Extra-Anatomical Bypass for Repair of Adult Distal Arch Restenosis

Surgical correction of redo complex aortic pathology through the same thoractomy incision can be associated with significant risks, including re-entry into a possibly frozen hemithorax. This could lead to injury to nerves and, more importantly, bleeding from hugely dilated collateral intercostal arteries, precluding optimal surgical repair (1). A single-stage approach via median sternotomy provides several distinct advantages (2).

The authors present a case of a 20-year-old man with a history of hypoplastic arch operated on at the age of 13 years old by patch augmentation through a left thoracotomy. He presented with symptoms of severe hypertension, requiring a high dose of medications, in addition to severe fatigue. On examination, there was strong pulsation on the right radial artery compared with weak pulsation on the left radial and both femoral arteries. By auscultation, there was systolic murmur radiated to the back and the gradient was about 40 mm hg. The discussion of the case with the interventionalist confirmed the difficulty of stenting and ballooning. 

The CT angiogram from the age of 13 showed severe stenosis between the left common carotid and left subclavian arteries. The new CT angiogram on the recent presentation showed restenosis at the same previous area. The echo of the patient showed mild aortic regurgitation, mild left ventricular hypertrophy, and trileaflet valve without significant stenosis.

On operation, the right radial and left femoral pressure catheters were applied and showed a gradient of 35 mm hg. The patient underwent a standard median sternotomy, and cardiopulmonary bypass was instituted by using an arterial cannula 22 French high in the ascending aorta and 16 French right femoral artery cannula with bicaval cannulae and LA venting through the right superior pulmonary vein. The authors prefer bicaval cannulation because this will not compromise the venous return. This further facilitates exposure of the distal descending thoracic aorta for construction of the distal anastomosis. Aortic cross-clamp with cold crystalloid cardioplegic arrest was used to do the distal anastomosis. The posterior pericardium was opened in a longitudinal fashion over the descending thoracic aorta just cephalad to the diaphragm, paying attention to the nearby esophagus, which was identified using a TEE probe. The distal anastomosis was constructed using a running 4-0 polypropylene suture after the application of a side-biting clamp. Usually, an 18 mm to 22 mm vascular graft will suffice for most adults (3). The authors’ graft size was 20 and the length 25 cm. The graft was then passed posterior to the inferior vena cava on the right side along the free wall of the right atrium. The proximal anastomosis was performed in the same manner as the distal anastomosis using a partial occluding clamp and a running 4-0 polypropylene suture on beating heart. Ensuring hemostasis of both anstomosis is crucial. Getting off bypass and decanulation was done without any problems. 

The postoperative course of five days was uneventful. Echo and CT angiogram before discharge showed good flow and good laying of the graft. 

References 

1. Salvania A, Nair HR, Pitchai S, Unnikrishnan M. Extra-anatomic ascending to descending thoracic aortic bypass for repair of adult aortic recoarctation. J Vasc Surg Cases Innov Tech. 2018 Jun;4(2):182-183.
2. Connolly HM, Schaff HV, Izhar U, Dearani JA, Warnes CA, Orszulak TA. Posterior pericardial ascending-to-descending aortic bypass: an alternative surgical approach for complex coarctation of the aorta. Circulation. 2001;104;133-1337.
3. Thurber J, Deb S, Collazo L. Ascending-To-Descending Aortic Bypass For Coarctation of the Aorta. CTSNet.  CTSNet. June 2008.

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