A novel apparatus to assess intraoperative intrarenal pelvic pressure and associated clinical outcomes

Abstract

Objective

To design a simple, novel, economical apparatus which effectively provides reliable, real-time measurements of intrarenal pelvic pressure (IRPP) intraoperatively and to demonstrate clinical utility.

Patients and Surgical Procedure

Patients undergoing robotic ureteral reconstruction from 10/2020 to 7/2021 for whom intraoperative IRPP measurement was conducted were included.

Baseline opening pressure was noted with the pelvis completely drained. The kidney was intermittently drained when IRPP exceeded a certain threshold, returning the pressure to baseline. Relief of obstruction was defined as return of IRPP to physiologic value without further increases for the remainder of surgery.

Demographic, intraoperative, and post-operative variables were collected and IRPP measurements extracted. Post-operative success was defined as resolution of obstruction by clinical symptoms and imaging.

Results

Eleven patients met criteria including 4 (36.4%) men and 7 (63.6%) women. Median age and BMI was 61 years (range 14–23) and 26 kg/m² (range 17.2–42), respectively. Six patients (54.5%) had undergone prior interventions.

Ureteral reconstructive procedures included bilateral refluxing reimplants (2), unilateral reimplant with Boari flap (3), non-transecting reimplant (2), unilateral ileal ureter (1), bilateral ileal ureter (1), buccal ureteroplasty (1), and ureteroureterostomy (1). Median peak IRPP was 52 mmHg (range 27–59) and median nadir IRPP was 14 mmHg (range 1–24), with median decrease of 36 mmHg (range 26–84).

At median follow-up of 120 days, all patients had successful repairs.

Conclusions

Intraoperative measurement of IRPP can be utilized in patients with percutaneous nephrostomy tubes using readily available equipment. This measurement has the potential to ensure that ureteral obstruction is completely relieved and to prevent development of supraphysiologic IRPP during surgery.