Endoscopic management of pancreatic necrosis

A Protocolized Management of Walled-Off Necrosis (WON) Reduces Time to WON Resolution and Improves Outcomes

BACKGROUND AND AIMS

Patients with infected or symptomatic walled-off necrosis (WON) have high morbidity and health care utilization. Despite the recent adoption of nonsurgical treatment approaches, WON management remains nonalgorithmic. We investigated the impact of a protocolized early necrosectomy approach compared with a nonprotocolized, clinician-driven approach on important clinical outcomes.

METHODS

Records were reviewed for consecutive patients with WON who underwent a protocolized endoscopic drainage with a lumen-apposing metal stent (cases), and for patients with WON treated with a lumen-apposing metal stent at the same tertiary referral center who were not managed according to the protocol (control subjects). The protocol required repeat cross-sectional imaging within 14 days after lumen-apposing metal stent placement, with regularly scheduled endoscopic necrosectomy if WON diameter reduction was <50%. Control patients were treated according to their clinician's preference without an a priori strategy. Inverse probability of treatment weighting-adjusted analysis was used to evaluate the influence of being in the protocolized group on time to resolution.

RESULTS

A total of 24 cases and 47 control subjects were included. There were no significant differences in baseline characteristics. Although numbers of endoscopies and necrosectomies were similar, cases had lower adverse event rates, shorter intensive care unit stay, and required nutritional support for fewer days. On matched multivariate Cox regression, cases had earlier WON resolution (hazard ratio, 5.73; 95% confidence interval, 2.62-12.5). This was confirmed in the inverse probability of treatment weighting-adjusted analysis (hazard ratio, 3.4; 95% confidence interval, 1.92-6.01).

CONCLUSIONS

A protocolized strategy resulted in faster WON resolution compared with a discretionary approach without the need for additional therapeutic interventions, and with a better safety profile and decreased health care utilization.

Novel classification system for walled-off necrosis: a step toward standardized nomenclature and risk-stratification framework

BACKGROUND AND AIMS

The optimal therapeutic approach for walled-off necrosis (WON) is not fully understood, given the lack of a validated classification system. We propose a novel and robust classification system based on radiologic and clinical factors to standardize the nomenclature, provide a framework to guide comparative effectiveness trials, and inform the optimal WON interventional approach.

METHODS

This was a retrospective analysis of patients who underwent endoscopic management of WON by lumen-apposing metal stent placement at a tertiary referral center. Patients were classified according to the proposed QNI classification system: quadrant ("Q"), represented an abdominal quadrant distribution; necrosis ("N"), denoted by the percentage of necrosis of WON; and infection ("I"), denoted as positive blood culture and/or systemic inflammatory response syndrome reaction with a positive WON culture. Two blinded reviewers classified all patients according to the QNI system. Patients were then divided into 2 groups: those with a lower QNI stratification (≤2 quadrants and ≤30% necrosis; group 1) and those with a higher stratification (≥3 quadrants, 2 quadrants with ≥30% necrosis, or 1 quadrant with >60% necrosis and infection; group 2). The primary outcome was mean time to WON resolution. Secondary procedural and clinical outcomes between the groups were compared.

RESULTS

Seventy-one patients (75% men) were included and stratified by the QNI classification; group 1 comprised 17 patients and group 2, 54 patients. Patients in group 2 had a higher number of necrosectomies, longer hospital stays, and more readmissions. The mean time to resolution was longer in group 2 than in group 1 (79.6 ± 7.76 days vs 48.4 ± 9.22 days, P = .02). The mortality rate was higher in group 2 (15% vs 0%, P = .18).

CONCLUSIONS

Despite the heterogeneous nature of WON in severe acute pancreatitis, a proposed QNI system may provide a standardized framework for WON classification to inform clinical trials, risk-stratify the disease course, and potentially inform an optimal management approach.

Outcomes of early endoscopic intervention for pancreatic necrotic collections: a matched case-control study

BACKGROUND AND AIMS

Pancreatic necrosis may be categorized as an acute necrotic collection (ANC) or walled-off necrosis (WON) based on complete encapsulation by a wall and collection age (≤4 weeks or >4 weeks). Endoscopic intervention of WON has become the standard of care, but little is known regarding the safety and efficacy of endoscopic intervention of pancreatic necrosis ≤4 weeks from disease onset.

METHODS

Retrospective review of medical records and imaging studies of all patients undergoing early endoscopic intervention of pancreatic necrosis between 2008 and 2018 was carried out at 1 referral center. Patients who underwent previous interventional treatment were excluded. Control WON patients were matched to early intervention cases. The primary outcome was defined as resolution of the collection after endoscopic treatment, without surgery.

RESULTS

Nineteen patients with early intervention were identified. The most common indication for intervention was infection. Median age of these collections at the time of initial endoscopic intervention was 23 days (range, 15-27 days), and all collections had a partial or complete wall discernable on contrast-enhanced CT. Eleven patients underwent concurrent endoscopic necrosectomy. The primary outcome was achieved in all patients in the early intervention group. Total duration of therapy was longer for early intervention compared with controls (103 vs 69 days, P = .042), with no mortality and similar adverse event rates compared with controls.

CONCLUSIONS

Endoscopic intervention of pancreatic necrosis in the third and fourth weeks of illness appears effective and safe when a partial collection wall is present on cross-sectional imaging studies, with outcomes paralleling those reported for intervention of WON.