Duplex scan surveillance of infra-inguinal bypass grafts: the case for selectivity.

A consecutive series of 270 non-reversed infra-inguinal saphenous vein bypass grafts performed by the same surgeon between January 1986 and January 1991 was reviewed. The series included 250 in situ and 20 translocated non-reversed grafts. The aims were to calculate the number of duplex scans that would have been required for surveillance, to determine the value of a non-selective prolonged scanning regimen and to identify subgroups requiring more (or less) intensive surveillance. Indications were for critical ischaemia in 194 patients, popliteal aneurysms in seven patients and incapacitating claudication in 69 patients. Patients were reviewed at 1 month and then at approximate 6 month intervals for symptoms and with resting and post-exercise ankle pressures. Primary patency of grafts placed to a popliteal distal anastomosis for critical ischaemia was 85% (s.e.m. 9.1%) at 3 years while secondary patency was 94% (s.e.m. 8.1%) at 4 years. Primary patency of grafts placed to a tibial artery or isolated popliteal segment was 68% (s.e.m. 8.4%) at 2 years while secondary patency was 76% (s.e.m. 9.9%) at 2.5 years. The difference in secondary patency between popliteal and tibial grafts was highly significant (P = 0.003). Tibial grafts required significantly more secondary early intervention than popliteal grafts. If recommended protocols for serial duplex scan (DS) surveillance had been followed, a minimum of 960 scans would have been required. If the tibial bypass group only had been monitored, 702 of these scans would have been avoided with a maximum loss of one popliteal graft and no limbs.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of clinical follow-up and duplex surveillance of infrainguinal vein bypasses

The evidence in support of surveillance has been principally based on the favourable primary-assisted patency of stenosed grafts following revision (60–80% at 5 years) compared with the poor secondary patency of revised occluded grafts (20–40% at 5 years). Both the capital cost and workload generated by surveillance are considerable. More information is needed on the benefits of surveillance compared with clinical follow-up. A retrospective comparison of 50 vein grafts (44 reversed, six in situ) undergoing colour-coded duplex surveillance and 50 vein grafts (46 reversed, four in situ) under clinical follow-up, with duplex scans obtained only when clinically indicated, has been performed. Four (8%) stenoses of ≥50% were identified in the surveillance group. One 50% proximal anastomotic stenosis failed to progress on sequential scans. Three stenoses were treated (one mid graft, two popliteal) by vein patch angioplasty (two cases) and transluminal angioplasty (one case). Both groups were followed-up for 12 months. Secondary patency at 12 months (88% surveillance; 80% clinical follow-up) was not significantly different (P = 0.3). Similarly, limb salvage at 12 months (94% surveillance; 88% controls) was not significantly different (P = 0.4). A large randomized prospective study comparing duplex surveillance and clinical follow-up is warranted. Copyright © 1996 The International Society for Cardiovascular Surgery.     

Results of infrainguinal revascularization with reversed vein conduits: a modern control series

To determine the outcome of infrainguinal reversed vein bypasses in the modern era, we reviewed the results of 120 consecutive reversed vein grafts performed from March, 1986 to March, 1990. Forty-nine bypasses were to tibial, peroneal, or pedal arteries, 46 grafts to the below-knee popliteal artery, and 25 grafts to the above-knee popliteal artery. Limb salvage was the indication for revascularization in 70% of patients. All grafts were followed with serial, duplex scan, peak-systolic graft flow velocity measurements every three months for one year and every six months thereafter. The primary life table patency rate at 36 months was 67.6% for the entire series; the secondary patency rate was 92.5%. The secondary patency rate reflects the impact of graft revisions resulting from the detection of failing grafts by duplex scanning. Patency rates of reversed vein grafts to the tibial arteries at 36 months (73.8% primary and 89.8% secondary) were equivalent to those performed to the popliteal artery. Our current patency rates with reversed vein grafts are comparable or superior to those reported for in-situ vein conduits and suggest that operative technique and meticulous follow-up are more important with respect to long-term graft durability than whether the vein is used in the in-situ or reversed configuration.Presented at the Fifteenth Annual Meeting of the Peripheral Vascular Surgery Society, June 2, 1990, Los Angeles, California.The opinions expressed herein are those of the authors and do not necessarily represent those of the United States Air Force or the Department of Defense.     

The value of duplex surveillance after open and endovascular popliteal aneurysm repair

OBJECTIVE: The objective of this study was to determine the clinical value of vascular laboratory surveillance after open or endovascular repair of popliteal aneurysm by analysis of the frequency and nature of secondary interventions performed. METHODS: Over an 8-year period, 55 popliteal artery aneurysms were repaired in 46 men (mean age, 72 years) by aneurysm ligation and bypass grafting (vein, 37; prosthetic, 7), endoaneurysmorrhaphy and interposition grafting (prosthetic, 3; vein, 1), or endograft exclusion (n = 7). Indications for intervention included aneurysm thrombosis with critical limb ischemia (n = 8), symptomatic (n = 10) or asymptomatic (n = 37), >1.75 cm popliteal aneurysm with mural thrombus. Catheter-directed thrombolysis was used in three limbs to restore aneurysm and tibial artery patency before open repair. Duplex ultrasound surveillance was performed after repair to identify residual and acquired lesions. Life-table analysis was used to estimate repair site intervention-free (primary) and assisted-primary patency. RESULTS: During a mean 20-month follow-up interval, 20 secondary procedures were performed in 18 (31%) limbs to repair duplex-detected graft stenosis (n = 10), repair site thrombosis (n = 5), vein graft aneurysm (n = 3), graft entrapment (n = 1), or type 1 endoleak (n = 1). Primary patency was 76% and 68% at 1 and 3 years, and was uninfluenced by tibial artery runoff status or type of bypass conduit. Open (n = 12) or endovascular (n = 8) secondary procedures were performed on 15 (12 vein, 3 prosthetic) bypass grafts, 2 endografts, and 1 interposition graft. Mean time to repair graft stenosis (11 months) was shorter than to repair of vein graft aneurysm (37 months). Assisted-primary patency was 93% and 88% at 1 and 3 years; redo bypass grafting was required and successful in five limbs. Limb salvage was 100%. CONCLUSIONS: One third of popliteal artery aneurysms repaired by open or endovascular procedures required a secondary intervention within 2 years of repair. Repair-site surveillance using duplex ultrasound was able to identify lesions that threaten patency, which resulted in excellent assisted patency and limb preservation rates when corrected.     

Dacron femoral-popliteal bypass grafts in good-risk claudicant patients

PURPOSE: To evaluate prosthetic femoral-popliteal (FP) grafts as bypass conduits in favorable patients with refractory calf claudication. SETTING: University-affiliated urban teaching hospital. METHODS: Cohort study of patency of 6-mm Dacron FP grafts used to treat patients with medically refractory calf claudication meeting the following criteria: nonsmoker; above-knee popliteal artery as an appropriate target vessel; > or =2-vessel tibial outflow; and postoperative anticoagulation and antiplatelet therapy. End points included primary and secondary FP graft patency, need for and outcome of subsequent intervention, limb amputation, and survival. RESULTS: From January 1998 through March 2001, 92 patients underwent 100 Dacron bypass grafts for medically refractory claudication. All underwent serial postoperative graft surveillance using duplex ultrasound. Using the Society for Vascular Surgery/International Society of Cardiovascular Surgery criteria life-table, primary patency was 84%, assisted primary patency was 88%, and secondary patency was 90% at 5 years. Two patients (2%) died during a mean follow-up period of 49 months (range 30 to 68). No limbs required amputation. Among 9 limbs in which Dacron FP bypass failed, 8 underwent subsequent successful autogenous bypass to the popliteal artery. CONCLUSION: In highly selected subjects with favorable features known to increase the likelihood of prosthetic graft patency, prosthetic FP grafts function well. Such patients undergo a simpler, more straightforward procedure than when autogenous FP bypass is performed. Subsequent success of autogenous FP repeat bypass suggests that previous prosthetic FP bypass does not threaten lower-extremity arterial outflow.     

Durability of the in situ saphenous vein arterial bypass: a comparison of primary and secondary patency

The use of the saphenous vein in situ is associated with unique problems that decrease primary graft patency (patency uninterrupted by revision). During the past 5 years, we have performed 192 in situ saphenous vein bypasses in 182 patients, including 61 to the popliteal artery, 128 to infrapopliteal arteries, and three to isolated popliteal artery segments. The operative indications were critical limb ischemia in 178 cases (93%), popliteal aneurysm in eight cases (4%), and disabling claudication in six cases (3%). A progressive decline in primary patency occurred after operation. The primary patency rate at 36 months was only 48% for femoropopliteal bypasses and was 58% for femorotibial bypasses. In contrast, the secondary patency rate (patency maintained by thrombectomy, thrombolysis, or revision) at 36 months was 89% and 80% for femoropopliteal and femorotibial bypasses, respectively. The improved secondary patency was due to postoperative surveillance of graft hemodynamics and the success of graft revision. Problems unique to the in situ technique (incomplete valve incision, residual arteriovenous fistula, graft torsion and entrapment) accounted for 58% of early (less than 30 days) graft revisions and 52% of late revisions. The use of Doppler spectral analysis at operation and duplex scanning after operation can locate unsuspected technical errors and identify grafts with low flow at increased risk for failure. The primary patency of the in situ bypass mandates objective assessment of valve incision sites at operation and a protocol of postoperative surveillance to identify grafts that require revision. Early surgical intervention of hemodynamically abnormal but patent in situ bypasses is rewarded by excellent secondary patency.     

Arm Vein as a Last Autogenous Option for Infrainguinal Bypass Surgery: It is Worth the Effort

OBJECTIVES: Considerable evidence exists for the use of arm vein conduit in lower limb bypass surgery. The use of arm vein in preference to synthetic conduit as a last autogenous option was assessed for patency and limb salvage outcomes. MATERIALS AND METHODS: A prospective database was interrogated and checked against TQEH operating theatre database to detect all infrainguinal arm vein bypasses performed between 1997 and 2005. Patency, limb salvage and survival data for 37 arm vein bypasses was calculated using the Kaplan-Meier survival estimate method. RESULTS: There were no perioperative deaths. 30 day patency rates were 89% primary, 95% secondary and 95% limb salvage. 12 month patency rates were 56% primary, 79% secondary and 91% limb salvage. 5 year patency rates were 37% primary, 76% secondary and 91% limb salvage. There was no significant patency advantage for primary vs. "redo" grafts (p=0.54), single vessel vs. spliced conduits (p=0.33) or popliteal vs tibial outflow (p=0.80). Patient survival rate was 92% and 65% at 1 and 5 years respectively. CONCLUSION: Lower limb bypasses using arm vein can be performed with favourable patency and limb salvage compared to synthetic conduits. However, secondary interventions are frequently required to maintain patency. We recommend a vigilant surveillance program for early identification of patency threatening disease.     

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

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

Early results for below-knee bypasses using Distaflo

In patients who require lower extremity revascularization, prosthetic graft is a reasonable alternative in the absence of a suitable autologous vein conduit. However, prosthetic bypass grafts have limited patency, especially for infrageniculate reconstruction. Polytetrafluoroethylene grafts were geometrically modified at the distal end to increase their patency. The authors reviewed their experience with the Distaflo graft in patients who required lower extremity below-knee popliteal and tibial bypasses when no suitable autologous vein conduit was available. Chart review was conducted of the 57 patients who underwent 60 lower extremity bypasses over a 3-year period between June 2003 and April 2006. Twenty-four revascularizations were constructed to the tibial outflow sites, whereas the remaining grafts were placed to the below-knee (28) and above-knee (8) popliteal artery, respectively. Study endpoints were primary, assisted primary, secondary patency, and limb salvage at the time of follow-up. Distaflo bypass was performed at the infrageniculate level in 86.7% of cases (28 below-knee popliteal, 24 tibial). Mean follow-up time was 12 months (range, 0.5-37.5 months). At 1 year, primary, assisted primary, and secondary patencies and limb salvage rates for below-knee popliteal bypasses were 83.5%, 89.5%, 94.7%, and 94.4%, respectively. Primary, assisted primary, and secondary patencies and limb salvage rates for tibial bypasses were 44.4%, 44.4%, 63.2%, and 74.9%, respectively. Distaflo precuffed graft is a good alternative conduit for below-knee popliteal and tibial lower extremity reconstructions in the absence of an autologous vein and appears to have promising early patency and limb salvage rates even when used for tibial bypasses.     

Effectiveness of surveillance of infrainguinal grafts.

OBJECTIVE: To audit the surveillance programme of infrainguinal vein graft in a tertiary vascular unit, and find out how effective it was in preventing occlusion of grafts. DESIGN: Retrospective study. SETTING: Teaching hospital, Scotland. SUBJECTS: 59 consecutive patients who had 61 vein grafts between 1996 and 1998 for critical limb ischaemia. INTERVENTIONS: Grafts scanned at 3-monthly intervals for at least a year, and clinical review. MAIN OUTCOME MEASURES: Survival with an intact limb and patency of the graft. RESULTS: 52 of the 59 patients (90%) were alive at the time of follow up, and 55 of the 61 involved limbs (90%) were intact. Median follow up was 660 days (range 180-1995). 23 stenoses were detected by the surveillance programme. 17 grafts were revised, all of which were patent at follow up, and 8 other grafts occluded requiring 6 major amputations. One-year cumulative primary, primary-assisted, and secondary patency, and limb salvage rates were 63%, 88%, 88%, and 90% respectively. CONCLUSIONS: Surveillance of infrainguinal grafts by duplex scanning is effective and has resulted in high rates of limb salvage and secondary patency in patients who presented with critical ischaemia.     

Monitoring functional patency of in situ saphenous vein bypasses: the impact of a surveillance protocol and elective revision

Implementation of a protocol that monitored in situ saphenous vein bypass hemodynamics for low-flow states provided insight into the pathophysiologic characteristics and time course of graft failure. From 1981 to 1988, 250 in situ bypasses to popliteal (n = 83) or tibial (n = 167) arteries were performed in 231 patients. Indications for operation included critical limb ischemia in 232 cases (93%), popliteal aneurysm in 11 cases (4%), and disabling claudication in seven cases (3%). Arterial pressure measurements, continuous-wave Doppler spectral analysis, and duplex ultrasonography were used to assess patency, detect hemodynamic changes indicative of graft stenosis, and localize anatomic hemodynamic changes indicative of graft stenosis. Seventy grafts with correctable anatomic lesions (retained venous valves, graft stenosis, arteriovenous fistula, native vessel atherosclerosis) that decreased graft blood flow or ankle arterial pressure or both were identified. Correction of vein conduit or anastomotic lesions comprised 73 (77%) of the 95 revisions performed. Vein-patch angioplasty of a stenosis was the most common secondary operation performed. Graft revision was highest in the perioperative period (10% at 30 days), decreased to 7% per 6-month interval until 18 months, and was 3% per year thereafter. The primary patency rate of grafts not identified to have a correctable lesion was 86% at 4 years, a level similar to the secondary patency of 81% for grafts requiring one or multiple revisions. The surveillance protocol identified grafts with correctable lesions before thrombosis thereby permitting elective revision of patent grafts. Hemodynamic studies confirmed that a frequent mechanism of late failure of grafts was the development of a low-flow state produced by lesions not amenable to revision.     

A RETROSPECTIVE ANALYSIS OF INFRA-INGUINAL ARTERIAL RECONSTRUCTION: THREE YEAR PATENCY RATES

Primary infra-inguinal arterial reconstructions were reviewed for primary patency and outcome of thrombosis in 144 patients. Distal anastomoses in these patients were to the popliteal artery and were above the knee in 63, below the knee in 53 and at the tibial level in 28. The treatment used was: polytetrafluoroethylene (PTFE) in 33 cases, PTFE with an interposition vein cuff in 29 cases, autogenous saphenous vein (ASV) in situ in 47 cases, and reversed technique in 26 cases. Life table analysis showed a 59% overall primary patency at 3 years. Patency rates of above knee anastomoses (65%) and below knee (61%) were statistically different from the tibial anastomoses (42%. P = 0.005). In both above and below knee popliteal anastomoses there was a statistically significant difference in the patency of ASV and the PTFE/vein cuff technique (P= 0.0006) but there was no difference between ASV and FTFE. There was no difference in patency rates for the various types of grafts with tibial anastomoses. Data were analysed at 3 years, taking into account the variables of smoking, diabetes or indications for surgery respectively and no difference was found in patency. The number and calibre of the run-off vessels did not influence patency significantly, hence anastomosis to any good quality vessel regardless of run-off is recommended. The poor results with the interposition vein cuff technique are unexplained but this study suggests that the technique should he reserved for anastomoses below the popliteal artery.     

Contribution of routine intraoperative completion arteriography to early infrainguinal bypass patency.

To determine the clinical utility of routine intraoperative completion arteriography, we prospectively evaluated 214 consecutive infrainguinal bypass grafts (209 reversed-vein and 5 polytetrafluoroethylene grafts) performed from July 1987 to August 1991. Visual inspection, pulse palpation, and continuous-wave Doppler examination were performed in all cases. At least 1 completion arteriogram was obtained in 213 cases (99%). The bypasses were to the popliteal artery in 130 cases and to the tibial or pedal arteries in 84 cases. Graft patency was confirmed at 30 days in all patients by ankle-brachial index determinations (greater than 0.2 increase) and duplex scan-derived peak-systolic flow velocities (greater than 45 cm/s). Significant technical problems requiring revision were identified in 18 grafts (8%), including 6% of popliteal grafts and 12% of tibial/pedal grafts. Only three of these problems were suspected by pulse palpation or continuous-wave Doppler examination. The intraoperative angiographic findings leading to revision included distal anastomotic stenoses (n = 6), distal arterial disease requiring sequential bypass (n = 4), mid-graft valvular or branch ligature stenoses (n = 4), distal arterial thrombosis (n = 2), and graft kink or twist (n = 2). Thirty-day primary patency was 99% (129 of 130) for femoropopliteal grafts and 93% (78 of 84) for femorodistal grafts. Secondary patency was 100% (130 of 130) and 96% (81 of 84), respectively. Primary patency was 89% (16 of 18) for those grafts that required intraoperative revision based on arteriographic findings. We conclude that routine completion arteriography is an excellent method of ensuring the intraoperative technical adequacy of infrainguinal bypass. The test is easy to perform, reproducible, and should be considered the "gold standard" for intraoperative bypass assessment. Prior to adopting angioscopy or duplex scanning for intraoperative surveillance, randomized, controlled validation studies against angiography should be performed.     

The relative importance of graft surveillance and warfarin therapy in infrainguinal prosthetic bypass failure

BACKGROUND: We sought to describe modes of failure and associated limb loss after infrainguinal polytetrafluoroethylene bypass grafting in patients lacking a saphenous venous conduit and to define specific clinical or hemodynamic factors prognostic for bypass failure. METHODS: We identified 121 patients (mean age, 67 years; 90 men and 31 women) with determinable outcomes (minimum follow-up, 2 months; mean, 17 months) after 130 prosthetic infrainguinal bypasses between 1997 and 2005. Ischemic presentation was rest pain in 52%, tissue loss in 34%, and disabling claudication and/or popliteal aneurysm in 14%, with 24% of patients requiring a redo bypass. Distal targets were the above-knee (n = 44), distal popliteal (n = 27), or tibial/pedal (n = 59) arteries. Sixty-six (77%) of the below-knee (BK) target (distal popliteal or tibial) bypasses had distal anastomotic adjuncts (vein cuff or patch). Duplex graft surveillance was performed at 1, 4, and 7 months after surgery and twice yearly thereafter, with recording of midgraft velocities and imaging encompassing inflow and outflow vessels. Arteriography and open/endovascular intervention was performed for stenoses identified by duplex scanning (peak systolic velocity >300 cm/s; velocity ratio >3.5). An attempt was made to salvage occluded grafts by using catheter-directed thrombolysis or open techniques. Eighty-six patients (74% of BK bypasses) were placed on chronic warfarin therapy with a target international normalized ratio range between 2 and 3. Prognostic factors were identified by using univariate statistics and multivariate logistic regression analysis. RESULTS: Three-year primary, assisted, and secondary patency rates were 39%, 43%, and 59%, respectively, for all bypasses, with no difference noted between above-knee and BK grafts (P = .5). At 3 years, freedom from limb loss was 75%, and patient survival was only 70%, with no adverse effect on survival imparted by amputation. Sixty-nine total adverse events occurred as a result of thrombotic occlusion (n = 51), duplex scan-detected stenosis (n = 13), or graft infection (n = 5). Forty-nine percent of all initial graft occlusions eventually led to amputation. Twenty-three grafts (27% of 86 patients) in patients maintained on chronic warfarin were subtherapeutic at the time of occlusion. Use of a distal anastomotic adjunct with BK bypasses reduced graft thrombosis (35% with vs 60% without) but did not impart a significant patency advantage (P = .07). Multivariate analysis revealed low graft flow (midgraft velocity < or =45 cm/s; odds ratio [OR], 6.1; 95% confidence interval [CI], 1.9-19.2), use of warfarin (OR, 8.4; 95% CI, 2.1-34.5), and therapeutic warfarin (OR, 24.6; 95% CI, 5.7-106) to be independently predictive for bypass patency. Graft patency was maintained in 89% of grafts remaining therapeutic on warfarin compared with only 55% of subtherapeutic or nonanticoagulated grafts (P < .001). Low-flow grafts (n = 61) occluded more frequently than higher-flow grafts (46% vs 13%; P < .001). Therapeutic warfarin augmented the patency of low-flow (P < .001) but not high-flow (P = .15) grafts. CONCLUSIONS: Low graft flow was a more common mode of prosthetic bypass failure than development of duplex scan-detected stenotic lesions during follow-up. Early duplex scanning may be more important for characterizing midgraft velocity and related thrombotic potential and selecting patients for chronic anticoagulation. Maintenance of therapeutic warfarin is paramount in optimizing prosthetic bypass patency and limb preservation.     

The "all-autogenous" tissue policy for infrainguinal reconstruction questioned

In 33% of patients referred for infrainguinal reconstruction for limb-threatening ischemia (mean preoperative ankle-arm index [AAI] = 0.26), no suitable autogenous reconstruction was possible. In 40% of cases, intraoperative pre-bypass contrast arteriography was necessary to identify a graftable tibial or pedal artery. The results of polytetrafluoroethylene (PTFE) and autogenous bypasses were compared after 1 to 3 years. After 1 year, patency was 85% and 67% for autogenous and PTFE bypasses, respectively. Limb salvage was 90% for autogenous bypass and 70% for PTFE bypass. Cumulative patency rates at 3 years were 80% for autogenous and 57% for PTFE grafts. Graft surveillance with duplex scanning and AAI was valuable in detecting failing grafts. For both types of reconstruction, secondary procedures were required to maintain patency. We attribute the excellent results with PTFE in part to long-term aspirin and warfarin therapy. In cases of combined superficial femoral and severe infra-popliteal occlusive disease, PTFE bypass is an excellent alternative when no autogenous conduit is available.     

Acute occlusion of popliteal and/or tibial arteries: the value of percutaneous treatment.

OBJECTIVES: to describe early and mid-term results with a percutaneous therapeutic protocol including thromboaspiration, thrombolysis, and correction of the underlying lesion by PTA. METHODS: thirty-three consecutive selected patients with recent (<1 month) reversible acute ischaemia associated with popliteal and/or tibial occlusion were studied. The primary endpoints were technical success (defined as residual mural thrombus less than 20% of the lumen and the presence of at least one tibial artery on angiogram), patient survival and limb salvage at 1 and 12 months. Secondary endpoints included complications, primary, assisted primary and secondary patency determined by duplex scan at 1, 6 and 12 months. RESULTS: technical success was achieved in 27 patients (82%). Twenty patients were treated by thrombo- aspiration+/-thrombolysis only, and seven required additional PTA (26%). In six patients (18%), percutaneous techniques failed, and embolectomy was performed in two, bypass in one and major amputations in three (9%). For the entire series, the survival rate was 100% at 1 month and 94% at 1 year. The limb salvage rate was 91% at 1 month and 1 year. The cumulative primary patency, assisted primary patency and secondary patency rates were 81%, 81% and 86% respectively at 1 month and 66%, 72% and 77%, respectively, at 12 months. Early complications occurred in 10 patients (30%): five groin haematomas (15%), four compartment syndromes (12%) and one haemoglobinuria (3%). CONCLUSION: percutaneous techniques offer excellent early and mid-term results in selected patients presenting with acute ischaemia with popliteal and/or tibial arteries occlusion.     

Natural history of infrainguinal vein graft stenosis relative to bypass grafting technique

Purpose: To determine whether the incidence of vein graft stenosis is related to bypass grafting technique and thus modification of postoperative surveillance protocols may be required.Methods: From 1991 to 1996, 338 infrainguinal vein bypasses constructed using in situ (n = 131), reversed (n = 120), nonreversed translocated (n = 48), or spliced/upper extremity vein (n = 39) grafting techniques were evaluated by intraoperative duplex scanning to optimize bypass construction and serially thereafter to detect developing vein graft stenoses. Bypass procedures were performed in 322 patients for critical limb ischemia (83%), claudication (13%), or popliteal aneurysm (4%). Using life-table analysis, graft patency and revision/failure rates were compared relative to grafting technique, need for operative revision, and intraoperative duplex scan results.Results: Three-year primary and secondary graft patency rates were higher (p < 0.001) for in situ bypass grafts (85%/97%) compared with reversed (57%/83%), nonreversed translocated (62%/78%), or alternative (51%/76%) vein bypass grafts. During a mean follow-up interval of 19 months, the incidence of graft revision was higher for reversed saphenous (23%) and alternative (28%) vein bypass grafts compared with in situ (10%) or nonreversed (16%) saphenous vein bypass grafts. Despite a normal intraoperative graft duplex scan, the revision/failure rate of reversed vein grafts was 2.5 times greater than in situ/nonreversed translocated vein conduits (primary patency rate at 3 years, 60% vs 87%, p = 0.009). Bypass grafts modified at operation on the basis of duplex scanning were two times more likely to require postoperative revision than grafts with normal intraoperative scans.Conclusions: The incidence of postoperative graft stenosis and need for revision varies with bypass grafting technique. Reversed vein bypasses and grafts modified at operation may be more prone than in situ vein bypass grafts to develop stenosis and thus require intensive surveillance. Infrainguinal vein graft failure and the need for revision may be reduced by the adoption of bypass grafting techniques that include valve lysis and intraoperative duplex scan assessment. (J Vasc Surg 1997;25:211-25.)     

Factors affecting the outcome of 463 femorotibial reconstructions

Between 1973 and 1986, 463 infrapopliteal bypasses were performed on 408 limbs in 383 patients at Royal Prince Alfred Hospital. There were 265 males and 118 females. Their mean age was 69 years, 30% were diabetic, 71% smoked and 38% were hypertensive. The indication for surgery was threatened limb loss in 350 limbs and short distance claudication in 58 limbs. The peri-operative mortality rate was 5%. Cumulative graft patency was 58% (s.e.m. = 2.7) at 5 years. The limb salvage rate was 66% (s.e.m. = 2.5) at 5 years. Cumulative patency rate for autogenous grafts (n = 332) was 63% (s.e.m. = 3.2) at 5 years compared with the cumulative patency rate for synthetic grafts (n = 131) of only 38% (s.e.m. = 5) at 5 years (P less than 0.05). There was no significant difference between the cumulative patency of autogenous grafts originating from the common femoral artery (n = 195) and those from the superficial femoral artery (n = 111). Cumulative patency of autogenous grafts did not significantly differ with the site of distal anastomosis; posterior tibial (n = 79), anterior tibial (n = 98), peroneal artery (n = 138) with 5-year cumulative patency rates of 65% (s.e.m. = 6.4), 65% (s.e.m. = 6.1) and 70% (s.e.m. = 4.6) respectively (P greater than 0.05). Autogenous graft material is the most important determinant of a durable result from femorotibial bypass. Proximal and distal anastomotic sites should be chosen to allow maximal utilization of available autogenous vein.     

Lower extremity revascularization with in situ saphenous vein for critical ischemia

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