[Comparison of stent displacement and displacement force after endovascular aneurysm repair with cross-limb or parallel-limb stent]

This study aims to investigate whether displacement force on stents can accurately represents the displacement of the stent after endovascular aneurysm repair (EVAR) by comparing the measured stent displacement with the displacement forces calculated by computational fluid dynamics (CFD). And the effect of cross-limb and parallel-limb EVAR on stent displacements is further studied. Based on our objective, in this study, ten cross-limb EVAR patients and ten parallel-limb EVAR patients in West China Hospital of Sichuan University were enrolled. Patient-specific models were first reconstructed based on the computed tomography angiography images, then the stent displacements were measured, and the displacement forces acting on the stents were calculated by CFD. Finally, the c o s α value of the angle between the displacement force and the displacement vector was used to analyze the matching degree between the displacement and the displacement force. The results showed that the displacement forces on cross-limb stents and parallel-limb stents were (2.67 ± 2.14) N and (1.36 ± 0.48) N, respectively. Displacements of stent gravity center, stent displacements relative to vessel, and vessel displacements of cross-limb and parallel-limb stents were (4.43 ± 2.81) mm and (6.39 ± 2.62) mm, (0.88 ± 0.67) mm and (1.11 ± 0.71) mm, (3.55 ± 2.88) mm and (5.28 ± 2.52) mm, respectively. The mean c o s α for cross-limb and parallel-limb stents were 0.02 ± 0.66 and - 0.10 ± 0.73, respectively. This study indicates that the displacement force on the stent can't accurately represent the displacement of the stent after EVAR. In addition, the cross-limb EVAR is probably safer and more stable than the parallel-limb EVAR.

Double anchor lock fixing method to prevent stent displacement in endoscopic ultrasound-guided gastroenterostomy: a porcine study

BACKGROUND

Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is widely used in patients with gastric outlet obstruction (GOO). Recurrence of obstruction symptoms caused by stent migration is the major reason for reintervention in EUS-GE. To solve this problem, we proposed developing a double anchor lock (DAL) fixing stent method for EUS-GE. The safety and efficacy of the DAL fixing stent method were evaluated in this study.

METHODS

Sixteen Bama miniature pigs were randomly divided into an experimental group (n = 8) and a control group (n = 8). A gastric outlet obstruction model was established for all the pigs. The experimental group was treated with the DAL fixing stent method for EUS-GE, while the control group was treated with EUS-GE. Three-month stent migration rate, remission rate of GOO, re-occlusion intervention rate, weight change, and incidence of procedure-related complications of EUS-GE were analyzed and estimated in the two groups.

RESULTS

EUS-GE was successfully completed in every subject in both groups. Symptoms of digestive tract obstruction can be relieved in all animals. The stent existence rate in the 3 months was higher in the experimental group than in the control group (87.5% vs. 12.5%, P = 0.012). Except for one animal in the experimental group in which there was pneumoperitoneum due to a stent insertion failure, no animal experienced bleeding or perforation.

CONCLUSION

The DAL fixing stent method, which can effectively prevent stent migration, is safe and simple. EUS-GE can effectively relieve the symptoms of digestive tract obstruction.

Stent displacement in endoscopic pancreatic pseudocyst drainage and endoscopic management

A pancreatic pseudocyst (PPC) is a collection of pancreatic fluid enclosed by a non-epithelialized, fibrous or granulomatous wall. Endoscopic pancreatic pseudocyst drainage (PPD) has been widely used clinically to treat PPCs. The success and complications of endoscopic PPD are comparable with surgical interventions. Stent displacement is a rare complication after endoscopic PPD. Almost all the complications of endoscopic PPD have been managed surgically, and there is rare report involving the endoscopic treatment of intraperitoneal stent displacement. We report here a case of stent displacement after endoscopic ultrasound- and fluoroscopy-guided PPD in a 41-year-old female patient with a PPC in the tail of the pancreas. The endoscopic treatment was successfully performed to remove the displaced stent. The clinical course of the patient was unremarkable. The cyst had significantly reduced and disappeared by 12 wk. We found that both endoscopic ultrasound and fluoroscopy should be used during endoscopic PPD to avoid stent displacement. The displaced stent can be successfully treated by endoscopic removal.