John P. Henretta

Special iliac artery considerations during aneurysm endografting.

BACKGROUND The feasibility of endograft exclusion of abdominal aortic aneurysms (AAA) has been established. However, the technical challenges of graft delivery through tortuous or diseased iliac arteries and the treatment of associated iliac aneurysmal disease have received little attention. METHODS Over 19 months, 74 patients underwent endoluminal repair of AAA and/or iliac artery aneurysms. Iliac anatomy that required special consideration during endografting was reviewed. RESULTS Of the 74 patients, 35 (47%) had iliac anatomy that required special attention. Thirteen patients (18%) had aneurysmal involvement of a common iliac artery. Eleven of these patients required endograft extension into the external iliac artery (EIA) and hypogastric coil embolization due to the proximity of the aneurysm to the hypogastric origin. Eleven patients with ectatic, nonaneurysmal iliac arteries required aortic cuffs to achieve a distal seal in these oversized vessels. Iliac artery tortuosity or stenosis were complicating factors in 27 of the 74 patients (36%), requiring the use of brachial guidewire tension in 2 patients to facilitate tracking of the delivery device. Five patients with severely splayed aortic bifurcations required crossed placement of the iliac limbs to prevent kinking of the endograft. Occlusive atherosclerotic disease of the EIA mandated preprocedural dilatation and stenting in 3 patients and postprocedural surgical EIA reconstruction in another 5 patients. Three patients who underwent successful endograft placement required subsequent endovascular repair of traumatized EIAs. CONCLUSIONS Iliac artery anatomy plays a significant role in the endoluminal treatment of infrarenal abdominal aortic aneurysms, complicating the procedure in up to 47% of patients with otherwise suitable anatomy. A variety of supplemental procedures, both surgical and endovascular, may be required to facilitate endograft placement. A special understanding of these constraints and proper planning is required for optimal therapy.

Feasibility of endovascular repair of abdominal aortic aneurysms with local anesthesia with intravenous sedation

PURPOSE Local anesthesia has been shown to reduce cardiopulmonary mortality and morbidity rates in patients who undergo selected peripheral vascular procedures. The efforts to treat abdominal aortic aneurysms (AAAs) with endovascular techniques have largely been driven by the desire to reduce the mortality and morbidity rates as compared with those associated with open aneurysm repair. Early results have indicated a modest degree of success in this goal. The purpose of this study was to investigate the feasibility of endovascular repair of AAAs with local anesthesia. METHODS During a 14-month period, 47 patients underwent endovascular repair of infrarenal AAAs with local anesthesia that was supplemented with intravenous sedation. Anesthetic monitoring was selective on the basis of comorbidities. The patient ages ranged from 48 to 93 years (average age, 74.4 +/- 9.8 years). Of the 47 patients, 55% had significant coronary artery disease, 30% had significant chronic obstructive pulmonary disease, and 13% had diabetes. The average anesthesia grade was 3.1, with 30% of the patients having an average anesthesia grade of 4. The mean aortic aneurysm diameter was 5.77 cm (range, 4.5 to 12.0 cm). All the implanted grafts were bifurcated in design. RESULTS Endovascular repair of the infrarenal AAA was successful for all 47 patients. One patient required the conversion to general anesthesia to facilitate the repair of an injured external iliac artery via a retroperitoneal approach. The operative mortality rate was 0. No patient had a myocardial infarction or had other cardiopulmonary complications develop in the perioperative period. The average operative time was 170 minutes, and the average blood loss was 623 mL (range, 100 to 2500 mL). The fluid requirements averaged 2491 mL. Of the 47 patients, 46 (98%) tolerated oral intake and were ambulatory within 24 hours of graft implantation. The patients were discharged from the hospital an average of 2.13 days after the procedure, with 87% of the patients discharged less than 48 hours after the graft implantation. Furthermore, at least 30% of the patients could have been discharged on the first postoperative day except for study protocol requirements for computed tomographic scanning at 48 hours. CONCLUSION This is the first reported series that describes the use of local anesthesia for the endovascular repair of infrarenal AAAs. Our preliminary results indicate that the endovascular treatment of AAAs with local anesthesia is feasible and can be performed safely in a patient population with significant comorbidities. The significant potential advantages include decreased cardiopulmonary morbidity rates, shorter hospital stays, and lower hospital costs. A definitive evaluation of the benefits of local anesthesia will necessitate a direct comparison with other anesthetic techniques.

Algorithm for the diagnosis and treatment of endoleaks.

BACKGROUND Endoluminal grafting of abdominal aortic aneurysms (AAA) has shown promising early results. However, endoleaks present a new and challenging obstacle to successful aneurysm exclusion. We report our experience with primary, persistent endoleaks and provide an algorithm for their diagnosis and management. METHODS Over a 19-month period, 73 patients underwent endoluminal repair of their AAAs using a modular bifurcated endograft as part of a US FDA Investigational Device Exemption trial. Spiral computed tomography (CT) scanning was performed prior to discharge after repair to evaluate for complete aneurysm exclusion. If no endoleak was present on that initial CT scan, color-flow duplex scanning was performed at 1 month, with repeat CT scanning at 6 months and 1 year. If the initial CT scan revealed the presence of an endoleak, repeat CT scanning was performed at 2 weeks, 1 month, and 3 months, or until the endoleak resolved. Any patient with an endoleak that persisted beyond 3 months underwent angiographic evaluation to localize the source of the leak. RESULTS At 1 month, 62 patients (85%) had successful aneurysm exclusion. The remaining 11 patients (15%) had primary endoleaks, 8 (11%) of which persisted beyond 3 months, prompting angiographic evaluation. In 2 patients the endoleak was related to a graft-graft or graft-arterial junction. One was from the endograft terminus in the common iliac artery and was successfully embolized, along with its outflow lumbar artery. The other required placement of an additional endograft component across a leaking graft-graft junction to successfully exclude the aneurysm. The remaining six endoleaks were due to collateral flow through the aneurysm sac. In 4 cases this was lumbar to lumbar flow fed by hypogastric artery collaterals to the inflow lumbar artery. In the remaining 2 patients the endoleak was found to be due to flow between a lumbar and inferior mesenteric artery. Resolution of the endoleak by coil embolization of the feeding hypogastric artery branch in 1 patient was unsuccessful due to rapid recruitment of another hypogastric branch. Two of the six collateral flow endoleaks have resolved spontaneously without treatment, while the remaining cases have been followed up without evidence of aneurysm expansion. CONCLUSION Systematic postoperative surveillance facilitates proper diagnosis and treatment of endoleaks. This involves serial CT scans to detect the presence of endoleaks, followed by angiography to determine their etiology and guide treatment, if clinically indicated.

Outcome-based anatomic criteria for defining the hostile aortic neck

OBJECTIVE There is abundant evidence linking hostile proximal aortic neck anatomy to poor outcome after endovascular aortic aneurysm repair (EVAR), yet the definition of hostile anatomy varies from study to study. This current analysis was undertaken to identify anatomic criteria that are most predictive of success or failure at the aortic neck after EVAR. METHODS The study group comprised 221 patients in the Aneurysm Treatment using the Heli-FX Aortic Securement System Global Registry (ANCHOR) clinical trial, a population enriched with patients with challenging aortic neck anatomy and failure of sealing. Imaging protocols were not protocol specified but were performed according to the institutions standard of care. Core laboratory analysis assessed the three-dimensional centerline-reformatted computed tomography scans. Failure at the aortic neck was defined by type Ia endoleak occurring at the time of the initial endograft implantation or during follow-up. Receiver operating characteristic curve analysis was used to assess the value of each anatomic measure in the classification of aortic neck success and failure and to identify optimal thresholds of discrimination. Binary logistic regression was performed after excluding highly intercorrelated variables, creating a final model with significant predictors of outcome after EVAR. RESULTS Among the 221 patients, 121 (54.8%) remained free of type Ia endoleak and 100 (45.2%) did not. Type Ia endoleaks presented immediately after endograft deployment in 58 (58.0%) or during follow-up in 42 (42.0%). Receiver operating characteristic curve analysis identified 12 variables where the classification of patients with type Ia endoleak was significantly more accurate than chance alone. Increased aortic neck diameter at the lowest renal artery (P = .013) and at 5 mm (P = .008), 10 mm (P = .008), and 15 mm (P = .010) distally; aneurysm sac diameter (P = .001), common iliac artery diameters (right, P = .012; left, P = .032), and a conical (P = .049) neck configuration were predictive of endoleak. By contrast, increased aortic neck length (P = .050), a funnel-shaped aortic neck (P = .036), and neck mural thrombus content, as measured by average thickness (P = .044) or degrees of circumferential coverage (P = .029), were protective against endoleak. Binary logistic regression identified three variables independently predictive of type Ia endoleak. Neck diameter at the lowest renal artery (P = .002, cutpoint 26 mm) and neck length (P = .017, cutpoint 17 mm) were associated with endoleak, whereas some mural neck thrombus content was protective (P = .001, cutpoint 11° of circumferential coverage). CONCLUSIONS A limited number of independent anatomic variables are predictive of type Ia endoleak after EVAR, including aortic neck diameter and aortic neck length, whereas mural thrombus in the neck is protective. This study suggests that anatomic measures with identifiable threshold cutpoints should be considered when defining the hostile aortic neck and assessing the risk of complications after EVAR.

Analysis of EndoAnchors for endovascular aneurysm repair by indications for use.

OBJECTIVE The proximal aortic neck remains one of the challenges of endovascular aneurysm repair (EVAR), and the risk of type Ia endoleak and endograft migration is increased in patients with short, large-diameter, or highly angulated necks. EndoAnchors have been used as an adjunct to EVAR in such patients, and the aim of this study was to assess their benefit analyzed by indication for use. METHODS During a 2-year period, 319 patients were enrolled at 43 sites in the Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR) study. This prospective, multinational, real-world analysis of EndoAnchors comprised two groups of patients, those undergoing first-time EVAR (primary arm, 242) and those with proximal neck complications remote from the time of an initial endograft implantation (revision arm, 77). The primary arm was further subdivided into patients undergoing prophylactic EndoAnchor use for hostile proximal neck anatomy (178), with a type Ia endoleak evident during initial endograft deployment (60), and in conjunction with extender cuffs after unsatisfactory endograft deployment distally in the neck (four). The revision arm was subdivided into patients presenting with a type Ia endoleak alone (45), endograft migration alone (11), and migration with endoleak (21). Technical success was site reported as satisfactory deployment of the desired number of EndoAnchors without fracture or loss of integrity. Procedural success was defined as technical success without type Ia endoleak at completion arteriography. Core laboratory analysis was performed on 249 baseline and 192 follow-up computed tomographic studies, 66 of which were available within the 1-year window. RESULTS Technical and procedural success rates were highest in the prophylactically treated subset (172 of 178; 96.6%). Whereas the technical success of EndoAnchor deployment was also high in the other subsets, residual type Ia endoleaks were more frequent at completion angiography when the indication for EndoAnchor use was type Ia endoleak, both in the primary arm (17 of 60; 28%) and in the revision arm (9 of 45; 20%). During a median imaging follow-up of 7 months, 183 of 202 patients (90.1%) remained free of type Ia endoleaks. Primary prophylactic patients were free from type Ia endoleak in 110 of 114 cases (96.5%). The most challenging subset was revision patients treated for type Ia endoleak; type Ia endoleaks were evident during follow-up in 10 of 29 of the cases (34%). Sac regression >5 mm in patients with 1-year imaging was observed in 26 of 66 patients (39%) and was highest in the primary prophylaxis subset (20 of 43; 47%). CONCLUSIONS EndoAnchor implantation can be a useful adjunct to EVAR as prophylaxis against proximal attachment site complications in patients with hostile aortic neck anatomy, as treatment for early and late type Ia endoleaks, or, in conjunction with aortic extension cuffs, for endograft migration. Whereas the most challenging patients are those who present with type Ia endoleaks remote from initial EVAR, EndoAnchors are still effective in treating the majority of these cases.

Outcome of the pivotal study of the Aptus endovascular abdominal aortic aneurysms repair system

OBJECTIVE Endovascular treatment of abdominal aortic aneurysm (AAA) is associated with benefits over open surgery, yet limitations remain with current endovascular devices. This study was performed to assess outcomes of AAA repair with the Aptus endograft and EndoAnchors (Aptus Endosystems, Sunnyvale, Calif). METHODS This prospective, multicenter, single-arm investigational device exemption trial was conducted at 25 sites in the United States. A total of 155 patients were enrolled in the trial (mean age, 73 ± 8 years; male, 93.5%; mean AAA diameter, 53.6 ± 7.9 mm). The Aptus endograft is a two-component system: a multilumen, modular endograft with two docking limbs (Aptus Endograft System) and the Heli-FX Aortic Securement System comprising an electronically controlled applier (Heli-FX Applier) with helical EndoAnchors provided in a cassette and a deflectable sheath (Heli-FX Guide) designed for delivery of the applier to the target location for EndoAnchor implantation. The main eligibility criteria included proximal neck length of ≥12 mm, diameter of 19 to 29 mm, and infrarenal angulation of ≤60 degrees. The primary safety end point was freedom from major adverse events at 30 days, and the primary effectiveness end point was successful aneurysm treatment at 12 months. Thrombus-related events (TRE) were defined as limb occlusion or thromboembolism from the endograft. Subjects were observed for a median of 4.2 years, with imaging end points analyzed by a core laboratory and adverse events adjudicated by a clinical events committee. RESULTS Among 155 enrolled subjects, 153 (98.7%) underwent successful implantation of the Aptus endograft and a median of five EndoAnchors; two subjects were converted to open surgical repair during the initial procedure. Overall, the primary safety and effectiveness end points were met in 98.1% and 97.4% of the subjects, respectively. Aneurysm-related mortality was 0.6%, with one postdischarge cardiac death 18 days after implantation. There were no AAA ruptures. There were no fractures of stents or EndoAnchors. There was one type I endoleak and one type III endoleak. Stent graft migration was noted in five subjects, none associated with sac enlargement, type I endoleak, or EndoAnchor dislocation from the endograft. AAA sac shrinkage of ≥5 mm at 1, 2, and 3 years was observed in 60.3%, 72.9%, and 81.7%, respectively. Sixty-one subjects (39.4%) experienced 113 TRE, associated with 80 reinterventions (in 58 subjects) unassociated with limb loss or death. A root cause analysis of TRE identified small, out-of-specification docking limbs with graft infolding and high local shear, resulting in thrombus formation within the endograft with subsequent distal embolization in some cases. CONCLUSIONS Early results of the Aptus endograft trial met its safety and effectiveness end points; however, a high rate of TRE was observed because of manufacturing discrepancies. The findings confirm a low rate of type I and type III endoleaks, migration, and non-TRE reintervention with a high rate of aneurysm sac regression during midterm follow-up.

Postintervention Surveillance of Endovascular Procedures

As endovascular therapies gain increased acceptance for the treatment of vascular disease, postintervention surveillance becomes more critical. The underlying rationale for routine, systematic follow-up is multifactorial. The primary reason is to improve the results of treatment by detecting failures or recurrences early enough in their course that their correction is as minimally involved as possible. It has been well demonstrated, for example, that correction of a threatened saphenous vein bypass improves its patency when compared to simple observation.1–3 This finding is thought to be applicable to endovascular therapies as well: Treatment of a recurrent stenosis with a second endovascular procedure, perhaps with supplemental stenting, is more likely to be initially technically successful and durable than an attempt to recannulate an occlusion that results from ignoring the recurrence. Furthermore, treatment of an occlusion may require thrombolysis, which has its own inherent risks. The advantages of close postintervention surveillance become even more obvious when dealing with an artery feeding an end-organ (e.g., the renal artery), in which case progression to occlusion may cause irretrievable organ injury.