Aortic valve repair has emerged as an appealing alternative to prosthetic replacement in younger patients by avoiding the need for anticoagulation that mechanical prostheses necessitate. Although a safe procedure, repair failure remains the most common complication. Understanding the mechanisms associated with valve insufficiency during follow-up or reintervention is critical for accurate patient selection and optimal surgical indication, aiming for the most durable repair possible. Potential failure mechanisms have been studied in bicuspid aortic valves and in aortic root remodeling or reimplantation, including cusp prolapse, leaflet retraction, and annular dilation. However, these mechanisms have not been analyzed in isolated repairs on tricuspid aortic valves.

This retrospective study aimed to evaluate mid-term results of isolated aortic valve repair in tricuspid valves at one of the world’s largest centers for aortic valve repair. A total of 264 patients were analyzed from a registry over 17 years, with a median echocardiographic follow-up of nearly six years (5.9 ± 3.6 years) and a clinical follow-up of almost seven years (6.8 ± 3.6 years). A noteworthy aspect of the study was the introduction of a classification based on cusp prolapse or retraction as a cause of aortic insufficiency. However, retraction in this context was not defined as fibrosis and/or free margin traction causing residual insufficiency but rather as any cusp with a geometric height under 19 mm. Survival, reintervention, and the incidence of significant aortic insufficiency during follow-up were analyzed. Ten-year survival was 76.7% ± 3.5%, significantly lower in patients who underwent concomitant coronary or mitral repair with the aortic valve procedure. Among those with isolated repair, ten-year survival was much higher (92.3% ± 2.7%). In subgroup analysis, the use of subcommissural plication was associated with worse survival (p = 0.044). Conversely, the use of pericardial patches in repair did not significantly impact survival (p = 0.088). Intraoperative effective height measurement correlated with improved survival (p < 0.001). Regarding reintervention-free outcomes, the authors recorded a ten-year rate of 73.3% ± 4.2%, with 41 (16%) patients requiring reintervention. Causes of reintervention included prolapse in 10 cases, retraction in 22, both phenomena in 4, and endocarditis in 5 patients. In these patients, various techniques—including subcommissural plication, annuloplasty, or pericardial patch—showed no significant differences in reintervention risk. In the cohort, 48 (18%) developed significant aortic insufficiency (grades 3 or 4+) during follow-up. Analysis showed a ten-year residual insufficiency-free rate of 66.9% ± 5.2%. Subgroup analysis revealed that patients whose repair mechanism was prolapse had lower rates of aortic insufficiency during follow-up compared to those with cusp retraction as the cause (log rank = 0.036). Again, none of the techniques showed an improvement in prognosis in these patients.

The authors conclude that aortic valve repair in tricuspid valves offers good long-term survival. Repair of cusp retraction had lower durability than prolapse repair. Intraoperative measurement of effective height was associated with improved survival in tricuspid aortic valve repair.

COMMENTARY:

Despite efforts in recent years by Schäfers’ group in Homburg to standardize aortic valve repair, little is known about short- and mid-term outcomes of this technique in tricuspid aortic valves. Unlike bicuspid valves, tricuspid valves have less associated annular ectasia, often leaving diseased cusps as the main cause of valve insufficiency, making success highly dependent on the surgeon’s expertise.

The heterogeneity of the sample presented in this study may dilute the results. In this case, the high number of concomitant surgeries might adversely affect survival. Isolated aortic valve repair yields nearly 93% ten-year survival, superior to many series of aortic prosthetic valve replacements, which typically show around 80% survival at ten years.

Regarding residual aortic insufficiency, results indicate a nearly 67% ten-year freedom from residual insufficiency. The mean aortic annulus diameter is high (26 mm), including two patients with Marfan syndrome. Some cases might have benefited from root reimplantation or remodeling, though aortic root measurements are not provided for confirmation. The residual insufficiency rates could be partially explained by the cohort’s patient characteristics. Tables reveal a high number of repairs deemed complex, with 110 patients receiving pericardial patches and 49 showing leaflet retraction defined as geometric height under 19 mm. In many published series, these patients would not be candidates for valve repair.

The most relevant information arises from the surgical findings in redo patients. The repairs that failed most frequently were those with retracted cusps, and annuloplasty showed no effect on residual insufficiency. Most repair failures were due to cusp retraction. Notably, the use of pericardial patch or subcommissural plication was not associated with higher reintervention rates in these valves. Longer follow-up is required to determine if both curves significantly diverge over time.

Aortic valve repair in complex scenarios, such as retraction or combined prolapse and retraction, yields poorer outcomes. In such cases, aortic valve replacement is likely the best option. Findings like those published by the SPAVALVE group reinforce the feasibility of offering biological prostheses at younger ages, thereby avoiding anticoagulation risks in young patients. Despite advances in aortic valve repair, tricuspid aortic valves remain surgically challenging even in specialized centers.

REFERENCE:

Anand J, Schafstedde M, Giebels C, Schäfers HJ. Significance of Effective Height and Mechanism of Regurgitation in Tricuspid Aortic Valve Repair. Ann Thorac Surg. 2023 Feb;115(2):429–35. doi: 10.1016/j.athoracsur.2022.05.055.

Rodríguez-Caulo EA, Blanco-Herrera OR, Berastegui E, Arias-Dachary J, Souaf-Khalafi S, Parody-Cuerda G, et al. Biological versus mechanical prostheses for aortic valve replacement. Journal of Thoracic and Cardiovascular Surgery. 2023 Feb 1;165(2):609-617.e7. doi: 10.1016/j.jtcvs.2021.01.118.