Hugo Loyola

Evaluating Failing Fontans for Heart Transplantation: Predictors of Death

BACKGROUND Late complications of the Fontan operation represent a significant management challenge. Failing Fontan patients have two modes of presentation: impaired ventricular function (IVF) and those with preserved ventricular function (PVF) but with failing Fontan physiology (protein-losing enteropathy [PLE] and plastic bronchitis [PB]). This study evaluated whether failing Fontan patients referred for heart transplantation had a different outcome based on the mode of presentation. METHODS The medical records of all Fontan patients evaluated for heart transplantation at a single institution from 1994 to 2008 were retrospectively reviewed. Demographic, hemodynamic, and laboratory data were collected. Patients were stratified into an IVF or PVF group by echocardiographic criteria. Descriptive statistics and Kaplan-Meier analysis were used for hypothesis testing. RESULTS Thirty-four Fontan patients were evaluated for heart transplantation. According to echo description of systolic function, 18 were categorized as IVF and 16 as PVF. The IVF group had a significantly lower cardiac index and venous oxygen saturation, and significantly higher systemic vascular resistance vs the PVF group (p < 0.05). PLE or PB was present in 13 PVF patients and none in the IVF group. Twenty patients underwent transplantation, with similar rates amongst the IVF and PVF groups. Within 1 year from evaluation, 2 IVG patients and 7 PVF patients had died (p = 0.052). CONCLUSIONS Failing Fontan patients with PVF have decreased overall survival independent of whether they underwent transplantation. This trend indicates a need to improve the management and timing for transplantation amongst this population.

Stereoscopic vision display technology in real-time three-dimensional echocardiography-guided intracardiac beating-heart surgery

OBJECTIVE Stereoscopic vision display technology has been shown to be a useful tool in image-guided surgical interventions. However, the concept has not been applied to 3-dimensional echocardiography-guided cardiac procedures. We evaluated stereoscopic vision display as an aid for intracardiac navigation during 3-dimensional echocardiography-guided beating-heart surgery in a model of atrial septal defect closure. METHODS An atrial septal defect (6 mm) was created in 6 pigs using 3-dimensional echocardiography guidance. The defect was then closed using a catheter-based patch delivery system, and the patch was attached with tissue mini-anchors. Stereoscopic vision was generated with a high-performance volume renderer with stereoscopic glasses. Three-dimensional echocardiography with stereoscopic vision display was compared with 3-dimensional echocardiography with standard display for guidance of surgical repair. Task performance measures for each anchor placement (N = 32 per group) were completion time, trajectory of the tip of the anchor deployment device, and accuracy of the anchor placement. RESULTS The mean time of the anchor deployment for stereoscopic vision display group was shorter by 44% compared with the standard display group: 9.7 +/- 0.9 seconds versus 17.2 +/- 0.9 seconds (P < .001). Trajectory tracking of the anchor deployment device tip demonstrated greater navigational accuracy measured by trajectory deviation: 3.8 +/- 0.7 mm versus 6.1 +/- 0.3 mm, 38% improvement (P < .01). Accuracy of anchor placement was not significantly different: 2.3 +/- 0.3 mm for the stereoscopic vision display group versus 2.3 +/- 0.3 mm for the standard display group. CONCLUSION Stereoscopic vision display combined with 3-dimensional echocardiography improved the visualization of 3-dimensional echocardiography ultrasound images, decreased the time required for surgical task completion, and increased the precision of instrument navigation, potentially improving the safety of beating-heart intracardiac surgical interventions.

Right ventricular papillary muscle approximation as a novel technique of valve repair for functional tricuspid regurgitation in an ex vivo porcine model

OBJECTIVES Annuloplasty for functional tricuspid regurgitation may sometimes be ineffective because of chamber dilation and valve tethering. This study compared a novel technique, right ventricle (RV)-papillary muscle approximation, with annuloplasty in experimentally-produced tricuspid regurgitation. METHODS RVs of isolated porcine hearts (n = 10) were statically pressurized, which led to RV dilation and central tricuspid regurgitation. Regurgitant flow was measured with a saline solution-filled column. The head of the anterior papillary muscle was approximated to 4 points on the ventricular septum. Next, a prosthetic ring was implanted, and then RV-papillary muscle approximation was combined. Tricuspid annular dimension, RV geometry, and tricuspid valve tethering were analyzed with 3-dimensional echocardiography. RESULTS Tricuspid regurgitation (2270 ± 186 mL/min) was reduced by RV-papillary muscle approximation alone (214 ± 45 mL/min; P < .05) more than by annuloplasty alone (724 ± 166 mL/min; P < .05). Combined RV-papillary muscle approximation and annuloplasty resulted in the least regurgitation (80 ± 39 mL/min). RV-papillary muscle approximation reduced tricuspid septolateral diameter (25%; P < .05), and annular area (23%; P < .05), as did annuloplasty. RV-papillary muscle approximation also reduced RV sphericity index (33%; P < .05) and tricuspid tethering height (54%; P < .05), whereas annuloplasty did not. Direction of RV-papillary muscle approximation did not independently affect outcomes. CONCLUSIONS This ex vivo study suggests that RV-papillary muscle approximation potentially repairs tricuspid regurgitation better than annuloplasty by improving ventricular sphericity and valve tethering as well as annular dimension.

Mechanisms of tricuspid regurgitation in patients with hypoplastic left heart syndrome undergoing tricuspid valvuloplasty

OBJECTIVES Tricuspid regurgitation (TR) remains a risk factor for morbidity and mortality through staged palliation in patients with hypoplastic left heart syndrome (HLHS). Reports on the mechanisms associated with TR in patients with HLHS are limited. Thus, we sought to describe our experience with tricuspid valve (TV) repair in these patients, focusing on the mechanisms of TR and corresponding surgical techniques. METHODS We performed a retrospective single-center review (January 2000 to December 2012) of patients with HLHS undergoing TV repair and completing Fontan circulation. We evaluated the pre- and postoperative echocardiograms, intraoperative findings, and surgical techniques used. RESULTS A total of 53 TV repairs were performed in 35 patients with HLHS completing staged palliation. TV repairs were performed at stage II in 15, between stage II and III in 4, at stage III in 27, and after stage III in 7. The surgical techniques for valvuloplasty included annuloplasty (38%), anteroseptal (AS) commissuroplasty (66%), anterior papillary muscle repositioning (11%), multiple commissuroplasties (9%), septal-posterior commissuroplasty (9%), and fenestration closure (4%). The predominant jet of TR emanated along the AS commissure in 68% of the cases. All patients survived the procedure and were discharged. Preoperative echocardiography showed a dilated TV annulus on the lateral dimension, anteroposterior dimension, and area that was significantly reduced after TV repair (P < .0001). The preoperative mean TR, as assessed by lateral (P = .002) and anteroposterior (P = .005) vena contracta, was also significantly reduced after TV repair. TV repair did not significantly affect right ventricular systolic function immediately after surgery (P = .17) or at the most recent follow-up visit (P = .52). Patients with anterior leaflet prolapse were at increased risk of worse outcomes, including moderate or greater right ventricular dysfunction (P = .02). Patients requiring reoperation for TV repair were younger (6.3 vs 28.1 months, P < .0001) at the initial operation. One patient died of heart failure. Freedom from TV replacement and transplant-free survival were both 97% at the most recent follow-up point. CONCLUSIONS TR in patients with HLHS commonly emanates from the AS commissure. The associated mechanisms are often annular dilatation and anterior leaflet prolapse. Preoperative anterior leaflet prolapse was associated with worse outcomes. Annuloplasty, closure of the AS commissure, and repositioning of the anterior papillary muscle are effective in addressing TR in the short- and mid-term in this challenging population.

Atrioventricular valve annular remodeling with a bioabsorbable ring in young children.

To the Editor: Atrioventricular (AV) valve repair for regurgitation has been shown to be preferable to valve replacement in young children ([1][1]). Besides valvuloplasty technique, annulus reduction and stabilization with a ring have been demonstrated to be necessary to maintain effective leaflet

Changes in left atrioventricular valve geometry after surgical repair of complete atrioventricular canal

OBJECTIVE The most common reason for late surgical reintervention after repair of complete atrioventricular canal defects is the development of left atrioventricular valve regurgitation. We sought to determine the changes in left atrioventricular valve geometry after surgical repair that may predispose to regurgitation. METHODS Atrioventricular valve measurements were obtained by 2-dimensional echocardiography at 3 different time points (preoperative, early postoperative, and midterm postoperative [6-12 months]). Left atrioventricular valve annulus area and left ventricular volume were calculated; vena contracta of the regurgitant jet orifice was measured. All measurements were normalized relative to an appropriate power of body surface area. RESULTS From January 2000 to January 2008, 101 patients with complete atrioventricular canal repair were included. Left atrioventricular valve annulus was noted to remodel from an elliptical shape to a circular shape after surgery. Left atrioventricular valve annulus area increased early postoperatively (systole: 4.1 ± 0.2 cm(2)/m(2) vs 6.1 ± 0.3 cm(2)/m(2), P < .001; diastole: 7.2 ± 0.4 cm(2)/m(2) vs 10.0 ± 0.5 cm(2)/m(2), P < .001, pre- vs postoperative, respectively). This increase was sustained in the midterm postoperative period (systole: 6.1 ± 0.3 cm(2)/m(2), P = .85, vs diastole: 10.0 ± 0.4 cm(2)/m(2), P = .78, early vs midterm postoperative). Left ventricular volume increased in the early and midterm postoperative periods compared with preoperative (systole: 16.9 ± 1.2 mL/m(2) vs 26.2 ± 1.7 mL/m(2), P < .001; diastole: 35.0 ± 2.4 mL/m(2) vs 52.5 ± 3.2 mL/m(2), P < .001). CONCLUSIONS Complete atrioventricular canal repair leads to left atrioventricular valve annular shape change with increased area and circular shape. The change in left atrioventricular valve annulus shape appeared to be mainly due to increased circumference in the posterior free wall of the annulus. These findings may provide a mechanism for the progression of central regurgitation seen after complete atrioventricular canal repair and a potential solution.

The Safety and Efficacy of Antifibrinolytic Therapy in Neonatal Cardiac Surgery

Background Neonates undergoing open-heart surgery are particularly at risk of postoperative bleeding requiring blood transfusion. Aprotinin has attained high efficacy in reducing the requirement for a blood transfusion following a cardiopulmonary bypass, but is seldom studied in the neonatal age group. The aim of this study was to compare the efficacy and adverse effects of aprotinin and tranexamic acid in neonates undergoing open-heart surgery at a single centre. Methods Between October 2003 and March 2008, perioperative data of 552 consecutive neonatal patients undergoing open-heart surgery in Children’s Hospital Boston were reviewed. Among them, 177 did not receive antifibrinolytic therapy (Group A); 100 were treated with tranexamic acid only (Group B); and 275 patients received aprotinin with or without tranexamic acid (Group C). Except for antifibrinolytic therapy, the anaesthesiological and surgical protocols remained identical. Postoperative complications and in-hospital mortality were the primary study endpoints. Results Body weight and Risk Adjustment for Congenital Heart Surgery (RACHS-1) scores were statistically comparable among the three groups. No statistically significant differences were observed between the duration of hospitalization, chest tube drainage, reexploration for bleeding, and kidney function impairment. In Group C, less blood was transfused within 24 hours than in GroupB. Operative mortality was similar among the three groups. Conclusion No further risk and kidney injury were observed in the use of aprotinin in neonatal cardiac surgery, aprotinin demonstrated a reduced requirement for blood transfusion compared with tranexamic acid. Our data provide reasonable evidence that aprotinin and tranexamic acid are safe and efficacious as antifibrinolytic modalities in neonatal patients undergoing cardiac surgery.

Lower mini-sternotomy in congenital heart disease, just a cosmetic improvement?

OBJECTIVES Lower mini-sternotomy represents a minimally invasive surgical technique that has been utilized for the repair of a wide variety of congenital heart defects with excellent surgical and cosmetic outcomes. However, clinical improvements provided for this technique beyond cosmetic results are controversial. The aim of our study is to report our results with lower mini-sternotomy for the repair of congenital heart malformations and compare them with a matched group with a full median sternotomy approach. METHODS From 2010 through 2013, 105 consecutive congenital patients (81 paediatric) underwent lower mini-sternotomy at our centre (Group 1). We analysed in-hospital and follow-up outcomes, and compare them with an age-sex-diagnosis-type of surgery-matched group (Group 2). Both groups were managed following the same clinical protocols. RESULTS In Group 1, age at the time of surgery was 12 ± 17 years (range from 0.2 to 64.6 years). In this group, 81 patients were paediatric and 62 were female. Operative techniques were atrial septal defect (n = 72), ventricular septal defect (n = 24) and atrioventricular canal repairs (n = 9). There were no deaths or major in-hospital complications. Two adult patients required conversion to full median sternotomy. For a medium follow-up of 1.5 years (range from 1 month to 5 years), there were no deaths, reinterventions or reoperations and no significant residual defects were found. Compared with Group 2, patients in Group 1 had longer cardiopulmonary bypass times (58.71 ± 19.08 vs 45.39 ± 20.45, P < 0.001) and cross-clamp times (32.75 ± 13.11 vs 23.22 ± 13.93, P < 0.001), higher rate of early extubation (96 vs 85%, P = 0.018) and lower rate of postoperative complications (11.6 vs 22.3%, P = 0.034). CONCLUSIONS At our centre, lower mini-sternotomy represents a safe alternative for the repair of congenital heart defects in paediatric and adult populations. Cardiopulmonary bypass and cross-clamp times were longer in the mini-sternotomy group. However, these patients showed earlier extubation and less postoperative complications when compared with patients with a full sternotomy approach. Combined with improved cosmetic outcomes, lower mini-sternotomy could represent the technique of choice for these populations.

Evaluating Failing Fontans for Heart Transplantation: Predictors of Mortality

BACKGROUND Late complications of the Fontan operation represent a significant management challenge. Failing Fontan patients have two modes of presentation: impaired ventricular function (IVF) and those with preserved ventricular function (PVF) but with failing Fontan physiology (protein-losing enteropathy [PLE] and plastic bronchitis [PB]). This study evaluated whether failing Fontan patients referred for heart transplantation had a different outcome based on the mode of presentation. METHODS The medical records of all Fontan patients evaluated for heart transplantation at a single institution from 1994 to 2008 were retrospectively reviewed. Demographic, hemodynamic, and laboratory data were collected. Patients were stratified into an IVF or PVF group by echocardiographic criteria. Descriptive statistics and Kaplan-Meier analysis were used for hypothesis testing. RESULTS Thirty-four Fontan patients were evaluated for heart transplantation. According to echo description of systolic function, 18 were categorized as IVF and 16 as PVF. The IVF group had a significantly lower cardiac index and venous oxygen saturation, and significantly higher systemic vascular resistance vs the PVF group (p < 0.05). PLE or PB was present in 13 PVF patients and none in the IVF group. Twenty patients underwent transplantation, with similar rates amongst the IVF and PVF groups. Within 1 year from evaluation, 2 IVG patients and 7 PVF patients had died (p = 0.052). CONCLUSIONS Failing Fontan patients with PVF have decreased overall survival independent of whether they underwent transplantation. This trend indicates a need to improve the management and timing for transplantation amongst this population.

Original articlePediatric cardiacEvaluating Failing Fontans for Heart Transplantation: Predictors of Death

BACKGROUND Late complications of the Fontan operation represent a significant management challenge. Failing Fontan patients have two modes of presentation: impaired ventricular function (IVF) and those with preserved ventricular function (PVF) but with failing Fontan physiology (protein-losing enteropathy [PLE] and plastic bronchitis [PB]). This study evaluated whether failing Fontan patients referred for heart transplantation had a different outcome based on the mode of presentation. METHODS The medical records of all Fontan patients evaluated for heart transplantation at a single institution from 1994 to 2008 were retrospectively reviewed. Demographic, hemodynamic, and laboratory data were collected. Patients were stratified into an IVF or PVF group by echocardiographic criteria. Descriptive statistics and Kaplan-Meier analysis were used for hypothesis testing. RESULTS Thirty-four Fontan patients were evaluated for heart transplantation. According to echo description of systolic function, 18 were categorized as IVF and 16 as PVF. The IVF group had a significantly lower cardiac index and venous oxygen saturation, and significantly higher systemic vascular resistance vs the PVF group (p < 0.05). PLE or PB was present in 13 PVF patients and none in the IVF group. Twenty patients underwent transplantation, with similar rates amongst the IVF and PVF groups. Within 1 year from evaluation, 2 IVG patients and 7 PVF patients had died (p = 0.052). CONCLUSIONS Failing Fontan patients with PVF have decreased overall survival independent of whether they underwent transplantation. This trend indicates a need to improve the management and timing for transplantation amongst this population.