Data_Sheet_1_The Involvement of Renal Capsule Is Associated With Acute Kidney Injury in Patients With Acute Pancreatitis.pdf

Background: Acute pancreatitis (AP) is characterized by pancreatic/peripancreatic inflammation. Involvement of renal capsule refers to peripancreatic inflammation extending beyond the Gerota fascia and disappearance of renal rim sign (+) on CT images. However, its association with acute kidney injury (AKI), an important complication of AP, was rarely studied.
Aim: This study aimed to assess the relationship between the involvement of renal capsule and AKI in a cohort of patients with AP.
Methods: We retrospectively screened all the patients admitted for AP from January 2018 to December 2019. The involvement of renal capsule was judged by experienced radiologists according to the CT imaging. Propensity score matching (PSM) was used to control for biases in group sizes and baseline characteristics. The primary outcome was the development of AKI during the index admission. We also categorized the pararenal inflammation with the renal rim grade (RRG) and compared the incidence of AKI among different grades.
Results: Involvement of renal capsule was identified in 71 of 503 patients (14.1%). The incidence of AKI was significantly higher in these patients when compared with the matched controls (43/71, 60.6% vs. 12/71, 16.9%, p < 0.001). Moreover, mortality also differed between groups (12.7% vs. 1.4%, p = 0.017). Multivariable logistic regression showed that renal capsule involvement is an independent risk factor of AKI (odds ratio, 4.355; 95% confidence interval, 1.434, 13.230, p = 0.009). Patients with RRG grade III had a significantly higher incidence of AKI than the other two grades (60.6% for Grade III, 17.1% for Grade II, and 3.8% for Grade I, p < 0.001).
Conclusion: Involvement of renal capsule is associated with higher AKI incidence and mortality.

背景：急性胰腺炎(Acute pancreatitis, AP)以胰腺及胰周炎症为核心病理特征。肾包膜受累指胰周炎症突破吉氏筋膜(Gerota fascia)，且计算机断层扫描(Computed Tomography, CT)影像上肾缘征(renal rim sign)消失。然而，其与急性胰腺炎的重要并发症急性肾损伤(Acute kidney injury, AKI)之间的关联却鲜有研究。
目标：本研究旨在评估急性胰腺炎患者队列中肾包膜受累与急性肾损伤的相关性。
方法：本研究回顾性筛选了2018年1月至2019年12月期间因急性胰腺炎住院的全部患者。肾包膜受累情况由经验丰富的放射科医师依据CT影像进行判读。采用倾向性得分匹配(Propensity score matching, PSM)以校正组间样本量及基线特征的偏倚。本研究的主要结局为患者本次住院期间急性肾损伤的发生情况。此外，我们依据肾缘分级(renal rim grade, RRG)对肾周炎症进行分型，并比较不同分级组别间急性肾损伤的发生率。
结果：503例患者中共71例（14.1%）出现肾包膜受累。与匹配后的对照组相比，该组患者的急性肾损伤发生率显著更高（43/71，60.6% vs 12/71，16.9%，p < 0.001）。此外，两组患者的死亡率亦存在显著差异（12.7% vs 1.4%，p = 0.017）。多变量logistic回归分析显示，肾包膜受累是急性肾损伤的独立危险因素（比值比=4.355；95%置信区间：1.434~13.230，p = 0.009）。肾缘分级Ⅲ级患者的急性肾损伤发生率显著高于其余两个分级（Ⅲ级60.6%、Ⅱ级17.1%、Ⅰ级3.8%，p < 0.001）。
结论：肾包膜受累与更高的急性肾损伤发生率及死亡率显著相关。