One-year results from cryopreserved mitral allograft transplantation into the tricuspid position in a sheep experimental model.

Mitral allografts are still used only exceptionally in the mitral or tricuspid position. The main indication remains infectious endocarditis of atrioventricular valves for its flexibility and low risk of infection. The aim of our study was to evaluate 1-year results of mitral allografts transplantation into the tricuspid position in a sheep model. Mitral allografts were processed, cryopreserved, and transplanted into the tricuspid position anatomically (Group I - 11 animals) or antianatomically (Group II - 8 animals). All survivors (4 from Group I, and 3 from Group II) were checked at 3, 6, and 12 months by echocardiography with the exception of one survivor from Group II (which was examinated only visually). Examination throughout follow-up included for mitral allograft regurgitation and annuli dilatation. At postmortem, the papillary muscles were healed and firmly anchored to the right ventricular wall in all subjects. Transventricular fixation of the papillary muscles with buttressed sutures was proven to be a stable, reproducible, and safe method for anchoring mitral allograft leaflets. There were no significant differences between the two implantation methods. Annulus support of mitral allografts might be very useful in this type of operation and could prevent annular dilatation.

[Recurrent prosthetic endocarditis in a 21-year old patient with renal transplantation treated with allogeneic homograft]. / Recidivujúca protetická endokarditída u 21-rocného pacienta s transplantovanou oblickou riesená alogénnym homograftom.

Prosthetic infective endocarditis is a possible complication of implantation of a prosthetic cardiac valve. Without early and effective treatment, it can have fatal consequences. One treatment option is use of an allogeneic cryopreserved homograft. This case report presents a 21-year old patient after kidney transplantation due to hereditary nephrotic syndrome and aortic valve replacement with aortic conduits. After fever was noted in the patient, prosthetic infective endocarditis was diagnosed by echocardiography and also confirmed by CT-3D examination. The cryopreserved aortic homograft was implanted at the Department of Cardiac Surgery. This along with additional conservative management effectively treated the infection. Based on literature data and our own experience, we believe that the treatment of prosthetic endocarditis after aortic valve replacement with cryopreserved homograft can be a method of choice.

[An overview of the results of renal transplantation in the Czech Republic]. / Piehled výsledku transplantací ledvin v Ceské republice.

Renal (kidney) transplantation is now a routine and the most successful form of renal replacement therapy. There is a long tradition of renal transplantation in the Czech Republic, The first was performed as early as 1961 in Hradec Kralove, and the programme as such was launched in 1966 with the first successful transplantation at the Institute of Experimental Surgery (later Institute for Clinical and Experimental Medicine, Prague). At present, transplantations are being performed at 7 transplantation centres (IKEM Prague, Centre for Cardiovascular and Transplantation Surgery Brno, Faculty Hospitals Hradec Kralove, Plzen, Olomouc and Ostrava and Faculty Hospital Motol for children). From the programme launch until the end of 2010, 8,761 renal transplantations were performed, 364 in 2010 alone. One-year patient and cadaver renal allograft survival, transplanted in the CR between 2000 and 2009, is around 95% and 92%, respectively, and 5-year survival is 87% and 81%, respectively. As of 31st December 2009, a total of 3,771 patients lived with functional renal allograft in the Czech Republic and the proportion of patients with irreversible renal failure treated with transplantation has recently been around 40%.

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.

[Midterm results aortic valve replacement with allograft]. / Strednedobé výsledky implantací aortálního alograftu.

INTRODUCTION: Aortic allograft implantation into the aortic position in adults is standard procedure with some controversary. The most popular indication is bacterial endocarditis. We would like to present our midterm results. RESULTS: We implanted 61 allografts in 60 patients (between 10/2002 and 04/2008). Men were 46 (76.8%) and average age was 57 +/- 10.76 year. 30 days mortality was 9 people (15.0%, all with bacterial endocarditis). Late mortality 1 man (1.6%). Follow up 1-66 months, average 39.18 SD +/- 14.3 months, median 42 months. CONCLUSION: Implantation of aortic allograft into the aortic position is standard procedure with good midterm results. Relative high early mortality is dependent on preoperative status in patiens with acute bacterial endocarditis--all early death people were people with acute bacterial endocarditis and minimally one vital organ severe dysfunction.

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.

[Aortic allograft (homograft) for the treatment of valvular disorders in adults with focus on treatment of infective aortic valve endocarditis]. / Aortální alograft (homograft) v lécbe chlopennich srdecních vad dospelých s durazem na lécbu infekiní endokarditidy aortální chlopne.

Still after 40 years of heart valve prostheses intensive development ideal valve substitute still does not exist. Aortic allograft represents one alternative which could be used for aortic and/or pulmonary valve replacement. This type of biological heart valve prosthesis is being currently discussed from the point of view of Tissue Banking, as well as from clinical aspects--e.g. surgical implantation technique and long term results. Live issue remains particularly the aortic allograft implantation into the aortic position. The authors discuss the aortic allograft role in the aortic valve infectious endocarditis treatment, which was widespread worldwide and accepted. Aortic allograft implantation is considered as a method of choice in that particular indication, especially in prosthetic aortic valve endocarditis and in left ventricle outlet tract destruction cases. The method is considered to be more technically demanding than routine heart valve surgery (heart valve replacement by means of mechanical or commercial biological prostheses), but literary and authors own experience in that particular group of patients looks encouraging. Aortic allografts permanent supply in our country is secured.

Allograft semilunar cardiac valves processing and cryopreservation - morphology in scanning electron microscope.

OBJECTIVE: The most important factors of long term clinical performance of biological heart valve prostheses are methods of processing and cryopreservation. That is why we decided to evaluate the impact of current Allograft Heart Valves (AHV) Bank protocol on valve tissue morphology. Scanning electron microscope (SEM) is a valuable tool for investigation of biological surfaces. In case of cardiac valves it is especially suitable for detection of fine changes in endothelial covering and underlying layers. MATERIAL AND METHODS: "Fresh" aortic and pulmonary AHV samples, harvested from "heart-beating" cadaveric donors, were compared with (1) tissue from AHV obtained from non heart-beating donors, (2) samples stored in 4 degrees C saline for 24 h, (3) antibiotic treated tissue for 24 h at 37 degrees C and finally (4) cryopreserved valves, stored in liquid nitrogen (-196 degrees C) for 6-38 months. All samples were dissected, dried with hexamethyldisilazane (HMDS), gold coated, studied and photographed by SEM (Tesla BS 301). RESULTS: Our alternative method of 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. CONCLUSION: SEM (using HMDS drying) along with other methods may be helpful for the morphological control of processing, cryopreservation and liquid nitrogen storage of AHV. According to the current findings we have to avoid washing of AHV in saline after harvesting.

[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.

Implantation of cryopreserved mitral allograft into the tricuspid position in an experimental study in sheep: technical aspects of implantation and immediate results evaluated by epicardial echocardiography.

AIMS: Cryopreserved mitral allograft valve (MAV) offers theoretical advantages over conventional mechanical or biological prostheses in tricuspid position, especially in infectious endocarditis patients. MAV processing and tricuspid valve (TV) replacement in a sheep model is described. METHODS AND RESULTS: In 20 adult sheep, MAV were harvested, processed and cryopreserved. One month later, recipient's TV were excised and the MAVs were transplanted into the tricuspid position in 13 sheep, under general anaesthesia, via a right thoracotomy, with an extracorporeal circulation (ECC) and cardioplegic heart arrest. Both MAV papillary muscles were anchored into the right ventricular wall by transmural stitches and the MAV anulus was sewn into the recipient's tricuspid anulus. After weaning from ECC, the anatomy and function of the MAV in the tricuspid position was assessed by epicardial echocardiography. The average duration of the ECC was 58 minutes (42-88), the cardioplegic heart arrest was 36 minutes (28-45). Weaning from EEC was always uneventful. Right atrial & pulmonary artery pressure measurements and epicardial echocardiography documented good function of all MAVs. CONCLUSION: MAV remained mechanically strong enough for implantation into the tricuspid position. Reproducible technique of MAV transplantation into the tricuspid position with excellent early postoperative haemodynamic performance was developed.

[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.

Possibilities of using vena cava filters in pregnant women with venous thromboembolism. Case reports.

Two cases of venous thromboembolism (VTE) (26th week and 35th week of pregnancy) are described. The standard anticoagulation therapy (Fraxiparine) with vena cava (IVC) filter insertion was applied with successful result and uneventful post partial period. The indications of IVC filters (permanent x retrievable x temporary) and timing of insertion and/or extraction are discussed. IVC filters are an effective and safe method in the prophylaxis and therapy of VTE in pregnancy. This method is justified to be used for a defined group of high-risk patients where benefit predominates potential complications.

Cardiac rhabdomyosarcoma.

Cardiac sarcoma is a very rare neoplasm and is difficult to diagnose. The case of a 51-year-old man with a left atrial tumour, locally recurrent three months after its surgical removal, is presented. Computed tomography showed metastatic spread to the lung parenchyma. On revised histology, the mass extirpated was a sarcoma. Because of the metastatic spread, further therapy was symptomatic only; the patient died 15 months after the first manifestation of his problems. Immunohistochemical staining confirmed cardiac rhabdomyosarcoma with metastatic spread to the lungs. Difficulty in diagnosing and treating cardiac tumours is discussed.

[Experimental ischemic renal injury--effect of surgical technique and the protective effect of a nonpeptide angiotensin II antagonist (losartan)]. / Ischemické poskození ledvin v experimentu--vliv chirurgické techniky a protektivní úcinek nepeptidového antagonisty angiotenzinu II (losartanu).

Experimental renal ischaemic injuries are typically produced by temporary closure of the renal artery. In rats, two different methods of such temporary closure of the renal artery were compared: snaring of the artery by tourniquet, and clamping by a microsurgical bulldog clamp. The consequences of ischaemic periods 60, 90 and 120 minutes were evaluated. In different experimental series, the potential protective effect of non-peptic AT1 angiotensin II receptor antagonist losartan on postischaemic renal injury was evaluated. The seven-day survival and the degree of functional renal damage (according to the plasma levels of creatinine and urea) were analyzed 24 hours and 7 days after experimental renal ischaemia. Ischaemia, produced by the tourniquet led to a more significant renal damage than ischaemia caused by clamping of the renal artery by a microclamp (higher 7-day mortality rate, higher postischaemic plasma levels of creatinine and urea). Losartan decreased the consequences of renal ischaemia caused by the tourniquet, but did not change the outcome of renal ischaemia produced by microsurgical bulldog clamps. We found, that not only the duration of ischaemia and pharmacology, but even the surgical technique of producing renal ischaemia are important factors in experimental studies evaluating ischaemic renal damage. These findings provide evidence of the role of angiotensin II in postischaemic renal injury by a renal tourniquet. This particular mechanism is probably not involved, when renal artery is gently temporarily closed by a bulldog microclamp.

[Renal transplantation in children in the Czech Republic]. / Wyniki przeszczepiania nerek u dzieci w Republice Czeskiej.

The aim of the study is to review results of pediatric renal transplantation in center in Prague, Czech Republic. Results are compared with the registry data from Europe and United States. Patients, who underwent RTx at the University Hospital Motol, Prague (Czech Republic) between 1977 and the end of 1999, were analyzed. Since 1977 128 Rtx from cadaveric donors were performed in children in mean age 12.8 +/- 4.1 years. In 1977-1987, patients were treated with prednisone and azathioprine, and since 1988, cyclosporine A, added to prednisone and azathioprine. Sequential quadruple immunosuppression was used only in few highly sensitized patients. Acute graft rejections were treated with methylprednisolone pulses, antithymocyte globulin and monoclonal antibodies OKT3, in selected cases. In 1988 and 1999 cyclosporine A was replaced by tacrolimus as initial immunosuppression in some patients. The number of Tx ranged between 5 and 13 per year. Patients and graft survival were significantly lower in the first time period 1977-1987 with a median patients 5-year survival rate of only 50% and graft survival 30%. In the last period (1988-1999) 5-year patients survival is 90% and 5-year graft survival is 68% (p = 0.01). Two cases of posttransplant lymphoproliferative disease were diagnosed so far. One of them died several months after RTx, the other received cytostatic therapy for Hodgkin tumor and graft function was maintained. Main causes of graft failure were chronic rejection followed by acute steroid resistant rejections, severe cytomegalovirus infections, noncompliance, vascular thrombosis, and recurrence of original disease.

[Aortic reconstruction in neonates with hypoplastic left heart syndrome] . / Rekonstrukce aorty u novorozencu se syndromem hypoplastického levého srdce.

The surgical technique and tactics of the Norwood operation in neonates with hypoplastic left heart syndrome represent a surgical challenge. The Norwood operation was performed from the midline sternotomy approach, in extracorporeal circulation and deep hypothermic circulatory arrest was used for reconstruction of the hypoplastic aorta. Operation consisted of reconstruction of the "neoaorta" and the aortic arch from the original hypoplastic ascendent aorta, pulmonary trunk and a patch cut from a pulmonary homograft or pericardium, excision of the atrial septum and an arterial shunt from a Goretex vascular graft 3.5 or 4 mm in diameter. In patients with well developed aortic arch it was possible to reconstruct the aorta using Damus-Kaye-Stansel operation without circulatory arrest. Out of 12 operated patients with this defect, two (16.7%) died during the early postoperative period, one patient died late. The postoperative course was often complicated. In 6 (50.0%) patients the second step of Norwood operation, the bidirectional cavopulmonary anastomosis, was performed without mortality. According to our experience, it was necessary to prepare patients adequately before the first surgery. Perfect reconstruction of the aorta and a well functioning shunt had the crucial significance.

[The first sequential transplantation of both lungs in the Czech Republic]. / První sequencní transplantace obou plic v CR.

The authors describe the case of the first sequence transplantation of both lungs in the CR. This operation is indicated in all patients suitable for transplantation of the lungs who suffer from chronic pulmonary infection.