Chylous ascites after pancreaticoduodenectomy: introduction of a grading system

Chylous ascites (CA) is a complication that follows thoracic and abdominal surgery, recognized after provocation by enteral feeding and characterized by its milky appearance from an elevated triglyceride level. The aim of this study was to evaluate incidence, management, and predisposing factors of CA and its impact on outcomes after pancreaticoduodenectomy.

Between 1996 and 2007, 609 consecutive patients underwent pancreaticoduodenectomy. Patients having a drain output with a milky appearance, and with a triglyceride level greater than 1.2 mmol/L, were compared with patients without significant drain production or with a low triglyceride level. Management of CA was reviewed.

Sixty-six patients had isolated CA (11%) of any measurable volume, 440 patients (72%) had no CA, and 109 patients (16%) were excluded from analysis. CA was diagnosed on postoperative day 6 (median; interquartile range 5 to 8), generally after introduction of a normal (polymeric low-chain-triglyceride) diet. Female gender (odds ratio, 1.79; 95% CI, 1.05 to 3.03) and chronic pancreatitis at pathology (odds ratio, 2.52; 95% CI, 1.19 to 5.32) were independently associated with development of isolated CA. A low-chain-triglyceride-restricted diet was initiated in 47 patients, 3 were started on total parenteral nutrition, and an expectative approach was followed in 16 patients. CA resolved after 3.5 days (median; interquartile range, 2 to 5). Isolated CA was significantly associated with prolonged hospital stay (p=0.002).

We propose a novel definition and grading system for CA after pancreaticoduodenectomy, according to which the incidence is 9%, with clinically significant CA occurring in 4% (grades B and C). Although female gender and (focal) chronic pancreatitis were associated with development of isolated CA, no predisposing factors that could readily anticipate CA were identified. Isolated CA was associated with prolonged hospital stay.