Mechanical properties of mitral allografts are not reasonably influenced by cryopreservation in sheep model.

A mitral allograft is used exceptionally in the mitral, as well as in the tricuspid position, mostly as an experimental surgical procedure. The authors decided to evaluate the possibility of inserting a cryopreserved mitral allograft into the tricuspid position in a sheep experimental model. Within the framework of this experimental project the mechanical properties of the cryopreserved mitral allograft were tested. A novel methodology studying the functional unit composed of mitral annulus, leaflet, chordae tendinaea, and papillary muscle is presented. A five-parameter Maxwell model was applied to characterize the viscoelastic behavior of sheep mitral valves. A control group of 39 fresh mitral specimens and a test group of 13 cryopreserved mitral allografts from tissue bank were tested. The testing protocol consisted of six loading cycles with 1 mm elongation every 5 min. There was no significant difference in the mean values of the determined parameters (p>0.05) which confirms the main hypothesis that cryopreservation does not influence significantly material parameters characterizing the tissue mechanics. Slight discrepancy is observed in variances of viscous parameters suggesting that the values of the test group may be spread over larger interval due to the treatment.

Cryopreserved semilunar heart valve allografts: leaflet surface damage in scanning electron microscopy.

OBJECTIVE: Allograft heart valves (AHV), biological valves of human origin, offer potential advantages over conventional xenografts in terms of superior hemodynamics and, perhaps, better durability. The most important factors for long-term AHV clinical performance are the processing and cryopreservation methods. The aim of this study was to evaluate the impact of current processing protocol on valve tissue morphology, mainly to address the effect of successive processing steps on the leaflet surface structure. For the detection of fine changes in endothelial covering and underlying layers, our own modification of the scanning electron microscopy (SEM) technique was utilized. MATERIAL AND METHODS: The study was based on an investigation of 20 AHV (40 specimens). Fourteen valves came from heart-beating donors (multiorgan harvesting) when the heart could not be transplanted for any reason (donor criteria, availability of recipient and/or logistics). Six were obtained at the time of routine postmortems--non heart-beating donors (NHBD). All specimens were initially fixed in Baker's solution. Tissue samples were dissected, dried with hexamethyldisilazane (HMDS), gold-coated, studied and photographed by SEM (Tesla BS 301). In order to define the integrity of the endothelium, subendothelial layers and the quality of the surface under SEM, a special six-level score system was introduced: 1-intact endothelium, 2-confluent endothelium with structural inhomogeneity, 3-disruption of intercellular contacts, 4-separation of endothelial cells, 5-complete loss of endothelium, 6-damage of subendothelial layers). AHV samples were divided into 4 groups for comparison. One aortic AHV "fresh" control sample obtained from a heart-beating donor was evaluated without any processing and was compared with (i) tissue from AHV obtained from NHBD with warm ischemia of 12 and 48 hours, (ii) samples stored at +4 degrees C in saline for 24 h, (iii) antibiotic-treated tissue for 24 h at 37 degrees C and finally with (iv) cryopreserved valves stored in liquid nitrogen (-196 degrees C) for 6-38 months. RESULTS: Our alternative for drying samples by the HMDS method proved to be suitable for thin membranes of human semilunar valves. We were able to detect early changes in the endothelium after harvesting and denudation of the endothelial covering during preservation with and without freezing. The surface of the AHV samples revealed the typical features and score system determined endothelial cell damage. Control "fresh" sample: score 2, (i) NHBD samples with warm ischemia of 12 h: score 3-4, with warm ischemia of 48 h: score 4-5, (ii) samples stored at +4 degrees C in saline for 48 h: score 5-6, (iii) antibiotic-treated tissue for 24 h at 37 degrees C: score 5, (iv) cryopreserved valves stored in liquid nitrogen for 6-38 months: score 5-6. CONCLUSION: SEM (using HMDS drying) together with other methods may be helpful for the morphological control of processing, cryopreservation and liquid nitrogen storage of AHV. Severe AHV leaflet endothelial destruction was proven on AHV grafts. These changes arose already in the initial steps of tissue processing, just after the donor heart harvesting and then at the time of antibiotic valve graft treatment. These results are considered as the starting point for the development of a better preservation protocol.

[Resection of metastatic nondifferentiated carcinoma of sternum with thoracic wall reconstruction and simultaneous myocardial revascularization for ischemic heart disease--case report]. / Resekce sterna s rekonstrukcí hrudní steny pro metastázu nediferencovaného karcinomu v kombinaci s revaskularizací myokardu pro ischemickou chorobu srdecní--kazuistika.

Authors offer the case report of a patient with metastatic non differentiated carcinoma of sternum simultaneously suffering from ischemic heart disease. The patient underwent actinotherapy & hyperthermia followed by resection of sternum and coronary artery bypass grafting in one session. Chest wall defect was closed by means of latissimus dorsi muscle rotation. Postoperative palliative chemotherapy started 16 weeks postoperatively. Primary tumor was not found, neither preoperatively nor during the 36 months' postoperative remission.

[Simultaneous cardiac and thoracic operations]. / Simultane Herz- und Lungenoperationen.

BACKGROUND: Optimal surgical strategy in patients with combined disease of heart (mainly ischemic heart disease or critical valve disease) and other thoracic organs (mainly pulmonary carcinoma) is still controversial. METHODS: From 1997 to 2004, 13 simultaneous cardiac and thoracic operations were performed in 13 patients. Most of them were necessary for combinations of symptomatic coronary artery disease (CAD) and bronchogenic carcinoma (BCA). PATIENT CHARACTERISTICS: 11 patients showed CAD, mean preoperative LVEF was 44 %. SURGICAL PROCEDURE: Surgical exposure was performed via sternotomy in 10 patients, the rest of the patients underwent thoracotomy. Seven patients were operated on cardiopulmonary bypass, the others underwent an off-pump procedure. Eleven patients underwent CABG, mean number of anastomoses were 2.1 (range 1-4), two patients underwent aortic valve replacement. One patient underwent radical removal of pulmonary adenocarcinoma with local expansion into the left atrium. For the lung cancer lobectomy was necessary in 8, pneumectomy in 1, extirpation of multiple metastases in 1, resection of the trachea in 1 patient. Histological diagnosis was epidermoid carcinoma in 6, adenocarcinoma in 3, undifferentiated carcinoma in 1, metastasis of Grawitz tumor in 1, pneumoconiosis in 1 patient. RESULTS: No patient died in hospital. One patient had to be re-explored for bleeding. Mean blood loss, duration of intubation and length of hospital stay were not different from other patients who underwent cardiac operation only. CONCLUSION: In accordance with the majority of the data published in the literature, combined procedures did not negatively influence hospital morbidity and mortality. Simultaneous operations eliminate the necessity of a second operation and do not delay the postoperative oncological therapy. Long-term results are primarily determined by histological diagnosis and by the extent of the tumor.

[Resection of the trachea with extracorporeal circulation as a simultaneous procedure during coronary artery bypass grafting--a case report]. / Resekce trachey s mimotelním obehem jako simultánní výkon pri chirurgické revaskularizaci myokardu--kazuistika.

The authors describe their surgical management of a female patient with a symptomatic coronary artery disease, who had developed a postintubation stenosis of the trachea. The patient sufferred from a rest dyspnoea with stridor. The unusual combination of the both cardiac and tracheal disorders were managed employing a one-step cardio-thoracic surgical procedure. The tracheal resection was conducted in the extracorporeal circulation condition together with the myocardial revascularization. The case shows how, in indicated cases, availability of the extracorporeal circulation can widen a spectrum and limits of the standard chest surgery.

[Ischemic mitral regurgitation. Clinical review emphasizing the surgical treatment]. / Ischemická mitrální regurgitace Klinické review s durazem na chirurgickou lécbu.

Ischemic mitral regurgitation represents comparatively frequent complication of the myocardial infarction. Presence of the ischemic mitral regurgitation has a negative effect on the immediate mortality after the myocardial infarction and on the long-term survival. Ischemic mitral regurgitation is a functional, not structural impairment of the mitral valve and it is caused by altered geometry of the left ventricle. The article deals with the development and pathophysiology namely of the chronic ischemic mitral regurgitation and with the contemporary potential of surgical treatment of that serious complication of the ischemic heart disease.