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

The Role of Pre and Postprocedural Color Duplex Ultrasound for the Treatment of Lower Limb Ischemia by Subintimal Angioplasty

Introduction

Subintimal angioplasty (SIA) is the endovascular recanalization of vessels in the subintimal plane and most often is used to treat long-segment occlusions involving the femoropopliteal segment. This study demonstrates the value of pre- and postprocedural color duplex ultrasound (CDU) imaging.

Methods

Forty-three subintimal angioplasty procedures were performed to treat lower-extremity arterial occlusions. CDU was used as the definitive imaging modality in all cases. There were 26 women and 17 men, with a mean age of 76 years. Sixteen patients had anklebrachial index < 0.45. Most patients had significant medical comorbidities, placing them at high risk for arterial bypass procedures.

Results

In all patients, the extent of the occlusion was accurately diagnosed with CDU before intervention. SIA was technically successful in 42 of 43 patients (98%). The postprocedure CDU follow-up (1–2 months) demonstrated 10 patients had reoccluded (24%). Our primary patency rate was 42% at 30 months.

Conclusion

SIA can be an effective method of treatment in aged, high-risk patients with lower-extremity ischemia and threatened limb loss. CDU accurately locates the site of and measures the length of arterial occlusions in such patients, allowing the interventionalist to plan the site of arterial puncture and to prognosticate the likely success. CDU obviates the need for diagnostic angiography and remains the modality of choice for surveillance after SIA intervention.

Meta-analysis of femoropopliteal bypass grafts for lower extremity arterial insufficiency

BACKGROUND

In femoropopliteal bypass surgery, the use of saphenous vein grafts is preferable, but synthetic grafts are widely used above the knee. The objective of this meta-analysis was to assess the long-term patency of femoropopliteal bypass grafts classified as above-knee polytetrafluoroethylene, above-knee saphenous vein, or below-knee saphenous vein.

METHODS

Studies published from 1986 through 2004 were identified from electronic databases and reference lists; 73 articles contributed 1 or more series that used survival analysis, assessed femoropopliteal bypasses in one of the foregoing configurations, reported a 1-year graft patency rate, and included at least 30 bypasses. The series with a predominance of claudicant patients were included in meta-analysis C, and the series in which critical ischemia predominated were included in meta-analysis CI. Pooled survival curves of graft patency were constructed.

RESULTS

In meta-analysis C, the pooled primary graft patency was 57.4% for above-knee polytetrafluoroethylene, 77.2% for above-knee vein, and 64.8% for below-knee vein at 5 years; there was a significant difference between above-knee grafts at 3, 4, and 5 years (P < .05). The corresponding pooled secondary graft patency was 73.2%, 80.1%, and 79.7%, respectively (P > .05). In meta-analysis CI, the pooled primary graft patency was 48.3% for above-knee polytetrafluoroethylene, 69.4% for above-knee vein, and 68.9% for below-knee vein at 5 years; there was a significant difference between above-knee grafts until 4 years (P < .05). The corresponding pooled secondary graft patency was 54.0%, 71.9%, and 77.8%, respectively, with a significant difference between above-knee grafts at 2, 3, and 4 years (P < .05).

CONCLUSIONS

The great saphenous vein performs better than polytetrafluoroethylene in femoropopliteal bypass grafting and should be used whenever possible.

Postoperative lower extremity bypass surveillance: beyond ankle arm blood pressures

Surveillance is essential to the postoperative follow-up of lower extremity bypass grafts. Early, intermediate, and late thrombosis place the patient's limb at risk, so detection of problems before the graft fails is critical. Because contrast angiography is not routinely performed for surveillance, most vascular surgeons rely on history, physical examination, and noninvasive vascular studies (NVS) to assess perfusion to the lower extremity after bypass grafting. These NVS include ankle/brachial waveforms, blood pressures, and indexes before and after exercise. The purpose of this study is to report our findings with duplex color-flow ultrasonography (DCU) to examine lower extremity bypass grafts. According to our protocol, we monitor lower extremity grafts with ankle/brachial Doppler pressures, analogue waveforms, and lower extremity exercise when possible. These NVS are performed by nurses in the vascular laboratory before the patient is discharged from the hospital, at least twice during the first year, and then annually. DCU is also performed at least two times during the first year and then annually. If the study results are abnormal or if the patient has symptoms, testing is usually repeated. When abnormalities persist contrast angiography may be warranted. We have detected anatomic and hemodynamic changes in lower extremity bypasses by use of our protocol. By adding DCU to ankle/brachial blood pressures, we have identified aneurysmal dilation, diffuse atherosclerosis, focal narrowing, arteriovenous fistulas caused by unligated venous branches, retained venous valves, and disease progression proximal or distal to the graft.(ABSTRACT TRUNCATED AT 250 WORDS)