Outcome of Pulmonary Autograft After the Ross Procedure

Ross procedure or mechanical aortic valve, which is the best lifetime option for an 18-year-old? A decision analysis

Objectives

Identifying the optimal solution for young adults requiring aortic valve replacement (AVR) is challenging, given the variety of options and their lifetime complication risks, impacts on quality of life, and costs. Decision analytic techniques make comparisons incorporating these measures. We evaluated lifetime valve-related outcomes of mechanical aortic valve replacement (mAVR) versus the Ross procedure (Ross) using decision tree microsimulations modeling.

Methods

Transition probabilities, utilities, and costs derived from published reports were entered into a Markov model decision tree to explore progression between health states for hypothetical 18-year-old patients. In total, 20,000 Monte Carlo microsimulations were performed to model mortality, quality-adjusted-life-years (QALYs), and health care costs. The incremental cost-effectiveness ratio (ICER) was calculated. Sensitivity analyses was performed to identify transition probabilities at which the preferred strategy switched from baseline.

Results

From modeling, average 20-year mortality was 16.3% and 23.2% for Ross and mAVR, respectively. Average 20-year freedom from stroke and major bleeding was 98.6% and 94.6% for Ross, and 90.0% and 82.2% for mAVR, respectively. Average individual lifetime (60 postoperative years) utility (28.3 vs 23.5 QALYs) and cost ($54,233 vs $507,240) favored Ross over mAVR. The average ICER demonstrated that each QALY would cost $95,345 more for mAVR. Sensitivity analysis revealed late annual probabilities of autograft/left ventricular outflow tract disease and homograft/right ventricular outflow tract disease after Ross, and late death after mAVR, to be important ICER determinants.

Conclusions

Our modeling suggests that Ross is preferred to mAVR, with superior freedom from valve-related morbidity and mortality, and improved cost-utility for young adults requiring aortic valve surgery.

Mechanical and Structural Adaptation of the Pulmonary Root after Ross Operation in a Murine Model

Background: The major limitation to the Ross operation is a progressive autograft dilation, possibly leading to reoperations. A murine model was created to evaluate pulmonary artery graft (PAG) adaptation to pressure overload. Methods: Lewis rats (n = 17) underwent heterotopic surgical implantation of a PAG, harvested from syngeneic animals (n = 17). A group of sham animals (n = 7) was used as a control. Seriated ultrasound studies of the PAG were performed. Animals were sacrificed at 1 week (n = 5) or 2 months (n = 15) and the PAG underwent mechanical and histopathological analyses. Results: Echography showed an initial increase in diameter (p < 0.001) and a decrease in peak systolic velocity (PSV). Subsequently, despite no change in diameter, an increase in PSV was observed (p < 0.01). After 1 week, the stiffness of the PAG and the aorta were similar, while at 2 months, the PAG appeared more rigid (p < 0.05). PAG’s histological analysis at 2 months revealed intimal hyperplasia development. The tunica media showed focal thinning of the elastic lamellae and normally distributed smooth muscle cells. Conclusions: We demonstrated a stiffening of the PAG wall after its implantation in systemic position; the development of intimal hyperplasia and the thinning of the elastic lamellae could be the possible underlying mechanism.

Prevalence and risk of progressive aortic aneurysm and dissection in adults with conotruncal anomalies

AIMS

Conotruncal anomalies share common embryogenic defects of the outflow tracts and great arteries, which result in a predisposition to aortic aneurysms. The purpose of this study was to describe the prevalence and risk of progressive aortic aneurysms in adults with conotruncal anomalies.

METHODS AND RESULTS

Retrospective study of adults with conotruncal anomalies that underwent cross-sectional imaging 2003-20. Aneurysm was defined as aortic root/mid-ascending aorta >2.1 mm/m2/>1.9 mm/m2, progressive aneurysm as increase by >2 mm, and severe aneurysm as dimension >50 mm. Of 2261 patients (38 ± 12 years; male 58%), 1167 (52%) had an aortic aneurysm, and 205 (14%) had a severe aortic aneurysm. Mean annual increase in aortic root/mid-ascending aorta was 0.3 ± 0.1 mm/0.2 ± 0.1 mm. The 3-, 5-, and 7-year cumulative incidence of the progressive aortic aneurysm was 4%, 7%, and 9%, respectively. The rate of aneurysm growth decreased with age, with no significant growth after age 40 years. There was an excellent correlation between aortic indices from cross-sectional imaging and echocardiography. Of 950 females, 184 had ≥1 pregnancy, and 81 (44%) of the 184 patients had aortic aneurysm prior to pregnancy. There was no aortic dissection or progression of the aortic aneurysm during pregnancy. Overall, there was no aortic dissection during 7984 patient-years of follow-up.

CONCLUSIONS

Aortic aneurysm was common in patients with conotruncal anomalies. However, the risk of progressive aneurysm or dissection was low. Collectively, these data suggest a benign natural history and perhaps a less frequent need for cross-sectional imaging. Further studies are required to determine the optimal timing for surgical intervention in this population.

Short- and Mid-Term Autograft Outcomes Following the Reinforced Ross Operation

BACKGROUND

The Ross operation for aortic valve replacement continues to be a controversial option because of concerns related to late autograft dilation and progressive neo-aortic insufficiency. In 2005, the reinforced Ross procedure was described at our institution to address this problem. We aim to analyze the short and mid-term outcomes following this procedure.

METHODS

This is a retrospective study of patients who underwent the reinforced Ross operation between 2004 and 2019. A comprehensive chart review was performed. Echocardiograms were independently reviewed by an adult congenital cardiologist. The time to reintervention was evaluated with a Kaplan-Meier curve. Analysis was conducted in JMP 15.1 (SAS Inc., Cary, NC).

RESULTS

Twenty-five patients underwent the reinforced Ross operation. Twenty-three patients (92%) had bicuspid aortic valve and the most common indication for surgery was a combination of aortic insufficiency and stenosis (n = 18, 72%). The mean follow-up was 6.1 ± 5.0 years. All patients were alive at the time of follow-up. Six patients (24%), from early in our experience, required subsequent aortic reintervention. Median time to reintervention was 41.8 months (0-81.5 months). Sixteen (64%) patients had less than moderate aortic insufficiency at last follow-up. Additionally, average aortic root measurements remained unchanged.

CONCLUSIONS

The reinforced Ross technique was initially proposed as a way to mitigate aortic root dilation seen in the traditional Ross procedure. Our experience suggests an associated learning curve with the majority of aortic reinterventions occurring within the first few years following surgery. Continued follow-up is warranted to assess its long-term durability and functionality.

Autograft Root Dilation After the Ross Procedure Is Not Benign

Autograft root dilation is common after the unsupported Ross procedure. In the absence of valvar incompetence, and with the perception that dissection is exceedingly rare, expectant management of autograft aneurysm is common practice. Autograft dissection may not be as rare as thought though, as at this point 7 case reports have accrued that describe autograft dissection requiring urgent operative intervention. All had a bicuspid native aortic valve. Bicuspid aortic valve has been shown to be associated with an intrinsic, histologically demonstrated pulmonary arteriopathy, possibly contributing to autograft root dilation and dissection. Autograft root dilation can no longer be regarded as benign, especially in patients with bicuspid aortic valve. Mounting evidence further validates the practice of externally supporting the Ross autograft. For patients who have had an unsupported Ross procedure, mounting evidence may support earlier intervention for autograft root dilation and aneurysm.