Comparison of dynamic thiol/disulfide homeostasis in percutaneous nephrolithotomy and retrograde intrarenal surgery

Systemic oxidative stress refers to a condition that arises when the production of oxygen-derived free radicals exceeds the capacity of the body's antioxidant defense mechanisms to neutralize them. In recent years, dynamic thiol/disulfide homeostasis has emerged as a sensitive and reversible indicator of oxidative stress. Under oxidative conditions, free thiol groups are converted into disulfide bonds and subsequently reduced back to thiols, reflecting the organism's redox status and antioxidant capacity. Therefore, thiol/disulfide homeostasis parameters are utilized to objectively assess the biochemical effects of surgical stress. In this study, we aimed to compare the effects of two commonly used procedures - percutaneous nephrolithotomy (PNL) and retrograde intrarenal surgery (RIRS) - on systemic oxidative stress.

Eighty patients with renal stones measuring 2-3 cm were prospectively assigned to undergo either PCNL (n=40) or RIRS (n=40). Serum levels of total thiol, free thiol (SH), and disulfide (SS) were measured before and after surgery, and the ratios, SS/total thiol, SS/SH and SH/total thiol were calculated.

No significant differences were observed between the groups in demographic characteristics, stone-free rates, procedure times, or complication frequencies (p>0.05). Postoperatively, both total thiol and SH levels decreased significantly, while SS levels and related ratios increased significantly (p<0.05). However, the magnitude of these changes did not differ between PCNL and RIRS (p>0.05). Patients who experienced complications had significantly lower postoperative thiol levels than those without complications (p<0.05).

Despite their different levels of invasiveness, both techniques elicited comparable systemic oxidative stress responses. These findings suggest that dynamic thiol/disulfide homeostasis parameters may serve as reliable biomarkers for monitoring surgery-induced oxidative stress and predicting postoperative complications.