An 82-year-old Japanese female [height 100 cm, weight 27 kg, body surface area (BSA) 0.82 cm2] who was diagnosed with achondroplasia at birth based on the short stature and lateral curvature of the spine was admitted to our hospital because of acute-onset severe chest pain migration to her back accompanied by numbness and pain in the right lower limb. Her medical history was significant for achondroplasia, hypertension, and chronic obstructive pulmonary disease. A computed tomography (CT) scan revealed a dissection flap in the dilated ascending aorta that extended through the aortic arch to the bilateral iliac arteries (Fig. 1a). In addition, the great vessels of the aortic arch and the major abdominal branches communicated with the true lumen. However, an occlusion was reported in the right common iliac artery (Fig. 1b and c). Although electrocardiography revealed normal sinus rhythm with no apparent ST elevation, echocardiography revealed mild aortic valve regurgitation without left ventricular asynergy and pericardial effusion. Furthermore, laboratory findings revealed anemia (hemoglobin level, 8.1 g/dL) and hyperfibrinolysis (fibrin/fibrinogen degradation product level 67.6 μg/mL, d-dimer level 33.8 μg/mL). Based on these findings, the patient was diagnosed with acute type A aortic dissection with right limb ischemia because of right common iliac artery occlusion. Accordingly, we recommended repair of type A aortic dissection. However, we performed femorofemoral shunting before repair of type A aortic dissection to prevent complications of prolonged limb ischemia.
After cannulating the bilateral radial arteries under ultrasonographic guidance for monitoring of the arterial blood pressure, we induced general anesthesia and performed intubation with a 6.5-mm cuffed endotracheal tube using a video laryngoscope. We fixed the endotracheal tube at 19 cm after verifying the position with fiberoptic scope. Then, we cannulated the right jugular vein under ultrasonographic guidance for central venous access and pressure monitoring. Of note, narrow pharyngolarynx and short neck rendered transesophageal echocardiography impossible. We maintained anesthesia with propofol, rocuronium, and remifentanyl infusion.
Despite exposing common femoral arteries, these had a 9-mm diameter and could not be dissected, and the right femoral artery had no pulsatile flow. We antegradely cannulated a 4-French (Fr) sheath at the right common femoral artery. Then, we shunted from the right radial artery to the right femoral artery to ensure blood supply to the right lower limb and minimize ischemia-reperfusion injury until cardiopulmonary bypass (CPB) was established.
The chest was opened uneventfully through median sternotomy with relatively stable hemodynamics. The patient’s heart and lung were normal in size and appearance. After heparinization (300 IU/kg) and obtaining an activated clotting time (ACT) > 400 s, we initiated CPB using 16-Fr arterial cannula insertion from the left femoral artery and 28-Fr cannulas for the superior and inferior vena cava. After establishing CPB, we supplemented flow in the right lower extremity through the sheath from a sidearm of the left femoral arterial cannula and proceeded with hemiarch reconstruction (Fig. 2). CPB flow rates maintained a cardiac index of 2.0–2.5 L/min/m2. We placed a vent in the right upper pulmonary vein once the heart started to fibrillate, followed by hemoconcentration through the procedure. We used moderate systemic hypothermia to a target temperature of 27 °C. After initiating circulatory arrest at 27 °C rectal temperature, we initiated antegrade selective cerebral perfusion following the ascending aortotomy. Then, the dissection flap with a primary tear was identified in the mid-to-proximal ascending aorta. Hemiarch repair with a one-branched J Graft Shield Neo 26-mm Dacron graft (Japan Lifeline, Tokyo, Japan) was performed. Upon completion of the hemiarch repair, although the patient demonstrated the pulsatile flow in both femoral arteries, the low-flow state existed in the right lower extremity, leading us to perform a femorofemoral crossover bypass. The patient was shifted to the surgical intensive care unit in stable condition. Her immediate postoperative course remained uneventful, and she recovered without neurological or motor deficits in the bilateral lower extremities. A postoperative histological examination of the removed aortic wall revealed no specific findings, such as cystic medial necrosis or infiltration of the inflammatory cells, in an aortic wall. Postoperative CT scan revealed antegrade perfusion of the right common iliac artery; however, the femorofemoral crossover bypass was occluded (Fig. 3). Finally, on postoperative day 41, the patient was discharged to a geriatric health service facility (Fig. 4).
