Anterograde Mini-Percutaneous Retropelvic Extra-Luminal Endopyelotomy: A Novel Approach to Uretero-Pelvic Junction Obstruction.

Background Uretero-pelvic junction obstruction (UPJO) is a common cause of upper tract urinary obstruction. This condition is generally treated with various surgical options which include endoscopic (retrograde or anterograde), laparoscopic, open or robotic-assisted approaches. Herein, we describe a novel endoscopic retropelvic extra-luminal approach using a mini (14 Fr) nephroscope. Methods A 30-year-old male presented with symptomatic left UPJO and inferior pole renal stones, which were identified on computed tomography (CT) imaging. Mercaptuacetyltriglycine (MAG3) renogram demonstrated a functioning left kidney. With the patient positioned supine, a mini-perc (Karl-Storz) nephroscope was used to access the renal pelvis via the percutaneous route. The retropelvic space was thereafter accessed. Using a Holmium-YAG laser, the UPJO was splayed using an extra-luminal approach. Results Clear endoscopic vision, minimal bleeding, and overall satisfactory identification of the UPJO were achieved. At the 12-month follow-up, the patient remained stent and symptom-free. On follow-up CT imaging and MAG3 renogram, the system remained dilated with no obstruction noted. Conclusion Percutaneous anterograde retropelvic extra-luminal endopyelotomy is a novel approach that should be considered in patients with secondary renal calculi. This is the first report of the procedure being successfully performed utilizing the mini-perc access route.