Postoperative Serum Hyperamylasemia Adds Sequential Value to the Fistula Risk Score in Predicting Pancreatic Fistula after Pancreatoduodenectomy

Abstract

Objective: To evaluate whether postoperative serum hyperamylasemia (POH), with drain fluid amylase (DFA) and C-reactive protein (CRP), improves the Fistula Risk Score (FRS) accuracy in assessing the risk of a postoperative pancreatic fistula (POPF). Summary Background Data: The FRS predicts POPF occurrence using intraoperative predictors with good accuracy but intrinsic limits. Methods: Outcomes of patients who underwent pancreaticoduodenectomies between 2016 and 2021 were evaluated across FRS-risk zones and POH occurrence. POH consists of serum amylase activity greater than the upper limit of normal (52 U/l), persisting within the first 48 hours postoperatively (postoperative day –POD– 1 and 2). Results: Out of 905 pancreaticoduodenectomies, some FRS elements, namely soft pancreatic texture (odds ratio (OR) 11.6), pancreatic duct diameter (OR 0.80), high-risk pathologic diagnosis (OR 1.54), but not higher blood loss (OR 0.99), were associated with POH. POH was an independent predictor of POPF, which occurred in 46.8% of POH cases (P<0.001). Once POH occurs, POPF incidence rises from 3.8% to 42.9%, 22.9% to 41.7%, and 48.9% to 59.2% in patients intraoperatively classified at low, moderate and high FRS risk, respectively. The predictive ability of multivariable models adding POD 1 drain fluid amylase, POD 1-2 POH and POD 3 C-reactive protein to the FRS showed progressively and significantly higher accuracy (AUC FRS=0.82, AUC FRS-DFA=0.85, AUC FRS-DFA-POH=0.87, AUC FRS-DFA-POH-CRP=0.90, DeLong always P<0.05). Conclusions: POPF risk assessment should follow a dynamic process. The stepwise retrieval of early, postoperative biological markers improves clinical risk stratification by increasing the granularity of POPF risk estimates and affords a possible therapeutic window before the actual morbidity of POPF occurs.

Either High or low Risk

“…The accepted risk factors for POH and POPF appear to be similar, consisting of the macroscopic surrogates of a “healthy” gland, such as a soft pancreatic texture and a small MPD diameter. These same features represent the common ground of those intraoperative risk scores, indicating the selective use of mitigation strategies 7,10,29 …”

“…These same features represent the common ground of those intraoperative risk scores, indicating the selective use of mitigation strategies. 7,10,29 Many attempts have been made to correlate objective, histopathologic pancreatic measures such as Ac, fat content, and fibrosis to postoperative complications. 15,16,30,31 Recently, in the largest series available, Partelli et al 18 found that POPF was associated with Ac and inversely associated with fibrosis but not fat, consistent with previous studies.…”

Serum Creatinine and Amylase in Drain to Predict Pancreatic Fistula Risk after Pancreatoduodenectomy

“…Like POD1 DFA, serum markers are not reliant on subjective judgement and can be used in dynamic risk monitoring. Several markers including serum amylase [7], lipase [21,22], interleukin-6 [22], WBC [23], and CRP [24] have been found to correlate with CR-POPF. Therefore, stratifying risk based on a Several serum markers were routinely assessed in our department, such as CRP, WBC count, and aspartate transaminase.…”

“…For example, the combination of serum C-reactive protein (CRP) on POD 3 and DFA on POD 1 has a sensitivity and specificity of 87.4 and 90.9%, respectively, to predict CR-POPF [ 6 ]. Serum amylase also adds sequential value to the Fistula Risk Score in predicting CR-POPF after PD [ 7 ]. Most predictors associate with inflammation, and their combinations with DFA >5,000 U/L are rarely explored.…”

Serum amylase on postoperative day one is a strong predictor of pancreatic fistula after pancreaticoduodenectomy: a retrospective cohort

“…Although an SA value ≥120 IU/L on PoD 1 was not specific to CR-POPF, it outperformed other risk factors in predicting POPF formation. The advantage of this predictive ability may be that it provides an additional contribution to the POPF risk score [ 2 ], which includes endogenous and intraoperative variables, as noted in recently published strong evidence [ 31 ] As it is known, the most important endogenous POPF risk factor is the soft pancreatic remnant texture. Ideally, intraoperative gland palpation by a senior surgeon is adequate to assess pancreatic remnant stiffness [ 13 , 25 ].…”