Laparoscopic pyeloplasty and isthmusectomy in horseshoe kidney with ureteropelvic junction obstruction: a case report and review of the literature

BACKGROUND: Ureteropelvic junction (UPJ) obstruction is commonly observed in patients with horseshoe kidneys due to congenital anatomical anomalies, presenting unique challenges in both diagnosis and surgical management. The role of isthmusectomy in laparoscopic reconstructive surgery for this condition remains a topic of ongoing debate. This report outlines our initial experience with a minimally invasive approach to managing UPJ obstruction in a horseshoe kidney patient, utilizing Anderson-Hynes dismembered pyeloplasty combined with isthmusectomy. CASE PRESENTATION: A 28-year-old Vietnamese male was admitted with recurrent right flank pain and fever. A known diagnosis of congenital horseshoe kidney was noted. Contrast-enhanced computed tomography revealed a horseshoe kidney with grade III right-sided hydronephrosis and an atrophic left kidney. Diuretic renal scintigraphy with DTPA revealed a decline in glomerular filtration rate (GFR) in both kidneys, with values of 7.97 mL/min (15.8%) on the left side and 42.5 mL/min (84.2%) on the right side, accompanied by significant right-sided obstruction evidenced by a delayed half-time clearance exceeding 30 min. A transperitoneal laparoscopic approach was selected for surgical reconstruction. Intraoperatively, a lower pole vessel was found crossing anterior to the right ureteropelvic junction (UPJ), causing compression and obstruction. In addition, the renal isthmus was located posterior to the ureter, resulting in kinking. Isthmusectomy was performed using an endoscopic stapler to relieve the anatomical distortion. The right ureter was transected, relocated anterior to the crossing vessel, and reconstructed using the Anderson-Hynes dismembered pyeloplasty technique over a pre-inserted double-J stent. The procedure lasted 270 min with an estimated blood loss of 50 mL. The drain was removed on postoperative day 3, and the patient was discharged on day 5 without complications. At 3-month follow-up, the patient remained asymptomatic. Postoperative imaging demonstrated preserved renal function and significant improvement in right-sided urinary drainage, with reduced hydronephrosis and improved excretory function on follow-up DTPA renal scintigraphy. CONCLUSIONS: Transperitoneal laparoscopic Anderson-Hynes pyeloplasty combined with isthmusectomy appears to be a feasible and safe option for managing ureteropelvic junction obstruction in patients with horseshoe kidney, particularly in cases involving vascular compression or isthmus-related obstruction, when performed by experienced surgeons.