Micropercutaneous Nephrolithotomy in the Treatment of Moderate-Size Renal Calculi Abdullah Armagan, MD, Abdulkadir Tepeler, MD, Mesrur Selcuk Silay, MD, Cevper Ersoz, MD, Muzaffer Akcay, MD, Tolga Akman, MD, Mehmet Remzi Erdem, MD, and Sinasi Yavuz Onol, MD Abstract Purpose: We present our initial experience with microperc in patients with moderate-size renal calculi. Patients and Methods: A retrospective analysis of 30 patients (male 14, female 16) with moderate-size (1–3 cm) kidney stones who underwent microperc between August 2011 and July 2012 was performed. The demographic values, perioperative and postoperative measures including age, stone size and location, body mass index, operative and fluoroscopy time, hemoglobin decrease, success and complication rates were prospectively re- corded into a patient entry system. Results: The average stone size was 17.9 – 5.0 mm (10–30 mm). The mean age of the patients was 41.5 – 18.2 years (range 3–69 years). The duration of the operation was calculated as 63.5 – 36.8 minutes (range 20–200 min). Mean fluoroscopic screening time was 150.5 – 90.4 seconds (range 45–360 seconds). The patients were discharged after a mean hospitalization period of 35.5 – 18.6 hours (range 14–96 hours). An overall success rate of 93% (including 10% of insignificant residual fragment rate) was achieved. In the follow-up, residual stone fragments were detected in two (7%) patients. Conversion to miniperc was necessitated in three (10%) patients. The mean hemoglobin drop was found to be 1.1 – 0.8 mg/dL (range 0–2.8 mg/dL). Complications were observed in five (13.3%) patients. Conclusions: Our initial results provide that microperc is a feasible, safe, and efficacious treatment modality for moderate-size kidney stones as well as small ones with its minimally invasive nature. Technical refinements are needed to achieve better results and overcome the limitations of technique. Introduction R enal stone disease is a common health problem that may lead to significant morbidity and mortality if left untreated. Since the introduction of the percutaneous ne- phrolithotomy (PCNL), there had been a critical shift from open surgery to endoscopy in the treatment of patients with the disease. 1 Today, PCNL is accepted as the gold standard treatment modality for large renal calculi. 2 With the technologic advances of the endolithotripters and miniaturization in the instrument size, different treatment modalities such as flexible ureterorenoscopy and miniperc have been popularized in the management of small and/or medium sized renal calculi. 3–6 Despite the high success rate of PCNL, the complication rates are reported in the range of 29% to 83% in different series. 7,8 Bleeding may sometimes be a worrisome complica- tion that generally occurs during tract dilation. Therefore, to prevent hemorrhage, the idea of using less traumatic and finer instruments has led to the improvement of novel devices. Micropercutaneous nephrolithotomy (microperc) has recently been introduced as a treatment modality in which percutaneous renal access is achieved under direct vision using a specialized optical puncture system called ‘‘all- seeing needle’’ (Figs. 1, 2). 9 The main advantage of this technique is its smaller size and the single-step performance without the necessity of tract dilation. Desai and associ- ates 10 have just published their initial experience with this modified PCNL technique in 10 patients with renal calculi with a mean size of 14.3 mm. Recently, Tepeler and colleagues 11 presented the feasibility of microperc in the management of symptomatic lower pole renal calculi, which is a challenging issue. No study has been conducted, however, regarding the management of moderate-size stones until now. We present our initial experience with microperc in patients with moderate-size renal calculi. To our knowledge, this is the first and the largest clinical study introducing the safety and feasibility of this new modality in relatively large- size kidney stones. Department of Urology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey. JOURNAL OF ENDOUROLOGY Volume 27, Number 2, February 2013 ª Mary Ann Liebert, Inc. Pp. 177–181 DOI: 10.1089/end.2012.0517 177