Nefrolitotomía percutánea convencional vs. tubeless. ¿Es realmente necesaria la derivación urinaria?

Introduction: Conventional percutaneous nephrolithotomy (PNL) uses a nephrostomy derivation to improve the drainage of urine, facilitate postoperative hemostasis and allow a safe course for future additional surgical interventions. However, in recent years the PNL procedure has been modified to avoid the use of a nephrostomy catheter or any other urinary diversion. This procedure is known as tubeless. This study aims to assess the institutional experience in safety, efficiency and advantages of tubeless PNL. Materials and methods: Between August 2012 and May 2014, 51 patients were recruited in San Ignacio University Hospital and Fundadores Clinic to be treated with PNL. Forty-nine patients with kidney lithiasis less than 5 cm of diameter and greater than 2 cm with single or multiple puncture were included. They were randomised into 2 groups: group A no derivation (no nephrostomy catheter, no double J) 26 patients, group B with derivation (18 Fr Foley nephrostomy catheter) 23 patients. The evaluated outcomes were: Effectiveness verified by reviewing postoperative images and defined as a residual stone less than 5 mm of diameter, postoperative bleeding with hemoglobin measurement during the first 24 h after surgery, pain assessment with the visual analog scale, need for analgesics during the first 4 h, amount of analgesic rescues during the first 24 h of surgery. Data were analyzed using the statistical package SPSS version 20, using the nonparametric statistical test Wilcoxon Mann-Whitney 11 it was determined that the sample does not have a normal distribution, the dichotomous variables were analyzed using Chi² test. Results: Baseline characteristics of patients are comparable: The average age in the group A was 44.73 and 50.26 years in the group B (P=.186), average weight in group A and B was 75.96 kg and 71.96 kg, respectively (P=.054), the average size of the stones in group A was 28.23 mm and 29.69 mm in group B with no statistically significant difference (P=.517).There were no significant differences in effectiveness in both groups, in group A the percentage of residual lithiasis was 1.15% and 0.87% in group B (P=.713). There were no statistically significant differences in postoperative bleeding (P=.566), although pain, analgesic requirement and number of rescues needed were greater in patients who were left with a nephrostomy derivation. Discussion: Our work shows that percutaneous nephrolithotomy without urinary diversion is a safe procedure in patients in whom a complete stone removal is achieved, with bleeding comparable to conventional surgery, and additionally with the benefit of less pain and less postoperative analgesic requirement.