Congenital Heart Surgery

Blood flow characteristics after aortic valve neocuspidization in paediatric patients: a comparison with the Ross procedure. Secinaro A, Milano EG, Ciancarella P, Trezzi M, Capelli C, Ciliberti P, Cetrano E, Curione D, Santangelo TP, Napolitano C, Albanese SB, Carotti A. Eur Heart J Cardiovasc Imaging. 2021 Feb 7:jeab009. doi: 10.1093/ehjci/jeab009. Online ahead of print.PMID: 33550364   Take Home Messages: The Ozaki procedure is an alternative to the Ross procedure for AVR in children. Short-term hemodynamics of the Ozaki procedure are reassuring. Long-term results of the Ozaki procedure are lacking.   Commentary from Dr. Frederic Jacques (Québec City, Canada), section editor of Congenital Heart Surgery Journal Watch:   Background: Aortic valve replacement in children is challenging. Durable prosthesis that allows growth are lacking. The Ross procedure, the actual preferred replacement strategy (creating a double valve concern), offers a reliable aortic valve substitute with growth potential, but it is not devoted of technical challenges and long-term complications. Because of these limitations, an alternative strategy was recently borrowed by congenital surgeons to adult cardiac surgery. This strategy, the Ozaki procedure, literally consists of fashioning a stentless bioprosthesis within the aortic root with pericardium. Said differently, it is a leaflet extension (the less durable aortic valve repair technique) with its origin on the annulus.   Summary: In order to define the hemodynamic repercussions of these two aortic valve replacement strategies on the aorta, Secinaro et al. recruited 20 patients (10 per group) and performed a Cardiac MRI to assess flow eccentricity and wall shear stress. They report their findings in the February issue of European Heart Journal - Cardiovascular Imaging. The mean age of patients was 11 years old in each group. Imaging was performed in average 3 years after the Ross procedure and 4 months after the Ozaki procedure. Maximal gradient through the aortic orifice was 7 mmHg for Ross’s patients and 21 mmHg for the Ozaki procedure. Noteworthy regurgitation was present in 40% of patients regardless of the procedure. At the sinotubular junction, 60% of Ross’ had mild eccentricity and 10% of Ozaki’s had marked eccentricity. The remaining had central flow. According to the authors, there was no difference in wall shear stress between the two procedures.   Comment: Even if the timing of the performance of the MRI is earlier for the Ozaki procedure group (i.e., less likely to be exposed to deterioration) the reader can appreciate that the hemodynamic performance of the valve (although still within the normal range) is already less favorable than with the Ross procedure. In fact, even though there is less patients with the Ozaki procedure showing mild eccentricity than with the Ross procedure, it shows marked eccentricity in some. Is this the reflection of the material used or is it the repercussions of the inability of surgeons to replicate the “perfection” of a normal native aortic valve? Once again, the Ozaki procedure could be fairly described as a bioprosthesis art crafted within the aorta with the clamp on. Nevertheless, the finding of this stress is in accordance with what is already known for structural degeneration of bioprosthesis and that of leaflet extension. Will this confer less durability to the Ozaki procedure compared to the Ross in the long-term? We will find in a few years. On the other hand, these findings are somewhat reassuring, at least for the short term, regarding the hemodynamics of the Ozaki procedure. Even if it does not beat alternatives such as the Ross, it may actually offer a safe transition to a more definitive surgical replacement (likely adult size manufactured prosthesis) at a later turn. If this is the case, it will already be a major addition to our armamentarium.   

Left heart growth and biventricular repair after hybrid palliation. Sojak V, Bokenkamp R, Kuipers I, Schneider A, Hazekamp M. Interact Cardiovasc Thorac Surg. 2021 Feb 6:ivab004. doi: 10.1093/icvts/ivab004. Online ahead of print. PMID: 33547474   Take Home Points: Hybrid procedure facilitates both Aortic valve/LVOT and LV growth regardless of the level of hypoplasia. Long-term follow up is required to see the benefit of pursuing the biventricular physiology in oppose to single ventricle physiology.   Commentary from Dr. Yasu Kotani (Okayama, Japan), section editor of Congenital Heart Surgery Journal Watch:   Summary: A total of 33 infants with borderline LV (Borderline LV: N=19, Severe AS/LVOTO: N=14) underwent hybrid procedure at median age of 11days at 3.5kg. During the interstage period of 62 days, 7 catheter-based and 7 surgical-based reintervention were performed. Patients with borderline LV had a significant increase in both LVEDVi and AoV/LVOT. Similarly, patients with small AoV/LVOT achieved adequate growth of both LVEDVi and AoV/LVOT. Twenty-seven patients had a biventricular repair with 16 patients had aortic arch repair, ventricular septal defect closure, and relief of subaortic stenosis, 5 patients had Ross-Konno procedure, 5 patients had Yasui procedure, and 1 patient had AVSD and aortic arch repair. Twenty-three (85%) patients are alive at median follow up of 3.3 years. There were 22 reinterventions and 15 reoperations.   Significance: Hybrid procedure has been developed as the first palliation of hypoplastic left heart syndrome but it is well known that this procedure can be fit to the patients with borderline LV in the aim for LV growth. This paper showed that 90% of patients with borderline LV achieved biventricular repair. More interestingly, it demonstrated that hybrid procedure can facilitate multi-level hypoplasia (AoV, LVOT, and LV) regardless of initial anatomy (either small AoV/LVOT or small LV volume).   Commentary: Previous papers reported that hybrid procedure facilitated the LV growth and subsequently achieved biventricular repair which is no doubt. This paper from the one of the leading centers in Netherland also showed a high rate (90%) of the achievement of biventricular repair. They are quite aggressive that 5 out of 27 patients had Ross-Konno procedure to achieve biventricular repair. It is important to emphasize that 15 % died and 25% required reintervention after biventricular repair within relatively short-term period of 3 years.   This result makes us consider that the data should be carefully interpreted. Firstly, the paper did not describe the detail of the atrial communication which is very important. An exact size and how restrictive (pressure gradient between LA and RA) to adjust ASD are crucial to let the blood go into the LV, hence LV are under the circumstance to grow and this may alter the degree of the growth. Secondly, they showed a significant increase in AoV, LVOT, and LV volume, however, it seems some patients still fell from the criteria of biventricular size by looking at the figure. Although they describe the criteria, the final decision to go for the biventricular repair might be taken intraoperatively by surgeon, hence the selection bias may be existing. Finally, this study did not have the control group that single ventricle repair being performed. Taken together, long-term follow up is necessary to see the advantage of biventricular repair, including survival, freedom from reoperation, and functional status compared to single ventricle repair.   

Management of Complex Left Ventricular Outflow Tract Obstruction: A Comparison of Konno and Modified Konno Techniques Mahwish Haider, Laura Carlson, Hua Liu, Christopher Baird, John E. Mayer, Meena Nathan Pediatr Cardiol. 2021 Feb 8 : 1–14. doi: 10.1007/s00246-020-02522-9 [Epub ahead of print] PMCID: PMC7869422 ArticlePubReaderPDF–989K   Take Home Messages In patients who undergo Modified Konno operation for LVOT obstruction, there is a significantly higher rate of LVOT reintervention compared to Konno operation.Transplant free survival is statistically similar for Konno and modified Konno operations.The use of the Konno operation is associated with patients who have multiple left sided lesions.   Commentary from Dr. Luis Quinonez (Boston MA USA), section editor of Congenital Heart Surgery Journal Watch:   Summary Purpose: To compare outcomes of the Konno procedure to the Modified Konno procedure   Population: 122 patients, single institution, 1990 to 2014   Intervention: Konno (n=51) and modified Konno operations (n=71)   Design: Retrospective review   Primary outcome: LVOT re-intervention   Secondary outcomes: Overall re-interventions; transplant-free survival; composite of re-interventions and transplant-free survival; hospital mortality and major adverse events; hospital length of stay   Results: Median age, Konno vs. modified Konno: 8.2 years vs 3.9 years (p=0.03) Median Follow-up: 8 years Patients with multiple left sided lesions more likely to have Konno (p=0.017) Hospital outcomes (Konno vs. modified Konno): No statistical difference: mortality (7.8% vs. 4.2%), major adverse events, permanent pacemaker (11.8% vs. 9.9%) Multivariate analysis: Konno had longer LOS Patients with multiple left sided lesions: more complications (48%), more surgical reinterventions (22.9%); longer ICU and hospital LOS Post-Discharge outcomes, Konno vs. modified Konno: LVOT reintervention at 10 years: 11% vs. 47% (p=0.002) Multivariate analysis: Modified Konno risk factor for LVOT intervention Overall reintervention at 10 years: 44% vs. 60% (p=0.114) Transplant free survival at 10 years: 92% vs. 85% (p=0.188) Multivariate analysis: Konno or modified Konno are not risk factors for survival. Commentary: This paper is a large, single institution experiences comparing outcomes of Konno against modified Konno procedures with long-term follow-up. The results are mostly intuitive, in that Konno patients were operated at an older age; they had less LVOT interventions; and patients with multiple left sided lesions fare worse. Despite modified Konno patients having more LVOT interventions, the overall rate on interventions was similar in both groups over time. Both groups would have reinterventions on the RVPA conduit, but patients who had Konno procedures would have more MV interventions, as they were more likely to have multiple left sided lesions. Being retrospective, underlying surgical selection biases are reflected: modified Konno in younger patients to try to preserve the aortic valve; and Konno in patients with multiple left sided lesions.   The study also demonstrates a significant operative mortality for the groups, as well as need for permanent pacemaker for both procedures. Although the overall reintervention rate and transplant free survival was not statistically different between the two procedures, the absolute numbers favour the use of the Konno, which is worth noting.   Patients with LVOT obstruction continue to remain a surgical challenge so these data are worth reviewing. The literature review provided is helpful.