RESUMO
AIM: To determine predictors of clinically relevant pancreatic fistulas (CRPF) by measuring drain fluid amylase (DFA) in the early postoperative period. METHODS: This prospective clinical study included 382 patients with periampullary tumors that were surgically resected at our department between March 2005 and October 2012. A cephalic duodenopancreatectomy (DP) was performed on all patients. Two closed suction drains were placed at the end of the surgery. The highest postoperative DFA value was recorded and analyzed during the first three postoperative days and on subsequent days if the drains were kept longer. Pancreatic fistula (PF) was classified according to the International Study Group of Pancreatic Fistula (ISGPF) criteria. Postoperative complications were defined according to the Dindo-Clavien classification. All data were statistically analyzed. The optimal thresholds of DFA levels on the first, second and third postoperative days were estimated by constructing receiver operating curves, generated by calculating the sensitivities and specificities of the DFA levels. The DFA level limits were used to differentiate between the group without PF and the groups with biochemical pancreatic fistula (BPF) and CRPF. RESULTS: Pylorus-preserving duodenopancreatectomy was performed on 289 (75.6%) patients, while the remaining patients underwent a classic Whipple procedure (CW). The total incidence of PF was 37.7% (grade A 22.8%, grade B 11.0% and grade C 3.9%). Soft pancreatic texture (SPT) was present in 58.3% of patients who developed PF. Mortality was 4.2%. The median DFA value on the first postoperative day (DFA1) in patients who developed PF was 4520 U/L (range 350-99000 U/L) for grade A fistula (BPF) with a SPT and a diameter of the main pancreatic duct (MPD) of ≤ 3 mm. For grade B/C (CRPF), the median DFA1 value was 8501 U/L (range 377-92060 U/L) with a SPT and MPD of ≤ 3 mm. These values were significantly higher when compared to the patients who did not have PF (122; range 5-37875 U/L). The upper limit of DFA values for the first 3 postoperative days in the examined stages of PF were: DFA1 1200 U/L for the BPF and CRPF; DFA3 350 U/L for BPF and DFA3 800 U/L for CRPF. The determined values were highly significant and demonstrated a reliable diagnostic test for both BPF and CRPF. CONCLUSION: DFA1 ≥ 1200 U/L is an important predictive factor for PF of any degree. The trend of DFA3 (decrease of < 50%) compared to DFA1 is a significant factor in the differentiation of CRPF from transient BPF.
