Endourologic and Retroperitoneoscopic Combined Mininvasive Management of Cystine Urolithiasis in an Infant of 13 Months of Life.

Background: There are limited data about urolithiasis in young infants, especially in class age younger than 2 years. Case presentation: We report the case of a child <2 years old (13 months) affected by metabolic urolithiasis (cystinuria), and renal hypertension. He was admitted to our ward from the pediatric emergency room for fever, lack of appetite, irritability, and abdominal pain crisis. Ultrasonography (US) described a huge stone (15 mm) in dilated left renal pelvis (20 mm) associated with distal ureteral ectasia (7 mm). Urine and blood diagnostic assessments were performed. Hydropenic therapy and urine alkalization were started without success. The child underwent an ureteroscopy (URS) with a 4.5-6.5F rigid ureteroscope aiming to reach the renal pelvis and perform holmium: yttrium-aluminum-garnet laser stone disintegration. During the procedure, the ureter presented two unexpected stones in the distal portion (missed on US). A laser ureteral lithotripsy was effectively performed extracting smaller stone fragments. Ureteral kinking, confirmed by ascending pyelography, made it impossible to reach renal pelvis with the ureteroscope. The child was further studied with a CT scan that revealed a massive stone involvement of the left excretory pathway. Metabolic and urine assessment revealed a metabolic disease: cystinuria. To remove renal stones, an operative retroperitoneoscopy (RP) was performed. During the procedure was identified a lesion of the pelvis (secondary to stone decubitus) with urine tearing and massive perirenal inflammation. The stone was removed and pelvis was sutured. Postoperatively, the patient was stone free without major complications. Conclusions: In particular cases (younger patients, ureteral kinking, and renal failure risk), a totally combinated minimally invasive access (URS, laser stone fragmentation, and RP) can be a valid alternative to micro percutaneous nephrolithotomy or to massive open treatment. In fact, rigid URS represents a valid minimally invasive approach either for examination or for laser treatment of pediatric urinary tract stones. With important ureteral kinking, RP must be considered by experienced pediatric urologists. Copyright 2020, Mary Ann Liebert, Inc., publishers.