Dartmouth Hitchcock Medical Center, Section of Urology, Lebanon, NH.
Dartmouth Hitchcock Medical Center, Section of Urology, Lebanon, NH.
Urology. 2014 Jan;83(1):45-9. doi: 10.1016/j.urology.2013.09.008. Epub 2013 Nov 6.
To validate the Guy's stone score (GSS) using preoperative computed tomography (CT) and to assess its inter-rater concordance and association with rigorous definitions of stone clearance.
The preoperative CT scans of 166 consecutive percutaneous nephrolithotomy (PCNL) patients treated by a single surgeon were independently reviewed by 2 urology residents and graded according to GSS. Concordance was calculated using Cohen's kappa score. Residual fragments (RFs) were evaluated on CT or plain radiography on postoperative day 1. GSS was correlated with 3 different outcomes; RFs <4 mm, RFs <2 mm, or no RFs.
Higher GSS was associated with decreased stone clearance by any metric on a CT scan: RFs <4 mm (P = .03), RFs <2 mm (P = .02), or no RFs (P = .02). On plain radiography, higher GSS was only associated with lower likelihood of no RFs (P <.005). Inter-rater concordance was good (κ = 0.72), with 78% of cases categorized the same by both raters. Twelve of 36 cases (33%) of disagreement were between categories II and III and 20 of 36 cases (56%) pertained to unclear definitions of "partial staghorn stone" and "abnormal anatomy."
The GSS is a straightforward grading system of the complexity of renal stones. When applied to preoperative CT scans, it offers good inter-rater concordance and is associated with rigorous endpoints of stone clearance. The inter-rater concordance could be further improved by explicit definitions of abnormal anatomy, partial vs complete staghorn stones, and the size of a calculus that constitutes a separate stone.
利用术前计算机断层扫描（CT）验证 Guy 结石评分（GSS），并评估其评分者间一致性及其与严格结石清除定义的关系。
对单名外科医生治疗的 166 例经皮肾镜取石术（PCNL）患者的术前 CT 扫描进行独立回顾，由 2 名泌尿科住院医师根据 GSS 进行分级。采用 Cohen's kappa 评分计算一致性。术后第 1 天，通过 CT 或普通 X 线片评估残余碎片（RFs）。GSS 与 3 种不同的结果相关：RFs＜4mm、RFs＜2mm 或无 RFs。
较高的 GSS 与任何 CT 扫描下的结石清除率降低相关：RFs＜4mm（P=0.03）、RFs＜2mm（P=0.02）或无 RFs（P=0.02）。在普通 X 线片上，较高的 GSS 仅与无 RFs 的可能性较低相关（P＜0.005）。评分者间一致性良好（κ=0.72），78%的病例由两名评分者分类相同。36 例中有 12 例（33%）的不一致性在 II 类和 III 类之间，36 例中有 20 例（56%）涉及“部分鹿角形结石”和“异常解剖”定义不明确。
GSS 是一种用于评估肾结石复杂性的简单分级系统。当应用于术前 CT 扫描时，它提供了良好的评分者间一致性，并与结石清除的严格终点相关。通过对异常解剖、部分与完全鹿角形结石以及构成独立结石的结石大小的明确定义，可以进一步提高评分者间的一致性。
