Decellularized Versus Standard Pulmonary Allografts in the Ross Procedure: Propensity-Matched Analysis.

BACKGROUND: It is hypothesized that decellularization of allografts used for right ventricular outflow tract reconstruction may result in decreased valve deterioration. This study compared the durability of fresh decellularized pulmonary allografts with standard cryopreserved pulmonary allografts in patients undergoing the Ross procedure. METHODS: The Ross procedure was performed in 144 patients with decellularized allografts (DA) from 2005 to 2014 and in 619 with standard cryopreserved allografts (SCA) from 1990 to 2014. Propensity score matching was used to compare early and midterm clinical outcome and echocardiographic allograft function over time between the two groups. RESULTS: We matched 94 DA patients (79.3% male; median age, 34.0 years; mean follow-up, 2.4 ± 1.9 years) to 94 SCA patients (78.3% male; median age, 35.0 years; mean follow-up, 9.4 ± 4.2 years). There were no significant differences in baseline characteristics after matching. The matched DA vs SCA groups, respectively, were comparable in actuarial 5-year freedom from allograft dysfunction (85.6% [95% confidence interval {CI}, 53.9% to 96.2%] vs 93.3% [95% CI, 85.7% to 96.9%], p = 0.892), freedom from allograft reintervention (98.8% [95% CI, 91.7% to 99.8%] vs 95.5% [95% CI, 88.5% to 98.3%], p = 0.383), survival (95.3% [95% CI, 87.8% to 98.2%] vs 97.7% [95% CI, 91.3% to 99.4%], p = 0.323), and event-free survival (83.5% [95% CI, 70.6% to 91.1%] vs 84.5% [95% CI, 75.2% to 90.5%], p = 0.515). Longitudinal echocardiographic analyses showed a similarly modest increase in allograft gradient and regurgitation grades over time in both groups, although direct statistical comparison was not possible. CONCLUSIONS: Up to 5 years of follow-up, DA and SCA used for right ventricular outflow tract reconstruction in the Ross procedure are associated with comparably excellent clinical and hemodynamic outcome. Longer follow-up and dedicated echocardiographic studies will shed light on the long-term performance of DAs.

The early and midterm function of decellularized aortic valve allografts.

BACKGROUND: This study evaluates the early and midterm results of decellularized aortic valve allografts (DAVA) as an aortic valve replacement. METHODS: Between October 2005 and February 2010, 41 patients, 28 of whom were male, with a median age of 34 years (range, 0.1 to 71), had aortic valve replacement with DAVA. Decellularization was obtained with a 0.1% sodium dodecyl sulfate solution. Postoperative evaluation was performed with serial echocardiograms, magnetic resonance imaging, and multislice computed tomography studies to evaluate valve hemodynamics, allograft conduit dimensions, and calcification scores. RESULTS: There were 3 early deaths and 1 late death, with a mean follow-up of 19 months (range, 1 to 53). There was 1 reoperation due to a failed mitral valve repair. By echocardiography in all patients, the median immediate postoperative peak gradient was 7 mm Hg (range, 1 to 26 mm Hg), and at last follow-up it was 4 mm Hg (range, 1 to 16 mm Hg); valvular regurgitation was graded as none or trivial in all but 1 patient, who had a regurgitation graded as mild to moderate. By magnetic resonance imaging (n = 4), mean root dimensions were stable at the annulus (24 mm), sinus of Valsalva (33 mm), and sinotubular junction (28 mm). By computed tomography (n = 22), there was only discrete conduit calcification (median calcium score 63 Hounsfield units [HU]; range, 0 to 894 HU) to 3 years of follow-up. Conduit biopsy in the patient who underwent reoperation demonstrated well-preserved wall structure, absence of calcification, and limited in vivo host repopulation. CONCLUSIONS: The early and midterm results with DAVA demonstrated stable structural integrity, low rate of calcification, and adequate hemodynamics. Although longer periods of observation are necessary, DAVA appears to be a promising alternative for aortic valve replacement in selected patients.

Thirteen years' experience with the Ross Operation.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate 13 years' results of the Ross operation, with special attention paid to the late function of the pulmonary autograft (PA) and the right ventricular outflow tract (RVOT) allograft, in an attempt to identify risk factors that might significantly influence their late performance. METHODS: Between May 1995 and March 2006, a total of 272 patients (mean age 30 +/- 11 years) was submitted to a Ross operation at the authors' institution. The most prevalent etiology was rheumatic disease (47%). The PA was implanted as a root replacement in 236 cases, and as an intraluminal cylinder in 36. The RVOT was reconstructed with a cryopreserved allograft in conventional fashion (n=142), with a proximal extension of the allograft with pericardium (n=46), with an allograft decellularized with deoxycholic acid (n=39), or an allograft decellularized with sodium dodecylsulfate (SDS) (n=44). The mean follow up was 67 months (range: 1-153 months: the total follow up was 1,525 patient-years. RESULTS: Hospital mortality was 2.9% and late survival 93% at 12 years. There were two episodes of cerebral thromboembolism, and six patients developed bacterial endocarditis. Sixteen patients required reoperation for problems involving the PA and/or the RVOT allograft, progression of rheumatic mitral valve disease and iatrogenic coronary insufficiency. After 12 years, 97% and 95% of patients were free from reoperation with the PA and allograft, respectively. Over time, the PA showed increasing dimensions, and 10 patients had a diameter >45 mm. Univariate analysis revealed degenerative disease and aortic annulus >25 mm as significant risk factors for late PA dilatation. Female gender and bicuspid aortic valve were borderline factors for this type of complication. Another 14 patients had late moderate PA insufficiency, and this was correlated with a preoperative diagnosis of aortic insufficiency. Reconstruction of the RVOT with allografts decellularized with SDS were associated with lower gradients at late follow up. CONCLUSION: Late results with the Ross operation were associated with excellent long-term survival and a low incidence of reoperations up to 13 years. Due to late PA dilatation and/or progressive valvar insufficiency, some reoperations may be expected with a longer follow up. For the RVOT reconstruction, the use of decellularized allografts with SDS may prove to be a good alternative to RVOT reconstruction.