Polytetrafluoroethylene femorotibial bypass grafting: 5-year patency and limb salvage

Five-year outcomes of the GORE VIABAHN Endoprosthesis for the treatment of complex femoropopliteal lesions from a Japanese postmarket surveillance study

Introduction: The safety and effectiveness of the GORE VIABAHN Endoprosthesis for treatment of symptomatic patients with peripheral artery disease (PAD) and complex femoropopliteal (FP) lesions was assessed in a real-world Japanese practice setting. Methods: A prospective, multicenter, postmarket surveillance study was conducted from 2016 to 2017 at 64 sites in Japan. Symptomatic patients with PAD and FP lesions ⩾ 10 cm and reference vessel diameters ranging from 4.0 to 7.5 mm were eligible for enrollment. Outcome measures evaluated at 5 years were primary patency (PP), primary-assisted patency (PAP), secondary patency (SP), freedom from target lesion revascularization (fTLR), occurrence of device- or procedure-related serious adverse events (SAEs), and stent fractures. Results: A total of 321 patients were enrolled and were a mean age of 73.9 ± 8.7 years; 77.3% were men and 26.5% had chronic limb-threatening ischemia (CLTI). The mean lesion length was 23.6 ± 6.6 cm and the frequency with TASC II C/D lesions and chronic total occlusions was 86.6% and 70.4%, respectively. The Kaplan-Meier estimated PP, PAP, SP, and fTLR at 5 years was 62.4%, 74.1%, 82.3%, and 75.9%, respectively. The mean ankle-brachial index was 0.92 ± 0.15 and the mean improvement in Rutherford class was 2.3 ± 1.4, which was maintained through 5 years. The rate of cumulative device- or procedure-related SAEs through 5 years was 19.9% with only 9.3% of those occurring after the first year. No stent fractures were observed through 5 years by x-ray evaluation. Conclusion: The 5-year safety and efficacy outcomes of the endoprosthesis were clinically acceptable for treating complex FP lesions in a real-world cohort of Japanese patients with PAD. (ClinicalTrials.gov Identifier: NCT04706273).

Short-term patency of iliofemoral to tibial bypass with vascular allografts in a minority population: A retrospective analysis of a single center acute care facility

OBJECTIVE

The aim of this study was to examine the short-term patency rates and associated factors of open lower limb, iliofemoral to tibial bypass using cryopreserved saphenous vein (CSV) in a minority population at an acute care hospital in New York City.

METHODS

A retrospective analysis of patients undergoing infra-inguinal bypass from iliofemoral vessels to tibial arteries with CSV between March 2020-April 2022 at an acute care facility (Harlem Hospital Center, Harlem, New York) was performed. Data including patient demographics, comorbidities, type of operation, follow-up surveillance, and salvage procedures were collected. Results were presented in patency line graphs and a life table. Target limb revascularization (TLR) and amputation free survival (AFS) were also calculated.

RESULTS

Eleven bypass procedures were included in the analysis. Patients were followed for a mean of 10.8 months. Cumulative primary patency rates at 1, 6, and 12 months were 72.7%, 54.5%, and 40.9%, respectively. TLR was 36.4% and the AFS was 66.67% at the mean 10.8-month follow-up.

CONCLUSIONS

The patency rates of minority patients undergoing bypass with CSV were analyzed with creation of a life table and calculation of patency rates, TLR and AFS. The short-term primary patency rates and post-operative outcomes were found to be comparable to larger studies in non-minority cohorts. These results suggest that larger studies as well as prospective analyses and randomized controlled trials in this patient cohort and demographic are needed, as well as optimal selection of patients to determine true clinical implications.

Fresh cold-stored vascular allografts in subgenicular location: Our experience with rescue endovascular techniques

OBJECTIVE

Critical limb ischemia (CLI) is considered the most severe pattern of peripheral artery disease. CLI is associated with high rates of morbidity and mortality and a high risk of limb amputation. In the absence of appropriate autologous grafts, unsuitability of prosthetic bypasses and endovascular methods, fresh cold-stored venous allografts is an option. Endovascular interventional methods are essential methods for maintaining primary and secondary patency.

METHODS

A single-centre retrospective analysis of 82 surgical revascularizations using allogeneic vascular grafts and rescue endovascular techniques restoring and maintaining the patency of these allogeneic revascularizations in the period between 7/2005 and 7/2021.

RESULT

We have performed 82 allogeneic revascularizations in 75 patients (52 reconstructions in men /63.4%/, 30 reconstructions in women /36.6%/). The median age of patients was 68 years (49 min, 87 max). We subsequently had to intervene a total of 26 bypasses. We intervened in 30 acute occluded allogeneic bypass grafts and 9 failing stenotic bypass grafts. We performed 52 angiographies. The success rate of rescue endovascular procedures in primary allogeneic reconstruction with distal anastomosis to the popliteal artery is statistically significant (p <0.02) compared to procedures with distal anastomosis to the tibial and pedal bed. The cumulative patency (primary at time) of allogeneic reconstructions in our group was 89% after 1 month, 51.9% after 12 months, 24.2% after 3 years, 9.8% after 5 years. Limb salvage was 72.6% in 1 year, 53% in 3 years, 36.5% in 5 years, respectively.

CONCLUSION

Cold-stored venous allografts may be used for performing below-the-knee revascularization for CLI with acceptable results despite poor long-term patency. Rescue endovascular techniques are an essential method for restoring or maintaining the patency of these reconstructions. These techniques have a high success rate and no other alternative.

Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia

GUIDELINE SUMMARY

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Global vascular guidelines on the management of chronic limb-threatening ischemia

Chronic limb-threatening ischemia (CLTI) is associated with mortality, amputation, and impaired quality of life. These Global Vascular Guidelines (GVG) are focused on definition, evaluation, and management of CLTI with the goals of improving evidence-based care and highlighting critical research needs. The term CLTI is preferred over critical limb ischemia, as the latter implies threshold values of impaired perfusion rather than a continuum. CLTI is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or a lower limb ulceration >2 weeks duration. Venous, traumatic, embolic, and nonatherosclerotic etiologies are excluded. All patients with suspected CLTI should be referred urgently to a vascular specialist. Accurately staging the severity of limb threat is fundamental, and the Society for Vascular Surgery Threatened Limb Classification system, based on grading of Wounds, Ischemia, and foot Infection (WIfI) is endorsed. Objective hemodynamic testing, including toe pressures as the preferred measure, is required to assess CLTI. Evidence-based revascularization (EBR) hinges on three independent axes: Patient risk, Limb severity, and ANatomic complexity (PLAN). Average-risk and high-risk patients are defined by estimated procedural and 2-year all-cause mortality. The GVG proposes a new Global Anatomic Staging System (GLASS), which involves defining a preferred target artery path (TAP) and then estimating limb-based patency (LBP), resulting in three stages of complexity for intervention. The optimal revascularization strategy is also influenced by the availability of autogenous vein for open bypass surgery. Recommendations for EBR are based on best available data, pending level 1 evidence from ongoing trials. Vein bypass may be preferred for average-risk patients with advanced limb threat and high complexity disease, while those with less complex anatomy, intermediate severity limb threat, or high patient risk may be favored for endovascular intervention. All patients with CLTI should be afforded best medical therapy including the use of antithrombotic, lipid-lowering, antihypertensive, and glycemic control agents, as well as counseling on smoking cessation, diet, exercise, and preventive foot care. Following EBR, long-term limb surveillance is advised. The effectiveness of nonrevascularization therapies (eg, spinal stimulation, pneumatic compression, prostanoids, and hyperbaric oxygen) has not been established. Regenerative medicine approaches (eg, cell, gene therapies) for CLTI should be restricted to rigorously conducted randomizsed clinical trials. The GVG promotes standardization of study designs and end points for clinical trials in CLTI. The importance of multidisciplinary teams and centers of excellence for amputation prevention is stressed as a key health system initiative.

Dehydration improves biomechanical strength of bioartificial vascular graft material and allows its long-term storage

Introduction

We have recently reported about a novel technique for the generation of bioartificial vascular grafts based on the use of a compacted fibrin matrix. In this study, we evaluated the effects of a dehydration process on the biomechanical properties of compacted fibrin tubes and whether it allows for their long-term storage.

Materials and methods

Fibrin was precipitated from fresh frozen plasma by means of cryoprecipitation and simultaneously with a thrombin solution applied in a high-speed rotating casting mold. Subsequent dehydration of the fibrin tubes (29/38) was performed in dry air with a dilator inside the tube to prevent the collapse of the lumen. Dehydrated fibrin tubes were stored for six (n=9) and 12 months (n=10) at room temperature. Comparative analysis was done on initially generated and dehydrated fibrin tubes before and after storage to evaluate the effects of the dehydration process and storage on the biomechanical properties and structure of the tubes.

Results

Thirty-eight fibrin tubes were generated by high-speed rotation-molding from 142±3 mg fibrinogen with an inner diameter of 5.8±0.1 mm and a length of 100 mm. A centrifugal force of nearly 900×g compacted applied fibrin, while fluid was pressed out of the matrix and drained from the mold via holes resulting in a 16-fold compaction of the fibrin matrix. Dehydration was characterized by shrinkage of the tubes to a diameter of 3.2±0.2 mm, while the length remained at 100 mm equivalent to a further two-fold compaction. The biomechanical strength of the dehydrated fibrin tubes significantly increased to values comparable to that of native ovine carotid arteries and maintained during the first 6 months of storage. After 12 months of storage, only five of 10 tubes were intact, and only one showed maintained biomechanical strength.

Discussion

Compaction of a fibrin matrix in high-speed rotation-moulding and subsequent dehydration enables for the construction of small-caliber fibrin grafts. Over and above, the dehydration process allows their storage and stockpiling as a prerequisite for clinical use.

Current Status of Arterial Revascularization for the Treatment of Critical Limb Ischemia in Infrainguinal Atherosclerotic Disease

Critical limb ischemia (CLI) is the most severe form of peripheral arterial disease (PAD) that may result in limb loss and even death; thus, the fast and proper treatment should be employed as earlier as possible to prevent these catastrophic consequences. Arterial revascularization is almost always an indispensable treatment option for CLI. Although both endovascular and surgical revascularization procedures have an important role, nowadays, the hybrid revascularization as a combination of these revascularization procedures has also gained increasing popularity in the treatment of patients with CLI. This review provides an update on the arterial revascularization strategies for the treatment of CLI.

Critical Limb Ischemia: An Expert Statement

Critical limb ischemia (CLI), the most advanced form of peripheral artery disease, is associated with significant morbidity, mortality, and health care resource utilization. It is also associated with physical, as well as psychosocial, consequences such as amputation and depression. Importantly, after a major amputation, patients are at heightened risk of amputation on the contralateral leg. However, despite the technological advances to manage CLI with minimally invasive technologies, this condition often remains untreated, with significant disparities in revascularization and amputation rates according to race, socioeconomic status, and geographic region. Care remains disparate across medical specialties in this rapidly evolving field. Many challenges persist, including appropriate reimbursement for treating complex patients with difficult anatomy. This paper provides a comprehensive summary that includes diagnostic assessment and analysis, endovascular versus open surgical treatment, regenerative and adjunctive therapies, and other important aspects of CLI.

Development of an in vivo tissue-engineered vascular graft with designed wall thickness (biotube type C) based on a novel caged mold

Small-diameter biotube vascular grafts developed by in-body tissue architecture had high patency at implantation into rabbit carotid arteries or rat abdominal aortas. However, the thin walls (34 ± 14 μm) of the original biotubes made their implantation difficult into areas with low blood flow volumes or low blood pressure due to insufficient mechanical strength to maintain luminal shape. In this study, caged molds with several windows were designed to prepare more robust biotubes. The molds were assembled with silicone tubes (external diameter 2 mm) and cylindrical covers (outer diameter 7 mm) with 12 linear windows (1 × 9 mm). After the molds were embedded into beagle dorsal subcutaneous pouches for 4 weeks, type C (cage) biotubes were obtained by completely extracting the surrounding connective tissues from the molds and removing the molds. The biotube walls (778 ± 31 μm) were formed at the aperture (width 1 mm) between the silicone rods and the covers by connective cell migration through the windows of the covers. Excellent mechanical properties (external pressure resistance, approximately 4 times higher than beagle native femoral arteries; burst strength, approximately 2 times higher than original biotubes) were obtained. In the acute phase of implantation of the biotubes into beagle femoral arteries, perfect patency was obtained with little stenosis and no aneurysmal dilation. The type C biotubes may be useful for implantation into peripheral arteries or veins in addition to aortas.

Comparison of surgical bypass with angioplasty and stenting of superficial femoral artery disease

OBJECTIVE

To evaluate the contemporary outcome of femoral-popliteal bypass compared with angioplasty and stenting in patients with symptomatic peripheral arterial disease (PAD) in terms of patency and reintervention rates.

METHODS

We identified all patients evaluated at the Johns Hopkins Bayview Medical Center with the presumptive diagnosis of PAD from September 2005 to September 2010. In this group, we selected all symptomatic patients after failing medical management who received percutaneous transluminal angioplasty/stenting of the superficial femoral artery or femoral-popliteal bypass. We compared the overall patency and reintervention rates between the two groups as well as patency within TransAtlantic Inter-Society Consensus (TASC) II subgroups. Descriptive analyses were performed using χ(2) and two-sided t-tests. The Mann-Whitney U test was used to compare distributions of continuous variables and the Fisher exact test for categorical variables. Cox proportional hazard model was used to examine the treatment effect within each lesion type, using bypass as the reference group.

RESULTS

Out of 1237 patients evaluated at Johns Hopkins Bayview Medical Center for PAD from September 2005 to September 2010, we identified 104 symptomatic patients who received percutaneous transluminal angioplasty/stenting of the superficial femoral artery or femoral-popliteal bypass after failing medical management. There were 61 male patients (56%), and the mean age was 68 years in both groups. Both treatment groups had similar risk factors. Overall, 77% of patients with TASC II A and B lesions underwent angioplasty and stenting, whereas 73% of patients with TASC C and D lesions underwent bypass (P < .01). The primary patency at 24 months was better for the stent group 67% (95% confidence interval [CI], 0.52-0.78) vs bypass group 49% (95% CI, 0.32-0.64; P = .05). The rate of reintervention within the 2-year period was higher in the bypass group compared with the stent group (54% vs 31%; P = .02). TASC A and B lesions combined demonstrated a reduced hazard of patency failure compared with TASC C or D lesions combined (hazard ratio, 2.42; 95% CI, 1.26, 4.65; P < .01).

CONCLUSIONS

This is the first study that documents higher reintervention rates for femoral-popliteal bypass compared with angioplasty and stenting. We believe that the main reason for this finding is the fact that the bypass patients had significantly more advanced disease. This, emphasizes that one must consider the patient population undergoing intervention when comparing revascularization procedures. A prospective randomized trial is needed to determine the overall better treatment option.

Basic data related to surgical infrainguinal revascularization procedures: a twenty year update

In 1990, Dalman and Taylor published a compilation of reported data that were identified by them as related to infrainguinal revascularization procedures in peripheral vascular surgery during the decade of the 1980s. The intervening 20 years has seen revolutionary advances in the field of peripheral vascular surgery, especially in the adoption of endovascular techniques, and an explosion of data related to emerging technologies in the field of infrainguinal revascularization. The tables in this manuscript reflect the evolution of our surgical knowledge during the turn of the 21st century. The superior patency of autologous saphenous vein in all positions is reaffirmed.

Trends and outcomes after surgical lower limb revascularization in England

Background

The aim was to analyse contemporary data on the number of surgical revascularization procedures performed each year in England, and their outcome.

Methods

Hospital Episode Statistics and Office for National Statistics data were used to quantify numbers and identify factors associated with outcome after all femoropopliteal and femorodistal bypass procedures performed between 2002 and 2006. Outcome measures were repeat bypass, major amputation, death and a composite measure. Single-level multivariable logistic regression modelling was used to quantify the effect of these variables on outcome.

Results

A total of 21 675 femoropopliteal and 3458 femorodistal bypass procedures were performed. Mean in-hospital mortality rates were 6·7 and 8·0 per cent respectively. One-year survival rates were 82·8 and 79·1 per cent; both increased over the study interval. The mean 1-year major amputation rate after femoropopliteal bypass was 10·4 per cent, which decreased significantly over the 5 years (P &lt; 0·001); after distal bypass the rate of 20·8 per cent remained unchanged (P = 0·456). Diabetes mellitus and chronic kidney disease were significant predictors of adverse outcome for both procedures: odds ratio (OR) at 1 year 1·56 (95 per cent confidence interval 1·46 to 1·67; P &lt; 0·001) and 2·15 (1·88 to 2·45; P &lt; 0·001) respectively for femoropopliteal bypass. Previous femoral angioplasty was associated with an increased rate of major amputation 1 year after proximal bypass (OR 1·18, 1·05 to 1·33; P = 0·004).

Conclusion

Although all mortality rates are improving, the major amputation rate remains high after femorodistal bypass. Adverse events occurred after 37·6 per cent of femoropopliteal and 49·7 per cent of femorodistal bypasses; diabetes and chronic renal failure were the main predictors of poor outcome.

Long-term outcome of infrapopliteal catheter-based intervention for critical limb ischemia

CONTEXT

Percutaneous treatment of tibioperoneal occlusive disease is associated with decreased morbidity compared with bypass surgery. The long-term patency and limb salvage rates are not well documented.

AIMS

To evaluate the long-term outcome of endoluminal interventions for tibioperoneal lesions.

METHODS

A retrospective study was performed to determine the outcomes of patients undergoing infrapopliteal catheter-based intervention for critical limb ischemia. Collected data included demographics, comorbidities, clinical presentation, pre- and postintervention noninvasive vascular measurements (segmental pressure and waveforms, and ankle-brachial index [ABI]), type of intervention, limb loss rate, patient follow-up and need for surgical revascularization. Statistical analysis was performed with the two-tailed t test. P<0.05 was considered significant; results were reported as mean ± SD. Cox regression analysis and Kaplan-Meier limb survival analysis were performed to demonstrate freedom from amputation over time.

RESULTS

Thirty-five patients underwent intervention from 2003 to 2008; technical success was achieved in 26 patients (75%). Arterial segmental pressure studies revealed a significant increase in ABI - preprocedure ABI was 0.62±0.24 versus a postintervention ABI of 0.81±0.29 (P=0.02). The limb salvage rate was 63% during the follow-up period. Limb salvage was better for patients who underwent isolated infrapopliteal intervention versus combined above and below the knee intervention.

CONCLUSION

Percutaneous interventions for tibioperoneal occlusive disease offer an acceptable limb salvage rate and may be the preferred initial treatment for critical limb ischemia.

Critical limb ischemia: medical and surgical management

Abstract

Chronic critical limb ischemia (CLI), defined as > 2 weeks of rest pain, ulcers, or tissue loss attributed to arterial occlusive disease, is associated with great loss of both limb and life. Therapeutic goals in treating patients with CLI include reducing cardiovascular risk factors, relieving ischemic pain, healing ulcers, preventing major amputation, improving quality of life and increasing survival. These aims may be achieved through medical therapy, revascularization, or amputation. Medical therapy includes administration of analgesics, local wound care and pressure relief, treatment of infection, and aggressive therapy to modify atherosclerotic risk factors. For patients who are not candidates for revascularization, and who are unwilling or unable to undergo amputation, treatments such as intermittent pneumatic compression or spinal cord stimulation may offer symptom relief and promote wound healing. Revascularization offers the best option for limb salvage. The decision to perform surgery, endovascular therapy, or a combination of the two modalities (‘hybrid’ therapy) must be individualized. Patients who are relatively fit and able to withstand the rigors of an open procedure may benefit from the long-term durability of surgical repair. In contrast, frail patients with a limited life expectancy may experience better outcomes with endovascular reconstruction. Hybrid therapy is an attractive option for patients with limited autologous conduit, as it permits complete revascularization with a less extensive procedure, shorter duration of operation, and decreased risk of peri-operative complications. Amputation should be considered for patients who are non-ambulatory, demented, or unfit to undergo revascularization.

Shifting paradigms in the treatment of lower extremity vascular disease: a report of 1000 percutaneous interventions

OBJECTIVES

Catheter-based revascularization has emerged as an alternative to surgical bypass for lower extremity vascular disease and is a frequently used tool in the armamentarium of the vascular surgeon. In this study we report contemporary outcomes of 1000 percutaneous infra-inguinal interventions performed by a single vascular surgery division.

METHODS

We evaluated a prospectively maintained database of 1000 consecutive percutaneous infra-inguinal interventions between 2001 and 2006 performed for claudication (46.3%) or limb-threatening ischemia (52.7%; rest pain in 27.7% and tissue loss in 72.3%). Treatments included angioplasty with or without stenting, laser angioplasty, and atherectomy of the femoral, popliteal, and tibial vessels.

RESULTS

Mean age was 71.4 years and 57.3% were male; comorbidities included hypertension (84%), coronary artery disease (51%), diabetes (58%), tobacco use (52%), and chronic renal insufficiency (39%). Overall 30-day mortality was 0.5%. Two-year primary and secondary patencies and rate of amputation were 62.4%, 79.3%, and 0.5%, respectively, for patients with claudication. Two-year primary and secondary patencies and limb salvage rates were 37.4%, 55.4%, and 79.3% for patients with limb-threatening ischemia. By multivariable Cox PH modeling, limb-threat as procedural indication (P < 0.0001), diabetes (P = 0.003), hypercholesterolemia (P = 0.001), coronary artery disease (P = 0.047), and Transatlantic Inter-Society Consensus D lesion complexity (P = 0.050) were independent predictors of recurrent disease. For patients that developed recurrent disease, 7.5% required no further intervention, 60.3% underwent successful percutaneous reintervention, 11.7% underwent bypass and 20.5% underwent amputation. Patency rates were identical for the initial procedure and subsequent reinterventions (P = 0.97).

CONCLUSION

Percutaneous therapy for peripheral vascular disease is associated with minimal mortality and can achieve 2-year secondary patency rates of nearly 80% in patients with claudication. Although patency is diminished in patients with limb-threat, limb-salvage rates remain reasonable at close to 80% at 2 years. Percutaneous infra-inguinal revascularization carries a low risk of morbidity and mortality, and should be considered first-line therapy in patients with chronic lower extremity ischemia.

The mechanical properties of infrainguinal vascular bypass grafts: their role in influencing patency

When autologous vein is unavailable, prosthetic graft materials, particularly expanded polytetrafluoroethylene are used for peripheral arterial revascularisation. Poor long term patency of prosthetic materials is due to distal anastomotic intimal hyperplasia. Intimal hyperplasia is directly linked to shear stress abnormalities at the vessel wall. Compliance and calibre mismatch between native vessel and graft, as well as anastomotic line stress concentration contribute towards unnatural wall shear stress. High porosity reduces graft compliance by causing fibrovascular infiltration, whereas low porosity discourages the development of an endothelial lining and hence effective antithrombogenicity. Therefore, consideration of mechanical properties is necessary in graft development. Current research into synthetic vascular grafts concentrates on simulating the mechanical properties of native arteries and tissue engineering aims to construct a new biological arterial conduit.

Contemporary Series of Morbidity and Mortality after Lower Limb Amputation

OBJECTIVES

This study was performed in order to assess morbidity and mortality associated with major lower extremity amputation according to an extensive complication registration system used in our hospital.

METHODS

All consecutive patients who underwent lower limb major extremity amputation were included from January 1996 until December 2002. Complications were prospectively registered according to our standard complication registration system.

RESULTS

In 97 patients 122 amputations were performed including 45 above (AKA) and 77 below (BKA) knee amputations. The conversion rate from below to above knee amputation was 14%. In 65 patients 107 complications occurred (67%). The incidence of wound infection was 10% in the BKA group and 2% in the AKA group. The most frequently reported complications were pressure sores (8%) or originating from the urinary tract (13%). The hospital mortality for BKA was 9% and for AKA 18%. Long-term survival was 62% at 1 year, 50% at 2 years and 29% at 5 years.

CONCLUSIONS

An extensive registration system provides us with a detailed insight into the incidence, consequence and cause of complications. Major lower extremity amputations are still associated with considerable morbidity and mortality.

Limb salvage after infrainguinal bypass graft failure

OBJECTIVE

The purpose of this study was to examine the outcome of patients in whom an infrainguinal bypass graft failed.

METHODS

This was a retrospective analysis of consecutive patients undergoing infrainguinal bypass grafting in a single institution over 8 years.

RESULTS

Six hundred thirty-one infrainguinal bypass grafts were placed in 578 limbs in 503 patients during the study period. The indication for surgery was limb-threatening ischemia in 533 patients (85%); nonautologous conduits were used in 259 patients (41%), and 144 (23%) were repeat operations. After a mean follow-up of 28 +/- 1 months (median, 23 months; range, 0-99 months), 167 grafts (26%) had failed secondarily. The rate of limb salvage in patients with graft failure was poor, only 50% +/- 5% at 2 years after failure. The 2-year limb salvage rate depended on the initial indication for bypass grafting: 100% in patients with claudication (n = 16), 55% +/- 8% in patients with rest pain (n = 49), and 34% +/- 6% in patients with tissue loss (n = 73; P <.001). The prospect for limb salvage also depended on the duration that the graft remained patent. Early graft failure (<30 days; n = 25) carried a poor prognosis, with 2-year limb salvage of only 25% +/- 10%; limb salvage was 53% +/- 5% after intermediate graft failure (<2 years, n = 110) and 79% +/- 10% after late failure (>2 years, n = 15; P =.04). Multivariate analysis revealed shorter patency interval before failure (P =.006), use of warfarin sodium (Coumadin) postoperatively (P =.006), and infrapopliteal distal anastomosis (P =.01) as significant predictors for ultimate limb loss.

CONCLUSION

The overall prognosis for limb salvage in patients with failed infrainguinal bypass grafts is poor, particularly in patients with grafts placed because of tissue loss and those with early graft failure.