REPLY BY THE AUTHORSWe entirely concur with the reviewer that chronic flank

pain is the most common distressing problem for patients withADPKD and that therapeutic options are limited. Althoughlaparoscopic cyst decortications may provide only partial re-lief with lingering peritoneal symptoms, ethanol-dominantcyst sclerotherapy in selected patients may be the only othersafe minimally invasive modality to offer this group of pa-tients.

Although we believe this procedure to be safe and mini-mally morbid, we admit that complications occurred in 2 ofour patients; however, we do not believe that these were di-rectly related to the procedure. In the patient who developed atemporary nephrocutaneous fistula, either one of the cystscould have already been infected or an inadvertent breach inthe aseptic barrier could have occurred. Had the possibility ofinfected cysts been recognized earlier in this patient, we couldhave placed a temporary percutaneous nephrostomy catheterduring the cyst sclerotherapy, which could have circumventedthis problem. In the other patient in whom the pain seemed tohave worsened after the procedure, it is possible that this wasrelated to the relentless and inevitable progression of the dis-ease with cysts that tend to reform and subsequently enlarge inother inaccessible portions of the kidney.

We again note that the precise impact of this therapeuticmodality on the long-term changes in blood pressure, renalfunction, and serum creatinine and other extrarenal aspects ofADPKD ought to have been studied. Because the pain scoreswere not evaluated for longer than 1 year, it was not possible tocomment on the durability of the pain relief; this was only ashort-term pilot study. We are also aware of the possibility thatethanol might have diffused into the adjacent renal paren-chyma and could have contributed to the apparent mildlyelevated creatinine values in the present study. However, thiswould require comparison and follow-up with a control groupof similarly matched patients in which another sclerotic agentsuch as N-butyl cyanoacrylate could be used. Such a studywould also need to take into account whether the apparent risein serum creatinine resulted from the treatment or diseaseprogression. Nevertheless, Lee and Lee1 (ethanol-based scle-rotherapy) and Kim et al.2 (n-butyl cyanoacrylate with iodized

oil-based sclerotherapy) have reported encouraging long-termresults with respect to relief of flank pain and improved serumcreatinine values, despite the problem of cyst recurrence in upto 14% to 36%.

We absolutely agree that a larger number of patients needsto be studied more objectively to define the precise role of thistherapeutic modality. We believe that offering absolute etha-nol-dominant cyst sclerotherapy for chronic flank pain is arelatively safe and minimally invasive outpatient option for aselect group of patients with ADPKD in whom laparoscopicsurgical deroofing has failed, is contraindicated, or the symp-toms have recurred postoperatively.

REFERENCES1. Lee YR, and Lee KB: Ablation of symptomatic cysts using

absolute ethanol in 11 patients with autosomal-dominantpolycystic kidney disease. Korean J Radiol 4: 239–242, 2003.

2. Kim SH, Moon MW, Lee HJ, et al: Renal cyst ablationwith n-butyl cyanoacrylate and iodized oil in symptomaticpatients with ADPKD: preliminary report. Radiology 226:573–576, 2003.

Iqbal Singh, M.Ch.(Urology)Division of Urology, Department of Surgery

University College of Medical Sciences, University of Delhi, andGTB Hospital

New Delhi, India

Gopesh Mehrotra, M.D.Department of Radiology

University College of Medical Sciences, University of Delhi, andGTB Hospital

New Delhi, India

doi:10.1016/j.urology.2006.07.002© 2006 ELSEVIER INC.

ALL RIGHTS RESERVED

488 UROLOGY 68 (3), 2006