Does Severe Obesity Effect Early Postoperative Recovery and Surgical Outcomes in Patients Undergoing Percutaneous Nephrolithotomy Under Spinal Anesthesia?

Objective: The primary aim of this study is to evaluate if severe obesity has any deleterious effect on the early postoperative course in patients undergoing percutaneous nephrolithotomy (PNL) under spinal anesthesia, and the secondary aim is to determine whether severe obesity changes surgical results. Material and Method: The study included 100 patients who underwent a PNL operation for kidney stones of ≥2cm in our clinic. Accordingly, those with BMI <35 kg/m2 formed the first while the severely obese BMI ≥35 kg/m2 formed the second group. Age, gender, stone burden, pre/postoperative hemoglobin levels, number and regions of access, duration of surgery, perioperative complications and Visual Analogue Scale score at 24h, PACU admission/ discharge Aldrete scores, and PACU length of stay were recorded. Results: The VAS score was 5.0±1.3 in group 1 while it was 5.3±1.8 in group 2 (p=0.32). The length of the hospital stay was 3.3±1.3 days in patients with BMI <35 kg/m2 and 3.0±1.0 in patients with BMI ≥35 kg/m2 (p=0.36). A 98% stone-free rate was found in the severely obese group and 96% in the normal BMI group, and there was no significant difference between the groups (p=0.672). There was a statistically significant difference in terms of PACU discharge Aldrete scores between groups (9.9±0.3 vs. 9.6±0.4 in groups 1 and 2, respectively) (p=0.03). Finally, the time interval in PACU was 39.0±7.5 mins in group 1 while it was 58.8±14.0 mins in group 2 (p<0.0001). Conclusions: Severe obesity does not alter surgical outcomes in patients undergoing PNL under spinal anesthesia, and in our opinion, spinal anesthesia in PNL is a safe and effective anesthesia modality for renal stone(s) in obese and morbidly obese patients.