Supra-Annular Mitral Valve Replacement in Children

Mitral Valve Replacement in Infants and Children: Five-Year Outcomes of the HALO Clinical Trial

BACKGROUND

Repair is preferable for children with mitral valve disease, but mitral valve replacement (MVR) is occasionally necessary. This report presents the results of a multiinstitutional Investigational Device Exemption trial of the 15-mm St Jude (SJM) mechanical mitral valve (Abbott Structural Heart).

METHODS

From May 2015 to March 2017, 23 children aged 0.4 to 27.4 months (mean, 7.8 months; 85% <1 year) weighing 2.9 to 10.9 kg (mean, 5.5 kg) at 15 centers underwent MVR with a 15-mm SJM mechanical mitral valve (intraannular, 45%; supraannular, 55%). A total of 21 (91%) of the children had undergone previous cardiac operations. Follow-up until death, valve explantation, or 5 years postoperatively was 100% complete.

RESULTS

There were 6 deaths, all in the first 12 months; no death was valve related. Four patients required a pacemaker (2 supraannular, 2 intraannular). Three patients had thrombosis requiring valve explantation at 13, 21, and 35 days postoperatively. Two of these 3 patients were receiving low-molecular-weight heparin for anticoagulation, and the third had factor V Leiden deficiency. There were 5 nonfatal bleeding complications within 4 months of MVR (1-year freedom from bleeding, 71.0%). The 1- and 5-year freedom from death or valve explantation was 71.0%.

CONCLUSIONS

In small children with severe mitral valve disease requiring MVR, the 15-mm SJM mechanical mitral valve provides satisfactory hemodynamics. Mortality and complications in these patients are not trivial. Low-molecular-weight heparin likely should be avoided as primary anticoagulation. Eventual valve replacement is inevitable.

A CFD-FFT approach to hemoacoustics that enables degree of stenosis prediction from stethoscopic signals

In this paper, we identify a new (acoustic) frequency-stenosis relation whose frequencies lie within the recommended auscultation threshold of stethoscopy (< 120 Hz). We show that this relation can be used to extend the application of phonoangiography (quantifying the degree of stenosis from bruits) to widely accessible stethoscopes. The relation is successfully identified from an analysis restricted to the acoustic signature of the von Karman vortex street, which we automatically single out by means of a metric we propose that is based on an area-weighted average of the Q-criterion for the post-stenotic region. Specifically, we perform CFD simulations on internal flow geometries that represent stenotic blood vessels of different severities. We then extract their emitted acoustic signals using the Ffowcs Williams-Hawkings equation, which we subtract from a clean signal (stenosis free) at the same heart rate. Next, we transform this differential signal to the frequency domain and carefully classify its acoustic signatures per six (stenosis-)invariant flow phases of a cardiac cycle that are newly identified in this paper. We then automatically restrict our acoustic analysis to the sounds emitted by the von Karman vortex street (phase 4) by means of our Q-criterion-based metric. Our analysis of its acoustic signature reveals a strong linear relationship between the degree of stenosis and its dominant frequency, which differs considerably from the break frequency and the heart rate (known dominant frequencies in the literature). Applying our new relation to available stethoscopic data, we find that its predictions are consistent with clinical assessment. Our finding of this linear correlation is also unlike prevalent scaling laws in the literature, which feature a small exponent (i.e., low stenosis percentage sensitivity over much of the clinical range). They hence can only distinguish mild, moderate, and severe cases. Conversely, our linear law can identify variations in the degree of stenosis sensitively and accurately for the full clinical range, thus significantly improving the utility of the relevant scaling laws... Future research will investigate incorporating the vibroacoustic role of adjacent organs to expand the clinical applicability of our findings. Extending our approach to more complex 3D stenotic morphologies and including the vibroacoustic role of surrounding organs will be explored in future research to advance the clinical reach of our findings.

Mitral valve replacement in a 3.9-kg infant with fungal endocarditis: A case report

A three-month-old female infant with a structurally normal heart was diagnosed with fungal endocarditis of the mitral valve with cerebral embolism. After antifungal therapy and a valve-sparing operation with complete removal of the fungal vegetations, a relapse with complete destruction of the valve leaflets and severe mitral regurgitation with decompensated heart failure occurred three months later. A second operation with successful mitral valve replacement was performed. Non-compliance with the anticoagulant treatment with vitamin K antagonist led to thrombosis of the mitral valve prosthesis one year later, and the child died from acute pulmonary edema.

Mitral valve replacement in infants and younger children

Data on mitral valve replacement (MVR) in young children is still limited. Our objective was to evaluate MVR in children below 5 years and identify factors affecting the outcomes. This retrospective study included 29 patients who had MVR from 2002 to 2020. We grouped the patients into two groups according to their age: age ≤ 24 months (n = 18) and > 24 months (n = 11). Primary cardiac diagnoses were Shone complex (n = 7; 24%), isolated congenital mitral valve abnormality (n = 11; 38%), and complete atrioventricular septal defect (n = 3; 10%). The median age was 19 month (25th–75th percentile: 11–32) and 59% were females (n = 17). The hemodynamic lesions were mitral regurgitation in 66%, mitral stenosis in 10%, and combined mitral stenosis and regurgitation in 24% of the patients. St. Jude mitral valve was the most common valve implanted (n = 19, 66%), followed by CarboMedics in 21% of the patients (n = 6). The mitral valve was implanted in the supra-annular position in 6 cases (21%). Preoperative and operative data were comparable between both groups. There was no association between valve size and position with postoperative heart block (P > 0.99, for both). The median follow-up duration was 19.4 months (8.6–102.5). Nine patients had mitral valve reoperation, six had MVR, and three had clot removal from the mitral valve. There was no effect for age group on reoperation (SHR 0.89 (95% CI 0.27–2.87), P = 0.84). Valve size significantly affected reoperation (SHR 0.39 (95% CI 0.18–0.87), P = 0.02). The supra-annular position was associated with an increased risk of reoperation (SHR 3.1 (95% CI 1.003–9.4), P = 0.049). There was no difference in survival according to the age (Log-rank P = 0.57) or valve size (Log-rank P = 0.66). Mitral valve replacement in children is associated with low morbidity and mortality. The risk of reoperation could be affected by the valve size and position rather than the age.

Long-term outcomes of mitral valve replacement in patients weighing less than 10 kg

Background

The outcomes of mitral valve replacement (MVR) in pediatrics especially in the patients weighing less than 10 kg are not always favorable. This study aimed to measure long-term outcomes of MVR in our institution.

Methods

Nine young children weighing less than 10 kg underwent MVR with mechanical prostheses were enrolled in this retrospectively study. Kaplan–Meier survival analysis was used for the prediction of freedom from death and adverse events. Chi-square test was performed to compare outcomes for patients with different ratios of mechanical prosthesis size and body weight. Fourteen related literatures were also reviewed to support our study.

Results

All patients received bileaflet mechanical prostheses replacement. The surgical technique varied among the patients with prostheses implanted in the intra-annular (n = 5), supra-annular (n = 1), or with a Dacron conduit segment in the supra-annular position (n = 3). The valve size/weight ratio ranged from 2.11 to 5.00. There were two early death and one late death post-operation. The mean follow-up period was 80.67 ± 63.37 months, the transvalvular gradient was 10.5 ± 1.76 mmHg (range 8 to 12) and the peak gradient of LVOT was 5.00 ± 0.64 mmHg. One (11.1%) patient underwent an immediate revision MVR after initial MVR due to the periprosthetic leak. No patients required surgical reintervention or permanent pacemaker placement during long-term follow-up.

Conclusions

The tailored surgical strategy utilized for MVR in infants resulted in reliable valve function and excellent survival. Although revision is inevitable due to somatic growth, the bileaflet mechanical prostheses displayed appropriate durability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01443-9.

Melody valve to replace the mitral valve in small children: Lessons learned

Objective:

Infants requiring mitral valve replacement have few viable options. Recently, stented bovine jugular vein graft (Melody) has been surgically implanted in such cases. Herein, we report our experience, elaborating on evolution of implantation technique, pitfalls, as well as long-term outcome (including late dilatability).

Methods:

Seven Melody valves were implanted (2013–2019). The median patient age and weight were 6.7 (1.8–30.5) months and 5.8 (4.6–9.5) kg, respectively. The indications for implantation were mitral stenosis and/or regurgitation postatrioventricular septal defect (AVSD) repair (5), congenital mitral valve dysplasia (1), and Shone's complex (1). Operative technique involved shortening the valve and creating a neo-sewing ring at 2/3 (atrial)–1/3 (ventricular) junction. Implantation was followed by intraoperative balloon dilatation.

Results:

Five out of seven patients survived the perioperative period (one death due to technical failure and the other due to acute respiratory distress syndrome postcardiopulmonary bypass). Two out of five medium-term survivors got transplanted (1) or died due to acute myeloid leukemia (1). No valves were replaced. The mean echo gradient at discharge was a median 4 (2–6) mmHg. None of the patients showed left ventricular outflow tract or pulmonary venous obstruction. Two Melody valves were dilated late (5 months and 3 years postoperatively), resulting in decreasing mean gradients from 6 to 1 and from 17 to 4 mmHg. At last follow-up, surviving Melody had a mean gradient of 4 (1–9) mmHg.

Conclusions:

Mitral valve replacement with a Melody valve is feasible in infants, is reproducible, shows good immediate results, and offers the possibility of later dilatation. This technique offers a better solution compared to the existing alternatives for infants requiring a prosthetic mitral valve.

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.

Debate - Replacement of the Mitral Valve Under One Year of Age: Mechanical Valves Should Be Used

This article reviews the literature, focusing on publications from the third millennium and the results of mitral valve replacement in children younger than 1 year of age. Special consideration has been given to neonatal and infant valve replacement to provide insights into valve choice and technique. Mitral valve replacement is an important topic because it carries the highest mortality and poorer long-term prognosis than any other valve replacement in children.

Mechanical Mitral Valve Replacement: A Multicenter Study of Outcomes With Use of 15- to 17-mm Prostheses

BACKGROUND

The aim of this study was to evaluate early and mid-term outcomes (mortality and prosthetic valve reintervention) after mitral valve replacement with 15- to 17-mm mechanical prostheses.

METHODS

A multicenter, retrospective cohort study was performed among patients who underwent mitral valve replacement with a 15- to 17-mm mechanical prosthesis at 6 congenital cardiac centers: 5 in The Netherlands and 1 in the United States. Baseline, operative, and follow-up data were evaluated.

RESULTS

Mitral valve replacement was performed in 61 infants (15 mm, n = 17 [28%]; 16 mm, n = 18 [29%]; 17 mm, n = 26 [43%]), of whom 27 (47%) were admitted to the intensive care unit before surgery and 22 (39%) required ventilator support. Median age at surgery was 5.9 months (interquartile range [IQR] 3.2-17.4), and median weight was 5.7 kg (IQR, 4.5-8.8). There were 13 in-hospital deaths (21%) and 8 late deaths (17%, among 48 hospital survivors). Major adverse events occurred in 34 (56%). Median follow-up was 4.0 years (IQR, 0.4-12.5) First prosthetic valve replacement (n = 27 [44%]) occurred at a median of 3.7 years (IQR, 1.9-6.8). Prosthetic valve endocarditis was not reported, and there was no mortality related to prosthesis replacement. Other reinterventions included permanent pacemaker implantation (n = 9 [15%]), subaortic stenosis resection (n = 4 [7%]), aortic valve repair (n = 3 [5%], and aortic valve replacement (n = 6 [10%]).

CONCLUSIONS

Mitral valve replacement with 15- to 17-mm mechanical prostheses is an important alternative to save critically ill neonates and infants in whom the mitral valve cannot be repaired. Prosthesis replacement for outgrowth can be carried out with low risk.

Outcomes of Supra-annular Mechanical Atrioventricular Valve Replacement with Polytetrafluoroethylene Graft in Infants and Children

Despite improvements in valve repair techniques, conditions in which infants and children need for mechanical valve replacement (MVR) are still present. We analyzed supra-annular MVR outcomes in infants and children with small annulus and compared them with conventional annular MVR outcomes. Data were collected retrospectively from medical records of infants and children (weighing < 20 kg) who underwent atrioventricular valve replacement with mechanical valve in Seoul National University Children's Hospital between December 1984 and January 2019. We identified 8 patients (median age 20 months, median weight 10.2 kg) who underwent supra-annular MVR with polytetrafluoroethylene graft (supra-annular group). The patients were diagnosed with congenital mitral valve malformation (5 patients), complete atrioventricular septal defect (2 patients), and functional single ventricle (1 patient). The implanted mechanical valve size ranged from 16 to 23 mm. Thirty-three patients (median age 40 months, median weight 13 kg) underwent conventional annular MVR (annular group). The survival rate was not significantly different between the supra-annular and annular groups (75.0 vs 78.8%, P = 0.816). In patients with biventricular repair (7 patients with supra-annular MVR and 28 patients with annular MVR), mechanical valve-to-mitral valve annulus size ratio was higher in the supra-annular group than in the annular group (1.24 ± 0.30 vs 0.96 ± 0.22, P = 0.035). No coronary complication or heart block were observed in the supra-annular group. Supra-annular MVR with polytetrafluoroethylene graft may be a feasible surgical option in children with a small annulus when valve repair is unsuccessful.

Outcomes of mitral valve replacement with bileaflet mechanical prosthetic valve in children

OBJECTIVES

We examined the outcomes following mitral valve replacement with bileaflet mechanical prosthetic valve in children and identified the predictors for mortality and reoperation.

METHODS

Medical records from 49 children who underwent mitral valve replacement between 1982 and 2015 were reviewed retrospectively. Median age and body weight at initial mitral valve replacement were 2.4 years and 9.7 kg, respectively. The median follow-up was 13 years. Surgical results and predictors for mortality and reoperation were investigated.

RESULTS

There was no operative mortality; eight late deaths occurred. The actuarial survival rates were 89.5%, 84.2%, and 80.7% at 5, 10, and 15 years, respectively, after initial mitral valve replacement. The actuarial freedom rates from related complications were 89.5%, 78.3%, and 70.7% at 5, 10, and 15 years, respectively. Nineteen patients required 1st re-mitral valve replacement at a median of 5.9 years; six of these 19 required 2nd re-mitral valve replacement at a median of 8.9 years after 1st re-MVR. The actuarial freedom rates from re-mitral valve replacement were 86.0%, 56.8%, and 44.2% at 5, 10, and 15 years, respectively. No predictor for death was determined; however, the predictor for re-mitral valve replacement was initial valve diameter less than 19 mm.

CONCLUSIONS

Survival outcomes among children after mitral valve replacement with bileaflet mechanical prosthetic valve in biventricular heart were satisfactory. However, complications, including re-mitral valve replacement, were frequent and the predictor was of a small prosthesis size.

Surgical Atrioventricular Valve Replacement With Melody Valve in Infants and Children

Background Pediatric patients with atrioventricular valve disease have limited options for prosthetic valve replacement in sizes <15 mm. Based on successful experience with the stented bovine jugular vein graft (Melody valve) in the right ventricular outflow tract, the prosthesis has been modified for surgical valve replacement in pediatric patients with atrioventricular dysfunction with the intention of subsequent valve expansion in the catheterization laboratory as the child grows. Methods and Results A multicenter, retrospective cohort study was performed among patients who underwent atrioventricular valve replacement with Melody valve at 17 participating sites from North America and Europe, including 68 patients with either mitral (n=59) or tricuspid (n=9) replacement at a median age of 8 months (range, 3 days to 13 years). The median size at implantation was 14 mm (range, 9-24 mm). Immediately postoperatively, the valve was competent with low gradients in all patients. Fifteen patients died; 3 patients underwent transplantation. Nineteen patients required reoperation for adverse outcomes, including valve explantation (n=16), left ventricular outflow tract obstruction (n=1), permanent pacemaker implantation (n=1), and paravalvular leak repair (n=1). Twenty-five patients underwent 41 episodes of catheter-based balloon expansion, exhibiting a significant decrease in median gradient ( P<0.001) with no significant increase in grade of regurgitation. Twelve months after implantation, cumulative incidence analysis indicated that 55% of the patients would be expected to be free from death, heart transplantation, structural valve deterioration, or valve replacement. Conclusions The Melody valve is a feasible option for surgical atrioventricular valve replacement in patients with hypoplastic annuli. The prosthesis shows acceptable short-term function and is amenable to catheter-based enlargement as the child grows. However, patients remain at risk for mortality and structural valve deterioration, despite adequate early valvular function. Device design and implantation techniques must be refined to reduce complications and extend durability. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT02505074.

Patient-Specific Approach to Mitral Valve Replacement in Infants Weighing 10 kilograms or less

Background:

Mitral valve replacement (MVR) is the only option for infants with severe mitral valve disease that is not reparable; however, previously reported outcomes are not always favorable. Our institution has followed a tailored approach to sizing and positioning of mechanical valve prostheses in infants requiring MVR in order to obtain optimal outcomes.

Methods:

Outcomes for 22 infants ≤10 kg who have undergone MVR in Sydney, Australia, from 1998 to 2016, were analyzed. Patients were at a mean age of 6.8 ± 4.1 months (range: 0.8-13.2 months) and a mean weight of 5.4 ± 1.8 kg at the time of MVR. Most patients (81.8%) had undergone at least one previous cardiac surgical procedure prior to MVR, and 36.4% had undergone two previous procedures. Several surgical techniques were used to implant mechanical bileaflet prostheses.

Results:

All patients received bileaflet mechanical prostheses, with 12 receiving mitral prostheses and 10 receiving inverted aortic prostheses. Surgical technique varied between patients with valves implanted intra-annularly (n = 6), supra-annularly (n = 11), or supra-annularly with a tilt (n = 5). After a mean follow-up period of 6.2 ± 4.4 years, the survival rate was 100%. Six (27.3%) patients underwent redo MVR a mean of 102.2 ± 10.7 months after initial MVR. Four (18.2%) patients required surgical reintervention for development of left ventricular outflow tract obstruction and three (13.6%) patients required permanent pacemaker placement during long-term follow-up.

Conclusions:

The tailored surgical strategy utilized for MVR in infants at our institution has resulted in reliable valve function and excellent survival. Although redo is inevitable due to somatic growth, the bileaflet mechanical prostheses used displayed appropriate durability.

Bio-Chimney Technique for Narrow Mitral Annulus in Adults

Narrow mitral annulus is a common situation faced in adult patients. Choice of prosthetic valve in such cases is unclear. There are reported experiences with supra-annular mitral valve, Manouguian technique, "chimney technique" with mechanical valve and Melody valve, the latter two being in children. We report a novel "bio-chimney" technique in which a bioprosthetic valve of a size appropriate for the patient is sutured to a polyester vascular graft, which is then implanted to the native narrow mitral annulus in an adult patient, with promising initial results.

Echocardiographic assessment of prosthetic mitral valves in children

AIMS

We studied how Doppler-derived hemodynamic parameters in children change as the relative prosthetic mitral valve (PMV) size decreases with somatic growth and evaluated the diagnostic utility of the parameters for detecting PMV obstruction in children.

METHODS AND RESULTS

We reviewed 26 echocardiographic examination results of 15 mechanical bileaflet PMVs in 12 children. The median age at echocardiographic examination was 6.6 (0.6-18.1) years. The PMV functioned normally in 24 examinations but was obstructed due to thrombosis in two cases. PMV sizes ranged between 16 and 25 mm, which were standardized to body surface area (BSA) at the examination with z-score calculations. We assessed the peak E velocity, mean pressure gradient (PG), and pressure half time (PHT) of the transprosthetic flow, the velocity-time integral (VTI) ratio of the PMV inflow to the left ventricular outflow, and the BSA-indexed effective orifice area (iEOA) of the PMV calculated with the continuity equation. Linear regression analysis revealed statistically significant correlations between all parameters of normally functioning PMVs and the PMV size z-scores (Pearson correlation coefficients: peak E velocity, -0.68; mean PG, -0.71; PHT, -0.82; VTI ratio, -0.76; iEOA, 0.79). Compared with the predictive values derived from the regression equations, the VTI ratio and iEOA exceeded ± 2 standard errors in both patients with obstructive PMVs.

CONCLUSION

To assess PMV function in children, Doppler-derived hemodynamic parameters should be compared with their predictive values based on relative PMV sizes. The deviation of the VTI ratio and iEOA from their predictive values may indicate prosthetic obstruction.

Assessment of the Melody valve in the mitral position in young children by echocardiography

OBJECTIVES

Mitral valve replacement (MVR) in young children is limited by the lack of small prostheses. Our institution began performing MVR with modified, surgically placed, stented jugular vein grafts (Melody valve) in 2010. We sought to describe key echocardiographic features for pre- and postoperative assessment of this novel form of MVR.

METHODS

The pre- and postoperative echocardiograms of 24 patients who underwent Melody MVR were reviewed. In addition to standard measurements, preoperative potential measurements of the mitral annulus were performed whereby dimensions were estimated for Melody sizing. A ratio of the narrowest subaortic region in systole to the actual mitral valve dimension (SubA:MV) was assessed for risk of postoperative left ventricular outflow tract obstruction (LVOTO).

RESULTS

Melody MVR was performed at a median of 8.5 months (5.6 kg) for stenosis (5), regurgitation (3), and mixed disease (16). Preoperatively, actual mitral z scores measured hypoplastic (median -3.1 for the lateral [lat] dimension; -2.1 for the anteroposterior [AP] dimension). The potential measurements often had normal z scores with fair correlation with intraoperative Melody dilation (ρ = 0.51 and 0.50 for lat and AP dimensions, respectively, both P = .01). A preoperative SubA:MV <0.5 was associated with postoperative LVOTO, which occurred in 4 patients. Postoperatively, mitral gradients substantially improved, with low values relative to the effective orifice area of the Melody valve. No patients had significant regurgitation or perivalvar leak.

CONCLUSIONS

Preoperative echocardiographic measurements may help guide intraoperative sizing for Melody MVR and identify patients at risk for postoperative LVOTO. Acute postoperative hemodynamic results were favorable; however, ongoing assessment is warranted.

Supra-annular mitral valve implantation in very small children

OBJECTIVE

Mitral valve replacement (MVR) is a surgical option when mitral valvuloplasty is not feasible/successful. This study reviews our experience with MVR in very young children.

METHODS

From July 2004 to January 2014, seven children (mean age 13.3 ± 11.2 months; range 4 months to 35 months; mean body weight 6.0 ± 2.2 kg) underwent MVR with a mechanical prosthesis in the supra-annular position. To provide better exposure in the left atrium, we performed in all but one case a biatrial transeptal incision according to Guiraudon. Six patients had congenital defects of the mitral valve and one had rheumatic. Six patients had undergone previous cardiosurgical procedures.

RESULTS

All patients were implanted with a CarboMedics (CarboMedics, Austin, TX, USA) mechanical prosthesis. Mean prosthesis size was 19.0 ± 3.1 mm (range 16 to 25). There were no cases of operative or late mortality. At follow-up (mean 67.1 ± 34.8 months; range 25 to 108 months) two patients (28.6%) required reoperation both for thrombotic pannus formation over the disc at two and three months from first operation, respectively; only in one case was replacement necessary.

CONCLUSION

Supra-annular MVR may be considered a feasible secondary surgical option in children with a small annulus when mitral valvuloplasty is unsuccessful or unsuitable. Early and mid-term outcomes are acceptable but complications are not uncommon, especially related to thrombotic events.

Valve replacement in children: a challenge for a whole life

Valvular pathology in infants and children poses numerous challenges to the paediatric cardiac surgeon. Without question, valvular repair is the goal of intervention because restoration of valvular anatomy and physiology using native tissue allows for growth and a potentially better long-term outcome. When reconstruction fails or is not feasible, valve replacement becomes inevitable. Which valve for which position is controversial. Homograft and bioprosthetic valves achieve superior haemodynamic results initially but at the cost of accelerated degeneration. Small patient size and the risk of thromboembolism limit the usefulness of mechanical valves, and somatic outgrowth is an universal problem with all available prostheses. The goal of this article is to address valve replacement options for all four valve positions within the paediatric population. We review current literature and our practice to support our preferences. To summarize, a multitude of opinions and surgical experiences exist. Today, the valve choices that seem without controversy are bioprosthetic replacement of the tricuspid valve and Ross or Ross-Konno procedures when necessary for the aortic valve. On the other hand, bioprostheses may be implanted when annular pulmonary diameter is adequate; if not or in case of right ventricular outflow tract discontinuity, it is better to use a pulmonary homograft with the Ross procedure. Otherwise, a valved conduit. Mitral valve replacement remains the most problematic; the mechanical prosthesis must be placed in the annular position, avoiding oversizing. Future advances with tissue-engineered heart valves for all positions and new anticoagulants may change the landscape for valve replacement in the paediatric population.

Long-term results of mitral valve repair for severe mitral regurgitation in infants: fate of artificial chordae

BACKGROUND

The experience with mitral valve repair for severe mitral regurgitation in infants was retrospectively reviewed.

METHODS

From 1978 to 2009, 15 infant patients (4 boys, 7.2±3.2 months old) underwent mitral valve repair for severe mitral regurgitation. The etiology of mitral regurgitation according to Carpentier classification was type I in 1 patient, type II in 10 patients, and type III in 4 patients. Artificial chordal replacement was performed in 11 patients. The follow-up course was completed in all patients, with a median follow-up period of 10.2 years (range, 2.2 to 33.4 years).

RESULTS

There were no operative or in-hospital mortalities. The actuarial survival and freedom from reoperation rates at 10 years were 89% and 65%, respectively. Five patients required redo mitral valve surgery, including 4 patients needing mitral valve replacement. Three of 4 patients with type III mitral regurgitation, caused by congenital subvalvar structural abnormality, required redo mitral valve surgery. In 11 patients who underwent artificial chordal reconstruction, 2 (18%) required mitral valve replacement during the early postoperative period, whereas the remaining patients showed no recurrent mitral regurgitation during the entire study period. The latest echocardiography findings at 7.3 years after the operation showed that the left ventricular diastolic diameter, mitral valve diameter, and ejection fraction were 99.2%±5.0% of normal, 101.7%±13.3% of normal, and 0.741±0.058, respectively.

CONCLUSIONS

Long-term durability of mitral valve repair for severe mitral regurgitation in infants was satisfactory. Artificial chordal reconstruction is an effective procedure without an elevated risk of late reoperation.