Outcomes of ureteroscopy and internal ureteral stent for pregnancy with urolithiasis: a systematic review and meta-analysis

Objectives To investigate the outcomes of internal ureteral stent versus ureteroscopy (URS) treatments for pregnant women with urolithiasis. Design This is a systematic review and meta-analysis of observational studies that investigated the outcomes of internal ureteral stent and ureteroscopy for pregnancy with urolithiasis. This systematic review have been registered on the PROSPERO website (www.york.ac.uk/inst/crd, registration number: CRD42020195607). Data Sources Relevant studies published from January 1980 to April 2020 were identified through a systematic literature search in MEDLINE, EMBASE, Web of Science and the Cochrane Library. Data extraction and synthesis All pregnant women in their all pregnancy stages who were underwent double-J (D-J) stent insertion only or URS operation for lithotripsy/stone extraction/exploration were considered. The number of related participants in study more than 10 were included. Fertility outcome and complications of intervention were extracted as main outcomes, while other data such as operation success rate, stone free rate (SFR), patient characteristics, anaesthetic method, ureteral stone characteristics, detail of interventions were obtained as well. Complications were stratified according to Clavien-Dindo criteria. Two authors independently extracted data and assessed the quality of included studies. Study-specific prevalence rates were pooled using a random-effects model. We applied the Newcastle-Ottawa Scale quality assessment to evaluate the quality of the selected studies. Results A total of 25 studies were identified with 131 cases undergoing serial stenting and 789 cases undergoing URS operation. The age range was from 16 to 41, and urolithiasis occurred in the second trimester most. Ultrasound was the most commonly used diagnostic method. The most common site of calculi was distal ureter. The average stone size was between 6-17mm. There were 6 studies investigating D-J stent insertion only, while 23 studies involving URS operation. The most commonly used anesthesia for internal ureteral stent therapy was local anesthesia, and for URS treatments, general anesthesia and spinal anesthesia were widely used. The pooled operation success rate was 97% for D-J stent insertion, and 99% for URS. Serial D-J stenting was an effective methods for treating ureter obstruction and only a few patients passed stone spontaneously. Different common lithotripters were used in URS operations and the pooled SFR was about 91%. For internal ureteral stent therapy; the rate of normal fertility outcome was 99%, but the pooled incidence of complications was about 45%. For the URS treatment group, the rate of normal fertility outcome was 99% as well, and the pooled incidence of complications was about 1%. However, the pooled premature and abortion incidence rate of two group were the same as less than 1%, and the same as this in serious complication incidence rate. Conclusions Both ureteroscopy operation and internal ureteral stent were usually used for handing pregnancy with urolithiasis. Two treatments had less side effective on fertility outcome, but internal ureteral stent may cause more complications. Evidence suggests that URS therapy may have a greater advantage for pregnancy with urolithiasis when the conditions permit. As it is proved safe and effective, internal ureteral stent could be considered at emergency condition or preoperative preparations was lack.