[Endoscopic marsupialization of parapelvic renal cysts].

Introduction: Parapelvic renal cysts are very common. Indications for surgical treatment are upper urine tract obstruction, pain and recurrent gross hematuria.

Aim: To analyze the efficiency and safety of endoscopic transurethral and percutaneous laser marsupialization of parapelvic renal cysts.

Materials And Methods: A total of 9 patients were undergone to transurethral intrarenal marsupialization of parapelvic renal cysts from March 2016 to February 2021 (4 men, 5 women, aged 42-78 years). Another 2 patients (2 men, aged 46 and 52 years) were treated by percutaneous approach. The average size of the cyst according to contrast-enhanced multi-slice computed tomography (MSCT) was 3.1+/-1.8 cm. In two cases, papillary tumor of the pelvis was suspected. The anteroposterior diameter of the pelvis was 2.6+/-1.3 cm; 9 patients had pain in the loin area, while in 7 patients recurrent gross hematuria was also an indication for surgical treatment. For marsupialization, a holmium (Ho:YAG) laser Auriga XL (Boston Scientific, USA) was used in 4 patients, and in other cases (n=7) a procedure was performed using a thulium fiber laser (Tm Fiber) Fiberlase U1 (IRE-Polus, Russia). In 3 patients, to clarify the site of incision of the cyst, intraoperative ultrasound was used. In all cases, after draining the cyst, an internal stent was placed inside the cyst for a period of 4-6 weeks.

Results: The duration of transurethral surgery was 26+/-11 minutes, while percutaneous marsupialization of the cyst, which was performed in combination with percutaneous nephrolithotomy, took 10 and 18 minutes, respectively. The average catheterization time was 12+/-8 hours. Nephrostomy tube was removed on the 2nd day. The length of stay was 4+/-2 days. Febrile fever was noted in 1 patient (9%), which required a change in antibiotic therapy. During ultrasound control at discharge, the dilatation of the collecting system was not detected in any cases, while the residual cavity was found in 2 patients (18%). Follow-up contrast-enhanced MSCT and ultrasound within 3-30 months in all patients (n=11) showed no dilatation of the collecting system. In 1 (9%) patient, the residual cavity was preserved with a decrease in size to 1.2 cm without signs of upper urinary tract obstruction; the initial diameter of the cyst in this patient was 4.9 cm. There was no recurrence of gross hematuria.

Conclusions: In our opinion, transurethral and percutaneous laser marsupialization of parapelvic renal cysts is an effective and safe method that allows definitive treatment for cysts up to 4 cm in size. If the cyst is larger than 4 cm, endoscopic removal should be balanced with the possibility of preserving the residual cavity. The most common complication of endoscopic treatment of intrarenal cysts is acute pyelonephritis with a rate of 9%.