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Background: It has been suggested that ultrasonography could replace diagnostic arteriography in the assessment of patients who present with leg ischaemia. This study investigated a group of consecutive patients who had femorodistal bypass and who were assessed before operation with colour-coded duplex and dependent Doppler insonation alone., Methods: Thirty-seven consecutive patients with critical lower limb ischaemia underwent surgical exploration with a view to femorodistal bypass. Results of preoperative colour-coded duplex and dependent Doppler insonation were compared with intraoperative arteriograms and surgical findings., Results: There was very good agreement between colour-coded duplex imaging and dependent Doppler insonation with intraoperative angiography and surgical findings in the prediction of the optimal run-off vessel (kappa = 1.0) and the site of the distal anastomosis (kappa = 0.85; 95 per cent confidence interval 0.71-1.0). There was also very good agreement between dependent Doppler insonation and intraoperative arteriography (kappa = 1.0) in predicting pedal arch patency and the predominant feeding vessel., Conclusion: Assessment of leg arteries before femorodistal bypass can be performed accurately with non-invasive colour-coded duplex imaging and dependent Doppler insonation alone, thus obviating the need for preoperative arteriography.

Background: The aim of the study was to investigate whether infrainguinal vein graft surveillance can be stopped at 1 year without prejudicing graft or leg survival., Methods: Data were collected prospectively on 351 infrainguinal vein bypass grafts (326 patients) that had been entered into a vein graft surveillance programme between 1988 and 1997., Results: Some 104 grafts (30 per cent) developed significant new vein graft stenoses, 95 (91 per cent) of which occurred within 12 months. After 1 year, the risk of developing a significant graft stenosis was 3 per cent per year. Sixty-nine grafted limbs (20 per cent) developed new arterial inflow or run-off stenoses that required intervention, but only 37 (54 per cent) occurred within the first year, after which the risk was 9 per cent per year. The overall risk of developing a new vein graft or arterial stenosis after 1 year was 10 per cent per year., Conclusion: The incidence of vein graft stenosis decreases significantly 1 year after operation but there is still at risk of developing potentially graft-threatening arterial stenoses. Legs that have undergone infrainguinal vein bypass grafting should continue to be monitored in a surveillance programme for life.

Background: To assess the impact upon the provision of a vascular service of the workload associated with maintaining infrainguinal bypass graft patency., Design: A computerised prospective audit., Materials and Methods: Between January 1990 and December 1995, all patients with infrainguinal bypass grafts were entered into a prospective computerised audit to monitor interventions for the maintenance of graft patency. Excluded from the study were interventions during the first 30 postoperative days and procedures not directly related to the graft. A graft surveillance programme was in operation throughout., Results: During the study period a total of 131 patients with 144 grafts were admitted on 330 occasions and required 401 separate interventional procedures. There were 227 procedures in 72 femorodistal grafts, 116 in 38 below-knee femoropopliteal grafts and 58 interventions in the group of 34 above-knee femoropopliteal grafts. Radiological interventions accounted for almost 70% of this workload., Conclusion: The workload associated with the maintenance of infrainguinal bypass grafts increased considerably during the study period, and seems likely to increase further. Such interventions should therefore be considered when planning for vascular service provision.

Objectives: To determine the peak velocity ratio (PVR) threshold at which to intervene and correct duplex detected vein graft stenoses., Design: Prospective study., Materials: Infrainguinal vein grafts in patients attending the vascular studies for routine postoperative surveillance., Methods: Colour duplex detected stenotic vein graft lesions with a peak velocity ratio (PVR) between 2.0 and 2.9 were identified and monitored by serial duplex scans performed monthly for 3 months and then at 3-monthly intervals thereafter. At the end of the study period, the outcome of these lesions were analysed., Results: Thirty-eight lesions were identified from 32 grafts. Of these lesions, sixteen (42%) resolved, 11 (29%) remained stable and 11 (29%) progressed to a PVR of > or = 3.0 and underwent angioplasty. There were no occlusions in any of the grafts during the period of study., Conclusions: Colour duplex detected vein graft stenoses with a PVR of less than 3.0 can be treated expectantly if grafts with stenoses with a PVR 2.0-2.9 are scanned every month for at least 3 months after detection.

Objectives: To elucidate the incidence of significant vein graft stenosis in patients who have undergone bilateral infrainguinal vein grafts., Materials: Between 1987 and 1996, 22 patients were identified from our vascular studies database as having undergone bilateral infrainguinal vein bypass grafting., Methods: Data was obtained from the vascular studies database and by case note review. All patients had been part of a vein graft surveillance programme., Results: Of the 22 patients with bilateral vein grafts, eight were excluded from further analysis because one or more of their grafts failed within 30 postoperative days. In the remaining 14 patients (28 vein grafts) there were 15 primary vein graft stenoses. Six patients (43%) had bilateral vein graft stenoses, which is significantly higher (p = 0.0008) than the predicted value of 9%, for developing bilateral vein graft stenoses. For those patients who developed a vein graft stenosis in their first grafted limb (9/14), 67% (6/14) subsequently developed a vein graft stenosis in their second grafted limb., Conclusion: Patients who develop vein graft stenosis in one limb are at a greater risk of developing a contralateral vein graft stenosis if that limb is grafted. This may well be due to individual vein morphology or unidentified systemic factors that play a role in the aetiology of vein graft stenosis.

Purpose: Endovascular aneurysm repair has been advocated as a "minimally invasive" alternative to conventional aneurysm surgery. However, because of manipulation within the aneurysm sac, endovascular techniques may result in massive microembolization., Methods: In this study lower limb microemboli were quantified in 29 patients undergoing conventional (11 straight and 7 bifurcated grafts) and endovascular aneurysm repair (8 aortoiliac, 1 straight, and 2 bifurcated grafts) by insonation of the superficial femoral artery with a 2 MHz Doppler probe. Emboli were detected as high-intensity, short-duration signals on the background Doppler trace. Differentiation of gaseous emboli from particulate emboli was achieved by calculation of the sample volume length (emboli velocity x duration = sample volume length) for each embolus (N = 4927). Previous experiments had determined that a sample volume length < 1.4 cm represented particulate embolization., Results: The number of gaseous, particulate, and total emboli were significantly greater in the endovascular group compared with the conventional group (p < 0.05)., Conclusions: These data demonstrate that peripheral microembolization is significantly higher during endovascular aneurysm repair than during conventional surgery. Methods to reduce embolization must be developed before endovascular aortic surgery is widely adopted.

The purpose of this study was to review the outcome of adopting colour-coded duplex ultrasonography as the primary imaging modality in patients with symptomatic lower-limb arterial disease. Over a 12-month period 467 consecutive lower-limb duplex scans were performed of which 437 (94 per cent) were technically adequate. Of the 467 limbs, 184 (39 per cent) were managed conservatively, 230 (49 per cent) were referred for percutaneous transluminal angioplasty (PTA), 41 (9 per cent) underwent reconstructive surgery and 12 (3 per cent) required diagnostic arteriography. In patients referred for PTA there were only 22 (10 per cent) unexpected findings; there was agreement about superficial femoral artery occlusion length in 95 (89 per cent) of 107 limbs and about the presence or absence of a superficial femoral artery stump in 91 (85 per cent) of 107 cases. In patients referred for surgery there were no unexpected findings. Colour-coded duplex imaging can safely replace diagnostic arteriography in up to 97 per cent of lower limbs with arterial disease.

Aim: To review outcome of 40 consecutive infrapopliteal percutaneous transluminal angioplasty (PTA) procedures performed over a 65 month period., Chief Outcome Measures: The indication for PTA was intermittent claudication in 20 (50%) cases and rest pain, ulceration or gangrene in the remainder., Results: There was one technical failure; the remaining 39 limbs were all clinically improved by 24 h and this improvement was maintained at 3 months in 36 (90%). There were no deaths nor limb loss related to PTA and 2 embolic complications were successfully treated percutaneously. The primary and secondary symptomatic patencies at 24 months were 59 and 79% respectively. The actuarial limb salvage rate at 1 year for the 20 limbs presenting with critical ischaemia was 77%, and 10 of the 14 procedures performed for ulceration or gangrene resulted in healing with only minor surgical intervention., Conclusions: With modern endovascular techniques, infrapopliteal PTA is a safe, worthwhile and durable procedure.

Objective: To evaluate the ability of preoperative intraarterial digital subtraction angiography (IADSA) to predict the feasibility of infragenicular reconstruction and site of the distal anastomosis., Design: Prospective study., Setting: University Hospital, Materials: 45 patients with 50 ischaemic limbs, considered potential candidates for infragenicular reconstruction., Chief Outcome Measures: Pre-reconstruction intraoperative angiography (IOA) was used as the gold standard. Analysis of angiograms was performed blindly and independently by a single observer. In patients who ultimately underwent primary amputation, exploration and attempted angiography of the crural and ankle vessels was performed to verify the IADSA findings., Main Results: There was 87% accuracy (kappa = 0.66) between IADSA and IOA in differentiating between a normal, stenosed and occluded tibial artery and there was 86% accuracy (kappa = 0.67) in determining the adequacy of run-off into the pedal arch. IADSA had a positive predictive value of 100% to determine the feasibility of reconstruction but a negative predictive value of only 73%. After excluding those patients tha IADSA deemed non-reconstructable, IADSA had a positive predictive value of 97% to determine the correct artery and 92% to determine the correct segment of artery for distal anastomosis., Conclusions: IADSA could not determine when reconstruction was not possible, but in those deemed reconstructable by IADSA, the surgeon can confidently expose the appropriate artery at the appropriate level knowing the pedal run-off status in 86% of patients. IADSA should not be used to exclude reconstruction (i.e. pre-reconstruction IOA is still required in these patients) but for the remainder, IADSA can be used to plan surgical strategy without recourse to IOA.

The merits of an aggressive policy of distal reconstruction have been questioned by some observers. To determine the factors affecting graft patency and mortality, we analysed 78 consecutive infragenicular femorodistal vein grafts performed in 72 patients with critical limb ischaemia. The primary, primary assisted and secondary graft patency rates at 36 months were 29, 57 and 64%, respectively. The limb salvage and patient survival rates at 36 months were 67 and 74%, respectively. Univariate analysis (log-rank test) was performed to identify factors affecting graft patency, limb salvage and mortality at 1 month (perioperative) and 1 year. Independent variables of age, sex, diabetes, presentation, level of anastomosis and vein technique (reversed or in situ) did not affect graft patency. The ankle systolic pressure did not predict graft patency but was an independent variable affecting mortality (p = 0.047), as did diabetes (p = 0.019). These results show that excellent limb salvage can be successfully achieved in severely ischaemic patients by adopting an aggressive approach to femorodistal bypass, and that age, gender and poor medical condition are not contraindications to femorodistal bypass. The difference between the primary and primary assisted patency rates in this series is dramatic and reflects the impact of a vein graft surveillance programme in preventing graft occlusion.

The impact of interventional radiology on the cumulative patency rate of 112 consecutive infrainguinal vein grafts was reviewed. The primary, primary assisted and secondary cumulative patency rates at 42 months were 40, 65 and 69 per cent respectively. The difference between primary and primary assisted patency rates (40 versus 65 per cent, P = 0.001) resulted from the early detection and treatment of stenoses in 30 grafts by percutaneous transluminal angioplasty (PTA). Interventional radiology also improved the cumulative graft patency rate through PTA of one inflow and five outflow arteries, thrombolysis of two graft occlusions, embolization of two persistent arteriovenous fistulas and salvage of one graft on the first day after operation by percutaneous aspiration of distal graft thrombus. Interventional radiology has a crucial role to play in the maintenance of infrainguinal vein graft patency; provided that graft stenoses are detected early in their development by aggressive graft surveillance, PTA is a highly effective treatment.

Thirty-eight patients presenting with severe limb ischaemia and considered unfit for major aortic reconstruction underwent axillofemoral bypass as a limb salvage procedure. Four patients (11 per cent) died, including two who had presented with bilateral ischaemia secondary to acute aortic occlusion. The operative mortality rate for patients presenting with rest pain or ulceration/gangrene was 6 per cent. Cumulative 5-year survival and limb salvage were 44 per cent and 86 per cent respectively. Graft occlusion was the principal cause of worsening symptoms during follow-up (5-year primary patency of 68 per cent) and accounted for all major amputations of the operated limb. Axillounifemoral grafts had a significantly worse 5-year patency (50 per cent) than axillobifemoral grafts (80 per cent, P less than 0.05) and three of five patients who developed worsening symptoms in the non-operated limb died or required a major limb amputation as a consequence. Axillofemoral bypass is a valuable alternative to major aortic reconstruction in elderly patients and allows a greater proportion to be offered reconstruction than would otherwise be possible.

Over a 10-year period, aortofemoral grafting was employed in the revascularization of 484 limbs in 245 patients with peripheral limb ischaemia. Six patients (2.4%) died in the postoperative period, the most common cause of death being myocardial infarction. Forty-three patients (18%) developed significant non-fatal complications within 30 days of operation, half of whom required further surgery as a consequence. Thirty-seven patients suffered late graft-related complications of which graft thrombosis was the most common. Immediate graft patency was 98.4%, cumulative patency was 95% and 87% at 1 and 5 years respectively. False aneurysm formation was encountered in 3.3% of patients, deep graft sepsis in 1.6% and the phenomenon of 'non-healing' of grafts in 1.2%. Cumulative survival following elective surgery was 97% and 84% at 1 and 5 years respectively, and 89% and 72% for those undergoing limb salvage procedures.

Over a 10-year period, 241 patients with non-aneurysmal aortoiliac disease underwent aortofemoral bypass to 476 limbs. Four patients (1.7 per cent) occluded their grafts within 30 days of surgery, while 25 (10.4 per cent) suffered late graft occlusion. Postoperative occlusions were associated with significant morbidity and only one patient avoided major limb amputation or death. Overall, 46 episodes of graft thrombosis involving 51 graft limbs were encountered, the most common underlying cause being pre-existing or progressive multilevel distal occlusive disease. The overall cumulative graft patency rates were 95 and 87 per cent at 1 and 5 years respectively. Cumulative 5-year patency was significantly higher in patients presenting with claudication (91 per cent) than in patients presenting with rest pain (77 per cent) or ulceration and/or gangrene (71 per cent). Patients with evidence of multilevel distal occlusive disease at the time of aortic surgery had a significantly higher incidence of occlusion compared with those in whom there was no significant distal disease. In 35 episodes of occlusion (76 per cent), surgery was undertaken to restore limb blood flow, being successful in all but one case, with the most commonly performed procedure being graft limb thrombectomy. Seven of 28 patients (25 per cent) ultimately required major limb amputation and three patients died as a direct consequence of graft thrombosis.