Correlation analysis of computed tomography imaging score with the presence of acute kidney injury in severe acute pancreatitis

The Involvement of Renal Capsule Is Associated With Acute Kidney Injury in Patients With Acute Pancreatitis

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.

Potential role of imaging for assessing acute pancreatitis-induced acute kidney injury

Acute kidney injury (AKI) is a common complication of acute pancreatitis (AP) that is associated with increased mortality. Conventional assessment of AKI is based on changes in serum creatinine concentration and urinary output. However, these examinations have limited accuracy and sensitivity for the diagnosis of early-stage AKI. This review summarizes current evidence on the use of advanced imaging approaches and artificial intelligence (AI) for the early prediction and diagnosis of AKI in patients with AP. CT scores, CT post-processing technology, Doppler ultrasound, and AI technology provide increasingly valuable information for the diagnosis of AP-induced AKI. Magnetic resonance imaging (MRI) also has potential for the evaluation of AP-induced AKI. For the accurate diagnosis of early-stage AP-induced AKI, more studies are needed that use these new techniques and that use AI in combination with advanced imaging technologies.

The Value of Modified Renal Rim Grade in Predicting Acute Kidney Injury Following Severe Acute Pancreatitis

OBJECTIVE

To retrospectively determine the value of modified renal rim grade (MRRG) in predicting acute kidney injury (AKI) in the early phase of severe acute pancreatitis (SAP).

METHODS

This institutional review board-approved retrospective study included patients with SAP who underwent abdominal contrast-enhanced computed tomography (CT) within 48 hours after disease onset. Modified renal rim grade, renal rim grade, CT severity index, modified CT severity index, extrapancreatic inflammation on CT scores, and posterior pararenal (PPR) space involvement were assessed. Clinical data, including bedside index of severity in acute pancreatitis and New Japanese Severity Scoring system scores, were collected. Primary end points were AKI and mortality. Scores were evaluated by receiver operating characteristic curve analysis. Correlational analyses between MRRG scores and the other scores were performed with Spearman analysis.

RESULT

One hundred five consecutive patients were enrolled in our study. The areas under the curve (AUCs) of MRRG in predicting AKI (0.90) and mortality (0.83) were comparable to extrapancreatic inflammation on CT (0.89 and 0.85, P > 0.05) and were higher than those of the other CT scores (P < 0.05). Modified renal rim grade score of greater than 4 yielded sensitivities and specificities of 81% and 89% for predicting AKI and 88% and 66% for mortality. Modified renal rim grade correlated moderately with bedside index of severity in acute pancreatitis (Spearman r = 0.47) and New Japanese Severity Scoring system (r = 0.43) scores. Besides, the prevalence of PPR space involvement in nonrecovery AKI patients was higher than that in recovery patients (94% vs 36%, P < 0.05).

CONCLUSIONS

Modified renal rim grade is well correlated with the occurrence of AKI and mortality in SAP. The PPR space involvement is a promising prognostic factor for nonrecovery of AKI in SAP patients.

Extra-pancreatic necrosis alone: Contours of an emerging entity

Acute pancreatitis is of two morphologic types: interstitial edematous pancreatitis that is not associated with any tissue necrosis and necrotizing pancreatitis wherein the pancreatic parenchyma with or without varying amount of extra-pancreatic tissue/fat undergoes necrosis. Necrotizing pancreatitis has a worse outcome compared with interstitial pancreatitis because of increased severity related to a heightened systemic response and cytokine storm associated with tissue necrosis. Increasingly, an entity of extra-pancreatic necrosis (EPN) alone, wherein the pancreatic parenchyma is normal on an enhanced computed tomographic scan but the peri-pancreatic tissues undergo necrosis, is being recognized. Available data suggest that the outcomes in patients with EPN alone are between the excellent prognosis of patients with interstitial and adverse prognosis of patients with necrotizing pancreatitis. The extent of EPN also seems to determine the outcome. This review summarizes the currently available literature on this entity and various radiological scores that have been suggested to determine the presence and stage of EPN.