[Complex right cervical aortic arch repair: less is more]. / Riparazione di arco aortico cervicale destroposto: "less is more".

Cervical aortic arch is a rare malformation that often has anatomical abnormalities of the supra-aortic trunks and may also be associated with aortic stenosis, aneurysms, or cardiac malformations. To correct them, symptomatic patients undergo surgery, which usually consists of a prosthetic graft repair, aortoplasty patch, or an end-to-end anastomosis. In addition, circulatory arrest and deep hypothermia are often required, as in aortic arch surgery. We report the case of a 13-year-old patient who underwent correction of a right cervical aortic arch stenosis with a post-stenotic aneurysm between the origin of the right carotid artery and the right subclavian artery. The anatomy of the aortic branches was abnormal. The surgical procedure consisted of an extensive resection with direct end-to-end anastomosis, without the use of a prosthetic graft, using moderate hypothermic cardiopulmonary bypass and without circulatory arrest.

Hemoadsorption Contribution in Failing Fontan Pediatric Heart Transplantation.

INTRODUCTION: A systemic inflammatory response is triggered in patients undergoing cardiothoracic surgery with cardiopulmonary bypass (CPB). This response is particularly evident in pediatric patients, especially those of low weight and after undergoing long CPB, and can severely impair the surgical result. Adsorptive blood purification techniques have been proposed to limit this systemic inflammatory response. To test its efficacy, we added the hemoadsorption filter Jafron HA 380 to CPB in a much compromised pediatric patient who underwent heart transplantation. METHODS: A 10-year-old single ventricle patient previously treated with Fontan operation was listed for heart transplantation due to the evidence of failing Fontan condition. He experienced many episodes of cardiac arrest and underwent heart transplantation in much compromised general and hemodynamic conditions. The hemoadsorption filter Jafron HA 380 was used for all the duration of CPB, and the inflammatory biomarker interleukin 6 (IL-6) was assayed. RESULTS: Postoperative outcome was uneventful and comparable to that of elective pediatric heart transplantation. IL-6 levels showed an impressive postoperative reduction, and after 2 days, the IL-6 level was comparable with a typical uneventful post-transplant course. CONCLUSIONS: The use of hemoadsorption filter can contribute to improve the pediatric transplant results, especially in very high-risk patients.

A geometry-based finite element tool for evaluating mitral valve biomechanics.

Mitral valve function depends on its complex geometry and tissue health, with alterations in shape and tissue response affecting the long-term restorarion of function. Previous computational frameworks for biomechanical assessment are mostly based on patient-specific geometries; however, these are not flexible enough to yield a variety of models and assess mitral closure for individually tuned morphological parameters or material property representations. This study details the finite element approach implemented in our previously developed toolbox to assess mitral valve biomechanics and showcases its flexibility through the generation and biomechanical evaluation of different models. A healthy valve geometry was generated and its computational predictions for biomechanics validated against data in the literature. Moreover, two mitral valve models including geometric alterations associated with disease were generated and analysed. The healthy mitral valve model yielded biomechanical predictions in terms of valve closure dynamics, leaflet stresses and papillary muscle and chordae forces comparable to previous computational and experimental studies. Mitral valve function was compromised in geometries representing disease, expressed by the presence of regurgitating areas, elevated stress on the leaflets and unbalanced subvalvular apparatus forces. This showcases the flexibility of the toolbox concerning the generation of a range of mitral valve models with varying geometric definitions and material properties and the evaluation of their biomechanics.

A toolbox for generating scalable mitral valve morphometric models.

The mitral valve is a complex anatomical structure, whose shape is key to several traits of its function and disease, being crucial for the success of surgical repair and implantation of medical devices. The aim of this study was to develop a parametric, scalable, and clinically useful model of the mitral valve, enabling the biomechanical evaluation of mitral repair techniques through finite element simulations. MATLAB was used to parameterize the valve: the annular boundary was sampled from a porcine mitral valve mesh model and landmark points and relevant boundaries were selected for the parameterization of leaflets using polynomial fitting. Several geometric parameters describing the annulus, leaflet shape and papillary muscle position were implemented and used to scale the model according to patient dimensions. The developed model, available as a toolbox, allows for the generation of a population of models using patient-specific dimensions obtained from medical imaging or averaged dimensions evaluated from empirical equations based on the Golden Proportion. The average model developed using this framework accurately represents mitral valve shapes, associated with relative errors reaching less than 10% for annular and leaflet length dimensions, and less than 24% in comparison with clinical data. Moreover, model generation takes less than 5 min of computing time, and the toolbox can account for individual morphological variations and be employed to evaluate mitral valve biomechanics; following further development and validation, it will aid clinicians when choosing the best patient-specific clinical intervention and improve the design process of new medical devices.

Malnutrition and chyle leakage: A life-threatening duo in heart transplantation post-Fontan procedure.

Protein-losing enteropathy and chyle leakage may lead to severe malnutrition in heart transplantation for failing Fontan. Nutritional management may be challenging from defining nutrient needs to diagnosis of malnutrition enteropathy, and expertise is necessary. Body composition and hematological nutritional indices may help define malnutrition severity and guide nutritional strategy.

Minimally Invasive Approach to Correct Anomalous Inferior Vena Cava Connection to the Left Atrium.

Anomalous drainage of the inferior vena cava into the left atrium is a rare congenital condition. A 20-year-old girl was referred for recurrent transient ischemic attacks. Transthoracic echocardiography revealed a large ostium secundum atrial septal defect, and computed tomography showed anomalous drainage of the inferior vena cava into the left atrium. Through a right mini-thoracotomy, the opening of the inferior vena cava into the atrium was identified under the inferior edge of the interatrial septum, draining into the left atrium, and redirected to the right atrium, using a pericardial patch to reconstruct the atrial septum. Postoperative course was uneventful. Right mini-thoracotomy approach was effective in correcting the anomalous drainage of the inferior vena cava into the left atrium.

The Golden Proportion in the scallop geometry of normal mitral valves. When nature plays with jigsaw puzzles.

INTRODUCTION: The Golden Proportion is a particular geometric ratio between two segments. It results in an irrational number, commonly rounded to 1.618, or 0.618, and showing unique geometrical/mathematical properties. Its presence has been documented in a huge amount of natural settings, as well as the human body and the heart. In light of a previous research of ours, about its presence in the Coaptation Triangle, we investigated the dimensions of both mitral leaflets in healthy mitral valves and then compared our results to literature data, in order to search whether this proportional pattern could be extended to other valve aspects. METHODS AND RESULTS: Forty-one adults, with healthy mitral valves, underwent 2D echocardiography. Adequate long-axis three-chamber view images were chosen, at mid-diastole, where the central scallop of both the anterior and posterior leaflets (A2 and P2, respectively) could be well identified and measured. We then investigated these measurements, calculating their ratio and comparing our findings to literature data on normal mitral anatomy. The ratio between the two scallop heights appeared very close to the Golden Ratio. Literature data supported our results and, apparently, showed the mitral leaflets to be like a jigsaw puzzle of components highly interconnected each other with an extremely simple geometry, based on the Golden Proportion. CONCLUSION: The Golden Proportion looks to determine the geometry of normal mitral scallops. Studying such a pattern of anatomical proportions could improve surgical techniques for conservative surgery, as well as innovate the design of mitral repair rings and valve prostheses.

Colchicine: An Impressive Effect on Posttransplant Capillary Leak Syndrome and Renal Failure.

Capillary leak syndrome is a critical condition occasionally occurring posttransplant and is characterized by acute endothelial hyperpermeability leading to systemic protein-rich fluid extravasation and consequent hypovolemia, hypoperfusion, and acute kidney injury. Treatment is merely supportive and is based on osmotic drugs, diuretics, continuous renal replacement therapy, and surgical drainage. However, removal of the underlying inflammatory cause is mandatory to achieve stable resolution. Herein, we report the first successful treatment with colchicine in 2 life-threatening pediatric cases of capillary leak syndrome with renal failure occurring after transplant (heart and bone marrow) and unresponsive to any other line of therapy. Both cases were only palliated by supportive therapy and revealed an impressively rapid response to colchicine both in terms of diuresis and clinical condition recovery, allowing for the cessation of renal replacement therapy in a few hours. In both patients, colchicine was temporarily discontinued for transient leukopenia (attributed to an additive effect with mycophenolate mofetil), resulting in extravasation, and renal failure recurrence was restored only after colchicine reintroduction. Although the association of colchicine with an immunosuppressive drug was formerly contraindicated, no other adverse events were noted when using a minimized dose. Both patients are now maintaining a good renal function without recurrence of extravasation after 6 months of follow-up. In conclusion, this strikingly positive experience forces physicians to consider this old and cost-effective drug as a new, powerful rescue tool in such critical cases.

Ventricular assist device in a failing total cavopulmonary connection: a new step-by-step approach.

The management of failing Fontan patients with mechanical circulatory support has been reported with unsatisfactory results. A 5-year-old girl, listed for heart transplantation for failing Fontan, underwent rescue extracorporeal membrane oxygenation support. As it was necessary to move the patient to the Berlin Heart Excor, a step-by-step approach was designed to obtain a gradual adaptation to this form of support. A central extracorporeal membrane oxygenation, with a Berlin Heart apical and aortic cannulae, was implanted leaving the previously positioned femoral vein cannula in parallel with the outflow apical one. The femoral vein cannula was removed when the lungs recovered from the effects of surgical trauma. Four days later, the Fontan fenestration was closed, and after 4 more days, a gradual reduction of gas support was planned without problems. Oxygenator was then removed, and 4 days later, a 30-ml Berlin Heart EXCOR ventricle replaced the centrifugal pump. This sequential approach, which has never been described before, can improve the results of the ventricular assist device support in failing Fontan patients, because it allows a gradual adaptation, even in patients with damaged lungs.

Coaptation Triangle and Golden Proportion in mitral valve anatomy. Does nature play with geometry?

INTRODUCTION: The Coaptation Triangle, or Tenting Area, can be identified on long-axis 2D images. Its assessment is a routine practice during echocardiographic mitral evaluation. The Golden Proportion is a particular geometric ratio between two segments. Its value is an irrational number, commonly rounded to 0.618 and showing unique geometrical/mathematical properties. Interestingly, its presence has been documented in an extremely variable number of natural settings. Hypothesizing the presence of the Golden Proportion in normal mitral anatomy, we examined the Coaptation Triangle of healthy valves to investigate such a theory. METHODS AND RESULTS: A total of 41 healthy adults, with normal mitral valves, underwent 2D echocardiography. Adequate images were chosen and loaded into custom software. Firstly, the Coaptation Triangle was manually drawn by the operator. Then, a second Coaptation Triangle, with the same base, but based on Golden Proportion, was automatically built by the software. Eventually, the two triangles were analyzed and compared. All retrieved measurements were investigated for differences and correlations. Ratios close to the Golden Proportion were found in several locations of the manually drawn Coaptation Triangle. On the other hand, comparing the manually drawn Coaptation Triangle with the automatically built one, no significant differences were revealed, and very strong correlations were demonstrated. CONCLUSION: The Golden Proportion appears present in the geometry of normal mitral valves. Studying such an aspect and identifying disruption in anatomical proportions could improve early diagnosis of mitral alterations, and allows a more standardized follow-up and help surgeons to plan a repair strategy, particularly quantifying the needed surgical modifications.

Liver stiffness modifications shortly after total cavopulmonary connection.

OBJECTIVES: Hepatic damage in Fontan circulation setting is well known. Mainly represented by fibrosis, it is still poorly understood. Transient hepatic elastography (Fibro-Scan) is a useful tool to test liver stiffness and is commonly used in the evaluation of liver fibrosis. Unfortunately, the increase of inferior vena cava pressure consequent to total cavopulmonary connection can probably interfere with Fibro-Scan evaluation altering the result evaluation with the conventional scale. To verify this hypothesis and to quantify the impact of venous pressure on Fibro-Scan results, we checked perioperative liver stiffness changes in patients undergoing total cavopulmonary connection. METHODS: A prospective observational study was carried out on 9 patients undergoing extracardiac total cavopulmonary connection. Mean age at operation was 4.3 ± 0.6 years, and mean weight 14 ± 2.4 kg. Hepatic stiffness was analysed with Fibro-Scan evaluation immediately before and 4 months after surgery. Results were matched with several perioperative data: pulmonary pressures, conduit size, fenestration, hepatic enzymes and coagulation setting. RESULTS: Preoperative hepatic stiffness was 6.2 ± 1.5 kPa, with a significant increase to 11.2 ± 4 kPa at a mean follow-up of 4 months (P < 0.01). Mean alanine aminotransferase was 16.9 ± 8.3 mg/dl preoperatively and 16.3 ± 8.7 mg/dl at discharge. Both values showed a significant correlation with liver stiffness raise, their Pearson Correlation Indexes being 0.8 and 0.7, respectively (P < 0.01). Mean aspartate aminotransferase/alanine aminotransferase ratio at discharge was 1.7 ± 0.5 and showed a significant negative correlation with liver stiffness raise, its Pearson Correlation Index being -0.7 (P < 0.01). CONCLUSIONS: Liver stiffness increases rapidly after total cavopulmonary connection and perioperative variations in some liver enzymes appear to correlate with this change. Since a true anatomical damage is known to develop gradually with Fontan circulation, early liver stiffness raise is likely due to parenchymal congestion only. Fibro-Scan can easily recognize and assess the entity of such a change. For these reasons, this diagnostic tool must be considered useful only to monitor liver stiffness changes and evolution with time, but a conventional evaluation of results, like in other acquired hepatic fibrosis, can be misleading.

Use of oversized injectable valves in growing children for total repair of right ventricular outflow tract anomalies (preliminary results).

Right ventricular outflow tract surgery was originally confined to transannular patching, in the belief that pulmonary regurgitation was well tolerated. Because follow-up evaluations revealed the deleterious effects of pulmonary regurgitation, surgery today aims to spare or replace the valve. Available replacement devices have short lifetimes, considering growth mismatch in children. We hypothesize that oversizing the right infundibulum anticipates growth and that a squeezed prosthesis can complete the expansion process. The No-React® Injectable BioPulmonic Valve is designed for right infundibular surgery in adults, and hundreds of implants have shown promising results. We used this device for surgery in babies, with the addition of an innovative oversizing technique. This study evaluates our preliminary results and investigates whether such a technique might reduce growth mismatch. From September 2010 through July 2012, we implanted 11 injectable pulmonic valves. The median age of our patients was 23 months. After opening the right infundibulum, we enlarged it as much as possible with a wide patch. Before completing the patch suture, we injected an oversized valve. No problems occurred during surgery. No major insufficiency or leak was observed. We conclude that prostheses can be quite oversized and perform well even when not completely expanded. Oversized injectable pulmonic valves, shrunken to a smaller diameter, enabled the implantation of a device wider than otherwise possible, without affecting performance. Moreover, the prosthesis tended to return to its original size following growth, thereby reducing growth mismatch. Longer follow-up and larger numbers of patients are needed for verification.

Repair of an unusual aortic coarctation using an extracellular matrix patch.

The surgical treatment of neonatal aortic coarctation is usually accomplished with a termino-terminal anastomosis or a subclavian flap. The use of a patch to enlarge the isthmal narrowing may be an alternative but is frequently complicated by aneurysmal dilatation on the aortic wall opposite to the patch, probably because it disrupts the vascular anatomic integrity. Extracellular matrix patches promise to restore the original tissue structure and could therefore be a valid alternative to other materials. We describe an aortic coarctation with an uncommon anatomic aspect treated with a CorMatrix (CorMatrix, Alpharetta, GA) extracellular matrix patch.

Rescue mitral valve repair one hour after birth.

Congenital mitral regurgitation is rare and usually part of complex cardiac anomalies. When needed, early surgery represents a great challenge. In small babies avoiding valve replacement is desirable, but valve repair may be extremely complex. We describe an isolated congenital mitral regurgitation, successfully treated with conservative surgery about 1 h after birth. In a 30-year-old pregnant woman, fetal echocardiography revealed mitral annular dilatation with massive regurgitation, functional aortic atresia and a very small patent foramen ovale. Realizing that the baby had a poor chance of survival after birth, a cesarean section was scheduled at 37 weeks of pregnancy. The procedure was performed in the operating room next to the cardiac surgery theatre, where the newborn was urgently transferred. After an unsuccessful attempt of percutaneous atrial septostomy, a rescue surgical mitral repair was performed. To avoid mitral replacement, moderate residual regurgitation was accepted. Postoperative hospital stay was 57 days and the baby was discharged in good clinical condition. Residual mitral regurgitation was moderate at discharge and decreased thereafter. During a five-year follow-up the child remained asymptomatic with normal growth. Preserved ventricular function and progressive volume reduction of left heart chambers were observed.

Pulmonary valve replacement with mechanical prosthesis: long-term results in 4 patients.

Pulmonary valve replacement is rarely performed and is usually done with biological prostheses or grafts. The use of mechanical prostheses is still a debated issue. We analyzed the outcome of 4 patients at 11 years after pulmonary valve replacement with a mechanical prosthesis. During follow-up, all patients remained asymptomatic, with no arrhythmias and good anticoagulation. An echocardiogram showed preserved ventricular contraction and normal function of the prostheses, with low pressure gradients. No infective endocarditis occurred. Mechanical prostheses appear to be a good choice for pulmonary valve replacement. Surgical and clinical results were satisfactory with no complications, acceptable pressure gradients, and good ventricular function after more than 10 years. Lifelong anticoagulation is mandatory, but this is usually well tolerated.