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Wang Z, Ma K, Zhu Y, Li Z, Li S. Individualised surgical treatment strategy for subaortic stenosis. Cardiol Young 2024:1-8. [PMID: 38584316 DOI: 10.1017/s1047951124000830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
OBJECTIVES The clinical data of patients with subaortic stenosis who underwent surgical treatment in our centre in the past 12 years were reviewed. The short-term and long-term clinical outcomes were analyzed, and the long-term outcomes of different surgical methods for subaortic stenosis were compared to determine the optimal surgical treatment strategy for subaortic stenosis. METHODS From December 2010 to December 2022, 90 patients undergoing surgical treatment for subaortic stenosis in our hospital were enrolled. There were 55 males and 35 females with a median age of 72 (46,132) months and an average surgical weight of (21.35 ± 15.84) kg. According to the operation method, 90 patients were divided into group A (50 patients with simple subaortic membrane resection) and group B (40 patients with subaortic membrane and muscle resection or modified Konno procedure). RESULTS There were three early deaths (3.33%). One late death occurred in group B. There was no significant difference in long-term survival rate between the two groups (p = 0.904). The preoperative left ventricular outflow tract pressure gradient in group B was (91.56 ± 36.98) mm Hg, which was higher than that in group A(51.13 ± 36.04)mm Hg(p < 0.001). There was no significant difference in immediate postoperative left ventricular outflow tract pressure gradient between group B [(5.44 ± 8.43) mm Hg] and group A [(7.82 ± 13.44) mm Hg] (p = 0.343). In the long-term follow-up, left ventricular outflow tract pressure gradient in group B was (5.86 ± 9.53) mm Hg, which was not statistically significant compared with group A (8.83 ± 14.52) mm Hg (p = 0.294). Eleven patients with moderate or greater aortic regurgitation (group A/group B: 3/8) underwent simultaneous aortic valvuloplasty. In group B, moderate or greater aortic regurgitation was significantly improved immediately after operation (p = 0.013) and was not significantly aggravated in long-term follow-up (p = 0.083), and there was no significant improvement in group A after operation and long-term follow-up. CONCLUSIONS According to the different anatomical lesions of left ventricular outflow tract, the individualised surgical treatment strategy for patients with subaortic stenosis can achieve good long-term outcomes. The long-term survival rate and freedom from reoperation due to late left ventricular outflow tract obstruction after simple subaortic membrane resection and extended left ventricular outflow tract resection are comparable. For patients with moderate or greater aortic regurgitation before extended left ventricular outflow tract resection, simultaneous aortic valvuloplasty is beneficial to improve postoperative aortic valve function.
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Affiliation(s)
- Zhangwei Wang
- Department of Cardiovascular Surgery, Chinese Academy of Medical Sciences and Peking Union Medical College, National Center for Cardiovascular Diseases, Fuwai Hospital, Beijing, China
| | - Kai Ma
- Department of Cardiovascular Surgery, Chinese Academy of Medical Sciences and Peking Union Medical College, National Center for Cardiovascular Diseases, Fuwai Hospital, Beijing, China
| | - Yaobin Zhu
- Department of Cardiac Surgery, Beijing Children's Hospital, Capital Medical University, National Children's Medical Center, Beijing, China
| | - Zhiqiang Li
- Department of Cardiac Surgery, Beijing Children's Hospital, Capital Medical University, National Children's Medical Center, Beijing, China
| | - Shoujun Li
- Department of Cardiovascular Surgery, Chinese Academy of Medical Sciences and Peking Union Medical College, National Center for Cardiovascular Diseases, Fuwai Hospital, Beijing, China
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Schlein J, Wollmann F, Kaider A, Wiedemann D, Gabriel H, Hornykewycz S, Base E, Michel-Behnke I, Laufer G, Zimpfer D. Long-term outcomes after surgical repair of subvalvular aortic stenosis in pediatric patients. Front Cardiovasc Med 2022; 9:1033312. [DOI: 10.3389/fcvm.2022.1033312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/11/2022] [Indexed: 12/03/2022] Open
Abstract
ObjectivesSubvalvular aortic stenosis (SAS) can occur as discrete or tunnel-like obstruction of the left ventricular outflow tract and as progressive disease often leads to aortic valve regurgitation. We report our 30-year single-center experience after surgical repair of SAS.MethodsA retrospective chart review of all patients aged < 18 years, who underwent surgical repair of SAS from May 1985 to April 2020, was conducted. Mortality was cross-checked with the national health insurance database (93.8% complete mortality follow-up in April 2020). Survival and competing risks analysis were used to analyze the primary endpoints survival and incidence of reoperations.ResultsFrom May 1985 until April 2020 103 patients (median age 5.5 years) underwent surgical repair of SAS. Survival was 90.8% at 10 years and 88.7% at 20 and 30 years. Age < 1 year at time of surgery, Shone’s complex, mitral stenosis and concomitant mitral valve surgery were associated with mortality. The cumulative incidence of reoperation for SAS was 21.6% at 10 years, 28.2% at 20 and 30 years. The incidence of reoperation for SAS did not differ between the myectomy, membrane resection and combined myectomy and membrane resection groups. The cumulative incidence of reoperation on the aortic valve was 13.5% at 20 years.ConclusionRecurrence rate of SAS is not to be neglected, though surgical repair of subaortic stenosis has good long-term results. Patients who needed a combined membrane resection and septal myectomy are not more prone to recurrence than patients who underwent solitaire myectomy or membrane resection.
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Managing uncertainty in decision-making of common congenital cardiac defects. Cardiol Young 2022; 32:1705-1717. [PMID: 36300500 DOI: 10.1017/s1047951122003316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Decision-making in congenital cardiac care, although sometimes appearing simple, may prove challenging due to lack of data, uncertainty about outcomes, underlying heuristics, and potential biases in how we reach decisions. We report on the decision-making complexities and uncertainty in management of five commonly encountered congenital cardiac problems: indications for and timing of treatment of subaortic stenosis, closure or observation of small ventricular septal defects, management of new-onset aortic regurgitation in ventricular septal defect, management of anomalous aortic origin of a coronary artery in an asymptomatic patient, and indications for operating on a single anomalously draining pulmonary vein. The strategy underpinning each lesion and the indications for and against intervention are outlined. Areas of uncertainty are clearly delineated. Even in the presence of "simple" congenital cardiac lesions, uncertainty exists in decision-making. Awareness and acceptance of uncertainty is first required to facilitate efforts at mitigation. Strategies to circumvent uncertainty in these scenarios include greater availability of evidence-based medicine, larger datasets, standardised clinical assessment and management protocols, and potentially the incorporation of artificial intelligence into the decision-making process.
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Shar JA, Keswani SG, Grande-Allen KJ, Sucosky P. Significance of aortoseptal angle anomalies to left ventricular hemodynamics and subaortic stenosis: A numerical study. Comput Biol Med 2022; 146:105613. [PMID: 35751200 PMCID: PMC10570849 DOI: 10.1016/j.compbiomed.2022.105613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/02/2022] [Accepted: 05/10/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE Discrete subaortic stenosis (DSS) is an obstructive cardiac disease caused by a membranous lesion in the left ventricular (LV) outflow tract (LVOT). Although its etiology is unknown, the higher prevalence of DSS in LVOT anatomies featuring a steep aortoseptal angle (AoSA) suggests a potential role for hemodynamics. Therefore, the objective of this study was to quantify the impact of AoSA steepening on the LV three-dimensional (3D) hemodynamic stress environment. METHODS A 3D LV model reconstructed from cardiac cine-magnetic resonance imaging was connected to four LVOT geometrical variations spanning the clinical AoSA range (115°-160°). LV hemodynamic stresses were characterized in terms of cycle-averaged pressure, temporal shear magnitude (TSM), and oscillatory shear index. The wall shear stress (WSS) topological skeleton was further analyzed by computing the scaled divergence of the WSS vector field. RESULTS AoSA steepening caused an increasingly perturbed subaortic flow marked by LVOT flow skewness and complex 3D secondary flow patterns. These disturbances generated WSS overloads (>45% increase in TSM vs. 160° model) on the inferior LVOT wall, and increased WSS contraction (>66% decrease in WSS divergence vs. 160° model) in regions prone to DSS membrane formation. CONCLUSIONS AoSA steepening generated substantial hemodynamic stress abnormalities in LVOT regions prone to DSS formation. Further studies are needed to assess the possible impact of such mechanical abnormalities on the tissue and cellular responses.
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Affiliation(s)
- Jason A Shar
- Department of Mechanical Engineering, Kennesaw State University, 840 Polytechnic Lane, Marietta, GA, 30060, USA.
| | - Sundeep G Keswani
- Division of Pediatric Surgery, Texas Children's Hospital, Department of Surgery, Baylor College of Medicine, USA.
| | | | - Philippe Sucosky
- Department of Mechanical Engineering, Kennesaw State University, 840 Polytechnic Lane, Marietta, GA, 30060, USA.
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Abstract
OBJECTIVE The aim of this study is to evaluate clinical and surgical outcomes of children with subaortic stenosis, to determine the risk factors for surgery and reoperation and to compare isolated subaortic stenosis and those concomitant with CHDs. METHODS The study involved 80 children with subaortic stenosis. The patients were first classified as isolated and CHD group, and the isolated group was further classified as membranous/fibromuscular group. The initial, pre-operative, post-operative and the most recent echocardiographic data, demographic properties and follow-up results of the groups were analysed and compared. The correlation of echocardiographic parameters with surgery and reoperation was evaluated. RESULTS There was a significant male predominance in all groups. The frequency of the membranous type was higher than the fibromuscular type in the whole and the CHD group. The median time to the first operation was 4.6 years. Thirty-five (43.7%) patients underwent surgery, 5 of 35 (14%) patients required reoperation. The rate of surgery was similar between groups, but reoperation was significantly higher in the isolated group. The gradient was the most important factor for surgery and reoperation in both groups. In the isolated group besides gradient, mitral-aortic separation was the only echocardiographic parameter correlated with surgery and reoperation. CONCLUSION Reoperation is higher in isolated subaortic stenosis but similar in membranous and fibromuscular types. Early surgery may be beneficial in preventing aortic insufficiency but does not affect the rate of reoperation. Higher initial gradients are associated with adverse outcomes, recurrence and reoperation.
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De Wolf R, François K, Bové T, Coomans I, De Groote K, De Wilde H, Panzer J, Vandekerckhove K, De Wolf D. Paediatric subaortic stenosis: long-term outcome and risk factors for reoperation. Interact Cardiovasc Thorac Surg 2021; 33:588-596. [PMID: 34002231 DOI: 10.1093/icvts/ivab121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 01/20/2023] Open
Abstract
OBJECTIVES Surgical repair of subaortic stenosis (SAS) is associated with a substantial reoperation risk. We aimed to identify risk factors for reintervention in relation to discrete and tunnel-type SAS morphology. METHODS Single-centre retrospective study of paediatric SAS diagnosed between 1992 and 2017. Multivariable Cox regression analysis was performed to identify reintervention risk factors. RESULTS Eighty-five children [median age 2.5 (0.7-6.5) years at diagnosis] with a median follow-up of 10.1 (5.5-16.4) years were included. Surgery was executed in 83% (n = 71). Freedom from reoperation was 88 ± 5% at 5 years and 82 ± 6% at 10 years for discrete SAS, compared to, respectively, 33 ± 16% and 17 ± 14% for tunnel-type SAS (log-rank P < 0.001). Independent risk factors for reintervention were a postoperative gradient >20 mmHg [hazard ratio (HR) 6.56, 95% confidence interval (CI) 1.41-24.1; P = 0.005], tunnel-type SAS (HR 7.46, 95% CI 2.48-22.49; P < 0.001), aortic annulus z-score <-2 (HR 11.07, 95% CI 3.03-40.47; P < 0.001) and age at intervention <2 years (HR 3.24, 95% CI 1.09-9.86; P = 0.035). Addition of septal myectomy at initial intervention was not associated with lesser reintervention. Fourteen children with a lower left ventricular outflow tract (LVOT) gradient (P < 0.001) and older age at diagnosis (P = 0.024) were followed expectatively. CONCLUSIONS Children with SAS remain at risk for reintervention, despite initially effective LVOT relief. Regardless of SAS morphology, age <2 years at first intervention, a postoperative gradient >20 mmHg and presence of a hypoplastic aortic annulus are independent risk factors for reintervention. More extensive LVOT surgery might be considered at an earlier stage in these children. SAS presenting in older children with a low LVOT gradient at diagnosis shows little progression, justifying an expectative approach.
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Affiliation(s)
- Rik De Wolf
- Faculty of Medicine and Pharmacy, Free University of Brussels, Brussels, Belgium
| | - Katrien François
- Department of Cardiac Surgery, Ghent University Hospital, Ghent, Belgium
| | - Thierry Bové
- Department of Cardiac Surgery, Ghent University Hospital, Ghent, Belgium
| | - Ilse Coomans
- Department of Paediatric Cardiology, Ghent University Hospital, Ghent, Belgium
| | - Katya De Groote
- Department of Paediatric Cardiology, Ghent University Hospital, Ghent, Belgium
| | - Hans De Wilde
- Department of Paediatric Cardiology, Ghent University Hospital, Ghent, Belgium
| | - Joseph Panzer
- Department of Paediatric Cardiology, Ghent University Hospital, Ghent, Belgium
| | | | - Daniël De Wolf
- Department of Paediatric Cardiology, Ghent University Hospital, Ghent, Belgium.,Department of Paediatric Cardiology, University Hospital of Brussels, Brussels, Belgium
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Carlson L, Pickard S, Gauvreau K, Baird C, Geva T, del Nido P, Nathan M. Preoperative Factors That Predict Recurrence After Repair of Discrete Subaortic Stenosis. Ann Thorac Surg 2021; 111:1613-1619. [DOI: 10.1016/j.athoracsur.2020.05.140] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 05/08/2020] [Accepted: 05/18/2020] [Indexed: 11/28/2022]
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Tal N, Golender J, Rechtman Y, Tidhar D, Erez E. Long-Term Aortic Valve Function in Patients With or Without Surgical Treatment for Discrete Subaortic Stenosis. Pediatr Cardiol 2021; 42:324-330. [PMID: 33048184 DOI: 10.1007/s00246-020-02486-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 10/03/2020] [Indexed: 11/30/2022]
Abstract
The purpose of this study was to evaluate the long-term function of the aortic valve in patients with discrete subaortic stenosis (DSS), and its prognostic implications. 34 patients with the diagnosis of isolated DSS were treated at our pediatric heart center between 1992 and 2019. Demographic, echocardiographic and surgical data were analyzed. 26 patients had surgery to remove the subaortic membrane. The primary endpoint of this study was a change in the aortic valve function, secondary outcomes included functional class, aortic valve replacement, and reoperation due to recurrence of DSS. The mean post-operative follow-up time was 7.07 years (1-22.5). At the time of the most recent follow up, in the surgical group 11 patients (46%) had echocardiographic evidence of deterioration in their aortic valve insufficiency (AI) (p < 0.002). The deterioration was associated with a pre-operative left ventricular outflow tract (LVOT) gradient greater than 49 mmHg (p < 0.022). 8 patients with DSS were followed for a mean of 12.9 years (6.8-21.3), without meeting the criteria for surgical intervention, none showed any change in the aortic valve function during follow-up time. DSS resection may not prevent worsening of aortic valve insufficiency over time. Patients with stable AI and low LVOT gradient may not require surgery. Given these findings, it may be appropriate to carefully follow patients with new onset AI and low LVOT gradient, delaying surgical intervention.
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Affiliation(s)
- Nitzan Tal
- Department of Cardiothoracic Surgery, Hadassah Medical Center, Hebrew University School of Medicine, Jerusalem, Israel
| | - Julius Golender
- Department of Pediatric Cardiology, Hadassah Medical Center, Hebrew University School of Medicine, Jerusalem, Israel
| | - Yifat Rechtman
- Department of Cardiothoracic Surgery, Hadassah Medical Center, Hebrew University School of Medicine, Jerusalem, Israel
| | - Doreen Tidhar
- Department of Cardiothoracic Surgery, Hadassah Medical Center, Hebrew University School of Medicine, Jerusalem, Israel
| | - Eldad Erez
- Department of Cardiothoracic Surgery, Hadassah Medical Center, Hebrew University School of Medicine, Jerusalem, Israel.
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Shar JA, Keswani SG, Grande-Allen KJ, Sucosky P. Computational Assessment of Valvular Dysfunction in Discrete Subaortic Stenosis: A Parametric Study. Cardiovasc Eng Technol 2021; 12:559-575. [PMID: 33432514 DOI: 10.1007/s13239-020-00513-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 12/22/2020] [Indexed: 01/16/2023]
Abstract
PURPOSE Discrete subaortic stenosis (DSS) is a left-ventricular outflow tract (LVOT) obstruction caused by a membranous lesion. DSS is associated with steep aortoseptal angles (AoSAs) and is a risk factor for aortic regurgitation (AR). However, the etiology of AR secondary to DSS remains unknown. This study aimed at quantifying computationally the impact of AoSA steepening and DSS on aortic valve (AV) hemodynamics and AR. METHODS An LV geometry reconstructed from cine-MRI data was connected to an AV geometry to generate a unified 2D LV-AV model. Six geometrical variants were considered: unobstructed (CTRL) and DSS-obstructed LVOT (DSS), each reflecting three AoSA variations (110°, 120°, 130°). Fluid-structure interaction simulations were run to compute LVOT flow, AV leaflet dynamics, and regurgitant fraction (RF). RESULTS AoSA steepening and DSS generated vortex dynamics alterations and stenotic flow conditions. While the CTRL-110° model generated the highest degree of leaflet opening asymmetry, DSS preferentially altered superior leaflet kinematics, and caused leaflet-dependent alterations in systolic fluttering. LVOT steepening and DSS subjected the leaflets to increasing WSS overloads (up to 94% increase in temporal shear magnitude), while DSS also increased WSS bidirectionality on the inferior leaflet belly (+ 0.30-point in oscillatory shear index). Although AoSA steepening and DSS increased diastolic transvalvular backflow, regurgitant fractions (RF < 7%) remained below the threshold defining clinical mild AR. CONCLUSIONS The mechanical interactions between AV leaflets and LVOT steepening/DSS hemodynamic derangements do not cause AR. However, the leaflet WSS abnormalities predicted in those anatomies provide new support to a mechanobiological etiology of AR secondary to DSS.
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Affiliation(s)
- Jason A Shar
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, USA
| | - Sundeep G Keswani
- Division of Pediatric Surgery, Department of Surgery, Texas Children's Hospital, Baylor College of Medicine, Houston, USA
| | | | - Philippe Sucosky
- Department of Mechanical Engineering, Kennesaw State University, 840 Polytechnic Lane, Marietta, GA, 30060, USA.
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Alqurashi GM, Almohanna RS, Ayoub KMK, Alkhuraiji AA, Almasoud NA, Alsubaie AR, Althubaiti AM, Al Sehly AA. Discrete Left Ventricle Outflow Tract Obstruction in Children: Incidence and Predictors of Recurrence. A Multi-Center Study. J Saudi Heart Assoc 2020; 32:358-364. [PMID: 33299776 PMCID: PMC7721451 DOI: 10.37616/2212-5043.1045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/27/2020] [Accepted: 07/02/2020] [Indexed: 11/21/2022] Open
Abstract
Objectives The purpose of this study is to measure the incidence of recurrence of discrete subaortic stenosis (DSS) after primary resection in two major cardiac centers in Saudi Arabia and to identify risk factors associated with recurrence. Methods Data on 234 patients who were diagnosed with DSS and underwent surgical resection between 1999 and 2018 were retrospectively reviewed. Patient demographics as well as echocardiographic, surgical, and pathological data were compared between patients with recurrence and non-recurrence. Results The overall recurrence incidence after primary resection was 44.87% (N = 105). Most patients were male (59%). The median age at the 1st operation was 60 months (range 3 months to 133 months). The presence of aortic stenosis at the time of diagnosis was significantly associated with recurrence (p-value = 0.002). The overall median peak gradient in which the primary resection was indicated is 60 mmHg (range 11 to 152 mmHg). The median peak gradient pre-operation and post-operation were significantly higher for the recurrence group (p-value=0.018 and p<0.001, respectively). We used univariate and multivariate analysis and controlled for the follow-up time, but there were no significant independent predictors of recurrence. Conclusion The recurrence rate of DSS after the primary resection is relatively high in this study. Further prospective studies are needed to draw a definite conclusion on risk factors for recurrence after primary resection.
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Affiliation(s)
- Gadah M Alqurashi
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Rema S Almohanna
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Kamal M K Ayoub
- King Abdulaziz Cardiac Center, National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Arwa A Alkhuraiji
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Najla A Almasoud
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Amjad R Alsubaie
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Alaa M Althubaiti
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia.,King Abdullah International Medical Research Centre, Jeddah, Saudi Arabia
| | - Abdullah A Al Sehly
- Heart Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
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Shar JA, Brown KN, Keswani SG, Grande-Allen J, Sucosky P. Impact of Aortoseptal Angle Abnormalities and Discrete Subaortic Stenosis on Left-Ventricular Outflow Tract Hemodynamics: Preliminary Computational Assessment. Front Bioeng Biotechnol 2020; 8:114. [PMID: 32175314 PMCID: PMC7056880 DOI: 10.3389/fbioe.2020.00114] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 02/04/2020] [Indexed: 12/27/2022] Open
Abstract
Discrete subaortic stenosis (DSS) is an obstruction of the left ventricular outflow tract (LVOT) due to the formation of a fibromuscular membrane upstream of the aortic valve. DSS is a major risk factor for aortic regurgitation (AR), which often persists after surgical resection of the membrane. While the etiology of DSS and secondary AR is largely unknown, the frequent association between DSS and aortoseptal angle (AoSA) abnormalities has supported the emergence of a mechanobiological pathway by which hemodynamic stress alterations on the septal wall could trigger a biological cascade leading to fibrosis and membrane formation. The resulting LVOT flow disturbances could activate the valve endothelium and contribute to AR. In an effort to assess this hypothetical mechano-etiology, this study aimed at isolating computationally the effects of AoSA abnormalities on septal wall shear stress (WSS), and the impact of DSS on LVOT hemodynamics. Two-dimensional computational fluid dynamics models featuring a normal AoSA (N-LV), a steep AoSA (S-LV), and a steep AoSA with a DSS lesion (DSS-LV) were designed to compute the flow in patient-specific left ventricles (LVs). Boundary conditions consisted of transient velocity profiles at the mitral inlet and LVOT outlet, and patient-specific LV wall motion. The deformation of the DSS lesion was computed using a two-way fluid-structure interaction modeling strategy. Turbulence was accounted for via implementation of the k-ω turbulence model. While the N-LV and S-LV models generated similar LVOT flow characteristics, the DSS-LV model resulted in an asymmetric LVOT jet-like structure, subaortic stenotic conditions (up to 2.4-fold increase in peak velocity, 45% reduction in effective jet diameter vs. N-LV/S-LV), increased vorticity (2.8-fold increase) and turbulence (5- and 3-order-of-magnitude increase in turbulent kinetic energy and Reynolds shear stress, respectively). The steep AoSA subjected the septal wall to a 23% and 69% overload in temporal shear magnitude and gradient, respectively, without any substantial change in oscillatory shear index. This study reveals the existence of WSS overloads on septal wall regions prone to DSS lesion formation in steep LVOTs, and the development of highly turbulent, stenotic and asymmetric flow in DSS LVOTs, which support a possible mechano etiology for DSS and secondary AR.
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Affiliation(s)
- Jason A. Shar
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH, United States
| | - Kathleen N. Brown
- Department of Bioengineering, Rice University, Houston, TX, United States
| | - Sundeep G. Keswani
- Division of Pediatric Surgery, Texas Children’s Hospital, Houston, TX, United States
- Department of Surgery, Baylor College of Medicine, Houston, TX, United States
| | - Jane Grande-Allen
- Department of Bioengineering, Rice University, Houston, TX, United States
| | - Philippe Sucosky
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH, United States
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Chen L, Schelegle A, Choi J, Amsterdam EA. What Lurks Beneath: A Subaortic Membrane. Am J Med 2019; 132:698-700. [PMID: 30857761 DOI: 10.1016/j.amjmed.2019.02.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 02/13/2019] [Accepted: 02/14/2019] [Indexed: 10/27/2022]
Affiliation(s)
- Lily Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California (Davis) Medical Center, Sacramento
| | - Aaron Schelegle
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California (Davis) Medical Center, Sacramento
| | - Jeong Choi
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California (Davis) Medical Center, Sacramento
| | - Ezra A Amsterdam
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California (Davis) Medical Center, Sacramento.
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Krieger EV, Stout KK, Grosse-Wortmann L. How to Image Congenital Left Heart Obstruction in Adults. Circ Cardiovasc Imaging 2019; 10:CIRCIMAGING.116.004271. [PMID: 28495822 DOI: 10.1161/circimaging.116.004271] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Eric V Krieger
- From the Seattle Adult Congenital Heart Service, University of Washington Medical Center (E.V.K., K.K.S.); Seattle Children's Hospital, Washington (E.V.K., K.K.S.); Department of Medicine, Division of Cardiology, University of Washington School of Medicine, Seattle (E.V.K., K.K.S.); and Labatt Family Heart Centre, Department of Pediatrics, and Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, ON, Canada (L.G.-W.)
| | - Karen K Stout
- From the Seattle Adult Congenital Heart Service, University of Washington Medical Center (E.V.K., K.K.S.); Seattle Children's Hospital, Washington (E.V.K., K.K.S.); Department of Medicine, Division of Cardiology, University of Washington School of Medicine, Seattle (E.V.K., K.K.S.); and Labatt Family Heart Centre, Department of Pediatrics, and Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, ON, Canada (L.G.-W.)
| | - Lars Grosse-Wortmann
- From the Seattle Adult Congenital Heart Service, University of Washington Medical Center (E.V.K., K.K.S.); Seattle Children's Hospital, Washington (E.V.K., K.K.S.); Department of Medicine, Division of Cardiology, University of Washington School of Medicine, Seattle (E.V.K., K.K.S.); and Labatt Family Heart Centre, Department of Pediatrics, and Department of Diagnostic Imaging, The Hospital for Sick Children, University of Toronto, ON, Canada (L.G.-W.).
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14
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Mazurek AA, Yu S, Lowery R, Ohye RG. Routine Septal Myectomy During Subaortic Stenosis Membrane Resection: Effect on Recurrence Rates. Pediatr Cardiol 2018; 39:1627-1634. [PMID: 30310939 DOI: 10.1007/s00246-018-1941-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/23/2018] [Indexed: 11/30/2022]
Abstract
Recurrence of subaortic stenosis (SubAS) is up to ~ 19% following resection. Historically, treatment has consisted of membrane resection alone. This study investigated the effect of routine septal myectomy in addition to membrane resection. A single-center retrospective review was performed in all patients < 18 years of age undergoing membrane resection with septal myectomy for SubAS from 2003 to 2013. Demographic, perioperative, and follow-up data were collected. Freedom from reoperation and risk factors for reoperation were determined. 107 patients (median age 4.8 years) were included. There was one in-hospital death, five patients (5%) requiring pacemaker, and no iatrogenic ventricular septal defects. Follow-up was 80% complete and median follow-up was 4.9 years (range 0.5-12 years). Fourteen (16%) subjects required reoperation. Freedom from reoperation was 98% at 1 year, 86% at 5 years, and 69% at 10 years (Fig. 1). There was no difference in decrease of peak gradient between subjects who did and did not require reoperation (- 47 vs. - 40 mmHg; p = 0.59). In univariate analysis, chromosomal anomaly (hazard ratio [HR] 5.0, p = 0.02), smaller body surface area (HR 0.1, p = 0.03), and younger age at surgery (HR 0.7, p = 0.01) were significantly associated with reoperation. The routine use of myectomy with membrane excision did not result in a lower rate of reoperation or higher rates of complications compared to historical controls. Younger age, smaller size, and chromosomal anomaly were associated with increased risk for reoperation. Patients with these risk factors may benefit from more intensive long-term follow-up.
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Affiliation(s)
- Alyssa A Mazurek
- Massachusetts General Hospital, 2 Leighton Street, Unit 310, Cambridge, MA, 02141, USA.
| | - Sunkyung Yu
- Michigan Medicine Congenital Heart Center, C.S. Mott Children's Hospital, Ann Arbor, MI, USA
| | - Ray Lowery
- Michigan Medicine Congenital Heart Center, C.S. Mott Children's Hospital, Ann Arbor, MI, USA
| | - Richard G Ohye
- Pediatric Cardiovascular Surgery, C.S. Mott Children's Hospital, Ann Arbor, MI, USA
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15
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Massé DD, Shar JA, Brown KN, Keswani SG, Grande-Allen KJ, Sucosky P. Discrete Subaortic Stenosis: Perspective Roadmap to a Complex Disease. Front Cardiovasc Med 2018; 5:122. [PMID: 30320123 PMCID: PMC6166095 DOI: 10.3389/fcvm.2018.00122] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 08/17/2018] [Indexed: 12/13/2022] Open
Abstract
Discrete subaortic stenosis (DSS) is a congenital heart disease that results in the formation of a fibro-membranous tissue, causing an increased pressure gradient in the left ventricular outflow tract (LVOT). While surgical resection of the membrane has shown some success in eliminating the obstruction, it poses significant risks associated with anesthesia, sternotomy, and heart bypass, and it remains associated with a high rate of recurrence. Although a genetic etiology had been initially proposed, the association between DSS and left ventricle (LV) geometrical abnormalities has provided more support to a hemodynamic etiology by which congenital or post-surgical LVOT geometric derangements could generate abnormal shear forces on the septal wall, triggering in turn a fibrotic response. Validating this hypothetical etiology and understanding the mechanobiological processes by which altered shear forces induce fibrosis in the LVOT are major knowledge gaps. This perspective paper describes the current state of knowledge of DSS, articulates the research needs to yield mechanistic insights into a significant pathologic process that is poorly understood, and proposes several strategies aimed at elucidating the potential mechanobiological synergies responsible for DSS pathogenesis. The proposed roadmap has the potential to improve DSS management by identifying early targets for prevention of the fibrotic lesion, and may also prove beneficial in other fibrotic cardiovascular diseases associated with altered flow.
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Affiliation(s)
- Danielle D Massé
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH, United States
| | - Jason A Shar
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH, United States
| | - Kathleen N Brown
- Department of Bioengineering, Rice University, Houston, TX, United States
| | - Sundeep G Keswani
- Division of Pediatric Surgery, Texas Children's Hospital, Houston, TX, United States.,Department of Surgery, Baylor College of Medicine, Houston, TX, United States
| | | | - Philippe Sucosky
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, OH, United States
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16
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Mukadam S, Gordon BM, Olson JT, Newcombe JB, Hasaniya NW, Razzouk AJ, Bailey LL. Subaortic Stenosis Resection in Children: Emphasis on Recurrence and the Fate of the Aortic Valve. World J Pediatr Congenit Heart Surg 2018; 9:522-528. [DOI: 10.1177/2150135118776931] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background: Recurrence after surgical resection of discrete subvalvar aortic stenosis in children often requires repeat operation. Risk factors for recurrence are poorly understood. We sought to determine potential risk factors for recurrence and postoperative comorbidities in the long term. Methods: Retrospective chart review was performed on all pediatric patients who underwent surgical resection of discrete subaortic stenosis at our institution. Demographics, perioperative findings, and clinical data were analyzed for predisposing factors. Results: From 1991 to 2015, a total of 104 patients underwent primary surgical resection of discrete subaortic stenosis. There were no postoperative deaths. Three (2.9%) patients required pacemaker implantation. Nine (8.4%) patients required repeat resection for recurrence of subaortic membrane over a median follow-up of 8.5 years (interquartile range: 5.9-13.5 years). Actuarial freedom from repeat resection was 100%, 94%, and 82% at one, five, and ten years, respectively. Repeat resection occurred more frequently in patients with genetic disease (37.5% vs 10.7%; P = .033) and preoperative mitral regurgitation (MR; 25% vs 1.2%; P < .001). Postoperative aortic insufficiency (AI) that was moderate or worse was associated with older age at the time of first resection (relative risk [RR]: 1.54, P < .05), moderate or severe preoperative AI (RR: 1.84, P = .002), and repeat resection of subaortic stenosis (RR: 1.90, P < .001). Conclusion: The majority of children who undergo surgical resection of subaortic stenosis will not experience recurrence in childhood and those who do require repeat resection may have a higher incidence of genetic disease and preoperative MR. Postoperative AI is associated with repeat resection, older age at the time of surgery, and degree of preoperative AI.
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Affiliation(s)
- Shireen Mukadam
- Division of General Pediatrics, Department of Pediatrics, Loma Linda University Hospital, Loma Linda, CA, USA
| | - Brent M. Gordon
- Division of Pediatric Cardiology, Department of Pediatrics, Loma Linda University Hospital, Loma Linda, CA, USA
| | - Jeffrey T. Olson
- Division of General Pediatrics, Department of Pediatrics, Loma Linda University Hospital, Loma Linda, CA, USA
- Department of Medicine, Loma Linda University Hospital, Loma Linda, CA, USA
| | - Jennifer B. Newcombe
- Department of Cardiovascular and Thoracic Surgery, Loma Linda University Hospital, Loma Linda, CA, USA
| | - Nahidh W. Hasaniya
- Department of Cardiovascular and Thoracic Surgery, Loma Linda University Hospital, Loma Linda, CA, USA
| | - Anees J. Razzouk
- Department of Cardiovascular and Thoracic Surgery, Loma Linda University Hospital, Loma Linda, CA, USA
| | - Leonard L. Bailey
- Department of Cardiovascular and Thoracic Surgery, Loma Linda University Hospital, Loma Linda, CA, USA
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17
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Abstract
PURPOSE OF REVIEW Distinction between discrete subvalvar aortic stenosis and other causes of left ventricular outflow obstruction has important implications for predicting natural history and guiding the timing and type of intervention. Imaging, primarily transthoracic echocardiography (TTE), plays a pivotal role in the diagnosis and management of adults with subvalvar aortic stenosis. RECENT FINDINGS Most systematic research on imaging of subvalvar aortic stenosis has focused on echocardiography. TTE, especially two-dimensional imaging with color and spectral Doppler, remains the main modality for delineation of the anatomic and hemodynamic features of subvalvar stenosis, associated anomalies and involvement of accessory mitral valve attachments to the subaortic septum or abnormally placed papillary muscles. Transesophageal echocardiography may provide more detailed definition of left ventricular outflow tract anatomy, including the presence and extension of the obstructive subaortic fibroelastic tissue onto the aortic or mitral valve, especially in patients with poor transthoracic windows. The clinical role for advanced imaging technologies, including three-dimensional echocardiography, cardiac magnetic resonance and computed tomography, is evolving but, largely because of the adequacy of established imaging with TTE, remains relatively limited. SUMMARY In the absence of other congenital heart defects or alternative indications (e.g. coronary angiography), TTE is usually adequate for the assessment of discrete subvalvar aortic stenosis in the adult. In specific clinical situations, supplemental imaging modalities can play an integral role in clinical decision making.
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18
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Abstract
DSS is generally an acquired and progressive condition. Subaortic stenosis often takes the form of a discrete crescentic fibromuscular ridge in the LVOT. DSS should be considered when an elevated aortic Doppler gradient is seen in the presence of normal aortic leaflet mobility. Surgery is considered when the peak instantaneous gradient is >50 to 60 mm Hg. DSS has a high rate of recurrence following surgical intervention.
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19
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Puncturing of lyophilized tissue engineered vascular matrices enhances the efficiency of their recellularization. Acta Biomater 2018; 71:474-485. [PMID: 29505888 DOI: 10.1016/j.actbio.2018.02.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/13/2018] [Accepted: 02/22/2018] [Indexed: 02/06/2023]
Abstract
Data on in vitro engineered "off the shelf" matrices support the concept of endogenous cellular repopulation driving the graft's remodeling via immune-mediated response. This seems important to further accelerate the cell reconstitution and may play a crucial role when mononuclear cells are used. Nevertheless, studies on decellularized xenogeneic grafts showed only limited host cell repopulation post-implantation. This study aims at a systematic comparison of reseeding methods (dripping, injection, bathing in a cell suspension and combined puncturing-dripping method) to define the most efficient technique enhancing recellularization of tissue engineered vascular matrices (patches, vessels, small diameter and standard size valves) prior implantation. The constructs were analyzed histologically, biochemically and biomechanically. Various preconditioning treatments (wet, lyophilized and air-dried) combined with reseeding methods demonstrated the highest cell loading efficiency, despite applied crimping and flow stress, of lyophilization followed by puncturing-dripping technique. This novel seeding method allows for an efficient, time-saving graft reseeding that can be used within a one-step cardiovascular clinical intervention. STATEMENT OF SIGNIFICANCE The concept of living tissue engineered, self-repairing, autologous cardiovascular replacements, was proposed alternatively to existing synthetic/xenogeneic prostheses. Recent studies in animal models demonstrate faster in vivo recellularization after grafts pre-seeding with cells prior implantation. Pre-seeded cells hold either, the ability to differentiate directionally or attract host cells, crucial for graft integration and remodeling. It is unclear, however, how efficient the pre-loading is and how well cells withstand the flow. The study presents a systematic overview of cell loading techniques of different cardiovascular constructs, tested under static and dynamic conditions. Comparison illustrates a significantly higher efficiency of cells loading in lyophilized tissues punctured before their standard seeding. This technique may beneficially accelerate remodeling of cardiovascular grafts in further in vivo studies.
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20
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Talwar S, Anand A, Gupta SK, Ramakrishnan S, Kothari SS, Saxena A, Juneja R, Choudhary SK, Airan B. Resection of subaortic membrane for discrete subaortic stenosis. J Card Surg 2017; 32:430-435. [DOI: 10.1111/jocs.13160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Sachin Talwar
- Cardiothoracic Center; All India Institute of Medical Sciences; New Delhi India
| | - Abhishek Anand
- Cardiothoracic Center; All India Institute of Medical Sciences; New Delhi India
| | - Saurabh Kumar Gupta
- Cardiothoracic Center; All India Institute of Medical Sciences; New Delhi India
| | | | | | - Anita Saxena
- Cardiothoracic Center; All India Institute of Medical Sciences; New Delhi India
| | - Rajnish Juneja
- Cardiothoracic Center; All India Institute of Medical Sciences; New Delhi India
| | | | - Balram Airan
- Cardiothoracic Center; All India Institute of Medical Sciences; New Delhi India
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