Causes and management of aortic valve regurgitation after aortic valve reimplantation

Valve-Sparing Aortic Root Replacement State-of-the-Art Review, Part II: Surgical Techniques

Aortic valve disease is common, and valve-preserving operations are preferred whenever possible. Valve-sparing aortic root replacement (VSRR) has become an important tool for managing aortic root pathology in children and adults. The learning curve for this operation is challenging, but with increasing experience and technical modifications, early and late outcomes continue to improve. Durable long term results vary based on underlying anatomy, pathology, and patient selection, as well as surgeon expertise. Part II of this VSRR State-of-the-Art Review article provides technical pearls related to VSRR.

Biomechanical evaluation of aortic regurgitation from cusp prolapse using an ex vivo 3D-printed commissure geometric alignment device

BACKGROUND

Aortic regurgitation (AR) is one of the most common cardiac valvular diseases, and it is frequently caused by cusp prolapse. However, the precise relationship of commissure position and aortic cusp prolapse with AR is not fully understood. In this study, we developed a 3D-printed commissure geometric alignment device to investigate the effect of commissure height and inter-commissure angle on AR and aortic cusp prolapse.

METHODS

Three porcine aortic valves were explanted from hearts obtained from a meat abattoir and were mounted in the commissure geometric alignment device. Nine commissure configurations were tested for each specimen, exploring independent and concurrent effects of commissure height and inter-commissure angle change on AR and aortic cusp prolapse. Each commissure configuration was tested in our 3D printed ex vivo left heart simulator. Hemodynamics data, echocardiography, and high-speed videography were obtained.

RESULTS

AR due to aortic cusp prolapse was successfully generated using our commissure geometric alignment device. Mean aortic regurgitation fraction measured for the baseline, high commissure, low commissure, high commissure and wide inter-commissure angle, high commissure and narrow inter-commissure angle, low commissure and wide inter-commissure angle, low commissure and narrow inter-commissure angle, wide commissure, and narrow commissure configurations from all samples were 4.6 ± 1.4%, 9.7 ± 3.7%, 4.2 ± 0.5%, 11.7 ± 5.8%, 13.0 ± 8.5%, 4.8 ± 0.9%, 7.3 ± 1.7%, 5.1 ± 1.2%, and 7.1 ± 3.1%, respectively.

CONCLUSIONS

AR was most prominent when commissure heights were changed from their native levels with concomitant reduced inter-commissure angle. Findings from this study provide important evidence demonstrating the relationship between commissure position and aortic cusp prolapse and may have a significant impact on patient outcomes after surgical repair of aortic valves.

Failures of Valve-sparing Aortic Root Replacement using the Root Remodeling Technique

BACKGROUND

Valve failure may occur after valve-sparing aortic root replacement. Little is known about the exact mechanisms of failure. We analyzed our experience with reoperations after aortic root remodeling to determine failure modes, operative risk, and long-term outcome.

METHODS

Between 11/1995 and 12/2019, 1084 patients were treated by root remodeling. Of these, 54 (49 male, 8 to 79 years) underwent reoperation for valve failure (1 week to 16 years postoperatively). The indications for reoperation were aortic regurgitation (n=39), aortic stenosis (n=6), endocarditis (n=7), or ventricular septal defect (n=2). The main causes of valve failure were cusp repair failure (n=29), endocarditis (n=7), and cusp retraction (n=8). The patients were treated by valve replacement (n=40) or cusp repair (n=14). In 6 individuals, combined replacement of valve and root was performed. All 54 patients were followed (mean 69±54 months after reoperation), 1 patient was lost to follow-up.

RESULTS

No patient died in hospital or developed atrioventricular block; twelve patients died late with 10- and 15-year survival of 87%±5.1% and 64%±10.6%. Of the 14 patients who underwent repeat cusp repair, 7 (50%) are still alive with stable valve function, 17 months to 15 years after their reoperation. Eleven patients required a second reoperation leading to a freedom from repeat reintervention of 68%±9.7% at 15 years.

CONCLUSIONS

The main causes of failure of root remodeling are cusp related. Reoperations can be performed with low morbidity and mortality. In selected patients, isolated cusp repair may be an option.

Long-term experience with valve-sparing root reimplantation surgery in tricuspid aortic valve

Objective

To analyze our long-term experience with valve-sparing reimplantation technique in treating aortic root aneurysm, aortic regurgitation, and aortic dissection in patients with tricuspid aortic valve.

Methods

Between March 1998 and October 2018, 303 consecutive patients underwent valve-sparing reimplantation in our institution. The mean age of this cohort was 52.9 ± 15 years. Time to event analysis was performed with the Kaplan-Meier method. Risk of death, reoperation, and aortic regurgitation (AR) recurrence were analyzed using the cox-regression method.

Results

In-hospital mortality was 1% (n = 3) of which two were admitted for acute aortic dissection. Median follow-up was 5.81 years ([IQR]: 2.8-10 years). Thirty-nine patients (14.4%) died during follow-up. At 5 and 10 years, overall survival was 92 ± 2%and 75 ± 4.9%, respectively. Seventeen patients required late aortic valve reoperation. Freedom from valve reoperation was 95 ± 2% and 90 ± 3%. Freedom from AR > 2+ and AR > 1+ at 10 years was 91 ± 4% and 71.5 ± 4.6%, respectively. Significant multivariate predictors of death included age, New York Heart Association dyspnea class (NYHA), type A acute dissection (TAAD), and preoperative left ventricular end-diastolic diameter (LVEDD). Significant multivariate predictors of AR recurrence included indication for surgery, previous cardiac surgery, and presence of preoperative AR. Freedom from events like major bleeding, thromboembolic events, and infective endocarditis at 10 years were 97%, 98%, and 96%, respectively.

Conclusions

Aortic valve-sparing with the reimplantation technique has been performed for over two decades in our institution, and the results in patients with tricuspid aortic valve (TAV) are excellent in terms of survival and freedom from valve-related adverse outcomes including valve reoperation. These results continue supporting the use of valve sparing root replacement using the reimplantation technique (VSRR) in patients with aortic aneurysm, irrespective of whether they have preoperative AR or not. VSRR is safe, durable, and reproducible, but further follow-up, well into the second decade is still necessary.

Early and long-term outcomes for patients undergoing reoperative aortic root replacement

OBJECTIVES

There are limited data on aortic root replacement (ARR) in patients with previous cardiac surgery. We analysed short-term and long-term results for patients with ARR after previous cardiac surgery.

METHODS

From September 1995 to April 2015, 130 patients underwent reoperative ARR. Fifty patients had undergone ARR previously (Group I), and 80 had been treated by isolated aortic valve repair or replacement (Group II). The primary indications for surgery were active endocarditis in 65 patients (50%), aneurysmatic root dilatation in another 37 (28.5%) and valve failure in 27 (20.8%).

RESULTS

Overall hospital mortality was 10% (n = 13). Survival at 10 and 15 years was 59.4% and 40.6%, respectively. Survival at 10 and 15 years was 71.5% and 62.5% in Group I and 56.2% and 35.4% in Group II, respectively (P = 0.14). Survival was significantly worse in patients operated for active endocarditis (23.7% vs 56.4% at 15 years; P < 0.001). Inferior 15-year survival was also observed for patients requiring concomitant surgery for cardiac comorbidities (10.5% vs 48.7%; P = 0.003) and in the elderly (≥60 years; 26.8% vs 59.5%; P < 0.001). Ten-year survival was best in patients after valve-preserving root replacement (100%). Multivariable analysis revealed age, active endocarditis and concomitant surgery for cardiac comorbidities as risk factors for death.

CONCLUSIONS

ARR after previous cardiac surgery can be performed with reasonable short-term and long-term survival. It is inferior in patients with active endocarditis or cardiac comorbidities and in the elderly. In these scenarios, less invasive procedures may be considered where applicable.

Transthoracic echocardiography for selection of tubular graft size in David reimplantation technique

OBJECTIVES

Selection of tubular graft size during David reimplantation technique for aortic root dilatation is based on perioperative leaflet height measurements. The present study evaluated whether transthoracic echocardiography (TTE)-based algorithms may help in selecting the graft size preoperatively.

METHODS

Thirty patients (52 ± 11 years old, 73% men) who underwent David reimplantation technique were evaluated. The implanted graft size was based on the David's formula. Leaflet height [diameter = 1.1 × ((2 × 2/3 × leaflet height) + 2)), leaflet length (diameter = ((2 × 2/3 × leaflet length) + 2)] and leaflet area [diameter = 0.8 × ((2 × √(total leaflet area/π)) + 2)] TTE-derived formulas were retrospectively developed. The percentage of under- or oversized implanted grafts was calculated and the association between the adequacy of graft sizing using TTE-derived formulas and the incidence of residual aortic regurgitation (AR) was evaluated retrospectively.

RESULTS

The incidence of postoperative mild residual AR was 23%. The true diameter of the inplanted graft was oversized based on leaflet height in 15 (50%) patients, based on leaflet length in 13 (43%) patients and based on leaflet area TTE-derived formula in 11 (37%) patients. The incidence of mild AR was significantly lower in undersized grafts compared with oversized grafts based on leaflet length TTE-derived formula (6 vs 46%, P = 0.032) and leaflet area TTE-derived formula (5 vs 55%, P = 0.009).

CONCLUSIONS

In patients undergoing David reimplantation technique, grafts considered undersized according to the leaflet length or leaflet area TTE-derived formula were associated with less incidence of residual AR than patients with oversized grafts.

Aortic valve repair--current status, indications, and outcomes

Aortic valve repair is a new development with old roots. In the past 20 years, marked progress has been made in understanding the normal anatomy of the aortic valve and the interrelation between cusps and root. Aortic dilatation is the single most frequent pathogenetic factor in aortic regurgitation, accompanied by cusp pathology, that is, prolapse or congenital anomaly in most industrialized countries. Frequently, aortic and cusp pathology coexist. Different operative techniques have been established for correction of aortic and cusp pathology. Experience has shown that the combined application of repair procedures will lead to good results if normal valve and cusp configuration is achieved. Some congenital anomalies may require design alteration of the aortic valve. Low-operative mortality rates have been reported consistently. When adequate repair durability is achieved, the incidence of valve-related complications is lower than what has been reported for valve replacement. Aortic valve repair is currently in transition from surgical improvisation to a reproducible operation and an option for many patients with aortic regurgitation. Current research focuses on some special aspects, such as stabilization of the basal ring, ideal material and technique for cusp replacement, and more objective information on ideal valve configuration.