One-Stage Repair of Extensive Thoracic Aortic Aneurysm Using the Arch-First Technique and Bilateral Anterior Thoracotomy

The patient is positioned in a modified right lateral decubitus position with the left hemithorax elevated 30°. The left arm is suspended over the head. The right arm is tucked in at the side. The right subclavicular space and the right groin are included in the operative field. A 4- to 5-cm transverse incision is made beneath the right clavicle for exposure of the right axillary artery. Simultaneously, a 4- to 5-cm incision is made in the right groin crease to expose the right common femoral artery and femoral vein. The long dashed line indicates the site of the bilateral anterior thoracotomy incision.

(A) After administration of heparin, an 8- or 10-mm (according to the size of the axillary artery and the patient) collagen- or gelatin-impregnated polyester graft is sutured end-to-side to the right axillary artery using a 6-0 polypropylene suture and connected to one of two arterial lines from the pump-oxygenator. (B) The right common femoral vein is cannulated through a transverse venotomy with a two-stage cannula, positioning the tip in the superior vena cava using transesophageal echocardiography. The right femoral artery is cannulated with a short-tipped arterial cannula and connected to a second arterial line from the pump-oxygenator. a. = artery; Rt = right; SVC = superior vena cava.

The chest is entered through the fourth intercostal space bilaterally. The incision is extended to the anterior axillary line on the right and to the mid-axillary line on the left. The internal thoracic artery pedicles containing the artery and the accompanying veins are ligated and divided and the sternum is divided transversely. Two chest wall retractors are inserted and the pericardium is incised to expose the aneurysm and the lateral wall of the right atrium.

Cardiopulmonary bypass is established using the axillary artery and the common femoral vein. A venting catheter is placed into the left ventricle through a purse-string suture in the right superior pulmonary vein. A balloon-tipped cardioplegia cannula is positioned in the coronary sinus through a purse-string suture in the right atrial wall.

Profound cooling is initiated. When the heart fibrillates, the ascending aorta is clamped and antegrade cold (4°C) blood cardioplegia is administered through a needle inserted proximal to the aortic clamp. If aortic clamping is not possible, only retrograde cardioplegia is used and is administered immediately after circulatory arrest is established. It is administered every 15 minutes thereafter. LITA = left internal thoracic artery; v. = vein.

During cooling, the pericardium is incised over the distal ascending aorta and the aortic arch. The left phrenic and left vagus nerves are identified and protected without isolation or traction. The origins of the innominate, left carotid and left subclavian arteries are gently dissected away from the aortic arch and the surrounding tissues. The left innominate vein is preserved.

The left inferior pulmonary ligament is divided to mobilize the left lung and the distal limit of excision of the descending thoracic aorta is identified. The aorta is encircled at this level. During these maneuvers, only gentle traction must be applied to the left lung to minimize the risk of intraparenchymal hemorrhage. a. = artery; v. = vein.

When adequate cooling has been achieved, as determined by an isoelectric electroencephalogram and a nasopharyngeal temperature of at least 18°C, and after administration of methylprednisolone (7 mg/kg) and thiopental (10-15 mg/kg), and packing of the head in ice, circulatory arrest is established. The axillary arterial and femoral venous lines are clamped and a clamp is placed on the distal descending thoracic aorta below the aneurysm. The ascending aorta is incised vertically on the anterior surface and the incision is extended across the aortic arch up to the level of the left phrenic nerve. A separate incision is made in the descending thoracic aorta lateral to the left vagus nerve. The three brachiocephalic arteries are transected at their origins from the aorta and mobilized for several centimeters by sharp dissection. If necessary, they can be divided more distally to avoid areas of atheroma or dissection. a. = artery.

The clamp on the axillary artery graft is removed and perfusion from the axillary artery is slowly initiated to evacuate trapped air and debris from the brachiocephalic arteries. a. = artery.

The brachiocephalic arteries are sequentially clamped, beginning with the left subclavian, and flow (10 to 15 mL/kg) at a temperature of 20 to 22°C is established to the brain through the right carotid and right vertebral arteries. The average duration of hypothermic circulatory arrest of the brain necessary to accomplish these maneuvers is 9 minutes. Adequacy of flow to both cerebral hemispheres is assessed by monitoring of cerebral oxygen saturation using the Somanetics Invos Cerebral Oximeter (Somanetics Corp., Troy, MI). Flow to the lower body is initiated through the second arterial line placed in the right common femoral artery.

After brain perfusion is established, an aortic collagen- or gelatin-impregnated, branched aortic graft is positioned in the opened aortic arch. The distal limb of the graft is passed into the opened descending thoracic aorta beneath the left phrenic and left vagus nerves. The three adjacent branches of the aortic graft are cut to the appropriate lengths and sutured sequentially to the brachiochephalic arteries, beginning with the left subclavian and ending with the innominate, using continuous 5-0 polypropylene sutures. a. = artery.

After the branch anastomoses are completed, the aortic graft is clamped distal to the left subclavian artery. The clamps on the three branches are released, and air is eliminated from the proximal open end of the aortic graft. The aortic graft is then clamped just proximal to the innominate artery, and antegrade flow is established through the three arteries (arrows), maintaining the same flow rate, perfusion pressure, and temperature. The fourth branch of the aortic graft is ligated.

Arterial flow from the femoral artery cannula is discontinued; the clamp on the distal descending thoracic aorta is removed, and the aortic graft is anastomosed to the descending aorta at the appropriate level using a continuous 4-0 polypropylene suture reinforced with a strip of polytetrafluoroethylene felt. If chronic aortic dissection is present at the level of the anastomosis, the septum between the true and false channels is excised for 1 to 2 cm and the graft is sutured to the outer circumference of the aorta to permit perfusion of both lumens. Before completion of the anastomosis, air and debris are evacuated from the distal aorta and the graft by a burst of flow from the femoral arterial line. The suture line is completed; flow from the femoral line is discontinued and antegrade flow to the entire body is established from the axillary arterial line. Perfusate flow is increased and rewarming is initiated.

The clamp and the cardioplegia needle are removed from the proximal ascending aorta. The proximal end of the aortic graft is cut to the appropriate length and sutured to the ascending aorta with a continuous 4-0 polypropylene suture buttressed with a strip of polytetrafluoroethylene felt. Aortic valve or aortic root replacement and coronary artery bypass grafting, if indicated, are performed at this time. Before completion of the aortic anastomosis, the heart is filled with blood from the pump-oxygenator, and the lungs are inflated to evacuate air from the left heart. After the suture line is completed, a needle vent connected to suction is inserted into the anterior surface of the graft for continuous evacuation of air and the clamp on the aortic graft is removed.

Cardiopulmonary bypass is discontinued when rewarming is completed. The cardioplegia and left atrial venting catheters are removed and the purse-string sutures are secured. The axillary artery graft is doubly ligated near the artery and the excess graft is excised. The femoral arterial and venous cannulas are removed and the vessels are closed transversely with continuous 6-0 polypropylene sutures. Two atrial and two ventricular pacing wires are sutured in place and are brought out onto the anterior chest wall.

After hemostasis is obtained, the chest wall is approximated with multiple number 2 polyglactin pericostal sutures and two vertically placed number 6 wires to the sternum. Two drainage tubes are placed into each pleural space, one posteriorly and superiorly, and one posteriorly and inferiorly. The atrial and ventricular pacing wires are brought out onto the anterior chest wall. A 19-Fr silastic tube connected to bulb suction is placed in the submuscular layer on each side and small catheters are placed on the pericostal suture line on each side for administration of analgesic agents in the postoperative period. The skin edges are approximated with a subcuticular suture. The subclavian and groin incisions are closed in layers with a subcuticular closure of the skin. Sm = small.