Timing of Transmural Stent Removal in Necrotizing Pancreatitis

Study Overview
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Brief Summary
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Although metal stents have been widely used in the endoscopic step-up approach for necrotizing pancreatitis, the exact timing of transmural stent removal has not been well studied. In this prospective, open-label, randomized controlled study, we recruited and enrolled consecutive patients with necrotizing pancreatitis undergoing endoscopic transmural necrosectomy. Eligible participants were randomly assigned to case group (a novel strategy in which the stents were removed during the last necrosectomy when the necrosectomy endpoint was achieved) and control group (the conventional strategy in which the stents were removed after the last necrosectomy when clinical symptoms were relieved and fluid was nearly completely resolved confirmed by imaging). The primary endpoint was the incidence of composite complications within three months of enrollment.

Detailed Description
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Over the last decade, approaches to managing necrotizing pancreatitis have evolved from open surgery to a minimally invasive approach due to the efficacy and lower morbidity and mortality rates of the latter technique. As one of minimally invasive approaches, endoscopic step-up approach, with transmural drainage whenever feasible and subsequent necrosectomy as required, was first described in 1996 and has evolved to first-line therapy for symptomatic necrotizing pancreatitis. However,The exact timing of transmural stent removal has not been well studied. The conventional strategy for stent removal in the published guidelines has been that patients should undergo follow-up imaging and stent removal at 4-8 weeks if walled-off necrosis has resolved. Here, we introduced a novel strategy in which the stents were removed during the last necrosectomy when the endpoint of endoscopic transmural necrosectomy was achieved, that was, the necrotic tissue was nearly completely removed, and the pink granulation tissue lining the wall was uncovered. Compared to the conventional strategy, the novel strategy avoided one endoscopy procedure. The present study is the first prospective, open-label, randomized controlled study to investigate the efficacy and safety of the novel strategy. We recruited and enrolled consecutive patients with necrotizing pancreatitis undergoing endoscopic transmural necrosectomy. Eligible participants were randomly assigned to case group (a novel strategy in which the stents were removed during the last necrosectomy when the necrosectomy endpoint was achieved) and control group (the conventional strategy in which the stents were removed after the last necrosectomy when clinical symptoms were relieved and fluid was nearly completely resolved confirmed by imaging). The primary endpoint was the incidence of composite complications within three months of enrollment.

Official Title
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Timing of Transmural Stent Removal in Necrotizing Pancreatitis Undergoing Endoscopic Transmural Necrosectomy: A Randomized Controlled Study

Conditions
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Acute Pancreatitis, Necrotizing Pancreatitis, Walled-Off Necrosis

Intervention / Treatment
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* Procedure: Stent removed by the novel strategy
* Procedure: Stent removed by the conventional strategy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients diagnosed with necrotizing pancreatitis according to the 2012 Atlanta classification criteria; Patients aged between 18 and 65 years; Patients who signed the informed consent; Exclusion Criteria: Patients without transmural stent placement; Patients with transmural plastic stent not metal stent placement before enrollment; Patients who underwent endoscopic transmural necrosectomy in other hospitals before admission; Patients complicated with chronic pancreatitis; Patients complicated with pancreatic tumor; Pregnant or lactating women.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: The novel strategy group<br>The stents were removed during the last necrosectomy when the endpoint of necrosectomy was achieved | Procedure: Stent removed by the novel strategy<br>* The stent was removed during the last necrosectomy when the endpoint of necrosectomy was achieved；<br>|
| Active Comparator: The conventional strategy group<br>The stent was removed after the last necrosectomy when clinical symptoms were relieved and fluid was nearly completely resolved confirmed by CT image | Procedure: Stent removed by the conventional strategy<br>* The stent was removed after the last necrosectomy when clinical symptoms were relieved and fluid was nearly completely resolved confirmed by CT image.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of composite complications | The composite complications included new-onset organ failure or systemic complications、new-onset infectious pancreatic necrosis、abdominal or gastrointestinal bleeding, intestinal fistula, stent occlusion and stent migration. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of technical success | Technical success was defined by stent removed successfully. | 3 months | 
| The incidence of clinical success | Clinical success was defined as nearly completely resolution or <2 cm of collection assessed by image at the three-month follow-up without additional open surgery or death. | 3 months | 
| The number of endoscopic transmural necrosectomy sessions | Total sessions of patients undergoing endoscopic transmural necrosectomy. | 3 months | 
| The number of additional endoscopic transmural necrosectomy sessions after stent removal | Additional sessions of patients undergoing endoscopic transmural necrosectomy. after stent removal. | 3 months | 
| Length of stent placement | The duration time from stent placement to stent removal. | 3 months | 
| The incidence of open surgery | The incidence of patients needing open surgery after minimally invasive treatment. | 3 months | 
| All-cause mortality | The mortality whatever the cause is. | 3 months | 
| Length of hospital stay | The length of hospital stay due to necrotizing pancreatitis. | 3 months | 
| The incidence of readmission | The incidence of readmission after index discharge due to pancreatitis related problems. | 12 months | 
| The hospital cost | The hospital cost during hospitalization. | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Necrotizing pancreatitis, Endoscopic transmural necrosectomy, Lumen-apposing metal stent