Ascending Aortoplasty in Pediatric Patients Undergoing Aortic Valve Procedures.
Tan CW, Marathe SP, Kwon MH, Chavez M, Friedman KG, Staffa S, Del Nido P, Baird CW.
Ann Thorac Surg. 2020 Sep 15:S0003-4975(20)31477-6. doi: 10.1016/j.athoracsur.2020.06.115. Online ahead of print.
Take Home Points:
- Ascending aortoplasty at the time of aortic valve surgery is safe and effective in reducing ascending aortic dimensions and recurrent aortic regurgitation in the short/intermediate term.
- Longer term follow up will be necessary to determine continued rate of growth.
Commentary from Dr. Jared Hershenson (Greater Washington DC), section editor of Pediatric Cardiology Journal Watch: It is well known that hemodynamic and genetic factors can result in aortic root and ascending aorta dilation in patients with aortic valve disease. There are relatively clear guidelines in the adult population for when to intervene on the aorta during or independent of aortic valve surgery. However, the morbidity and mortality, the risk of dissection, and the impact on progressive aortic regurgitation in pediatric patients with ascending aorta dilation based on z-score is not well known. This results in a lack of guidelines within the pediatric population for intervention. Reduction aortoplasty can immediately reduce the size of the aorta, but it is unclear if this will prevent future growth and decrease risk of dissection/rupture or prevent future aortic regurgitation. The current general trend has been to accept higher aortic dimensions, but this may be result in the significant mortality.
This was a retrospective study of patients between 2010-2018 who had an ascending aorta z-score of > +2 at the time of aortic valve surgery. Exclusions included patients with prior ascending aorta repair, single ventricle pathology, s/p ASO, heart transplant or known connective tissue disorder. 47 patients underwent aortoplasty with 39 having complete data points. They were compared with 39 matched controls. Echocardiograms pre-operatively, immediate post-operatively, and at latest follow up were reviewed for lateral ascending aorta dimensions in the PLAX and z-scores obtained based on BSA. The surgical technique was described in the paper and the goal was to reduce the ascending aorta size to a z-score between 0 and +2 or a decrease of at least 2 z-scores.
A total of 39 subjects with a median age of 11 years and weight of ~41 kg were compared to 39 controls, with only BSA being dissimilar. No patients required a 2nd cross clamp due to inappropriate reduction of the aorta. Ozaki type reconstruction of the aortic valve was more common in the aortoplasty group. Table 2 shows the operative and post-operative details of each group. Within the study group, pre-operative mean ascending aorta z-score was 5.35+/-1.52 and reduced to 1.22+/-1.63 post-operatively. 29/47 patients had a z-score < +2. For the 39 patients with all-time points, median follow up was 12.5 months and ascending aorta z-score remained similar at 1.37+/-1.72 (Figure 2).
Of the 12 patients with a post-operative z-score > +2, all remained with unchanged z-score (average change 0.14) at latest follow up. No differences in z-scores could be identified by aortic valve morphology, pathology or intervention, patient weight or BSA. In the control group, median follow up was 40.8 months. Pre-operative mean ascending z-score was 4.15+/-1.65 and was reduced to 3.26+/-2 at latest follow up that was deemed to be from greater somatic growth than aortic growth over time, resulting in a lower z-score. While the control group also had a significant reduction in average z-score, the reduction was significantly larger in the aortoplasty group (see Figure 3). The control group had 6.84 times the odds of moderate or greater aortic regurgitation (see Figure 4), and this was confirmed to not be related to type of aortic valve repair on secondary analysis. No patients in the aortoplasty group had any early post-operative complications.
The authors note that rapid aneurysmal growth did not occur after aortoplasty. Additionally, there may be even greater benefit in those patients with residual aortic valve disease and persistent hemodynamic effect on the ascending aorta. Limitations of this study include the small sample size, retrospective design, and relatively short follow up duration. Additionally, it would have been nice if the authors would have included aortic root z-scores (sinuses and STJ) as well as the ascending aorta, and it is unclear why they were not.
Hopefully, there will be longer term studies (greater than 10 years) and possibly including other imaging modalities (CT/MRI) looking at the absolute aortic dimensions and rate of change after aortoplasty. However, given the likely relatively low short and intermediate risk, as well as what seems to be a quite significant decrease in risk of progressive aortic regurgitation, it may be reasonable to consider aortoplasty in more patients.