The Watertightness of the Anastomosis After Laparoscopic or Robot-Assisted Pyeloplasty: Is a Drainage Necessary?

Objective: To determine whether or not temporary drainage is necessary immediately following laparoscopic (lap) and robot-assisted (rob) pyeloplasty (PP). Patients and Methods: Of 99 patients undergoing lap PP (n=23) or rob PP (n=76) for treatment of ureteropelvic junction obstruction (UPJO), 52 had no drainage, 47 were given an easy-flow drain (EFD). The volume of leaking urine (in mL) was defined as the volume of drainage fluid (in mL)xcreatinine concentration in drainage fluid (in mol/mL)/median urine creatinine concentration (in mol/mL). An anastomosis was considered to be leaking if the volume of leaking urine exceeded 5mL/24 hours. During follow-up the PP success rate was evaluated based on clinical symptoms, intravenous urography and diuretic renography for detection of persisting obstruction. Results: Median creatinine concentration in drainage fluid was 90mol/L (range 44-6270mol/L) in a median volume of 84mL (range 5-1400mL) drained fluid in 24 hours. The median leaking urine volume was 1.18mL (range 0.07-291.34mL), a leaking anastomosis was diagnosed in 5/47 (11%) patients. In patients with EFD and without EFD, complications occurred in 15% and 8% (p=0.342), respectively, with success rates of 98% and 100% (p=0.475). Complications (Clavien I-III) occurred in 4/42 (9.5%) patients with watertight and in 3/5 (60%) patients with leaking anastomosis (p=0.019). No statistically significant differences were noted between lap PP and rob PP patients regarding complication and success rates. Conclusion: Lap PP and rob PP were primary watertight in 89% of all patients. A primary leaking anastomosis had no influence on PP outcome, but was associated with a higher risk of complications. However, neither the success rate nor the complication rate differed between drained and undrained patients. We conclude, therefore, that drainage is not necessary.