Does Drainage Timing Matter in Infected Necrotizing Pancreatitis?

— Dutch study found similar outcomes for immediate, postponed drainage

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 An MRI image of a pancreatic pseudocyst

Immediate drainage of infected necrotizing pancreatitis within 24 hours of diagnosis did not result in significantly fewer complications compared to postponed drainage, a small randomized controlled trial found.

In an intention-to-treat analysis of 104 patients, the mean (CCI) score over 6 months was similar for those who received either immediate drainage within 24 hours of diagnosis or postponed drainage until walled-off necrosis (57 vs 58 of 100, respectively), reported Marc G. Besselink, MD, PhD, of the University of Amsterdam in The Netherlands, and colleagues.

However, those in the immediate-drainage group had more invasive interventions, including necrosectomy and catheter drainage, compared to those in the postponed-drainage group (mean 4.4 vs 2.6 interventions), but had similar mortality rates at 6 months (13% vs 10%, respectively; RR 1.25, 95% CI 0.42-3.68), the authors wrote in the .

Interestingly, 39% of patients in the postponed-drainage group were treated with antibiotics instead of drainage, and 17 of 19 survived, they noted.

"These findings suggest that an initial conservative approach with antibiotics is justified when infected necrosis is diagnosed," the authors wrote.

The current standard for treating infected necrotizing pancreatitis involves a step-up approach, starting with catheter drainage, the authors said, an approach supported by recent guidelines "even in the early stages of disease."

However, Besselink's group noted that it was not known whether immediate catheter drainage could improve patient outcomes.

"As shown in the present study, nonoperative drainage in clinically stable patients is best delayed until the development of walled-off necrosis, which usually occurs 30 or more days after the onset of pancreatitis," wrote Todd H. Baron, MD, of the University of North Carolina at Chapel Hill, in an .

"Differentiating infected necrosis from sterile necrosis with concomitant ongoing systemic inflammatory response within the first few weeks after the onset of pancreatitis may be difficult, but there are established criteria to guide clinicians," Baron noted. "The distinction between infected and sterile necrosis is essential because infected necrosis is associated with significantly higher mortality, requires initiation of antibiotics that penetrate pancreatic tissue (tailored to available culture data), and often results in percutaneous, endoscopic, or surgical intervention (alone or in combination)."

The (Postponed or Immediate Drainage of Infected Necrotizing Pancreatitis) study involved 22 centers and included patients with acute pancreatitis who developed infected necrotizing pancreatitis, and could have endoscopic transluminal drainage or image-guided percutaneous drainage within 35 days of symptom onset.

Besselink and colleagues evaluated 104 patients from August 2015 to October 2019, and randomized them 1:1 to receive immediate drainage (n=55) or postponed drainage (n=49) after walled-off necrosis.

Infected necrosis was confirmed by presence of gas within pancreatic and peripancreatic necrosis on a contrast-enhanced CT scan, or a positive culture from fine-needle aspiration or positive Gram's stain within 14 days after onset of acute pancreatitis.

The primary outcome of the study was CCI score from randomization to 6 months, with follow-up at 3 and 6 months. was used to grade complications.

Patients had a mean age of 59, and 58% were men. About two-thirds had gallstones as the cause of their pancreatitis.

On average, immediate catheter drainage occurred at 24 days after symptom onset, while postponed drainage occurred 34 days after symptoms. Fifty-one of 55 patients in the immediate drainage-group underwent drainage within 24 hours of randomization. Pancreatic and peripancreatic necrosis was "largely or fully encapsulated" among 60% of patients in the immediate group and 70% in the postponed group, the authors said.

No significant differences occurred in the incidence of major complications between the immediate and postponed groups, respectively, including new organ failure (25% vs 22%), visceral perforation or enterocutaneous fistula (9% vs 8%), bleeding (15% vs 20%), pancreaticocutaneous fistula (11% vs 8%), or wound infection (0% vs 1%).

Average length of hospital stay was 59 days in the immediate group versus 51 days in the postponed group, and length of ICU stay did not differ between groups (12 days for each group), the authors noted.

The analysis had several limitations, the researchers acknowledged, including the small sample size and that CCI is only designed to assess post-operative complications. Also, the trial allowed for both surgical step-up and endoscopic approaches, though the endoscopic route "has gradually become the preferred treatment strategy," the authors noted. Additionally, not all necrotic collections could be reached endoscopically.

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    Zaina Hamza is a staff writer for , covering Gastroenterology and Infectious disease. She is based in Chicago.

Disclosures

Funding was provided by the Dutch government, Amsterdam UMC-University of Amsterdam, and the Fonds NutsOhra.

Besselink did not report any conflicts of interest. Some coauthors reported relationships with industry.

Baron reported affiliations with Cook Endoscopy, Olympus, Boston Scientific, Ambu, W.L. Gore, and Medtronic.

Primary Source

New England Journal of Medicine

Boxhoorn L, et al "Immediate versus postponed intervention for infected necrotizing pancreatitis" N Engl J Med 2021: DOI: 10.1056/NEJMoa2100826.

Secondary Source

New England Journal of Medicine

Baron TH, et al "Drainage for infected pancreatic necrosis -- is the waiting the hardest part?" N Engl J Med 2021; DOI: 10.1056/NEJMe2110313.