Effect of retropneumoperitoneum on cerebral and renal oxygen saturation during retroperitoneal robotic-assisted laparoscopic pyeloplasty (R-RALP) in a pediatric population: preliminary results of a prospective observational study using a dedicated anesthetic protocol and Near-InfraRed Spectroscopy.

BACKGROUND: Retroperitoneal robotic-assisted laparoscopic pyeloplasty (R-RALP) for ureteropelvic junction obstruction (UPJO) has gained growing acceptance among pediatric urologists, and is increasingly performed as day-case surgery, involving smaller children and infants. However, retroperitoneal CO2 insufflation may cause hemodynamic derangements, respiratory changes, and hypercapnia, whose consequences are poorly investigated. We, therefore, decided to prospectively study its effect on regional tissue perfusion and oxygenation in a cohort of pediatric patients undergoing R-RALP, using a dedicated anesthetic protocol and cerebral and renal Near InfraRed Spectroscopy (NIRS).

MATERIAL AND METHODS: Between January 2021 and September 2022, a cohort of 21 consecutive children [12 males (9 females), mean age of 7.1 ± 3.8 years and mean body weight of 25.7 ± 12.3 kg] underwent their first elective pyeloplasty for UPJO by R-RALP. The surgical procedure followed a previously described standardized technique and a dedicated anesthetic protocol. In conjunction with the minimal expected standard monitoring, cerebral and renal NIRS were added. Standard monitoring parameters and NIRS values were recorded at preset points throughout the procedures.

RESULTS: Standard monitoring and NIRS measurements during R-RALP were not adversely affected by CO2 insufflation, pending a significant increase in respiratory rate, aimed to avoid hypercapnia, while keeping the ventilation pressure within the safety range, preventing lung injury.

CONCLUSIONS: R-RALP, using a constant retroperitoneal CO2 insufflation pressure of 12 mmHg with a 5 L.min-1 flow, does not adversely affect respiratory and hemodynamics parameters, pending the implementation of a specifically designed anesthetic protocol aimed to prevent hypercapnia, the most threatening effect of retroperitoneal CO2 insufflation.

CLINICAL TRIAL REGISTRATION NUMBER: NCT03274050.