Autogenous Vein Bypass Grafts Research Articles

Heterogeneous and dynamic lumen remodeling of the entire infrainguinal vein bypass grafts in patients

ObjectiveTo examine the regional variation and temporal change in lumen size along the entire autogenous vein bypass graft used for treating arterial occlusive disease in lower extremity and to explore the factors associated with graft expansive or constrictive remodeling. MethodsPatients were prospectively scanned using contrast-enhanced computed tomography at 1 week and 1, 6, and 12 months postoperatively to obtain lumen cross-sectional areas at 1-mm intervals along the entire grafts. Graft lumen remodeling characteristics and the associated demographic and clinical factors were examined. ResultsFifty-six patients with at least two consecutive computed tomography scans were analyzed. Patients with a composite or longer graft, or with diabetes, had a larger lumen cross-sectional area variation along the graft. The mean lumen cross-sectional areas of all the grafts demonstrated no significant changes through 12 months. However, individually, graft remodeling was time dependent and there was a more dramatic change in lumen cross-sectional area within the first postoperative month. At 12 months, a near equal distribution between expansive and constrictive grafts existed. A negative relation between the initial lumen diameters and the subsequent lumen diameter changes was observed. Eleven grafts failed within 12 months; failed and patent grafts had similar mean lumen cross-sectional areas at all four time points, but failed grafts had a larger maximal local cross-sectional area reduction from 1 week to 1 month (58.0 ± 6.7% vs 38.1 ± 3.1%, mean ± standard error of the mean, failed vs patent, P = .004). Black patients had a smaller mean lumen cross-sectional area than white patients at all four time points and also had a higher early percent mean area reduction (−20.5 ± 6.3% vs −1.0 ± 3.7%, black vs white, P = .018). Cilostazol use was associated with early expansive graft remodeling. ConclusionsVein grafts remodel heterogeneously and dynamically. Remodeling is associated with initial graft lumen size, race, and cilostazol use. It is found that remodeling that produces some critical minimum area or maximal percent reduction during the first postoperative month may predispose to vein graft failure. These findings offer insight into further investigation to examine the underlying mechanisms and opportunities to improve graft remodeling and durability.

Surgical treatment for chronic lower limb ischemia: A report of 60 cases

Objective To explore the clinical characteristics and treatment strategy of chronic lower limb arterial ischemic. Methods The clinical data of 60 patients with chronic lower limb arterial ischemic-treated from January 2017 to May 2017 were analyzed retrospectively (63 affected limbs). According to the patient's physical condition, clinical symptoms and pathological features, individualized surgical treatment was selected, including autogenous great saphenous vein or artificial blood vessel bypass grafting, artery intima stripped, balloon dilatation, stenting, intracavity volume reduction, or hybrid procedures. The ankle brachial index of preoperative and postoperative 3 months was monitored, and patients were classified according to the Rutherford classification standard. Results Sixty cases were underwent surgery treatment, three patients were treated with bilateral lower limbs in the same period, successfully 58 cases and success rate reached 96.67%. One case was subjected to amputation, and 1 case died (cardiovascular disease). Postoperative 3 month follow-up, the Rutherford grading of 59 affected limbs was improved markedly, average ankle brachial index of postoperative was higher than preoperative (P<0.05). Six cases of patients with ulcer were cured, the ulcer surface of 2 cases were significantly narrowed. Conclusions The incidence of chronic lower limb arterial ischemic is increasing year by year, the treatment ideas are constantly updated. It is safe and effective to select individualized treatment according to the patients' physical condition, clinical symptoms and pathological feature. However it still needs to enlarge the sample and extend the time of follow-up to verify this point. Key words: Ischemia/SU; Lower extremity/PA

Invited commentary

Autogenous vein bypass grafting remains an important therapeutic option for patients with peripheral vascular disease. These vein grafts are durable; however, the development of de novo stenosis within the graft occurs in 30% to 50% of patients within the first several years. Despite multiple therapeutic interventions and vein graft manipulations, the incidence of vein graft disease has not changed over the last 30 years. Basic research has focused on endothelial cells, smooth muscle cells, and extracellular matrix as the responsible culprits for the intimal hyperplastic lesion. However, studies have now shown that the adventitial layer may have a more dynamic role in the intimal hyperplastic lesion. Furthermore, recent studies have demonstrated the potential role of genetic variability in the p27 Kip1 gene as a determinant of clinical outcomes in patients with cardiovascular disease and after clinical interventions. The authors present a provocative in vitro study of human venous adventitial and smooth muscle cells that shows that the p27 single nucleotide polymorphism (p27 KIP1-838C>A) is functional and that the levels of p27 messenger RNA and protein were higher in the cells with the AA genotype compared with the CC genotype. Knockdown of p27 increases growth of both cell types with the AA genotype but not those with the CC genotype. What, however, is groundbreaking in their study is the differential effect of the p27 single nucleotide polymorphism on adventitial cell growth. They noted that adventitial cells of the AA genotype grew significantly more slowly than those with the CC genotype. In this study, only the adventitial cells, and not the smooth muscle cells, are responsible to the inhibitory effects of the protective AA genotype in cell growth. The adventitial layer has been noted to have vascular fibroblasts, perivascular adipocytes, and progenitor cells, which have been shown to affect vascular smooth muscle cell phenotype and growth. How these components interact to achieve the complex intimal hyperplastic lesion is still not known. However, using mouse model technology and lineage tracing technology to discover the cells or cells that are really responsible for the intimal hyperplastic lesion and, therefore, more precisely targeting treatment, could one day allow for the treatment of this disease that has been plaguing long-term vascular surgical outcomes for the last 40 years. The opinions or views expressed in this commentary are those of the authors and do not necessarily reflect the opinions or recommendations of the Journal of Vascular Surgery or the Society for Vascular Surgery. A single nucleotide polymorphism of cyclin-dependent kinase inhibitor 1B (p27Kip1) associated with human vein graft failure affects growth of human venous adventitial cells but not smooth muscle cellsJournal of Vascular SurgeryVol. 67Issue 1PreviewCyclin-dependent kinase inhibitor 1B (p27Kip1) is a cell-cycle inhibitor whose -838C>A single nucleotide polymorphism (rs36228499; hereafter called p27 SNP) has been associated with the clinical failure of peripheral vein grafts, but the functional effects of this SNP have not been demonstrated. Full-Text PDF Open Archive

Simulation of Anastomosis in Coronary Artery Bypass Surgery.

Developing cardiac surgical skills and experience takes years of practice. Cardiac trainees need to develop technical proficiency in order to enhance quality of care and patient safety. Simulation-based models are common resources for teaching procedural skills in both undergraduate and postgraduate medical education. Suitable and accessible educational platforms can play a progressively important role in the training process for young surgeons in the area of cardiac surgery. Coronary artery bypass graft (CABG) surgery consists of a wide range of pathologic anatomies and surgical techniques. In this paper we introduce a novel, synthetic, biomimetic platform that allows for the realistic practice of the CABG surgery. The prototype uses a polyvinyl alcohol hydrogel which has been designed to mimic the geometric properties of vasculature. The proposed models look and feel like human tissue and possess somewhat consistent mechanical properties. In this study, we apply the platform to simulate a case of autogenous saphenous vein bypass grafting of a patient. An autogenous saphenous vein graft is placed from the aorta to the left anterior descending coronary artery. The standard procedures of the coronary artery bypass surgery were successfully simulated. Using the proposed technology, other complicated surgeries such as end to end, side to end, and sequential anastomoses can be simulated such that these models lend themselves very well to various types of anastomoses.

The correlation between computed tomography and duplex evaluation of autogenous vein bypass grafts and their relationship to failure

Duplex ultrasound (DUS) imaging for vein bypass graft (VBG) surveillance is confounded by technical and physiologic factors that reduce the sensitivity for detecting impending graft failure. In contrast, three-dimensional computed tomography angiography (CTA) offers high-fidelity anatomic characterization of VBGs, but its utility in detecting at risk grafts is unknown. The current study analyzed the correlation between DUS and CTA for detection of vein graft stenosis and evaluated the relationship of the observed abnormalities to VBG failure. Consecutive lower extremity VBG patients underwent surveillance with concurrent DUS imaging and CTA at 1 week and at 1, 6, and 12 months postoperatively. A standardized algorithm was used for CT reconstruction and extraction of the lumen geometries at 1-mm intervals. At each interval, CT-derived cross-sectional areas were coregistered and correlated to DUS peak systolic velocities (PSVs) within six predesignated anatomic zones and then analyzed for outcome association. Vein graft failure was defined as pathologic change within a given anatomic zone resulting in thrombosis, amputation, or reintervention within the 6-month period after the observed time point. The study recruited 54 patients, and 10 (18%) experienced failure ≤18 months of implantation. The expected inverse relationship between cross-sectional area and PSV was only weakly correlated (Spearman rank coefficient = -0.19). Moderate elevations in the PSV ratio (PSVr; 2-3.5) were frequently transient, with 14 of 18 grafts (78%) demonstrating ratio reduction on subsequent imaging. A PSVr ≥3.5 was associated with a 67% failure rate. CT stenosis <50% was highly correlated with success (0 failures); however, high-grade (>80%) CT stenosis was more likely to succeed than to fail (25%). Significant discordance between CT and DUS was found in 18 patients. Although 14 of these patients had CT stenosis >70% with a PSVr <3.5, subsequent failure occurred in only two. Conversely, graft failure occurred in three of four patients with CT stenosis <70% but PSVr >3.5. Focused analysis of these patients using computational fluid dynamic modeling demonstrated that vein side branches, local tortuosity, regional diameter variations, and venovenostomies were the drivers of these discrepancies. This analysis demonstrated that a PSVr ≥3.5 is strongly correlated with VBG failure, whereas the natural history of moderately elevated PSVr (2-3.5) is largely clinically benign. Although minimum stenosis on the CT scan was highly predictive of success, high-grade CT stenosis was infrequently associated with failure. The interaction of anatomic features with the local flow dynamics was identified as the primary confounder for a direct correlation between CT and DUS imaging.

Hemodynamic conditions in a failing peripheral artery bypass graft

The mechanisms of restenosis in autogenous vein bypass grafts placed for peripheral artery disease are not completely understood. We investigated the role of hemodynamic stress in a case study of a revised bypass graft that failed due to restenosis. The morphology of the lumen was reconstructed from a custom three-dimensional ultrasound system. Scans were taken at 1, 6, and 16 months after a patch angioplasty procedure. Computational hemodynamic simulations of the patient-specific model provided the blood flow features and the hemodynamic stresses on the vessel wall at the three times studied. The vessel was initially free of any detectable lesions, but a 60% diameter-reducing stenosis developed during the 16-month study interval. As determined from the simulations, chaotic and recirculating flow occurred downstream of the stenosis due to the sudden widening of the lumen at the patch location. Curvature and a sudden increase in the lumen cross-sectional area induced these flow features that are hypothesized to be conducive to intimal hyperplasia. Favorable agreement was found between simulation results and in vivo Doppler ultrasound velocity measurements. Transitional and chaotic flow occurs at the site of the revision, inducing a complex pattern of wall shear as computed with the hemodynamic simulations. This supports the hypothesis that the hemodynamic stresses in the revised segment, produced by the coupling of vessel geometry and chaotic flow, led to the intimal hyperplasia and restenosis of the graft.

Challenges of Distal Bypass Surgery in Patients with Diabetes

Surgical revascularization of the lower extremity using bypass grafts to distal target arteries is an established, effective therapy for advanced ischemia. Recent multicenter data confirm the primacy of autogenous vein bypass grafting, yet there remains significant heterogeneity in the utilization, techniques, and outcomes associated with these procedures in current practice. Experienced clinical judgment, creativity, technical precision, and fastidious postoperative care are required to optimize long-term results. The diabetic patient with a critically ischemic limb offers some specific challenges; however, numerous studies demonstrate that the outcomes of vein bypass surgery in this population are excellent and define the standard of care. Technical factors, such as conduit and inflow/outflow artery selection, play a dominant role in determining clinical success. An adequate-caliber, good-quality great saphenous vein is the optimal graft for distal bypass in the leg. Alternative veins perform acceptably in the absence of the great saphenous vein, whereas prosthetic and other nonautogenous conduits have markedly inferior outcomes. Graft configuration (reversed, nonreversed, or in situ) seems to have little effect on outcome. Shorter grafts have improved patency. Inflow can be improved by surgical or endovascular means if necessary, and distal-origin grafts (eg, those arising from the superficial femoral or popliteal arteries) can perform as well as those originating from the common femoral artery. The selected outflow vessel should supply unimpeded runoff to the foot, conserve conduit length, and allow for adequate soft-tissue coverage of the graft and simplified surgical exposure. This review summarizes the available data linking patient selection and technical factors to outcomes and highlights the importance of surgical judgment and operative planning in the current practice of infrainguinal bypass surgery.

Challenges of distal bypass surgery in patients with diabetes: Patient selection, techniques, and outcomes

Surgical revascularization of the lower extremity using bypass grafts to distal target arteries is an established, effective therapy for advanced ischemia. Recent multicenter data confirm the primacy of autogenous vein bypass grafting, yet there remains significant heterogeneity in the utilization, techniques, and outcomes associated with these procedures in current practice. Experienced clinical judgment, creativity, technical precision, and fastidious postoperative care are required to optimize long-term results. The patient with diabetes and a critically ischemic limb offers some specific challenges; however, numerous studies demonstrate that the outcomes of vein bypass surgery in this population are excellent and define the standard of care. Technical factors, such as conduit, and inflow/outflow artery selection play a dominant role in determining clinical success. An adequate caliber, good quality great saphenous vein (GSV) is the optimal graft for distal bypass in the leg. Alternative veins perform acceptably in the absence of GSV, whereas prosthetic and other non-autogenous conduits have markedly inferior outcomes. Graft configuration (reversed, non-reversed, or in situ) seems to have little influence on outcome. Shorter grafts have improved patency. Inflow can be improved by surgical or endovascular means if necessary, and distal-origin grafts (eg, those arising from the superficial femoral or popliteal arteries) can perform as well as those originating from the common femoral artery. The selected outflow vessel should supply unimpeded runoff to the foot, conserve conduit length, allow for adequate soft tissue coverage of the graft, and simplified surgical exposure. This review summarizes the available data linking patient selection and technical factors to outcomes, and highlights the importance of surgical judgment and operative planning in the current practice of infrainguinal bypass surgery.

Repair of ventricle free wall rupture after acute myocardial infarction: a case report

IntroductionAcute myocardial infarction (AMI) may culminate in sudden death by ventricular fibrillation, cardiogenic shock, and cardiac rupture. We present a case of postinfarction rupture treated by direct closure and coronary artery bypass grafting after thrombolytic therapy.Case reportA 67-year-old woman with cardiac risk factors of hypertension, diabetes mellitus, and being post-menopausal was admitted complaining of chest pain and sweating. Thrombolytic therapy with streptokinase was started due to acute myocardial infarction. But, reperfusion criteria were not achieved. Echocardiography revealed a moderate pericardial effusion with mild right chamber collapse and pericardial thrombus. Cardiac catheterization revealed totally occluded left anterior descending (LAD) and circumflex coronary arteries. She was taken to the operating-room immediately. The pericardium was opened and a large amount of blood with thrombus was removed. Her hemodynamic indices improved immediately. There was active bleeding from multiple sites with a 4 mm rupture. Cardiopulmonary bypass was established. Direct closure of rupture was carried out. Reversed autogenous saphenous vein bypass grafts were placed to the LAD and second obtuse margin coronary arteries. Postoperative recovery was uneventful and she was discharged from hospital in good condition. She remained asymptomatic during first year following the surgery.ConclusionThis case demonstrates that left ventricular free wall rupture is not always fatal and that early diagnosis and emergency surgical therapy may be successful. The combination of surgical repair with revascularization should be considered, because 80% of patients who experience LVFWR have multivessel coronary artery disease.

Autogenous Vein Bypass Grafting for Arteriosclerosis Obliterans: A Comparison between the Recent and Previous Decades

Autogenous Vein Bypass Grafting for Arteriosclerosis Obliterans: A Comparison between the Recent and Previous Decades

Long term results of autogenous vein bypass grafts in femoropopliteal arterial occlusion.

The results of 329 consecutive autogenous vein grafts carried out between January 1962 and June 1973 have been reviewed. The 5- and 10-year mortality rates were 14.6 per cent and 18.7 per cent respectively. The corresponding patency rates were 70 per cent at 5 years and 34 per cent at 10 years, the lowest patency (27.8 per cent) occurring in below-knee anastomoses with grafts of 5 mm or less in diameter. As other have noted, the state of the popliteal--tibial run-off vessels had a considerable influence on long term patency rates. In severely ischaemic limbs, the limb salvage rate following this operation was 77 per cent. An analysis of symptoms, associated disease and complications is presented and discussed. No valid conclusions could be made regarding the effect of lumbar sympathectomy and postoperative anticoagulants on long term patency. This review has confirmed the findings of earlier studies that a satisfactory 5-year patency rate and a gratifying limb salvage rate can be achieved with an extremely low operative mortality rate of 0.37 per cent. Despite the presence of widespread atherosclerotic arterial disease, the 5-year mortality rate is 14.6 per cent, indicating that an attempt at reconstructive surgery is usually well worth while.

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. (J Vasc Surg 2001;33:259-65.)

The use of arm vein in lower-extremity revascularization: Results of 520 procedures performed in eight years

Purpose: The absence of an adequate ipsilateral saphenous vein in patients requiring lower-extremity revascularization poses a difficult clinical dilemma. This study examined the results of the use of autogenous arm vein bypass grafts in these patients. Methods: Five hundred twenty lower-extremity revascularization procedures performed between 1990 and 1998 were followed prospectively with a computerized vascular registry. The arm vein conduit was prepared by using intraoperative angioscopy for valve lysis and identification of luminal abnormalities in 44.8% of cases. Results: Seventy-two (13.8%) femoropopliteal, 174 (33.5%) femorotibial, 29 (5.6%) femoropedal, 101 (19.4%) popliteo-tibial/pedal, and 144 (27.7%) extension “jump” graft bypass procedures were performed for limb salvage (98.2%) or disabling claudication (1.8%). The average age of patients was 68.5 years (range, 32 to 91 years); 63.1% of patients were men, and 36.9% of patients were women. Eighty-five percent of patients had diabetes mellitus, and 77% of patients had a recent history of smoking. The grafts were composed of a single arm vein segment in 363 cases (69.8%) and of spliced composite vein with venovenostomy in 157 cases (30.2%). The mean follow-up period was 24.9 months (range, 1 month to 7.4 years). Overall patency and limb salvage rates for all graft types were: primary patency, 30-day = 97.0% ± 0.7%, 1-year = 80.2% ± 2.1%, 3-year = 68.9% ± 3.6%, 5-year = 54.5% ± 6.6%; secondary patency, 30-day = 97.0% ± 0.7%, 1-year = 80.7% ± 2.1%, 3-year = 70.3% ± 3.4%, 5-year = 57.5% ± 6.2%; limb salvage, 30-day = 97.6% ± 0.7%, 1-year = 89.8% ± 1.7%, 3-year = 82.1% ± 3.3%, 5-year = 71.5% ± 6.9%. Secondary patency and limb salvage rates were greatest at 5 years for femoropopliteal grafts (69.8% ± 12.8%, 80.7% ± 11.8%), as compared with femorotibial (59.6% ± 10.3%, 72.7% ± 10.5%), femoropedal (54.9% ± 25.7%, 56.8% ± 26.9%,) and popliteo-tibial/pedal grafts (39.0% ± 7.3%, 47.6% ± 15.4%). The patency rate of composite vein grafts was equal to that of single-vein conduits. The overall survival rate was 54% at 4 years. Conclusion: Autogenous arm vein has been used successfully in a wide variety of lower-extremity revascularization procedures and has achieved excellent long- and short-term patency and limb salvage rates, higher than those generally reported for prosthetic or cryopreserved grafts. Its durability and easy accessibility make it an alternative conduit of choice when an adequate saphenous vein is not available. (J Vasc Surg 2000;31:50-9.)

Women have increased risk of perioperative myocardial infarction and higher long-term mortality rates after lower extremity arterial bypass grafting

Purpose: The purpose of this study was to determine the effect of gender on the immediate and long-term postoperative morbidity, mortality, and patency rates for infrainguinal autogenous vein bypass grafts. Methods: Data were abstracted for consecutive patients who were followed in a prospective surveillance protocol after undergoing infrainguinal autogenous vein bypass grafting during the years 1988 to 1994. There were 165 grafts constructed in 148 patients (101 in 87 men, and 64 in 61 women). Gender differences were analyzed with Student t test or χ 2 test for risk factors, indications for reconstruction, and complications. The patency rates and the long-term survival rates were compared by means of life-table analysis. Eagle criteria and long-term survival rates were compared with multivariate analysis. Results: The mean follow-up period was 36 months (39 months for men, and 32 months for women), with a range of 6 to 123 months for the total follow-up period. The two groups did not differ in age at the time of operation (66.6 ± 1.2 years for men, and 66.7 ± 1.5 years for women) or in history of diabetes (48% for men, and 56% for women). The risks were similar for hypertension (48% for men vs 45% women), preoperative myocardial infarction (23% for men vs 26% for women), and previous coronary artery bypass grafting (9% for men vs 8% for women). The thallium stress scintigraphy results showed a diagnosis of proportionately more preoperative defects in men (reversible, 34% vs 18%, P < .05; overall, 75% vs 43%, P < .05). The 30-day limb loss rates (0.9% for men, and 0% for women) and mortality rates (2.2% for men, and 5% for women) were similar. Women had statistically more perioperative myocardial infarctions than did men (6 of 61, 9.8% vs 2 of 101, 2%; P < .05), as was documented with electrocardiography and cardiac isoenzymes. Two of these women died within a 30-day postoperative period. The 3-year primary patency rate was 85% for the men and 88% for the women, and the primary assisted patency rate was 97% for the men and 97% for the women. The secondary patency rate was 98% for the men and 97% for the women. The limb salvage rate was slightly higher for the men than for the women (93% vs 87%), although this was not statistically significant. The 5-year survival rate for women was statistically less than for men, with life-table analysis (58% for men vs 42% for women; P < .05). Conclusion:After distal bypass grafting, men and women have similar rates of patency and limb salvage, but women have a higher incidence rate of perioperative myocardial infarction and a decreased 5-year survival rate. These data suggest that women have unrecognized cardiac disease that affects them adversely in the perioperative period and the long term when compared with men who undergo the same operation. (J Vasc Surg 1999;29:807-13.)

Deep infection of infrapopliteal autogenous vein grafts—Immediate use of muscle flaps in leg salvage

Purpose: The purpose of this study was to determine the efficacy of an aggressive management of infrapopliteal autogenous vein graft infection. Methods: Among 341 consecutive infrapopliteal autogenous vein bypass grafts performed at the Helsinki University Central Hospital, 14 patients (4%) had infragenicular wound infection that involved the vein graft. Six of these patients had graft rupture and bleeding. An extensive débridement was performed in all patients. Seven of the grafts had to be partially removed and replaced. The wound and the graft immediately were covered with local muscle flaps in 4 patients and with free muscle flaps in 10 patients. Results: One patient died, and another patient underwent above-knee amputation as a result of a persistent infection and necrosis of the local muscle flap during the 30-day postoperative period. No graft rupture occurred after the treatment of the infected conduit. Graft occlusion occurred in 4 patients who underwent regrafting because of graft rupture and in 1 patient with an infected intact conduit. One patient underwent amputation 15 months later because of an uncontrollable infection despite a patent graft and a functioning flap. At the 1-month, 6-month, 1-year, and 2-year follow-up periods, the leg salvage rates were 92%, 75%, 55%, and 44%, respectively. At the same intervals, 92%, 92%, 70%, and 70% of the patients survived and 85%, 68%, 34%, and 34% of the patients were alive without the loss of their legs. Conclusion: Radical surgical débridement and immediate muscle flap coverage seem to offer an effective alternative method to preserve an infected infrapopliteal autogenous vein graft and to achieve leg salvage. Poor results are expected when a regrafting procedure is necessary for the rupture of an infected vein graft. (J Vasc Surg 1998;28:611-6.)

Inhibition of Myointimal Proliferation by Octreotide in Canine Vein Interposition Grafts

Purpose: The aim of this study was to evaluate the efficacy of octreotide in modulating the progression of intimal hyperplasia in autogenous vein bypass grafts in a canine model. The effect of the drug on the progression of intimal hyperplasia was measured with the Gilman parameter, a measure used extensively as a wound-healing descriptor. Methods: 12 mongrel dogs were randomly and equally divided into two groups. The first group (octreotide group) was administered octreotide 20 µg/kg/day. The control group (group II) received saline solution by subcutaneous injection. Each dog had 8- to 10-cm segments of autogenous jugular vein bypassed to the femoral arteries. Quantitative data on luminel narrowing over time from intimal hyperplasia were compared from calculated Gilman parameters after image analysis of retrieved, histologically processed graft sections. Each vein graft was analyzed by computerized morphometric analysis. Results: The mean Gilman parameter for distal graft segments was 0.47 ± 0.17 mm in the control group and 0.25 ± 0.07 mm in the octreotide group 6 weeks after operation (p < 0.05). Distal graft segments between the control and octreotide groups were statistically significant. In proximal, medial and distal graft segments, the mean Gilman parameters were 0.51 ± 0.16 mm in the control group and 0.37 ± 0.18 mm in the octreotide group, the difference being statistically significant (p < 0.01). Conclusion: Octreotide significantly inhibits myointimal thickening, and these data support the efficacy of octreotide in reducing intimal hyperplasia in arterialized vein grafts during the short postoperative period. Further investigations are required to as certain whether this beneficial effect of octretide persists in the long term.

Preferred strategies for secondary infrainguinal bypass: lessons learned from 300 consecutive reoperations.

To determine the optimal surgical strategies in reoperative infrainguinal bypass, we reviewed our results in 300 consecutive secondary bypasses in 251 patients operated on between Jan. 1, 1975, and Nov. 1, 1993. There were 168 men (67%) and 83 women (33%), with a mean age of 64.8 years and a typical distribution of risk factors including smoking (76.4%), diabetes (33.7%), and coronary artery disease (47.1%). The indications for surgery were limb-threatening ischemia in 83.5% and severe claudication in 16.5% of patients. The majority of conduits (n = 213) were autogenous vein and were composed of a single segment of greater saphenous vein in 121 bypasses (57%) and various alternative veins including composite, arm, and lesser saphenous vein in 92 bypasses (43%). Prosthetic conduits included 69 polytetrafluoroethylene, 16 umbilical vein, and two Dacron grafts. There was one perioperative death (0.3%) and a 25% total morbidity rate including a 1.7% myocardial infarction rate. There was a 28.6% early (< 30 days) graft failure and 10.7% early amputation rate for prosthetic bypass grafts compared with 13.6% early graft failure and 5.6% early amputation rates for vein grafts. Autogenous vein bypasses had higher 5-year secondary patency rates than had prosthetic grafts (51.5% +/- 4.6% vs 27.4% +/- 6.1%, p < 0.001). Results with autogenous vein bypass improved significantly from the 1975 to 1984 to the 1985 to 1993 interval with 5-year secondary patency rates increasing from 38.3% +/- 6.9% to 59.1% +/- 5.8% (p = 0.017) and 5-year limb-salvage rates increasing from 40.4% +/- 7.6% to 72.4% +/- 6.6% (p < 0.001). Vein grafts to the popliteal and tibial outflow levels had equivalent long-term results. Vein grafts completed for claudication demonstrated results superior to those for limb salvage, with a 5-year secondary patency rate of 75.8% +/- 8.1% versus 52.3% +/- 7.9% (p = 0.048). Secondary autogenous vein bypass grafting performed after early primary graft failure (< 3 months) did particularly poorly, with only a 27.2% +/- 7.7% 4-year secondary patency rate. Greater saphenous veins tended to perform better than alternative vein bypasses, with a 5-year secondary patency rate of 68.5% +/- 6.0% compared with 48.3% +/- 10.5% (p = 0.09) and a 5-year limb-salvage rate of 77.8% +/- 7.4% versus 54.2% +/- 11.8% (p = 0.046). When patients suffer a recurrence of limb-threatening ischemia at the time of infrainguinal graft failure, aggressive attempts at secondary revascularization with autogenous vein are warranted based on the low surgical morbidity and mortality rates and the improved patency and limb salvage rates that are currently attainable.

Limb arterial injuries associated with limb fractures: Clinical presentation, assessment and management

Review of limb arterial injuries associated with limb fractures. Retrospective study. University Hospital. The clinical presentation, assessment and management of 25 patients with upper (seven) and lower (18) limb arterial injuries associated with limb bone fractures has been retrospectively reviewed. Five patients presented with life threatening injuries and classic signs of acute limb ischaemia, 15 patients had an obvious limb arterial injury, and 5 presented with a suspected limb arterial injury. The site of arterial damage was: superficial femoral (4); popliteal (11); tibioperoneal trunk (3); anterior tibial (4); posterior tibial (3); peroneal (2); axillary (1); brachial (5); radial (4); and ulnar artery (4). The types of arterial repair were: autogenous vein interposition or bypass grafting (17); P.T.F.E. (2); end-to-end anastomosis (14); and ligation (8). The popliteal vein was injured in six cases, repaired in four and ligated in two; the superficial femoral vein was injured in four cases, repaired in three and ligated in one; and the axillary vein was injured in one case and was ligated. Primary nerve repair was employed in six out of seven injured nerves. Skeletal fixation preceded vascular repair in 21 patients and in four a Javid shunt was used. Intraoperative fasciotomy was performed in 12 out of 18 patients with lower limb ischaemia. Completion arteriography revealed residual thrombi in the distal foot of four patients, in whom intraarterial thrombolysis was effective. During the follow-up period of 1.5 to 2 years, the upper and lower limb preservation rate was 100 and 89%, respectively. The upper limb function was judged excellent in five patients, good in one and fair in one. In the lower limbs it was excellent in 11 patients, good in three, fair in one and poor in one. To ensure life and functional limb salvage of patients with devastating vascular injuries, a well organised multidisciplinary approach is necessary.

Below-Elbow Joint Arterial Reconstruction for Chronic Ischaemia

Ten below-elbow joint arterial bypass grafts performed in nine patients for chronic upper extremity ischaemia are reviewed. The cause of the ischaemia was thromboangiitis obliterans in four patients, iatrogenic trauma in four and unknown aetiology in one. Graft revision was required in two patients with thromboangiitis obliterans who underwent axillary-brachial bypass. Eight grafts, including one reoperation, have remained patent from 1 to 10 years (mean 54.3 months). Graft failure after 5 months did not occur, at which time the primary patency rate was 80%. In general, the long-term patency rates of autogenous vein bypass graft to the forearm were satisfactory. Aggressive arterial reconstruction is especially indicated in significant chronic upper extremity ischaemia resulting from iatrogenic trauma, as chances of success are excellent. Clinical and technical problems of in situ vein bypass in the upper extremity are discussed.

Allograft vein bypass: Is it an acceptable alternative for infrapopliteal revascularization?

Purpose: Autogenous vein bypass grafts to infrapopliteal outflow sites have patency and limb salvage rates significantly superior to those obtained with prosthetic grafts. However, when infrageniculate bypass is required for limb-threatening ischemia in the patient lacking suitable autogenous veins, nonautogenous reconstruction or primary amputation are the only other alternatives.Methods: During a 2-year period we implanted 25 cryopreserved allograft saphenous vein bypass grafts in 24 patients (median age 76 years) with tissue necrosis (20 patients), rest pain (4 patients), or acute ischemia (1 patient); 16 patients were men and 8 were women. As many as six previous revascularizations were performed in 79%; two grafts extended to the infrageniculate popliteal artery; 23 grafts extended to a paramalleolar vessel.Results: Secondary patency at 1 month was 87%, but only 36% at 1 year. Use of warfarin (Coumadin) failed to improve the patency rate (five of nine occlusions treated with Coumadin versus eight of 16 not treated with Coumadin). Only eight of 24 patients are alive with open grafts; nine patients have died.Conclusions: Unheralded occlusions more typical of prosthetic graft failure tempered the initial enthusiasm and effectiveness of vein allografts. All autogenous options must be exhausted to complete distal, secondary revascularization before resorting to nonautogenous conduits. Use of allograft veins must be viewed with continued skepticism.