Early and Sustained Elevation in Serum Pancreatic Amylase Activity: A Novel Predictor of Morbidity After Pancreatic Surgery

Objective: To characterize early postoperative serum pancreatic amylase (spAMY) trends after pancreatic resections.

Summary background data: A postoperative spAMY elevation is a common finding but uncertainties remain about its meaning and prognostic implications.

Methods: Analysis of patients who consecutively underwent pancreatectomy from 2016 to 2019. spAMY activity was assessed from postoperative day (POD) 0 to 3. Different patterns of spAMY have been identified based on the spAMY standard range (10-52 U/l).

Results: Three patterns were identified: (#1) spAMY values always < the lower limit of normal/within the reference range /a single increase in spAMY > upper limit of normal at any POD; (#2) Sustained increase in spAMY activity on POD 0 + 1; (#3) Sustained increase in spAMY activity including POD 1 + 2. Shifting through spAMY patterns was associated with increase morbidity (21% in #1 to 68% in #3 at POD 7; log rank < 0.001). Almost all severe complications (at least Clavien-Dindo ≥3) occurred in patients with pattern #3 (15% vs 3% vs 5% in #1 and #2 at POD 7, P = 0.006), without difference considering >3-times or >the spAMY normal limit ( P = 0.85). POPF (9% in #1 vs 48% in #3, P < 0.001) progressively increased across patterns. Pre-operative diabetes (OR 0.19), neoadjuvant therapy (OR 0.22), pancreatic texture (OR 8.8), duct size (OR 0.78), and final histology (OR 2.2) were independent predictors of pattern #3.

Conclusions: A sustained increase in spAMY activity including POD 1 + 2 (#3) represents an early postoperative predictor of overall and severe early morbidity. An early and dynamic evaluation of spAMY could crucially impact the subsequent clinical course with relevant prognostic implications.