使用可彎曲輸尿管鞘與銩光纖雷射於雙側馬蹄腎結石之病例報告

張君愷、徐振益、歐弦哲、阮雍順、葉信志、李香瑩、闕光瞬、溫聖辰、吳怡萱

高雄醫學大學附設中和紀念醫院 泌尿部

Bilateral retrograde intrarenal surgery using flexible and navigable suction ureteral access sheath and Thulium fiber laser in a bilateral horseshoe kidney stone: A case report

Chun-Kai Chang, Cheng-Yi Hsu, Hsien-Che Ou, Yung-Shun Juan, Hsin-Chih Yeh, Hsiang-Ying Lee, Kuang-shun Chueh, Sheng-Chen Wen, Yi-Hsuan Wu

Department of Urology, Kaohsiung Medical University Chung-Ho Memorial Hospital, Kaohsiung, Taiwan

Introduction:

Horseshoe kidney is the most common renal fusion anomaly, occurring in approximately 1 in 400–600 live births. It is frequently associated with impaired urinary drainage, anomalous ureteral insertion, and malrotation, all of which predispose to urinary stasis and nephrolithiasis. The altered anatomy makes endourological procedures, particularly flexible ureteroscopy (fURS) and retrograde intrarenal surgery (RIRS), technically challenging due to difficulties in accessing the renal pelvis and calyces.

In recent years, the introduction of flexible and navigable suction access sheath and thulium fiber laser (TFL) technology has improved visualization, reduced intrarenal pressure, and enhanced stone clearance. Here, we present a case of bilateral renal stones in a patient with horseshoe kidney successfully treated with staged RIRS using a flexible and navigable suction access sheath (FANS) and thulium fiber laser (TFL).

Case Report:

A 49-year-old male with a known history of horseshoe kidney and urolithiasis presented to another hospital with right flank pain and gross hematuria. Computed tomography (CT) of the abdomen revealed a 1.35 x 0.98cm right ureteropelvic junction (UPJ) stone with stone density of 1138.9 ± 113.9 Hounsfield unit (HU) with obstructive uropathy related to the horseshoe kidney anomaly and an additional 1.04 x 0.68cm left renal stone with stone density of 971.3 ± 215.1 Hounsfield unit (HU). For personal reasons, the patient later sought further management at our outpatient department.

Initially, bilateral RIRS was planned. However, during operation, bilateral ureteral strictures were identified, making primary ureteroscopic access difficult. Therefore, double-J stents were inserted bilaterally for pre-stenting and passive ureteral dilation.

After one month, the patient underwent bilateral RIRS under general anesthesia. A flexible ureteroscope (fURS) was introduced through a 10/12 Fr. 50 cm flexible and navigable suction ureteral access sheath (FANS). Bilateral renal stones were identified and fragmented using a thulium fiber laser (TFL). Stone fragments were subsequently extracted via FANS suction. Postoperatively, the patient recovered uneventfully and discharge in the . Follow-up KUB and renal ultrasonography confirmed a stone-free status on both sides. The double-J stents were removed three weeks later.

Discussion:

Treatment of urolithiasis in horseshoe kidneys poses several challenges due to abnormal renal rotation, high ureteral insertion, and anteriorly displaced collecting systems. These factors may lead to suboptimal drainage and increase the risk of stone recurrence.

Historically, percutaneous nephrolithotomy (PCNL) was considered the preferred approach for large stones in anomalous kidneys. However, advances in flexible ureteroscopes and laser technologies have made RIRS a feasible and minimally invasive alternative for small to medium-sized stones.

In this case, we utilized the Flexible and Navigable Suction Access Sheath (FANS), which allows active suction of irrigation fluid and stone fragments, maintaining low intrarenal pressure and clear visibility throughout the procedure. This system is especially valuable in complex renal anatomies such as horseshoe kidneys, where high pressure can lead to backflow and infection risk. The thulium fiber laser, characterized by fine dusting efficiency, high ablation rate, and minimal retropulsion, further optimized stone fragmentation and reduced operative time.

A recent comparative study (Ahmed et al., 2025) demonstrated that RIRS in congenital renal anomalies, including horseshoe kidney, achieved higher stone-free rates than extracorporeal shockwave lithotripsy (SWL) (81.9% vs 56.6%) with fewer re-treatments. Our case supports these findings, showing that using of suction-assisted sheath and advanced laser systems, RIRS can be both safe and effective even in anatomically challenging kidneys.

Conclusion:

This case demonstrates that bilateral RIRS using a Flexible Navigable Suction Access Sheath (FANS) and Thulium Fiber Laser (TFL) is a feasible, safe, and effective approach for stone management in patients with horseshoe kidney. Low-pressure suction systems can significantly enhance surgical safety and improve stone clearance rates. These technologies may expand the applicability of RIRS in complex renal anatomies.