Flexible ureteroscopy with ultrasound guidance for the treatment of parapelvic renal cysts: A complementary approach for locating the cystic wall

A rare case of parapelvic cyst: A case report

Parapelvic cyst (PPC) is a rare cyst that arises from the renal parenchyma and usually does not cause symptoms. However, PPC may cause compression of the pelvicalyceal system resulting in obstructive symptoms. Ultrasonography may not be sufficient to diagnose PPC since they are often misdiagnosed with hydronephrosis, thus computed tomography of the renal is required. In this case, we present, a 27 years old male with a 3 years history of partial urinary retention presented with intermittent loin pain. Hydronephrosis was found on ultrasonography but failed to identify the source of obstruction. A CT scan was conducted and a PPC was confirmed. Nephrostomy was scheduled for ureteral dilation and the patient responded well 4 months after surgery. In this case, we highlight the role of radiology in identifying and differentiating the PPC.

Clinical efficacy of intraoperative real time ultrasound-assisted flexible ureteroscopic holmium laser incision and internal drainage in the treatment of parapelvic cysts

Objective

This study aims to investigate the efficacy and safety of intraoperative real time ultrasound-assisted flexible ureteroscopic holmium laser incision and internal drainage in the treatment of parapelvic cysts, and to review recently published relevant literature.

Method

This is a retrospective study in which the clinical data of 47 patients who underwent flexible ureteroscopic holmium laser incision and internal drainage of parapelvic cysts in our center from March 2017 to March 2021 were retrospectively analyzed. A literature search was conducted to review and summarize relevant reports on endoscopic treatment of parapelvic cysts published in the past 10 years.

Results

Among 47 patients with parapelvic cysts who underwent flexible ureteroscopic holmium laser incision and internal drainage, 12 (25.53%) cases had a typical cyst wall bulging into the collecting system under flexible ureteroscope. As the cyst wall was thin and translucent in these cases, ultrasound was not used during the operation. The cysts of the remaining 35 patients were located with the aid of intraoperative real time ultrasound, and all underwent successful operation. No serious surgical complications occurred after surgery. The patients were followed up for 12–24 months after operation. The cyst in one case was observed larger than its original size before operation, so recurrence was considered. In another two cases, the diameters of the cysts were more than half of their original diameters before operation. Thus, the efficacy was poor in the three cases. For the remaining 44 cases, there was no obvious cyst observed or the diameter of the cysts was less than half their preoperative level.

Conclusion

The approach of ultrasound-assisted flexible ureteroscopic holmium laser incision and internal drainage in the treatment of parapelvic cysts is safe and effective, which helps to solve the problem of localization of atypical parapelvic cysts on endoscopic findings.