Objective To evaluate changes of local flow field following implantation of a designed iliac venous stent. Methods Anin vitro physical model with iliocava junction was established. A modified iliac venous stent was implanted into one side and a conventional stent into the other side. The bilateral local flow fileds following implantation of stents were measured by using particle image velocimetry. Results The results of particle image velocimetry testing revealed that the main flow orientation was shifted to the right side and the region of slowly local flow was observed after implantation of conventional iliac venous stent. However, no evident changes were noted in the local flow field and no whirling flow was detected following implantation of the designed iliac venous stent. Conclusion Conventional stent is implanted into iliac vein by using a traditional technique and stent is proximal to heart and covers opening of contralateral iliac vein, which exerts certain influence upon local flow field. Local flow field has no obvious change following implantation of a designed iliac venous stent.
ObjectiveTo observe the efficacy of restrictive bare stent released on the distal end of the trunk of Stanford type A aortic dissection. Methods The clinical data of 22 patients with Stanford type A aortic dissection requiring aortic arch replacement and trunk surgery and selected for restrictive bare stent placement from November 2016 to February 2018 in our hospital were retrospectively analyzed. Among them, there were 19 males and 3 females, aged 34-68 (49.72±8.05) years. The bare stent was released in the descending thoracic aorta, and the stented elephant trunk was placed in the bare stent. The aortic computerized tomography angiography was reviewed before discharge and the stent position and complications were observed. ResultsOne patient failed to be implanted with bare stents due to a greater resistance and prolapse during implantation. Bare stents were successfully implanted in the remaining 21 patients. One patient died of large-area cerebral infarction after surgery and one patient suffered paraplegia. Twenty patients who survived and successfully implanted bare stents were followed up at regular intervals for 4-21 (13.00±6.14) months. No stroke or death occurred during the follow-up. The computerized tomography angiography showed good stent morphology and position, and no displacement or type Ⅲ endoleak. No stent graft-induced new entry was found. ConclusionAs an adjunct to stented elephant trunk, the use of restrictive bare stents can reduce the possibility of recurrence of a distal stent fracture, significantly expand the narrowest segment and true lumen caliber near the endoluminal graft. Aortic remodeling works well.
ObjectiveTo investigate treatment methods and effect of endovascular interventional therapy for visceral artery aneurysms.MethodsThe clinical data of 32 patients with visceral artery aneurysms, who were treated in the No. 960 Hospital of PLA from February 2011 to April 2018, were retrospectively analyzed. It was proveded by the CT or digital subtraction angiography before the interventional therapy. The implantation of covered stent, coil embolization together with stent implantation, double stents placement or pure coil embolization were performed. The postoperative antithrombotic therapy was adopted in the patients accepted the stent implantation. The CT angiography was performed on the month of 1, 6, 12, 24 or the patient was uncomfortable after the treatment to evaluate the obstruction condition of the aneurysms, stent blood flow, and branches arteries, etc..ResultsThe success rate of the endovascular interventional therapy was 100%. In the 11 patients underwent the implantation of covered stent, the postoperative angiography showed that the stent lumen was patent and the aneurysm was not visualized. In the 9 patients underwent the coil embolization together with stent implantation and 3 patients underwent the double stents placement, the postoperative angiography results of the aneurysm showed that it was faintly visualized and the branch arteries were not involved. In the 9 patients underwent the pure coil embolization, the postoperative angiography showed that the aneurysm was not visualized. No perioperative mortality or procedure related complications occurred. No case was lost during the follow-up of a median period of 25.5 (6–48) months. During the follow-up, one patient developed the mild abdominal pain in one month, which disappeared after the symptomatic medication management. Except for 1 patient developed the mild stent stenosis (<30%) on the 12th month after the procedure, the stent and the branch arteries of the other patients were completely patent, and no aneurysms recurred.ConclusionFor treatment of visceral artery aneurysms, endovascular interventional therapy is safe and effective and shows an excellent short-term and mid-term effects.