Following a median sternotomy, cardiopulmonary bypass was initiated with aortic and single atrial cannulation. Following antegrade cardioplegic arrest, a transverse aortotomy was made and aortic valve was inspected. As opposed to preoperative echocardiography, aortic valve was quadricuspid with mild thickening and calcification. The valve had one large, two intermediate and one small cusp (Type D in Hurwitz and Roberts' anatomical classification). Accessory cusp was located between the right and left coronary cusps (Figure 1). There was no abnormality regarding coronary arteries. Native valve was excised and a 25 mm mechanical bileaflet valve was implanted. Postoperative period was uneventful and he was discharged in the fifth postoperative day. Followup echocardiography revealed that the valve was functioning well, the left ventricular dimensions and functions were preserved.

Figure 1: Accessory cusp (AC) located between right coronary cusp (RCC) and left coronary cusp (LCC). Note that non-coronary cusp (NCC) is large, RCC and LCC are intermediate, and the accessory cusp is small (Type D).

Hurwitz and Roberts' anatomical classification is the most commonly used systematization tool, which classifies QAV into seven types depending on the relative size of the valve leaflets (Type B is the most common). The most common positions of the accessory cusp is between the right and non-coronary cusps.[3] Our case is unique and extremely rare considering the size and positional classification of QAV (Type D and accessory cusp between right and left coronary cusps).

Review of the literature revealed that several cardiac abnormalities may coexist with QAV: anomalies of the coronary arteries, ventricular septal defect, patent ductus arteriosus, and pulmonary valve stenosis. As one of the most common accompanying anomaly, displacement of the coronary ostia has been reported in approximately 10% of cases.[1,3] From the surgical point of view, it is critical to inspect each coronary ostium to prevent ostial obstruction at the time of valve surgery. In our case, no accompanying ostial anomaly was detected.

Another pitfall for surgeon is the downward displacement of the annulus in QAV setting, which may cause complete heart block during valve replacement.[4] In this case, it is recommended to place supra-annular sutures, which lie anteriorly high within the membranous septum. We also placed valve sutures high in between non-coronary and right coronary cusps in our case. The patient had no rhythm disturbances during the postoperative course.

Despite aortic valve replacement for QAV is a traditional treatment of choice for patients with aortic regurgitation, there are only few reports utilizing aortic valve repair techniques (tricuspidization or bicuspidization) in QAV cases.[5] Short-term results are satisfactory; however, further studies and continued follow-up are warranted to elucidate long-term results.

In conlusion, cardiac surgeons keep in mind that QAV is a rare developmental anomaly but possesses low risk in terms of surgical outcome.

Declaration of conflicting interests
The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Funding
The authors received no financial support for the research and/or authorship of this article.

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