Duplex eliminates exposure to radiation


According to research by Dr Enrico Ascher, The Vascular Institute, Maimonides Medical Center, Brooklyn, NY, durable balloon angioplasties can be done without exposure to contrast material or radiation, when performing endovascular treatment of occlusive and stenotic lesions of the femoral-popliteal arterial segment. The study is featured in the December 2006 issue of the Journal for the Society of Vascular Surgery.

The researchers noted that open bypass operations are more durable in the long-term, however when performed by endovascular means, resulting in the use of fluoroscopy (radiation exposure) and contrast material, such exposure sometimes causes severe allergic reactions or kidney failure, with the risk of kidney damage is increased in diabetic patients. According to the study, this exposure is unnecessary as in many cases duplex scanners rather than X-rays can be employed.

In this study 196 patients (ages 42 to 97) had a total of 253 attempted balloon angioplasties of the superficial femoral (SFA) and/or popliteal arteries under duplex guidance in 218 limbs. Critical ischemia was indicated in 38% of cases and disabling claudication was in 62% t. Conditions that presented and percentages of the total patients were: hypertension, 78; diabetes, 51; chronic renal insufficiency, 41; smoking, 39 and coronary artery disease 37.

Under direct duplex visualization, the common femoral artery is cannulated and a guide wire is directed into the proximal SFA across the diseased segments; it is then parked at the tibio-peroneal trunk. Diseased segments are then balloon dilated, with the balloon’s diameter and length chosen according to measurements obtained through duplex scan. Hemodynamically significant defects causing diameter reduction more than 30% and peak systolic velocity ratio more than two were corrected with a variety of self-expandable stents under duplex guidance.

Overall technical success of the duplex guided method was 93% (236 of 253 cases). Overall limb salvage rates were 90 and 94% at six and 12 months, respectively. Intraluminal stents were placed in 65% of successful cases and end-stage renal disease was the only significant predictor of subintimal dissection failure in patients with femoral-popliteal occlusions (five of 17 cases).

Researchers reported that the technical advantages of duplex-guided treatment include direct visualization of the puncture site, accurate selection of the proper size balloon and stent, and confirmation of the adequacy of the technique by hemodynamic and imaging parameters. “In addition to patient safety, this modality helps minimize the vascular surgeon’s exposure to radiation, which can cause conditions such as impaired vision, skin damage and infertility,” commented Ascher.

Date: Feb/2007