Flexible Ureteroscopy With a Flexible and Navigable Suction Ureteral Access Sheath Versus Mini-Percutaneous Nephrolithotomy for 1-2 cm Lower Pole Renal Stones: an International, Multicenter, Randomized Non-Inferiority Trial (FLAME Trial)
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 640
- 试验地点
- 1
- 主要终点
- Immediate Stone-Free Rate (SFR)
研究概览
简要总结
This study, known as the FLAME Trial (Flexible ureteroscopy for Lower pole stones And Mini-pErcutaneous nephrolithotomy), is an international, multicenter, randomized, non-inferiority trial. It aims to compare the effectiveness and safety of flexible ureteroscopy using a flexible and navigable suction ureteral access sheath (FANS) versus mini-percutaneous nephrolithotomy (mini-PCNL) in the treatment of 1-2 cm lower pole kidney stones.
A total of 640 eligible adult patients will be enrolled across 20 high-volume urology centers in China, Russia, Turkey, and India. Participants will be randomly assigned to undergo either FANS-assisted flexible ureteroscopy or mini-PCNL. The primary outcome is the immediate stone-free rate (SFR) assessed by non-contrast CT within 72 hours after surgery. Secondary outcomes include SFR at 1 month, operative time, pain score, length of hospital stay, complication rates, and changes in health-related quality of life.
The goal of this trial is to determine whether the less invasive FANS-assisted approach is non-inferior to mini-PCNL in terms of efficacy, while potentially offering advantages in postoperative recovery and safety.
详细描述
The FLAME Trial (Flexible ureteroscopy for Lower pole stones And Mini-pErcutaneous nephrolithotomy) is an international, multicenter, prospective, randomized, controlled, non-inferiority study that aims to evaluate the safety and efficacy of flexible ureteroscopy assisted by a Flexible and Navigable Suction Ureteral Access Sheath (FANS) compared with mini-percutaneous nephrolithotomy (mini-PCNL) in the treatment of 1-2 cm lower pole renal stones.
This trial will enroll 640 patients from 20 urology centers with substantial experience in endoscopic stone surgery, including hospitals in China, Russia, Turkey, and India. Eligible participants will be randomly assigned in a 1:1 ratio to either the FANS-assisted flexible ureteroscopy group or the mini-PCNL group. All patients will undergo preoperative imaging, intraoperative standardization, and postoperative follow-up according to the study protocol.
The primary endpoint is the stone-free rate (SFR) within 72 hours postoperatively, evaluated by non-contrast-enhanced computed tomography (NCCT). Secondary endpoints include SFR at 1 month, operative time, length of hospital stay, postoperative pain (measured by VAS score), complication rates (graded by Clavien-Dindo classification), changes in renal function, and health-related quality of life (HRQoL).
The FANS, developed to improve irrigation control and active stone fragment suction during flexible ureteroscopy, may provide better visualization, reduce intrarenal pressure, and shorten operative time. By directly comparing FANS-assisted fURS with mini-PCNL, the trial seeks to determine whether a less invasive method can achieve comparable outcomes in terms of stone clearance and complication rates.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Double (Investigator, Outcomes Assessor)
盲法说明
Blinding of participants and surgeons is not feasible due to the obvious procedural differences between flexible ureteroscopy with FANS and mini-percutaneous nephrolithotomy. However, radiologists assessing postoperative CT scans will be blinded to treatment allocation. Clinical follow-up assessments will be performed by independent investigators who did not participate in the surgeries. Statistical analysis will also be conducted in a blinded manner, with group assignments concealed from the analyst until data interpretation is complete.
入排标准
- 年龄范围
- 18 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Adults aged 18-75 years;
- •American Society of Anesthesiology (ASA) score 1-3;
- •Lower pole renal stones-single or multiple-with a maximal diameter of 1-2 cm confirmed by CT;
- •Ability to provide written informed consent and adhere to trial requirements.
排除标准
- •Significant urinary tract anatomical anomalies (e.g. horseshoe kidney, ileal conduit);
- •Stones located within a calyceal diverticulum;
- •History of open nephrolithotomy or ureterolithomy (due to resultant intrarenal anatomical distortion);
- •Absolute contraindications to either FANS-f-URS or mini-PCNL, including:
- •Uncorrectable coagulopathy;
- •Active, uncontrolled urinary tract infection;
- •Severe cardiopulmonary disease precluding safe general anesthesia (e.g. decompensated heart failure, refractory COPD);
- •Pregnancy;
- •Inability to tolerate lithotomy or prone positioning;
- •Inability to understand or complete trial documentation.
研究组 & 干预措施
FANS-fURS Group
Patients assigned to this group will undergo flexible ureteroscopy with FANS (Flexible endoscopy-Assisted Negative-pressure Suction Sheath). The FANS facilitates direct stone visualization, fragmentation, suction, and removal under controlled pressure conditions.
干预措施: Flexible ureteroscopy with FANS (Procedure)
mini-PCNL Group
Patients in this group will receive mini-percutaneous nephrolithotomy (mini-PCNL) via less than 20 Fr percutaneous tracts.
干预措施: Mini-percutaneous nephrolithotomy (mini-PCNL) (Procedure)
结局指标
主要结局
Immediate Stone-Free Rate (SFR)
时间窗: 72 hours after surgery
Stone-free status will be evaluated using non-contrast-enhanced computed tomography (NCCT) performed within 72 hours after surgery. Stone-free is defined as the absence of residual stone fragments or presence of clinically insignificant fragments ≤2 mm.
次要结局
- Final Stone-Free Rate (SFR) at 1 Month(1 month after surgery)
- Postoperative Pain Level(Within 24 hours after surgery.)
- Operative Time(Intraoperative)
- Length of Hospital Stay(From the day of surgery until the day of discharge, assessed up to 30 days postoperatively.)
- Complication Rate Within 1 Month(1 month after surgery.)
- Change in Quality of Life Score(Baseline and 1 month after surgery.)
研究者
Guohua Zeng
Vice-president
The First Affiliated Hospital of Guangzhou Medical University