Duplex ultrasonography and pulse-generated run-off in selecting claudicants for femoropopliteal angioplasty

Classificação angiográfica na revascularização do membro inferior isquêmico: pode a angiografia definir a resistência do leito receptor do enxerto?

CONTEXTO: A arteriografia é muitas vezes utilizada como único método pré-operatório para a definição da conduta terapêutica na revascularização do membro isquêmico, seja ela realizada através de angioplastia transluminal, ou de cirurgia convencional. Ainda hoje, sua utilização é assunto de debate. OBJETIVO: Comparar um método de classificação arteriográfica simples com estudos hemodinâmicos pré e intraoperatórios do leito arterial isquêmico a ser revascularizado, com o objetivo de verificar seu poder para definir a resistência desse leito arterial. MÉTODOS: Foram analisadas 68 cirurgias de revascularização de membros inferiores isquêmicos realizadas no período de julho de 1999 a julho de 2004 no Setor de Cirurgia Vascular do Instituto Dante Pazzanese de Cardiologia. As características do leito arterial receptor do enxerto foram estudadas e comparadas através de método de classificação arteriográfica pré-operatória proposto pelos autores, análise hemodinâmica pré-operatória por eco-Doppler colorido e intraoperatória por medidas diretas de vazão, pressão e resistência. RESULTADOS: Foram observados índices de correlação de Spearman positivos (p < 0,05) entre o sistema de classificação arteriográfica pré-operatória proposto e as medidas hemodinâmicas ultrassonográficas pré-operatórias de volume de fluxo sanguíneo (p = 0,035) e as medidas diretas intraoperatórias de vazão (p = 0,006), pressão (p = 0,037) e resistência (p = 0,006). CONCLUSÃO: O método de classificação arteriográfica pré-operatória proposto pode definir a resistência do leito arterial a ser revascularizado e auxiliar na definição da conduta e do prognóstico da revascularização do membro inferior isquêmico.

Remote endarterectomy: first choice in surgical treatment of long segmental SFA occlusive disease?

OBJECTIVES

to report the long term results of remote superficial femoral artery endarterectomy (RSFAE) with the MollRing Cutter for the treatment of long segmental SFA occlusive disease.

DESIGN

retrospective open study.

PATIENTS AND METHODS

from March 1994 to August 2000 183 RSFAEs were performed in 164 selected patients (105 males, 120 procedures) with a median age of 63 years (43-84 years). Indications for operation were disabling intermittent claudication in 129 procedures (70%), rest pain in 20 procedures (11%), and limb salvage in 34 procedures (19%). Follow up consisted of clinical evaluation, ankle-brachial index measurements and duplex scanning.

RESULTS

the mean follow-up time was 29.3 months. The mean length of the endarterectomised SFAs was 31 cm (range, 17-45cm). The five year cumulative primary patency rate by means of life table analysis was 37.8+/-6.67% (SE). Percutaneous transluminal balloon angioplasty and surgical re-intervention were performed in twenty-nine and four patients respectively resulting in a primary assisted patency rate of 47.9+/-6.27%. Limb salvage was achieved in 30 of the 34 patients. Females had a statistically significant lower primary patency rate, i.e., 26 vs 45% (p -value=0.01).

CONCLUSIONS

the long term results of remote SFA endarterectomy show that it is a safe, effective and durable, minimally invasive procedure. It also leaves open all other options for conventional bypass procedures. The five-year primary patency rate is at least similar to prosthetic above-knee bypass surgery.

Duplex scanning allows selective use of arteriography in the management of patients with severe lower leg arterial disease

PURPOSE

Until April 1997 we routinely performed intra-arterial digital subtraction angiography (iaDSA) in all patients with severe lower leg ischemia requiring intervention. After a comparative study of duplex scanning (DS), pulsegenerated runoff, and iaDSA of the lower leg arteries, we postulated that management could be based on DS/pulse-generated runoff in 59% of patients. We prospectively evaluated the safety of such a noninvasive workup strategy.

METHODS

All consecutive patients referred with severe lower leg ischemia between April 1997 and September 1998 were eligible. Management was based on DS with iaDSA being performed only on indication. Complications within 30 days and 12- and 24-month patency, survival, and limb salvage rates were recorded and compared with historical controls.

RESULTS

A total of 125 limbs in 114 patients were evaluated (74% rest pain or tissue loss). In 97 (78%) of 125 limbs, management was based on DS. It comprised conservative treatment (n = 33, 0% after iaDSA), percutaneous transluminal angioplasty (n = 25, 16% iaDSA), femoropopliteal bypass graft (n = 29, 17% iaDSA), femorotibial bypass graft (n = 29, 62% iaDSA), and other surgical procedures (n = 8, 4% iaDSA). Overall, the mortality within 30 days was 4% (5/114), and 2-year survival was 83%. Two-year primary and secondary patency and limb salvage rates were 75%, 93%, and 93% after a femoropopliteal bypass operation, respectively. One-year primary and secondary patency and limb salvage rates were 35%, 73%, and 74%, respectively, after a femorocrural bypass operation. There were no differences in patient characteristics, indication for specific treatment, and immediate and intermediate term outcome between the study and reference population.

CONCLUSION

In a vascular unit with wide expertise in DS of the lower leg arteries, management of patients with severe lower leg ischemia can be based on DS in most patients without negative effects on clinical outcome within 30 days and at 2-years' follow-up.

Peripheral arterial disease: gadolinium-enhanced MR angiography versus color-guided duplex US--a meta-analysis

PURPOSE

To summarize and compare the published data on gadolinium-enhanced magnetic resonance (MR) angiography and color-guided duplex ultrasonography (US) for the work-up for peripheral arterial disease.

MATERIALS AND METHODS

Studies published between January 1984 and November 1998 were included if (a) gadolinium-enhanced MR angiography and/or color-guided duplex US were performed for evaluation of arterial stenoses and occlusions in the work-up for peripheral arterial disease of the lower extremities, (b) conventional angiography was the reference standard, and (c) absolute numbers of true-positive, false-negative, true-negative, and false-positive results were available or derivable.

RESULTS

With a random effects model, pooled sensitivity for MR angiography (97.5% [95% CI: 95.7%, 99.3%]) was higher than that for duplex US (87.6% [95% CI: 84.4%, 90.8%]). Pooled specificities were similar: 96.2% (95% CI: 94.4%, 97.9%) for MR angiography and 94.7% (95% CI: 93.2%, 96.2%) for duplex US. Summary receiver operating characteristic analysis demonstrated better discriminatory power for MR angiography than for duplex US. Regression coefficients for MR angiography versus US were 1.67 (95% CI: -0.23, 3.56) with adjustment for covariates, 2.11 (95% CI: 0.12, 4.09) without such adjustment, and 1.73 (95% CI: 0.44, 3.02) with a random effects model.

CONCLUSION

Gadolinium-enhanced MR angiography has better discriminatory power than does color-guided duplex US and is a highly sensitive and specific method, as compared with conventional angiography, for the work-up for peripheral arterial disease.

Can cruropedal colour duplex scanning and pulse generated run-off replace angiography in candidates for distal bypass surgery

PURPOSE

To compare the diagnostic accuracy of duplex scanning (DS) and pulse generated run-off (PGR) with ia-DSA for the assessment of cruropedal outflow and explore the reliability of clinical decision making based on a work-up with DS/PGR in candidates for peripheral bypass surgery.

METHODS

Popliteal, crural and pedal arteries were evaluated independently with DS and ia-DSA in 126 limbs of 120 consecutive patients for claudication (16%) or critical ischaemia (84%). Arterial segments were graded with DS and ia-DSA as normal, stenosed, or occluded and compared using weighted kappa (kappa) analysis. PGR was used to select the best crural artery for bypass. Proposed management based on DS/PGR and, if applicable, anastomosis site were compared to definitive treatment based on ia-DSA.

RESULTS

Overall agreement between DS and ia-DSA for popliteal and crural arteries was moderate (kappa 0.51, 95% CI 0.48-0.55) with good agreement within the popliteal (kappa 0.67) and anterior tibial (kappa 0.61) arteries. Agreement was moderate within the pedal arterieds (kappa 0.32, 95% CI 0.24-0.40). In 74/126 (59%) limbs proposed management with DS/PGR was identical to ia-DSA. In 23/29 (79%) femoropopliteal and 15/37 (41%) femorocrural bypasses DS/PGR agreed perfectly with ia-DSA with regard to acceptor artery and anastomosis site.

CONCLUSION

DS can accurately assess the popliteal and anterior tibial arteries. In a substantial number of patients with severe lower limb ischaemia decisions for conservative management, PTA and femoropopliteal bypass can be based on a DS/PGR work-up.

Investigation of peripheral arterial disease--the expanding role of echo-enhanced color flow doppler and duplex sonography

Contrast angiography is widely regarded as the gold standard investigation in peripheral artery disease (PAD). It produces images that are diagnostically valuable, but is limited by its inability to image the vessel walls or the dynamics of blood flow in the lumen. Color duplex sonography is increasingly used in PAD to replace or pre-empt angiography. It is a simple non-invasive technique that gives information about both structural and dynamic anomalies in the peripheral arteries, with an accuracy close to that of angiography. Certain situations are difficult to visualize using this technique. Arteries that are deep-lying, calcified, obscured by fat or bowel gas, or that contain low-velocity blood flow, will generate sub-optimal scans due to inadequate returning signal strength. This can be corrected by the use of microbubble echo-enhancing agents, which increase the strength of the returning signal, generating a clear image from which a diagnosis can be made. Results of multicenter studies of echo-enhanced color duplex sonography in PAD are reviewed and the impact of the technique on the diagnostic work-up of PAD is assessed.

Economic analyses of radiological procedures: a methodological evaluation of the medical literature

OBJECTIVE

Increasing pressure to curb health care costs has led to considerable interest in economic analyses, including both cost-effectiveness and cost-benefit analyses. Numerous economic analyses of radiological procedures have appeared in both the radiology and non-radiology literature. The objective of this study was to evaluate the methodological quality of economic analyses of radiological procedures published in the non-radiology medical literature during the years 1990 1995.

METHODS

Original investigations from the medical (non-radiological) literature that include economic analyses of radiological interventions were identified from a computerized literature search. Each economic analysis article was evaluated by two independent reviewers for adherence to ten methodological criteria. The criteria were derived from review of the medical and radiological economic analysis methodology literature and consisted of the following: (1) Comparative options stated; (2) perspective of analysis defined; (3) outcome measure identified; (4) cost data included; (5) source of cost data stated; (6) long term costs included; (7) discounting employed; (8) summary measure provided; (9) incremental computation method used; and (10) sensitivity analysis performed. The results were compared to a previous study that evaluated the radiological literature.

RESULTS

Of the 56 articles in the medical literature that included economic analyses of radiological procedures, only eight (14%) conformed to all ten methodological criteria. The cost data (98%) and comparative options (89%) criteria exhibited high compliance, while the perspective of analysis (25%) and discounting (32%) criteria had relatively low compliance. Agreement between the reviewers was excellent (kappa = 0.88).

CONCLUSIONS

Published economic analyses of radiology procedures usually do not meet accepted methodological standards.

Full-dose and half-dose Klean Prep produce clearer images with iliac duplex examination than picolax

OBJECTIVES

Iso-osmotic bowel preparation (Klean Prep) improves the accuracy of iliac duplex examination and reduces the time of each examination. Full-dose Klean Prep entails 4 l of fluid. We studied the effect of 2 l of Klean Prep (half-dose) and Picolax on image quality.

DESIGN

Prospective study comparing clarity of duplex examination after three different bowel preparation regimes with that after 12 h starvation.

MATERIALS AND METHODS

Thirty patients underwent iliac duplex examination after 12 h starvation. Scans were scored subjectively for grey scale and colour image quality, and Doppler signal-to-noise ratio. Patients were allocated blindly to: (a) full-dose Klean Prep, (b) half-dose Klean Prep, or (c) Picolax. After out-patient preparation, the scan was repeated and scored by the same observer, blinded to the preparation.

RESULTS

Both full- and half-dose Klean Prep produced significant improvements in image quality for all three modalities; Picolax produced minimal change. There was minimal advantage of full-dose over half-dose Klean Prep. Patients preferred half-dose Klean Prep to full-dose.

CONCLUSION

Klean Prep significantly improves the image obtained by iliac duplex examination; Picolax does not. Half-dose Klean Prep is an acceptable preparation to patients.

Colour flow duplex imaging of occlusive arterial disease of the lower limb

BACKGROUND

The development of duplex ultrasonography and colour flow imaging has greatly extended the scope of non-invasive assessment of lower limb arterial disease. This review questions whether recent advances might allow colour duplex imaging to displace arteriography as the primary imaging modality for native vessel occlusive disease.

METHODS

A literature review was carried out based predominantly on a Medline database search of English language publications from 1985 to 1996.

RESULTS

Increasing evidence indicates that colour duplex ultrasonography can accurately image the lower limb native arterial tree, and that colour duplex imaging can replace diagnostic arteriography in a large proportion of patients.

CONCLUSION

Arteriography should no longer be considered the gold standard of imaging of peripheral arterial occlusive disease. Future studies should concentrate on the efficacy of colour duplex sonography in guiding clinical decision making.

Colour-coded duplex imaging can safely replace diagnostic arteriography in patients with lower-limb arterial disease

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.

Can lower limb vascular reconstruction be based on colour Duplex imaging alone?

OBJECTIVES

To determine the safety and efficacy of Duplex scanning as the only imaging modality prior to lower limb vascular reconstruction.

DESIGN

Retrospective review.

SETTING

A single university vascular unit.

PATIENTS AND METHODS

Review of all lower limb vascular reconstructions over a 2 year period.

RESULTS

Eighty-five limbs underwent vascular reconstruction based on colour Duplex alone. A wide range of revascularising operations were performed, including 29 cases of infragenicular reconstruction. In the latter cases, the findings of Duplex scanning were confirmed by on table pre-reconstruction angiography in 28 cases and the graft occlusion rate in the first month was 14%. There were no postoperative complications that could be attributed to a failure of preoperative Duplex imaging.

CONCLUSION

Vascular reconstruction can be undertaken safely in patients with lower limb arterial disease on the basis of Duplex scanning alone.

Summary receiver operating characteristic curves as a technique for meta-analysis of the diagnostic performance of duplex ultrasonography in peripheral arterial disease

RATIONALE AND OBJECTIVES

We summarized and compared the diagnostic performance of duplex and color-guided duplex ultrasonography in the evaluation of peripheral arterial disease. We present our research as an example of the use of summary receiver operating characteristic (ROC) curves in a meta-analysis of diagnostic test data.

METHODS

A search of the English-language medical literature published between 1984 and 1994 retrieved 48 reports, 14 of which met the inclusion criteria. The analysis was limited to the aortoiliac and femoropopliteal segments because only two studies reported results of infrapopliteal arteries. Diagnostic performance of duplex and color-guided duplex, defined as the ability to detect a stenosis of 50-99% or an occlusion, was compared using summary ROC curve methodology. This method takes into account heterogeneity across studies attributable to differences in the threshold values used.

RESULTS

The summary ROC curves demonstrated a high level of diagnostic performance for both types of duplex imaging, with color-guided duplex scanning being superior (p = .022). For example, at a false-positive rate of .05 (specificity = .95), the analysis predicted a true-positive rate (sensitivity) of .83 for duplex alone and .93 for color guided duplex. Differences in the case mix of the study population and study design did not affect the results. Furthermore, sensitivity analysis did not reveal a strong effect of any single study on the results.

CONCLUSION

For aortoiliac and femoropopliteal arteries, the addition of color flow imaging to duplex scanning improves diagnostic performance in evaluating peripheral arterial disease.

Diagnosis of arterial disease of the lower extremities with duplex ultrasonography

The development of duplex scanning carries the prospect of an entire non-invasive work-up of patients with peripheral arterial occlusive disease. To obtain the best available estimates of its diagnostic accuracy, a meta-analysis of 71 studies evaluating duplex scanning was performed. Independent methodological judgement left 16 studies for data extraction. Pooled estimates (95 per cent confidence interval of sensitivity and specificity for detection of a stenosis greater than or equal to 50 per cent or occlusion in the aortoiliac tract were 86 (80-91) per cent and 97 (95-99) per cent respectively. The results for the femoropopliteal tract compared well with this, with a sensitivity of 80 (74-85) per cent and a specificity of 96 (94-98) per cent. The accuracy of detection of a stenosis greater than or equal to 50 per cent or an occlusion in the infragenicular arteries was lower with a sensitivity and specificity of 83 (59-96) per cent and 84 (69-93) per cent respectively. Duplex scanning is an accurate tool for assessment of atherosclerotic lesions in the aortoiliac and femoropopliteal tract and can replace routine preinterventional angiography in a substantial number of patients.

Iso-Osmotic Bowel Preparation Improves the Accuracy of Iliac Artery Colour Flow Duplex Examination

Colour flow duplex ultrasonography is currently the non-invasive method of choice for investigating the iliac arteries. However it is only 84–92% sensitive in the best hands when compared with biplanar angiography. Bowel gas and faeces overlying the iliac arteries obscure the vessels and prevent a good ultrasound image.

We have previously shown that preparation of the bowel with an iso-osmotic bowel preparation (Klean Prep) improves the clarity of duplex image of the iliac arteries. This is caused by a volume effect which flushes out gas and faeces, leaving a fluid-filled bowel transparent to ultrasound. The aim of this study was to investigate whether this enhanced image increased the diagnostic accuracy of duplex examination.

We performed iliac duplex examinations on 56 patients with clinically suspected iliac artery disease, initially with the normal preparation of starving the patients for 12 h and subsequently after preparation by Klean Prep. The results from each investigation were compared with the gold standard of biplanar intra-arterial digital substraction angiography.

The use of iso-osmotic bowel preparation (Klean Prep) significantly improved the accuracy of iliac duplex ultrasonography over preparation by 12 h starvation, when compared with biplanar angiography.

Postocclusive hyperaemic duplex scan: a new method of aortoiliac assessment

Aortoiliac duplex scanning, while accurate, is time-consuming and technically demanding. This study aimed to develop a fast, non-invasive screening test for aortoiliac disease. Colour duplex scanning was used to record common femoral Doppler ultrasonographic waveforms following 3 min of arterial occlusion using a thigh cuff in 25 patients with normal aortoiliac segments and 25 patients with significant aortoiliac disease. The latter patients had a prolonged period of postocclusive hyperaemic flow compared with the former. End diastolic velocity, 70 s after cuff release, was a significant discriminant between the two groups (sensitivity of 88 per cent, accuracy of 92 per cent). The postocclusive hyperaemic duplex (PHD) test performed well when used prospectively in a further 50 limbs (sensitivity of 86 per cent, accuracy of 84 per cent). The test was more sensitive than femoral pulse palpation and compared favourably with arteriography. The PHD test provides a simple, noninvasive assessment for aortoiliac disease that can be performed on the initial outpatient clinic visit.

Aortoiliac segment examination with colour flow Duplex--a pilot study using Klean Prep. to improve the image quality

OBJECTIVES

Currently colour flow Duplex examination of the iliac arteries is at best 84-92% sensitive. In an attempt to find a technique to improve on this sensitivity we have studied the effect of Klean Prep, an iso-osmotic bowel preparation, on the Duplex image and Doppler signal obtained when scanning iliac arteries.

METHODS

Twenty iliac segments in 10 arteriopaths were scanned by a blinded observer, after either starving for 12 h or having Klean Prep bowel preparation. Grey scale image, colour mapping and Doppler signal to noise ratios were scored on a linear analogue system. Each patient was subsequently rescanned after the other method of preparation and was once again scored by a blinded observer. The two sets of scores were then compared.

RESULTS

We found significant improvements in the linear analogue scoring of grey scale images, colour mapping and Doppler signal to noise ratios, when using Klean Prep as opposed to starving the patient prescan.

CONCLUSIONS

Preparing patients with Klean Prep before iliac Duplex examination improves the visualisation of these arteries.

Impact of ultrasonographic duplex scanning on therapeutic decision making in lower-limb arterial disease

Ultrasonographic duplex scanning has become a valuable diagnostic technique in detecting and grading stenoses and occlusions of the aortoiliac and femoropopliteal arteries. However, the question remains as to whether a treatment strategy can be designed without diagnostic angiography. This prospective study evaluated the impact of duplex scanning on therapeutic decision making. Patients with intermittent claudication, rest pain or ischaemic ulceration of the lower limb who were eligible for invasive treatment were studied. If treatment was considered necessary, a duplex scan was performed instead of diagnostic angiography. The surgeon made a therapeutic decision based on clinical assessment and information obtained from the duplex scan. If it was felt that duplex scanning gave insufficient information, diagnostic angiography was then performed. A group of 112 consecutive patients were studied prospectively; 12 were excluded for logistical reasons. The 100 remaining patients (intermittent claudication in 69, rest pain in 16, ischaemic ulceration in 15) were evaluated. Based on non-invasive tests 22 patients were treated conservatively, 36 were scheduled for percutaneous transluminal angioplasty (PTA) and 32 were scheduled for surgery. Angiography was requested to determine the definitive treatment policy in 28 patients: four of the 22 were scheduled for conservative treatment and 24 of the 32 were scheduled for surgery. All PTAs were performed without prior diagnostic angiography. Angiography was considered necessary in a further ten patients to formulate a therapeutic strategy. In 62 patients the treatment strategy could be determined without diagnostic angiography. Twenty-three of the 39 angiograms performed did not give additional information on treatment strategy. Integrated use of duplex scanning for the investigation of patients with arterial occlusive disease of the lower limb can reduce the need for diagnostic angiography.