Clinical trial involving patients with indication of endoscopic drainage of Pancreatic Collections with the aim to compare rates of displacement of two type of prothesis: with and without anti-migration systems

INTERVENTION: Cholangiopancreatography, Endoscopic Retrograde Control group: 21 volunteers of any gender and age with a pancreatic collection due to an episode of acute pancreatitis will be submitted to an endoscopic transmural drainage with a self‐expandable metallic stent without anti‐migration system. After 7 days of the procedure, the participant is submitted to another endoscopic control examination with pancreatography and placement of pancreatic stent if necessary. In 30 days, he returns with a new tomography to evaluate the collection resolution and possible removal of the stent. Experimental group: 21 volunteers of any sex and age with pancreatic collection due to an episode of acute pancreatitis will be submitted to an endoscopic transmural drainage with a self‐expandable metallic stent with anti‐migration system. Follow‐up exams/procedures will be similar to the control group. The choice of the stent (with and without anti‐migration system) was alleatory and performed after confirmation of the viability of the drainage. There may be a need for lavage with saline solution and debridement of the cyst in this and the following exams. Such procedures are described below. Transmural Drainage is performed with a therapeutic linear echoendoscope and with fluoroscopic guidance. An appropriate place for the initial puncture will be identified and the cavity of the organized collection will be accessed through the punction with a specific needle. Then a flexible guidewire will be inserted through the needle and curled into the cavity of the collection under fluoroscopic guidance. The punction needle is removed and the flexible guide wire is left. After, a transmural path is created with the passage of the cystotome with Electrocautery, creating a fistula. After the creation of the trasmural fistula, it will be placed the autoexpandablel fully covered metal stent with or without anti‐migration system (depending on randomization).If the stent cannot be inserted through the guidewire, directly into Device Endoscopy, Gastrointestinal Endosonography Natural Orifice Endoscopic Surgery Procedure/surgery Prostheses and Implants CONDITION: K00‐K93 Necrosis Pancreatic Pseudocyst Pancreatic pseudocyst; acute necrotizing pancreatitis; organized pancreatic necrosis The study will be conducted in human volunteers of the intervention (endoscopic drainage with self‐expandable metallic stent). Such pathologies must be due to a documented episode of acute pancreatitis causing compressive symptoms or clinical or laboratory or radiological signs of infection. However, it is mandatory that patients have clinical stability, without requiring cardiac inotropic support and/or vasopressors ; Pancreatic Pseudocyst ; Pseudocyst of pancreas ; Necrosis ; Pancreatitis, Acute Necrotizing Pancreatitis, Acute Necrotizing Pseudocyst of pancreas PRIMARY OUTCOME: Expected outcome 1; It is expected that the migration rate of the fully covered self‐expanding metal stents with anti‐migration systems will be lower than stents without anti‐migration system.; Migration of the stent wil be verified during the endoscopic and/or radiologic exams. It is defined as displacement of the stent into the cyst or into the lumen of the gastrointestinal tract.; We will observe the number and percentile of the migrated stents, which can occur right after intervention until its removal. SECONDARY OUTCOME: Expected outcome 2 ; Higher capability to access the collection through the stent to perform lavage and debriment with the stent with anti‐migration system. ; The capability will be observed during the first procedure and subsequent exams. ; We will collect the number and the percentile of times that the event occured. Expected outcome 3 ; Resolution of the collection observed in imaging exams at 1 to 3 months from the first intervention. ; The outcome will be verified with imaging exams with one to three months after inicial intervention. ; We will collect the number and the percentile of cases with complete, parcial and no resolution of the collection. Expected outcome 4 ; It is expected the same incidence of recurrence of the pancreatic collections. ; Verified in computed tomography as new collection at the site of the drainage, five and eleven months after removal of the stent. ; We will collect the number of participants in which recurrence occured. Expected outcome 5 ; Similar or slightly higher rate of adverse events related to the endoscopic procedures with stents with anti‐migration systems: defined and classified according to consensus of the American Society of Gastrointestinal Endoscopy (published in 2010 by Peter Cotton). It is expected to be more correlated with the type and gravity of the collection. ; Data verified during the procedure, 24 hours, 7 days, 1 month and 3 months after. ; We will collect the number and the percentile of times that the event occured. INCLUSION CRITERIA: Patients of any age; any gender; with the diagnosis of fluid pancreatic collection with definite ethiology of acute pancreatitis identified by abdominal radiological study after 4 weeks of onset of acute event; with symptoms such as pain or compression of the intra‐abdominal organs by the collection or infected collections or causing sepsis