Current guidelines recommend repeat computed tomography (CT) imaging in high-grade blunt renal injury within 48–96 h, yet diagnostic value and clinical significance remain controversial. The aim of this work was to determine the possible gain of CT re-imaging in uncomplicated patients with blunt renal trauma at 48 h after injury, presenting one of the largest case series. A retrospective database of patients admitted to our centre with isolated blunt renal trauma due to sporting injuries was analysed for a period of 20 years (2000–2020). We included only patients who underwent repeat imaging at 48 h after trauma irrespective of AAST renal injury grading (grade 1–5) and initial management. The primary outcome was intervention rates after CT imaging at 48 h in uncomplicated patients versus CT scan at the time of clinical symptoms. A total of 280 patients (mean age: 37.8 years; 244 (87.1%) male) with repeat CT after 48 h were included. 150 (53.6%) patients were classified as low-grade (grade 1–3) and 130 (46.4%) as high-grade (grade 4–5) trauma. Immediate intervention at trauma was necessary in 59 (21.1%) patients with high-grade injuries: minimally invasive therapy in 48 (81.4%) and open surgery in 11 (18.6%) patients, respectively. In only 16 (5.7%) cases, intervention was performed based on CT re-imaging at 48 h (low-grade vs. high-grade: 3.3% vs. 8.5%; p = 0.075). On the contrary, intervention rate due to clinical symptoms was 12.5% (n = 35). Onset of clinical progress was on average (range) 5.3 (1–17) days post trauma. High-grade trauma (odds ratio [OR]grade 4 vs. grade 3, 14.62; p < 0.001; ORgrade 5 vs. grade 3, 22.88, p = 0.004) and intervention performed at the day of trauma (OR 3.22; p = 0.014) were powerful predictors of occurrence of clinical progress. Our data suggest that routine CT imaging 48 h post trauma can be safely omitted for patients with low- and high-grade blunt renal injury as long as they remain clinically stable. Patients with high-grade renal injury have the highest risk for clinical progress; thus, close surveillance should be considered especially in this group.

中文翻译：

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我们是否需要在简单的钝性肾损伤中重复 CT 成像？高容量泌尿外科创伤中心的经验

目前的指南建议在 48-96 小时内对重度钝性肾损伤进行重复计算机断层扫描 (CT) 成像，但其诊断价值和临床意义仍存在争议。这项工作的目的是确定在损伤后 48 小时对单纯性钝性肾损伤患者进行 CT 重新成像的可能增益，这是最大的病例系列之一。对我们中心因运动损伤而收治的孤立性钝性肾损伤患者的回顾性数据库进行了为期 20 年（2000-2020 年）的分析。我们仅纳入在创伤后 48 小时接受重复成像的患者，无论 AAST 肾损伤分级（1-5 级）和初始管理如何。主要结果是无并发症患者在 48 小时 CT 成像后的干预率与临床症状时的 CT 扫描。共纳入 48 小时后复查 CT 的 280 名患者（平均年龄：37.8 岁；244 名（87.1%）男性）。150 名 (53.6%) 患者被归类为低级别 (1-3 级) 和 130 (46.4%) 名患者被归类为高级别 (4-5 级) 创伤。59 名 (21.1%) 重度损伤患者需要立即进行创伤干预：分别有 48 名 (81.4%) 患者接受微创治疗，11 名 (18.6%) 患者接受开放手术。仅在 16 例 (5.7%) 病例中，基于 48 小时 CT 重新成像进行了干预（低级别与高级别：3.3% 与 8.5%；p = 0.075）。相反，因临床症状引起的干预率为 12.5%（n = 35）。临床进展的开始时间平均（范围）在创伤后 5.3（1-17）天。高级别创伤（优势比 [OR] 4 级与 3 级，14.62；p < 0.001；OR 5 级与 3 级，22.88，p = 0。004）和在创伤当天进行的干预（OR 3.22；p = 0.014）是临床进展发生的有力预测因素。我们的数据表明，只要临床稳定，低度和高度钝性肾损伤患者可以安全地省略创伤后 48 小时的常规 CT 成像。重度肾损伤患者的临床进展风险最高；因此，特别是在这个群体中，应考虑密切监视。