Can the bicuspid aortic valve be spared? The con position, with caveats and nuances.

The new (2010) American Heart Association/American College of Cardiology guidelines1 present a dilemma to the cardio-aortic surgical community regarding bicuspid aortic valve (BAV) when found in combination with pure aortic insufficiency (AI) (no aortic stenosis) and with proximal aortic aneurysmal disease. The new guidelines recommend resection at 5.0 cm, and there are additional indications for resection at 4.5 cm in patients who have genetically triggered aortic conditions. The denomination inherent in this general recommendation will affect many patients, including a significant number of “4.5 to 5.0 cm” BAV patients who have proximal aortic aneurysms and physiologically normal valves, near-normal valves, valves with pure AI, or eminently repairable cusps. As a result, the task and challenge facing the cardio-aortic surgical community is to spare and repair these valves when possible and when appropriate. Most insufficient BAVs present with dilation of the annulus and proximal aorta, cusp prolapse, and eccentric AI. This presentation is a combination of aortic and primary leaflet pathologic conditions (Fig. 1).2 Fig. 1 Repair-oriented functional classification of bicuspid aortic valve aortic insufficiency (AI) as conceived by El Khoury and the Brussels group.2 The highlighted type Ib and type II bicuspid aortic valve combination is the most common combination ... The general principles of BAV repair are as follows: Create free-margin equality of the leaflets to treat the cusp prolapse. This will require plication or resection of excess leaflet tissue. Release the raphe if that is anatomically indicated in order to improve leaflet mobility. Reduce and stabilize the annulus (ventriculo-aortic junction). The bottom line is that any purely insufficient valve with enough leaflet surface area can be repaired. So the main question is: How dogmatic should we be with this approach? The reconstructive strategy is decided on the basis of 3 general presentations of BAV with pure AI: Repairable BAV cusps with annular dilation and proximal thoracic aortic aneurysm. The treatment is a valve-sparing aortic root reimplantation procedure, which has very satisfactory mid-term results with very reasonable survival, freedom from reoperation, and freedom from ≥ 2+ AI, according to multiple reports.3–5 Repairable BAV cusps with annular dilation ≥28 mm (an abnormal annular dimension) without significant proximal aortic dilation. This second condition—in which the “best” aortic valve procedure is an aortic root procedure—presents a major dilemma to the reconstructive heart-valve surgeon. It carries with it a general contraindication to classic BAV repair techniques, because recent data show significant short- and mid-term failure rates with simple subcommissural (or subannular) annuloplasty (SCA) combined with classic cusp-repair techniques (Fig. 2).3,5,6 The reports show failure—that is, freedom from recurrent AI >2+ of only 34% through 62% at 5 years. In addition, freedom from reoperation under this condition is reportedly as low as 50% out to 9 years.3,5,6 Fig. 2 A) Comparison of aortic insufficiency (AI) recurrence after cusp repair combined with simple subcommissural annuloplasty (repair group: 62% ± 10%) versus cusp repair combined with root reimplantation (reimplantation group: ... Repairable BAV cusps with annular dilation ≤27 mm (a normal annular dimension) without significant proximal aortic dilation. On the other hand, patients with annular dilation ≤27 mm have generally excellent mid-term results using SCA—no need for reimplantation, >90% freedom from AI >2+, and a very low risk for reoperation in the mid term.5 This is secondary to a more stable aortic annulus, which at the time of the initial procedure is normal, or near-normal, in diameter (Fig. 3).7 Fig. 3 Graph shows excellent survival outcomes of bicuspid aortic valve patients after the Bentall procedure at the 12-year follow-up, particularly when compared with life expectancy of the age- and sex-matched population. In addition, when the surgeon is presented with a BAV with AI and reduced leaflet surface area (Sievers' type 2 BAV), the only reconstructive option is patch augmentation of the leaflet to achieve a greater coaptation zone. This approach has been ineffective, for it is associated with poor mid-term outcomes and freedom from reoperation of only 50% at 5 years.6 The backdrop for the argument to selectively apply BAV repair techniques in patients with AI with or without proximal aortic aneurysm is the excellent long-term survival rate after the Bentall procedure in BAV. Survival outcomes with this surgical strategy are similar to those of an age- and sex-matched segment of the U.S. population at 12-year follow-up.7 Furthermore, the major aversion to a tissue-valve solution in a younger patient is mitigated by the potential for a subsequent transcatheter valve-in-valve procedure that would, in theory, add another 10 years to the tissue-valve solution for patients undergoing the Bentall procedure. In summary, BAV repair for aortic valve insufficiency, with or without root aneurysm, is a very satisfactory operation in selected patients. However, there are several significant, relative contraindications to BAV repair. The results in these circumstances are simply not satisfactory and do not stand up to in-depth review. These contraindications include 1) calcification of the valve leaflets, 2) substantial fenestration of the valve leaflets, 3) the need for patch augmentation, and 4) the obvious dilemma of the large aortic annulus (≥28 mm), within a root of normal diameter and geometry, that requires a more complicated full-root operation for what is essentially isolated cusp disease. At present, the data for simple SCA combined with cusp repair in the population described above simply do not stand scrutiny. The results in patients with a relative contraindication to valve repair, as listed above, do not compare to the excellent long-term results found in composite-graft root reconstruction or in bioprosthetic root surgery—especially given the potential for transcatheter aortic valve-in-valve rescue, which theoretically supplies an even longer-term tissue bioprosthetic solution.