Endovascular repair of ascending aortic pseudoaneurysms using the GORE TAG Thoracic Branch Endoprosthesis Proximal Extender

Abstract

Ascending aortic pseudoaneurysms (AAPs) are a rare but morbid complication after cardiac surgery. Although the mainstay of AAP treatment is open surgery, endovascular repair can be considered for high-risk surgical candidates with suitable anatomy. With no US Food and Drug Administration-approved devices for the treatment of zone 0 pathology, endovascular repair of AAP is being performed with off-label use of available devices. Here we present two cases of successful AAP exclusion using the GORE TAG Thoracic Branch Endoprosthesis Aortic Extender.

Ascending aortic pseudoaneurysms (AAPs) are a rare but morbid complication after cardiac surgery (<0.5% incidence), typically occurring at sites of aortic cannulation or anastomosis.1, 2, 3 For high-risk surgical candidates with suitable anatomy, endovascular repair is recommended in European guidelines (Class IIA, Level B).⁴ In the United States, there are no US Food and Drug Administration-approved devices for zone 0 pathology. Endovascular repair is performed off label.⁵ We present two cases of off-label endovascular AAP repair with the Gore TAG Thoracic Branch Endoprosthesis Aortic Extender (TBE-AE; W. L. Gore & Associates). The patients consented to publish case details and images.

Case report

Case 1

A 76-year-old man with hypertension, atrial fibrillation, heart failure, and mitral regurgitation with mitral valve repair and left atrial appendage ligation 18 months before presentation experienced a postoperative course complicated by sternal wound infection requiring multiple sternal washouts, wire removal, negative pressure wound therapy, and antibiotics for sternal osteomyelitis. Interval imaging demonstrated progression of an AAP at the aortic cannulation site from 9.59 × 9.28 × 5.89 mm (width × height × depth) to 12.02 × 7.56 × 9.33 mm over 3 months (Fig 1, A and B). Centerline analysis revealed coronary ostia (CO) to AAP length of 55.0 mm, AAP to innominate artery (IA) length of 10.2 mm, and a CO to IA length of 70.2 mm. Given the patient's high risk for redo sternotomy, he was referred for endovascular repair. The patient consented to proceed after a risk/benefit discussion.

Fig 1.

Case 1: ascending aortic pseudoaneurysm (AAP). Axial (A) and sagittal (B) images demonstrating a large, anterior AAP. Initial intraoperative angiogram (C) demonstrating the AAP (indicated by the red arrow). Completion angiogram (D) demonstrating the deployed TAG TBE Aortic Extender endograft, exclusion of the AAP, and a patent innominate artery (IA). One-month follow-up axial (E) and sagittal (F) images demonstrating exclusion of the AAP.

Under general anesthesia, bilateral common femoral artery and right radial artery access were obtained under ultrasound guidance and confirmed with fluoroscopy. A 6F sheath was advanced up the arm and positioned near the IA origin. An aortogram via the left femoral access identified the locations of the pseudoaneurysm, CO, and major arch vessels (Fig 1, C). A TAG TBE-AE (45 × 46 mm; W. L. Gore & Associates) was advanced into the ascending aorta (AA). A 10 × 40 mm balloon was advanced through the radial sheath and positioned across the IA origin, extending partially into the aorta. Rapid cardiac pacing was performed via a central venous pacer and the TBE-AE was deployed under fluoroscopic guidance. A postdeployment aortogram demonstrated exclusion of the pseudoaneurysm, a patent IA, and patent CO (Fig 1, D). As the endograft deployment system was withdrawn, the balloon at the IA origin was inflated to prevent distal graft displacement. Completion aortogram confirmed proper graft placement (Fig 1, D) (96 minutes procedure time; 50 mL estimated blood loss; 60 mL contrast; 2000 mL crystalloids; 1300 mL urine output.)

The patient had an uneventful postoperative course and was discharged on postoperative day 1 with lifelong antibiotics. At 1-month follow-up, computed tomography angiography (CTA) confirmed AAP exclusion (Fig 1, E and F).

Case 2

A 63-year-old man with a history of nephrectomy for renal cell carcinoma, end-stage renal disease, renal transplant, deep venous thrombosis, subarachnoid hemorrhage, and end-stage systolic heart failure with left ventricular assist device experienced a postoperative course complicated by driveline infection requiring rerouting, antibiotic therapy, and orthotopic heart transplant. Interval imaging demonstrated a 21.15 × 22.65 × 12.97 mm AAP at the aortic anastomosis. CTA performed 1 month later demonstrated size progression to 20.80 × 16.02 × 14.24 mm (Fig 2, A and B). Centerline analysis revealed CO to AAP length of 40.3 mm, AAP to IA length of 36.1 mm, and CO to IA length of 92.7 mm. The patient was referred for endovascular repair and consented to proceed after a risk/benefit discussion.

Fig 2.

Case 2: ascending aortic pseudoaneurysm (AAP). Axial (A) and coronal (B) images demonstrating a large AAP along the greater curve of the aorta. Initial intraoperative angiogram (C) demonstrating the AAP (indicated by the red arrow). Completion angiogram (D) demonstrating deployed TAG TBE Aortic Extender endografts, exclusion of the AAP, and a patent innominate artery (IA). Two-month follow-up axial (E) and coronal (F) images demonstrating exclusion of the AAP.

Bilateral common femoral access was obtained as previously described. An aortogram demonstrated a wide-necked AAP arising from the greater curve (Fig 2, C). A TBE-AE (40 × 40 mm) was advanced into the AA. The stent graft was deployed proximal to the IA takeoff under fluoroscopic guidance and rapid cardiac pacing. However, the graft jumped forward when removing the delivery system. An additional TBE-AE (40 × 40 mm) was deployed with adequate overlap to exclude the pseudoaneurysm fully. Balloon molding was performed using a GORE Tri-Lobe balloon. An aortogram demonstrated exclusion of the pseudoaneurysm, but a segment of uncovered aorta between the distal aspect of the graft and the IA origin. A third TBE-AE (40 × 40 mm) was deployed to cover this segment. Completion angiogram demonstrated exclusion of the pseudoaneurysm without encroachment on the CO or IA (Fig 2, D) (82 minutes procedure time; 200 mL estimated blood loss; 80 mL contrast; 1300 mL crystalloids; 350 mL urine output.)

The patient had an uneventful postoperative course and was discharged on postoperative day 1. The 1-month follow-up was unremarkable, and a 2-month postoperative CTA confirmed exclusion of the AAP (Fig 2, E and F).

Discussion

There is no standardized technique for zone 0 endovascular repair. The literature proposes 13 different stent grafts grouped into three repair strategies.^6,7 Approved thoracoabdominal aneurysm repair (TEVAR) stent grafts can be used off-label in the rare instances when the AA can accommodate a 10-cm device. Custom-ordered (eg, the Medtronic Valiant physician-sponsored investigational device exemption graft) or physician-modified grafts can be used; however, investigational device exemption centers are sparse and these options are unfeasible in acute settings. EVAR or TEVAR cuffs can be used off-label, particularly to cover focal defects. EVAR cuffs are typically undersized, requiring the deployment of multiple cuffs, and are mounted on short delivery systems complicating a transfemoral approach. A systematic review by Muetterties et al⁷ included 118 patients treated for zone 0 pathology (50% type A dissection, 29.7% AAP). Of these cases, TEVAR grafts treated 71.2%, EVAR cuffs treated 11%, and TEVAR cuffs treated 0.9% (1 case).⁷ Transfemoral access was most common (62.7% of cases), followed by transapical (14.4%), transcarotid (12.7%), and transaxillary (6.8%).⁷ Despite an all-cause mortality of 15.2% (5% aortic related),⁷ outcomes compared favorably with the cited mortality of proximal aortic replacement (elective cases, 3.4%; nonelective cases, 15.4%).⁸

Several anatomical considerations favored choosing the TAG TBE-AE. The need for a short length, large diameter endograft and a delivery system with adequate reach favored a thoracic device with standard femoral access. Proximal bare stents may interfere with critical structures (eg, aortic valve, CO) and limit the proximal seal zone. As such, devices with minimal bare stents are preferred (eg, TAG TBE, Zenith TX2). The TAG TBE and Zenith TX2's shortest grafts for the required aortic diameter would have covered critical structures. The TAG TBE-AE is much shorter (36-46 mm). Additionally, the TBE-AE's short nose cone minimized the risk of aortic valve injury (18 mm vs Zenith TX2's 72 mm).

Graft deployment in the AA must contend with shear stress, four-dimensional pulsatile and rotational movements, and proximity to critical structures. The TBE-AE has a single stage deployment mechanism—risking windsocking—and no active control for angulation in a steep arch—risking bird-beaking. Rapid cardiac pacing and IA origin protection with a balloon minimized zone 0 hemodynamic considerations and increased deployment accuracy. Short graft length increases the risk of incomplete coverage requiring additional graft material, as seen in case 2. Ballooning the IA as a backstop to prevent distal graft displacement has been described by interventional cardiology and radiology,^9,10 but not by vascular surgery. Although successful, angioplasty in healthy vessels risks rupture, intimal disruption, or dissection. Placing a zone 0 aortic graft carries the usual TEVAR risks—stroke, graft migration, endoleak, infection, or collapse.

Conclusions

We present an off-label repair of AAPs using the TAG TBE-AE. As we await approved devices for zone 0, off-label use of available devices offers a viable option for select high-risk individuals.

Funding

None.

Disclosures

S.S. is a consultant for W. L. Gore & Associates.