Redo aortic root surgery post-Ross procedure

Background

Despite numerous advantages of the Ross procedure, it presents a risk of late autograft and right ventricular outflow tract conduit failure. This study aimed to analyze the outcomes of autograft dysfunction reoperations using autograft-sparing and root replacement techniques.

Methods

Between 2015 and 2023, 49 patients underwent redo root surgery in our institution. Autograft valve-sparing procedures (VSP) were performed in 20 cases and the Bentall procedure (BP) in 29 patients. The short and long-term clinical outcomes along with echocardiographic results of VSP and BP were investigated.

Results

Overall early mortality rate was 2.0% with no significant difference between the groups. Severe autograft valve insufficiency at the time of redo (OR 4.07, P = 0.03) and patient age (OR 1.07, P = 0.04) were associated with a valve replacement procedure instead of VSP. The median follow-up duration was 34 months. No late deaths occurred in either group. Freedom from VSP failure and aortic prosthesis dysfunction were 93.8% and 94.1% in the VSP and BP groups, respectively. No reoperations were necessary in either group.

Conclusion

Redo aortic root surgery can be safely performed in patients with autograft failure. Both root replacement and autograft valve-sparing procedures demonstrated acceptable results at mid-term follow-up. Early redo surgery pre-empting severe aortic insufficiency increases the likelihood of preservation of the dilated autograft valve.

Long-term Outcomes of the Ross Procedure for Young Patients with Aortic Valve Disease

To define current role of the Ross operation in young patients, the outcome in those followed longer than 20 years were assessed. Between 1994 and 2020, 81 consecutive patients, 70 of 11 male and/or female, mean age 27 years underwent Ross procedure, accruing 20 years of follow-up or longer. Sixty-four had bicuspid valve (79%) and 54 (67%) aortic insufficiency, while 15 (19%) had undergone prior operations. Surgery consisted in root replacement in 53 patients, cylinder inclusion in 20 and sub-coronary graft in 8. There were 7 late deaths in 80 hospital survivors (median follow-up 21 years, IQR 20-23), with 88% ± 5% survival at 25 years. Thirty-four patients required left, 6 left and/or right and 1 right heart valve reoperation, on average 13 years after Ross procedure. Reoperation was valve-sparing in 18 (45%) patients and valve and/or root replacement in 22. Ten (24%) reoperated patients required a second reoperation 18 years after Ross procedure. Freedom from autograft reoperation was 46% ± 6%, while from autograft valve replacement was 60% ± 7%, thanks to autograft valve-sparing. Freedom from isolated right valve reoperation was 98% ± 4%. No mortality was associated with any of the 51 reoperations. Root technique was associated with reoperation (P = 0.024). Age at follow-up was 50 years (IQR 36-60), with 70 (96%) patients in NYHA class I and 6 (55%) women carrying out pregnancies. Young patients undergoing the Ross procedure enjoy unprecedented survival well into the third decade of follow-up, even when faced with reoperation. At 25 years risk of autograft reoperation is consistent, while negligible for homograft. Technical improvements at operation and valve-sparing at reoperation may prolong autograft valve durability.

Biomechanics of Pulmonary Autograft as Living Tissue: A Systematic Review

Introduction: The choice of valve substitute for aortic valve surgery is tailored to the patient with specific indications and contraindications to consider. The use of an autologous pulmonary artery (PA) with a simultaneous homograft in the pulmonary position is called a Ross procedure. It permits somatic growth and the avoidance of lifelong anticoagulation. Concerns remain on the functionality of a pulmonary autograft in the aortic position when exposed to systemic pressure. Methods: A literature review was performed incorporating the following databases: Pub Med (1996 to present), Ovid Medline (1958 to present), and Ovid Embase (1982 to present), which was run on 1 January 2022 with the following targeted words: biomechanics of pulmonary autograft, biomechanics of Ross operation, aortic valve replacement and pulmonary autograph, aortic valve replacement and Ross procedure. To address the issues with heterogeneity, studies involving the pediatric cohort were also analyzed separately. The outcomes measured were early- and late-graft failure alongside mortality. Results: a total of 8468 patients were included based on 40 studies (7796 in pediatric cohort and young adult series and 672 in pediatric series). There was considerable experience accumulated by various institutions around the world. Late rates of biomechanical failure and mortality were low and comparable to the general population. The biomechanical properties of the PA were superior to other valve substitutes. Mathematical and finite element analysis studies have shown the potential stress-shielding effects of the PA root. Conclusion: The Ross procedure has excellent durability and longevity in clinical and biomechanical studies. The use of external reinforcements such as semi-resorbable scaffolds may further extend their longevity.

Supporting the Ross procedure: preserving root physiology while mitigating autograft dilatation

PURPOSE OF REVIEW

The purpose of this article is to describe the optimized approach to nonrepairable aortic valve disease in young adults with a Ross procedure, while preserving the dynamic physiology of the aortic root.

RECENT FINDINGS

As the techniques for supporting pulmonary autografts continue to be refined, and the applicability of the Ross procedure continues to expand, an assessment of the various techniques based on aortic root physiology is warranted. Semi-resorbable scaffolds show promise in ovine models for improving the Ross procedure. Recent long-term outcomes for the Dacron inclusion technique in comparison to more physiologic methods of support emphasize the importance of balancing the prevention of early dilatation with the preservation of root haemodynamics. As this review will synthesize, the dynamic physiology of the root may be preserved even in patients at a higher risk of autograft dilatation.

SUMMARY

The favourable long-term outcomes of the Ross procedure can be partly attributed to the ability of the autograft to restore dynamism to the neoaortic root. Patient-specific modifications that respect root physiology can tailor the Ross procedure to address each patient's risk factors for early dilatation and late failure. As such, the Ross procedure should be recognized as an increasingly favourable solution for a wide spectrum of nonpreservable aortic valve disease in young adults.

The effectiveness and safety of pulmonary autograft as living tissue in Ross procedure: a systematic review

BACKGROUND

Reports on effectiveness and safety after the implant of pulmonary autograft (PA) living tissue in Ross procedure, to treat both congenital and acquired disease of the aortic valve and left ventricular outflow tract (LVOT), show variable durability results. We undertake a quantitative systematic review of evidence on outcome after the Ross procedure with the aim to improve insight into outcome and potential determinants.

METHODS

A systematic search of reports published from October 1979 to January 2021 was conducted (PubMed, Ovid Medline, Ovid Embase and Cochrane library) reporting outcomes after the Ross procedure in patients with diseased aortic valve with or without LVOT. Inclusion criteria were observational studies reporting on mortality and/or morbidity after autograft aortic valve or root replacement, completeness of follow-up >90%, and study size n≥30. Forty articles meeting the inclusion criteria were allocated to two categories: pediatric patient series and young adult patient series. Results were tabulated for a clearer presentation.

RESULTS

A total of 342 studies were evaluated of which forty studies were included in the final analysis as per the eligibility criteria. A total of 8,468 patients were included (7,796 in pediatric cohort and young adult series and 672 in pediatric series). Late mortality rates were remarkably low alongside similar age-matched mortality with the general population in young adults. There were differences in implantation techniques as regard the variability in stress and the somatic growth that recorded conflicting outcomes regarding the miniroot vs the subcoronary approach.

DISCUSSION

The adaptability of lung autograft to allow for both stress variability and somatic growth make it an ideal conduit for Ross's operation. The use of the miniroot technique over subcoronary implantation for better adaptability to withstand varying degrees of stress is perhaps more applicable to different patient subgroups.

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.

Outcomes of reoperations after Ross procedure

Background

Potential for difficult reoperations has been a concern for patients undergoing a Ross procedure. Data regarding the outcomes of such reoperations is extremely limited. We examined our experience to define the current scope and risk of these operations.

Methods

Between 1996 and 2020, 83 patients who had a previous Ross procedure underwent 89 reoperative surgeries. There were 72 males and average age was 48 with a range of 18-76. Twenty-four patients had more than one prior reoperation, with five patients having more than one reoperation post Ross. Patients were stratified by primary reason for reoperation including autograft dysfunction, homograft dysfunction, or other cardiac surgical problems. Demographic, operative, and outcomes data were collected from clinical records and placed in a secure data base for analysis.

Results

A total of 176 procedures were done in the 89 operations. Autograft dysfunction affected 68 patients. Homograft dysfunction affected 27 patients. Both of these were seen in 17 patients. Other cardiac problems required 79 other procedures. There were two (2.2%) operative deaths, with perioperative morbidity affecting six patients (6.7%). Survival following reoperation after Ross was 82.3% and 77.5% (±2), at ten and fifteen years respectively.

Conclusions

Reoperations after a Ross procedure can be challenging but can be done with a high degree of safety and long-term benefit in experienced hands.

Long-term outcomes of the Ross procedure in adults

BACKGROUND

The optimal aortic valve replacement for young and middle-aged adults remains elusive. Although several high-volume international centers and surgeons have demonstrated excellent long-term results with the pulmonary autograft (Ross procedure) in adult patients, current guidelines from the United States do not favor this technique. We evaluated long-term clinical and echocardiographic outcomes of adult patients undergoing the Ross procedure at our center.

METHODS

A retrospective review of 225 consecutive adult patients undergoing the Ross procedure was completed. Kaplan-Meier analysis was performed to evaluate overall survival, which was then compared to an age- and sex-matched general population with the log-rank test. Accounting for death as a competing hazard, the cumulative incidence of reintervention and autograft or homograft dysfunction were estimated over the long-term.

RESULTS

Mean age was 42±11 years, and 62 (28%) patients were at least 50 years old. A bicuspid aortic valve was present in 179 (80%) patients. The most common indications for surgery were aortic insufficiency (n=94, 43%), aortic stenosis (n=81, 36%), and mixed etiology (n=46, 21%). In-hospital mortality was 0.9%. Overall survival (with 95% confidence intervals) at 1-, 10- and 20-year was 97.8% (95.9-99.7%), 94.2% (91.0-97.4%), and 81.3% (74.8-88.3%), respectively. Overall survival approximated that of the general population (log-rank P=0.32). The cumulative incidence (with 95% confidence intervals) of any autograft or homograft reintervention at 10-, 15-, and 20-year was 16% (12-20%), 28% (21-35%), and 45% (36-54%), respectively.

CONCLUSIONS

The Ross procedure restores a normal life expectancy to young and middle-aged adults with severe aortic valve disease. The need for reintervention increases steadily during the second decade after the Ross procedure, but less than half of patients require any reintervention for up to 20-year.

Subcoronary Ross/Ross-Konno operation in children and young adults: initial single-centre experience

OBJECTIVES

We sought to evaluate the outcome after modified subcoronary Ross/Ross-Konno operation in children and young adults.

METHODS

Between January 2013 and January 2019, a total of 50 patients with median age of 6.3 years (range 0.02-36.5 years, 58% males), including 10 infants (20%), received modified subcoronary Ross/Ross-Konno operation at our institution. Survival, morbidity, reinterventions, aortic valve function and aortic root dimensions were analysed.

RESULTS

At a median follow-up of 31.2 months (range 14.4-51 months), there were 1 early death and 1 late death, both in the infant group. The overall survival at 5 years after the operation was 95%. Two patients needed aortic valve replacement, 11 and 15 months after their Ross operation. At 5 years, freedoms from reoperation on the autograft and on the right ventricle to pulmonary artery conduit were 94% and 97%, respectively. Freedom from aortic valve regurgitation greater than mild was 97% at 5 years. Median dimensions of the aortic root at all levels remained in normal range at last visit. Forty-four patients (95%) were in New York Heart Association class I with normal left ventricular function.

CONCLUSIONS

The initial experience with the subcoronary Ross/Ross-Konno operation in children and young adults showed excellent outcome. The mortality and morbidity among infants remain significant. The described technique is reproducible and might be advantageous in situations when prosthetic supporting techniques interfere with somatic growth.

Valve performance classification in 630 subcoronary Ross patients over 22 years

OBJECTIVE

To define the function of the "Ross valves" and its clinical meaning in a practical valve performance classification as part of the outcome analysis.

METHODS

From 1994 to 2017, 630 consecutive patients underwent the subcoronary Ross procedure at our institution. The valve performance classification combines hemodynamics, symptoms, and management criteria. Median follow-up was 12.5 years (maximum 22.3 years, 7404 patient-years, 99.4% completeness).

RESULTS

The mean age of the patients was 44.7 ± 11.9 years. Hospital deaths was 0.3% (n = 2). Twenty years after the operation survival was 73.1% (95% confidence interval [CI], 65.4%-81.6%) and statistically not different from the age- and gender-matched general population; freedom from reoperation was 85.9% (95% CI, 80.2%-92.0%; 0.6% per patient-year), 89.8% (95% CI, 84.3%-95.7%) for autograft, and 91.0% (95% CI, 86.3%-96.0%) for homograft. Preoperative annulus diameter, aortic regurgitation, annulus reinforcement, sinotubular junction reinforcement, and bicuspid aortic valve type were no significant risk factors for reoperation. At 20 years the probability of a patient being in valve performance class I to IV was 5%, 74%, 19%, and 1%, respectively. Time to reoperation was not different in bicuspid and tricuspid aortic valves; preoperative aortic stenosis tended to have better outcome of autograft function.

CONCLUSIONS

These up to 22 years data show that the subcoronary Ross procedure continues to provide an excellent tissue aortic valve replacement. The suggested valve performance classification emerged as a practical concept for outcome analysis with the probability of 79% being in the favorable class I or II at 20 years.

Pulmonary autograft in aortic position: is everything known?

The Ross operation provides several advantages compared to other valve substitutes to manage aortic valve disease, such as growth potential, excellent hemodynamics, freedom from oral anticoagulation and hemolysis, and better durability. However, progressive dilatation of the pulmonary autografts after Ross operation reflects the inadequate remodeling of the native pulmonary root in the systemic circulation, which results in impaired adaptability to systemic pressure and risk of reoperation after the first decade. A recently published article showed that remodeling increased wall thickness and decreased stiffness in the failed specimens after Ross operation, and the increased compliance might play a key role in determining the progressive long-term autograft root dilatation. Late dilatation can be counteracted by an external barrier which prevents failure. Therefore, an inclusion cylinder technique with a native aorta or a synthetic external support, such as Dacron, might stabilize the autograft root and improve long-term outcomes. In this article, we offer a prospective about the importance of biomechanical features in future developments of the Ross operation. Pre-clinical and clinical evaluations of the biomechanical properties of these reinforced pulmonary autografts might shed new light on the current debate about the long-term fate of the pulmonary autograft after Ross procedure.

Biomechanics of Failed Pulmonary Autografts Compared With Normal Pulmonary Roots

BACKGROUND

Progressive dilatation of pulmonary autografts after the Ross operation may reflect inadequate remodeling of the native pulmonary root to adapt to systemic circulation. Understanding the biomechanics of autograft root dilatation may aid designing strategies to prevent dilatation. We have previously characterized normal human pulmonary root material properties; however, the mechanical properties of failed autografts are unknown. In this study, failed autograft roots explanted during reoperation were acquired, and their material properties were determined.

METHODS

Failed pulmonary autograft specimens were obtained from patients undergoing reoperation after the Ross operation. Fresh human native pulmonary roots were obtained from the transplant donor network as controls. Biaxial stretch testing was performed to determine tissue mechanical properties. Tissue stiffness was determined at patient-specific physiologic stresses at pulmonary pressures.

RESULTS

Nonlinear stress-strain response was present in both failed autografts and normal pulmonary roots. Explanted pulmonary autografts were less stiff than were their native pulmonary root counterparts at 8 mm Hg (134 ± 42 vs 175 ± 49 kPa, respectively) (p = 0.086) and 25 mm Hg (369 ± 105 vs 919 ± 353 kPa, respectively) (p = 0.006). Autograft wall stiffness at both 8 and 25 mm Hg was not correlated with age at the Ross procedure (p = 0.898 and p = 0.813, respectively) or with time in the systemic circulation (p = 0.609 and p = 0.702, respectively).

CONCLUSIONS

Failed pulmonary autografts retained nonlinear response to mechanical loading typical of healthy human arterial tissue. Remodeling increased wall thickness but decreased wall stiffness in failed autografts. Increased compliance may explain progressive autograft root dilatation in autograft failures.

Long-term results of the Ross operation: an 18-year single institutional experience

OBJECTIVES

The purpose of the study was to assess the 18-year outcome of the Ross operation (RO), with emphasis on survival, reoperations, and late function of the pulmonary autografts (PAs) and the right-sided pulmonary allografts.

METHODS

Between May 1995 to July 2013, 414 patients with a mean age (mean ± standard deviation) of 30.8 ± 13.1 years were submitted to an RO with the root replacement (n = 356) or the inclusion (n = 58) technique. The most prevalent aetiology was bicuspid valve (n = 206, 49.8%). Patients were divided in four groups depending on the type of allograft used on the right side. The mean follow-up was 8.2 ± 5.2 years and was 97.7% complete. In addition to longitudinal outcomes determined by means of the Kaplan-Meier analysis, log-rank test and Cox regression analysis were used to identify predictors of valve failure.

RESULTS

The early mortality rate was 2.7% and the late survival rate was 89.3% at 15 years, similar to an age- and sex-matched population. There were 22 reoperations on the PA (90.7% freedom at 15 years) and 15 on the pulmonary allografts (92.5% freedom at 15 years). The freedom rate from more than mild aortic insufficiency (AI) was 73.1% at 15 years. Thirty-three patients presented with a late root diameter >45 mm, corresponding to a freedom rate of 72.4% at 15 years. Patients with AI and a dilated annulus, especially males, are at greater risk for these complications. Among the right-sided allografts, fresh decellularized allografts showed significantly superior freedom from structural valve dysfunction.

CONCLUSIONS

The RO was associated with excellent long-term survival and low incidence of reoperations up to 15 years. Male patients with AI and dilated annulus are at increased risk for late insufficiency and root dilatation. Fresh decellularized allografts presented the best results for reconstruction of the right ventricular outflow tract.

The Ross procedure: outcomes at 20 years

OBJECTIVES

Our study examines the outcomes of the Ross procedure in a cohort of 212 patients prospectively followed with clinical and echocardiographic assessments.

METHODS

Patients' mean age was 34 ± 9 years; 66% were men and 82% had congenital aortic valve disease. The median follow-up was 13.8 years. Patients who had reoperations continued to be followed and entered into the survival analysis.

RESULTS

There was 1 operative death as well as 9 late deaths (3 in patients who no longer had the Ross). Survival at 20 years was 93.6% and similar to the general population matched for age and sex. Fifteen patients required reoperations on the pulmonary autograft (4 repairs and 11 replacements), 8 on the pulmonary homograft, and 4 other cardiac procedures. At 20 years the freedom from reoperation on the pulmonary autograft was 81.8% and on the pulmonary homograft was 92.7%, and in both was 79.9%. Preoperative aortic insufficiency, aortic annulus diameter ≥15 mm/m(2), and being a man were associated with increased risk of reoperation on the pulmonary autograft. Twenty-six patients developed aortic insufficiency greater than mild and 25 patients developed pulmonary homograft dysfunction (defined as moderate or severe insufficiency and/or peak systolic gradient of >40 mm Hg). At 20 years the freedom from aortic insufficiency was 62.6% and freedom from pulmonary valve dysfunction was 53.5%.

CONCLUSIONS

Survival after the Ross procedure in this cohort was similar to the general population. Dilated aortic annulus and aortic insufficiency were associated with increased risk of developing aortic insufficiency. Pulmonary homograft dysfunction was common at 20 years.

Pulmonary autograft leaflet repair and valve sparing root replacement to correct late failure of the ross procedure

Delayed pulmonary autograft failure is the principal limitation of the Ross procedure. Although reoperation typically includes replacement of the neoaortic valve, strategies for autograft valve preservation are becoming increasingly employed. However, leaflet prolapse and asymmetry are deterrents to valve preservation in this technically complex surgical population. The present report illustrates the technical considerations in performing an autograft valve preserving aortic root replacement with direct leaflet repair for the surgical correction of aortic insufficiency and root aneurysm late after a successful Ross procedure.