Impact of the rapid-exchange versus over-the-wire technique on procedural complications of renal artery angioplasty

Purpose: To investigate whether the use of rapid-exchange (RX) systems adds to the safety of percutaneous renal artery procedures compared to the conventional over-the-wire (OTW) technique. Methods: The interventional registry in our department was interrogated to identify patients who underwent plain balloon angioplasty and/or stent implantation for > 60% renal artery stenosis and intractable hypertension or decreasing renal function between 1998 and 2004. In this time period, 63 consecutive patients (36 men; mean age 67 years, range 57-80) underwent 78 renal artery angioplasty procedures. The first 46 procedures were done using a transfemoral OTW technique via 7-F sheaths; the following 32 procedures were performed with an RX system via a transfemoral 6-F access. Duration of fluoroscopy, amount of contrast agent, course of serum creatinine, and complications were compared between OTW and RX approaches. Results: Duration of fluoroscopy (median 13.1 versus 11.1 minutes, p = 0.099) and primary technical success (94% versus 97%, p = 0.64) were not significantly different between the OTW and RX approaches, but significantly less contrast agent was needed with the RX system (median 215 versus 140 mL, p < 0.001). Complications, all minor, occurred significantly more often with the OTW (11/46, 24%) compared to the RX system (2/32, 6%; p = 0.040) and included misplaced stents, prolonged severe hyper/hypotension, transient renal impairment, and puncture site complications. In particular, the rates of increased serum creatinine within 24 hours were higher in the OTW patients compared to the RX group (20% versus 3%, respectively, for > 25% increase [p = 0.041] and 9% versus 0% for > 50% increase [p = 0.087]). Conclusions: Rapid exchange systems seem to add to the safety of percutaneous renal artery interventions. This likely may be due to a variety of causes, including lower doses of contrast medium, shorter duration of fluoroscopy, and smaller device diameters.