Identification of Human Pathological Mitral Chordae Tendineae Using Polarization-sensitive Optical Coherence Tomography.

Defects of the mitral valve complex imply heart malfunction. The chordae tendineae (CTs) are tendinous strands connecting the mitral and tricuspid valve leaflets to the papillary muscles. These CTs are composed of organized, wavy collagen bundles, making them a strongly birefringent material. Disorder of the collagen structure due to different diseases (rheumatic, degenerative) implies the loss or reduction of tissue birefringence able to be characterized with Polarization Sensitive Optical Coherence Tomography (PS-OCT). PS-OCT is used to discriminate healthy from diseased chords, as the latter must be excised and replaced in clinical conventional interventions. PS-OCT allows to quantify birefringence reduction in human CTs affected by degenerative and rheumatic pathologies. This tissue optical property is proposed as a diagnostic marker for the identification of degradation of tendinous chords to guide intraoperative mitral valve surgery.

Daptomycin treatment in Gram-positive vascular graft infections.

BACKGROUND: Daptomycin is a bactericidal antibiotic approved for the treatment of skin and soft tissue infections and right-side endocarditis. However, there is a lack of published data outlining its usefulness in vascular graft infections (VGI). The aim of this study was to describe the clinical experience of daptomycin use in the treatment of VGI caused by Gram-positive bacteria. METHODS: This was a retrospective cohort study of patients diagnosed with VGI receiving daptomycin at a tertiary care hospital during the period January 2010 to December 2012. RESULTS: Of a total 1066 consecutive patients who had undergone vascular grafts (VG), 25 were diagnosed with VGI. Fifteen of these patients (11 prosthetic VG, three autologous VG, one both types) received daptomycin (median dose 6.7mg/kg/day, range 4.1-7.1mg/kg/day; median age 69 years, range 45-83 years; 80% male). The infected bypass was removed in 13 cases. The most common reason for selecting daptomycin was kidney failure (53%). The Gram-positive organisms isolated were coagulase-negative Staphylococcus (n=10), Staphylococcus aureus (n=3) (two methicillin-resistant S. aureus), Enterococcus faecium (n=2), and Enterococcus faecalis (n=1). The mean follow-up was 69 months (interquartile range 48-72 months). Ten patients (66.7%) achieved complete healing of the VGI. A recurrence of the infection was observed in 100% of patients in whom the bypass was not removed. Among patients who did not achieve complete healing, one needed a supracondylar amputation and one died as a consequence of infection. Five patients received treatment with rifampicin in addition to daptomycin and they were all cured. CONCLUSIONS: The use of daptomycin and surgery for Gram-positive VGI was effective and well tolerated, and this may be a good alternative for the treatment of VGI in patients with peripheral arterial disease in whom renal insufficiency is common.

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.

Infestation of a diabetic foot by Wohlfahrtia magnifica.

Myiasis is the infestation of animals or humans by larvae from some species of dipteran flies. Depending on the tissues invaded, the maggots of these insects can produce different diseases of the skin, or mucoses (ocular, genitourinary, and oropharyngeal). Wohlfahrtia magnifica is one of the species causing myiasis; although it is a real veterinary problem, it rarely infests humans and extraordinarily in the context we describe. We herein present the case of a diabetic patient diagnosed with class IV peripheral vascular disease (Fontaine classification) who suffered infestation by W. magnifica and the management given to this pathologic process. The patient consented to the publication of this report.

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.

A concealed atriopleural fistula resulting from a cardiac stab wound.

A young male presented with a right parasternal stab wound. The chest radiography was normal and transthoracic echocardiography ruled out pericardial tamponade. He remained hemodynamically stable until three hours later when signs of progressive anemia were observed. Chest computed tomography showed massive right-sided hemothorax. The patient underwent surgery, which revealed an active bleeding atriopleural fistula connecting the right atrium and draining into the right pleura resulting from the negative pressure generated during respiration. This mechanism prevented cardiac tamponade and maintained initial hemodynamically stability.

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

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.

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.

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.

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.

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.

Performance at 10 years of the CarboMedics "Top-Hat" valve. Postclamping time is a predictor of mortality.

OBJECTIVE: The CarboMedics "Top-Hat" supraannular prosthesis was designed to permit the implantation of a larger prosthesis. We evaluated the outcome at 10 years in patients with this prosthesis. METHODS: Between June 1993 and May 2001, 269 patients (average age, 63.9 years) received a CarboMedics "Top-Hat" supraannular aortic prosthesis. Primary valve replacement was performed on 203 patients (75.5%) and repeat valve replacement on 66 (24.5%). The duration of myocardial ischemia was 70.2+/-31.4 min, cardiopulmonary bypass 96.1+/-48.3 min, and postclamping time (time between release of aortic clamp and the end of extracorporeal circulation) 22.1+/-41.3 min. The mean follow-up was 82.3+/-17.8 months. Follow-up was 97.6% complete. RESULTS: The hospital mortality was 5.9%. It was 1% when the duration of postclamping time was <15 min, 2.8% between 15 and 29 min, 13.2% between 30 and 44 min, and 26.9% >44 min. In the multivariate analysis, postclamping time, urgent surgery, and body mass index were statistically significant risk factors for hospital mortality. The late mortality was 17.1%. Cardiac-related mortality showed a linearized rate of 18.1% per 1000 patients-year. The Kaplan-Meier estimates for cardiac-related mortality was 75.0% at 10 years. Postclamping time, aortic valve gradient, age over 70 years, and BMI were statistically significant risk factors for cardiac-related late mortality. The incidence of paravalvular leak in the "Top-Hat" aortic prosthesis was 1.7% per 1000 patients-year. CONCLUSIONS: Using the CarboMedics supraannular prosthesis allows implantation of a larger prosthesis without increasing valve-related complications. Postclamping time appears as a strong predictor of both hospital mortality and late cardiac-related death.