Aortic Valve Repair: A Real Challenge to Cardiac Surgery
Reconstruction of the aortic valve has been rarely performed during a half-century of cardiac surgery. The aortic valve repair was reported early after the beginning of open heart surgery by Albert Starr [1] and Frank Spencer [2] in congenital heart diseases. The satisfactory short and long-term results with valve replacements, together with the limited knowledge of the aortic root function were the main causes of the lack of interest for this surgical alternative. Paul Wojewski recently pointed out [3]: “We have lost our way in aortic valve surgery. We have made a lot of valves but we have never followed in general the principals dictated by nature”. Few surgeons in the world investigated the anatomy and complex physiology of the aortic valve, and later they have tried to apply their research findings to the surgical field. Magdi Jacoub and Tirone David have developed surgical techniques to spare the aortic valve when the aortic root replacement is mandatory, with very encouraging and predictable mid- and long-term results in a significant number of patients. Their original techniques and later modifications have widely accepted and they are now used by a growing number of surgeons.
Surgical reconstruction of the acquired aortic valve regurgitation has been explored with unpredictable results. During the eighties, Alain Carpentier [4,9] and Carlos G. Duran [5,7,8,11,12], at our Institution in Santander, have introduced different techniques to repair the aortic insufficiency with satisfactory mid-term results. During the last decade, several publications demonstrated an increasing interest with this challenging surgery. However, a variety of reconstructive techniques were used, without a clear categorization of the indications, or a separate analysis of the durability of each surgical technique.
Aortic regurgitation is produced by lack of coaptation of the leaflets due to prolapse of one or all cusps, the dilatation of the aortic annulus and/or the sinotubular junction, the damage or destruction of one leaflet, or the structural modification of the cusps. As John A. Carr and Edward B. Savage from Chicago have recently reported in an elegant review [6], the types of reconstructive technique used, mainly depends on the surgeon preferences. In general, these techniques could be classified as followed:
For isolated annular dilatation (non-aneurysmatic dilatation)
For leaflet damage or destruction
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Leaflet simple suture
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Pericardial patch repair
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Pericardial extension
For leaflet prolapse
For leaflet retraction
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Lunulae unrolling
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Lunulae shaving
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Commissurotomy
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Pericardial extension
Duran et al [7] have reported the indications and limitations of aortic valve reconstruction, with the different repairs. Most of their patients did not required anticoagulation prophylaxis, only receiving antiplatelet drugs, with a low incidence of thromboembolic events (less than 1%).
Postoperative valve-related complications after aortic valve repair were low as shown in a meta-analysis of 761 patients [6]. The small incidence on thromboembolic events (1%) after aortic valve repair in patients without anticoagulation encourages for a persistent investigation on this surgical approach. Infective endocarditis is also low (average: 0.7%) over a mean follow-up of 4 years, significantly lower than the reported incidence after aortic valve replacement with bioprostheses. This incidence is appreciably higher (2.4%) after aortic cusp pericardial extension techniques [6].
Durability after aortic valve repair still remains uncertain. The reported 10-year freedom from reoperation rate was 64%, with a reoperation rate of 7.8%. This fact represents the determining factor in selecting this surgical alternative. Different authors agreed that the clinical outcome is significantly worse for the repaired rheumatic and bicuspid aortic valves than for the other etiologies, with higher recurrence and reoperation rates. Early causes of failure were suture dehiscence, incomplete repair, pericardial patch tear or detachment. Late failures were due to progression of the disease, pericardial patch or strip tissue degeneration (tear, fibrosis, retraction or calcification) [13]. Aortic leaflet extension with a strip of glutaraldehyde-treated autologous pericardium was used by Duran et al. [8] in patients with severe valve incompetence, but not long-term results have been described. Ahn et al. [10], from South Korea, have reported their experience in a group of 34 patients with pericardial leaflet extension technique, and only 8 patients were free from aortic valve regurgitation, but 93% of patients are free from reoperation one year after surgery. They concluded that a long-term follow-up study will be necessary to evaluate the durability of this reconstructive procedure.
Few years ago, we explored [14] whether or not the aortic valve repair was safe in patients with non-severe rheumatic aortic valve disease during other valvular procedures. In a group of 53 patients who underwent aortic valve repair with different repair techniques at the time of mitral or mitro-tricuspid valve surgery, only 12.7% were free from aortic valve structural deterioration 22 years after surgery; so, we concluded that the concomitant aortic valve repair did not seem appropriate. However, Al-Halees et al. [15] have later reported that, in their experience, repair of associated moderate aortic valve incompetence is worth considering even in predominantly young rheumatic population. They were more optimistic about the validity of this surgical approach, on a similar group of patients with a freedom from reoperation of 63.4% at 8-year follow-up. These authors pointed out that the lack of TEE in our series could explain the differences in our clinical outcomes.
Further analysis are necessary, separating the different etiologies, valve pathologies, and particularly the types of aortic valve repair technique used. Aortic valve repair will provide the patients with a better quality of life, no need for permanent anticoagulation, a lower incidence of thromboembolic events, endocarditis, and other valve-related complications. However, the durability of repair is still unclear, so it will require additional attention in order to establish the indications, to validate techniques, and above all to assess the durability of aortic valve repair in larger series of patients.
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