**6. Pancreatic pseudocysts (PPCs)**

One-third of the patients with CP developed PPCs. In the evaluation, potentially malignant mucinous neoplasms should have been excluded. Transmural drainage, transpapillary drainage, or a combination of these techniques can be used in endoscopic treatment. The transpapillary route is only appropriate for half of the PPCs, which are small (<50 mm) and communicate with the MPD in the head or body of the pancreas [42]. Clinical success is defined as resolving the symptoms with complete resolution of PPC or a decrease in PPC to less than 2 cm [43]. Spontaneous regression of chronic PPCs is rare and typically occurs in PPCs of <4 cm. Symptomatic PPCs that cause abdominal pain, gastric outlet obstruction, early satiety, jaundice, weight loss, infection, or bleeding should be treated. Progressive growth of a PPC is an indication for some authors; however, others suggest follow-up for symptoms. If significant vessel compression occurs due to a PPC, the risk-benefit ratio should be checked before intervention.

Endoscopic drainage of PPCs has higher clinical success, shorter hospital stay than percutaneous drainage, and similar morbidity and recurrence rates [44]. Percutaneous drainage seems to be a better option when a PCC is not endoscopically accessible. A meta-analysis of 255 patients reported that surgery had a higher success rate, higher hospital cost, and extended hospital stay with similar morbidity and recurrence rates [45]. Current guidelines suggest endoscopic treatment for an uncomplicated PPC in CP over percutaneous or surgery, if accessible.

S-MRCP is a suggested method for evaluating the PPC and MPD anatomy before the procedure, which has an accuracy of >90% for diagnosing MPD rupture. In the management, transmural drainage is adequate in the absence of MPD rupture. In cases of partial rupture, treatment should include bridging the rupture with a stent. Complete MPD rupture (disconnected pancreatic duct syndrome) is associated with a high recurrence rate. Therefore, long-term indwelling of transmural double pigtail stents should be considered [46]. ERCP is regarded as the gold standard for diagnosing MPD rupture and carries an infection risk for a patient with a sterile PPC [47].

### *Endoscopic Management of Chronic Pancreatitis DOI: http://dx.doi.org/10.5772/intechopen.107321*

Transmural drainage can be performed using EUS or a conventional approach. EUS-guided transmural drainage has a higher technical success rate; however, there are no differences in the complications or clinical success. This difference occurs because of non-bulging collections, observed in approximately half of all PPCs [48]. Double pigtail plastic stents are generally preferred for PPCs. The number and diameter of these stents were not associated with clinical success [49]. biliary FCSEMSs could also be preferred when disconnected pancreatic duct syndrome is ruled out, and the duration is expected to be lesser than 6 weeks. A double pigtail plastic stent should be inserted through the biliary FCSEMS to prevent migration. Current guidelines suggest retrieval of transmural plastic stents at least 6 weeks after PPC regression; however, long-term indwelling of transmural plastic stents is needed for disconnected pancreatic duct syndrome. Retrospective studies have reported that long-term indwelling stents are highly effective and low PPC recurrence has been reported. PPC recurrence is associated with stent migration within 6 months and MPD disruption at the pancreatic head. Lumen-apposing metal stents can also be used for PPC in CP; however, it is less cost-effective than plastic stents.

Extrahepatic portal hypertension occurs during CP in ≥15% of all patients [50]. In this case, the EUS-guided transmural route was suggested. In two case series with 26 patients, the bleeding rate was 4% [51]. A pseudoaneurysm can occur in 1–10% of the cases during the course of CP [52]. Arterial embolization is suggested before the endoscopic drainage of a PPC.
