Nomogram for assistant diagnosing acute suppurative cholangitis: a case-control study.

Background: Acute suppurative cholangitis (ASC) lacks sensitive and specific preoperative diagnostic criteria. Some researchers suggest treating ASC as severe cholangitis. This study aimed to explore the relationship between the Tokyo Guidelines 2018 (TG18) grading system for acute cholangitis (AC) and the diagnosis of acute suppurative cholangitis (ASC), searching for independent risk factors of ASC and develop a nomogram to discriminate ASC from acute nonsuppurative cholangitis (ANSC) accurately.

Methods: After applying the inclusion and exclusion criteria, 401 patients with acute cholangitis (AC) were retrospectively analyzed at Nanjing First Hospital between January 2015 and June 2023. SPSS version 27.0 and R studio software were used to analyze data obtained from medical records. The results were validated in a prospective cohort of 82 AC patients diagnosed at Nanjing First Hospital between July 2023 and February 2024.

Results: Among the 401 patients, 102 had suppurative bile (the ASC group; AC grade I: 40 [39.2%], AC grade II: 27 [26.5%], AC grade III: 35 [34.3%]), whereas 299 did not have (the ANSC group; AC grade I: 157 [52.5%], AC grade II: 92 [30.8%], AC grade III: 50 [16.7%]). The specificity of ASC for diagnosing moderate-to-severe cholangitis is 79.7%. Multivariate logistic regression analysis identified concurrent cholecystitis, CRP, PCT, TBA, and bile duct diameter as independent risk factors for suppurative bile, and all of these factors were included in the nomogram. The calibration curve exhibited consistency between the nomogram and the actual observation, and the area under the curve was 0.875 (95% confidence interval: 0.835-0.915), sensitivity was 86.6%, and specificity was 75.5%.

Conclusion: Suppurative bile is a specific indicator for diagnosing moderate-to-severe cholangitis. However, diagnosing ASC with AC grade II and AC grade III has the risk of missed diagnosis as the sensitivity is only 60.8%. To improve the diagnostic rate of ASC, this study identified concurrent cholecystitis, CRP, PCT, TBA, and preoperative bile duct diameter as independent risk factors for ASC, and a nomogram was developed to help physicians recognize patients with ASC.