Subcapsular renal haematoma after ureteroscopic lithotripsy: a single-centre, retrospective study in China.

Objectives: To investigate the incidence, predisposing factors, diagnosis and management of subcapsular renal haematoma (SRH) after ureteroscopic lithotripsy (URSL).

Design: Retrospective observational study.

Setting: Shandong Provincial Hospital, a 4500-bed tertiary hospital in China.

Participants: The data from 1535 consecutive patients treated with URSL (including rigid URSL and flexible URSL) between January 2015 and October 2020 were retrospectively analysed.

Main Outcome Measures: SRH after URSL confirmed via CT. The characteristics, operative data and outcomes of these patients were documented and compared.

Results: Six patients were confirmed to have an SRH after URSL on CT. The total incidence of SRH after URSL was 0.39%. The incidences of SRH after rigid URSL and flexible URSL were 0.38% and 0.41%, respectively. Unendurable ipsilateral flank pain and a significant decrease in haemoglobin after surgery were the typical clinical manifestations of SRH after URSL. There were no significant differences in age, sex, history of diabetes mellitus, preoperative hypertension, body mass index, stone laterality or perfusion pressure (p>0.05). However, SRH was significantly associated with the stone size, stone location, degree of hydronephrosis and operative duration (p<0.01). One patient was managed conservatively without further intervention, percutaneous drainage was performed in four patients and one patient underwent emergency angiography. No patients died of SRH.

Conclusions: SRH is a rare but potentially serious complication of URSL. Severe hydronephrosis and a thin renal cortex preoperatively and prolonged operative duration are strong predisposing factors for SRH. Laparoscopic ureterolithotomy should be considered as an alternative surgery for patients with severe ureteral tortuosity. SRH is treated based on patients' clinical manifestations. Most patients can be managed with conservative treatment or percutaneous drainage alone.