Viability of Human Arterial Grafts Monitored by Comet Assay

An analytical method for studying DNA degradation by electrophoresis after cell lysis and visualization of DNA fragments with fluorescent dye, comet assay, was used to evaluate the viability of the endothelial layer of human arterial grafts with the aim of identifying the procedure that will least damage the tissue before cryopreservation. Four groups of samples were studied: cryopreserved arterial grafts that were thawed in two different ways, slowly lasting 2 hours or rapidly for approx. 7 minutes. Arterial grafts that were collected as part of multiorgan procurement with minimal warm ischemia time. Cadaveric grafts were taken as part of the autopsy, so they have a more extended period of warm ischemia. The HeadDNA (%) parameter and others commonly used parameters like TailDNA (%). TailMoment, TailLength, OliveMoment, TailMoment to characterize the comet were used to assess viability in this study. The ratio of non-decayed to decayed nuclei was determined from the values found. This ratio for cadaveric grafts was 0.63, for slowly thawed cryopreserved grafts 2.9, for rapidly thawed cryopreserved grafts 1.9, and for multi-organ procurement grafts 0.68. The results of the study confirmed the assumption that the allografts obtained from cadaveric donors are the least suitable. On the other hand, grafts obtained from multiorgan donors are better in terms of viability monitored by comet assay. Keywords: Arterial grafts, Cryopreservation, Cadaveric, Multiorgan procurement, Viability, Comet assay.

A large arteriovenous fistula steals a considerable part of systemic blood flow during veno-arterial extracorporeal circulation support in a porcine model

Background: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is one of the most frequently used mechanical circulatory support devices. Distribution of extracorporeal membrane oxygenation flow depends (similarly as the cardiac output distribution) on regional vascular resistance. Arteriovenous fistulas (AVFs), used frequently as hemodialysis access, represent a low-resistant circuit which steals part of the systemic perfusion. We tested the hypothesis that the presence of a large Arteriovenous fistulas significantly changes organ perfusion during a partial and a full Veno-arterial extracorporeal membrane oxygenation support. Methods: The protocol was performed on domestic female pigs held under general anesthesia. Cannulas for Veno-arterial extracorporeal membrane oxygenation were inserted into femoral artery and vein. The Arteriovenous fistulas was created using another two high-diameter extracorporeal membrane oxygenation cannulas inserted in the contralateral femoral artery and vein. Catheters, flow probes, flow wires and other sensors were placed for continuous monitoring of haemodynamics and organ perfusion. A stepwise increase in extracorporeal membrane oxygenation flow was considered under beating heart and ventricular fibrillation (VF) with closed and opened Arteriovenous fistulas. Results: Opening of a large Arteriovenous fistulas (blood flow ranging from 1.1 to 2.2 L/min) resulted in decrease of effective systemic blood flow by 17%-30% (p < 0.01 for all steps). This led to a significant decrease of carotid artery flow (ranging from 13% to 25% after Arteriovenous fistulas opening) following VF and under partial extracorporeal membrane oxygenation support. Cerebral tissue oxygenation measured by near infrared spectroscopy also decreased significantly in all steps. These changes occurred even with maintained perfusion pressure. Changes in coronary artery flow were driven by changes in the native cardiac output. Conclusion: A large arteriovenous fistula can completely counteract Veno-arterial extracorporeal membrane oxygenation support unless maximal extracorporeal membrane oxygenation flow is applied. Cerebral blood flow and oxygenation are mainly compromised by the effect of the Arteriovenous fistulas. These effects could influence brain function in patients with Arteriovenous fistulas on Veno-arterial extracorporeal membrane oxygenation.

Comparing the hemodynamic effect of a large arteriovenous fistula during high and low cardiac output states

Background: A large arteriovenous fistula (AVF) is a low-resistant circuit that affects organ perfusion and systemic hemodynamics even in standard conditions. The extent of its' effect in critical states has not been elucidated yet. We used norepinephrine to create systemic vasoconstriction, dobutamine to create high cardiac output, and rapid right ventricle pacing as a model of acute heart failure in a porcine model of high-flow AVF circulation. Methods: The protocol was performed on nine domestic female pigs under general anesthesia. AVF was created by connecting two high-diameter ECMO cannulas inserted in the femoral artery and vein. Continuous hemodynamic monitoring was performed throughout the protocol. Three interventions were performed-moderate dose of norepinephrine (0.25 ug/kg/min), moderate dose of dobutamine (10 ug/kg/min) and rapid right ventricle pacing to simulate low cardiac output state with mean arterial pressure under 60 mmHg. Measurements were taken with opened and closed arteriovenous fistula. Results: Continuous infusion of norepinephrine with opened AVF significantly increased mean arterial pressure (+20%) and total cardiac output (CO) (+36%), but vascular resistance remained virtually unchanged. AVF flow (Qa) rise correlated with mean arterial pressure increase (+20%; R = 0.97, p = 0.0001). Effective cardiac output increased, leading to insignificant improvement in organ perfusion. Dobutamine substantially increased cardiac output with insignificant effect on AVF flow and mean arterial pressure. Carotid artery blood flow increased significantly after dobutamine infusion by approximately 30%, coronary flow velocity increased significantly only in closed AVF state. The effective cardiac output using the heart failure model leading to decrease of carotid artery flow and worsening of brain and peripheral tissue oximetry. AVF blood flow also dropped significantly and proportionally to pressure, but Qa/CO ratio did not change. Therefore, the effective cardiac output decreased. Conclusion: In abovementioned extreme hemodynamic conditions the AVF flow was always directly proportional to systemic perfusion pressure. The ratio of shunt flow to cardiac output depended on systemic vascular resistance. These experiments highlight the detrimental role of a large AVF in these critical conditions' models.

The impact of obesity on the outcome of severe SARS-CoV-2 ARDS in a high volume ECMO centre: ECMO and corticosteroids support the obesity paradox

PURPOSE

The aim was to verify the impact of obesity on the long-term outcome of patients with severe SARS-CoV-2 ARDS.

MATERIALS AND METHODS

The retrospective study included patients admitted to the high-volume ECMO centre between March 2020 and March 2022. The impact of body mass index (BMI), co-morbidities and therapeutic measures on the short and 90-day outcomes was analysed.

RESULTS

292 patients were included, of whom 119(40.8%) were treated with veno-venous ECMO cannulated mostly (73%) in a local hospital. 58.5% were obese (64.7% on ECMO), the ECMO was most frequent in BMI > 40(49%). The ICU mortality (36.8% for obese vs 33.9% for the non-obese, p = 0.58) was related to ECMO only for the non-obese (p = 0.04). The 90-day mortalities (48.5% obese vs 45.5% non-obese, p = 0.603) of the ECMO and non-ECMO patients were not significantly influenced by BMI (p = 0.47, p = 0.771, respectively). The obesity associated risk factors for adverse outcome were age <50 (RR 2.14) and history of chronic immunosuppressive therapy (RR 2.11, p = 0.009). The higher dosage of steroids (RR 0.57, p = 0.05) associated with a better outcome.

CONCLUSIONS

The high incidence of obesity was not associated with worse short and long-term outcomes. ECMO in obese patients together with the use of steroids in the later stage of ARDS may improve survival.

Partial resection of native and prosthetic arteriovenous fistula as a treatment of late infections complications - series of case reports

INTRODUCTION

Infection of arteriovenous fistula (AV) used for hemodialysis (HD) is associated with massive bleeding, sepsis development, formation of metastatic infectious foci, and a high risk of AV loss. Urgent management of an infected AV is crucial for successful treatment and AV salvage.

CASE REPORTS

We present the use of partial resection as a successful method of dealing with late AV infection in two cases. In case 1, the resection was performed due to an infection of the native arteriovenous fistula (AVF) with two defects above the drainage vein aneurysms. In case 2, partial resection and replacement of the prosthetic arteriovenous fistula (AVG) were done due to an infection of HD puncture site. The AVs remained patent in both cases, with no further signs of infection postoperatively and, most importantly, without the need to use a temporary HD catheter.

CONCLUSION

The establishment of a new AV is limited by the quality of the venous and arterial systems. All surgical, interventional and non-surgical means should be used to safely maintain the created AV patent. Provided that the requirements of an early indication are met, partial resection of the AV is the method of choice for AV infections and allows us to avoid using a permanent dialysis catheter in our patients.

Long-term experience with implantable treprostinil pumps in pulmonary arterial hypertension

OBJECTIVES

To compare clinical parameters and quality of life in patients with pulmonary arterial hypertension (PAH) at the time of diagnosis, at the time of LenusPro pump implantation and during intravenous treptostinil treatment.

METHODS

Seven patients with severe PAH treated with intravenous treptostinil via implantable LenusPro pumps were evaluated, including NYHA classification, six‑minute walking test, BNP and quality of life assessment using the EQ-5D-5L questionnaire before and after pump implantation.

RESULTS

No significant changes were observed in NYHA class and six‑minute walking distance test. There was however a significant improvement in the quality of life and a decrease in BNP levels. The mean EQ-5D-5L index assessed during subcutaneous treptostinil treatment was significantly worse when compared to that assessed during its intravenous application (0.39 ± 0.24 vs 0.78 ± 0.28, p ˂ 0.05); the same is true about the pain/discomfort dimension. Complications occurred, namely one nonfatal pneumothorax, one nonfatal hemothorax, and one event of nonfatal treptostinil intoxication after refilling.

CONCLUSIONS

In patients who do not tolerate subcutaneous treptostinil treatment, the use of the LenusPro implantable pump results in a significant improvement in quality of life with an acceptable safety profile (Tab. 2, Fig. 2, Ref. 19).

The influence of purification of carp collagen used in a novel composite graft with sandwich construction of the wall on its biological properties and graft patency rates

We compared graft outcome between two types of a novel composite three-layer carp-collagen-coated vascular graft in low-flow conditions in a sheep model. Collagen in group A underwent more cycles of purification than in group B in order to increase the ratio between collagen and residual fat. The grafts were implanted end-to-side in both carotid arteries in sheep (14 grafts in 7 sheep in group A, 18 grafts in 9 sheep in group B) and artificially stenosed on the right side. The flow in the grafts in group A decreased from 297±118 ml/min to 158±159 ml/min (p=0.041) after placement of the artificial stenosis in group A, and from 330±164ml/min to 97±29 ml/min (p=0.0052) in group B (p=0.27 between the groups). From the five surviving animals in group A, both grafts occluded in one animal 3 and 14 days after implantation. In group B, from the six surviving animals, only one graft on the left side remained patent (p=0.0017). Histology showed degradation of the intimal layer in the center with endothelization from the periphery in group A and formation of thick fibrous intimal layer in group B. We conclude that the ratio between collagen and lipid content in the novel three-layer graft plays a critical role in its patency and structural changes in vivo.

Development of vascular substitutes for low-flow peripheral bypass grafting - a review

The development of a low-flow vascular prosthesis is a very topical issue. The authors present a pathway for the development of a prosthesis with optimal properties based on the idea of mimicking the characteristics of a biological model (saphenous vein graft) and programming these properties in the model of the prosthetic substitute. The vascular prosthesis presented consists of three layers - a non-absorbable scaffold representing vascular &#8220;media&#8221;, and two absorbable collagen layers - pseudointima and pseudoadventitia. The basic methods of physical testing are presented - the single axis stretch test and inflation-extension test, as well as other procedures that affect the final properties. These include collagen curing, antithrombotic treatment of the inner layer and the use of sterilization methods. The designed new graft was successfully implanted in an ovine model.

Natural remodeling of the distal anastomosis of an above-knee femoropopliteal bypass depicted by CT angiography of lower limbs improves geometry of the reconstruction

The geometry of the distal anastomosis of a femoropopliteal bypass influences local hemodynamics and formation of intimal hyperplasia. We hypothesized that the distal anastomosis of an above-knee femoropopliteal bypass undergoes remodeling that results in displacement of the original course of the popliteal artery and change in the anastomosis angle. We identified 43 CT angiography examination with proximal femoropopliteal bypass and either a preserved contralateral popliteal artery or previous CTA before construction of the bypass for comparison. In these examinations, we measured the displacement distance and angle at the level of the distal anastomosis and compared these measurements with clinical and imaging data. The displacement distance was 8.8+/-4.9 mm (P<0.0001) and the displacement angle was -1° (IQR=44°). The angle between the inflow and outflow artery was 153+/-16° (P<0.0001). There was a negative association between the displacement angle and the angle between the bypass and the outflow artery (r=-0.318, P=0.037). Patients with reversed venous grafts had a greater displacement of the anastomosis (14.7+/-3.0 mm) than patients with prosthetic grafts (8.0+/-4.5 mm, P=0.0011). We conclude that construction of a distal anastomosis of proximal femoropopliteal bypass results in displacement of the original course of the popliteal artery towards the bypass and this effect is more pronounced in reversed venous grafts.

Branched pedal bypass in the treatment of critical limb ischemia - a single center experience

INTRODUCTION

Pedal bypass is a therapeutic option for limb salvage in critical limb ischemia.

METHOD

Retrospective analysis of 20 patients who underwent either simple (14 patients) or branched (6 patients) pedal bypass in a single center and had at least one postoperative follow-up. In patients with branched pedal bypass, the main trunk was connected to the pedal artery of better quality and the side branch to an artery on the opposite side of the foot. The main trunk was constructed as a reverse saphenous bypass in all patients with branched bypass. From patients with simple bypass, nine had reverse saphenous graft, three had an allograft, one patient had in situ saphenous graft, and one PTFE prosthesis.

RESULTS

The difference in the operation time was not significant. One patient with simple bypass required reoperation for wound bleeding and there was one case of perioperative mortality in the same group. The difference between the groups in the primary or secondary patency rates, limb salvage and overall survival was not significant.

CONCLUSIONS

We did not find any significant difference in patency rates, limb salvage, or perioperative complications between patients with simple and branched pedal bypass in our cohort. We believe that the anticipated benefits of constructing an additional branch are masked by the disadvantageous presence of an additional anastomosis. Adoption of a branched pedal bypass may therefore require further improvements - perhaps the utilization of a branched saphenous graft. Key words:  critical limb ischemia - peripheral arterial disease - bypass - revascularization - amputation.

Dunbar syndrome - single-center experience with surgical treatment

INTRODUCTION

Dunbar syndrome is caused by compression of the truncus coeliacus (TC), most commonly by the median arcuate ligament. Chronic irritation of the TC during breathing leads to fibrous changes of the arterial wall and formation of fixed stenosis. This compression syndrome is often associated with specific complaints including weight loss and early postprandial epigastric pain. In this study, we summarize our experience with a group of 14 patients from a single institution.

METHODS

In 14 patients who were diagnosed with Dunbar syndrome and who were referred for surgery, we performed an invasive measurement of systemic pressure in a. radialis during the operation and compared it with invasively measured pressure in a. gastrica sinistra before and after the release of TC. In patients with significant stenosis (pressure gradient above 15 mmHg), a bypass was performed.

RESULTS

The initial pressure gradient of 56±19 mmHg decreased after the release of TC to 39±16 mmHg (p.

[Combined endovascular and surgical therapy for chronic pelvic venous closure accompanied by massive prepubic and limbs varices]

We report a successful surgical and endovascular procedure in a patient with increasing chronic varicose veins resulting from a chronic post-traumatic closure of the left pelvic vein. The endovascular intervention involves an effective and fast part of the procedure dealing with the primary cause of the patients pathology with subsequent surgical treatment, which radically eliminates the secondary developing pathology of massive prepubic and convoluted varicose veins in limbs.

Postinfarction Ventricular Septal Rupture – A Rare Complication Remains Challenge for Cardiac Surgical Team

The incidence of post infarction ventricular septal rupture (PIVSR) is decreasing in the last years due to aggressive treatment of myocardial infarction with early percutaneous coronary interventions. As a consequence patients with PIVSR are referred to surgery more often with significant heart failure. The aim of this retrospective study was to assess the influence of these on the operative results and to identify the risk factors of operative mortality. A retrospective analysis of prospectively collected data of patients with the PIVSR admitted to our center from November 2004 to February 2012 was performed. Variables were analyzed using two-dimensional correspondence analysis. There were 25 patients (12 males and 13 females) with mean age 70.2 years (47–82) operated on; 17 (68%) presented with anterior and 8 (32%) with posterior PIVSR. Eighteen patients (72%) had acute heart failure, 13 (52%) presented with cardiogenic shock. Before surgery, intraaortic balloon pump (IABP) had 20 (80%) patients; in 4 (16%) a ventricular assist device was used, either Extracorporeal Membrane Oxygenation (ECMO) or centrifugal pumps as biventricular assist. Operative mortality was 40% (10 pts.). Four patients (12%) had small non-significant recurrent shunt on postoperative echocardiography. Although majority of patients with PIVSR have significant heart failure prior to surgery the operative mortality remains comparable to older studies. Predictors of perioperative death were concomitant surgical reconstruction of the left ventricle, renal impairment before operation, male gender, history of coronary artery disease, PIVSR location posterior, and shock at surgery.

Gastrointestinal complications after cardiac surgery : eight years experience in a single center

BACKGROUND

The aim of this study was to evaluate the frequency of gastrointestinal complications (GICs) and associated risk factors in patients after cardiac surgery, and to stratify them according to the risk of developing GICs in order to improve our diagnostic protocols.

METHODS

A total of 5959 patients who underwent cardiac surgery within a period of 97 months were retrospectively evaluated. Surgical procedures included coronary artery bypass grafting, heart valve surgery, aortic surgery, surgical correction of adult congenital heart defects, or combined procedures.

RESULTS

The frequency of GICs was 1.3% (75 patients). Intestinal ischemia and upper or lower gastrointestinal bleeding were the most common GICs. From 27 patients affected by intestinal ischemia, 21 patients were previously treated with intra-aortic balloon pump (p < 0.001). Low cardiac output, renal failure or dysfunction, renal risk, peripheral arterial disease, history of myocardial infarction, male gender, intra-aortic balloon pump, cardiopulmonary bypass time, aortic cross-clamp time, duration of intubation, SIRS, and MODS were associated with significantly increased risk of GICs.

CONCLUSIONS

To decrease the occurrence of intestinal ischemia, we suggest that placement of intra-aortic balloon pump should be preceded by examination of the descending aorta to rule out severe atherosclerotic changes, in which case -alternative cardiac support should be attempted.

[Complex surgical management of hemodialysis vascular access infection caused by Clostridium perfringens]

Infection of prosthetic hemodialysis (HD) shunts is one of the most common complications of vascular access in hemodialysis patients. The incidence of anaerobic infection is very rare. In such a case, management of treatment represents a great challenge for the surgeon. We report a complicated case of autologous hemodialysis shunt infected by Clostridium perfringens on the right forearm in a polymorbid female patient with chronic renal failure and myelodysplastic syndrome. The patient has undergone repeated establishment of HD shunt with subsequent polybacterial local infectious complications. Destructive clostridial infection developed at the site of the infectious complications. This very rare complication involving infection by an atypical bacterial agent requires rapid diagnosis and comprehensive multimodal treatment including surgical, antibiotic and supportive therapy. Clinical implications and optimal therapy is not precisely defined in these cases.

Endoscopic versus mini-invasive radial artery graft harvesting for purposes of aortocoronary bypass

The aim of the study was to compare three different methods of radial artery harvesting with regard to postoperative complications and perioperative stress of the patient. A total of 60 patients admitted for coronary artery bypass surgery were randomized into three groups. Each patient underwent extraction of radial artery, all performed by a single surgeon. The radial artery was harvested by one of the following three techniques: classical technique (20 patients), mini-invasive technique (20), and endoscopic technique (20). The time required for the graft harvest was greater in the group where the endoscopic technique was used (52.6 ± 11.3 min) than with the mini-invasive (41.5 ± 7.3 min) or the classical (27.8 ± 4.6 min) technique. Postoperative blood loss into drains was higher where the classical technique was used (35.5 ± 9.4 ml) as compared to the mini-invasive (20 ± 5 ml) or the endoscopic (10 ± 7.3 ml) technique. There was no significant difference among the groups in the rate of local neurological complications, contusion of wound edge, edema of the extremity, or wound infection rate. We observed no case of ischemia of the extremity, and a single case of postoperative myocardial ischemia in the group where the classical technique was used. From a clinical point of view, the mini-invasive and the endoscopic approach are comparable, but the latter is more expensive. Both mini-invasive and endoscopic techniques prolong the operation, reduce perioperative blood loss, and require additional training time.

Thrombophilia and pulmonary endarterectomy

In the present study, we compared groups of patients with and without thrombophilia, who underwent pulmonary endarterectomy (PEA), definitive treatment for chronic pulmonary hypertension resulting from thromboembolic disease.

METHODS AND PATIENTS

Between September 2004 and June 2007, we operated 54 patients with CTEPH. We divided our patients into three groups. Group I patients, had one or more signs of serious thrombophilia (15 patients), Group II patients, had no signs of thrombophilia (23 patients without thrombophilia and without Methylenetetrahydrofolate Reductase (MTHFR)), and Group III patients with MTHFR (16 patients with MTHFR only, without any serious thrombophilia).

RESULTS

After the surgery, there was a statistically considerable improvement of hemodynamic parameters (mPA, CI, PVR) in all groups, without a statistical difference between the groups. Comparison of all these groups showed more complications in-group I (thrombophilia), in particular reperfusion oedema, pericardial effusion, and renal insufficiency. Within one month, there was a considerable improvement or normalisation of haemodynamic parameters, an increase in walking distance at the six-minute walking test, and NYHA classification with no significant difference between the three groups.

CONCLUSIONS

Early hemodynamic results of patients with thrombophilia after PEA, were comparable to the results of patients without thrombophilia, when we looked at both clinical and hemodynamic improvements. We did not find any differences when we looked at the results between Group II and Group III (MTHF), when we considered the number and type of complications. Patients with thrombophilia in Group I had statistically higher morbidity, especially when it came to a higher number of reperfusion oedema, pericardial effusion, and renal insufficiency.

Dissection of thoracic aorta. Combined surgical and endovascular treatment

In our case report, we would like to present combined surgical and endovascular treatment of type A aortic dissection as a modern and definite solution of this life-threatening disease.

Particle image velocimetry measurement in the model of vascular anastomosis

Neointimal hyperplasia is the most common complication of all forms of arterial reconstructions. This response of the vascular wall to injury is influenced by many factors, especially, but not limited to, by the hemodynamic profile in the area of vascular anastomosis and in its close proximity. To eliminate this negative influence of hemodynamics on progression of neointimal hyperplasia, we tried to develop anastomosis with optimal hemodynamic parameters. In our experimental study we used Particle Image Velocimetry measurement and 3D blood flow simulation for studying flow characteristics for different length and angles of anastomoses. Based on our experimental studies and numerical simulations we believe that anastomosis with smaller angle demonstrates better hemodynamic parameters, optimal angle being less than 30 dg. Length of anastomosis in this smaller angle anastomosis is app. 2-2.5 of native vessel diameter.

Implementation of a New Programme for the Surgical Treatment of CTEPH in the Czech Republic - Pulmonary Endarterectomy

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) in indicated cases can be successfully cured by endartectomy of pulmonary arteries (PEA). Symptomatic nontreated CTEPH has a very poor prognosis; the five-year survival rate in patients with a medium pressure of over 50 mmHg in the main pulmonary artery is as low as 10 %. This kind of operation was previously not available in the Czech Republic. In 2004, a PEA programme was launched at the Cardiocentre of the General Teaching Hospital in Prague in co-operation with the institution of a well known specialist in this field (Prof. Mayer, Johannes Gutenberg University in Mainz, Germany).

PATIENTS

Between September 2004 and January 2006, 21 patients (14 males and 7 females; average age 48 years) with CTEPH were operated on, after a complex investigation. The mean pressure in the main pulmonary artery in these patients was 54.8 mmHg; 7 patients suffered from coagulopathy.

METHOD

The new surgical technique, modifications of which are used at most facilities, was developed by Jamieson and Daily at the University of California in San Diego: an arrest of circulation in deep hypothermia to protect the brain is vital for the visualisation of distal branches of the pulmonary artery.

RESULTS

21 patients were operated on with a mortality of 4.76 % (1 patient died). Other surgeries performed were suture of a defect of the atrial septum (three times), aortocoronary bypass (three times), and cryoablation of the right atrium for flutter (once). The average circulatory arrest time was 42 minutes, the average total pumping time was 331 minutes, and the average total duration of an operation was 450 minutes; the average duration of mechanical ventilation was 58 hours. Within one month there was a considerable improvement or normalisation of haemodynamic parameters and an increase in the average walking distance on the six-minute walking test by 132 metres.

CONCLUSIONS

PEA is a curative method for patients with CTEPH with a surgically accessible obstruction of the pulmonary artery. Centralisation of the care of these patients is a rational necessity, as this enables the centre to gain a maximum of experience with this complicated diagnosis and treatment. Multidisciplinary co-operation is a sine qua non for success in these programmes.

[Pulmonary endarterectomy--the surgical treatment of chronic thromboembolic pulmonary hypertension]

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) in indicated cases can be successfully treated by the endarterectomy of pulmonary arteries (PEA). Symptomatically not treated CTEPH has highly unfavourable prognosis. Five years survival of patients with mean pulmonary pressure over 50 mmHg is only 10%. PEA was not available in the Czech Republic till 2004, when PEA program was initiated it the Cardiocenter of the General teaching hospital in Prague in collaboration with leading clinics in that field (Prof. Mayer, University of Mainz, BRD).

METHODS AND RESULTS

Up-to-date surgical technique, which in various modifications has been used at majority of clinics, was elaborated by Jamieson and Daily at University of California in San Diego. It is based on reverse endarterectomy performed during complete circulatory arrest with brain protection by deep hypothermia. Till September 2005 twelve patients were operated with zero mortality. In one patient a suture of atrial septum defect was necessary to perform along. Average time of the circulatory arrest was 45 minutes; duration of the extracorporal circulation was 334 minutes. Average duration of the operation was 450 minutes. Duration of the mechanical ventilation was in average 45.5 hours. After one month already haemodynamic parameters (mPA, CI, PVR) significantly improved or normalized and the average length in the test of six minutes walking increased by 132 meters.

CONCLUSION

PEA represents a treatment method for patients with CTEPH and surgically accessible pulmonary artery obstruction. Centralized care of those patients is a rational necessity enabling to get maximum experience with complicated diagnostics and treatment of those patients. Multidisciplinary collaboration is the essential condition for the success of the program.

[Trends and results of mitral valve surgery]

BACKGROUND

Retrospective study of 303 patients with mitral valve surgery operated in the last 7 years is evaluated. A mitral valve replacement was done in 271 patients (89.4%), mitral valve reconstruction in 32 patients (10.6%). Only the replacement of mitral valve was done in 70 patients (23.1%), replacement in combination with some other intervention, most frequently the revascularization was done in 27 patients.

METHODS AND RESULTS

The total mortality in mitral valve replacements was 7.7% with the prevalence of combined surgery, including the acute cases. Mortality for patients with prosthetics was 8.6% during 1996 to 98, and only 6.5% in the following years. From patients with the mitral reconstruction four has died (12.5%), all were acute or emergent cases with combined surgery. The average length of hospitalisation was 7.5 days. Postoperative Q-IM occurred in one patient (0.41%), revision for bleeding was necessary in 16 patients (5.3%), neurological complications developed in 14 patients (4.6%).

CONCLUSIONS

Results of early mitral replacements are comparable or in some combined surgeries better to the results given in the literature or in the international register. In the aetiology of disease, a comparative decrease of rheumatic origin and an increase of ischaemic and degenerative disorders become apparent. The paper demonstrates improving results in this field of cardiosurgery, shows the new trends in the development of surgical treatment of the mitral valve and it also stresses the necessity of early indication to the surgery.

[Thoracic outlet syndrome. An atypical etiology in a typical location]

We have described a clinical case of 46 years old man suffering from TOS with non typical symptomatology. Diagnostic guidelines and possibilities of surgical treatment are discussed in this work.