Preservation of the pulmonary autograft after failure of the Ross procedure

Autograft reoperations after the Ross procedure

OBJECTIVES

After a Ross procedure, autograft failure can occur. At reoperation, repair of the autograft preserves the advantages of the Ross procedure. The aim of this retrospective study was to assess mid-term results after reoperation of a failed autograft.

METHODS

Between 1997 and 2022, 30 consecutive patients (83% male; age 41 ± 11 years) underwent autograft reintervention between 60 days and 24 years (median 10 years) after a Ross procedure. The initial technique varied, full-root replacement (n = 25) being the most frequent. The indication for reoperation was isolated autograft regurgitation (n = 7), root dilatation (>43 mm) with (n = 17) or without (n = 2) autograft regurgitation, mixed dysfunction (n = 2) and endocarditis (n = 2). In 4 instances, the valve was replaced by valve (n = 1) or combined valve and root replacement (n = 3). Valve-sparing procedures consisted of isolated valve repair (n = 7) or root replacement (n = 19), and tubular aortic replacement. Cusp repair was performed in all but 2. Mean follow-up was 5.4 ± 6 years (35 days to 24 years).

RESULTS

Mean cross-clamp and perfusion times were 74 ± 26 and 132 ± 64 min. There were 2 perioperative deaths (7%; both valve replacement) and 2 patients died late (32 days to 1.2 years postoperatively). Freedom from cardiac death at 10 years was 96% after valve repair and 50% after replacement. Two patients required reoperation (1.68 and 16 years) following repair. One underwent valve replacement for cusp perforation, the other, root remodelling for dilatation. Freedom from autograft reintervention at 15 years was 95%.

CONCLUSIONS

Autograft reoperations after the Ross procedure can be performed as valve-sparing operations in the majority of cases. With valve-sparing, long-term survival and freedom from reoperation are excellent.

Aortic valve repair in the pediatric population: emerging role of aortic valve neocuspidization (AVNeo procedure)

Management of aortic valve diseases in children is challenging owing to the quality and quantity of the native tissue for repair, limitations in the currently available biological materials to supplement the repair and to achieve a long-lasting durable repair in an annulus where there is still growth potential. The aortic valve neocuspidization (AVNeo) procedure has emerged as a versatile alternative strategy in the armamentarium of pediatric aortic valve reconstructions that are currently available. In this review article, the focus of the discussion will be on the various aortic valve repair procedures in the pediatric population, with a special emphasis on the emerging role of AVNeo procedure in pediatrics and its outcomes.

Ross Operation in Pediatric Population: Impact of the Surgical Timing and the Native Pulmonary Diameter on the Outcome

Aortic valve replacement early in life may be inevitable. Ross operation, until present day, remains the favorite surgical option in pediatrics with irreparable aortic valve disease. Nonetheless, the necessity for re-operation was always its principal limitation due to aortic valve failure or homograft degeneration. We present our 25 years of experience in the pediatric population. From August 1994 until June 2018, 157 children below 18 years underwent the Ross operation. This retrospective review aims at assessing the long-term outcomes, as well as the risk factors for re-operation after Ross procedure. Median age was 10.9 years, of which seven patients were infants, 79 children, and 71 adolescents. The median follow-up time was 14 years. Hospital mortality was 0.6%. Freedom from autograft re-operation for children was 96.7% and 94.1% at 10 and 20 years, respectively; whereas for adolescents, it was 92.6% and 74.9% at 10 and 20 years. For children, freedom from homograft re-operation was 92.5%, 83.5%, and 56.2% at 10, 15, and 20 years; while for adolescents, it was 96.8%, 91.8%, and 86.7% at 10, 15, and 20 years. Homograft size (p = 0.008) and childhood (p = 0.05) were risk factors for homograft re-operation. Pulmonary valve diameter > 24 mm (p = 0.044) and adolescence (p = 0.032) were risk factors for autograft re-operation. Our experience demonstrated excellent early and late survival. While children have preferential outcomes concerning autograft re-operation, those who received a smaller homograft had a higher right-sided re-intervention incidence than adolescents. Pulmonary diameter > 24 mm at surgery was an indicator of future autograft failure.

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.

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.

AUTOGRAFT WRAPPING REINFORCEMENT IN ADOLESCENTS UNDERWENT ROSS OPERATION: A TAILORED COAT

BACKGROUND

The Ross operation is a good surgical option for pediatric population with aortic valve disease. However, the need for reoperation due to aortic root dilatation remains the principal limitation of this procedure. We report a small series of adolescents who underwent the Ross operation with goretex membrane reinforcement to avoid the progressive dilatation of the neo-aortic root.

METHODS

Between March 2002 and March 2010, 15 adolescent patients underwent a modified Ross procedure with the autograft wrapping with Gore® Preclude® pericardial membrane 0.1 mm. Follow-up was performed by clinical and echocardiographic controls.

RESULTS

The mean age of these patients was 15 ± 1.4 years. The mean aortic cross-clamp time was 130 ± 17 minutes. The mean cardiopulmonary bypass time was 187 ± 27 minutes. There was no hospital mortality. The mean follow-up was 15 ± 2.5 years (range 9.7-17.7 years). During the follow-up one patient required aortic valve reoperation for cusps prolapse. The mean diameters of annulus (22.8 ± 1.8 mm vs 23.3 ± 1.5 mm, p=0.12), aortic root (27.4±1.4 mm vs 28.2 ± 0.8 mm, p=0.09) and sino-tubular junction (24.3 ± 1.1 mm vs 25.1 ± 0.7 mm, p=0.11) were not statistically different between discharge and follow up.

CONCLUSIONS

The wrapping reinforcement autograft in Ross procedure with goretex membrane is simple, safe and does not require significant additional time. Our results showed good early and long-term outcomes in terms of reoperation, aortic root dilatation and aortic valve degeneration.

Mid-term Outcome of 100 Consecutive Ross Procedures: Excellent Survival, But Yet to Be a Cure

The Ross procedure offers excellent short-term outcome but the long-term durability is under debate. Reinterventions and follow-up of 100 consecutive patients undergoing Ross Procedure at our centre (1993-2011) were analysed. Follow-up was available for 96 patients (97%) with a median duration of 5.3 (0.1-17.1) years. Median age of the patient cohort was 15.2 (0.04-58.4) years with 76 males. 93% had underlying congenital aortic stenosis. Root replacement technique was applied in all. The most common valved conduits used for reconstruction of the right ventricular outflow tract were homografts (66 patients) and bovine jugular vein (Contegra^R) graft (31 patients). Additional procedures included Ross-Konno procedure (14%), resection of subaortic stenosis/myectomy (11%) and reduction plasty of the ascending aorta (25%). One patient died within the first 30 days (1%). Late deaths occurred in 4 patients (4%) 0.5-4.5 years postoperatively: causes included pulmonary hypertension due to endocardial fibroelastosis (2), subarachnoid haemorrhage (1) and sudden cardiac death (1). Five-year survival was 93.6 (95% CI 88.1-99.1)%. Moderate or severe aortic (autograft) regurgitation needing reoperation occurred in 8 patients with a 5-year freedom from autograft reoperation of 98.5 (95.6-100)%. Five-year freedom from reintervention (surgery or catheter based) on the right ventricular outflow tract conduit was 91.5 (85.5-96.5)%. Univariate predictors of this reinterventions were smaller graft size (p = 0.03) and use of a Contegra^R graft (p = 0.04). Ross procedure can be performed with low mortality and good survival in the long term. Most of the reinterventions are related to the neo-right ventricular outflow tract and may be partly attributed to the lack of growth. While the Ross Procedure remains an invaluable option for aortic valve disease in children, new solutions for the neo-pulmonary valve as well as for the less often occurring problems on the autograft are needed.

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.

Oxidative Stress and Lung Ischemia-Reperfusion Injury

Ischemia-reperfusion (IR) injury is directly related to the formation of reactive oxygen species (ROS), endothelial cell injury, increased vascular permeability, and the activation of neutrophils and platelets, cytokines, and the complement system. Several studies have confirmed the destructiveness of the toxic oxygen metabolites produced and their role in the pathophysiology of different processes, such as oxygen poisoning, inflammation, and ischemic injury. Due to the different degrees of tissue damage resulting from the process of ischemia and subsequent reperfusion, several studies in animal models have focused on the prevention of IR injury and methods of lung protection. Lung IR injury has clinical relevance in the setting of lung transplantation and cardiopulmonary bypass, for which the consequences of IR injury may be devastating in critically ill patients.

The Ross procedure: suitable for everyone?

In 1967, Donald Ross transferred the patient's own pulmonary valve into the aortic root. Although results of this technique were encouraging, the Ross procedure did not gain widespread popularity until the late 1980s when surgeons started to implant the pulmonary autograft as a freestanding full root replacement with reimplantation of the coronary arteries. However, frequent dilatation of the pulmonary autograft was observed using the freestanding full root replacement technique. In contrast, the original subcoronary implantation technique and aortic root inclusion technique prevented dilatation in the long-term. Through advancing know-how in aortic root surgery and confidence, the Ross procedure has also been used in combined procedures and complex clinical presentations with good long-term results, which encourage continual use. However, the Ross procedure is a complex operation; careful patient selection and experience of the surgeon are mandatory requirements to achieve satisfactory results.

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.

The Ross procedure: state of the art 2011

The purpose of this paper is to review the current literature and practice of the Ross concept of using the autologous pulmonary valve to replace a diseased aortic valve. The potential advantages and disadvantages of these operations will be evaluated in the context of alternative options and relative risks. The different surgical techniques of subcoronary and full root methods will be discussed and important technical aspects reviewed. Long-term outcomes will be described to the extent these are available, including recent publications describing a survival advantage for the Ross. Brief discussions will be presented regarding hemodynamics, child-bearing, endocarditis, and the use of the Ross in pediatric patients as well as biological adaptability of the living pulmonary autograft.

Reoperation after the Ross procedure: incidence, management, and survival

BACKGROUND

The risk of reoperation on the autograft and homograft is the major long-term drawback of the Ross procedure. The incidence and clinical implications of reoperations after the Ross procedure are reported.

METHODS

Between March 1992 and February 2010, 336 consecutive patients had a Ross procedure (mean follow-up, 6.2±4.9 years). Autograft implant technique was freestanding root replacement in 269 patients, subcoronary implantation in 52 patients and a modified root replacement with the autograft included in a Valsalva tube graft in 15.

RESULTS

Subsequently, 38 patients (11.3%) underwent reoperations, for autograft dilatation in 23 and a significant autograft insufficiency in 9, at 9.6±3.7 years and 2.6±3.9 years, respectively. Aortic and pulmonary infective endocarditis occurred in 3 patients. Three patients underwent a non valve-related cardiac reoperation. Three patients received a transcatheter pulmonary valve implantation after 12.2±1.7 years. At 15 years, freedoms for autograft and homograft explantation (with 95% confidence interval) were 83.3% (77.4%- to 9.2%) and 92.8% (87.6% to 97.9%), respectively. Native aortic valve regurgitation, indexed aortic annulus diameter exceeding 1.35 cm/m2 and autograft diameter were risk factors for dilated autograft reoperation (hazard ratio, 3.23 [95% confidence interval, 1.19 to 8.81], p=0.02; 3.83 [0.9 to 16.33], p=0.07 and 1.2 per mm [1.01 to 1.41], p=0.03), respectively.

CONCLUSIONS

Autograft dilatation was the leading cause of reoperation in patients who underwent root replacement. Long-term follow-up is mandatory to determine whether modifications of the operative technique could limit autograft dilatation.

Treatment of congenital heart disease: risk-reducing measures in young adults

Adults with congenital heart disease form a new and relatively young population, since surgical treatment of heart defects became available three to four decades ago. Owing to improved survival this population is steadily growing in number and age. Little is known regarding long-term survival; however, late complications occur frequently. During adulthood, almost half of the patients have one or more complication, such as endocarditis, stroke, systemic or pulmonary hypertension, aortic aneurysm or dissection and arrhythmias. Heart failure and sudden cardiac death are the main causes of death. Treatment of adults with congenital heart disease is aimed at the reduction of symptoms, but also at minimizing the risk and severity of late complications. In this article the most recent advances in the treatment of congenital heart disease will be discussed. The main focus of the article will be on pharmacological, interventional and surgical interventions that reduce the risk of heart failure, arrhythmias, vascular complications, pulmonary hypertension and endocarditis.

Aortic reoperation after freestanding homograft and pulmonary autograft root replacement

BACKGROUND

Human allografts and pulmonary autografts offer many advantages as an aortic valve and root substitute. The progressive degeneration of the aortic allograft and the pulmonary autograft has been seen as an important disadvantage, and the need for a reoperation has been perceived as challenging and risky for the patients.

METHODS

Between March 1992 and October 2009, 53 consecutive patients (mean age 50 ± 13 years; 38 male), who had a previous aortic root replacement, underwent redo surgery for failure of the aortic homograft (n = 42) or the pulmonary autograft (n = 11). The median follow-up (available for 47 of 51 patients) was 44 months.

RESULTS

Structural valve deterioration was the main indication for reoperation on the homograft (86%), with an earlier presentation in patients who received homografts from donors more than 55 years old. Failure of the pulmonary autograft occurred primarily because of severe aortic regurgitation predominantly due to dilation of the autograft (n = 5) and autograft valve prolapse (n = 5). The total in-hospital mortality was 3.8% (n = 2). No deaths occurred among patients who previously underwent a Ross procedure. The course was complicated in 25 cases (48%). The cumulative 1-year, 5-year, and 8-year survival rates were 92%, 90%, and 77%, respectively. No late deaths were encountered after reoperation on the pulmonary autograft (maximum follow-up 218 months). Freedom from reoperation (excluding early in-hospital operation) for recurrent aortic valve or root pathology was 97% at 8 years.

CONCLUSIONS

Reoperation after freestanding homograft and pulmonary autograft root replacement can be accomplished safely. The total postoperative morbidity rate is still high.