Hybrid treatment of a true thyreocervical trunk aneurysm in a patient with Type B aortic dissection

  • A 65yearold man with history of hypertension, hyperlipidemia, and CAD percutaneously treated had an acute Type B aortic dissection and treated with the implantation of a stentgraft which occluded the left subclavian artery due to its extension to the aortic arch.This event required a carotidsubclavian artery bypass due to ischemia of the left arm.

  • An aneurysm in the innominate artery was treated with another stentgraft implantation 3 months later.

  • At 5year followup, an aneurysm of the thyreocervical trunk was found while the stentgraft of the aorta was welltolerated without endoleak and the carotidsubclavian graft was patent. The aneurysm was asymptomatic of 44 mm but considering the risk of spontaneous rupture of an aneurysm, elective surgery was planned.

  • Initially, this finding was called aneurysm of the innominate artery but after sternotomy and preparation it was fund that is an aneurysm of the thyrocervical trunk.

  • Because the aneurysm was very close to the brachiocephalic bifurcation, open surgical repair would require a sternotomy. The right common carotid artery and right subclavian artery were exposed. The thyrocervical trunk, right internal mammary artery and right vertebral artery were occluded by ligations to isolate the aneurysm. An 8mm Dacron graft was anastomosed endtoend to the distal part of subclavian artery.

 

DISCUSSION

  • Hybrid cardiovascular surgery is a new way of treating complex pathologies of the aorta to minimize the complications and the risk of death.

  • Despite advances in surgical techniques, cerebral protection methods and postoperative management, the inhospital mortality rate for patients undergoing conventional open surgical repair for Type B dissections is still high.

  • The less invasive surgical procedure for acute Type  B aortic dissections is thoracic endovascular aortic repair  (TEVAR).

  • Usually, the entry point  tear of the intimal layer in Type B aortic dissection is located in the vicinity of the orifice of the left subclavian artery

  • During the endovascular treatment of the Type B aortic dissection, the LSA must be occluded to secure the proximal landing zone. If LSA occlusion occurs, a LSA bypass is done for complete aortic arch revascularization.

  • This requires hybrid surgery that includes the use of open surgical procedures, such as debranching for revascularization of cervical branches and the endovascular stent graft implantation through the right femoral artery.

  • In general, aortic dissections are categorized as acute (the period within 14 days of onset) and chronic (the period more than 14 days after onset).

  • Symptomatic cases (e.g., rupture, malperfusion, continuous pain, and refractory hypertension) are classified as complicated, whereas those patients without such conditions are defined as uncomplicated.

  • To avoid an aortic arch and descending aorta replacement with cardiopulmonary bypass, total circulatory arrest, and deep hypothermia, the patient was offered a less invasive hybrid endovascular procedure.

  • Despite these complex diseases, the patient was treated successfully, and this fact determines the utility of the endovascular and the hybrid cardiovascular surgery.

    dissection
    Figure 1: Computed tomography scan images showing the previously implanted stent graft (thoracic endovascular aortic repair) due to Type B thoracic aorta dissection with perfect dissenting thoracic aorta remodeling in current time.
    dissection2
    Figure 2: Compounded tomography images showing previously implanted cover stent due to pre-existing aneurysm of innominate artery.

     

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    Figure 3: CT scan images demonstrating a new aneurysm of 4.4 cm max diameter beside the cover stent at the innominate artery

     

    Read full Article at : Annals of Cardiac Anesthesia

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