Report from SIR: Laser bursts clear renal stent restenosis

Pulsed ultraviolet lasers reduce the occurrence of renal artery in-stent restenosis and its related risks, according to a study presented at the Society of Interventional Radiology meeting in New Orleans.

Excimer laser renal angioplasty (ELRA) starts as any standard percutaneous transluminal angioplasty procedure. After the guidewire is set in place, the interventionalist introduces the ELRA catheter (Spectranetics, Colorado Springs, CO). This bundles very thin, flexible optical fibers and ablates the artery blockage with bursts of ultraviolet laser.

The specialist repeats the process until all stenosis sites are cleared. Successive angiography reveals whether postprocedure percutaneous transluminal angioplasty is necessary.

Dr. David E. Allie and colleagues at the Cardiovascular Institute of the South in Lafayette, LA, enrolled 44 patients with more than 60% in-stent renal artery restenosis. All patients underwent ELRA.

The procedure included pre- and postprocedural angiography, catheter pressure gradients, and follow-up at one-week, one-month, and six-month intervals. The investigators found ELRA safe to treat renal artery in-stent restenosis.

Allie, director of cardiothoracic and endovascular surgery at the CIS, recorded a technical success rate of 97%. Patients' arterial pressure gradients dropped, on average, from 30 mm Hg to 4 mm Hg. In-stent restenosis dropped from a mean 78% to 10%. Nearly 14% of patients required a new stent inside an existing one, however, a procedure known as a stent sandwich, early in the trial.

More experienced physicians were able to reduce the stent sandwich rate to less than 10% in the last 16 procedures. Four patients developed in-stent restenosis at six months, but they remained restenosis-free for the next six months following repeat ELRA without stenting.

Current in-stent restenosis rates range from 12% to 39%, troubling physicians. ELRA helps reduce angioplasty constraints, since the reopened artery is easier to access and more receptive to balloon inflation, Allie said.

ELRA avoids unwanted contact with sensitive structures, such as the abdominal aorta, he said. All catheter manipulation is done in the thoracic aorta, and physicians can use bony landmarks for safe catheter guidance, manipulation, contrast usage, and aspiration of debris.

"Currently, there is no consensus as to how we are going to treat these patients," Allie said. "The photoablative debulking capabilities of this technology can eliminate the need for stent sandwiches and help reduce problems and risks."

For more information from the Diagnostic Imaging archives:

CTA builds reputation in peripheral disease

Renal artery stenting scores good grades in trials

Imaging and stenting provide effective therapy

CT angiography offers noninvasive evaluation of renal arteries