nitinol and Endoleak

A 71-year old man with previous thoracic aneurysm endovascular repair and endovascular abdominal aneurysm repair presented with simultaneous type III endoleak from the thoracic components and type Ia endoleak from migration of the abdominal endograft, leading to enlargement of both aneurysms. A custom-made reverse tapered Relay NBS thoracic endograft was used to bridge the thoracic stent grafts. While a low-flow type III endoleak persisted in the immediate postoperative phase, because of incomplete apposition of the new stent graft, further deployment of its nitinol skeleton resulted in resolution of the endoleak at 1-week follow-up. The abdominal aneurysm enlargement was corrected via excision of the central segment of the abdominal endograft, preservation of the distal main body and limbs, and interposition of a short Dacron tube graft.

Topics: Aged; Alloys; Aortic Aneurysm, Abdominal; Aortic Aneurysm, Thoracic; Aortography; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Computed Tomography Angiography; Endoleak; Endovascular Procedures; Foreign-Body Migration; Humans; Male; Polyethylene Terephthalates; Prosthesis Design; Prosthesis Failure; Stents; Treatment Outcome

The ideal stent combination for chimney endovascular aneurysm repair remains undetermined. Therefore, we sought to identify optimal aortic and chimney stent combinations that are associated with the best outcomes by analyzing the worldwide collected experience in the PERformance of chImney technique for the treatment of Complex aortic pathoLogiES (PERICLES) registry.. The PERICLES registry was reviewed for patients with pararenal aortic disease electively treated from 2008 to 2014. Eleven different aortic devices were identified with three distinct subgroups: group A (n = 224), nitinol/polyester; group B (n = 105), stainless steel/polyester; and group C (n = 69), nitinol/expanded polytetrafluoroethylene. The various chimney stent subtypes included the balloon-expandable covered stent (BECS), self-expanding covered stent, and bare-metal stent. Deidentified aortic and chimney device combinations were compared for risk of chimney occlusion, type IA endoleak, and survival. Effects of high-volume centers (>100 cases), use of an internal lining chimney stent, number of chimney stents, and number of chimney stent subtypes deployed were also considered. We considered demographics, comorbidities, and aortic anatomic features as potential confounders in all models.. The 1- and 3-year freedom from BECS chimney occlusion was not different between groups (group A, 96% ± 2% and 87% ± 5%; groups B and C, 93% ± 3% and 76% ± 10%; Cox model, P = .33). Similarly, when non-BECS chimney stents were used, no difference in occlusion risk was noted for the three aortic device groupings; however, group C patients receiving BECS did have a trend toward higher occlusion risk relative to group C patients not receiving a BECS chimney stent (hazard ratio [HR], 4.0; 95% confidence interval [CI], 0.85-18.84; P = .08). Patients receiving multiple chimney stents, irrespective of stent subtype, had a 1.8-fold increased risk of occlusion for each additional stent (HR, 1.8; 95% CI, 1.2-2.9; P = .01). Use of a bare-metal endolining stent doubled the occlusion hazard (HR, 2.1; 95% CI, 1.0-4.5; P = .05). Risk of type IA endoleak (intraoperatively and postoperatively) did not significantly differ for the aortic devices with BECS use; however, group C patients had higher risk relative to groups A/B without BECS (C vs B: odds ratio [OR], 3.2 [95% CI, 1-11; P = .05]; C vs A/B: OR, 2.4 [95% CI, 0.9-6.4; P = .08]). Patients treated at high-volume centers had significantly lower odds for development of type IA endoleak (OR, 0.2; 95% CI, 0.1-0.7; P = .01) irrespective of aortic or chimney device combination. Mortality risk was significantly higher in group C + BECS vs group A + BECS (HR, 5.3; 95% CI, 1.6-17.5; P = .006). The 1- and 3-year survival for groups A, B, and C (+BECS) was as follows: group A, 97% ± 1% and 92% ± 3%; group B, 93% ± 3% and 83% ± 7%; and group C, 84% ± 7% and 63% ± 14%. Use of more than one chimney subtype was associated with increased mortality (HR, 3.2; 95% CI, 1.4-7.5; P = .006).. Within the PERICLES registry, use of nitinol/polyester stent graft devices with BECS during chimney endovascular aneurysm repair is associated with improved survival compared with other aortic endografts. However, this advantage was not observed for non-BECS repairs. Repairs incorporating multiple chimney subtypes were also associated with increased mortality risk. Importantly, increasing chimney stent number and bare-metal endolining stents increase chimney occlusion risk, whereas patients treated at low-volume centers have higher risk of type IA endoleak.

Topics: Aged; Aged, 80 and over; Alloys; Aortic Aneurysm, Abdominal; Aortic Aneurysm, Thoracic; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Comorbidity; Disease-Free Survival; Endoleak; Endovascular Procedures; Europe; Female; Graft Occlusion, Vascular; Hospitals, High-Volume; Hospitals, Low-Volume; Humans; Male; Multivariate Analysis; Odds Ratio; Polyesters; Polytetrafluoroethylene; Proportional Hazards Models; Prosthesis Design; Registries; Retrospective Studies; Risk Factors; Stainless Steel; Stents; Time Factors; Treatment Outcome; United States

Topics: Alloys; Endoleak; Humans; Stents; Treatment Outcome

To report an unsuccessful use of large nitinol stent to prevent proximal endoleak in endograft treatment for juxtarenal aortic aneurysm.. An 82-year-old male presented coronary disease and severe chronic obstructive pulmonary disease requiring oxygen support. A large 80-mm juxtarenal aneurysm was found on routine urological examination. Neck features were as follows: 7 mm and high anterior-posterior angulation. ASA risk score IV was given. Patient wanted to be treated. We decided a 1-shot intervention based on self-expandable suprarenal fixation endograft with adjunctive extra large self-expandable (high radial force) nitinol stent. Control computed tomography scan demonstrates nitinol stent severe infolding and a possible perforation of the primary endograft. At 6-month follow-up, sac reveals enlargement of 5 mm and 6% volume increase. Patient does not want further treatments due to high risk of procedures.. Extreme caution should be taken when using self-expandable extra large nitinol stents for preventive matters. Oversizing should be carefully considered, not necessarily reaching the endograft chosen size. When short and angulated neck morphology co-exists, other devices or procedures may be a better option.

Topics: Alloys; Aortic Aneurysm, Abdominal; Aortography; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Computed Tomography Angiography; Endoleak; Endovascular Procedures; Humans; Prosthesis Design; Prosthesis Failure; Self Expandable Metallic Stents; Treatment Outcome

We report a preliminary experience about endovascular aortic repair (EVAR) of infrarenal abdominal aortic aneurysm (iAAA) with severe proximal aortic neck angulation (NA) using the Aorfix™ stent graft.. Data of consecutive patients with iAAA with severe proximal NA submitted to endovascular repair between September 2012 and December 2014 in 2 Italian centers of Vascular and Endovascular Surgery were retrospectively reviewed, and outcomes were analyzed using the software JMP 5.1.2.. A total of 26 patients were treated. Median proximal NA was 87.5° (range 68-108°), and 3 patients were treated outside the instruction for use of Aorfix because of a proximal NA > 90°. Eleven patients (42.3%) had severe iliac tortuosity. The primary success rate was 92.3%, as 2 patients required intraoperative correction of a type Ia endoleak. Within 30 days, a right limb occlusion was successfully resolved with endovascular recanalization. The median follow-up period was 14 months (range 1-48 months): 1 patient died for neoplasm and 1 patient presented a type II endoleak from lumbar arteries at 3 months, which is still under surveillance. No other complications were reported during the follow-up period.. Preliminary results with the Aorfix stent graft seemed to be promising in the aim of reducing endoleak and migration rates in presence of iAAA with severe proximal aortic NA.

Topics: Aged; Alloys; Aortic Aneurysm, Abdominal; Aortography; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Computed Tomography Angiography; Endoleak; Endovascular Procedures; Female; Foreign-Body Migration; Humans; Italy; Male; Preliminary Data; Prosthesis Design; Retrospective Studies; Stents; Time Factors; Treatment Outcome

The frozen elephant procedure, as a hybrid method to treat aortic pathologies involving the aortic arch and the proximal descending aorta, has become an accepted treatment option. We report two late fractures of the nitinol stents of the endograft of an early frozen elephant trunk prosthesis. One patient suffered from a tear of the woven polyester fabric, causing a Type III endoleak and rapid progression of the existing descending aortic aneurysm. The patient received replacement of the descending aorta. The second patient showed a fracture of a nitinol stent without further complications during follow-up.

Topics: Alloys; Aortic Aneurysm, Thoracic; Aortic Dissection; Blood Vessel Prosthesis Implantation; Computed Tomography Angiography; Endoleak; Humans; Prosthesis Design; Prosthesis Failure; Stents

To report the bench-top evaluation and initial clinical use of an instrument for on-site fenestration of aortic stent-grafts.. A stainless steel thermal cautery instrument was designed to create circular stent-graft fenestrations from 3 to 10 mm in diameter. Three operators independently bench-tested the instrument on thoracic stent-graft samples to evaluate size, shape, location, and quality of fenestrations created. For clinical use, on-site fenestration was performed 2 days before the endovascular procedure in a sterile room without access to supplemental oxygen. A fenestrator 1 or 2 mm smaller in diameter than the target vessel was used; the edges of the fenestrations were strengthened using flexible radiopaque nitinol wire. The aortic stent-graft was then re-sheathed and sterilized for added safety. Eighteen patients (17 men; mean age 51 years, range 18-80) with a variety of thoracic and juxtarenal pathologies were treated using Zenith TX2, Valiant Captivia, Zenith AAA, and Endurant stent-grafts modified in this manner.. After successful bench testing, the instrument was used to create 34 fenestrations in aortic stent-grafts deployed in the 18 patients. Size and location of fenestrations obtained were as desired. Subsequent catheterization of the fenestration/target vessel and covered stent deployment were successfully achieved in 31 (91%) fenestrations; 2 fenestrations had type III endoleaks and 1 fenestration was unused. There was no perioperative mortality, stroke, embolization, vessel dissection, renal failure, or graft infection. Follow-up to 1 year in the majority of patients has revealed no new fenestration-related problems.. This simple-to-use instrument makes on-site creation of aortic stent-graft fenestrations easy, accurate, and precise. The instrument is inexpensive, robust, and easily sterilized.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Alloys; Aorta, Abdominal; Aorta, Thoracic; Aortic Diseases; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Cautery; Endoleak; Endovascular Procedures; Equipment Design; Feasibility Studies; Female; Humans; Male; Materials Testing; Middle Aged; Prosthesis Design; Stainless Steel; Stents; Time Factors; Treatment Outcome; Young Adult

Treatment of endoleaks after thoracic endovascular repair remains challenging, particularly when the proximal landing zone is small and partly includes the origin of the neck vessels. We report a Type Ia endoleak, occurring after thoracic endovascular aneurysm repair, which was successfully treated with a novel uncovered nitinol stent. With this success, we were able to avoid a conventional surgery to treat the endoleak.

Topics: Aged; Alloys; Aortic Aneurysm, Thoracic; Aortography; Blood Vessel Prosthesis Implantation; Endoleak; Endovascular Procedures; Humans; Male; Prosthesis Design; Reoperation; Stents; Tomography, X-Ray Computed; Treatment Outcome

During endovascular abdominal aortic aneurysm repair, a severely angulated neck can make proximal sealing of endografts challenging, and the occurrence of a type Ia endoleak can complicate the procedure. We describe an original adjunctive procedure involving transrenal placement of a self-expanding nitinol stent (E-XL aortic stent; Jotec GmbH, Hechingen, Germany) to remodel the proximal aortic neck and treat or prevent type Ia endoleaks in the case of severe angulation of the proximal neck.

Topics: Aged; Aged, 80 and over; Alloys; Aortic Aneurysm, Abdominal; Aortography; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Endoleak; Endovascular Procedures; Female; Humans; Male; Prosthesis Design; Stents; Tomography, X-Ray Computed; Treatment Outcome

Thoracic endovascular aortic repair is increasingly becoming the standard treatment of many thoracic aortic pathologies. New reliable and accurate stent grafts are emerging to widen the endovascular treatment options. We report the results of RELAY (Bolton Medical, Barcelona, Spain) in the large RELAY Endovascular Registry for Thoracic Disease (RESTORE) European registry.. RESTORE is a multicenter, prospective European registry involving 22 centers in seven European countries. The RELAY device is composed of a stent graft (self-expanding nitinol stents and a polyester vascular graft) and a delivery device specifically designed for the thoracic aorta. Included were acute and elective patients presenting with a variety of pathologies (aneurysms, dissections, ulcerations, intramural hematomas, pseudoaneurysms) and lesions in different aortic and anatomic locations (ascending, arch, descending and thoracoabdominal).. The registry enrolled 304 patients from April 2005 to January 2009. All-cause mortality at 30 days was 7.2%. Freedom from all cause mortality and freedom from device- and procedure-related mortality at 2 years were 78.5% and 95.9%, respectively. An average of 1.26 graft components were used per patient, with a technical success of 97.7% irrespective of the etiology. Early endoleak rate was 4.6%. Perioperatively, stroke and paraplegia were registered in 1.6% and 2.0%, respectively.. The results of RESTORE support the safety of thoracic endovascular aortic repair with the RELAY stent graft, even in acute and complicated situations. The device was highly efficient in angulated aortic anatomies, with acceptable mortality and a low rate of neurologic complications.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Alloys; Aorta, Thoracic; Aortic Diseases; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Endoleak; Endovascular Procedures; Europe; Female; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Paraplegia; Polyesters; Prospective Studies; Prosthesis Design; Registries; Risk Assessment; Stents; Stroke; Time Factors; Treatment Outcome; Young Adult