Color-Flow Duplex Hemodynamic Assessment of Runoff in Ischemic Lower Limb Revascularization

Duplex Ultrasound as a reliable alternative to CT angiography for treatment planning of Peripheral Artery Disease

BACKGROUND

The aim of this work is to compare the diagnostic accuracy of Duplex ultrasound (DUS) and CT angiography (CTA) in the study of arterial vessels, in patients with chronic peripheral arterial disease (PAD) of the lower limbs to undergo endovascular revascularization with the use of intraprocedural digital angiography (DSA).

METHODS

94 patients with obstructive pathology of the arterial axes of the lower limbs were enrolled in the study. In all patients, endovascular revascularization treatment was considered the most suitable therapeutic choice. For this reason, ultrasound and CTA was performed preoperatively in all and based on the data obtained it was decided to classify the arterial tree into five segments: iliac, common femoral, superficial femoral, popliteal and infra-geniculate. According to the degree of stenosis or occlusion, the arteries were scored in no stenotic, stenotic and occluded. The comparison of the data provided by the DUS and the CTA was carried out with reference to the parameters obtained by the DSA.

RESULTS

The results of our experience have shown that in the iliac arterial district DUS proved to be less accurate than CT angiography when compared to DSA (Cohen's Kappa agreement of 0.91 and 1.0, respectively). Good diagnostic concordance were found in the femoro-popliteal district (Cohen's Kappa agreement 33 between 0.96 and 0.93). On the contrary, when the data of the infra-geniculate area were compared, CT angiography showed a net deficiency compared to DSA and DUS (Cohen's k: 0.75).

CONCLUSIONS

Due to its accuracy, high-quality DUS performed by well-trained operators may therefore represent a good alternative to CTA in patients undergoing endovascular revascularization, in order to reduce the use of contrast-enhanced radiological imaging especially when a condition of intolerance to the contrast medium and/or renal insufficiency coexists.

Duplex ultrasound versus CT angiography for the treatment planning of lower-limb arterial disease

PURPOSE

This study aimed to assess the diagnostic accuracy of duplex sonography (DUS) compared with that of computed tomography angiography (CTA) in detecting occlusion and stenosis in peripheral arterial disease (PAD) in candidate patients for endovascular revascularization with intraprocedural digital subtraction angiography (DSA).

METHODS

The study involved 94 patients suffering from PAD who were candidates for endovascular procedures requiring DSA. They were all submitted preoperatively to DUS and CTA. Based on image analysis, five segments of the arterial tree were assessed: iliac, common femoral, superficial femoral, popliteal, and infrageniculate. According to the stenosis or occlusion degree, the arteries were rated as nonstenotic, stenotic, and occluded.

RESULTS

The agreement between DUS and CTA findings using DSA as a reference modality was expressed as a Cohen's kappa (κ) statistic agreement. Our results show that DUS has been less accurate than CTA in evaluating iliac arterial diseases (Cohen's κ agreement of 0.91 and 1.0, respectively) when measured against DSA. We found good diagnostic concordance between DUS and DSA in detecting hemodynamic stenosis and occlusion of the femoro-popliteal axis (Cohen's κ agreement between 0.96 and 0.93). Below the knee, CTA showed even less concordance with DSA (Cohen's κ 0.75).

CONCLUSIONS

Because of its accuracy, high-quality DUS performed by well-trained operators may therefore represent a good alternative to CTA in patients undergoing endovascular revascularization to minimize the use of contrast-enhanced radiological imaging. Nevertheless, preoperative CTA imaging is required in cases of nondiagnostic DUS or when a more complete overview of the vascular tree is needed for complex invasive interventions.

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.

Reliability of preoperative duplex scanning in designing a therapeutic strategy for chronic lower limb ischemia

The objective of this study was to compare the treatment plan designed on the basis of preoperative duplex scanning evaluation of the critical limb ischemia with the treatment plan finally carried out, after assessing the findings obtained during surgical or endovascular treatment. Over a period of 51 months a preoperative duplex scanning study was carried out in 335 consecutive patients with chronic critical ischemia, to design the best therapeutic strategy. Agreement between both plans were as follows: 80%, 82,7% and 59% in the examinations of the iliac arteries, femoropopliteal or tibial arteries respectively. The operation plan was more frequently modified due to a duplex scanning failure in procedures involving the the distal vessels(10 of 44 [22.7%], p < 0.01). In conclusion, duplex scanning evaluation of patients with occlusive arterial disease of the lower limbs permits the design of both a medical and a surgical or endovascular treatment plan with a high level of agreement with the findings obtained during the revascularization procedure.