The Ross operation - a feasible and safe option in the setting of a bicuspid aortic valve?

Unicuspid Aortic Valve in Patients Undergoing the Ross Procedure

BACKGROUND

The prevalence and outcomes of the unicuspid aortic valve (UAV) in patients undergoing the Ross procedure have been strongly underreported in the current literature. We sought to evaluate this in comparison with bicuspid (BAV) and tricuspid valve (TAV) in our Ross cohort.

METHODS

This was a retrospective observational study of patients undergoing the Ross procedure at 2 dedicated centers between 2009 and 2020. Primary end points were the risks of midterm autograft reoperation and the onset of at least moderate aortic regurgitation during follow-up. The secondary end point was to compare the perioperative outcomes between the groups.

RESULTS

Included in the analysis were 286 patients, of those 39% with UAV, 52% with BAV, and 9% with TAV. UAV patients were operated on at the youngest age (P < .001) and more often for a combined hemodynamic aortic valve pathology (P = .02). They had the largest aortic root dimensions: annulus (P = .01), Valsalva sinuses (P = .11), sinotubular junction (P = .001), and ascending aorta (P < .0001). The risks of reoperation (P = .86) and the onset of aortic regurgitation (P = .75) were comparable among the groups over the follow-up of 4.1 years. There was no difference in perioperative outcomes.

CONCLUSIONS

UAV is a separate unit characterized by a distinct hemodynamic pathology and generated aortopathy. It is not associated with a higher risk of reoperation or new onset of aortic regurgitation after the Ross procedure in the midterm postoperatively. At the current state, UAV remains acceptable for the Ross procedure.

Long-term outcomes with the pulmonary autograft inclusion technique in adults with bicuspid aortic valves undergoing the Ross procedure

OBJECTIVE

To compare outcomes with wrapped (pulmonary autograft inclusion) versus unwrapped techniques in adults with bicuspid aortic valves undergoing the Ross procedure.

METHODS

Between 1992 and 2019, 129 adults with bicuspid aortic valves (aged ≥18 years) underwent the Ross procedure by a single surgeon. Patients were divided into those without autograft inclusion (unwrapped, n = 71) and those with autograft inclusion (wrapped, n = 58). Median follow-up was 10.3 years (interquartile range, 3.0-16.8 years). Need for autograft reintervention was analyzed using competing risks.

RESULTS

Pre- and intraoperative characteristics as well as 30-day morbidity or mortality did not differ between cohorts. Survival at 1, 5, and 10 years, respectively, was 97.2%, 97.2%, and 95.6% in the unwrapped cohort and 100%, 100%, and 100% in the wrapped cohort (P = .15). Autograft valve failure occurred in 25 (35.2%) of the unwrapped and 3 (5.2%) of the wrapped patients. Competing risks analysis demonstrated the wrapped cohort to have a lower need for autograft reintervention (subhazard ratio, 0.28, 95% confidence interval, 0.08-0.91; P = .035). The cumulative incidence of autograft reintervention (death as a competing outcome) at 1, 5, and 10 years, respectively, was 10.2%, 14.9%, and 26.8% in the unwrapped cohort and 4.0%, 4.0%, and 4.0% in the wrapped cohort.

CONCLUSIONS

In adults with bicuspid aortic valves, the Ross procedure with pulmonary autograft inclusion stabilizes the aortic root preventing dilatation and reduces the need for reoperation. The autograft inclusion technique allows the Ross procedure to be performed in this population with excellent long-term outcomes.

Bicuspid Aortic Stenosis with and without Aortopathy: Considerations for Surgical Aortic Valve Replacement versus Transcatheter Aortic Valve Replacement

The treatment of aortic stenosis has evolved in recent years with the introduction of transcatheter aortic valve replacement (TAVR) as a complementary strategy to surgical aortic valve replacement (SAVR). The majority of clinical trials to date have included only tricuspid aortic stenosis and excluded bicuspid aortic valves (BAVs). BAVs are associated with unique challenges related to their anatomy, clinical presentation, and association with aortopathy. BAV has a spectrum of phenotypes and the classification is still evolving. There have been no definitive clinical guidelines on triaging BAV patients towards TAVR or SAVR. Given that TAVR is moving from high-risk to low-risk patients and becoming more widely used in the treatment of BAV, there are many factors that must be considered. The aim of this article is to review the literature and present considerations for heart teams to discuss in order to offer patients the best lifetime management strategy for BAV stenosis.

Bicuspid Aortic Valves: an Up-to-Date Review on Genetics, Natural History, and Management

PURPOSE OF REVIEW

Bicuspid aortic valve (BAV) is the most common congenital cardiac abnormality. It has a wide spectrum of clinical manifestations including aortic regurgitation (AR), aortic stenosis, and an associated aortopathy with a small but increased risk of aortic dissection. This review describes current knowledge of BAV, from anatomy and genetics to a discussion of multifaceted strategies utilized in the management of this unique patient population. This review will also highlight critical knowledge gaps in areas of basic and clinical research to enhance further understanding of this clinical entity.

RECENT FINDINGS

The current knowledge regarding pathophysiologic mechanisms, screening, and surveillance guidelines for BAV and the associated aortopathy is discussed. We also discuss current management techniques for aortic valve repair versus replacement, indications for aortic surgery (root or ascending aorta), and the emergence of the Ross procedure as a viable management option not only in children, but also in adolescents and adults. The varied clinical phenotype of the BAV, resulting in its specific complex hemodynamic interactions, renders it an entity which is separate and distinct from the tricuspid aortic valve pathologies. While various aortic histopathologic and protein alterations in BAV patients have been described, it remains unclear if these changes are causal or the result of hemodynamic alterations imposed by sheer stress on the intrinsically dysfunctional BAV. Medical management for patients with BAV with AS, AI, or dilated aortic roots/ascending aortas remains challenging and needs further investigation. More than 50% of patients with BAV will undergo AVR during their lifetime, and more than 25% of patients with BAV undergo aortic surgery performed for dilation of the aortic root or ascending aorta, often concurrently with AVR. The search for the ultimate genetic or epigenetic cause of the different bicuspid phenotypes will ultimately be facilitated by the next-generation sequencing tools that allow for study of large populations at low cost. Improvements in diagnostic and stratification criteria to accurately risk assess BAV patients are critical to this process.

The Ross procedure is an excellent operation in non-repairable aortic regurgitation: insights and techniques

The Ross procedure is the best operation to treat aortic stenosis (AS) in young and middle-aged adults. However, its role in non-repairable aortic regurgitation (AR) remains debated since many historical series have reported an increased risk of pulmonary autograft dilatation and subsequent need for reintervention in these patients. Some have attributed these findings to an unrecognized and poorly characterized inherited genetic defect that prevents adaptive remodelling of the pulmonary autograft. Herein, we review the contemporary evidence surrounding the use of the Ross procedure in young adults with AR and put forth the argument that with proper technical refinements, the Ross procedure may still be the best operation to treat these patients. We believe that by tailoring the operation to the patient's anatomy and ensuring strict postoperative blood pressure control, one can achieve excellent results with the Ross procedure, including in this challenging patient population.

The Choice of Pulmonary Autograft in Aortic Valve Surgery: A State-of-the-Art Primer

The Ross procedure has long been seen as an optimal operation for a select few. The detractors of it highlight the issue of an additional harvesting of the pulmonary artery, subjecting the native PA to systemic pressures and the need for reintervention as reasons to avoid it. However, the PA is a living tissue and capable of adapting and remodeling to growth. We therefore review the current evidence available to discuss the indications, contraindications, harvesting techniques, and modifications in a state-of-the-art narrative review of the PA as an aortic conduit. Due to the lack of substantial well-designed randomized controlled trials (RCTs), we also highlight the areas of need to reiterate the importance of the Ross procedure as part of the surgical armamentarium.

Outcomes and Quality of Life After Ross Reintervention: Would You Make the Same Choice Again?

BACKGROUND

The Ross procedure was introduced as a long-term if not definitive solution for aortic pathology. However, the rate of reoperation is not negligible.

METHODS

This single-center prospective study assessed the general outcome of Ross reoperation and patients' perceived quality of life compared with 2 control groups (Ross non-reoperation and mechanical aortic valve replacement). Patient's preference regarding the choice between mechanical aortic valve and Ross procedure was investigated in a subgroup that could theoretically have been directed to either of the 2 procedures.

RESULTS

Between 2005 and 2017, 64 consecutive patients underwent reoperation after Ross. Median age was 31 years. Median freedom from reoperation after the Ross procedure was 136 months. An autograft reoperation was required in 49, and 25 had homograft failure. No in-hospital death was recorded. Mean follow-up was 77 months (range, 6-164 months). Quality of life was assessed with the 36-Item Short Form Health Survey questionnaire. The Ross reoperation group showed a lower score involving psychological concerns compared with the other groups. In the reoperated-on patients group, 52 had adequate aortic annulus dimensions to receive a prosthetic valve instead of a Ross procedure. When asked whether they would make the same choice, only 31% confirmed the preference.

CONCLUSIONS

Reoperations after Ross procedure have low mortality and morbidity. Long-term follow-up showed a high quality of life, even after reoperations. However, owing to psychological concerns after the redo operation, when choosing a Ross procedure, it is our duty to thoroughly explain to patients that a high level of disillusion is predictable in case of reoperations.

Does the pattern of bicuspid aortic valve leaflet fusion determine the success of the Ross procedure?

BACKGROUND

In addition to being associated with aortopathy, a bicuspid aortic valve (BAV) has been posed to be a risk factor for the dilation of the pulmonary autograft in the aortic position. The aim of this study is to assess the association between the subtype of native aortic valve leaflet fusion (right and noncoronary leaflets [R/N] vs right and left leaflets [R/L]) and autograft dilation and valve dysfunction after the Ross procedure.

METHODS

We performed a retrospective review of 43 patients with BAV who underwent a Ross procedure in our center from 1993 to 2013. Serial transthoracic echocardiography was used to measure changes in autograft and ascending aortic diameter over time. The aortic diameter was measured at four levels, and Z values were computed. Aortic dilation was defined as a Z value greater than 3.

RESULTS

The mean age at the time of the Ross procedure was 13.5 ± 9.2 years. R/L was the most prevalent native aortic valve subtype (R/L, n = 26, 61% vs R/N, n = 17, 39%). PreRoss procedure, aortic dilation was more frequent in patients with R/N fusion (P = .02), whereas the initial aortic valve gradient and grade of aortic insufficiency (AI) did not differ between the subgroups. At follow-up, (mean = 9.6 ± 4.3 years) dilation of the autograft and ascending aorta was seen more often in patients with R/N leaflet fusion (P = .03). Conversely, the prevalence of more than moderate AI was significantly higher in patients with R/L leaflet fusion (P = .03). There was no significant difference between groups among numbers of late reintervention on the aortic valve or root (P = .75); however the type of intervention varied by morphologic subtype. Patients with R/L fusion underwent more aortic valve replacements (AVRs) while patients with R/N fusion underwent more valve-sparing aortic root replacements.

CONCLUSIONS

After Ross procedure, both groups of patients were likely to have a combination of dilation of the aortic root and the tubular portion of the ascending aorta at follow-up. Patients with R/L fusion were more likely to have a prevalence of root dilation, while patients with R/N fusion were more likely to have tubular ascending aorta dilation. The R/L phenotype is associated with a slightly more rapid dilation at follow-up and is more likely to have postoperative autograft insufficiency. This information may serve to guide patient and procedure selection for AVR.

The Ross procedure in adults presenting with bicuspid aortic valve and pure aortic regurgitation: 85% freedom from reoperation at 20 years

OBJECTIVES

The Ross procedure has demonstrated excellent results when performed in patients with aortic stenosis or mixed aortic valve disease [aortic stenosis and aortic regurgitation (AR)]. However, due to its reported risk of late reoperation, it is not recommended under current guidelines for patients presenting with bicuspid aortic valve and pure AR. We have analysed our own results in light of this recommendation.

METHODS

Between 1993 and 2016, 129 consecutive patients with a mean age of 34.7 ± 10.6 years (range 16-64 years) presented with bicuspid aortic valve and pure AR and underwent the Ross procedure. Patients were reviewed annually and had 2nd yearly transthoracic echocardiograms during follow-up. The unit had a liberal reoperation policy where reoperation was performed if patients developed recurrent moderate or greater AR during follow-up.

RESULTS

There was 1 inpatient death, and 3 late deaths over a mean follow-up duration of 9.6 ± 6.8 years. Late survival at 10 and 20 years post-surgery were 99% [95% confidence interval (CI) 94-100] and 95% (95% CI 85-99), respectively. Eleven patients underwent redo aortic valve replacement (AVR) and 4 patients had redo pulmonary valve replacement. Freedom from reoperation for AVR and more-than-mild AR at 10 and 20 years post-surgery were 89% (95% CI 81-94) and 85% (95% CI 74-92), respectively. Having longer aortic cross-clamp (hazard ratio 1.03, 95% CI 1.00-1.06; P = 0.05) and cardiopulmonary bypass times (hazard ratio 1.02, 95% CI 1.00-1.05; P = 0.05), and having a larger preoperative sinotubular junction diameter (hazard ratio 1.15, 95% CI 1.03-1.30; P = 0.02) were significant predictors of having redo AVR or significant AR at follow-up.

CONCLUSIONS

With a 20-year freedom from redo AVR and greater-than-mild residual AR of 85%, the utilization of the Ross procedure in bicuspid aortic valve patients with pure AR should be considered.

Bicuspid aortic valve disease: systematic review and meta-analysis of surgical aortic valve repair

Aortic valve repair is still emerging, and its role in the treatment of bicuspid aortic valve disease (BAVD) is not yet fully understood. Our objective is to synthesise available evidence on outcomes after surgical aortic valve repair in patients with BAVD. We conducted a systematic review of clinical studies using prespecified methods for searching, identifying and selecting eligible studies in 4 databases, and synthesising results (PROSPERO 2014:CRD42014014415). 2 researchers independently reviewed full-text articles and extracted data. The results of included studies were quantitatively synthesised in frequentist meta-analyses. We included 11 aortic valve repair studies or study arms with a total of 2010 participants. Pooled estimates for the proportion of patients surviving at 30 days, 1 year, 5 years and 10 years were 0.995 (95% CI 0.991 to 0.995), 0.994 (0.989 to 0.999), 0.945 (0.898 to 0.993) and 0.912 (0.845 to 0.979), respectively. The pooled proportion of late deaths from valve-related causes was 0.008 (0.000 to 0.019) at a mean follow-up of 3.5 years. Proportion of patients with valve-related reinterventions was 0.075 (0.037 to 0.113) at a mean follow-up of 3.9 years, and the linearised reintervention rate was 1.3 (0.7 to 1.9) per 100 patient-years. Outcome reporting was insufficient to pool the results for a number of predefined outcomes. In conclusion, existing evidence on aortic valve repair in BAVD is limited to mostly small case series, case-control and small retrospective cohort studies. Despite the low quality, available evidence suggests favourable survival outcomes after aortic valve repair in selected patients with BAVD. Valve-related reinterventions at follow-up are common in all patients undergoing repair surgery.

Root remodeling and aortic valve repair for unicuspid aortic valve

BACKGROUND

Unicuspid aortic valve (UAV) anatomy is occasionally encountered in adolescents or young adults and not infrequently associated with aneurysm of the ascending aorta and aortic root. To manage both defects without aortic valve replacement we propose a combination of remodeling of the aortic root combined with bicuspidization of the UAV.

METHODS

Between 1 December 2007 and November 2013, 25 patients (23 males; mean age, 38 ± 12 years; range, 21 to 65 years) with aortic regurgitation as a result of UAV and aortic root dilatation underwent remodeling of the aortic root and bicuspidization of the UAV. The dilated aortic root tissue was resected, leaving the wall adjacent to the normal commissure and at 180 degrees orientation and similar height for the new commissure. The graft was configured to create two symmetric tongues of graft and sutured to the remnants of the aortic root wall. The dysplastic right coronary cusp was resected, and autologous pericardial patches augmented the deficiency of cusp tissue between the left and noncoronary cusps. A suture annuloplasty was used in 20 cases. All patients were followed clinically and echocardiographically at 3, 6, and 12 months and at yearly intervals. Cumulative follow-up was 677 months (mean, 27 ± 18 months).

RESULTS

No early or late death occurred. Intraoperative echocardiography revealed minimal or no aortic regurgitation in all patients; at discharge, systolic mean gradient was 6 ± 3 mm Hg. There was no bleeding or thromboembolic event during the follow-up. One patient exhibited endocarditis and underwent reoperation. Two patients experienced relevant recurrent aortic regurgitation for limited suture dehiscence between the patch and the cusp and were reoperated on between 16 and 32 months postoperatively. One patient underwent biologic valve replacement, and two valves were re-repaired. At 5 years, freedom from reoperation and aortic valve replacement was 81% and 91%, respectively.

CONCLUSIONS

In the presence of UAV and aortic root dilatation, the concept of valve bicuspidization and root remodeling can be applied with satisfactory hemodynamic results. The hemodynamic function of an aortic valve preserved by this concept is good. If sufficient stability can be achieved, aortic valve replacement can be avoided in young patients with aortic regurgitation caused by UAV and root aneurysm.

Fate of the remaining neo-aortic root after autograft valve replacement with a stented prosthesis for the failing ross procedure

BACKGROUND

Aortic root replacement (ARR) is advocated for irreparable autograft failure after the Ross procedure to avoid late aneurysm formation. However, redo ARR is complex and associated with bleeding and coronary injury risks. We examine results of autograft valve replacement (AuVR) with stented prostheses (SP) without ARR with special focus on the fate of the remaining root and need for reintervention.

METHODS

Between 1994 and 2011, 50 of 510 Ross patients underwent AuVR with SP. Serial postoperative echocardiograms (n = 342) were analyzed and regression models adjusted for repeated measures were used to model longitudinal change of the remaining root and ascending aorta dimensions after AuVR.

RESULTS

Fifty patients, median age 21 years (range 11 to 50 years) underwent AuVR with SP: mechanical (n = 38) or tissue (n = 12). Thirty patients (60%) had concomitant procedures; most commonly mitral valve surgery (n = 20) or conduit change (n = 12). There were no operative deaths and 10-year survival was 95%. Freedom from prosthesis, root, and all-cause reoperations was 97%, 98%, and 90% at 10 years, respectively. Serial echocardiography data showed that there was little but, nevertheless, progressive increase of the remaining root (EST: +0.0190 [0.0041] cm/year, p < 0.001) and ascending aorta diameters (EST: +0.0191 [0.0037] cm/year, p < 0.001). While there was small steady non-statistically significant increase in mean prosthesis gradient (estimate [EST]: +0.16 [0.09] mm Hg/year, p = 0.08); ejection fraction remained stable with time (EST: -0.12 [0.14] %/year, p = 0.41).

CONCLUSIONS

Our results indicate that AuVR with SP without ARR for failing autografts is justified as it is associated with low mortality and reoperation risk. Preemptive complex ARR should be reserved for those with significant root dilatation at time of AuVR. Although root reinterventions are rare, patients should be followed for progressive root dilatation. Faster growth is seen in those who fail with regurgitation and dilated annulus.