The long-term outcome of infrainguinal vein graft surveillance

Infrainguinal revascularisation in the era of vein-graft surveillance--do clinical factors influence long-term outcome?

OBJECTIVES

To investigate the variables affecting the long-term outcome of infrainguinal vein bypass grafts that have undergone postoperative surveillance.

DESIGN

A retrospective analysis.

PATIENTS AND METHODS

Details of 299 consecutive infrainguinal vein grafts performed in 275 patients from a single university hospital were collected and analysed. All grafts underwent postoperative duplex surveillance. Factors affecting patency, limb salvage and survival rates were examined. These factors were gender, diabetes, hypertension, aspirin, warfarin, ischaemic heart disease, run-off, graft type, early thrombectomy, level of anastomoses and indication for surgery.

RESULTS

The 6-year primary, primary assisted and secondary patency rates were 23, 47, and 57%, respectively. Six-year limb salvage and patient survival were 68 and 45%, respectively. Primary patency was adversely influenced by the use of composite vein grafts. Early thrombectomy was the only factor that significantly influenced secondary patency. Limb salvage was worse in diabetic limbs, limbs with poor run-off and in grafts that required early thrombectomy. Postoperative survival was better in males, claudicants and in patients who took aspirin.

CONCLUSIONS

Although co-morbid factors did not influence graft patency rates, diabetes did adversely effect limb salvage. This study, like others before it, confirms that aspirin significantly reduces long-term mortality in patients undergoing infrainguinal revascularisation.

Colour-coded duplex imaging and dependent Doppler ultrasonography in the assessment of cruropedal vessels

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.

Lower limb surveillance following autologous vein bypass should be life long

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.

The progression and correction of duplex detected velocity shifts in angiographically normal vein grafts

OBJECTIVES

To review the sensitivity of duplex scanning and angiography at detecting vein graft stenoses in patients on a graft surveillance programme.

DESIGN

Prospective, open, non-randomised study.

PATIENTS AND METHODS

Since February 1993, 143 patients with 148 grafts (70% in situ, 30% reversed) have attended postoperative infrainguinal vein graft surveillance for a minimum of 6 weeks. Fifty-seven graft stenoses in 57 grafts were identified by duplex scanning as a localised high velocity jet. Angiography was performed in all except 12 patients.

RESULTS

Angiography confirmed a duplex abnormality in all but 10 patients. Of these, five patients remain stable and asymptomatic with a persisting duplex abnormality. The remaining five patients, although asymptomatic, exhibited disease progression on duplex and surgical intervention confirmed significant stenoses, which were successfully treated.

CONCLUSION

The results suggest that duplex scanning is a reliable imaging modality for detecting vein graft stenoses. Selection for surgical correction can be made, in some circumstances on the basis of clinical and ultrasound criteria alone.

Economising vein-graft surveillance programs

OBJECTIVES

To investigate the effectiveness of two alternative vein-graft surveillance strategies. In the first strategy surveillance was restricted to patients with a possible higher risk of significant stenosis development, i.e., those with a moderate stenosis identified early after the operation. In the second strategy the effects of reducing the number of duplex tests per patient was examined.

PATIENTS AND METHODS

In a prospective study in three vascular surgical departments 300 patients (300 femoropopliteal or distal grafts) underwent duplex surveillance during the first year after the operation. The duplex-derived PSV-ratio was considered to represent the degree of stenosis. Arteriographic confirmation of suspected stenoses was routinely obtained, and patients without a suspected graft stenosis underwent a consented arteriogram during the first postoperative year. The decision to perform a graft revision was taken on the basis of an arteriographic stenosis of at least 70% diameter reduction. In the first strategy graft categories were defined on the basis of the first postoperative duplex examination: grafts with a PSV-ratio < 1.5, grafts with a PSV-ratio < 1.5-2.0, grafts with a PSV-ratio of 2.0-2.5, grafts with PSV-ratios 2.5-3.0, and grafts with PSV-ratios > 3.0. The primary patency rate at 12 months was compared for these categories. In the second alternative strategy the number of examinations and the percentage of event causing de novo stenoses were analysed per surveillance interval.

RESULTS

The presence of moderate abnormalities at the initial duplex scan did not identify patients with a high risk of an event, as initial PSV-ratios of 1.5-2.0 and 2.0-2.5 (early mild-moderate lesions) had comparable 12-month primary patencies to patients with a PSV-ratio < 1.5 (completely normal grafts): (63%, 73%, and 71%, respectively). The interval incidence of event causing de novo stenoses was 8% of the total number of duplex tests performed at 3 months, and 8% at 6 months after the operation. In patients who had no previous intervention for stenosis and had a normal bypass during the first 6 months postoperatively, a sharp drop in this incidence was seen at 9 and 12 months, with event causing de novo stenoses observed in only 2% and 1% of all duplex tests.

CONCLUSIONS

All patients should be included in a surveillance program, as the presence of a normal vein graft at the first duplex examination does not rule out the subsequent development of graft stenosis. The duration of the surveillance period may be restricted to the first 6 months after operation in patients who have a normal bypass during that time period, as only few stenoses will be missed by this policy.

Early results of percutaneous transluminal angioplasty (PTA) of failing below-knee bypass grafts

OBJECTIVES

An audit of treating femoro-crural bypass stenosis in the first instance by PTA.

DESIGN

Prospective clinical pilot study in consecutive patients.

MATERIALS

Prior to vascular bypass grafting all patients had critical ischaemia. Sixty-four PTA procedures in 50 grafts in 49 patients were carried out. Thirteen were in situ saphenous grafts, 16 were combined venous segments, 18 were combined PTFE and vein and three were PTFE only.

METHODS

Conventional cross-over or antegrade PTA, eventually combined with local thrombolytic therapy.

RESULTS

The nine-month assisted patency using PTA was 72%, following surgical repair in five cases after failed PTA the secondary patency was 86%. The amputation free survival rate was 88%. In 11 cases thrombosis was treated successfully with local thrombolysis. In two cases the balloon ruptured the native artery wall below the distal anastomosis with pseudoaneurysm formation. Six limbs were amputated during follow-up. The frequency of stenosis in combined grafts was significantly higher than in in situ vein grafts.

CONCLUSION

Our results are comparable with surgery. About 600 hospital beds/days were saved. This shortened the time from the diagnosis of stenosis to therapy and shortened the waiting list for vascular surgery.

The predictive value of angiographic results for the outcome of percutaneous transluminal angioplasty in stenosed femoral bypass grafts

PURPOSE

To assess the predictive value of immediate angiographic results after percutaneous transluminal angioplasty (PTA) for stenoses in femoral bypass grafts using duplex ultrasound (DUS) criteria.

METHODS

A 1-year follow-up with DUS was performed in 38 patients with 50 stenoses in 41 grafts, treated with PTA for a graft stenosis. The indication for PTA according to DUS criteria was a severe stenosis in 43 lesions, and a moderate stenosis in 7 lesions. In the moderate stenosis group 3 patients showed claudication and 1 patient had a nonhealing ulcer. For the purposes of statistical evaluation, primary patency was considered present if the graft was not occluded. The graft was considered to have failed when it was found to be occluded on DUS, or when secondary interventions (surgery, repeat PTA) were performed.

RESULTS

After 1 year the cumulative primary patency rate was 44% [95% confidence interval (CI) 27.8-59.8]. Stenoses with initially good angiographic results after PTA (< 30% residual stenosis) were 2.9 times more likely to be patent at 1 year than stenoses with initially poor or moderate angiographic results (hazard ratio 2.9, 95% CI 1.3-6.4, p = 0.007).

CONCLUSION

A poor or moderate angiographic result immediately following PTA was prognostic for poor long-term results and may indicate a requirement for earlier surgical intervention.