Outcomes of Redo Operations after Ross procedure

Lifetime Management of Adolescents and Young Adults with Congenital Aortic Valve Disease

In this invited expert review, we focus on evolving lifetime management strategies for adolescents and young adults with congenital aortic valve disease, acknowledging that these patients often require multiple interventions during their lifetime. Our goal is to preserve the native aortic valve when feasible. Leveraging advanced multimodality imaging, a detailed assessment of the aortic valve and root complex can be obtained, and a surgically approach tailored to an individual patient's anatomy and pathology can be used. In turn, aortic valve repair and reconstruction can be offered to a greater number of patients, either as a definitive strategy or as a component of a staged strategy to delay the need for aortic valve replacement until later in life when more options are available.

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.

Outcomes of the Ross procedure in patients older versus younger than 50 years old

OBJECTIVES

The Ross procedure is traditionally considered for young adult patients with aortic valve disease. This study compares long-term outcomes of patients undergoing the Ross procedure who are ≥50 and <50-years old.

METHODS

Data were collected from 225 patients undergoing Ross procedure at a single centre from 1994 to 2019. Patients were categorized into younger (<50-years old; n = 156) and older (≥50-years old; n = 69) cohorts. Baseline demographics clinical outcomes were compared.

RESULTS

The mean age was 36 ± 8.1 and 55 ± 4.2 years in the younger and older cohort, respectively. Both groups were predominantly male (58.5% vs 69.6%; P = 0.59). The younger group had a higher rate of aortic insufficiency (51% vs 26.1%; P < 0.01), and bicuspid aortic valve (81.4% vs 58.0%; P < 0.01). Aortic stenosis was more prevalent in the older cohort (25.6% vs 58.0%; P < 0.01). Operative mortality was acceptable in both groups (1.3% vs 4.3%; P = 0.15). Survival up to 10 years was not statistically different between 2 groups (96.2% vs 91.3% P = 0.16), whereas survival up to 15 years for younger patients was significantly higher (94.9% vs 85.5%; P = 0.03). After non-cardiac related deaths were excluded, survival up to 15 years (98.7% vs 91.3%; P = 0.02) was significantly lower than younger patients. In both groups, survival after the Ross procedure was similar to the age- and sex-matched US population.

CONCLUSIONS

Survival up to 10 years after Ross procedure were similar, but up to 15 years was significantly higher in younger patients. The Ross procedure restored patients from both groups to expected survival. Our results suggest that at experienced centres, the Ross procedure is a safe and reasonable option for patients who are 50 years and older.

Effect of chemicals on the phase and viscosity behavior of water in oil emulsions

Due to population growth, the need for energy, especially fossil fuels, is increased every year. Since the costs of exploring new reservoirs and drilling new wells are very high, most reservoirs have passed their first and second periods of life, and it is necessary to use EOR methods. Water-based enhanced oil recovery (EOR) methods are one of the popular methods in this field. In this method, due to the possibility of emulsion formation is high, and by creating a stable emulsion, viscosity and mobility improved. In this study, the parameters affecting the stability and viscosity of the emulsion have been investigated step by step. In the first step, 50% (v/v) of water has been selected as the best water cut. The type of salt and its best concentration was evaluated in the second step by measuring the average droplets size. The third step investigated the effect of SiO2 nanoparticles and surfactant (span80) on emulsion stability and viscosity. According to the results, the best amount of water cut was 50% due to the maximum viscosity. In salts the yield was as follows: MgCl2 > CaCl2 > MgSO4 > Na2SO4 > NaCl. The best yield was related to MgCl2 at a concentration of 10,000 ppm. Finally, it was shown that the synergy of nanoparticles and surfactants resulted in higher stability and viscosity than in the case where each was used alone. It should be noted that the optimal concentration of nanoparticles is equal to 0.1% (w/w), and the optimal concentration of surfactant is equal to 200 ppm. In general, a stable state was obtained in 50% water-cut with MgCl2 salt at a concentration of 10,000 ppm and in the presence of SiO2 nanoparticles at a concentration of 0.1% and span 80 surfactants at a concentration of 200 ppm. The results obtained from this study provide important insights for optimal selection of the water-based EOR operation parameters. Viscosity showed a similar trend with stability and droplet size. As the average particle size decreased (or stability increased), the emulsion viscosity increased.