An Exploratory Predictive Study on the Intraoperative Change of Surgical Methods in Transurethral Ureteroscopy for Ureteral Calculi
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 入组人数
- 2,200
- 主要终点
- Intraoperative Conversion of Surgical Approach
研究概览
简要总结
This international multicenter retrospective cohort study aims to externally validate the URSL Predictive Angle, a novel CT-derived morphometric parameter, as an imaging biomarker for predicting intraoperative conversion risk during transurethral ureteroscopic lithotripsy (URSL) for ureteral calculi.
Intraoperative conversion is defined as the unanticipated abandonment of the planned endoscopic approach due to unfavorable ureteral anatomy or stone impaction, necessitating recourse to open ureterolithotomy, laparoscopic ureterolithotomy, or ureteral stent placement with planned staged secondary intervention. Such conversions are associated with protracted operative duration, heightened anesthetic exposure, and increased physical, psychological, and financial burdens on patients.
The URSL Predictive Angle is a geometric parameter derived from preoperative coronal CT reformations that quantifies the degree of local ureteral angulation induced by an impacted calculus. Preliminary single-center data demonstrated robust predictive fidelity of this metric with an area under the ROC curve of 0.861 and an optimal discriminatory threshold of 131.8° yielding a sensitivity of 82% and a specificity of 88%.
This study will enroll eligible patients from multiple domestic and international tertiary care hospitals who underwent URSL for ureteral calculi between January 1, 2018, and December 31, 2025. The primary outcome is intraoperative conversion of surgical approach. The predictive performance of the URSL angle will be evaluated using ROC curve analysis with AUC calculation. Propensity score matching and multivariable logistic regression will be employed to address potential confounding.
This study is registered as a patient registry with a cohort model. Data collection is retrospective, involving abstraction from electronic medical records, operative logs, and PACS. A waiver of informed consent has been requested based on the retrospective design, minimal risk determination, stringent anonymization procedures, and impracticability of obtaining individual consent.
详细描述
This international multicenter retrospective cohort study aims to externally validate the URSL Predictive Angle, a novel CT-derived morphometric parameter, for predicting intraoperative conversion risk during transurethral ureteroscopic lithotripsy (URSL) for ureteral calculi.
BACKGROUND
Transurethral ureteroscopic lithotripsy is the first-line minimally invasive treatment for ureteral calculi. However, in a subset of patients, intraoperative stone impaction, severe ureteral tortuosity, or anatomic variants may prevent successful ureteroscope advancement. In such cases, the surgeon must abandon the planned endoscopic approach and convert to open ureterolithotomy, laparoscopic ureterolithotomy, or temporizing stent placement with staged intervention. These unanticipated conversions increase operative duration, anesthetic exposure, and patient burden.
Currently, preoperative conversion risk assessment relies largely on subjective surgeon judgment, with no objective, reproducible predictive tool available. Existing literature focuses on stone attributes (size, location, Hounsfield units) or ureteral wall thickness, but ureteral geometry remains unexplored.
PRELIMINARY DATA
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Retrospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age > 18 years at the time of surgery, without restriction based on sex, ethnicity, or occupation.
- •Preoperative imaging confirmation of unilateral, solitary, or unilateral multiple ureteral calculi. In cases of ipsilateral multiple stones, the calculus deemed primarily responsible for obstruction or designated as the principal surgical target shall serve as the index stone.
- •Planned and attempted transurethral ureteroscopic lithotripsy as the initial treatment modality.
- •Availability of preoperative thin-slice (section thickness ≤ 1.25 mm) computed tomography urography or non-contrast CT of the urinary tract in native Digital Imaging and Communications in Medicine (DICOM) format, of sufficient diagnostic quality to permit multiplanar reconstruction and precise morphometric analysis. Image data must be complete and free from substantial motion or beam-hardening artifact that would preclude accurate delineation of ureteral anatomy.
排除标准
- •1.Absence of preoperative CT imaging performed at the participating institution; missing, corrupted, or irretrievable DICOM data; or suboptimal image quality that precludes reliable ureteral segmentation and measurement.
- •2.Incomplete inpatient medical records lacking essential demographic or baseline clinical data; operative notes containing insufficient procedural detail to definitively ascertain whether intraoperative conversion occurred or to adjudicate the specific etiology thereof.
- •3.Prior ipsilateral percutaneous nephrostomy tube placement or ureteral stent indwelling for any indication before the index URSL procedure.
- •4.Calculi situated at anatomically distinct locations, specifically the ureteropelvic junction or the ureteral orifice.
- •5.Antecedent ipsilateral ureteral surgery (e.g., ureteral reimplantation, prior ureteroscopic lithotripsy) or history of urinary diversion (e.g., ileal conduit). Such patients are excluded because surgical alteration of native ureteral anatomy would confound the morphometric assumptions underlying URSL angle determination.
研究组 & 干预措施
Success Group
Patients who successfully underwent transurethral ureteroscopic lithotripsy without intraoperative conversion, defined as successful endoscope advancement to the target calculus, completion of lithotripsy and stone extraction, and no deviation from the planned surgical approach due to ureteral conditions or stone characteristics.
Conversion Group
Patients who experienced intraoperative conversion from transurethral ureteroscopic lithotripsy to an alternative surgical modality due to technical impediments attributable to unfavorable ureteral anatomy or stone impaction. Alternative modalities include open ureterolithotomy, laparoscopic ureterolithotomy, or ureteral stent placement with planned staged secondary intervention.
结局指标
主要结局
Intraoperative Conversion of Surgical Approach
时间窗: At the time of surgery, as documented in the operative record
Unanticipated abandonment of the planned transurethral ureteroscopic lithotripsy procedure due to technical impediments directly attributable to unfavorable ureteral anatomy or calculus impaction, necessitating intraoperative recourse to an alternative surgical modality. Alternative modalities include open ureterolithotomy, laparoscopic ureterolithotomy, or ureteral stent placement with planned staged secondary intervention. Conversions due to equipment malfunction, hemodynamic instability, or other non-anatomic etiologies are excluded. Outcome will be ascertained by retrospective review of operative records.
次要结局
未报告次要终点