Validation of the novel QNI classification for Walled-Off Pancreatic Necrosis in the Portuguese setting

Aims Currently, the therapeutic approach for walled-off necrosis (WON) is decidedbased on the patient's clinical presentation and evolution. However, the QNIclassification – quadrant (“Q”), necrosis (“N”), infection (“I”) – has recently beenproposed, based on clinical and radiological parameters. This classification aims tostandardize WON terminology, stratify disease severity, and, ultimately, guide theideal therapeutic approach for each patient.This study aimed to assess the accuracy of the QNI classification to predictoutcomes of endoscopically drained WON in the Portuguese setting.

Methods A retrospective multicentric analysis was conducted on a cohort of patients withendoscopically drained WON, from January 2016 to August 2024. Patients weredivided into low- and high-risk groups according to the QNI classification (Group 1and Group 2, respectively), which was applied following a review of clinical recordsby a gastroenterologist and radiologist. Clinical and procedural outcomes wereevaluated using descriptive and comparative statistics to determine differencesbetween the two groups.

Results A total of 53 patients were included (mean age 63.3±17.4 years; 52.8% male),with 46 (86.8%) drained using lumen-apposing metal stents (LAMS), 6 (11.3%)using double-pigtail plastic stents (DPPS), and 1 (1.9%) using both LAMS andDPPS. After applying the QNI classification, five patients were included in Group 1(9.4%) and 48 in Group 2 (90.6%). Although the differences observed did notreach statistical significance, it was noted that patients in Group 2 exhibited ahigher need for admission to intensive or intermediate care units (0% vs 45.8%, P=0.068), higher recurrence rate of collections (0% vs 5.4%, P=1), and highermortality (0% vs 22.9%, P=0.571), a lower clinical success rate (100% vs 72.9%,P=0.317), longer mean duration of hospital stay (39 [IQR 29-51] vs 63 [IQR 31-83] days, P=0.180), and required more necrosectomies (1 [IQR 0-2] vs 2 [IQR 1-2], P=0.69).Per se, the percentage of necrosis in the collection showed a statisticallysignificant association with the time to resolution of the collection in the cohort(< 30%: 66 days [IQR 36-162]; 30-60%: 40 days [IQR 16-118];>60%: 148 days[IQR 72-268], H(2)=6.53, P=0.038) [1] [2].

Conclusions In this Portuguese cohort, although statistical significance was limited due to thesmall sample size, the high-risk QNI classification identified patients withunfavourable outcomes compared to the low-risk group, which is consistent withthe existing literature. It is necessary to repeat this analysis with larger samplesizes to validate these results.

Publication History

Article published online:
27 March 2025

• References

• 1 Novel classification system for walled-off necrosis: a step toward standardized nomenclature and risk-stratification framework. Gastrointest Endosc 2023; 97 (02): 300-308
• 2 Arvanitakis M, Dumonceau JM, Albert J. et al. Endoscopic management of acute necrotizing pancreatitis: European Society of Gastrointestinal Endoscopy (ESGE) evidence-based multidisciplinary guidelines. Endoscopy 2018; 50 (05): 524-546