2-3. Outcome and follow-ups
The patient had no major postoperative complications and was discharged on postoperative day 24. At follow-up one year after surgery, there was no aneurysmal lesion on CT, and she was well and had no complications.
Discussion
SVA is a rare congenital or acquired disease. Congenital cases may be associated with ventricular septal defect or bicuspid aortic valve. Acquired cases result from infections, such as syphilis, tuberculosis, and bacterial endocarditis, as well as trauma, aortitis, and connective tissue diseases, such as Marfan syndrome.1,2,4,5
SVAs mostly originate from the right sinus (65–85% cases); non-sinus origin is observed in 10–30% cases, and left sinus origin is even rarer, accounting for less than 5% cases.1,2
Similar to other aneurysms, an unruptured SVA is often asymptomatic; however, as the aneurysm grows, it causes difficulties in adjacent structures. When an unruptured left SVA grows, it can cause chest pain due to acute coronary syndrome caused by the compression of the left coronary artery by the aneurysm.6–9
Aortic regurgitation caused by aortic annulus enlargement and/or cusp prolapse is often associated with SVA. A non-ruptured SVA is associated with aortic regurgitation in 30–50% cases.5
Symptomatic aneurysms, including ruptured ones, are indications for surgical repair; however, in the case of unruptured and asymptomatic SVA, the indication and timing of surgery should be determined based on the evaluation of the risk of SVA, which is calculated by determining aneurysm size, grade of aortic regurgitation, and risk of thrombus formation.10,11
Patch closure has been used in many cases for SVAs. Coronary artery bypass grafting and/or prosthetic valve replacement may be performed depending on the lesion. Depending on the condition of the aortic root, such as multiple sinus lesions, aortic root replacement with a prosthetic valve or a valve-sparing procedure can be selected.9,10
In addition to the risk of rupture caused by the large saccular aneurysm protruding into the extracardiac space, the risk of embolism caused by a thrombus in the aneurysm and the risk of myocardial ischemia caused by coronary artery compression, we determined that surgery was necessary. The patient tolerated the operation without any major complications despite her advanced age. Similar cases of aortic root replacement using a biological prosthetic valve or a valve-sparing aortic root replacement have been reported.9,10 In this case, because the lesion was localized in the left sinus, we decided to reconstruct only the left sinus with an artificial patch. Coronary artery bypass grafting was performed to prevent cardiac ischemia.
In aortic regurgitation, if the valve cusps are preserved under normal conditions, it is important to correct the enlargement of the aortic valve annulus and the dilated sinotubular junction to control aortic regurgitation.12,13 In this case, moderate aortic regurgitation was observed before surgery, and the left aortic annulus was stretched and unstable owing to the aneurysmal wall defect in the left sinus, but no major abnormalities were observed in the cusp. The left sinus and aortic annulus were formed with a patch, and the sinotubular junction was ring-fixed with a felt strip. Aortic regurgitation improved with these procedures.
This is a rare case of SVA in an older patient aged >80 years. In a literature review by Nguyen et al. covering reports from 2000 to 2020, there was only one other case of an unruptured SVA in a patient aged >80 years.4,5 It is preferable for older patients to have an SVA treated with a less invasive surgical procedure if the lesion is localized, as in this case.
If aortic enlargement, multiple dilated sinus lesions, marked aortic annular enlargement or severe aortic regurgitation caused by aortic cusp lesions had been observed, aortic root replacement with a biological prosthetic valve would have been performed.
Conclusion
In the extremely rare case of an unruptured giant left SVA in an older patient, patch repair and coronary artery bypass grafting can be performed with satisfactory results.
To avoid the risk of acute coronary syndrome, coronary artery bypass should be performed aggressively if extrinsic compression of the left coronary artery is obvious. Aortic valve replacement may be avoided by correcting the aortic annular enlargement and correcting the dilated sinotubular junction if aortic regurgitation is complicated, as in this case.