Endovascular Aneurysm Repair and Sealing (EVARS): A Useful Adjunct in Treating Challenging Morphology.

An 81-year-old male with previous open abdominal aortic aneurysm repair presented with asymptomatic large pseudoaneurysms at both ends of an open surgical tube graft. Endovascular aneurysm sealing (EVAS) in combination with the iliac limbs of a standard endovascular aneurysm repair (EVAR) successfully excluded both pseudoaneurysms from circulation. We describe the combination of elements of EVAS and EVAR and have termed this endovascular aneurysm repair and sealing (EVARS). EVARS has the advantage of harnessing the benefits of endobag sealing in aortic necks unsuitable for standard EVAR whilst providing the security of accurate stent placement within short common iliac arteries. In conclusion, EVAS may be combined with standard endovascular iliac limbs and is a possible treatment option for pseudoaneurysm following open aneurysm repair.

Aortic Dehiscence During Endovascular Sealing for Ruptured Abdominal Aortic Aneurysms.

PURPOSE: To present a case of aneurysm disruption during endovascular sealing of a ruptured abdominal aortic aneurysm. CASE REPORT: A 91-year-old woman presented with a ruptured abdominal aortic aneurysm. Her aneurysm morphology was unsuitable for standard or fenestrated endovascular repair, whereas open repair was considered to have an increased perioperative risk owing to multiple comorbidities. The Nellix endovascular sealing system was used. The balloon-expandable stent-grafts were deployed, but in the presence of aneurysm rupture, it was decided not to prefill the endobags with saline. The patient developed hypotension during endobag filling, which resolved once target pressure was reached. The procedure was completed uneventfully, and the completion angiogram revealed no endoleak. The time from guidewire insertion to completion angiogram was 24 minutes. Over the following days, she developed a gradual drop in hemoglobin, and computed tomographic angiography revealed an increased retroperitoneal hematoma and pronounced disruption of the calcified rim of the aortic sac compared to the preoperative imaging. She was managed with supportive treatment, demonstrating remarkable progress. She remains in good health 4 months later. CONCLUSION: Endovascular sealing can be used in patients with ruptured abdominal aortic aneurysm. Intraoperative endobag saline prefill should be avoided to minimize the risk of aortic wall disruption.

Closure technique after carotid endarterectomy influences local hemodynamics.

BACKGROUND: Meta-analysis supports patch angioplasty after carotid endarterectomy (CEA); however, studies indicate considerable variation in practice. The hemodynamic effect of a patch is unclear and this study attempted to elucidate this and guide patch width selection. METHODS: Four groups were selected: healthy volunteers and patients undergoing CEA with primary closure, trimmed patch (5 mm), or 8-mm patch angioplasty. Computer-generated three-dimensional models of carotid bifurcations were produced from transverse ultrasound images recorded at 1-mm intervals. Rapid prototyping generated models for flow visualization studies. Computational fluid dynamic studies were performed for each model and validated by flow visualization. Mean wall shear stress (WSS) and oscillatory shear index (OSI) maps were created for each model using pulsatile inflow at 300 mL/min. WSS of <0.4 Pa and OSI >0.3 were considered pathological, predisposing to accretion of intimal hyperplasia. The resultant WSS and OSI maps were compared. RESULTS: The four groups comprised 8 normal carotid arteries, 6 primary closures, 6 trimmed patches, and seven 8-mm patches. Flow visualization identified flow separation and recirculation at the bifurcation increased with a patch and was related to the patch width. Computational fluid dynamic identified that primary closure had the fewest areas of low WSS or elevated OSI but did have mild common carotid artery stenoses at the proximal arteriotomy that caused turbulence. Trimmed patches had more regions of abnormal WSS and OSI at the bifurcation, but 8-mm patches had the largest areas of deleteriously low WSS and high OSI. Qualitative comparison among the four groups confirmed that incorporation of a patch increased areas of low WSS and high OSI at the bifurcation and that this was related to patch width. CONCLUSIONS: Closure technique after CEA influences the hemodynamic profile. Patching does not appear to generate favorable flow dynamics. However, a trimmed 5-mm patch may offer hemodynamic benefits over an 8-mm patch and may be the preferred option.

Guidewire stiffness: what's in a name?

PURPOSE: To measure the stiffness of commonly used "stiff" guidewires in terms of their flexural modulus, an engineering parameter related to bending stiffness. METHODS: Eleven different intact stiff guidewires were selected to undergo a 3-point bending test performed using a tensile testing machine. Testing was performed on 3 new and intact specimens of each guidewire at 10 locations along the wire's length, excluding the floppy tip. The flexural modulus (in gigapascals, GPa) was calculated from the results of the bending test. RESULTS: The flexural modulus of the plain Amplatz wire was 9.5 GPa compared to 11.4 to 14.5 GPa for the "heavy duty" wires. Within the Amplatz family of guidewires, the flexural modulus was 17 GPa for the "stiff," 29.2 GPa for the "extra stiff," 60.3 GPa for the "super stiff," and 65.4 GPa for the "ultra stiff." The Backup Meier measured 139.6 GPa and the Lunderquist Extra Stiff 158.4 GPa. CONCLUSION: The Instructions for Use of some endovascular devices specify a wire type selected from a range of undefined "stiffness" descriptors. These descriptors have little correlation with the measured flexural modulus. Two guidewires with the description "extra stiff" can have a 5-fold difference in flexural modulus. We recommend that guidewire catalogues and packaging include the flexural modulus and that device manufacturers amend their Instructions for Use accordingly.