Duplex ultrasound scanning of peripheral arterial disease of the lower limb.

OBJECTIVES: To assess the reliability and applicability of duplex ultrasound scanning (DUS) of lower limb arteries, compared with digital subtraction angiography (DSA), in patients with peripheral arterial disease (PAD). DESIGN: A prospective, blinded, comparative study. MATERIALS AND METHODS: A total of 169 patients were examined by DUS and DSA. Intermittent claudication (IC) was present in 42 (25%) patients and critical limb ischaemia (CLI) in 127 (75%) patients. To allow segment-to-segment comparison, the arterial tree was divided into 15 segments. In total, 2535 segments were examined using kappa (κ) statistics to test the agreement. RESULTS: The agreement between DUS and DSA was very good (κ>0.8) or good (0.8 ≥ κ>0.6) in most segments, but moderate (0.6 ≥ κ>0.4) in the tibio-peroneal trunk and the peroneal artery. Agreement between the two techniques was significantly better in the supragenicular (κ=0.75 (95% confidence interval (CI): 0.70-0.80)) than in the infragenicular segments (κ=0.63 (0.59-0.67)) (p<0.001). Similarly, the technical success rate was significantly higher in the supragenicular segments (DUS: 100%; DSA: 99%) than in the infragenicular segments (both 93%) (p<0.001). DUS was the best technique for imaging of the distal crural arteries (92% vs. 97%; p<0.001) and DSA was the best technique for imaging of the proximal crural arteries (95% vs. 91%; p<0.01). Neither the agreement nor the technical success rate was influenced by the severity of PAD, that is, IC versus CLI. CONCLUSION: The agreement between DUS and DSA was generally good, irrespective of the severity of ischaemia. DUS performed better in the supragenicular arteries than in the infragenicular arteries. However, DUS compared favourably with DSA in both tibial vessels, particularly in the distal part, which makes DUS a useful non-invasive alternative to DSA.

Minimum training requirement in ultrasound imaging of peripheral arterial disease.

OBJECTIVES: To demonstrate the minimum training requirement when performing ultrasound of peripheral arterial disease. DESIGN: Prospective and blinded comparative study. MATERIAL: 100 limbs in 100 consecutive patients suffering from peripheral arterial disease, 74% suffering critical limb ischemia, were enrolled during a 9 months period. METHODS: One physician with limited ultrasound experience performed all the ultrasound examinations of the arteries of the most symptomatic limb. Before enrolling any patients 15 duplex ultrasound examinations were performed supervised by an experienced vascular technologist. All patients had a digital subtraction arteriography performed by an experienced vascular radiologist, unaware of the ultrasound result. RESULTS: The number of insufficiently insonated segments (non-diagnostic segments) was significantly reduced during the study; from 9% among the initial 50 limbs to 2% among the last 50 limbs (P<0.0001). This improvement was evident only in the infragenicular segments, as the performance within the supragenicular segments was good from the beginning. There was no change in the agreement between ultrasound and arteriography from the initial 50 patients (overall Kappa=0.66, (95%-CI: 0.60-0.72); supragenicular Kappa=0.73 (95%-CI: 0.64-0.82); infragenicular Kappa=0.61 (95%-CI: 0.54-0.69)) to the last 50 patients (overall Kappa=0.66 (95%-CI: 0.60-0.72), supragenicular Kappa=0.67 (95%-CI: 0.57-0.76); infragenicular Kappa=0.66 (95%-CI: 0.58-0.73)). CONCLUSION: The minimum training requirement in ultrasound imaging of peripheral arterial disease appears to be less than 50 ultrasound examinations (probably only 15 examinations) for the supragenicular segments and 100 examinations for the infragenicular segments.

Ultrasound imaging of infrainguinal arterial disease has a high interobserver agreement.

OBJECTIVES: to evaluate and compare the operator dependency of duplex ultrasound and digital subtraction arteriography (DSA) in patients suffering from chronic lower limb ischaemia. DESIGN: prospective and blinded validation study. MATERIAL: twenty-six consecutive patients (13 male and 13 females) with severe claudication (n=6, 23%), rest pain (n=7, 27%) or tissue loss (n=13, 50%). METHODS: two physicians independently performed a duplex scan of the lower limb from groin to foot (15 segments). Segments were classified as insignificantly (<50% stenosis) or significantly (>50% stenosis or occlusion) diseased. DSA was performed within 24h of the duplex scanning and was independently reported by two radiologists in the same manner. Interobserver agreement was assessed for both diagnostic methods. After 10 months the arteriograms were reassessed and the intraobserver agreement calculated. RESULTS: for the limb as a whole the interobserver agreement was good and similar for both duplex and DSA, with kappa-values of 0.79 (95%-CI: 0.72-0.86) and 0.80 (0.74-0.87). In the femoral, crural and pedal segments the interobserver agreement was similar for both methods. The intraobserver agreement between the two DSA readings was 0.84 (0.79-0.90). CONCLUSION: ultrasound is comparable to arteriography when visualising arterial occlusive disease in patients with chronic lower limb ischaemia.

Screening for aortoiliac lesions by visual interpretation of the common femoral Doppler waveform.

OBJECTIVE: to study the accuracy of simple visual interpretation of the common femoral artery Doppler waveform for screening the aorto-iliac segment for significant occlusive disease. DESIGN: prospective and semi-blinded study. Material ninety-four consecutive and elective patients having arteriography due to chronic lower limb ischaemia, presenting symptoms of severe claudication (23%), ischaemic rest pain (34%) or ischaemic skin lesions (43%). METHODS: one day prior to conventional arteriography a Doppler waveform was obtained in the common femoral artery. Based on visual interpretation, the waveforms were immediately categorised as normal or abnormal. Comparison with single plane arteriography with respect to significant aorto-iliac occlusive disease was undertaken. RESULTS: visual Doppler waveform interpretation had a sensitivity of 98% (95% CI: 90-100%), a specificity of 81% (CI: 67-90%), a positive predictive value of 86% (CI: 75-93%) and a negative predictive value of 97% (CI: 86-100%) for prediction of significant aorto-iliac occlusive disease using conventional arteriography as the gold standard. The kappa value for the agreement between Doppler waveform interpretation and arteriography was 0.81 (0.68-0.93), representing very good agreement. CONCLUSION: a normal common femoral Doppler waveform can safely exclude significant upstream aorto-iliac lesions and is a useful timesaving screening tool in the busy vascular laboratory. The method is well tolerated, easy to perform and requires no additional equipment.

[Thrombolytic therapy in acute lower extremity ischemia]. / Trombolysebehandling ved akut underekstremitetsiskaemi.

During a period of four and a half years 37 lower extremities with acute ischaemia were treated with thrombolysis. Angiographically, 35 cases demonstrated no suitable arteries for distal reconstruction. In two cases vascular surgery was not performed because of cardiac incompensation. Two patients died within one month and limb salvage was 69%. During 22 months (3-48) of follow-up another six patients were amputated two to nine months later. The 18 salvaged lower extremities (49%) had an ankle-brachial pressure index of 0.63 (0.30-1.-09). Review of all angiograms revealed a demonstrable effect of thrombolytic therapy only in 13 (35%) cases. In conclusion, thrombolytic therapy should be considered in the case of acute lower extremity ischaemia unsuitable for reconstructive procedures. Even though the effect of thrombolytic therapy cannot be demonstrated on the angiogram, that should not necessarily deem the treatment to be a failure.

[Percutaneous transluminal angioplasty of iliac occlusions]. / Perkutan transluminal angioplastik af iliacaokklusioner.

Percutaneous transluminal angioplasty (PTA) has become an established treatment modality for iliac artery stenosis. PTA of iliac artery occlusions, however, remains a topic of controversy due to difficulties with mechanical recanalization, a lower patency rate and a higher complication rate than obtained after PTA of iliac artery stenosis. During a three year period, we performed 31 PTA's of iliac artery occlusions. The primary recanalization rate was 71% (22 occlusions). Stents were applied in 16 patients. The cumulated patency rates were 95% and 85% after one and six months respectively. There was one late reocclusion after two years. We found a tendency towards inferior patency in the longer occlusions (> or = 5cm). The complication rate was 10% due to three episodes of distal embolisation, all of which were successfully treated immediately with additional PTA and stenting. These results are in accordance with the results of international studies, and suggest that PTA is a useful alternative to surgical treatment of iliac artery occlusions, albeit long occlusions involving both the common and the external iliac artery should be excluded.