We carried out a retrospective observational single-center analysis that included all consecutive patients (aged ≥16 years) who underwent a Ross procedure in our institution between January 1992 and December 1999. Patients under 16 years old were excluded since other associated congenital defects are often present and the prognosis is different from adults.8

In total, 56 patients were included. Data on patient and surgery characteristics were obtained from hospital medical records and the surgical database.

The choice of the Ross procedure as an alternative treatment for aortic valve disease was discussed with all patients with an active lifestyle and a desire to avoid lifelong anticoagulation therapy. Surgery was performed after informed consent was obtained. The surgical technique has been described previously.12 Briefly, all patients were operated under standard cardiopulmonary bypass (CPB) conditions with moderate systemic hypothermia, and cardioplegia was administered by anterograde and retrograde infusion. The pulmonary valve was explanted after careful inspection of its structure, and right ventricle to pulmonary artery continuity was re-established using a cryopreserved pulmonary homograft from a local heart valve bank. Two operative techniques were used to implant the autologous pulmonary valve in the aortic position: subcoronary implantation and aortic root replacement (partial with implantation of one coronary artery or total with implantation of both coronaries).12,13 Although the subcoronary technique was more often used (n=48; 86%), the choice between the two main Ross procedure techniques was dependent on aortic root and pulmonary size, presence of aortic root disease, coronary artery anatomy and the surgeon's preference.14

From August 1996, detailed measurements of the pulmonary and aortic valve leaflets were routinely performed in surgery to choose the correct orientation of the pulmonary autograft in relation to the recipient aortic root. Our group has previously reported a method to determine the best fitting position for the autograft in the aortic root that would cause the least distortion and possibly less regurgitation after surgery.15

Intraoperative transesophageal echocardiography was performed in all patients, before and after CPB, to assess the morphology and function of both autograft and homograft and also possible complications, particularly related to left ventricular systolic function. Before discharge from hospital, all patients underwent transthoracic echocardiography.

Clinical follow-up was performed by the referring cardiologists. Follow-up data were collected from hospital medical records or, if clinical follow-up was performed in a different hospital, by phone contact with the referring cardiologist, patient or family member. Vital status and date of death were obtained from the national registry. Echocardiographic assessments were scheduled according to the preference of the patient's cardiologist.

Clinical follow-up was complete in all patients. Patients who were reoperated on the AV continued to be monitored and were included in the survival analysis, but were excluded from the echocardiographic analysis. Overall, all patients who were alive and who were not reoperated on the homograft or autograft had echocardiographic follow-up (71% performed in our center).

The clinical endpoints were overall mortality and valve reoperation due to graft failure (any surgical intervention performed due to autograft or homograft degeneration or endocarditis). The echocardiographic endpoint was defined as graft dysfunction with at least moderate regurgitation or stenosis with a mean gradient of ≥20mmHg, in accordance with the European guidelines on valve disease.16 Quantification of aortic regurgitation as at least moderate was defined by the following criteria: effective regurgitant orifice area ≥10mm2 or regurgitant volume ≥30ml, pressure half-time ≤500ms, and ratio of aortic jet width to left ventricular outflow tract diameter >25%.

The survival rate of the study population was compared with that of the general population. Age, gender and surgery-year survival estimates for the general population were obtained from life tables published online by the Portuguese National Statistics Institute.

Continuous variables were described as mean ± standard deviation, or median and interquartile range (IQR) for variables with non-normal distribution. Categorical variables were represented as percentages. Normality of distribution was assessed with the Kolmogorov-Smirnov test. Cumulative rates of all-cause death and reoperation were estimated using the Kaplan-Meier method. The one-sample log-rank test was used for comparisons with the age- and gender-adjusted standard population. Two-sided p values <0.05 were considered statistically significant. The statistical analysis was performed with IBM SPSS version 22.0.

The preoperative clinical characteristics of the population and surgical data are shown in Tables 1 and 2, respectively. Ages ranged from 16 to 65 years (mean age 44 years) and 55% were male. The main etiologies of aortic disease were rheumatic (32%), bicuspid valve (29%) and calcified tricuspid (27%). The indication for surgery was stenosis in 50%, pure regurgitation in 21% and mixed aortic disease in 29% of cases. Most patients had preserved ejection fraction and concomitant mitral repair intervention was performed in 21%.

The subcoronary implantation technique was used in 86% of cases. Mean CPB time was 153±23min and median length of hospital stay was nine days (IQR: 7-10).

The median clinical follow-up was 20 years (IQR: 19-23; 1120 patients/year) and ranged from one to 24 years in all patients and from 16 to 24 years in living patients.

Overall survival, including those who were reoperated for any cause, was 93%, 91%, 80% and 77% at 10, 15, 20 years and the final follow-up, respectively (Figure 1). Overall 30-day mortality was one patient, due to hemorrhagic shock.

Figure 1.

Kaplan-Meier analysis of long-term outcomes after the Ross procedure (n=56). (A) Overall survival; (B) freedom from graft reoperation.

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No significant difference was observed between the survival of the Ross population and that of the age- and gender-adjusted standard population (one-sample log-rank test standard mortality ratio 1.24; 95% confidence interval: 0.67-2.28, p=0.44; Figure 2).

Figure 2.

Kaplan-Meier analysis of survival after the Ross procedure compared with an age- and gender-adjusted standard population.

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Freedom from reintervention due to graft failure was 87.5%, 82.1% and 80.4% at 15, 20 and 24 years, respectively. A total of 11 patients (19.6%) required graft-related reoperation after the initial Ross procedure. Kaplan-Meier curves for reintervention are shown in Figure 1.

The main indication for reoperation was severe autograft regurgitation, except for one patient with homograft stenosis. There was no concomitant replacement of the ascending aorta in patients who underwent reintervention. Eight patients required reoperation due to mitral and/or tricuspid disease.

In the subgroup of patients who underwent the subcoronary technique (n=48), the rate of reoperation was 13% (n=6) and 19% (n=9) at 15 and 24 years, respectively. There was a small difference in the reoperation rate compared with the much smaller group who underwent root replacement technique (19% vs. 25%, p=0.68 respectively), without statistical significance.

After discharge the incidence of stroke at follow-up was 7% (n=4), one of them related to endocarditis, and there was no hemorrhagic stroke. At the latest follow-up, 37 (86%) patients were in New York Heart Association functional class I, five (12%) in class II, and one (2%) in class III.

Median length of echocardiographic follow-up was 19 years (IQR: 17-21 years). Among patients who were not reoperated and who were alive at the end of follow-up (n=35), 11 patients (31%) had moderate and one had severe autograft regurgitation. In the other patients, autograft regurgitation was mild (n=20; 57%) or absent (n=3; 8.6%). No autograft stenosis was observed. Regarding the pulmonary homograft, only three patients had moderate regurgitation and the remainder had mild or no regurgitation. Four patients had mild and one patient had moderate stenosis (Figure 3). At 24 years, freedom from moderate or severe aortic regurgitation was 66%. Except from the patient with severe autograft regurgitation, there was no left ventricular dysfunction or dilatation.

Figure 3.

Valve deterioration after the Ross procedure in patients who were not reoperated and who were alive at the end of follow-up (n=35). (A) Regurgitation; (B) stenosis.

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By the end of follow-up, two patients had dilated aortic root combined with moderate secondary autograft regurgitation and five had isolated dilatation of the ascending aorta (45-50mm in three patients and >50mm in two).

Morphological assessment of the pulmonary cusp dimensions was performed in 17 patients (30%). There was no significant difference in reintervention rate (18% [n=3] vs. 21% [n=8], p=0.81) or incidence of moderate or severe aortic regurgitation in this subset of patients compared to the others.