Department of Urology, Muljibhai Patel Urological Hospital, Nadiad, Gujarat, India.
J Endourol. 2012 Jan;26(1):6-14. doi: 10.1089/end.2011.0145.
Staghorn stone volume and its distribution within the collecting system, "staghorn morphometry," predicts the requirement of tract and stage for percutaneous nephrolithotomy (PCNL) monotherapy. The purpose of the study was to develop a CT urography staghorn morphometry-based prediction algorithm to predict tract(s) and stage(s) for PCNL monotherapy and classify staghorn accordingly.
A retrospective case-control design of 94 units was used. CT software calculated the total stone volume (TSV) with absolute volume and percentile volume in the pelvis, planned entry calix, favorable and unfavorable calix. Entry calix was the optimum calix chosen, keeping the relations of the ribs and adjoining viscera that could clear maximum stone volume. Unfavorable calix was defined as having an acute angle from the entry calix and infundibular width of ≤ 8 mm. A prediction model with odds ratio (OR) (95% confidence interval) was constructed on univariate and multivariate regression factors.
On univariate analysis, TSV (P=0.013), unfavorable calix stone volume (0.007), and percentile distribution of stone in pelvis (0.026), pelvis and entry calix (<0.001), and unfavorable calix (0.001) predicted tracts while total stone (<0.001), pelvic stone (0.0046), and unfavorable calix stone (<0.001) volume and percentile volume in pelvis (0.04), pelvis and entry calix (0.005) and unfavorable calix (P<0.001) predicted stage. Multivariate analysis showed that unfavorable calix stone percentile volume predicted tract (area under the curve [AUC] - 0.91) while TSV and unfavorable calix stone percentile volume (AUC - 0.846) predicted stage. The OR-based prediction model suggested a need for single tract and stage PCNL vs multiple tract and stage PCNL for TSV and unfavorable calix percentile stone volume of (<5,000 mm(3) and 5%) and (>20,000 mm(3) and 10%), respectively.
The model predicts the tract and stage for PCNL monotherapy. Staghorn morphometry differentiates staghorn into type 1 (single tract and stage); type 2 (single tract-single/multiple stage, or multiple tract-single stage), and type 3 (multiple tract and stage).
鹿角状结石体积及其在集合系统内的分布，即“鹿角状形态测量学”，可预测经皮肾镜碎石术（PCNL）单纯碎石术所需的通道和阶段。本研究的目的是开发一种基于 CT 尿路造影的鹿角状形态测量学预测算法，以预测 PCNL 单纯碎石术的通道和阶段，并对鹿角状结石进行分类。
采用 94 例病例对照的回顾性设计。CT 软件通过绝对体积和骨盆、计划进入肾盏、有利和不利肾盏的百分位数体积计算总结石体积（TSV）。进入肾盏是选择的最佳肾盏，保持肋骨和毗邻内脏的关系，以便清除最大结石体积。不利肾盏定义为与进入肾盏呈锐角，漏斗宽度≤8mm。在单变量和多变量回归因素的基础上，构建了一个比值比（OR）（95%置信区间）预测模型。
单变量分析显示，TSV（P=0.013）、不利肾盏结石体积（0.007）和骨盆内结石的百分位数分布（0.026）、骨盆和进入肾盏（<0.001）、不利肾盏（0.001）预测了通道，而总结石（<0.001）、骨盆结石（0.0046）和不利肾盏结石（<0.001）体积和骨盆内的百分位数体积（0.04）、骨盆和进入肾盏（0.005）和不利肾盏（P<0.001）预测了阶段。多变量分析显示，不利肾盏结石的百分位数体积预测了通道（曲线下面积[AUC]-0.91），而 TSV 和不利肾盏结石的百分位数体积（AUC-0.846）预测了阶段。基于 OR 的预测模型提示，对于 TSV 和不利肾盏结石的百分位数体积（<5000mm3和 5%）和（>20000mm3和 10%），需要进行单通道和单阶段或单通道-多阶段/多通道-单阶段 PCNL 治疗。
该模型预测了 PCNL 单纯碎石术的通道和阶段。鹿角状形态测量学将鹿角状结石分为 1 型（单通道和单阶段）；2 型（单通道-单/多阶段，或多通道-单阶段）和 3 型（多通道和多阶段）。
