For patients with pancreatic pseudocysts, the efficacy of the new double mushroom head metal stent is considerable

Pancreatic pseudocyst is one of the complications of pancreatitis, as its recurrent symptoms have a significant impact on the quality of life of patients. At present, the treatment methods for pancreatic pseudocysts include surgical treatment, percutaneous puncture drainage, and endoscopic transluminal drainage. In recent years, endoscopic transluminal drainage has gradually become a standard treatment method, mainly guided by endoscopic ultrasound (EUS) to establish an effective drainage channel between the cyst and the stomach or duodenum, in order to achieve internal drainage of the cyst. In clinical practice, various forms of stents are usually placed between channels to ensure their good open state.

There are various types of stents in clinical practice, and the commonly used double pigtail stent has a low risk of stent displacement. However, due to its small inner diameter, stent blockage often occurs. Fully covered self expanding metal stents have advantages such as larger inner diameter, lower risk of blockage, and good drainage effect for cysts. In recent years, South Korea has produced a new type of double mushroom head stent (Figure 1), which has a larger diameter and length, and is equipped with a dedicated delivery catheter. Previous studies have found that this new stent has considerable clinical efficacy.

Cyst shown on MR

The gastric cavity is compressed and becomes smaller

Pseudocyst under endoscopic ultrasound

Rapid liquid outflow after stent placement

Research Int roduction

A study in South Korea has shown that for patients with symptomatic pancreatic pseudocysts, the use of a new double mushroom head metal stent can effectively alleviate symptoms, eliminate pancreatic cysts, and is safe. The article was published in the September issue of Gastrointestinal Endoscopy (2019, 90 (3): 507-513).

This study included patients with symptomatic pancreatic pseudocysts, which have a diameter greater than 6 cm, no internal partitions, and are adjacent to the gastric and duodenal cavities. Excluding individuals with solid components in pseudocysts, deceased individuals with encapsulated lesions, and individuals with pseudocysts that cannot be treated under EUS guidance. For enrolled patients, first EUS guided puncture is performed to establish a passage through the gastric or duodenal cavity and cyst, followed by dilation and reconstruction surgery and placement of a new double mushroom head stent. CT scan was performed 4 weeks after treatment to evaluate the drainage effect of the cyst (Figure 2).

Figure 2: Treatment of pancreatic pseudocyst using a new double mushroom head metal stent: A, CT shows a huge pancreatic pseudocyst; B. EUS guided transgastric cyst puncture surgery; C. Observe the guide wire entering the inside of the cyst under X-ray fluoroscopy; D. Insertion of SPAXUS stent under EUS guidance; E. Visible stent placement under X-ray fluoroscopy; F. Observing the successfully implanted stent under direct endoscopy; G. CT follow-up images after stent placement surgery; H. After stent placement, the stent function was observed to be good under endoscopy; I. Successfully remove the stent under endoscopy

A total of 34 patients were enrolled in the study, including 26 males and 8 females, with an average age of 51.7 years. The average diameter of pancreatic pseudocysts was 9.23 cm. Except for one patient who failed the stent release process, the remaining 33 patients successfully completed stent implantation, with a technical success rate of 97.1% (33/34); Among the 33 patients who successfully placed the stent, only 1 patient had poor drainage effect, while the remaining 32 patients achieved clinical symptom relief and cyst disappearance, with a clinical success rate of 94.1% (32/34). There were 3 cases of pseudocyst infection and 1 case of stent dysfunction during the perioperative period, with a complication rate of 11.8% (4/34).

Expert comments

Commentary expert: Zhang Shutian, Beijing Friendship Hospital Affiliated to Capital Medical University

Traditionally, most patients with pancreatic pseudocysts require surgical treatment to achieve cyst drainage and elimination. With the development of endoscopic technology, endoscopic treatment of pancreatic pseudocysts has gradually become the mainstream treatment method, with considerable efficacy and safety, but there are also certain technical difficulties.

The core step of endoscopic treatment for pseudocysts is to establish a channel between the digestive tract lumen and the cyst, and place a appropriately sized stent to achieve internal drainage of the cyst. The diameter and length of the stent both affect the drainage effect. Currently, the commonly used double pigtail plastic stent has a smaller diameter and is prone to blockage; The metal covered stent has a shorter length and is prone to displacement, which affects the therapeutic effect; In recent years, the newly launched double mushroom head metal stent has a larger inner diameter and can be adjusted to the appropriate size according to the length of the digestive tract wall and cyst channel.

This study is the first multicenter prospective study targeting the novel stent, aiming to evaluate its efficacy in patients with symptomatic pancreatic pseudocysts. The researchers first used a 19G EUS puncture needle to puncture into the cyst through the gastric or duodenal wall. After the balloon was dilated to form a appropriately sized channel, a matching catheter was inserted and a stent was placed. The treatment effect was evaluated based on the patient's symptom relief and changes in cyst diameter.