Matteus A.M. Linsen

Carotid Artery Dynamics during Head Movements: A Reason for Concern with Regard to Carotid Stenting?

Purpose: To evaluate carotid artery mobility patterns during head movements following carotid angioplasty/stenting (CAS). Methods: In 7 patients (all men; mean age 69 years, range 65–76) who had undergone unilateral CAS, 3D time-of-flight magnetic resonance angiography was performed, visualizing both carotid arteries in 5 different head positions (neutral, turned left and right, and bent forward and backward). Maximum intensity projection reconstructions were obtained to measure angulation at the proximal and distal stent junction. Configuration changes of the stented section of the carotid artery and the unstented contralateral artery were judged. Secondly, transverse sections at the level of the carotid bifurcation and at the skull base were used to calculate torsion shear in the common and internal carotid arteries (CCA, ICA) during turned left and right head position. Results were expressed as median (range). Results: In neutral head position, maximal angulation at the distal stent junction was 34.3° (32.3°–55.6°). With the head bent forward, this angulation changed to 47.6° (42.6°–85.2°, p=0.028) and when bent backward to 26.5° (25.0°–48.7°, p=0.027). In all patients, configuration changes of the stented sections were absent. The contralateral unstented side showed diffuse configuration changes without specific angulation at one location. With the head turned left and right, the CCA on the stented side was subjected to 28.6° (13.6°–53.7°) and 24.9° (2.0°–50.6°) of torsion shear, respectively. Torsion of the ICA was subsequently 18.1° (12.7°–40.5°) and 15.2° (2.9°–69.4°). Conclusions: Following carotid stenting, sharp ICA angulations that are aggravated by forward bending of the head occur at the distal stent junction. The stented section of the carotid artery shows complete lack of flexibility despite highly flexible features of the stents ex vivo. Both the CCA and ICA are subjected to considerable torsion shear with the head turned left and right. This shear is not accommodated by the current stent designs.

Suture damage during robot-assisted vascular surgery: is it an issue?

Background Manipulation of sutures during endoscopic surgery could lead to damage of suture structure, supposedly resulting in loss of strength. Lack of tactile feedback in robotic surgical systems might increase this problem. The objective of this study is to evaluate suture strength after robotic manipulation and to determine which suture material is least susceptible to damage from robotic manipulation. Methods The da Vinci surgical system was used to manipulate sutures. Three different suture materials (Prolene, ePTFE, Ethibond) of 3 different sizes (3-0, 4-0, and 5-0) were tested. A total of 270 sutures were pulled on a Servohydraulic Universal Testing Machine. The frequency of breaks at a manipulation-point and the maximum applied force (N) before the suture broke were used for statistic analysis. Results No loss in strength was shown in the ePTFE sutures after manipulation, whereas both Prolene and Ethibond sutures showed a significant loss of strength. Conclusions ePTFE sutures are least susceptible to robotic manipulations and are, therefore, to be considered as a material of first choice.

Modular Branched Endograft System for Aortic Aneurysm Repair: Evaluation in a Human Cadaver Circulation Model:

A circulation model was created in 6 nonaneurysmal human cadavers to evaluate the deliverability, deployment, and acute performance of a modular branched endograft system for treatment of aortic aneurysms containing essential branch vessels. Two fenestrations were created in an appropriately sized aortic main endograft. Under fluoroscopic guidance, the main endograft was advanced to the target site and the fenestrations were aligned with the ostia of the renal arteries. Branch grafts were placed through the fenestrations into the renal arteries. The outcome was evaluated by post implant angiography and autopsy. Eleven branch grafts were deployed at the target site. All targeted renal arteries showed good patency. At autopsy, all main endografts were adequately deployed, and 10 of 11 branch grafts were locked in place. In this model, deliverability and deployment of the modular branch graft system is feasible in a reliable, predictable, and timely fashion.

Aortoiliac steno-occlusion in young women: a single center experience and review of the literature.

Abstract Peripheral obliterating arterial disease characterized by aortoiliac steno-occlusion occurring in relatively young women of small stature, is frequently reported in the literature under the name small aorta syndrome. Although it remains unclear whether small aorta syndrome represents a separate entity, the small size of the distal aorta increases risk for aortoiliac occlusive disease. Patients usually present with lower extremity claudication and typical risk factors. This paper shows an analysis of the literature focusing on the pathogenesis, clinical features, risk factors and treatment, as well as a single center experience with this disorder.

A Temporary Hemostatic Valve in the Short Limb of a Bifurcated Stent-Graft to Facilitate Endovascular Repair of Ruptured Aortic Aneurysm: Experimental Findings:

Purpose: To evaluate a homemade tricuspid valve placed in the short limb of a bifurcated aortic stent-graft to facilitate endovascular treatment of ruptured abdominal aortic aneurysms (AAA). Methods: A valve consisting of 3 polytetrafluoroethylene cusps was constructed in the short limb of a bifurcated stent-graft. The endoprosthesis was placed into an in vitro circulation model with pulsatile flow. Angiography was performed before and after insertion of the second graft limb. Results: Angiographically, there was complete occlusion of the short limb before and normal patency after deployment of the second graft limb. Cannulation of the short limb with a guidewire was performed without technical difficulty. Conclusions: Addition of a temporary hemostatic valve in the short limb of a bifurcated stent-graft can potentially reduce blood loss during endovascular treatment of ruptured AAAs.