Aortic valve reimplantation: unquestionably a long-term solution?

In the past 2 decades valve-preserving surgery has received marked interest in the cardiac surgical community. Soon after the first publication on aortic valve reimplantation [1], the Hannover group started their own series, originally initiated by myself. They now publish their long-term results with follow-up data covering 3 decades and generally good results [2]. Apart from being probably the largest series of aortic valve reimplants, the paper essentially sends 2 messages: Good results can be obtained with valve stability over 25 years, and the technique can be applied in a variety of instances, including bicuspid aortic valves or acute aortic dissection. Because different surgeons were involved over time, the authors argue that the technique is reproducible. The report gives the impression that the concept is ready for general use.

The first point confirms the concept, and the second does not come as a surprise. There is a caveat, however, regarding valve function. In the hands of the pioneer of this operation, an increasing incidence of aortic regurgitation (AR) was observed in the second decade [3]. This finding is difficult to judge in the current report, mainly because the echocardiographic information is incomplete. Apparently, 8% of the patients had no documented early postoperative echocardiogram; at the last follow-up, 24% had variable degrees (more than minimal) of regurgitation, but the authors did not specify further or analyse it in a time-dependent fashion. It is unclear how many of the deceased patients developed recurrent regurgitation, which may have contributed to the late deaths.

The fact that the operation can also be applied in acute dissection, with bicuspid aortic valve morphology, or with limited access, is not new. To provide a learning benefit, however, the article should ideally tell us what to pay attention to, what not to do and why certain procedures should be avoided. Failures after this form of surgery are usually cusp related [4], and selection of a suitable substrate and precise conduction of the operation are crucial components. To make this operation reproducible and applicable to a large number of patients, these details should be as specific as possible.

The current paper provides few details about acceptable valves. The authors state, “significant sclerosis, retractions or fenestrations are usually regarded as contraindications”. It is unclear how the authors define sclerosis or retraction. Do they mean all fenestrations, or only the ones involved in cusp prolapse? To have a general idea how selective they have been, it would be helpful to know what proportion of patients with AR and root aneurysm were treated by valve preservation.

In describing the surgical technique, the authors correctly emphasize the importance of avoiding commissural retraction. For intraoperative control of the valve form, they rely on visual assessment only, which is subjective and has been shown to produce inconsistent results in the hands of others [5]. To enhance reproducibility, the use of more objective criteria would be helpful, such as measurement of geometric and effective height [6–8]. Even though 24 surgeons contributed to the current series, it is unclear whether their long-term results differed and why.

In addition, it would have been important to analyse the failures more clearly—both those who required reoperation and those who are being followed because of recurrent regurgitation. After all, we generally learn more from failures than from successes. Was the reason for recurrent AR more likely persistent cusp prolapse or rather retraction? How often did it occur in those who came for reoperation, those who died or those who currently have more than minimal AR? I agree with the authors’ statement, “we think that cusp repair for prolapse is an important step to ensure durable long-term performance of the valve”, but it would have been helpful to see their own evidence for this.

In summary, the current paper confirms that aortic valve reimplantation can be durable for up to 3 decades. Many questions, however, remain unanswered. To improve the performance of such operations, we must continuously and carefully analyse the results in detail, attempting to find answers to the questions that arise. Such a detailed analysis is necessary to improve the results in the hands of experienced surgeons and increase its reproducibility in the hands of less experienced colleagues.

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