Efficacy of protected renal artery primary stenting in the solitary functioning kidney

Significant renal artery stenosis (RAS) in a solitary functioning kidney (SFK) represents one of the most acceptable indications for renal revascularization. Percutaneous transluminal renal artery stenting (PTRAS) is increasingly being used as a first line treatment for renal revascularization, associated with renal function improvement or stabilization in the majority of the patients with solitary kidneys, but also with deterioration in up to 38% of the cases. Atheroembolism during PTRAS has been postulated as a potential cause for this acute renal function worsening. The aim of this study was to report on the feasibility, safety, and early outcomes of PTRAS in a series of patients with SFK using distal embolic protection (DEP).

All PTRAS procedures in SFKs performed under DEP between June 2002 and September 2007 were reviewed. Renal function, blood pressure, and the number of anti-hypertensive medications were assessed pre- and post-intervention. Renal function improvement and deterioration were defined as a 20% increase and decrease in serum creatinine, respectively, compared with preoperative values. Primary and primary assisted patency rates were also calculated. Statistical differences between values before and after intervention were determined by the Student t test and statistical significance was taken at P < .05.

Protected PTRAS was performed in 14 patients with a SFK (9 men, 6 women, mean age 65.6 +/- 6.8 years). All patients were hypertensive and had varying degrees of azotemia. Mean pre-intervention stenosis degree was 86.8% +/- 7.8%. Immediate technical success was obtained in 100% of the patients. Renal function was cured (7.1%), improved (50%), or stabilized (42.9%) in all 14 (100%) patients after the procedure and no deterioration was noticed in any patient at 6-month follow-up. Pre- and postintervention serum creatinine levels were 3.01 +/- 1.15 mg/dL and 2.16 +/- 0.68 mg/dL, respectively, (P = .02). Hypertension was improved in 6 (42.9%) patients and stabilized in the remaining 8 (57.1%). Primary patency was 100% and 90% at 1 and 3 years, respectively, while primary assisted patency remained 100% for the whole follow-up period (mean, 31.8 +/- 19.4 months).

These findings suggest that in patients with a SFK, protected PTRAS represents a safe and effective treatment for halting the progression of renal dysfunction to renal loss and warrants further investigation.