The role of duplex scanning in decision making for patients with claudication

Decision making in the treatment of peripheral arterial disease - A single-institution comparative study using information from color doppler and digital subtraction angiogram studies

Background:

Numerous studies have compared the accuracy of color Doppler (CD) with that of digital subtraction angiography (DSA) in the diagnosis of peripheral arterial disease (PAD). However, only a few have looked at the influence of these diagnostic tests on the treatment decision in PAD.

Aim:

This study evaluated the differences in treatment decisions that were based on CD and with those based on DSA findings.

Methods and Materials:

Findings from CD and DSA studies obtained in 40 patients were entered on line diagrams by two radiologists working separately. These were randomized and sent to three experienced clinicians – two vascular surgeons and one interventional radiologist. The treatment decisions of the clinicians based on each proforma were collected and analyzed to look for the degree of agreement between Doppler-based and DSA-based decisions.

Results:

There was fair to moderate agreement between CD-based and DSA-based decisions for all three clinicians, with some improvement in agreement with the addition of clinical data. The vascular surgeons showed better agreement with each other on treatment decisions compared to the interventional radiologist who showed a fair-to-moderate level of agreement with the vascular surgeons, which did not significantly change with the addition of clinical data.

Conclusion:

There is a fair to moderate agreement between treatment decisions based on CD findings and those based on DSA findings. We conclude that CD along with clinical data is sufficient to make decisions in the treatment of PAD.

Cost-effectiveness of identifying aortoiliac and femoropopliteal arterial disease with angiography or duplex scanning

OBJECTIVES

Cost-effectiveness analysis of three diagnostic imaging strategies for the assessment of aortoiliac and femoropopliteal arteries in patients with peripheral arterial occlusive disease. The strategies were: angiography as the reference strategy, duplex scanning (DS) plus supplementary angiography (S1) and DS plus confirmative angiography (S2).

DESIGN, MATERIALS AND METHODS

A decision model was built with sensitivity and specificity data from literature, supplemented with prospective hospital cost data in Euro (euro). The probability of correctly identifying the status of a lesion was taken as the primary outcome. We compared strategies by assessing the extra costs per additional correctly identified case.

RESULTS

Assuming no false positive or false negative results, angiography is the most effective strategy if the prevalence of significant obstructive lesions in the aortoiliac and femoropopliteal tract exceeds 70%, or if the sensitivity of duplex scanning is lower than 83%. In case of lower prevalence, strategy S1 becomes equally or even more effective than angiography. At a prevalence of 75%, performing angiography costs euro 8443 per extra correctly identified case compared with strategy S1.

CONCLUSIONS

In most situations angiography is more effective than diagnostic strategy S1. However, if society is unwilling to pay more than euro 8443 for knowing a patient's disease status, diagnostic strategy S1 is a cost-effective alternative to angiography, especially at lower prevalence values.

Duplex ultrasonography rarely changes management decisions in chronic lower extremity ischemia

The purpose of this study was to determine the proportion of patients presenting with lower extremity pain whose treatment plan was altered by duplex ultrasonography. This prospective study evaluated all patients referred for lower extremity pain who had undergone a lower extremity arterial duplex scan. All patients underwent a history and physical examination by the same vascular surgeon. After the completion of the history and physical examination, the surgeon established a preliminary treatment plan. Subsequently, he reviewed the lower extremity duplex results and established a final treatment plan based on the history, physical examination, and duplex results. Treatment was labeled as either (1) conservative, (2) aggressive, or (3) the patient was considered to have no peripheral vascular disease. The proportion of patients whose primary treatment plan was altered by the addition of duplex ultrasonography was determined. Of 103 patients who entered the study, 7% had no peripheral vascular disease based on the history, physical examination, and duplex scan. Based on the history and physical examination alone, 48.5% were to be treated conservatively and 44.7% aggressively. After reviewing duplex results, the treatment plan was changed in only 5.9% of patients. There was no difference in treatment plan after the addition of the duplex results (p = 0.1025). Duplex ultrasonography remains a valuable tool in the evaluation of patients with lower extremity peripheral vascular disease; however, in most patients, the decision to treat conservatively or aggressively can be made without duplex scanning. All patients referred to the vascular clinic for lower extremity evaluation do not require a duplex scan.

[Significance of the determination of Doppler sonography haemodynamic indices for the assessment of distal perfusion in patients with critical ischemia of lower limbs]

BACKGROUND/AIM

The perfusion of tissue, especially the muscles of the lower limbs (LL), implies the blood flow that carries enough nutrition, energy materials and oxygen. The aim of this study was to determine whether the decreased Doppler sonography parameters, resistence index (RI), and pulsatility index (PI) were significant as indicatiors of irreversible ischemia of LL.

METHODS

In 40 patients (mean age 66 +/- 14.9 years, 21% women and 79% men) with the signs of critical ischemia of LL, Lariche-Fontaine class III and IV, we performed contrast angiography of the LL arteries, and perfusion scintigraphy of LL using, thallium-201, while we performed Doppler sonography to determine resistance index (RI), as well as pulsatility index (PI). After that, all the patients were treated with vasodilatation using Bergmann's solution within a 10-day period. Following that, all the patients underwent the determination of haemodynamic indices RI and PI applying the methods of Doppler sonography. The obtained values of RI and PI indices revealed no clinical recovery which suggested the irreversibility of critical ischemia (unsuccessful therapy in 100% of the patients), and clinical recovery which suggested the reversibility of the disease (unsuccessful therapy in 80% of the patients).

RESULTS

The obtained values of PI = 0-0.3 and RI = 0-0.25 for the examined LL arteries were the indicators of irreversible ischemia. A significant correlation between the values of RI in the distal parts of a. tibialis anterior and posterior was proved, as well as between the decreased perfusion of LL determined by tallium-201 (p < 0.05, r = 0.43), and a tibialis anterior (p = 0.05, r= 0.38). There was, however, no statistically significant correlation between the angiographic values and perfusion scintigraphy of LL.

CONCLUSION

The obtained values of haemodynamic RI and PI indices should be a novel approach for introducing a new criteria for the assessment of reversible and irreversible critical ischemia of LL using the method od Doppler.

Measurement, calculation, and normal range of the ankle-arm index: a bibliometric analysis and recommendation for standardization

Since its introduction in 1950, a variety of methods of measurement and calculation have been used to establish the ankle-arm index (AAI). This has resulted in variations of its normal range and difficulty in comparing study results. Hence, the objective of our study was to analyze the disparate methods used to assess AAI and its normal range and to recommend a standardized method to assess AAI based on that analysis. We made an inventory of the disparate AAI methods and its normal range reported in 100 randomly selected publications and recommend the means of such standardization. We recommend that an experienced observer assess AAI with the patient at rest in the supine position. The width of the sphygmometer cuffs should be 1.5 times that of the extremity to be measured, and brachial and crural pulses should be detected using a Doppler device. Systolic pressures should be measured at both arms and over the anterior and posterior arteries of both legs, with the cuff placed just proximally to the malleoli. The left arm pressure ought to be used as denominator and the mean of pressures of both crural arteries of each leg ought to be used for the numerator of the AAI for that leg. We advocate 0.90 as the cut-off value to distinguish patients who need further arterial assessment.

Ankle-arm index versus angiography for the preassessment of the fibula free flap

Peripheral arterial occlusive disease or congenital anomalies of the major crural arteries may limit the use of the fibula free flap and should be detected preoperatively. Conventional selective angiography is the definitive standard imaging method for making this diagnosis, but it has drawbacks. A safer, cheaper, more accurate, and noninvasive alternative is desirable. The authors sought to test the hypothesis that the ankle-arm index of each of the three crural arteries, combined with pencil Doppler examination of the peroneal skin perforators, would provide adequate information to restrict the use of angiography to cases in which the outcomes of either or both of these options are insufficient. The ankle-arm index data of each of the three crural arteries, as well as pencil Doppler examination of the peroneal skin perforators of both legs of nine prospectively included patients and the nonoperated legs of 13 retrospectively included patients, were compared statistically in four different ways with the preoperative angiographic findings. A combined ankle-arm index and pencil Doppler examination is not accurate enough to detect legs or arteries with subclinical peripheral arterial occlusive disease or vascular variation and, hence, is not a sufficient basis on which to develop the surgical plan for a fibula free flap.

Early results of infragenicular revascularization based solely on duplex arteriography

PURPOSE

Recent reports have both advocated and questioned the utility of duplex arteriography (DA) as the sole preoperative imaging modality for planning infragenicular revascularization. This study compares the outcome of patients with critical limb ischemia who underwent infragenicular vein grafts on the basis of DA alone versus conventional preoperative contrast arteriography (CA).

METHODS

The study group is composed of 23 consecutive patients who underwent infragenicular vein bypass grafting solely on the basis of preoperative DA from 1998 to 1999. They were compared with 50 consecutive patients who underwent infragenicular vein bypass grafting after CA from 1996 to 1998. Peak systolic velocity and end-diastolic velocity of potential target arteries were recorded during DA studies. In situ saphenous vein grafts were used preferentially, and technical adequacy of all grafts was assessed with completion duplex or arteriography.

RESULTS

DA and CA groups were comparable on the basis of age and risk factors. In one limb (4%), the target artery selected by DA was abandoned because of dense calcification. No other revision in target or inflow artery was required on the basis of intraoperative completion studies. At 1 year, primary graft patency (78% vs 70%, P =.72) and limb salvage (70% vs 81%, P =.21) were comparable between the two groups. In the DA group, mean preoperative target artery peak systolic velocity in patent versus failed grafts was 49 +/- 18 cm/s versus 31 +/- 9 cm/s (P =.04), whereas mean end-diastolic velocity was 22 +/- 7 cm/s versus 14 +/- 8 cm/s (P =.08).

CONCLUSION

Infragenicular revascularization directed by DA alone provides early graft patency and limb salvage rates comparable to similar procedures that are based on CA. Preoperative DA target artery velocities may predict outcome and improve target selection. These initial results justify further clinical testing of DA as the primary imaging modality for planning infragenicular vein grafts.