Autogenous arterial bypass grafts: durable patency and limb salvage in patients with inframalleolar occlusive disease and end-stage renal disease

OBJECTIVE: The purposes of this study were to determine whether autogenous arterial grafts to distal pedal arteries improve the patency of grafts and limb salvage in patients with end-stage renal disease and nonhealing ischemic wounds and to better define the indications for autogenous arterial grafts. DESIGN: A review of consecutive patients with end-stage renal disease undergoing autogenous arterial grafts from 1994 through 1999 was carried out. The setting was a university hospital. All 11 patients with end-stage renal disease and nonhealing, ischemic wounds (stage IV SVS-ISCVS classification) undergoing autogenous arterial grafting from 1994 to 1999 were evaluated. Noninvasive studies confirmed inadequate perfusion pressures in all patients. Pre-bypass arteriography identified no major arteries patent at the level of the malleolus, with reconstitution of only a distal or branch pedal or plantar vessel less than 1 mm in diameter. Five patients with patent tibial vessels to just above the ankle underwent bypass surgery with autogenous arterial grafts alone. Six patients also had proximal occlusive disease that required grafts longer than the autogenous arterial grafts; in each of these six patients, an autogenous vein graft proximal to the autogenous arterial graft was placed through use of a composite technique. Inflow was from the common femoral artery in one patient, the popliteal artery in five patients, and a tibial artery in five patients. Outflow was to the medial plantar artery in five patients, the distal dorsalis pedis artery in three patients, the lateral plantar artery in two patients, and the superficial arch in one patient. The conduit was the subscapular artery in four patients, the deep inferior epigastric artery in four patients, the superficial inferior epigastric artery in two patients, and the radial artery in one patient. The main outcome measures were assisted primary graft patency and functional limb salvage rate. RESULTS: Follow-up ranged from 6 to 63 months (mean, 20 months); graft patency was determined by means of duplex scanning. All 11 patients are alive, and nine grafts are patent, including three after revision for graft stenosis. Assisted primary patency was 82% at 3 years. All nine patients with patent grafts remained ambulatory and had healed wounds or limited forefoot amputations. CONCLUSION: Autogenous arterial grafts were effective in treating limb-threatening ischemia in patients with end-stage renal disease and inframalleolar arterial insufficiency. Graft patency and limb salvage rates were higher than those reported for autogenous vein graft in these patients. Autogenous arterial grafting may therefore prove to be an effective alternative to autogenous vein grafting in selected patients.     

56例腘动脉以下肢体动脉缺血的血管重建术分析

目的总结腘动脉水平动脉闭塞血运重建术治疗的临床疗效。方法对2001年7月至2005年8月56例累及腘动脉及腘动脉以下三分支病变重建肢体血运进行回顾性分析。根据病变阻塞平面不同,采用不同的血管架桥,对多平面、多节段动脉闭塞采用聚四氟乙烯人工血管和自体静脉桥复合序贯架桥血运重建。结果术后平均随访17个月,移植血管一期通畅率67．3％,二期通畅率78．8％。结论复合序贯搭桥术治疗累及股浅-腘动脉水平以下多节段（平面）动脉闭塞症是一种较实用的方法,可有效解决自体血管不足和单纯使用人工血管腘动脉以下血管重建通畅率差的问题。     

Long-term results with autogenous tissue repair of traumatic extremity vascular injuries.

With extensive vascular injuries in which a vascular conduit is required, there is controversy as to whether an autogenous or prosthetic graft is preferable. The authors reviewed their experience with 91 extremity arterial injuries in which autogenous tissue was used to repair vascular injuries of the extremities. Twenty-two patients also had concomitant repair of associated venous injuries with autogenous vein grafts. Ten patients required amputations, despite patent grafts in five patients, because of severe muscle necrosis. Two patients had thrombosis of their vein grafts develop in the early postoperative period but did not require amputation. The authors identified only one late vein graft failure in a patient in whom an infected pseudoaneurysm developed. Three patients with extensive soft tissue injuries had infection develop in vein grafts, with subsequent massive bleeding that ultimately required arterial ligation. Among the 22 patients with repair of their venous injuries, occlusion of popliteal vein repairs was documented in two patients and suspected in three others. The remainder of patients had satisfactory results. The excellent results obtained in the vast majority of the authors' patients with extremity vascular injuries reinforces their preference for using autogenous tissue whenever a vascular conduit is required. Exceptions include patients with extensive soft tissue loss precluding adequate graft coverage, the repair of large vessels, and life-threatening emergencies when there is insufficient time to harvest and prepare a vein.     

Reversed vein bypass to infrapopliteal arteries. Modern results are superior to or equivalent to in-situ bypass for patency and for vein utilization.

In recent years many reports have attributed improved patency and improved vein utilization with lower extremity arterial bypass to infrapopliteal arteries to the use of the in-situ vein graft technique (ISVB). This report describes 110 reversed vein bypasses (RVB) to infrapopliteal arteries performed from 1980-1986. Thirty-three per cent of these patients did not have an intact ipsilateral greater saphenous vein. One hundred per cent of patients had autogenous RVB performed using a variety of techniques, including vein splicing, use of arm veins, lesser saphenous veins, branch veins, and use of graft origins distal to the common femoral artery. The life table patency figures for these grafts are 90%, 85%, and 85% at 1 year, 3 years, and 5 years, respectively. The life table limb salvage at 5 years is 93%. These figures for patency, vein utilization, and limb salvage for modern RVB to infrapopliteal arteries are clearly equal to or superior to any reported figures for ISVB. Results for RVB are greatly improved when compared with historic controls, as are results for ISVB. There is no evidence to date demonstrating superiority of one technique versus another.     

The durability of endoscopic saphenous vein grafts: a 5-year observational study

BACKGROUND: Endoscopic saphenous vein harvest has been explored as a minimally invasive alternative to a long continuous leg incision for removal of the greater saphenous vein. The endoscopic technique uses limited incisions (2-4) with extended "skin bridges" and videoscopic equipment for the dissection and removal of the greater saphenous vein. This study was undertaken to evaluate the long-term durability of saphenous vein grafts harvested by an endoscopic technique and used for lower extremity arterial revascularization. METHODS: All patients who underwent endoscopic saphenous vein harvesting for lower extremity arterial bypass grafting were prospectively followed for graft patency and risk factors. Grafts were surveyed with serial duplex scans at 3- to 6-month intervals over this 5-year study. Life-table methods were used to assess graft survival. A computerized registry and medical records were reviewed to determine graft patency and patient survival. RESULTS: From September 1994 to August 2000, 164 lower extremity arterial saphenous vein grafts harvested by an endoscopic technique were used for lower extremity arterial bypass grafting in 150 patients. The patient population included 111 males (75%) and 112 smokers (75%), but also included a high-risk cohort of 65 diabetic patients (43%) and 15 patients undergoing dialysis/renal transplant (10%). Twenty-eight patients (19%) died within the study period. With life-table methods, 1-, 3-, and 5-year secondary patency rates were 85% (+/- 3.2%), 74% (+/- 5.7%), and 68% (+/- 11.6%). Of the 30 failed grafts, 7 (4%) failed in the first month related to inadequate runoff (4), cardiac instability (2), and an additional surgical procedure (1). Twenty-three grafts (14%) failed between 1 and 42 months. Twenty-two (16%) of these 134 patent grafts underwent a second procedure to maintain patency (13 as primary-assisted patency and 9 as secondary patency). CONCLUSIONS: Endoscopic saphenous vein harvest for lower extremity arterial reconstruction provides a satisfactory conduit for lower extremity bypass grafting. Although increased manipulation from this limited access technique may incite an injury response in the vein, these vein grafts can maintain an adequate patency for lower extremity bypass grafting.     

The lesser saphenous vein: autogenous tissue for lower extremity revascularization

From December 1980 to December 1985, 54 patients underwent 56 lower extremity arterial procedures with the use of lesser saphenous vein (LSV) as graft material. LSV was used in all cases because a satisfactory greater saphenous vein (GSV) was unavailable to accomplish the proposed revascularization. Indications for operation were rest pain, ulceration, and gangrene (74%), and 26% had claudication alone. Fifty of the 56 procedures were femorotibial and femoroperoneal bypasses. Three graft combinations were used: LSV alone (29), lesser saphenous vein and other autogenous vein composites (LSV/AUTO) (14), and lesser saphenous vein with synthetic composite grafts (LSV/SYN) (13). Graft patency rates were determined by life-table analysis. The 3-year patency rate for LSV was 60% and for LSV/AUTO was 38%. LSV/SYN graft composites had a graft patency rate at 18 months of 21%. These data suggest that the LSV may function as an autogenous venous graft for lower extremity revascularization when sufficient GSV is not available.     

Incidentally detected stenoses proximal to grafts originating below the common femoral artery: do they affect graft patency or warrant repair in asymptomatic patients?

OBJECTIVE: Stenoses in infrageniculate arteries proximal to a lower extremity vein graft may reduce flow velocity through the bypass graft and are thought to predispose to graft occlusion. Repair of these lesions has been recommended to preserve graft function. This study was undertaken to better define the natural history of grafts below inflow lesions and to evaluate the necessity of repair to preserve graft patency. METHODS: From 1994 through 1999, patients undergoing lower extremity vein grafts by a single surgeon at a university hospital and an affiliated teaching hospital were placed in a prospective protocol for proximal infrageniculate native artery and graft surveillance through use of duplex scanning. The records of those patients with grafts originating distal to the common femoral artery were evaluated; they form the basis for this report. Arteriograms were obtained before bypass grafting, and no patient had a stenosis greater than 50% diameter reduction proximal to the graft origin. Follow-up scans were obtained from the common femoral artery through the graft and outflow artery. The peak systolic velocity and velocity ratio in an infrageniculate native artery proximal to the graft origin were recorded, as were the location and the time interval since the bypass graft. Repair of these proximal lesions was not performed during the course of this study. Revision of the bypass graft or its anastomoses was undertaken according to preestablished duplex scan criteria. RESULTS: During this time, 288 autogenous infrainguinal bypass grafts were performed, of which 159 originated below the common femoral artery; of these, 74 were from the superficial femoral artery, 29 from the profunda femoris artery, 49 from the popliteal artery, and 7 from a tibial artery. The maximum peak systolic velocity proximal to the graft origin was more than 250 in 38 arteries (25%) and more than 300 in 26 arteries (16%). The velocity ratio was 3.0 or more in 32 arteries at the same location as the peak systolic velocity and 3.5 or more in 23 arteries (15%), confirming hemodynamically significant stenoses at these sites. The location of peak systolic velocity was the common femoral artery in 81 patients (51%), the superficial femoral artery in 50 (31%), the popliteal artery in 22 (14%), and a tibial artery in 6 (4%). Follow-up ranged from 8 to 60 months (mean, 35 months). During follow-up, 19 patients died, 18 with patent grafts. Overall, nine grafts occluded. One of the occluded grafts had a velocity ratio greater than 3.0; this may have contributed to graft thrombosis. The other occlusions resulted from an unrepaired graft lesion in 2 patients, graft infection in 2 patients, and graft ligation necessitated by below-knee amputation in 2 patients. No cause for the occlusion could be identified in two of the grafts (neither had evidence of proximal arterial stenosis). Assisted primary patency rates were 95% and 91% at 3 and 5 years, respectively. CONCLUSIONS: For grafts originating distal to the common femoral artery, stenoses proximal to the graft do not affect bypass graft patency and do not require repair to prevent graft occlusion. Surveillance of these lesions may therefore be unnecessary, inasmuch as the repair of proximal lesions should not be undertaken to preserve graft function.     

The early fate of venous repair after civilian vascular trauma. A clinical, hemodynamic, and venographic assessment.

Repair of major venous injuries of the extremities has been advocated to improve limb salvage rates and to prevent the early and late sequelae of venous interruption. The contribution of venous repair to the surgical outcome remains controversial, however, in part because the fate of venous reconstruction has previously not been well defined. The current study was done to determine the early patency rate of venous repair, to compare the accuracy of various methods used to assess venous patency, and to analyze the relationship between early venous patency and surgical outcome. During a recent 27-month period, 36 patients with major extremity venous injuries were treated by venous reconstruction; 34 patients (94%) had an associated major arterial injury that also required repair. Venous repair was performed in the upper extremity (22%) as well as the lower extremity (78%) using various reconstructive methods, including lateral repair (17%), end-to-end anastomosis (11%), autogenous vein patching (25%), interposition autogenous vein grafting (42%), and panelled autogenous vein grafting (6%). After operation, venous repair patency was evaluated by clinical examination, impedence plethysmography, and Doppler ultrasonography, and contrast venography. There were no perioperative deaths in these 36 patients. The limb salvage rate was 100% and all 34 major arterial repairs were patent at the time of hospital discharge. Venography performed on the seventh postoperative day demonstrated that 14 venous repairs had thrombosed (39%) and that 22 had remained patent (61%). Local venous repair had a significantly lower thrombosis rate (21%) than those requiring interposition vein grafting (59%) (p less than 0.03). Compared with venography, the clinical evaluation was 67% accurate in the assessment of venous repair patency, and the noninvasive examination was 53% accurate. In conclusion, a substantial percentage of venous repairs will thrombose in the postoperative period, especially if interposition vein grafting is used. However, in this series limb salvage was not adversely influenced by an unexpectedly high rate of venous repair thrombosis. In addition, clinical evaluation and noninvasive testing did not provide an accurate assessment of venous patency after venous repair.     

Bypass grafts to the ankle and foot

Two hundred forty-three bypasses to paramalleolar arteries were performed in 224 extremities of 208 patients since 1971; 166 were implanted in men (68%) and 77 in women (32%). The median age was 73 years. Gangrene (61%), nonhealing ulcer (15%), rest pain (22%), and trauma (2%) were the indications for bypass. Usual risk factors were noted: diabetes (65%), smoking (51%), heart disease (46%), and hypertension (45%). The extent of occlusive disease dictated three graft configurations: long grafts originating in arteries proximal to the adductor tendon (n = 111), short grafts originating at or below the popliteal artery (n = 88), and jump grafts originating near the distal end of a previous femorodistal bypass (n = 44). The association between diabetes (incidence 80%) and gangrene (75%) in patients with short grafts was statistically significant (p less than 0.01). The 2-year secondary patency rate of long in situ grafts was 92% compared with 72% for other autogenous vein long grafts. The limb salvage rate for all autogenous vein long grafts was 90% at 3 years. The secondary patency rate at 3 years for short grafts was 81% and the limb salvage rate was 80%. There were four amputations with patent grafts. Primary and secondary patency rates of jump grafts were similar (53%), whereas the limb salvage rate was 89% at 2 years. Patency and limb salvage rates of rarely employed nonautogenous conduits were less than 35% at 1 year (long grafts). Bypass grafts to the ankle and foot are effective and durable and should be performed with autogenous vein.     

Cryopreserved saphenous vein allogenic homografts: an alternative conduit in lower extremity arterial reconstruction in infected fields.

Autologous saphenous veins are considered the best arterial substitute for lower extremity revascularization in infected fields. The search continues for a vascular conduit in instances when an autologous biologic grafting is not feasible. Herein we report our experience with eight patients in whom cryopreserved saphenous vein allogenic homografts were used in 10 lower extremity arterial reconstructions for limb salvage with coexisting infection. Six patients with eight prosthetic grafts including four femoropopliteal, two femorotibial, a femorofemoral, and a femoroperoneal graft required complete or partial graft excision as a result of overt infection. The two remaining patients included one with an infected femoral pseudoaneurysm and another with extensive chemical burns. All cryopreserved saphenous vein allogenic homografts were of identical match to the ABO/Rh blood groupings of the recipient patients. No immunosuppressive drugs were administered after operation. Mean follow-up was 9.5 months (range, 6.0 to 14.0 months). One patient died 5 weeks after operation with a patent graft. Two grafts occluded during follow-up; in one graft, patency was restored with thrombectomy alone. The remaining seven arterial reconstructions continue to be patent with no evidence of aneurysmal dilation with complete eradication of the primary infection. These preliminary findings suggest that cryopreserved saphenous vein allogenic homografts can serve as interim conduits for lower extremity arterial reconstruction to preserve limb viability when autogenous conduits are unsatisfactory or unavailable. Further definitive reconstruction may thereafter be necessary once sepsis is eradicated and sufficient wound healing is achieved.     

Management and short-term patency of lower extremity venous injuries with various repairs

BACKGROUND: Although several methods of repair of extremity venous injuries have been shown to be efficacious, patency rates have varied significantly from center to center. METHODS: A retrospective review was made of treatment outcomes of adult and pediatric patients with major venous injuries of the lower extremity. RESULTS: From 1997 to 2002, 82 patients sustained 86 major lower extremity venous injuries. Venous injuries were treated with primary repair in 27, complex repair in 37 (autogenous vein, 10, and ringed polytetrafluoroethylene [PTFE], 27) and ligation in 20. Prior to repair, temporary intraluminal venous shunts were used in 18 patients. Follow-up duplex imaging or venography or both were performed on 42 extremities at a mean of 10.9 +/- 7.1 days after repair with an overall patency rate of 73.8% (primary repair 76.5%; autogenous vein graft 66.7%; and PTFE 73.7%). CONCLUSIONS: Overall early patency rate of venous repairs performed by an experienced trauma team is similar irrespective of the type of repair. The use of temporary intraluminal shunts is acceptable in selected circumstances, while ringed PTFE grafts are reasonable alternatives when the contralateral saphenous vein is too small.     

Short-term and midterm results of an all-autogenous tissue policy for infrainguinal reconstruction

Saphenous vein is the optimal conduit for infrainguinal vascular reconstruction. In instances in which this vein is unavailable or of "poor quality," reliance has been placed on a variety of prosthetic materials for bypass grafting. However, long-term patency with these prosthetic grafts has been disappointing. In January 1985 we instituted a policy of using exclusively autogenous tissue for infrainguinal arterial reconstruction. During the ensuing 3-year period, 203 patients underwent 266 arterial operations below the inguinal ligament, with a prosthetic graft used in only 11 instances (4%). No patient was denied surgery for limb salvage because of a lack of available autogenous vein. Thirty-three percent of procedures were performed for failure of prior revascularization and 73% for limb salvage. The 3-year cumulative primary patency rate for all autogenous procedures was 72%. Procedures were divided into those that used greater saphenous vein (patency 77%) vs autogenous alternatives such as bypass with arm vein or lesser saphenous vein, vein patch angioplasty, and endarterectomy (patency 64%). The operative mortality rate was 1.4% and the 3-year limb salvage rate was 89%. Autogenous infrainguinal reconstruction can be performed in almost every instance with acceptable results, suggesting that the need for prosthetic bypass grafts in the lower extremity is less than has been previously reported.     

Autogenous Profundaplasty: The Key to Long-term Patency in Secondary Repair of Aortofemoral Graft Occlusion

The records of 281 patients undergoing aortic grafting to 522 femoral arteries over a period of 18 years were reviewed. Fifty-four patients suffering graft limb occlusion to 71 femoral arteries requiring subsequent secondary repair were identified for detailed analysis. Occlusive disease of the profunda femoris artery was identified as the primary cause of thrombosis. Repair consisted of profunda femoris angioplasty, and transfemoral retrograde graft thrombectomy was possible in all but three instances which were managed by cross-over femoral-femoral bypass. In no instance was laparotomy and abdominal graft replacement necessary. The 30 day operative survival and graft patency were 100%. Analysis of factors that have influenced late graft patency demonstrated that the key factors were the method of profundaplasty and the association of diabetes mellitus. When autogenous profundaplasty (on-lay arterial patches, saphenous vein, or limited endarterectomy) was employed, the overall patency combining diabetics and non-diabetics was two and one-half times greater than when profundaplasty was performed with an on-lay Dacron((R)) patch. If diabetics were separated from nondiabetics in the autogenous angioplasty group, the 36 month patency for non-diabetics was 85%, and 0% for diabetics. We conclude that autogenous profundaplasty provides considerable advantage from the standpoint of long-term patency and that the diabetic patients are relatively poor candidates for secondary arterial repair of an occluded aortofemoral bypass graft.     

Results of venous interposition grafts in arterial injuries

Controversy continues regarding the use of PTFE versus autogenous vein grafts in the repair of arterial injuries. This study was designed to evaluate the results of a large series of autogenous interposition vein grafts used for arterial trauma. The charts of 191 patients with 192 arterial injuries repaired with an autogenous vein graft were reviewed. Specific areas of interest included graft-related complications such as thrombosis, infection, rupture, incidence of amputation, and mortality. Seventy-six per cent of the injuries were due to penetrating trauma. Forty-five per cent involved the upper and 51% the lower extremity. Shock (B. P. less than 80) occurred in one third of the patients. There were 23 (12%) graft-related complications. Sixteen (8.3%) of the grafts thrombosed. Three of these patients required an amputation and one a nephrectomy. Seven grafts (3.6%) became infected; all seven eventually ruptured. Five of these patients required an amputation. Eighteen patients (9.4%) required amputation; however, only eight (4.2%) of these cases were graft related. One patient died from non-graft-related multiple organ failure, establishing a mortality rate of 0.5%. Based on the data reported in this series, it is concluded that autogenous grafts continue to provide a safe, readily accessible, and effective means by which selected arterial injuries can be repaired.     

Autogenous composite vein bypass graft for infrainguinal arterial reconstruction

PURPOSE: Lower extremity arterial reconstruction in the absence of adequate greater saphenous vein remains a challenging problem in contemporary vascular practice. The purpose of this review is to evaluate the long-term results of autogenous composite vein grafts used for infrainguinal arterial bypass grafting. METHODS: We retrospectively evaluated a prospective vascular registry and reviewed inpatient and office records. RESULTS: From June 1983 to September 1999, 165 autogenous composite vein infrainguinal bypass grafts were performed in 154 patients (87 men, 67 women; mean age, 69 years). The mean follow-up was 25 months (range, 3-147). Patients had the usual risk factors, including a 30% incidence of prior coronary bypass grafting. Forty-eight percent of bypass grafts were performed after failed previous reconstructions, and 90% were performed for limb salvage. The conduits were comprised of 2 segments (75%), 3 segments (23%), and 4 segments (2%). The distal anastomosis was at the popliteal level in 17% and the tibial/pedal level in 83%. The 30-day operative mortality rate was 1.8%. Perioperative graft failure (< 30 days) occurred in 18 bypass grafts (11%), resulting in early amputation (< 30 days) in 1.2%. The overall 5-year cumulative patency rates were 44% +/- 5% for primary patency, 63% +/- 5% for primary-assisted patency (PAP), and 65% +/- 5% for secondary patency (SP). A high revision rate for stenosis or thrombosis was required during follow-up to maintain patency of the grafts (27%). Limb salvage was 81% +/- 5% at 5 years. Primary reconstructions with composite vein fared significantly better than secondary reconstructions (SP 76% vs 54% at 5 years, P <.01). Arm vein composites showed superior patency compared with greater saphenous vein composites (SP 79% vs 61% at 5 years, P <.05). CONCLUSIONS: Infrainguinal reconstruction with autogenous composite vein results in durable graft patency and limb salvage rates in patients with few alternatives for revascularization. Intensive graft surveillance with aggressive graft revision is necessary to achieve these results.     

Anterior Chest Wall Arteriovenous Grafts: An Underutilized Form of Hemodialysis Access

Vascular access dysfunction is a major cause of morbidity in hemodialysis (HD) patients and the maintenance of a functional vascular access is an ongoing challenge. An upper extremity autogenous arteriovenous fistula (AVF) that preferentially involves the cephalic vein is the access of choice for hemodialysis patients, followed by autogenous AVF utilizing the basilic vein and the use of prosthetic arteriovenous grafts (AVG). Unfortunately, upper extremity options for vascular access rapidly become exhausted in a sub‐group of patients and use of alternative sites for access becomes necessary. An anterior chest wall graft, in which the axillary artery is anastomosed to either the ipsilateral or contralateral axillary veins, is a reasonable option in patients who have exhausted their upper extremity as vascular access sites, but still have patent central veins. Major indications include patients predisposed to steal syndrome as well as those with stenotic outflow veins necessitating over the shoulder extension of a brachio‐axillary graft. Recent data suggest that primary and secondary patency rates in anterior chest wall grafts are equivalent to upper extremity AVGs, making them a reasonable alternative vascular access option. This review will discuss the anatomical variations, percutaneous interventions, patency and longevity of anterior chest wall AV grafts.     

Early and 1 year angiographic evaluation of graft patency in off-pump coronary bypass surgery via sternotomy

The goal of this study was to evaluate the early and 1 year postoperative angiographic results in patients who underwent coronary revascularisation for multivessel disease on beating heart via sternotomy. One hundred eleven consecutive patients receiving 272 grafts, operated by the same surgeon were studied (2.5 grafts/patient). The quality of the graft and the anastomoses was systematically evaluated by coronary angiography between 1 and 15 days after surgery. Eighty-seven patients (209 grafts) of the initial cohort (78.3%) were repeatedly controlled by angiography between 5 and 24 months. Angiographic findings were studied and classified according to Fitzgibbon classification. Overall early graft patency was 96.4%. Arterial graft patency was 96.4% and vein graft patency was 96.3% (P=1). Of the grafts (88.7%) were Grade A, 21 grafts (7.7%) Grade B and 10 grafts (3.6%) were occluded (Grade O). The second angiographic control revealed a patency rate of 94.8%, arterial graft patency was 95.4% and vein graft patency was 93.8% (P=0.9): 91.5% of patent grafts were graded (A), 3.3% graded (B) and 5.2% graded (O). A comparison between early and late angiograms revealed: two-stenosis de novo, three-occlusion de novo and decrease or disappearance of the stenosis in 13/21 graft, 11 arterial and two vein grafts (61.9%). In this study, the early and 1 year postoperative patency rate seems to be equivalent to coronary bypass with pump, however, a randomised study is needed to compare both approaches. Most of the stenosis detected at the early coronary angiography could decrease or disappear, especially in arterial grafts.     

Below-knee bypass for limb salvage. Comparison of autogenous saphenous vein, polytetrafluoroethylene, and composite dacron-autogenous vein grafts

Autogenous saphenous vein was used preferentially for 92 below-knee bypass procedures (44 femoral-distal popliteal and 48 femoral-distal tibial or peroneal) performed for limb salvage in 87 adult male patients during a 30-month period of study. When a saphenous vein was unavailable or of unsuitable length or diameter, we randomly used expanded polytetrafluoroethylene (PTFE) and composite Dacron-autogenous vein (DV) grafts. With good run-off, all grafts have remained patent. However, with poor run-off, cumulative patency by the life table method decreased to 54% for autogenous saphenous vein and 45% for PTFE, which was not significantly different. All composite DV grafts used with poor run-off became occluded within the first ten months of the study. We continue to recommend use of autogenous saphenous vein for revascularization of the ischemic lower extremity. When a suitable saphenous vein is unavailable, PTFE is a satisfactory alternative graft that is superior to composite DV grafts.     

Effect of thromboxane synthetase inhibition on canine autogenous vein grafts

This study examined the effect of an orally active thromboxane (TXA2) synthetase inhibitor (TSI) on the patency, TXA2 production, and platelet accumulation of reversed autogenous vein grafts. Ten dogs received TSI (U-63557A) 10 mg/kg po q8 hr for 6 weeks, beginning 24 hr prior to surgery, while 15 control dogs were untreated. One jugular vein was harvested and stored in 37 degrees C saline for 1 hr to induce mild endothelial injury (stored). Normal and stored jugular vein grafts (8 cm) were then implanted in opposite femoral arteries while 3-cm segments of the same veins were implanted in the carotid arteries. Femoral graft flow was restricted with a 5 Fr distal arterial stenosis and patency determined by arteriography at 1, 2, 4, and 6 weeks. Vein graft endothelial surface TXB2 production was measured by RIA at graft implantation and in carotid grafts harvested at 1 week. 111In-labeled platelets were given iv 24 hr prior to carotid graft harvest to determine graft-platelet deposition. TSI treatment improved early (1 week) femoral vein graft patency from 63 to 89% (P less than 0.05), a trend that persisted for 6 weeks. Warm saline storage reduced 1-week graft patency from 83 to 63% (P less than 0.05), a difference that decreased with time. TSI treatment resulted in a marked decrease in TXB2 production, but was not associated with decreased 111In-labeled platelet deposition in carotid vein grafts. Warm saline storage increased graft-platelet deposition which was predominant at the arterial anastomoses. TSI treatment may improve early vein graft patency during the transient period of endothelial injury.     

Preserved arterial grafts in microvascular surgery

The patency rates of arterial grafts preserved by immersion in 70% alcohol and arterial grafts preserved by ficin digestion and dialdehyde tanning were compared with the patency rate of fresh autogenous vein grafts in 5-mm defects in the femoral arteries of 50 rats. The overall patency rate for the fresh vein grafts was 90%. The patency rate at 2 weeks for the alcohol preserved arterial grafts was 40%; the patency rate for the dialdehydetanned arterial grafts at 2 weeks was 30%. The difference between the rates for the fresh vein grafts and the alcohol-preserved and dialdehyde-tanned grafts was statistically significant (P < 0.01 and P < 0.001, respectively). At 2 months there was no statistically significant difference in the rates between the autogenous vein grafts and the preserved arterial grafts, probably because of recanalization of grafts that had occluded primarily. From the data, it is concluded that fresh autogenous vein grafts are still superior to preserved arterial grafts in microvascular surgery.