Clinical evaluation of the M-ANNHEIM classification: Development of the M-ANNHEIM-Surgery-Score as a new tool to monitor patients with chronic pancreatitis.

Objectives:  The M-ANNHEIM classification of chronic pancreatitis (CP) stratifies degrees of disease severity according to the M-ANNHEIM-Severity-Score. We aimed to demonstrate the clinical usefulness of the M-ANNHEIM-Severity-Score in quantifying and predicting the frequency of pancreatic surgery, and to establish the M-ANNHEIM-Surgery-Score as a simplified system for patient surveillance regarding the demand of pancreatic surgery.

Methods:  We performed a retrospective, cross-sectional study with 741 CP patients (Mannheim/Germany, n = 537; Gießen/Germany, n = 100; Donetsk/Ukraine, n = 104) categorized according to the M-ANNHEIM classification.

Results:  We observed a significantly higher M-ANNHEIM-Severity-Score in patients that were classified within 7 days preceding pancreatic surgery than in individuals that did not require surgery (p < 0.001, Mann-Whitney-U-test). Using a logistic regression analysis with all variables of the M-ANNHEIM-Severity-Score, we established the M-ANNHEIM-Surgery-Score as a simplified new tool to identify patients that may require surgery. A receiver operating characteristic-analysis revealed a cut-off-value of 9 points within the M-ANNHEIM-Surgery-Score to identify these individuals (sensitivity 78.7 %, specificity 91 %). Based on the M-ANNHEIM-Surgery-Score, we defined three categories for demand of surgery with frequencies of pancreatic operations of 1.6 % (n = 7/440) in the "Baseline-Demand"-category, 7 % (n = 12/172) in the "Low-Demand"-category (p < 0.0001, Chi-square-test, OR 4.6, Confidence Interval (CI) 1.8 - 12), and 54 % (n = 70/129) in the "High-Demand"-category (p < 0.0001, OR 73, CI 32 - 167). Patients that were categorized for the "High-Demand"-category, but were not operated on, had a significantly increased ratio of clinical features that hamper performance of surgery (p < 0.001, Chi-square-test).

Conclusions:  The M-ANNHEIM-Surgery-Score represents a useful tool to monitor patients with CP and to estimate the demand of surgery in CP.