Objective: Supine Percutaneous Nephrolithotomy (PCNL) is a minimally invasive method that is frequently used in the treatment of kidney stones larger than 2 cm. It has been suggested that one of the risk factors that may affect the success of PCNL is the stone to skin distance (SSD). We aimed to investigate the effect of SSD on surgical outcomes in patients who underwent supine PCNL surgery.

Material and Method: One hundred and thirteen patients who underwent PCNL operation in the Galdakao modified supine Valvidia position between January 2017 and October 2021 were included in this study. Patients’ demographic information, stone characteristics, SSD, operation time, fluoroscopy time, complications and hospital stay data were collected retrospectively from the hospital database. The patients were divided into 2 groups according to the median skin to stone distance (11.80 cm (min-max: 8.20-13.10)). Patients with SSD ≤11.80 cm formed Group 1 (n = 64) and patients with SSD>11.80 cm formed Group 2 (n =49).

Results: The mean age of 113 patients included in the study was 45.17±15.2 years. BMI in Group-1 was significantly lower than Group-2 (28.37; 29.89, p ˂0.0001). It was found to be significantly shorter in SSD than in Group-1 (9.77 mm; 12.48 mm, p ˂0.0001). Although stone-free rates were high in Group-1, this was not statistically significant (84.3%; 79.6%, p =0.663). There was no significant difference between the groups in secondary interventions (p >0.05).

Conclusion: According to our data, SSD has no effect on success rate, complications, hospitalization time, fluoroscopy time and reoperation rates in supine PCNL surgeries.