Clinical presentation and surgical outcomes in patients with Shone's complex: a systematic review

OBJECTIVE

Shone's complex comprises of a combination of congenital cardiac anomalies causing obstructions in the left ventricle's inflow and outflow tracts. This systematic review aims to evaluate the clinical features and surgical outcomes of Shone's complex.

METHODS

An electronic literature search of PubMed and Scopus was performed to identify relevant studies related to the presentation, management, and outcomes of Shone's complex. Two reviewers independently performed selection. Data on study characteristics, participant demographics, interventions, outcomes, and follow-up durations were extracted and analyzed.

RESULTS

A total of 691 papers were identified, with 18 studies included in the final analysis. The majority of the studies (n = 12) focused on the pediatric age group. The most common clinical presentations were coarctation of the aorta (n = 17) and mitral stenosis (n = 12). Surgical interventions often involved staged approaches, prioritizing outflow before inflow obstructions. Mitral valve repair was preferred over replacement due to better long-term outcomes (n = 8). Biventricular repair was recommended due to improved postoperative outcomes, but often needed reoperations. Reoperations were common, primarily due to recurrent coarctation (n = 10), subaortic stenosis (n = 8), and mitral valve dysfunction (n = 7). Pulmonary hypertension (n = 10) and arrhythmias (n = 11) were significant complications. Most patients were in modified Ross/NYHA functional class 1 on follow-up. Mortality rates ranged from 4 to 28%, with better outcomes associated with early and strategic surgical interventions.

CONCLUSION

Early diagnosis and biventricular repair were associated with better outcomes while transplantation was often an eventuality. Standardized diagnostic criteria, long-term follow-up, and consensus guidelines are needed to improve the management of this congenital heart disease.

Surgical Considerations in Shone Complex

Shone complex is defined by 4 anomalies: parachute mitral valve, supravalvar mitral ring, subaortic stenosis, and coarctation of the aorta. Establishing a clear definition is one of the principal challenges in the study of Shone complex as not all patients have all lesions. The essential feature of Shone complex is multilevel left-sided obstruction involving both the left ventricular inflow and outflow. This anatomic variability is reflected in the clinical presentation as signs of left ventricular inflow obstruction are often masked by outflow obstruction and the multilevel nature of the condition is thus underappreciated. Surgical treatment is often stepwise addressing the outflow obstruction first. In this review, geared to the pediatric cardiac anesthesiologist, we review the pathophysiology, diagnosis, treatment, and outcomes of Shone complex.

Mitral Valve Intervention, Pulmonary Hypertension, and Survival in 219 Shone's Syndrome Patients

BACKGROUND

Relationships between pulmonary hypertension (PHTN), mitral valve intervention (MVI), and death among patients with Shone's syndrome (SS) are unclear. Our recent data suggested temporal progression of MV disease and early survival benefit with MVI at initial operation. In this expanded cohort, we characterized trajectory and impact of PHTN on survival, and its relationship to MVI(s).

METHODS

Record review of 219 SS patients undergoing operation at our quaternary center between 1956-2022, 111 of whom were pediatric (< age 18 yrs.). Patients were determined to have PHTN using a time-defined hierarchical algorithm consisting of cardiac catheterization data, echocardiographic parameters, pulmonary vasodilator therapy, and record-verified PHTN diagnosis. Analysis includes risk-adjusted predicted survival and freedom from PHTN curves stratified by MVI timing.

RESULTS

Among 219 patients, 92 (43%) had mitral valve stenosis on presentation, with mean gradients of 3.5 (IQR 4.7). Sixty patients had at least one MVI (15 (6%) and 8 (3%) had 3 or more). Median follow-up was 19 years (IQR 29) with 18 (8%) deaths. Ninety-three (42%) patients developed PHTN, with 50% and 25% freedom from PHTN at 37 and 51 years from presentation. PHTN was strongly associated with death (p <0.001). In unadjusted analyses, MVI, even if successive, delayed the onset of PHTN at 10 years and improved survival (p<0.001). However, this protective effect was lost after risk-adjustment.

CONCLUSIONS

PHTN development in SS is progressive and mirrors the survival curve, suggesting it is a major mortality risk-factor. Salutary effects of early and/or successive MVI are reduced after risk-adjustment.

Characterizing the anatomic spectrum, surgical treatment, and long-term clinical outcomes for patients with Shone's syndrome

OBJECTIVE

Shone's syndrome (SS) has a varied anatomic spectrum without consensus on need and timing for mitral valve intervention (MVI). We sought to (1) characterize the anatomic spectrum and treatment pathways; (2) describe long-term outcomes and their determinants; and (3) define the impact of MVI timing on survival.

METHODS

In total, 121 patients with SS who underwent operation at Cleveland Clinic between 1956 and 2021 were reviewed. Multivariable parametric hazard analyses including time-varying covariables, and modulated renewal to account for repeated events, were performed. End points included time-related survival and reintervention.

RESULTS

Median follow-up was 9.9 years. Mitral stenosis (MS) (98%), coarctation (80%), and aortic stenosis (70%) predominated. The most common combination was MS + aortic stenosis + coarctation (26%). Median initial mean mitral and aortic gradients were 3.6 (15th/85th percentiles: 2.0/6.8) and 9.0 (2.1/46) mm Hg, respectively. Median initial surgery age was 0.041 (0.011/3.2) years. Initial surgeries included coarctation repair (43%), arch repair (18%), and staged biventricular repair (18%). Overall survival was 92% at 20 years. Freedom from reoperation was 66% and 24% at 1 and 20 years. Patients with no MVI or initial MVI (N = 7) tended to be associated with better early survival compared with those with MVI at subsequent operation (N = 29) (P = .06). Risk factors for early reintervention included initial Norwood operation, with younger age and arch hypoplasia increasing later reintervention.

CONCLUSIONS

Despite excellent long-term survival, reoperation in SS is frequent and occurs most commonly on left ventricular outflow tract and mitral valve. Although MS is present in most, few require MVI. Delaying MVI may compromise early survival.

Evaluation of midterm outcomes after Shone's complex surgery: Analysis of reoperation and mortality risk factors

OBJECTIVE

The midterm results of patients who underwent biventricular repair surgery for Shone's complex were examined, and mortality and reoperation risk factors were evaluated.

METHODS

This retrospective study included 34 patients with Shone's complex who underwent mitral valve (MV) surgery between 2005 and 2020.

RESULTS

A total of 19 patients (56%) had coarctation, 10 (29%) patients had subaortic stenosis, 9 (26.5%) patients had a hypoplastic aortic arch (AA), and 9 (26.5%) patients had aortic valve (AV) stenosis. Twenty-four (70.6%) patients had bileaflet AV. Associated left-sided in-flow stenotic lesions included parachute MV in 19 (56%) patients and supramitral ring in 18 (53%) patients. The estimated freedom from reoperation rate on the 6th month, 1 year and 2 years after surgery was 84.4%, 79.5%, and 71.5%, respectively. The overall mortality rate was 20.6% (seven patients) with a median follow-up of 10 months (0-41). The estimated survival rate on the 6th month, 1 year, and 3 years after surgery was 83.8%, 79.4%, and 79.4 respectively. Bicuspid aortic valve (p = .017) (HR (95% CI) = 0.130 (0.025-0.695) and hammock mitral valve (p = .038) (HR (95% CI) = 11,008 (1,146->100) were associated with mortality.

CONCLUSION

The presence of a bicuspid aortic valve hammock mitral valve might have an effect on negative effect on the outcome.

An unusual case of Shone's complex in an adult depicted on computed tomography angiography

We present a case of a 22-year-old male with dyspnea on exertion where computed tomography revealed complete Shone's complex. This case highlights the complementary role of computed tomography in the anatomical evaluation of patients with complex heart diseases.

Replacement of the Mitral Valve Under One Year of Age: Size Matters

Surgical management of mitral valve disease in neonates and infants is challenging. When repair is no longer feasible, replacement may become inevitable, but should only be considered as an option of last resort due to the remarkably high rate of associated morbidity and mortality. Mechanical valves are the preferred choice in large annuli, while stented conduits seem promising in smaller ones. In patients with a preoperative mitral valve annulus equal or larger than 15-16 mm, an intra-annular placement of the smallest mechanical valve available should be attempted. In patients with smaller annuli, the placement of a stented valved conduit seems to display a lower mortality risk. Supra-annular implantation of prostheses should be reserved for exceptional cases and to those familiar with this technique because of the high rate of associated complications.

Outcomes of biventricular repair for shone's complex

BACKGROUND

Shone's complex is a rare lesion affecting the mitral valve (MV) and left ventricular outflow tract (LVOT). The objective of this study is to report the outcomes after Shone's complex repair, the growth of mitral and aortic valve and LVOT, and long-term survival.

METHODS

This retrospective study included all patients diagnosed with Shone's complex, who underwent biventricular repair. Data including patients' characteristics, type of the MV lesion and the associated lesions were collected. Patients were followed up regularly with echocardiography, and the changes in mitral and aortic valve z-score and LVOT z-score were recorded.

RESULTS

Thirty-seven patients were included in the study, the median age was 3.4 months, and 11 patients (30.6%) had pulmonary hypertension. The main procedure performed during the first surgical intervention was coarctation repair in 26 patients (70%). Twelve patients had MV repair, and five had MV replacement. Operative mortality occurred in 1 patient (2.7%), median follow up was 52 (25-75th percentile: 22-84) months. Survival at 1, 5, and 10 years was 94.4%, 90%, and 76.9%, respectively. Reoperation was required in 13 patients, mainly for LVOT repair (n = 8). Reoperation was significantly associated with associated aortic valve lesion (p = .044). The growth of the MV z-score was 0.35 per year; p < .001, aortic valve z-score 0.086 per year; p = 0.422, and the LVOT z-score was 0.53 per year; p = .01.

CONCLUSION

Biventricular repair of Shone's complex has good outcomes. Reoperation is frequently encountered, especially with low aortic valve z-score. The MV and LVOT have significant growth following Shone's complex repair.