[Endoscopic combined ultrasound-guided access vs. ultrasound-guided access in endoscopic combined intrarenal surgery]

To compare the outcomes of endoscopic combined ultrasound-guided access (EUGA) with the conventional ultrasound-guided access (UGA) to achieve percutaneous renal access in endoscopic combined intrarenal surgery (ECIRS).

A retrospective review of 53 patients undergoing ECIRS to treat upper urinary tract calculi between January 2017 and October 2019 was con-ducted. All of the cases were of complex upper urinary tract stones larger than 2 cm in diameter. The com-plex stone situations, such as multiple renal calyces calculi or staghorn calculi necessitated ECIRS. Under general anesthesia, the patients were placed in the galdakao-modified supine valdivia (GMSV) position, thus allowing both antegrade and retrograde accesss. The patients were divided to UGA and EUGA groups according to the protocol of achieving percutaneous renal access. In 28 cases, endoscopic combined ultrasound-guided accesss were obtained. Puncture and dilation were performed under direct flexible ureteroscopic visualization, while percutaneous renal access of 25 cases were performed with the conventional technique employing ultrasound guidance. Demographic and perioperative information, such as stone burden, presence of hydronephrosis and number of calyces involved was compared. Primary outcomes included total operative time, renal access time, repeat puncture, hemoglobin level, perioperative complications, and stone-free rate.

No major intra-operative complication was recorded in all the 53 ECRIS. No significant difference was observed between the groups in age and gender. There was no significant difference in body mass index[BMI (29.21±3.14) kg/m² vs.(28.53±2.56) kg/m²], stone burden (37.68±6.89) mm vs. (35.53±6.52) mm, number of calyces involved 2.72±0.68 vs. 2.86±0.71, presence of hydronephrosis (56.0% vs. 46.4%), total operative time (93.0±12.2) min vs. (96.8±14.2) min, hemoglobin level reduction (6.56±2.16) g/L vs. 97.54±2.64) g/L, stone-free rate (92.0% vs. 92.8%), hospital stay (5.52±0.59) d vs. (5.64±0.62) d, perioperative complication rate (8.0% vs. 7.2%). Two patients in EUGA group experienced perioperative complications (one urinary tract infection and one hematuria) while two patients in UGA group experienced perioperative urinary tract infection. None in both groups received blood transfusion. The patients undergoing EUGA had shorter renal access time [(4.0±0.7) min vs. (6.8±2.6) min, P < 0.01] and less repeat puncture (0 vs. 4 cases, P < 0.05).

EUGA is an optimal technique to establish percutaneous renal access in ECIRS, which minimizes access time and repeated procedures.