Secondary calyceal neck atresia induced by postoperative hemorrhage and hyperinflammation after FURL in a solitary functional kidney with contralateral renal atrophy: a case report.

Flexible ureteroscopic holmium laser lithotripsy (FURL) is a mainstream minimally invasive treatment for nephrolithiasis with rare late complications. We report a case of secondary calyceal neck atresia after FURL in a 71-year-old male with left renal atrophy, hypertension, and preoperative Escherichia coli urinary tract infection. Standardized anti-infective preparation was given preoperatively, with no intraoperative calyceal neck injury observed. However, severe hemorrhage and hyperinflammation occurred postoperatively, which was controlled with treatment. Three-month follow-up confirmed complete atresia of the right lower calyceal neck. This case emphasizes rigorous perioperative management and long-term surveillance in high-risk populations.