal or low). Good runoff was defined as integrity of the anterior and/or posterior foot arch in proximal femorodistal grafts and integrity of both arches in low bypasses. In the proximal group, runoff was classified as poor when the arches were deficient or occluded, and in the low group, when only one arch was intact. The patency rate after 6 months was 81% in the good runoff group, whereas all grafts in patients with poor runoff were occluded. The new method allowed better prediction of the early outcome than does the primary and secondary pedal arch integrity concept.     

Cryopreserved saphenous vein allografts for below-knee lower extremity revascularization.

OBJECTIVE: Cryopreserved saphenous vein allografts have been offered as an alternative conduit for bypass in ischemic limbs. The authors examined the efficacy of this conduit for arterial bypass to the distal popliteal and tibial arteries in patients in whom autogenous vein was not available. SUMMARY BACKGROUND DATA: Previous experience with arterial and venous allografts has been unsatisfactory because of aneurysmal degeneration and poor patency. Endothelial loss and host rejection have been suggested as mechanisms of graft failure. Cryopreservation by modern techniques with rate controlled freezing, dimethyl sulfoxide (DMSO), and other cryopreservants, has addressed these issues and rekindled interest in vein allografts. METHODS: Over a period of more than 5 years, 115 cryopreserved vein allografts were implanted in 87 limbs to the distal popliteal (14) or tibial (101) arteries. The indication for surgery was rest pain in 56 procedures (49%), gangrene in 36 (31%), claudication in 21 (18%), and replacement of aneurysmal allografts in 2. Follow-up was 1 to 61 months (mean 25 months). RESULTS: There was no significant difference in patency related to site of proximal or distal anastomosis, patency of runoff vessels, use of anticoagulation, age, sex, diabetes, hypertension, smoking, indication, source of graft, or use of multiple segments. Revision was required in six grafts for aneurysmal dilatation. Histologic examination of explanted sections of allografts showed no immune response, and immunosuppressive drugs were not used. CONCLUSIONS: Although limb salvage has been satisfactory, long-term patency rates for cryopreserved vein allografts are poor when compared with autogenous vein. The cost of cryopreserved allografts far exceeds that of prosthetic grafts, for which comparable and superior results have been reported. Use of cryopreserved vein allografts should be reserved for situations in which adequate lengths of autogenous vein do not exist and the risk of infection of prosthetic grafts is high.     

Lower Extremity Revascularization without Preoperative Contrast Arteriography: Experience with Duplex Ultrasound Arterial Mapping in 485 Cases

This study reviews our experience with duplex ultrasound arterial mapping (DUAM) for preoperative evaluation in 466 patients (262 men) who underwent 485 lower extremity revascularization procedures from January 1, 1998 to May 30, 2001. Preoperative imaging consisted of DUAM alone in 449 procedures and DUAM and contrast angiography (CA) in 36. An attempt to image from the distal aorta to the pedal arteries was made in all the patients. The selection of optimal inflow and outflow bypasses anastomotic sites was based on a schematic drawing following DUAM examination. Inflow disease was also assessed by intraoperative pressure gradient (IPG) between the distal anastomosis and radial arteries, and completion arteriography of the runoff vessels was obtained, which was correlated with the preoperative findings. Indications for surgery were severe claudication in 91 (19 %) limbs, tissue loss in 197 (40%), rest pain in 113 (23%), acute ischemia in 46 (10%), popliteal aneurysm in 18 (4%), superficial femoral artery aneurysm in 1, abdominal aortic aneurysm with claudication in 1, and failing graft in 18 (4%). Age ranged from 30 to 97 years (mean 72 ± 12 (SD) years) and risk factors such as diabetes, hypertension, use of tobacco, coronary artery disease, and end-stage renal disease were present in 45%, 45%, 44%, 44%, and 13% of the patients, respectively. One hundred twenty-one (25%) limbs had at least 1 previous ipsilateral revascularization. The mean DUAM time was 66 ± 20 (SD) min (30-150 min). Additional preoperative imaging was deemed necessary in 36 cases due to extensive ulcers, edema, severe arterial wall calcification, and very poor runoff. The distal anastomosis was to the popliteal artery in 173 cases and to the tibial and pedal arteries in 255. Inflow procedures to the femoral arteries, embolectomy, thrombectomy, balloon angioplasty, and patch angioplasty accounted for the remaining 57 cases. Overall, 6-, 12-, and -24- month secondary patency rates were 86%, 80%, and 66%, respectively. This early experience shows that high-quality arterial ultrasonography performed by a highly skilled vascular technologist may represent an alternative to conventional arteriography for patients in need of lower extremity revascularization. Because of limitations inherent to the technique and very poor runoff observed on ultrasonographic examination, additional preoperative imaging procedure's are needed for certain patients.