Alejandro Pontón

Surgery for rheumatic tricuspid valve disease: a 30-year experience.

OBJECTIVE This study was undertaken to assess factors influencing short- and long-term outcomes of surgery for rheumatic disease of the tricuspid valve. METHODS Between 1974 and 2005, a total of 328 consecutive patients (mean age 51.3 +/- 13.6 years) underwent tricuspid valve surgery for rheumatic disease. There were 12 cases of isolated tricuspid lesion, 199 of triple-valve disease, 114 of tricuspid and mitral valve disease, and 3 of aortic and tricuspid valve disease. Most patients (72%) had predominantly tricuspid regurgitation. Tricuspid valve prosthetic replacement was performed in 31 cases and valve repair in 297. RESULTS In-hospital mortality was 7.6%. Late mortality was 52.1%, whereas the expected mortality of the Spanish population of the same age was 24.2%. Predictors of in-hospital mortality were male sex, isolated tricuspid lesion, moderate aortic insufficiency, postclamping time, and tricuspid valve replacement. Mean follow-up was 8.7 years (range 1-31 years). Follow-up was 98.9% complete. Predictors of late mortality were age, New York Heart Association functional class IV, postclamping time, and mitral valve replacement. In total, 114 patients required valve reoperation, but only 4 (3.5%) for isolated tricuspid valve dysfunction. At 30 years, actuarial survival was 12.1% +/- 4.4%, actuarial freedom from reoperation was 27.5% +/- 5.8%, and actuarial freedom from valve-related complications was 2.0% +/- 1.3%. CONCLUSION Organic tricuspid valve disease associated with rheumatic mitral or aortic lesions increases hospital and late mortality, but valve repair compared favorably with valve replacement. Long-term results may be considered acceptable for otherwise incurable valve disease.

Combined Mitral and Tricuspid Valve Repair in Rheumatic Valve Disease Fewer Reoperations With Prosthetic Ring Annuloplasty

Background— We examined predictors of early and very long-term outcome after combined mitral and tricuspid valve repair for rheumatic disease. Methods and Results— Between 1974 and 2002, 153 consecutive patients (mean age, 46.0±13.2 years) underwent combined mitral and tricuspid valve repair for rheumatic disease. Mitral disease was predominantly stenosis (82.3%); 100% of patients had organic tricuspid valve disease, predominantly with regurgitation (53.6%) or some degree of tricuspid stenosis (46.4%). Mitral repair included commissurotomy in 132 patients (86.3%) associated with a flexible annuloplasty in 108. Tricuspid valve repair included flexible annuloplasty in 68 patients (44.4%) and suture annuloplasty in 20 patients (13.1%) combined with tricuspid commissurotomy in 62 patients (42.5%). Thirty-day mortality was 5.9%. Late mortality was 60.1%. The median follow-up was 15.8 years (interquartile range, 6 to 19 years). Follow-up was 97.9% complete. Age >65 years was the only predictor of late mortality. Kaplan-Meier survival probability was 74.4% at 10 years and 57.0% at 15 years. Sixty-three patients required valve reoperation (mitral valve, 59; tricuspid valve, 38). Predictors of valve reoperations were either mitral or tricuspid commissurotomy without associated prosthetic ring annuloplasty. At 20 years, Kaplan-Meier freedom from reoperation was 48.5±5.1%. Conclusions— Combined mitral and tricuspid valve repair in rheumatic disease showed satisfactory early results. Long-term results were poor because of high mortality and a high number of valve-related reoperations. The use of prosthetic ring annuloplasty was significantly associated with a reduced incidence of both mitral and tricuspid valve reoperations.

Repair of Rheumatic Tricuspid Valve Disease: Predictors of Very Long-Term Mortality and Reoperation

BACKGROUND We examined predictors of reoperation and late mortality in patients undergoing tricuspid valve repair for rheumatic disease. METHODS Between 1997 and 2007, 299 consecutive patients (mean age 50.8 + or - 13.7 years) underwent surgical repair of the tricuspid valve for multivalvular organic rheumatic disease. A total of 184 patients was found to have mitral and tricuspid valve disease, 108 triple valve disease, 5 isolated tricuspid lesion, and 2 aortic and tricuspid valve disease. Prosthetic ring annuloplasty was performed in 78 patients, commissurotomy and ring annuloplasty in 82, isolated commissurotomy in 10, suture annuloplasty in 105, and commissurotomy and suture annuloplasty in 24. RESULTS Thirty-day mortality was 7.4%. Previous valve surgery and reoperation for bleeding were risk factors for early death. Late mortality was 51.2%, in the majority of patients due to cardiac causes. There was a median follow-up of 16.4 years (range, 6 months to 34 years) and cumulative follow-up of 5,432 patients per year (96.7% complete). Age, New York Heart Association functional class IV and postclamping time were predictive factors for late mortality. At 25 years, the Kaplan-Meier survival was 26.6% + or - 4.2%. A total of 106 patients required valve reoperation. Age older than 40 years was a protective factor for reoperation. At 25 years, Kaplan-Meier freedom from reoperation was 35.0% + or - 5.3%. CONCLUSIONS Repair of the tricuspid valve in patients with rheumatic valve disease can be performed with acceptable early results, but progression of rheumatic disease is associated with a high incidence of valve dysfunction and mortality in the long term.

Determination of the mechanical properties of normal and calcified human mitral chordae tendineae.

The aim of the present research is to determine the influence of the calcification of human mitral valves on the mechanical properties of their marginal chordae tendineae. The study was performed on marginal chords obtained from thirteen human mitral valves, explanted at surgery, including six non-calcified, four moderately calcified and three strongly calcified valves. The mechanical response of the chords from the non-calcified and moderately calcified valves was determined by means of quasi-static tensile tests (the poor condition of the strongly calcified valves prevented them from being mechanically characterised). The material parameters that were obtained and analysed (the Youngs modulus, the secant modulus, the proportional limit stress, the ultimate strength, the strain at fracture and the density of energy stored up to maximum load) revealed noticeable differences in mechanical behaviour between the two groups of mitral chordae tendineae. Large scatter was obtained in all cases, nevertheless, considering the mean values, it was observed that the normal chords are between three and seven times stiffer or more resistant than the moderately calcified ones. On the contrary, the results obtained for the strain at fracture showed a rather different picture as, in this case, no significant differences were observed between the two families of chords. A scanning electron microscopy study was conducted in order to find out the relevant features of the calcium deposits present in the calcified chordae tendineae. In addition, the general aspects appreciated in the stress vs. strain curves were correlated with the collagen morphological evidences determined microscopically. Finally, the calcium content present in the three groups of chords was quantitatively determined through atomic absorption spectroscopy; then, the relation between the mechanical properties of normal and moderately calcified chords as a function of its calcium content was obtained. This analysis confirmed the existence of a strong correlation between calcium content and stiffness or resistance whereas the influence on the ductility seems to be negligible.

Optical coherence tomography assessment of vessel wall degradation in thoracic aortic aneurysms

Abstract. Optical coherence tomography images of human thoracic aorta from aneurysms reveal elastin disorders and smooth muscle cell alterations when visualizing the media layer of the aortic wall. These disorders can be employed as indicators for wall degradation and, therefore, become a hallmark for diagnosis of risk of aneurysm under intraoperative conditions. Two approaches are followed to evaluate this risk: the analysis of the reflectivity decay along the penetration depth and the textural analysis of a two-dimensional spatial distribution of the aortic wall backscattering. Both techniques require preprocessing stages for the identification of the air–sample interface and for the segmentation of the media layer. Results show that the alterations in the media layer of the aortic wall are better highlighted when the textural approach is considered and also agree with a semiquantitative histopathological grading that assesses the degree of wall degradation. The correlation of the co-occurrence matrix attains a sensitivity of 0.906 and specificity of 0.864 when aneurysm automatic diagnosis is evaluated with a receiver operating characteristic curve.

Identification of vessel wall degradation in ascending thoracic aortic aneurysms with OCT.

Degradation of the wall of human ascending thoracic aorta has been assessed through Optical Coherence Tomography (OCT). OCT images of the media layer of the aortic wall exhibit micro-structure degradation in case of diseased aortas from aneurysmal vessels. The OCT indicator of degradation depends on the dimension of areas of the media layer where backscattered reflectivity becomes smaller due to a disorder on the morphology of elastin, collagen and smooth muscle cells (SMCs). Efficient pre-processing of the OCT images is required to accurately extract the dimension of degraded areas after an optimized thresholding procedure. OCT results have been validated against conventional histological analysis. The OCT qualitative assessment has achieved a pair sensitivity-specificity of 100%-91.6% in low-high degradation discrimination when a threshold of 4965.88µm(2) is selected. This threshold suggests to have physiological meaning. The OCT quantitative evaluation of degradation achieves a correlation of 0.736 between the OCT indicator and the histological score. This in-vitro study can be transferred to the clinical scenario to provide an intraoperative assessment tool to guide cardiovascular surgeons in open repair interventions.

Spontaneous re-expansion of a collapsed thoracic endoprosthesis: Case report

A 43-year-old woman with a type B aortic dissection underwent insertion of a Zenith stent graft (Cook Inc, Bloomington, Ind). Chest pain developed 36 hours after the procedure. A computed tomography scan showed reopening of the false proximal lumen and almost complete device collapse. Because of hemodynamic stability and absence of signs of malperfusion, the patient was treated conservatively. A control computed tomography scan 7 days later showed full re-expansion of the endoprosthesis. This case illustrates that in extremely rare cases, spontaneous reexpansion of a collapsed thoracic endoprosthesis can occur after conservative management.

Regeneración celular cardíaca

La terapia celular con celulas madre, como estrategia para regenerar tejidos danados, es una de las areas mas prometedoras en el tratamiento de enfermedades con escasas o nulas expectativas de curacion. La insuficiencia cardiaca, principalmente de origen isquemico, es una de las enfermedades que mas se pueden beneficiar de esta estrategia. El objetivo es regenerar el musculo, reducir la apoptosis, aumentar la expresion del colageno intersticial e inducir la generacion de nuevos vasos. la terapia celular cardiaca ha sido propuesta con una gran variedad de celulas angiogenicas y miogenicas: mioblastos esqueleticos, celulas mononucleares y mesenquimales de medula osea, progenitores endoteliales circulantes, celulas derivadas del estroma de la grasa o del endometrio, celulas mesoteliales y pluripotenciales (induced pluripotent stem cells [iPS]). las indicaciones incluyen a pacientes con miocardiopatia isquemica o dilatada, enfermedad de Chagas, insuficiencia mitral isquemica y miocardiopatia diabetica. Los abordajes son quirurgicos, con inyeccion periinfarto, intracoronario y endoventricular percutaneo. Los mecanismos de accion propuestos son la reduccion del tamano de la cicatriz del infarto, el aumento de la viabilidad miocardica, la limitacion del remodelado ventricular y los efectos paracrinos. Sin embargo, los resultados clinicos muestran solo mejoras muy limitadas de la funcion sistolica y del remodelado ventricular. El desarrollo de estrategias que mejoren la supervivencia y la diferenciacion celular deben ser prioritarias, tales como el preacondicionamiento con electroestimulacion o la ingenieria tisular con el objetivo de desarrollar un miocardio bioartificial.

Use of mitral homograft to support a mechanical valve prosthesis: a feasible solution for recurrent mitral valve dysfunction.

CLINICAL SUMMARY A 54-year-old man with a diagnosis of mitroaortic endocarditis caused by methicillin-sensitive Staphylococcus epidermidis underwent mitral and aortic valve replacement (CarboMedics 31 mm and 23 mm; CarboMedics Inc, Austin, Tex) and received cloxacillin benzathine (INN cloxacillin) and gentamicin for 7 days, followed by cloxacillin for 5 weeks. Results of valve cultures and control blood cultures at 15 and 60 postoperative days were negative. Six months later, a first reoperation was performed because of endocarditis of both prostheses. An aortic homograft substituting the aortic root and a new CarboMedics prosthesis were implanted. Results of valve cultures, blood cultures with prolonged incubation, and serologic tests for Coxiella, Brucella, Mycoplasma, and Bartonella infections were negative. Combined treatment with vancomycin, gentamicin, and rifampin (INN rifampicin) for 2 weeks was administered, followed by vancomycin and rifampin for 4 weeks. Results of blood cultures were negative. Six months later, a second reoperation was needed because of dehiscence of the mitral prosthesis in the mitroaortic junction and macroscopic appearance of endocarditis. A new CarboMedics prosthesis was inserted. Vancomycin and rifampin were empirically administered during 6 weeks and gentamicin during 2 weeks. All cultures and serologic tests were unrevealing. Three months later, a third prosthetic valve replacement for infective endocarditis was performed. Results of cultures and serologic tests were negative. The patient received linezolid and rifampin for 6 weeks because of poor tolerance of vancomycin. Six months later, the patient underwent a fourth reoperation, this time for acute pulmonary edema and severe mitral

Hessian analysis for the delineation of amorphous anomalies in optical coherence tomography images of the aortic wall.

The aortic aneurysm is a disease originated mainly in the media layer of the aortic wall due to the occurrence of degraded areas of altered biological composition. These anomalous regions affect the structure and strength of the aorta artery, being their occurrence and extension proportional to the arterial vessel health. Optical Coherence Tomography (OCT) is applied to obtain cross-sectional images of the artery wall. The backscattering mechanisms in tissue make aorta images difficult to analyze due to noise and strong attenuation with penetration. The morphology of anomalies in pathological specimens is also diverse with amorphous shapes and varied dimensions, being these factors strongly related with tissue degradation and the aorta physiological condition. Hessian analysis of OCT images from aortic walls is used to assess the accurate delineation of these anomalous regions. A specific metric of the Hessian determinant is used to delineate degraded regions under blurry conditions and noise. A multiscale approach, based on an anisotropic Gaussian kernel filter, is applied to highlight and aggregate all the heterogeneity present in the aortic wall. An accuracy estimator metric has been implemented to evaluate and optimize the delineation process avoiding subjectivity. Finally, a degradation quantification score has been developed to assess aorta wall condition by OCT with validation against common histology.