What should the optimal access site be for percutaneous treatment of anterior lower pole calyx stones?

Abstract

Compared to other stone groups, anterior calyx stones are more challenging for endourologists to treat. This study aims to evaluate the differences between our latest technique and conventional techniques for treating anterior calyx stones in the lower pole. Patients with isolated anterior lower pole calyx or complex lower pole stones with anterior calyx branching were included in the study. The first group included lower pole access, while the second group included percutaneous treatment through the middle or upper pole. In the first group, the posterior calyx or direct anterior calyx approach was utilised depending on whether the stone was isolated calyx, complex structure or calyx anatomy, while in the second group, percutaneous nephrolithotomy was performed through the middle or upper pole posterior calyx access. There were 37 patients in Group 1 and 25 patients in Group 2. Both groups were similar regarding patient age, sex, stone burden, and stone localisation (p > 0.05). When comparing operative and post-operative data between groups, it was found that the stone clearance rate, number of accesses, and haematocrit decrease were statistically superior in the second group (p: 0.003, p: 0.002, p: 0.018), with no significant difference in mean operative time, length of hospital stay, fluoroscopy time and pain score (p > 0.05). Percutaneous surgery utilising an access from a calyx distal to the stone may offer better clearance and lower morbidity rates for lower pole stones involving the anterior calyx.