ENDOUROLOGY & LAPAROSCOPY

Renal cryoablation: outcome at 3 years
Gill IS, Remer EM, Hasan WA, Strzempkowski B, Spaliviero M, Steinberg AP, Kaouk JH, Desai MM, Novick AC
Section of Laparoscopic and Minimally Invasive Surgery, Glickman Urological Institute and Department of Radiology, Cleveland Clinic Foundation, Cleveland, Ohio, USA
J Urol. 2005; 173: 1903-7

• Purpose: We report intermediate term oncological followup data on 56 patients undergoing laparoscopic renal cryoablation, of whom each completed a 3-year followup.
• Materials and Methods: Since September 1997, 56 patients undergoing laparoscopic renal cryoablation have completed a followup of 3 years each. The postoperative followup protocol comprised serial magnetic resonance imaging (MRI) at 1 day, months 1, 3, 6, 12, 18 and 24, and yearly thereafter for 5 years. Computerized tomography guided needle biopsy of the cryolesion was performed 6 months postoperatively and repeated if MRI findings were abnormal. Followup data were obtained prospectively.
• Results: For a mean renal tumor size of 2.3 cm mean intraoperative size of the created cryolesion was 3.6 cm. Sequential mean cryolesion size on MRI on postoperative 1 day, and at 3 and 6 months, and 1, 2 and 3 years was 3.7, 2.8, 2.3, 1.7, 1.2 and 0.9 cm, representing a 26%, 39%, 56%, 69% and 75% percent reduction in cryolesion size at 3 and 6 months, and 1, 2 and 3 years, respectively. At 3 years 17 cryolesions (38%) had completely disappeared on MRI. Postoperative needle biopsy identified locally persistent/recurrent renal tumor in 2 patients. In the 51 patients undergoing cryotherapy for a unilateral, sporadic renal tumor 3-year cancer specific survival was 98%. There was no open conversion, kidney loss, urinary fistula, dialysis requirement, or perirenal or port site recurrence in any patients.
• Conclusions: Three-year outcomes following renal cryoablation are encouraging. Longer term (5-year) data are necessary to determine the proper place of renal cryotherapy among minimally invasive, nephron sparing options.
  
  
• Editorial Comment
  Minimally invasive ablative techniques are becoming more popular and longer clinical data have been demonstrated by different centers.
  The technology seems to ablate the renal cancer cells efficiently and the surgical technique offers comparable complication rates to other nephron-sparing techniques. Not surprisingly, this method of renal mass ablation preserves renal function adequately. As the authors concluded longer clinical follow-up is needed.

Dr. Fernando J. Kim
Assistant Professor of Urology
University of Colorado Health Sciences Center
Denver, Colorado, USA