Femorodistal Bypass Research Articles

Treatment of Popliteal Artery Aneurysms by Means of Cryopreserved Homograft

Autologous saphenous vein is considered the gold standard conduit in the femoral-popliteal revascularization for popliteal artery aneurysms (PAAs). In several cases, it may be absent or unsuitable for length or diameter and so it may be considered unfit for a conduit. In such patients, a synthetic graft or the endovascular correction can be useful, but results are controversial. In this retrospective case series, we have analyzed the safety and efficacy of the cryopreserved homograft (CHg) as a conduit in the PAA revascularization. In the period between January 2005 and December 2013, 54 PAAs have been treated with an arterial CHg. Indications to surgery were asymptomatic aneurysm with >25-mm diameter in 30 cases (55.6%), ischemic symptoms in 20 (37%), and compressive symptoms in 4 (7.4%). An urgent treatment was performed in 8 cases (14.8%) for severe ischemic symptoms. All cases have been operated by the same vascular team: a posterior surgical approach was preferred whenever possible (33 cases, 61.1%). All patients received a clinical and radiologic follow-up, and all data were collected in a specific database. A >10-mm diameter increase of the conduit was considered significant for an aneurysmatic degeneration. The primary outcomes were complications and reoperation rate, limb salvage, and primary and secondary patency. Secondary outcome was the incidence of aneurysmatic degeneration of the CHg. Mean diameter of the homografts was 6.3 mm (range, 4-8 mm). In the 30-day postoperative period, 7 PAAs (13%) developed a complication: 3 wound infections, 3 graft thrombosis, and 1 anastomotic bleeding. Six cases needed a reoperation: 2 surgical revascularizations, 2 wound debridement, and 1 anastomotic hemostasis; 1 major amputation was necessary for graft failure after the revascularization. Mean follow-up was 34.8 months (range, 1-96). Five cases (9.3%) developed a graft complication with 4 reoperations necessary (7.4%): 2 grafts required a percutaneous transluminal angioplasty for a perigraft stenosis and 2 underwent a femorodistal bypass in CHg for severe ischemic symptoms after CHg occlusion. Another one CHg occlusion was treated conservatively because it was clinically asymptomatic. Primary patency was 96.3%, 93.9%, and 88.3% at 12, 36, and 60 months, respectively; secondary patency was 98.1% at 12, 36, and 60 months. Freedom from amputation resulted in 98.1%. No aneurysmatic degeneration was observed. Univariate and multivariate analysis showed urgent surgery to be independent risk factors for complications, reoperations, and CHg occlusion (P < 0.05). In this retrospective study, the use of CHg showed to be safe and effective in the surgery of PAAs, either in the short or in the long-term follow-up. Urgent surgery can be considered predictive of graft failure. In our experience, CHg can be considered a good alternative conduit to the autologous saphenous vein.

Antiplatelet agents for preventing thrombosis after peripheral arterial bypass surgery.

Antiplatelet agents for preventing thrombosis after peripheral arterial bypass surgery.

Resultados del bypass infrainguinal protésico en isquemia crítica: factores asociados a permeabilidad y salvamento de la extremidad

ObjectivesTo assess the outcomes of prosthetic bypass grafts in critical limb ischemia, as well as to determine the predictors of patency and limb salvage. Materials and methodsRetrospective cohort study of patients with critical limb ischemia undergoing a prosthetic infrainguinal bypass graft between 1997 and 2013 in a single centre. The pre- and post-operative data were collected, and the cohort was divided into 3 groups according to the location of the distal anastomosis: Above-knee popliteal artery (POP1), below-knee popliteal artery (POP3), or femorodistal. An assessment was made of the primary patency, assisted primary patency, secondary patency, limb salvage, and survival. Stratified statistical analysis using the Kaplan-Meier for patency, limb salvage and survival. Univariate and multivariate analysis of risk factors associated with the results using Cox regression. ResultsA total of 154 prosthetic graft bypass, divided into POP1 36.4% (n=56), POP3 50% (n=77), and femorodistal 13.6% (n=21). Differences were found in mean age (POP1 68.9 years, POP3 77.2 years, femorodistal 76.8 years; P<.001). Median follow-up was 11 months. The best outcomes were found in POP1, and the worse in femorodistal in terms of patency and limb salvage (Log Rank P1 0.004, P1A 0.001, P2 0.001 and SE 0.025), with no differences in survival time (Log Rank 0.068). Coronary artery disease and femorodistal bypass were independent risk factors in patency and limb salvage. Older patients and those with chronic renal failure had higher mortality rates. ConclusionsProsthetic infrainguinal bypass graft has fairly good outcomes in critical limb ischemia. The worst outcomes may be expected in patients with coronary artery disease and femorodistal bypass.

Investigations of a Thermosensitive Gel to Temporarily Occlude Crural Arteries in Femoro-distal Bypass Surgery

Objectives: Long occlusions in calcified crural arteries are a major cause of endovascular technical failure in patients with critical limb ischaemia. Therefore, distal bypasses are mainly performed in patients with heavily calcified arteries and with consequently delicate clamping. A new reverse thermosensitive polymer (RTP) is an alternative option to occlude target vessels. The aim of the study is to report our technical experience with RTP and to assess its safety and efficiency to temporarily occlude small calcified arteries during anastomosis time. Methods: Between July 2010 and December 2011, we used RTP to occlude crural arteries in 20 consecutive patients with 20 venous distal bypasses. We recorded several operative parameters, such as volume of injected RTP, duration of occlusion and anastomotic time. Quality of occlusion was subjectively evaluated. Routine on-table angiography was performed to search for plug emboli. Primary patency, limb salvage and survival rates were reported at 6 months. Results: In all patients, crural artery occlusion was achieved with the RTP without the use of an adjunct occlusion device. Mean volume of RTP used was 0.3 ml proximally and 0.25 ml distally. Mean duration of occlusion was 14.4 ± 4.5 min, while completion of the distal anastomosis lasted 13.4 ± 4.3 min. Quality of occlusion was judged as excellent in eight cases and good in 12 cases. Residual plugs were observed in two patients and removed with an embolectomy catheter, before we amended the technique for dissolution of RTP. At 6 months, primary patency rate was 75% but limb salvage rate was 87.5%. The 30-day mortality rate was 10%. Conclusions: This study shows that RTP is safe when properly dissolved and effective to occlude small calcified arteries for completion of distal anastomosis.

Volume–Outcome Relationships in Lower Extremity Arterial Bypass Surgery

We sought to investigate whether a volume-outcome relationship exists for lower extremity arterial bypass (LEAB) surgery. All LEAB procedures performed in England between 2002 and 2006 were identified from Hospital Episode Statistics data. A Charlson-type risk profile, including operating hospital annual case volume, was identified per patient. Outcome measures of revision bypass, amputation, death and a composite measure were established during the index admission and at 1 year.Quintile analysis and multilevel multivariate modeling were used to identify the existence of a volume-outcome relationship and allow adjustment of results for significant determinants of outcome. A total of 27,660 femoropopliteal bypass and 4161 femorodistal bypass procedures were identified.As volume increased, in-hospital mortality after popliteal bypass decreased from 6.5% to 4.9% (P = 0.0045), with a corresponding odds ratio of 0.980 [95% confidence interval (CI), 0.929-0.992; P = 0.014] for every increase of 50 patients per year. Major amputation decreased from 4.1% to 3.2% (P = 0.006) in high-volume hospitals, with a reduction in risk of 0.955 (95% CI, 0.928-0.983; P = 0.002) at 1 year.For distal bypass, in-hospital mortality decreased from 9.8% to 5.5% (P = 0.004) and 1-year major amputation decreased from 25.4% to 18.2% (P < 0.001), with a corresponding odds ratio of 0.658 (95% CI, 0.517-0.838; P < 0.0001) as the volume increased.An increase in the chance of revision surgery (10.6% vs 8.2%, P < 0.001) was seen with higher volume, with an increased odds ratio of 1.031 (95% CI, 1.005-1.057; P = 0.018). A positive volume-outcome relationship exists for LEAB procedures even after employing multilevel risk adjustment models. There are benefits in terms of mortality and limb salvage both in the short-term and at 1 year postsurgery.

Investigations of a Thermosensitive Gel to Temporarily Occlude Crural Arteries in Femoro-distal Bypass Surgery

ObjectivesLong occlusions in calcified crural arteries are a major cause of endovascular technical failure in patients with critical limb ischaemia. Therefore, distal bypasses are mainly performed in patients with heavily calcified arteries and with consequently delicate clamping. A new reverse thermosensitive polymer (RTP) is an alternative option to occlude target vessels. The aim of the study is to report our technical experience with RTP and to assess its safety and efficiency to temporarily occlude small calcified arteries during anastomosis time. MethodsBetween July 2010 and December 2011, we used RTP to occlude crural arteries in 20 consecutive patients with 20 venous distal bypasses. We recorded several operative parameters, such as volume of injected RTP, duration of occlusion and anastomotic time. Quality of occlusion was subjectively evaluated. Routine on-table angiography was performed to search for plug emboli. Primary patency, limb salvage and survival rates were reported at 6 months. ResultsIn all patients, crural artery occlusion was achieved with the RTP without the use of an adjunct occlusion device. Mean volume of RTP used was 0.3 ml proximally and 0.25 ml distally. Mean duration of occlusion was 14.4 ± 4.5 min, while completion of the distal anastomosis lasted 13.4 ± 4.3 min. Quality of occlusion was judged as excellent in eight cases and good in 12 cases. Residual plugs were observed in two patients and removed with an embolectomy catheter, before we amended the technique for dissolution of RTP. At 6 months, primary patency rate was 75% but limb salvage rate was 87.5%. The 30-day mortality rate was 10%. ConclusionsThis study shows that RTP is safe when properly dissolved and effective to occlude small calcified arteries for completion of distal anastomosis.

Interposition vein cuff for infragenicular prosthetic bypass graft

The use of prosthetic grafts such as polytetrafluorethylene (PTFE) or Dacron to bypass occluded arteries in the lower leg is an accepted practice in the absence of suitable autologous vein. The aim is limb salvage or functional improvement in critical limb ischaemia, but patency rates for below knee prosthetic bypasses are low. Creating a vein cuff at the distal anastomosis is thought to improve outcomes. Other techniques including the use of pre-cuffed synthetic grafts, spliced segments of vein and the creation of an arterio-venous fistula (AVF) are also used to improve patency. To compare the beneficial effects of using vein cuffed prosthetic grafts for below knee bypass in critical limb ischaemia with other types of reconstruction. The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 2012) and CENTRAL (2012, Issue 5) for publications comparing prosthetic infragenicular bypass using vein cuffs with other bypass techniques. Randomised controlled trials comparing interposition vein cuff prosthetic graft with autologous vein graft and non-cuffed prosthetic graft for infragenicular bypass in patients with critical limb ischaemia were included. Trials comparing vein cuff prosthetic grafts with or without AVF and vein cuff prosthetic grafts with pre-cuffed prosthetic grafts were also included. The trials were selected and assessed independently by two review authors. Six trials with a combined total of 885 patients were included in this review. Only studies using prosthetic PTFE grafts were identified.Two trials compared PTFE graft with or without a vein cuff. In one underpowered trial for below knee bypass the cumulative primary patency rate was statistically significantly higher in the vein cuff group (80.3% versus 65.3% at 12 months and 51.8% versus 29.1% at 24 months, P = 0.03). There was no statistically significant difference in secondary patency (82.9% versus 72.5% and 58.6% versus 34.9%, P = 0.14) and limb salvage rates (86.3% versus 71.8% and 82.6% versus 62.2%, P = 0.08) at 12 and 24 months respectively. The other trial showed no statistically significant difference between the groups at three years in the below knee femoro-popliteal bypasses (primary patency rate 26% (95% confidence interval (CI) 18 to 38) and 43% (95% CI 33 to 58), secondary patency rate 32% (95% CI 23 to 44) and 42% (95% CI 31 to 56) and limb salvage rate 64% (95% CI 54 to 75) and 61% (95% CI 50 to 74) in the collar and no collar groups respectively). In the femoro-distal bypass group, the differences in primary patency, secondary patency and limb salvage rates were also not statistically significant at three years (primary patency rate 20% (95% CI 11 to 38) and 17% (95% CI 9 to 33), secondary patency rate 22% (95% CI 12 to 39) and 20% (95% CI 11 to 35) and limb salvage rate 59% (95% CI 46 to 76) and 44% (95% CI 32 to 61) in the collar and no collar groups respectively).One trial compared pre-cuffed PTFE grafts with vein cuffed grafts. There was no statistically significant difference in primary patency rate (62% pre-cuffed PTFE versus 52% vein cuff PTFE and 49% versus 44%, P = 0.53), secondary patency rate (66% pre-cuffed PTFE versus 53% vein cuff PTFE and 55% versus 50%, P = 0.30) or limb salvage rate (75% pre-cuffed PTFE versus 72% vein cuff PTFE and 62% versus 65%, P = 0.88) at 12 and 24 months respectively.One trial compared spliced vein grafts with vein cuffed PTFE grafts. At 24 months, the secondary patency rate was statistically significantly higher in the spliced vein group (86% in the spliced vein and 52% in the vein cuff group, P < 0.05). There was no statistical significant difference in primary patency rate (44% versus 50%, P > 0.05) and limb salvage rate (94% versus 85%, P > 0.05).Two trials compared vein cuff PTFE grafts with and without AVF. There was no statistical significant difference at 24 months in primary patency rate (29% versus 36%, P = 0.77; 32% versus 28%, P = 0.2), secondary patency rate (40% versus 40%, P = 0.89; 28% versus 24%, P = 0.2) and limb salvage rate (65% versus 70%, P = 0.97; 62% versus 71%, P = 0.3). There is evidence that a vein cuff at the distal anastomosis site improves primary graft patency rates for below knee PTFE graft, but this does not reduce the risk of limb loss. Pre-cuffed PTFE grafts have comparable patency and limb salvage rates to vein cuff PTFE grafts. The use of spliced veins improved secondary patency but this did not translate into improved limb salvage. The use of an AVF alone showed no added benefits. Evidence for a beneficial effect of vein cuffed PTFE grafts is weak and based on underpowered trials. A large study with a specific focus on below knee vein cuff prosthetic grafts, including PTFE, is required.

Single-Center Experience in Endovascular Treatment for Infrainguinal Bypass Obstructions

PurposeTo evaluate patency and clinical efficacy of endovascular therapy for infrainguinal bypass obstructions. Materials and MethodsPatients were categorized with regard to symptoms (asymptomatic/intermittent claudication [IC] vs critical limb ischemia [CLI]), bypass graft material used (autologous vs prosthetic graft), and localization of distal anastomoses (femoropopliteal vs femorodistal bypass). Primary patency was defined as absence of sonographically verified stenosis greater than 50%. Assisted primary patency was applied to secondary revisions to prevent impending occlusion. Secondary patency refers to repeat interventions aimed at restoring bypass patency after occlusion. Primary sustained clinical improvement in IC was defined as an upward shift of at least one category per Rutherford classification, accordingly to a level of claudication in patients with CLI. ResultsA total of 54 patients (54 limbs, 12 with CLI) were included. At 1 year, primary patency rates were 74% in IC and 27% in CLI (P = .001), primary assisted patency rates were 85% in IC and 68% in CLI (P = .05), and secondary patency rates were 89% in IC and 100% in CLI (P = .32). Accordingly, primary sustained clinical improvement rates were 64% in IC and 25% in CLI (P = .018). After adjustment for confounding factors, CLI (hazard ratio [HR], 7.8; 95% CI, 2.3–26.32; P = .001) and impaired patent runoff (ie, less than three crural runoff vessels; HR, 0.16; 95% CI, 0.03–0.96; P = .045) were independently associated with impaired primary patency. ConclusionsEndovascular revascularization is a reasonable treatment option to prevent impending bypass occlusion. Presence of CLI and impaired crural runoff are independent risk factors for lower patency rates.

Trends and outcomes after surgical lower limb revascularization in England

The aim was to analyse contemporary data on the number of surgical revascularization procedures performed each year in England, and their outcome. 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. 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 < 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 < 0·001) and 2·15 (1·88 to 2·45; P < 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). 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.

On-table endovascular intervention combined with infrainguinal bypass surgery—A district general hospital experience

To evaluate our practice of simultaneous on-table iliac angioplasty or stenting with infrainguinal bypass surgery in selected group of patients, we reviewed all patients who underwent on-table endovascular procedure combined with infrainguinal bypass surgery between 1995 and 1999. The procedures were performed in the absence of a radiologist. During the study period, 52 patients (mean age 64) underwent a combined procedure for disabling claudication, rest pain or ulceration. All patients were found to have multisegment disease on initial arteriogram with 65% having good distal run off. Patients underwent an endovascular procedure (63% on-table iliac angioplasty and 37% on-table iliac stenting) combined with femoro-popliteal bypass (52%), femoro-femoral crossover graft (36%), femoral endarterectomy (10%) and femoro-distal bypass (2%). Two thirds of patients had improvement in symptoms and ankle brachial pressure index during the early follow-up period (6 weeks). At the time of performing the audit, 7 patients (13%) have required further operations for limb salvage, and 3 patients (6%) underwent amputation. Patients with multilevel vascular disease may require multiple admissions for iliac stenting or angioplasty followed by distal vascular reconstruction. Vascular surgeons performing a combined procedure under one general anaesthetic can reduce the number of hospital admissions and interventions.

The deep veins in arterial reconstructive surgery for limb salvage in patients with multiple occlusions of the femoral and tibioperoneal vessels

Below-knee femoropopliteal and femorodistal bypass with nonautologous material shows poor patency rates, especially in multiple occlusions of the tibioperoneal vessels. Twenty-four patients underwent arterial reconstruction for limb salvage using the deep leg veins because the great saphenous vein was not available owing to previous operations. A follow-up period of forty-two months revealed an average bypass patency rate of 75%. During the control period all patients were prospectively investigated concerning changes in the venous system. The authors found only little changes in the venous system and no significant signs of venous insufficiency. The deep leg veins seem to be a valuable addition to arterial reconstructive surgery for limb salvage.

Diabetic Foot Amputations in Greece: Where Do We Go From Here?

The diabetic foot represents one of the major complications of diabetes, posing a tremendous impact on morbidity and mortality. Overall, 1 out of 4 patients with diabetes runs the risk of developing a foot lesion throughout his or her life. Worldwide, the prevalence of the diabetic foot in population-based studies ranges between 1.4% and 5.9%. In Greece, this prevalence has been reported at 4.75%. Diabetic foot ulcers represent the main cause of amputations. Hence, both established and emerging treatment modalities should be diligently applied in an attempt to reduce ulcers and amputations. In Greece, Doupis et al reported that the majority of diabetic foot patients had neuropathic (64.9%) rather than neuroischemic ulcers (35.1%). By contrast, Skoutas et al reported 52.1% frequency of neuroischemic, 17.9% frequency of ischemic, and 30% frequency of neuropathic ulceration. The latter authors have suggested that the frequency of the neuroischemic foot is rising in Greece. Of note, there is some evidence of significantly greater age and longer diabetes duration, male preponderance, as well as increased morbidity among neuroischemic in comparison with neuropathic foot patients and significantly higher frequency of smoking, hypertension, dyslipidemia, retinopathy, nephropathy, and coronary artery disease. Very little is known on the frequency of amputations in Greece. Karagianni reported a prevalence of 12.5/1000 patients in 1999, equivalent to 2.48/10 000 general population, mean 10-year incidence of amputations (1990-1999) was 3.7/1000 patients per year, equivalent to 0.59/10 000 general population per year. It was also reported that amputees suffered a mortality of 56%, which represented a 3-fold increase compared with the general population. Above knee amputations were 18%, below knee 18%, foot 29%, and toe 35%; importantly, 15% of amputations were bilateral. Furthermore, revascularization was only attempted in a minority of those patients, whereas the majority was treated by general surgeons of district hospitals. Repeat amputations are also reported to be more frequent. Papazafiropoulou et al observed that patients with diabetes required a second amputation and a contralateral amputation significantly more frequently than their nondiabetic peers. Skoutas et al found that ipsilateral re-amputation was required in 21.5% of patients during a mean follow-up of 18 months, whereas most re-amputations were performed within the first 6 months of the initial operation, age (hazard ratio 1.06 by increase of 1 year) and heel lesions (hazard ratio 2.69) were significantly associated with ipsilateral re-amputations based on multiple regression analysis of the data. Paradoxically, an initial choice of distal amputation in an attempt to minimize tissue loss increased the risk of ipsilateral re-amputation, especially in older subjects (≥70 years). Revascularization procedures, which may be either bypass surgery or percutaneous transluminal angioplasty, appear not to be used enough, although data are sparse. In 1999, underuse of femorodistal bypass surgery and similar revascularization procedures in Greece was reported. Since then, considerable progress seems to have been made. There are now 14 vascular departments accredited for training and about 200 vascular surgeons in the country. Substantial progress has also been accomplished in interventional radiology facilities, resulting in increased number of angioplasties. However, actual data of this progress are not yet available. Of further significance, revascularization is possible in large cities, but remains little available in small hospitals, leading to substantial geographical variation. Infection of chronic foot ulcers represents a major problem, especially in the presence of ischemia. Methicillin-resistant Stapylococcus aureus (MRSA) is a notorious microorganism, whose prevalence is very high in patients with infected foot ulcers. It is also alarming that MRSA infection or colonization was not associated with known risk factors, reflecting its increased prevalence in the community. When conservative medical measures fail to heal, surgery offering either wound incision and drainage, or amputation should follow. However, there is a lack of unanimity concerning the optimal timing and aggressiveness for such intervention. Against this background, the improvement in the study of the diabetic foot in Greece that has taken place since 2005 is of some reassurance. It was in this, the year of the diabetic foot, that specialists established the Greek Association for the Study of the Diabetic Foot and the Study Group of Neuropathy–Diabetic Foot of the Greek Diabetes Association. Thanks to these societies, more than 10 scientific meetings on the diabetic foot, targeting both local and nationwide

Femoro-Distal Bypass with Varicose Veins Covered by Prosthetic Mesh

The great saphenous vein (GSV) is the material of choice in distal bypass for critical limb ischemia (CLI). Varicosities have been reported as the cause of inadequacy of vein in up to 20% of patients. The hypothesis of this study is to consider the external mesh as a technique to use like conduit, in patients with varicose veins and in young patients with ecstatic veins, with results that at least overlap the traditional technique. We report our experience with bypass surgery using autologous varicose vein covered with prosthetic mesh. From May 2005 to July 2008, 249 infrapopliteal bypasses were performed to treat CLI. Twenty-one patients were selected from this group to receive bypass covered by polyester external mesh (ProVena; BBraun, Aesculap, Tuttlingen, Germany). Seventeen patients had varicose veins, four young patients had venous ectasia or previous bypass failure for dilatation. Graft patency was evaluated at 1, 3, 6, and 12 mo, and every 6 mo thereafter. All patients underwent epidural anesthesia with ropivacain 0.75%. The mean follow-up time was 32 mo. No dilatation or infection was found in this period. Two early bypass thromboses were recorded and treated immediately. Two lesions were treated at 3 and 8 mo with surgical substitution of the distal portion and PTA of focal intermediate stenosis, respectively. Primary patency at 24 mo was 57.1% (SE ± 3.9), assisted 81% (SE ± 3.2), and had an amputation-free survival rate of 85.7% (SE ± 2.8). In other bypass without mesh, primary patency was 63.8%, secondary 80.5%, and amputation-free survival rate 89.3% at 24 mo. Polyester external mesh is a valid method to perform bypass with autologous material, as ecstatic or varicose veins. Moreover, in young patients with long-term bypass patency expectancy, it prevents vein dilatation during arterialization process.

Transit-Time Volume Flow Measurements in Autogenous Femorodistal Bypass Surgery for Intraoperative Quality Control

The aim of this study was to assess intraoperative transit-time volume flow measurements (VFMs) as a tool for intraoperative evaluation of lower extremity arterial bypass grafts and to predict their patency. We analyzed 273 consecutive patients who had an infrainguinal bypass procedure using the great saphenous vein from 1998 until 2008; 103 had an intraoperative VFM. All intraoperative revisions were recorded and analyzed. Patency and revision rates were compared between those receiving and those not receiving intraoperative VFM. Cox regression was used for analysis of predictors of patency. Primary patency at 1 and 2 years was 75 and 67%, respectively, in patients receiving intraoperative VFM versus 72 and 69% in those without VFM (p = .79). In the VFM group, 12% had an immediate revision versus 6% without VFM (p = .06). In the VFM group, 4% underwent revision to salvage the bypass within the first postoperative 30 days versus 6% without VFM (p = .32). Patency was not associated with the use of VFM. Receiver operating characteristic curve was significant for occlusion at 30 days postoperatively but with a low predictive value (p = .019,area under the curve 0.648). VFM may be helpful in selecting bypasses requiring immediate revision to prevent postoperative occlusion. The use of VFM is not significantly associated with patency.

PTFE Bypass to Below-knee Arteries: Distal Vein Collar or Not? A Prospective Randomised Multicentre Study

Background Patency and limb salvage after synthetic bypass to the arteries below-knee are inferior to that which can be achieved with autologous vein. Use of a vein collar at the distal anastomosis has been suggested to improve patency and limb salvage, a problem that is analysed in this randomised clinical study. Methods Patients with critical limb ischaemia undergoing polytetrafluoroethylene (PTFE) bypass to below-knee arteries were randomly either assigned a vein collar or not in two groups – bypass to the popliteal artery below-knee (femoro-popliteal below-knee (FemPopBK)) and more distal bypass (femoro-distal bypass (FemDist)). Follow-up was scheduled until amputation, death or at most 5 years, whichever event occurred first. Results In the FemPopBK and in the FemDist groups, 115/202 and 72/150 were randomised to have a vein collar, respectively. Information was available for 345 of 352 randomised patients (98%). At 3 years, primary patency was 26% (95% confidence interval (CI) 18–38) with a vein collar and 43 (33–58) without a vein collar for femoro-popliteal bypass and 20 (11–38), and 17 (9–33) for femoro-distal bypass, respectively. The corresponding figures for limb salvage were 64 (54–75) and 61 (50–74) for femoro-popliteal bypass, and 59 (46–76) and 44 (32–61) for femoro-distal bypass with and without a vein collar, respectively. Log-rank-test for the whole Kaplan–Meier life table curve showed no statistically significant differences with or without vein collar primary patency: p = 0.0853, p = 0.228; secondary patency: p = 0.317, p = 0.280; limb salvage: p = 0.757, p = 0.187 for FemPopBK and FemDist, respectively. The use of a vein collar did not influence patency or limb salvage. Conclusion This study failed to show any benefit for vein collar with PTFE bypass to a below-knee artery.

Are femorodistal bypass grafts for acute limb ischemia worthwhile?

Background: It has been shown that autogenous veins are associated with the best limb salvage rates for femorodistal bypass surgery. However, in emergency settings, when an autogenous vein is unavailable, use of synthetic graft material or amputation is a critical decision to make. Objective: To assess the appropriateness of femorodistal bypass grafts for acute limb ischemia in emergency settings. Methods: Patients who underwent emergent bypass and elective femorodistal bypass surgery between 1996 and 2006 were reviewed retrospectively in a single center. Results: There were 147 patients of which 84 had elective and 63 had emergent bypass. The graft patency rates for elective admissions were 44 and 25% vs. 25 and 23% for admissions for acute femorodistal graft surgery at 2 and 4 years, respectively (p &lt; 0.004). Admissions for acute ischemia who were treated with prosthetic grafts had a primary patency of 24 vs. 27% for vein grafts at 2 years and 24 vs. 23% at 4 years (p = 0.33). In the acute femorodistal grafts group, primary patency at 2 years for vein and prosthetic grafts was 27 and 24% as compared to 42 and 32% for electives. These values for cumulative limb salvage rates for elective bypasses were 73 and 63% as compared to 52% at both time points in the acute femorodistal graft group (p &lt; 0.004). In emergency settings, the limb salvage rate for acute femorodistal bypass with prosthetic grafts was 38%, and for vein grafts it was 62% at both time points (p = 0.08). Conclusion: The long term limb salvage rate of 38% suggests that emergent femorodistal revascularization is worthwhile.

Surgical reconstructions in peripheral arterial occlusive disease

The prognosis of patients suffering from peripheral arterial occlusive disease (PAD) is directly correlated with the severity of the disease. In critically ischemic legs, after one year only 50% will be alive with a preserved leg. The other 50% will die or undergo an amputation during this time. Reconstructive surgery is highly effective in PAD caused by extensive arterial lesions. Depending on the localization of the occlusion, operative procedures range from local desobliteration to profundoplasty and from aortofemoral to femorodistal bypass procedures. Especially in critical ischemia, time is of the essence for limb salvage. Evidence-based data for diagnosis and operative treatment are described in detail. Only the consequent use of these critical techniques can improve the prognosis of these patients.

Cephalic Vein Graft Aneurysm – A Rare Presentation

We report a case of a non-anastomotic true aneurysm in an arterialized cephalic vein. This presented as a deep venous thrombosis due to local compression, 11 years after the cephalic vein had been used to revise a previous femoro-distal bypass. He had 3 further aneurysms, aortic and peripheral. The cephalic vein aneurysm was successfully repaired using a remnant of saphenous vein from the lower leg. This unique presentation suggests the importance of long-term surveillance in infra-inguinal bypass surgery in patients with systemic aneurysmal disease.

Hypoplastic posterior tibial artery and the enlarged peroneal artery supplying the posterior crural region: a rare variation

Arterial variations of distal parts of lower extremities are well-documented and can be demonstrated with the help of Doppler ultrasound or by arteriography. However, absence or variation of posterior tibial artery is considered a rare finding. We present a case of hypoplastic posterior tibial artery that terminated by supplying soleus muscle. The variant arterial supply to the sole was provided by the enlarged peroneal artery that continued as the lateral plantar artery. The awareness of these variations is important to vascular surgeons while performing arterial reconstructions in femorodistal bypass graft procedures, and also to orthopedists during surgical clubfoot release.

Nitric oxide synthase in critically ischaemic muscle and alterations in isoform expression during revascularization surgery

Dysfunction of the nitric oxide pathway is implicated in peripheral arterial disease. Nitric oxide synthase (NOS) isoforms and NOS activity were studied in muscle from patients with critical leg ischaemia (CLI). Alterations in NOS during revascularization surgery were also assessed. Muscle biopsies were taken from patients with CLI undergoing amputation and also from patients undergoing femorodistal bypass at the start of surgery, after arterial clamping and following reperfusion. The presence of NOS within muscle sections was confirmed using reduced nicotinamide adenine dinucleotide phosphate diaphorase histochemistry. NOS isoform distribution was studied by immunohistochemistry. NOS mRNA and protein levels were measured using real-time reverse transcriptase-polymerase chain reaction and western blotting. NOS activity was assessed with the citrulline assay. All three NOS isoforms were found in muscle, associated with muscle fibres and microvessels. NOS I and III protein expression was increased in CLI (P = 0.041). During revascularization, further ischaemia and reperfusion led to a rise in NOS III protein levels (P = 0.008). NOS activity was unchanged. Alterations in NOS I and III occurred in muscle from patients with CLI and further changes occurred during bypass surgery.