A Major Complication in Micropercutaneous Nephrolithotomy: Upper Calyceal Perforation with Extrarenal Migration of Stone Fragments due to Increased Intrarenal Pelvic Pressure

Micropercutaneous nephrolithotomy is a safe and efficient technique for appropriate sized stones. It is performed through a 4.85 Fr all-seeing needle and stones are fragmented into dust, without the need for tract dilatation, unlike other percutaneous nephrolithotomy types. Even though micropercutaneous nephrolithotomy has many advantages, increase in intrapelvic pressure during surgery may cause rare but serious complications. Herein we report a case of micropercutaneous nephrolithotomy in a 20-year-old woman with a 20 mm right renal pelvis stone and present an undesired outcome of this complication, upper calyceal perforation. Right lower calyceal access was performed with 4.85 Fr all-seeing needle and 2 cm renal pelvis stone was fragmented by 272 μm Holmium-Yag laser system. Upper calyceal perforation and infrahepatic accumulation of stone fragments were detected by fluoroscopy during the surgery. Postoperative imagings revealed perirenal urinoma, perirenal and infrahepatic stone fragments, and lower calyceal stone fragments inside the system. On second postoperative day, minipercutaneous nephrolithotomy and double J catheter insertion procedures were applied for effective drainage and stone clearance. Risk of calyceal perforation and urinoma formation, due to increased intrapelvic pressure during micropercutaneous nephrolithotomy, should be kept in mind.