Aortic valve reimplantation in ascending aortic aneurysm: risk factors for early valve failure

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.

A contact model based on the coefficient of restitution for simulations of bio-prosthetic heart valves

A new general contact model is proposed for preventing inter-leaflet penetration of bio-prosthetic heart valves (BHV) at the end of the systole, which has the advantage of applying kinematic constraints directly and creating smooth free edges. At the end of each time step, the impenetrability constraints and momentum exchange between the impacting bodies are applied separately based on the coefficient of restitution. The contact method is implemented in a rotation-free, large deformation, and thin shell finite-element (FE) framework based on loop's subdivision surfaces. A nonlinear, anisotropic material model for a BHV is employed which uses Fung-elastic constitutive laws for in-plane and bending responses, respectively. The contact model is verified and validated against several benchmark problems. For a BHV-specific validation, the computed strains on different regions of a BHV under constant pressure are compared with experimentally measured data. Finally, dynamic simulations of BHV under physiological pressure waveform are performed for symmetrical and asymmetrical fiber orientations incorporating the new contact model and compared with the penalty contact method. The proposed contact model provides the coaptation area of a functioning BHV during the closing phase for both of the fiber orientations. Our results show that fiber orientation affects the dynamic of leaflets during the opening and closing phases. A swirling motion for the BHV with asymmetrical fiber orientation is observed, similar to experimental data. To include the fluid effects, fluid-structure interaction (FSI) simulation of the BHV is performed and compared to the dynamic results.

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.

Outcomes of Valve-Sparing Surgery in Heritable Aortic Disorders: Results from the AVIATOR Registry

OBJECTIVES

Root reimplantation has been the favored approach for patients with heritable aortic disorder (HAD) requiring valve-sparring root replacement (VSRR). In the past few years, root remodelling with annuloplasty has emerged as an alternative to root reimplantation in the general population. The aim of this study was to examine the late outcomes of patients with HAD undergoing VSRR and compare different techniques.

METHODS

Using the AVIATOR registry, data were collected from 5 North American and European centers. Patients were divided in 4 groups according to the technique of valve-sparing used (root reimplantation, root remodelling with ring annuloplasty, root remodelling with suture annuloplasty and root remodelling alone). The primary end-points were freedom from aortic regurgitation (AR) ≥2 and freedom from reintervention on the aortic valve. Secondary end-points were survival and changes in annular dimensions over time.

RESULTS

A total of 237 patients were included in the study (reimplantation= 100, remodelling + ring annuloplasty= 76, remodelling + suture annuloplasty= 34, remodelling alone= 27). The majority of patients had Marfan syndrome (82%). Preoperative AR ≥ 2 was present in 41% of the patients. Operative mortality was 0.4% (n = 1). No differences were found between techniques in terms of postoperative AR ≥ 2 (p = 0.58), reintervention (p = 0.52) and survival (p = 0.59). Changes in aortic annulus dimension were significantly different at 10 years (p < 0.05), a difference that started to emerge 4 after years surgery.

CONCLUSIONS

Overall, VSRR are safe and durable procedures in patients with HAD. Nevertheless, root remodelling alone is associated with late annular dilatation. Addition of an annuloplasty, however, results in similar freedom from AR, reintervention, survival, and changes in annulus size compared to reimplantation.

Two decades of valve-sparing root reimplantation in tricuspid aortic valve: impact of aortic regurgitation and cusp repair

OBJECTIVES

Our goal was to analyse the influence of preoperative aortic regurgitation (AR) on the necessity of cusp repair during valve-sparing reimplantation (VSR). We focused on patients with tricuspid aortic valves (TAV) and evaluated the impact of AR and cusp repair on long-term outcomes.

METHODS

From March 1998 to December 2018, a total of 512 consecutive patients underwent VSR at our institution; of these, 303 had a TAV. The mean age was 53 ± 15 years, and the median follow-up was 6.12 years. The rate and type of cusp repair were analysed based on preoperative AR. Time-to-event analysis was performed, as well as risk of death, reoperation and AR recurrence.

RESULTS

Cusp repair was necessary in 168 (55.4%) patients; the rate rose significantly as AR grade increased (P < 0.001). In-hospital mortality was 1% (n = 3). At 5 and 10 years, overall survival was 92 ± 2% and 75 ± 5%, respectively. Freedom from valve reoperation was 95 ± 2% and 90 ± 3%. Freedom from AR >2+ and AR >1+ at 10 years was 88 ± 4% and 70.4 ± 4.6%, respectively. Independent predictors of death included age, New York Heart Association functional class and type-A aortic dissection. Predictors of AR greater than mild included previous cardiac surgery and severe preoperative AR.

CONCLUSION

In patients with TAV receiving VSR, the necessity of cusp repair increased with the degree of preoperative AR. Preoperative AR and cusp repair do not impact long-term survival and aortic valve reoperation, but severe preoperative AR and multiple cusp repair increase the risk of recurrent moderate-to-severe AR. Overall, cusp repair seems to attenuate the negative impact of preoperative AR for at least 1 decade in a majority of patients.

A Narrative Review of the 2020 Guidelines for Use of Transesophageal Echocardiography to Assist with Surgical Decision- Making by the Cardiac Anesthesiologist in the Operating Room

Transesophageal echocardiography (TEE) has become an integral part in helping to diagnose, manage, and assess interventions in the cardiac operating room. Multiple guidelines have been created by the American Society of Echocardiography for performing a TEE examination for different cardiac pathologies. The operating room can provide unique challenges when performing a TEE examination, which include hemodynamic instability, time constraints, and use of general anesthesia. The Guideline for the use of TEE to assist in surgical decision- making in the operating room recently was published to provide a starting protocol for conducting a TEE examination for different cardiac surgeries and for using the information obtained to interpret and to communicate findings to the surgical team. This present narrative review focuses and expands upon the relevant portions for the cardiac anesthesiologist.

Reimplantation valve-sparing aortic root replacement is the most durable approach to facilitate aortic valve repair

Reimplantation of the aortic valve has been performed for 3 decades, and experience shows that patient selection and meticulous operative technique are crucial to provide excellent clinical outcomes and stable aortic valve function for decades. More than the type of the Dacron graft used for the reimplantation (straight graft or Valsalva graft), we believe that attention to certain technical aspects of this operation is key to a successful and durable aortic valve reconstruction. This article describes the operative procedure as we believe it should be performed based on a learned experience with several hundred cases and summarizes the latest outcomes in a large cohort of patients followed prospectively during the past 3 decades.

Valve-sparing aortic root replacement (David I procedure) in Marfan disease: single-centre 20-year experience in more than 100 patients†

OBJECTIVES

Valve-sparing aortic root replacement (VSARR) is recommended for patients with aortic root dilatation and preserved aortic valve cusp morphology. The durability of VSARR in Marfan patients has been questioned. The aim of our study was to establish the long-term outcomes of VSARR in Marfan patients.

METHODS

Between 1993 and 2015, 582 patients underwent VSARR (David I reimplantation) at our institution. Of these patients, 104 had Marfan disease. Thirteen surgeons performed the procedures in this group. The mean follow-up time was 12 ± 5.4 years (1201 patient-years).

RESULTS

Early mortality was 0.96%, and long-term survival was 91% at 10 years and 76% at 20 years in Marfan patients. Marfan patients had a significantly better survival compared to non-Marfan patients (P < 0.0001). Freedom from aortic-valve reoperation was 86% at 10 years and 80% at 20 years in Marfan patients. The reoperation rate was similar in Marfan and non-Marfan patients (P = 0.60). Morphological perioperative features (untreated prolapse, commissural plasty, cusp plasty and graft size mismatch) predicted long-term mortality (P = 0.0054). Graft size mismatch and untreated prolapse predicted structural valve deterioration (both P < 0.0001). Long-term valve function in event-free survivors was excellent [mean gradient 4.2 (2.9-6.9), 98% aortic regurgitation ≤ mild]. There were no valve-related thromboembolic or bleeding events. The endocarditis rate was 0.96%. Only 17% of the patients were on oral anticoagulants during the follow-up.

CONCLUSIONS

VSARR using the David I reimplantation technique results in excellent long-term outcomes in Marfan patients. We present the longest follow-up period so far. The genetic disease does not affect long-term valve function. The durability of the repair is affected by morphological perioperative criteria depending on surgical expertise, and dedicated training is recommended.

Quantitative three-dimensional echocardiographic analysis of the bicuspid aortic valve and aortic root: A single modality approach

BACKGROUND

Patients with bicuspid aortic valves (BAV) are heterogeneous with regard to patterns of root remodeling and valvular dysfunction. Two-dimensional echocardiography is the standard surveillance modality for patients with aortic valve dysfunction. However, ancillary computed tomography or magnetic resonance imaging is often necessary to characterize associated patterns of aortic root pathology. Conversely, the pairing of three-dimensional (3D) echocardiography with novel quantitative modeling techniques allows for a single modality description of the entire root complex. We sought to determine 3D aortic valve and root geometry with this quantitative approach.

METHODS

Transesophageal real-time 3D echocardiography was performed in five patients with tricuspid aortic valves (TAV) and in five patients with BAV. No patient had evidence of valvular dysfunction or aortic root pathology. A customized image analysis protocol was used to assess 3D aortic annular, valvular, and root geometry.

RESULTS

Annular, sinus and sinotubular junction diameters and areas were similar in both groups. Coaptation length and area were higher in the TAV group (7.25 ±  0.98 mm and 298 ± 118 mm² , respectively) compared to the BAV group (5.67 ± 1.33 mm and 177 ± 43 mm² ; P = .07 and P = .01). Cusp surface area to annular area, coaptation height, and the sub- and supravalvular tenting indices did not differ significantly between groups.

CONCLUSIONS

Single modality 3D echocardiography-based modeling allows for a quantitative description of the aortic valve and root geometry. This technique together with novel indices will improve our understanding of normal and pathologic geometry in the BAV population and may help to identify geometric predictors of adverse remodeling and guide tailored surgical therapy.

Predictors of Aortic Valve Repair Failure

Aortic valve repair is the preferred approach for the treatment of severe aortic insufficiency (AI), as it allows patients to keep their native aortic valve, thus substantially reducing the risk of prosthesis-related complications. Several studies have documented excellent long-term outcomes of aortic valve repair. The major complication of this operation is AI recurrence, with ensuingneed for reoperation. The surgical experience accumulated over the last two decades has allowed for better understanding of the mechanisms of recurrent AI after aortic valve repair. Herein, we review the current state of knowledge on predictors of aortic valve repair failure. These include unaddressed annular dilation, residual cusp prolapse or retraction, commissural orientation, and use of patch material. This enhanced understanding has led to the development of increasingly refined techniques and improved patient outcomes. Continued follow-up and detailed data collection at the time of surgery, together with three-dimensional echo imaging, will allow further improvements in aortic valve repair.

Geometry of cusp and root determines aortic valve function

The aortic valve is the functional unit of cusp and root. Various geometrical and functional analyses for the aortic valve unit have been executed to understand normal valve configuration and improve aortic valve repair. Different concepts and procedures have then been proposed for reparative approach, and aortic valve repair is still not standardized like mitral valve repair. It has become apparent, however, that interpretation of the geometry of the aortic cusp and root and its appropriate application to operative strategy lead to creating a functioning aortic valve. Herein, the aortic valve geometry and its clinical implications are reviewed to provide information for the selection of appropriate operative strategies.

Aortic root changes before and after surgery for chronic aortic dilatation: A 3D echocardiographic study

BACKGROUND

Quantitative 3D assessment of the aortic root may improve planning and success of aortic valve (AV)-sparing operations.

AIMS

To use 3D transesophageal echocardiography (TEE) to assess the effect of chronic aortic dilatation on aortic root shape and aortic regurgitation (AR) severity and to examine the effects of AV-sparing operations.

METHODS AND RESULTS

To determine the changes with chronic aortic dilatation, we studied 48 patients, 23 with aortic dilatation (Group 1 ≤ mild AR, n = 13; Group 2 ≥ moderate AR, n = 10) and 25 Controls. To determine the changes in AV-sparing operations, a subgroup of 15 patients were examined pre- and post surgery. 3D-TEE images were analyzed using multiplanar reconstruction (QLAB, Philips, Philips Medical Systems, Andover, MA, USA) to obtain aortic root areas, diameters, and lengths. We also calculated a novel parameter called total coaptation surface area (TCoapSA), which sums the contact surface area of all the AV cusps. Compared to Controls, Groups 1 and 2 had significantly larger aortic root areas, inter-commissural distances, and cusp heights. Compared to Group 1 and Controls, Group 2 had significantly smaller TCoapSA when adjusted for aortic annular area (P = 0.001) with shorter coaptation height (P < 0.001). In patients undergoing AV-sparing surgery, TCoapSA was significantly larger post surgery (P = 0.001) with greater coaptation height (P < 0.001) and smaller inter-commissural distances (P < 0.001).

CONCLUSIONS

The aortic valve is a dynamic structure that remodels in response to aortic dilatation. Successful valve-sparing surgery corrects these changes. Quantitative modeling of the aortic valve and root could potentially improve the repair to the individual patients and modify outcomes.

Aortic valve repair for aortic regurgitation and preoperative echocardiographic assessment

Aortic valvuloplasty (AVP) has been performed less frequently than mitral valvuloplasty. The survival benefit of AVP over replacement has been demonstrated. Therefore, standardization of AVP is crucial for its widespread adoption. The hemodynamic advantage of AVP of preserving the native aortic valve may be one reason for the survival benefit. Recent guidelines still recommend AVP in selected cases compared with the less restricted recommendation for mitral valvuloplasty, although recent studies have proposed earlier indication for surgical intervention. Indication for aortic root replacement is also still conservative, especially in Japan. However, more liberal root replacement should be recommended for better repair when AVP is indicated. Theoretically, all aortic regurgitation lesions can be repaired with acceptable durability. However, restricted cusp should be extended by a pericardial patch, which itself has emerged as a risk of recurrence. Therefore, indications for aortic regurgitation for type III lesions should be determined carefully. Special consideration is crucial for bicuspid aortic valve repair; prevention of postoperative stenosis is especially important. Arrangement of the commissure position is the most important consideration for this purpose, although it remains controversial. Therefore, detailed diagnosis is important in planning AVP, and echocardiography plays a key role in this process.

Aortic valve sparing root surgery for Marfan syndrome

Aortic valve sparing root surgery (AVSRS) is a safe and durable alternative for patients with dilated roots or pure aortic regurgitation (AR), which avoids the risks of anticoagulation or valvular degeneration with prosthetic valves. Notwithstanding the theoretical challenges of greater tissue fragility in Marfan syndrome (MFS), AVSRS has been demonstrated to have equal outcomes in this condition as it does in those without MFS. The benefits of retaining the native aortic valve in this generally younger age group extend beyond those of avoiding the inconvenience and complications of prolonged exposure to anticoagulants and include ease of management for future aortic, cardiac and non-cardiac procedures which are the norm for these patients. The essential principles of AVSRS in MFS do not differ from those for the rest of the population. Successful repair and durable valve function depend on a sound understanding of the close interaction between the structure and function of this exquisitely designed piece of engineering. We are fortunate to have numerous tools in our surgical armamentarium to preserve these valves. It is the purpose of this paper to demystify the complex structure-function interactions of the aortic valve, thereby gaining an intuition for AVSRS. We will also elaborate on specific technical details of established techniques that we have found successful in preserving the normal function of these valves in the long term.

Sparing aortic valve techniques

Prosthetic valve implantation is the most widely used therapeutic option for aortic regurgitation (AR), but complications associated with prosthetic valves, with an incidence of 3-5% patient/year, and the need for anticoagulation in mechanical valves, force us to consider aortic valve repair as an alternative to the prosthetic implant, especially in young people with many potential years of life for these complications. Aortic valve repair techniques are not excessively complicated, but there is no standardization, so they are not reproducible in all medical centers. There are multiple repair procedures, but to study them we can divide, arbitrarily, into two large groups, techniques for treatment of aortic root dilatation (reimplantation and remodeling); and repair techniques without treatment of the aortic root, that act on annulus and on aortic leaflets. The two sets of techniques are often used together, but it is easier to understand them if this arbitrary division is made. Our goal is to publish our experience and knowledge of repair techniques to facilitate their learning by other professionals. In this article, we will focus on the procedures on the aortic annulus and leaflets, because they can be applied in patients without aortic root dilatation, but they are also complementary to the reimplantation and remodeling techniques. We will present the procedures describing them individually, with an explanation in text accompanied by three videos in which the application of each technique is visualized in several cases. The standardization of sparing aortic valve techniques is difficult, because each patient requires its individualized application, yet we have tried to illustrate reproducible procedures so that professionals have more tools to deal with aortic valve-preserving surgery.

Cusp repair during aortic valve-sparing operation: technical aspects and impact on results

AIMS

Aortic valve-sparing operations are nowadays considered safe and reliable procedures in terms of mid-term and long-term results. Although surgical techniques regarding the modality of grafts' implantation have been properly addressed, the modality of cusp repair, when needed, is still open to debate. We sought to review the literature to try to shed light on when the cusp repair is required and how it should be performed.

METHODS

We searched the PubMed database using the keywords aortic valve-sparing operation, aortic valve-sparing reimplantation, valve-sparing aortic root replacement, aortic valve repair, and aortic cusp repair. Only studies that included and described in detail the technique of cusp repairs in adjunct to aortic valve-sparing operation were considered.

RESULTS

Bicuspid aortic valve more often requires correction when compared with tricuspid valve. The range of the techniques varies from the 'simple' free margin plication to the more complex triangular resection with patch repair. Results in the literature seem to be encouraging, showing that, in most of the cases, cusp repair does not affect valve competence in the mid-term and long-term.

CONCLUSION

Correction of the cusp is a delicate balance between undercorrection that could lead to residual prolapse and overcorrection that could lead to cusp restriction. Although complex repair of the aortic valve in addition to root replacement provided satisfactory results, it should be reserved for experienced centers with a large volume of patients.

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.

A Simple Device for Morphofunctional Evaluation During Aortic Valve-Sparing Surgery

Valve-sparing operations for the treatment of aortic root disease with a structurally normal aortic valve are increasingly performed as they avoid prosthesis-related complications. Short- and long-term results are critically dependent on perfect intraoperative restoration of valve anatomy and function. Residual aortic regurgitation is the main cause of early failure, and it is the most common motive for reoperation. However, intraoperative morphofunctional valve assessment requires expertise, and only transesophageal echocardiography can provide reliable information. We describe a simple, economic, reproducible hydrostatic test to intraoperatively evaluate valve competency under direct visualization.

Intraoperative Echocardiography for Congenital Aortic Valve Repair: Predictors of Early Reoperation

BACKGROUND

We sought to identify transesophageal echocardiography (TEE) predictors of early reoperation for recurrent aortic regurgitation (AR) after cardiopulmonary bypass (CPB) in patients undergoing repair for congenital aortic valve disease.

METHODS

We analyzed post-CPB TEEs in patients with congenital aortic valve disease undergoing repair for predominant AR. Case patients underwent reoperation for recurrent AR within 2 years, whereas control patients were free from reoperation for more than 3 years.

RESULTS

Case patients (n = 22; median time to reoperation 0.3 years) and control patients (n = 22; median freedom from reoperation ≥4.4 years) were similar for demographic characteristics, aortic dimensions, and preoperative AR grade. Among post-CPB TEE variables, univariate logistic regression analysis identified shorter coaptation height (odds ratio [OR] for 1-mm increase 0.72, 95% confidence interval [CI]: 0.54 to 0.95; p = 0.02), decreased ratio of coaptation height to annulus diameter (OR for a 5% decrease 1.37, 95% CI: 1.06 to 1.77; p = 0.02), and increased percentage difference (%diff) between longest and shortest coaptation lengths in a short-axis view (OR for 10% increase 1.84, 95% CI: 1.15 to 2.92; p = 0.01) as risk factors for early reoperation for recurrent AR. Multivariable analysis identified %diff in short-axis coaptation lengths as the strongest post-CPB TEE predictor (area under receiver operator curve = 0.743). The sensitivity and specificity of a %diff of 50% were 0.45 and 0.91, whereas a %diff of 30% had a sensitivity of 0.75 and specificity of 0.67.

CONCLUSIONS

Coaptation asymmetry, measured as increased %diff in short-axis coaptation lengths on post-CPB TEE, is associated with early reoperation for recurrent AR after congenital valve repair.

Minimally invasive valve sparing aortic root replacement (David procedure) is safe

OBJECTIVE

Even though minimally invasive cardiac surgery may reduce morbidity, this approach is not routinely performed for aortic root replacements. The purpose of this pilot study was to assess the safety and feasibility of valve sparing aortic root replacement via an upper mini-sternotomy up to the 3(rd) intercostal space.

METHODS

Between April 2011 and March 2014, 26 patients (22 males, age 47.6±13 years) underwent elective minimally invasive aortic valve sparing root replacement (David procedure, group A). Twelve patients underwent additional leaflet repair. Concomitant procedures were: four proximal aortic arch replacements and one coronary artery bypass grafting (CABG) to the proximal right coronary artery (RCA). During the same time period, 14 patients (ten males, age 64.2±9.5 years) underwent elective David procedure via median full sternotomy (group B). Concomitant procedures included six proximal aortic arch replacements. Although the patient cohorts were small, the results of these two groups were compared.

RESULTS

In group A, there were no intra-operative conversions to full sternotomy. The aortic cross-clamp and cardiopulmonary bypass (CPB) times were 115.6±30.3 and 175.8±41.9 min, respectively. One patient was re-opened (via same access) due to post-operative bleeding. The post-operative ventilation time and hospital stay were 0.5±0.3 and 10.4±6.8 days, respectively. There was no 30-day mortality. The patient questionnaire showed that the convalescence time was approximately two weeks. In group B: the cross-clamp and CPB times were 114.1±19.9 and 163.0±24.5 min, respectively. One patient was re-opened (7.1%) due to post-operative bleeding. The post-operative ventilation time and hospital stay were 0.6±0.7 and 14.2±16.7 days, respectively. There was no 30-day mortality.

CONCLUSIONS

Minimally invasive valve sparing aortic root replacement can be safely performed in selected patients. The results are comparable to those operated via a full sternotomy. The key to success is a 'step by step' technique of moving from minimally invasive aortic valve replacements (AVR) to more demanding aortic root replacements. Meticulous hemostasis & attention to surgical details is of utmost importance to prevent perioperative complications.

Aortic valve repair update

The key for successful valve repair is full understanding of the regurgitant mechanism and sufficient evaluation of the valve. Currently, multidetector computed tomography has been introduced for evaluation. The aortic valve can be analyzed in details preoperatively. The main causes of aortic regurgitation (AR) in the adult population are degenerative leaflet change and annulus dilatation. Restoration to normal structure can be accomplished mainly by plication. Central leaflet plication near the Arantius nodule is a simple technique for redundant tissue. For leaflet deficiency, pericardial patch plasty may be an option. No universal technique exists for plication of the aortic annulus. The valve-sparing aortic root replacement firmly stabilizes the ventriculo-aortic junction (VAJ) and assures repair durability even in patients with mild to moderate root dilatation. Subcommissural annuloplasty (Cabrol stitch) does not seem sufficient for the prevention of VAJ dilatation. Circumferential annuloplasties may have a greater potential. However, convenient device for annular plication is still in development. The bicuspid aortic valve is a congenital heart valve lesion. A basic technique is free margin plication of the fused leaflet. Aortic root dilatation may contribute to AR severity. Valve-sparing aortic root replacement may improve repair durability. Considering the great advances in valve repair, young patients with AR should be informed that valve repair is a promising option for surgical treatment.

Current readings: Aortic valve-sparing operations

It has been more than 2 decades since aortic valve-sparing operations were introduced to preserve the aortic valve in patients with aortic root aneurysm. Remodeling of the aortic root is physiologically superior to reimplantation of the aortic valve, mostly because it preserves the aortic annulus movement during the cardiac cycle. However, several comparative studies have shown that reimplantation of the aortic valve has provided more stable aortic valve function than remodeling of the aortic root. This difference in outcomes is largely because of patients׳ selection. Remodeling of the aortic root has been associated with high failure rates in patients with aneurysms associated with genetic syndromes and bicuspid aortic valves with dilated aortic annulus, but it has provided excellent long-term results in older patients with aortic root aneurysms secondary to ascending aortic aneurysms and normal aortic annulus. Thus, both techniques are useful in preserving the aortic valve. With either technique, restoration of normal aortic annulus and cusp geometry is the single most important technical aspect of these operations. In addition to having a competent valve with no or trivial aortic insufficiency at the end of the operation, there must be no cusp prolapse and the coaptation level of the cusps has to be well above the level of the nadir of the aortic annulus.

The role of transesophageal echocardiography in aortic valve preserving procedures

In selected cases of aortic regurgitation, aortic valve (AV) repair and AV sparing root reconstruction viable alternatives to aortic valve replacement. Repair and preservation of the native valve avoids the use of long-term anticoagulation, lowers the incidence of subsequent thromboembolic events and reduces the risk of endocarditis. Additionally repair has a low operative mortality with reasonable mid-term durability. The success and longer term durability of AVPP has improved with surgical experience. An understanding of the mechanism of the AR is integral to determining feasibility and success of an AVPP. Assessment of AV morphology, anatomy of the functional aortic annulus (FAA) and the aortic root with transesophageal echocardiography (TEE) improves the understanding of the mechanisms of AR. Pre- and intra-operative TEE plays a pivotal role in guiding case selection, surgical planning, and in evaluating procedural success. Post-operative transthoracic echocardiography is useful to determine long-term success and monitor for recurrence of AR.

Contemporary midterm echocardiographic outcomes of Bentall procedure and aortic valve sparing root replacement

BACKGROUND

Valve sparing root replacement (VSRR) and aortic valve repair (AVr) is an attractive treatment option compared with composite valve and root replacement (Bentall procedure) for patients with aortic root dilatation with or without aortic valve disease. While aortic valve preservation reduces the risk of valve-related complications, little is known about echocardiographic differences at follow-up between these 2 strategies.

METHODS

Consecutive nonemergent patients undergoing VSRR and AVr (n=68) were compared with contemporary historical controls undergoing the Bentall procedure for aortic root pathology with or without mixed aortic valve disease (insufficiency or stenosis) (n=96). The VSRR was performed preferentially using the reimplantation technique. Bentall procedure utilized a mechanical valve in 65% of patients, a biologic prosthesis in 22%, and a homograft in 13%. Clinical and echocardiographic data were obtained at baseline and at follow-up (median=30 months).

RESULTS

The 2 cohorts were similar with respect to all preoperative characteristics with the exception of disease etiology. The Bentall group had a higher proportion of degenerative valve and root disease (47.8% vs 27.9%) and a lower proportion of bicuspid aortic valve disease (22.8% vs 51.5%) as compared with the VSRR group (p=0.007). Postoperative echocardiographic outcomes were comparable between groups with the exception of higher peak (23.37±11.80 vs 18.0±12.04; p=0.02) and mean (13.07±7.53 vs 9.56±6.49; p=0.01) transvalvular aortic gradients in the Bentall group. Persistence of left ventricular dysfunction (8.4% vs 6.1%; p=0.61), presence of greater than moderate aortic valve (AV) insufficiency (3% vs 4.6%; p=0.32), and left ventricular mass (213.24±72.36 vs 207.38±63.07, p=0.61) were comparable between the Bentall and VSRR group, respectively. Finally, survival (p=0.21) and freedom from valve-related events (p=0.74) were similar between groups.

CONCLUSIONS

Valve sparing root replacement with AV repair provides similar mid-term echocardiographic and clinical outcomes compared with the Bentall.

Valve cuspidity: a risk factor for aortic valve repair?

BACKGROUND

The aim of this study was to analyze short- and mid-term results after aortic valve (AV) repair with particular regard to the impact of valve cuspidity (bicuspid versus tricuspid aortic valve).

METHODS

One hundred patients with aortic regurgitation (AR) undergoing aortic valve repair between November 2007 and October 2012 were included in the study. Sixty patients had bicuspid AV (BAV group; 11 females) and 40 patients had tricuspid AV (TAV group; 13 females). AR > grade 2 was present in 47 (78%) patients in the BAV and in 35 (88%) patients in the TAV group. Follow-up was complete in 100% and median was 25 months.

RESULTS

Isolated aortic valve repair was performed in 27 (45%) of BAV patients and in six (15%) of TAV patients. Replacement of the ascending aorta and/or aortic root was performed in 33 (55%) of BAV patients and in 34 (86%) of TAV patients. There was no death within 30 days postoperatively, while two patients died (TAV group) during the follow-up period. There was no statistical difference between BAV and TAV groups with regard to the survival (100 ± 0% vs. 95 ± 4%, p = 0.102), the three-year freedom from AV-related reoperation (90 ± 5% vs. 89 ± 6%, p = 0.456), and the three-year freedom from AR grade > 2 (86 ± 6% vs. 82 ± 7%, p = 0.866), respectively.

CONCLUSIONS

This study demonstrates no difference in mid-term results after regurgitant bicuspid and tricuspid aortic valve repair, suggesting that bicuspid valve may not be a risk factor for aortic valve repair.

Differences in aortic cusp coaptation between the reimplantation and the remodeling techniques of aortic valve-sparing surgery: an in vitro porcine model study

OBJECTIVES

We sought to evaluate the effects of the reimplantation type versus the remodeling type of aortic valve-sparing technique on the geometry of the same aortic root.

METHODS

Fifteen fresh isolated porcine hearts with normal aortic valves and a standard aortoventricular junction size of 23 mm were processed. An aortic valve-sparing replacement was performed by reimplanting the native aortic root inside a 28-mm Valsalva graft (Vascutek Ltd, Renfrewshire, UK). Hearts were subsequently implanted with instruments in a test circuit, and the aortic roots were pressurized at a fixed pressure of 100 mm Hg. Diameters of the aortoventricular junction, of the sinuses, and of the sinotubular junction, as well as effective height and coaptation height of aortic valve leaflets, were measured by echography. Transition from the reimplantation to the remodeling configuration was then achieved by longitudinally cutting the skirt of the graft from the annulus to the top of each commissure. The same measurements were then repeated.

RESULTS

After transition from the reimplantation to the remodeling configuration, significant increases in the sizes of the aortoventricular junction and of the sinuses were observed. Effective height and coaptation height significantly decreased, and the rounded cross-sectional profile of the aortic valve leaflets flattened.

CONCLUSIONS

In the same aortic root, transition from the reimplantation to the remodeling configuration of aortic valve-sparing surgery results in a significant increase in aortic root sizes and in a significant reduction of effective height and coaptation height, suggesting a less satisfactory result.