Development of self-expandable covered stents

Endovascular treatment of post-pharyngitis internal carotid artery pseudoaneurysm with a covered stent in a child: a case report

CASE REPORT

We report a case of 4-year-old boy patient, who developed after a streptococcal pharyngitis a painful, pulsatile, and growing right-sided mass in the neck. Imaging studies revealed an extracranial right internal carotid artery pseudoaneurysm. The patient was successfully treated with stent-graft deployment. After 18 months of follow-up, the pseudoaneurysm is excluded from the circulation, the carotid artery is patent, and the patient is free from any neurological deficit.

DISCUSSION

Covered stents might be considered as a valid therapeutic option to treat carotid artery pseudoaneurysms.

Functional design of porous drug delivery systems based on laser assisted manufactured nitinol

Our previous studies proved the occurrence of the shape memory effect (SME) in a biocompatible porous nitinol (inter-metallic phase NiTi), obtained by the selective laser sintering (SLS) method. In this report we propose to use the SME peculiar to the nitinol, for a functional design of the drug delivery system and to discuss the process flow pattern. In living tissues (flesh) the elevated temperature at the disease origination leads to the nitinol pores size reduction caused by the austenite phase transformation, and to the pharmaceutical composition extrusion from the pores. And vice versa, during the cooling stage when the tissue temperature reverts to normal level, the drug intake will stop. Depending on the type of the three dimensional structure of a porous matrix (scaffold) identified at the stage of a computer-aid-design, the velocity of penetration can be controllable.

Autologous small-caliber "biotube" vascular grafts with argatroban loading: a histomorphological examination after implantation to rabbits

Functional autologous tubular tissues, termed "biotubes," have been developed as small-caliber vascular grafts. Biotubes can be easily and safely constructed in vivo by using a novel concept in regenerative medicine-in body tissue architecture technology, which requires neither clean specialized laboratories nor complex cell management. Biotubes with "anastomotic reinforcement cuffs" were prepared by embedding a silicone rod (diameter, 3 mm; length, 30 mm) as a mold in the dorsal subcutaneous pouches of rabbits. The rod was covered at both ends with 2 pieces of polyurethane sponge tubes (length, 3 mm), and it was removed when the grafts were harvested. These biotubes had homogeneous thin connective tissue walls (thickness: 76 +/- 37 microm) that were primarily composed of collagen and fibroblasts. The resulting cuff-impregnated biotubes were auto-implanted in the carotid arteries for predetermined periods of up to 12 weeks and then morphologically examined. On implantation of the biotubes after argatroban loading, the total patency was 9/11 without any instance of aneurysm formation or rupture. At 12 weeks after implantation, no significant neointimal thickening was observed (170 +/- 30 microm). In addition, minimal thrombus formation was observed on the luminal surfaces, which were completely covered with endothelial cells regularly oriented longitudinally. The regenerated vascular walls comprised multilayered smooth muscle cells and dense collagen fibers with regular circumferential orientation with few elastin fibers and were similar to native arteries. Biotubes with argatroban loading could thus be used as small-caliber vascular prostheses that greatly facilitate healing process and exhibit excellent biocompatibility.

Stent-graft repair of a large cervical internal carotid artery pseudoaneurysm causing dysphagia

Pseudoaneurysms of the cervical internal carotid artery (ICA) are rare and most frequently result from trauma, infection, or sometimes spontaneously. They have the potential to cause life-threatening hemorrhage; thus, their immediate management is necessary. Endovascular treatment by stent graft placement in the affected artery appears to be a safe and effective treatment option. We present a case of a child who presented with neck swelling and dysphagia caused by a ruptured cervical ICA pseudoaneurysm which was managed by stent graft placement.