Stent-Graft Placement in Atherosclerotic Descending Thoracic Aortic Aneurysms: Midterm Results

Purpose:

To determine midterm durability and need for reinterventions after stent-graft placement in atherosclerotic descending thoracic aortic aneurysms.

Methods:

Fifty-four patients (38 men; mean age 68 years, range 33–87) underwent stent-graft repair of chronic atherosclerotic aneurysms of the descending thoracic aorta between November 1996 and December 2002. Acute aortic syndromes (type B aortic dissections, perforating ulcers, and traumatic dissections) were excluded from analysis. Two types of commercially available stent-grafts were used (Talent and Excluder).

Results:

The primary technical success rate was 94.4%. In-hospital mortality was 3.7% (2/54). No adverse neurological events were encountered. Of 3 (5.6%) early type I endoleaks, 2 (3.7%) required reintervention; the other type I endoleak closed spontaneously. Mean follow-up was 38 months (range 1–72) in the 52 surviving patients. Four (7.7%) type I, 7 (13.5%) type II, and 4 (7.7%) type III endoleaks were seen. Three 3 patients had additional treatment for endoleaks (proximal stenting [type Ia], open thoracoabdominal repair [type Ib], and embolization [type II]). Two of the 3 reinterventions were performed in the first year of follow-up. One additional patient with a type Ia endoleak not suitable for reintervention is under close observation. There were no differences in the number of endoleaks between the 2 types of stent-grafts. Three-year event-free survival was 63%.

Conclusions:

Midterm durability of endovascular stent-graft placement in atherosclerotic descending aortic aneurysms seems promising, as the rate of endoleaks requiring reintervention is acceptably low. In our series, endoleak formation occurred during the first year after stent-graft placement, so close follow-up of patients after aortic aneurysm repair is crucial. Further studies are warranted to evaluate long-term durability of this new treatment modality.

Intraoperative Intrasac Thrombin Injection to Prevent Type II Endoleak after Endovascular Abdominal Aortic Aneurysm Repair

Purpose:

To report a prospective, nonrandomized pilot study to determine whether fibrin glue aneurysm sac embolization at the time of endovascular aneurysm repair (EVAR) is a safe and effective procedure to primarily prevent type II endoleaks.

Methods:

Between June 2003 and December 2005, 84 consecutive patients (79 men; mean age 73.8±7.8 years, range 64–86) with degenerative infrarenal abdominal aortic aneurysm underwent EVAR with bifurcated stent-grafts and fibrin glue injection into the aneurysm sac at the conclusion of the endovascular procedure. A total of 424 imaging studies and 348 visits were recorded during the study period and reviewed.

Results:

Selective catheterization of the aneurysm sac and fibrin glue injection immediately after initial stent-graft deployment was successful in 83 (99%) of 84 cases; there was one failure to access the excluded aneurysm sac due to severe iliac artery calcification. The estimated primary and assisted clinical success rates at 2 years were 91.3% and 98.8%, respectively, but the major findings were the low rate of delayed type II endoleak (2.4%) and the statistically significant decrease in the maximum transverse aneurysm diameter (50.40±6.70 versus 42.03±6.50 mm, p=0.0001) at follow-up. In addition, of 31 patients available for 24-month follow-up, 14 (45.2%) patients showed a reduction in maximum transverse aneurysm diameter by ≥5 mm; 16 (51.6%) patients had no significant changes, whereas only 1 patient showed a >5-mm enlargement.

Conclusion:

This clot engineering approach to aneurysm sac embolization at the time of endografting appears to be safe and may spare the patient a repeated catheter-based intervention or surgical procedure.

Models of abdominal aortic aneurysm: characterization and clinical applications

Abdominal aortic aneurysms (AAAs) are responsible for considerable morbidity, mortality, and cost to society. The pathogenesis of AAA formation, however, remains poorly understood. Animal models have been used in a range of experiments designed to provide further objective scientific assessment of the pathogenesis as well as the treatment of AAA. The purpose of this manuscript is to review the current models of AAA and their potential clinical implications.

Fibrin Glue Aneurysm Sac Embolization at the Time of Endografting

PURPOSE

To describe the procedural details for primary prevention of type II endoleak with fibrin glue injection into the aneurysm sac at the time of endografting.

TECHNIQUE

After deployment of the main stent-graft component, the angiographic pigtail catheter is withdrawn, leaving the 0.035-inch standard guidewire between the endograft and the native aorta. Through a brachial-femoral arterial guidewire loop, an 11-cm-long, 6-F introducer is advanced over the wire into the contralateral iliac artery. After deployment of the contralateral iliac extension, a 23-cm, 5-F sheath is advanced over the wire into the aneurysm sac. The wire and vessel dilator are removed, leaving the cannula in the sac. To prevent distal embolization of the sealant, a balloon is inflated in the contralateral limb to secure it to the native vessel before 5 mL of fibrin sealant are injected into the sac via a double-syringe delivery system inserted through the sheath. The balloon is left in place for 1 minute after sealant injection. In 64 consecutive patients in whom this technique has been used, sac embolization has been successful. There have been no intraoperative complications or in-hospital mortality. Over a mean follow-up of 9.3+/-4.4 months (range 1-18), only 1 lumbar endoleak has been detected on surveillance imaging.

CONCLUSIONS

This preventive strategy appears to be an effective approach and the best therapeutic choice for preventive management of type II endoleak.

Six-Year Experience With Talent Stent-Graft Repair of Abdominal Aortic Aneurysms

PURPOSE

To report a long-term experience with the Talent Endoprosthesis for the treatment of abdominal aortic aneurysm (AAA).

METHODS

In the period between June 1997 and June 2003, 193 patients (171 men; mean age 71.0+/-7.8 years, range 52-89) with AAA were treated with a Talent Endoprosthesis. Patients were clinically and radiologically followed in the postoperative period, at 30 days, and then annually up to 72 months. In addition to computed tomographic scans, a plain abdominal radiogram was also performed annually for structural assessment of the stent-graft.

RESULTS

Implantation success was 99.0% (191/193). Delivery system introduction was the cause of 1 failure, and the other patient was converted to surgery for intraprocedural device migration. There were 10 (5.2%) endoleaks (3 type I, 7 type II) at 30 days; all type I and 3/7 type II endoleaks were treated (93.3% secondary clinical success). Seven (3.7%) patients died in the perioperative period, including the conversion. During follow-up, 18 (9.3%) additional deaths occurred, and 4 new endoleaks (1 type I, 2 type II, 1 type III) were encountered. In up to 6 years' follow-up, the Talent Endoprosthesis did not present signs of material fatigue, but 1 component disconnection at 42 months led to death. There was no aneurysm rupture. After an initial increase in the aortic neck (1.2+/-1.1 mm) in the postoperative period, the neck diameters continued to increase until after the third year. An average reduction of 5.6+/-4.1 mm in the aneurysm diameter at 1 year was noted; the reduction gradually reached 14.1+/-10.7 mm after 60 months.

CONCLUSIONS

The Talent Endoprosthesis was an efficient alternative for managing AAAs, achieving low morbidity and mortality rates and a good long-term clinical outcome in this study. The Talent Endoprosthesis did not present signs of material fatigue over a 6-year follow-up.

Preoperative embolization of collateral side branches: a valid means to reduce type II endoleaks after endovascular AAA repair

PURPOSE

To report the results of preprocedural embolization of collateral branches arising from abdominal aortic aneurysms (AAA) scheduled for endovascular repair.

METHODS

Twenty-three consecutive AAA patients (all men; mean age 73 years, range 56-82) had coil embolization of patent lumbar and inferior mesenteric arteries (IMA) in a staged procedure prior to endovascular repair. Embolization with microcoils was attempted in 37 of the 52 identified lumbar arteries and 14 of 15 inferior mesenteric arteries. Follow-up included biplanar abdominal radiography, spiral computed tomography, and duplex ultrasonography at 1, 30, 90, and 180 days after the stent-graft procedure and at 6-month intervals thereafter.

RESULTS

Successful embolization was obtained in 24 (65%) of lumbar arteries, while all 14 (100%) IMAs were occluded with coils. No complication was associated with embolotherapy. Over a mean 17-month follow-up of 22 patients (1 intraoperative death), there was only 1 (4.5%) type II endoleak from a patent lumbar artery, with no sac expansion after 2 years. There were 4 (18%) type I and 1 (4.5%) type III endoleaks.

CONCLUSIONS

The embolization of side branches arising from an infrarenal aortic aneurysm before endovascular repair is feasible, with a high success rate; this maneuver may play a relevant role in reducing the rate of type II endoleak, improving long-term outcome.

CT-guided percutaneous embolization of a lumbar artery maintaining a type II endoleak

PURPOSE

To demonstrate the possibility of percutaneous embolization of a type II endoleak guided by computed tomographic (CT) fluoroscopy.

CASE REPORT

A type II endoleak maintained by a hypertrophic fourth lumbar artery failed to occlude spontaneously 7 months after stent-graft deployment for endovascular repair of an infrarenal abdominal aortic aneurysm. A percutaneous procedure was performed to eliminate the endoleak using needle puncture and embolization under CT fluoroscopic guidance. The sagittal diameter of the aneurysm sac, which had remained constant after initial endovascular exclusion, shrank from 5.2 to 4.8 cm in the 3 months following embolization.

CONCLUSIONS

Percutaneous embolization of lumbar branches guided by CT fluoroscopy may be an alternative to other therapies for type II endoleaks.

Failed AAA endograft exclusion due to type II endoleak: explant analysis

PURPOSE

To report the patient history and analysis of an explanted modular bifurcated endograft that was implanted to exclude an abdominal aortic aneurysm (AAA).

CASE REPORT

An 80-year-old man with a 6-cm AAA underwent uneventful endovascular implantation of a bifurcated AneuRx stent-graft. His postprocedural clinical course was uneventful, although persistent contrast enhancement of the aneurysm remained via the inferior mesenteric artery (IMA). By 6 months, an endoleak connecting to the lumbar and mesenteric arteries became apparent. Over the ensuing 12 months, the endoleak and aneurysm enlarged; branch artery embolization was attempted in 4 percutaneous procedures. Despite successful IMA occlusion, the aneurysm continued to increase in diameter and volume, necessitating conversion to a conventional bypass at 20 months. Analysis of the explanted specimen revealed an intact endograft with fibrous incorporation of the stent framework at the proximal and distal fixation sites only; no incorporation of the endograft was noted within the aneurysm. The feeding channel for the endoleak was not identified.

CONCLUSIONS

Serial imaging is a vital component of endograft surveillance, and persistent type II endoleaks that cannot be completely embolized endanger the longevity of the aneurysm exclusion. Explant analysis can play an important role in understanding the mechanisms of endograft failure.

An endoluminal method of hemorrhage control and repair of ruptured abdominal aortic aneurysms

PURPOSE

To report our initial experience with endovascular grafting to treat ruptured abdominal aortic aneurysms (AAAs).

METHODS

Three consecutive patients with severe comorbid illnesses and symptoms of aneurysm rupture and hemodynamic instability were treated with aortomonoiliac grafts. The Z-stent-based devices were implanted with the assistance of an occlusion balloon placed in the distal descending thoracic aorta.

RESULTS

All patients survived the procedure with successfully excluded AAAs. Two patients had relatively short hospital stays (4 and 14 days), while the third required prolonged treatment for pre-existing conditions. All patients required blood transfusions; 2 developed significant coagulopathies. Definitive management was delayed significantly by imaging protocols and graft construction.

CONCLUSIONS

Endovascular repair of ruptured aortic aneurysms is feasible. Proximal aortic control is readily attainable with the use of an aortic occlusion balloon placed through the left axillary artery. The absence of a laparotomy, extensive retroperitoneal dissection, and aortic cross-clamping likely contributes to patient survival; however, the delay in operative therapy to obtain adequate imaging and construct an endograft could be a hindrance to the ultimate success of this approach. The concepts of alternative aortic imaging techniques and endograft design, construction, and storage must be addressed.