MFS is an inheritable connective tissue disorder caused by mutations in the FBN1 gene. Studies have estimated its prevalence to be around 2–3/100,000 individuals, with a variety of manifestations in the ocular, skeletal, and cardiovascular systems [4]. In the present case, the patient’s disorder had been complicated with aortic valve insufficiency and severe scoliosis. Scoliosis occurs in approximately 62% of patients with MFS [5]. Reports have shown that thoracic deformity associated with scoliosis causes respiratory dysfunction due to the disturbance caused by the expansion of thoracic cavity with limited intercostal muscle function. Furthermore, according to the Cobb angle, which is quantified to evaluate the severity of scoliosis, the current patient requires surgical intervention of scoliosis [6]. Although the patient’s respiratory function was normal, prolonged mechanical ventilation was postoperatively predicted.

Cardiac surgery for MFS patients with severe scoliosis can be challenging given the difficulty in determining the appropriate surgical approach for the distorted heart axis. Although studies on mitral valve repair via thoracotomy have been reported, little is known regarding combined cardiac surgery [2]. The current patient required both aortic valve replacement and LAA closure. We expected that median sternotomy would be difficult during aortotomy and that right thoracotomy was not the appropriate approach to the LAA. Therefore, we opted for lower hemisternotomy to safely perform combined cardiac surgery.

Upper hemisternotomy can be useful during cardiac surgery, especially for the treatment of aortic valve surgery [7]. In the current case, lower hemisternotomy was selected since the heart had rotated counter clockwise and the aortic root was positioned lower than usual. In addition, we expected that sternal resection would be extended toward the 2nd intercostal space, requiring thoracotomy in case of an insufficient surgical field for approaching the LAA. Any procedure that required a thoracotomy could be handled effectively using a double-lumen tube. However, sternal elevation using a Kent retractor was helpful in obtaining sufficient space for aortic clamping and delivery of the device for LAA closure. Furthermore, the divided sternum was folded back at the costal arch resembling an open door, which allowed us to better secure the surgical field.

Immature collagen matrix in the rib cartilages has been suggested to cause various pectus deformities, such as pectus excavatum and pectus carinatum, in patients with MFS [8]. Our case presented with pectus carinatum as well as severe scoliosis. Softening of the costal arch due to abnormal growth or elongation in MFS might allow it to be folded back. Surprisingly, the patient had little pain in this area after surgery. Our experience suggested that lower hemisternotomy with the costal arch folded back was less invasive, although it remains to be determined whether this approach can be used in all patients with MFS.