TAMBE thoracoabdominal branch endoprosthesis for complex aortic aneurysm repair

Surgeons at Penn Medicine are employing the Gore Excluder thoracoabdominal branch endoprosthesis (TAMBE) system to repair complex aneurysms of the visceral segment of the aorta.

Pararenal abdominal aortic aneurysms (PAAAs) are characterized by extension to, and involvement of, the renal arteries. When aortic aneurysms involve the superior mesenteric and celiac arteries they are characterized as thoracoabdominal aortic aneurysms (TAAAs). They are generally asymptomatic and are thus of great concern for sudden fatal rupture.

Risks of surgery in complex abdominal aortic aneurysms

Prophylactic surgery to prevent rupture is generally recommended when AAAs reach 5.5 cm. Approximately 85% of all AAAs are located below the renal arteries and may be repaired through open surgery or standard endovascular stent-graft repair (EVAR). With complex aortic aneurysms like PAAAs or TAAAs, however, standard EVAR is not an option.

Traditionally, these aneurysms required a highly complex open surgical repair with reimplantation or the renal or mesenteric arteries. Many patients, especially those with medical comorbidities, are not candidates for these risky surgeries. In such high-surgical risk patients, options for repair may be limited to the use of specialized custom fenestrated/branched endovascular grafts, including the TAMBE system.

TAMBE, an off-the-shelf solution for PAAAs/TAAAs

Now available at Penn Medicine, the Gore Excluder thoracoabdominal branch endoprosthesis (TAMBE) system is an aortic stent graft indicated for endovascular repair in complex high-surgical-risk patients with pararenal aortic aneurysms and thoracoabdominal aortic aneurysms. FDA-approved in 2024, TAMBE is currently the only off-the-shelf endovascular repair device available for complex aneurysmal disease of the visceral aorta in the United States.

The TAMBE system consists of three principal components, including:

• A multi-branched aortic graft that spans the thoracic aorta at the visceral segment. Comprised of four precannulated internal portals and branches, the graft supplies blood to the celiac, superior mesenteric, and renal arteries.
• A balloon expandable endoprosthesis, that as a pre-mounted bridging stent graft creates a secure connection to span the gap and seal the connection between the fenestrations in the main graft and the renal, celiac, and superior mesenteric arteries.
• A distal bifurcated anchoring component comprised of contralateral extensions and deployed at the iliac arteries subsequent to the above-mentioned procedures.

In addition, use of the TAMBE device involves guide wires, dilators, sheaths, cannulas, and closure devices coordinated throughout the procedure as needed.

Outcomes

Early TAMBE device outcomes in individuals who took part in the TAMBE prospective, nonrandomized, pivotal clinical study (AAA 17-01) have been promising. In this study population, which included individuals with extent IV thoracoabdominal aortic aneurysms (TAAAs) or PRAAs, 94.1% of patients were living, target vessel stability was 94.2%, and renal artery primary patency was 91.8%. Aortic enlargement of >5 mm occurred in 5.4% of patients, but none experienced postoperative aneurysm rupture. This was an atypical finding: at 12 months, 23.8% of evaluable patients had aneurysm shrinkage of >5 mm; 70.2% had an aneurysm size within 5 mm of baseline measurement.

Mrs. C, a frail 71-year-old, was referred to John D. Affuso, MD, at Penn Medicine Lancaster General Health for surgical evaluation in light of a recently diagnosed pararenal abdominal aortic aneurysm. At LGH, imaging confirmed a 5.5 cm pararenal abdominal aortic aneurysm with issues precluding standard stent graft devices and open surgery. Given these risks, it was decided that Mrs. C’s surgery could best be addressed by a percutaneous endovascular AAA repair employing the TAMBE device. After explaining the procedure including the risks and benefits, Mrs. C agreed to proceed.

The procedure: Complex surgeries of this type often involve two surgeons. In this case, Shilpa Agarwal, MD—the newest member of the Vascular Surgery team at Penn Medicine—brought her experience with the TAMBE device the help with Mrs. C’s case. The object of Mrs. C’s procedure was to exclude a 5.5 cm pararenal aneurysm involving her visceral arteries. To this end, her surgery was performed in a specialized hybrid operating room which allowed for real-time imaging to confirm the safety and accuracy of instrument placement, and operative success.

In brief, Mrs. C was placed under general anesthesia. The TAMBE endoprosthesis was then advanced into the thoracic portion of the aorta above the mesenteric and renal arteries. Following selective cannulation of the celiac artery, the superior mesenteric artery, and the right and left renal arteries, balloon expandable stent grafts were placed through the respective ports into these vessels. After all the branches were successfully completed, a bifurcated Gore Excluder endoprosthesis was deployed into the right and left common iliac arteries. Final imaging showed no evidence of endoleak, and patency at all mesenteric and renal stents (see Figure 1).

Postoperatively, Mrs. C did well. At her one month postop visit, she was back home with her husband and doing well. A postoperative CT scan showed her TAMBE stent to be effectively excluding her aneurysm with patency of all her branches.

About Vascular Surgery at Penn Medicine Lancaster General Health

Penn Medicine Lancaster General Health is nationally recognized for its full spectrum of adult cardiac and vascular procedures, ranging from minimally invasive techniques to highly complex surgeries. Specialists take a patient-centric, multidisciplinary approach, guiding individuals through every phase from the initial diagnostic testing to the surgical procedure and rehabilitation.

Referrals and consultations

To refer a patient to Penn Medicine Lancaster General Health, please call the 24/7 provider-only line at 877-937-7366 or submit a referral through our secure online referral form.