Histological and Mechanical Assessment of Decellularized Porcine Biografts, and Its Biological Evaluation following Aortic Implantation during Mid-Term Follow-Up.

AIMS: Prosthetic graft infection frequently requires graft replacement. Among other options, a biological graft could serve as an alternative choice. Decellularization reduces tissue immunogenicity. Our aim was to determine an efficient decellularization method and to evaluate the decellularized porcine biografts' adaptability. METHODS: Four different protocols were implemented to decellularize porcine aortic segments (n = 4). Cell removal effectiveness and matrix structure preservation were histologically examined. Mechanical tests were performed. Decellularized porcine grafts were interpositioned in a porcine aorta. After a 6-month period, implanted samples were removed and evaluated using light and electron microscopy. RESULTS: Histological results showed complete removal of cells and preserved connective tissue fiber structure following decellularization, using sodium dodecyl sulfate and sodium azide. Pressure tests demonstrated similar compliance to fresh vessels. In 9 out of 10 cases, pigs survived the follow-up period. Graft rejection, intimal hyperplasia, reocclusion and/or aneurysm formation were not observed. Presence of host cells and neoendothelialization were microscopically confirmed. CONCLUSIONS: This decellularization protocol enables a cost-effective preparation of biological grafts featuring reduced immunogenicity. The implanted grafts did not degenerate during the 6-month follow-up period, the lack of graft rejection suggests acceptable immunological tolerance, while recipient cells migrate into, proliferate and differentiate, thus creating the possibility for further use as an optional vascular graft.

Sodium Pentosan Polysulfate Reduced Renal Ischemia-Reperfusion-Induced Oxidative Stress and Inflammatory Responses in an Experimental Animal Model.

Acute kidney injury (AKI) remains an independent risk factor for mortality and morbidity after vascular surgery (affecting the renal arteries) or aortic surgery (requiring suprarenal aortic clamping). These types of vascular surgery produce renal ischemia/reperfusion (I/R) injury, a common cause of AKI. The present studies aimed at monitoring the course of renal I/R injury at the cellular level and investigating the efficacy of long-term preoperative and single-shot intraoperative administration of sodium pentosan polysulfate (PPS) to protect renal tissue from acute I/R injury both in native and diabetic kidneys in rats. Western blot analyses of the proapoptotic (bax) and antiapoptotic (bcl-2) signaling pathways, as well as the extent of DNA damage (phospho-p53), were performed. Oxidative stress followed upon the termination of malondialdehyde, reduced glutathione, thiol group, and superoxide dismutase plasma levels. Inflammatory changes were measured by the determination of serum tumor necrosis factor-α and interleukin-1 levels. Morphological changes were detected by histological examinations. Our results showed that the long-term administration of PPS has an advantage in reducing I/R kidney injury in diabetic rats, while high-dose, single-shot parenteral administration of PPS prior to revascularization might be useful in nondiabetic rats.

Inhibition of Glutathione S-Transferase by Ethacrynic Acid Augments Ischemia-Reperfusion Damage and Apoptosis and Attenuates the Positive Effect of Ischemic Postconditioning in a Bilateral Acute Hindlimb Ischemia Rat Model.

AIMS: We studied the effects of the inhibition of the endogene antioxidant glutathione-S-transferase (GST) by ethacrynic acid (EA) on ischemia-reperfusion (IR) injury and postconditioning (PC) in the lower extremities. We aimed to examine the oxidative stress parameters (OSP), inflammatory response and activation of proapoptotic signaling proteins (PSP) after revascularization surgery. METHODS: Sixty Wistar rats were divided into 6 groups: control, IR, PC, EA-control, IR and administration of EA (IR/EA) and PC and administration of EA (PC/EA). The IR, PC, IR/EA and PC/EA groups underwent 60 min of infrarenal aortic cross-clamping. After that, PC was performed in the PC and PC/EA groups. In 3 of the groups, the animals were treated with EA (EA-control, IR/EA and PC/EA groups) as well. The ischemia was followed by 120 min of reperfusion. Blood samples and biopsy specimens were collected from the quadriceps muscle. Plasma malondialdehyde, reduced glutathione, thiol/sulfhydryl group levels, TNF-α and IL-6 concentrations and superoxide-dismutase enzyme activity were measured. RESULTS: The levels of the OSP and the inflammatory proteins were higher in the EA-administered groups. The ratio of phosphorylated PSP was higher in the EA-administered groups and the protective effect of PC did not develop. CONCLUSIONS: Inhibition of GST by EA augmented the IR damage. GST inhibition was associated with a different activation of the mitogen-activated protein kinases and the PSP, regulating these pathways in the process of apoptosis and PC.

[Cerebral hyperperfusion syndrome and blood pressure control]. / Cerebralis hyperperfusiós szindróma és vérnyomáskontroll.

INTRODUCTION: Cerebral hyperperfusion syndrome is a rare, hardly known condition, which can result in serious complications either after surgical or endovascular revascularization. Recognition of the typical triad (headache, seizure, focal neurological deficit) and the prompt radiological diagnosis (sonography, computed tomography) are crucial to achieve a favourable outcome. AIM: The aim of the authors was to select the endangered group and set up an effective therapeutic protocol based their own experience in combination with relevant literature data. METHOD: From the beginning of 2010 up to now three cases with these symptoms pursuant to the criteria of cerebral hyperperfusion syndrome have been recognized by the authors. RESULTS: Each of the three patients were treated by similar principles on intensive care unit, but the applied therapy resulted in complete remission in one patient only. CONCLUSIONS: At present there is no efficient diagnostic way to screen the endangered group, hence the only opportunity for prevention is the appropriate perioperative blood pressure control. If symptoms have developed already, urgent treatment is required.

[Dilemmas of the reconstruction of the major pelvic artery due to infectious aortic graft complication]. / A medencei veroér helyreállításának dilemmái szeptikus aortagraft esete kapcsán.

INTRODUCTION: In the pelvic region thrombendarterectomy and bypass procedures are the most commonly performed procedures to treat peripheral artery occlusive diseases with chronic, severe circulation failure caused by atherosclerosis. Biologic and synthetic grafts can also be used in bypass surgeries. Application of synthetic grafts can acutely increase the development of the infectious graft complication and its mortality is still between 70 and 75% in pelvic processes. We describe the difficulties and dilemmas of an infectious aortobifemoral graft. CASE PRESENTATION: 58-year-old female patient with right lower limb trophic ulcer underwent a DSA examination showing a bilateral iliac occlusion and aortobifemoral bypass surgery with Dacron graft implantation was performed. Re-occlusion and infection of the graft led to an in situ silver Dacron graft replacement. Due to the one-sided re-occlusion, a femoro-femoral crossover bypass surgery applying silver graft was performed. Despite the previously described procedures the infectious process got worse and autologous deep vein reconstruction was required beside the removal of the infectious synthetic grafts at the same time. DISCUSSION: There are local and extraanatomical solutions to reduce infectious graft complication. In pelvic infections bypass surgeries using autologous deep vein can show the best results. This procedure is the trustworthiest but also the most straining technique due to the extension of surgical time and increased blood loss. The proper surgical strategy should be selected on individual bases including cardiopulmonary load ability, patient age and technical/infrastructural possibilities.

[Endovascular treatment of subclavian artery pseudoaneurysm as a delayed complication after surgery for aorto-bifemoral graft infection]. / Aortobifemoralis graft gennyedés megoldásának kései szövodményeként jelentkezo subclavia álaneurysma endovascularis kezelése.

CASE REPORT: In this article we present a relatively rare vascular surgical complication and an uncommon treatment of it. In this case we used an aorto-bifemoral bypass on a patient with Leriche syndrome. The implanted Y-graft got infected and we were forced to remove it. Having inserted the abdominal aortic graft, an axillobifemoral bypass was also applied to secure the circulation of the lower limbs. However, the graft occluded later on, and 37 months after the inital surgery a rather large pseudoaneurysm developed at the origin of the graft in the right subclavian artery. Another surgical intervention was indicated to prevent embolisation, rupture and compression. Instead of the conventional surgical method (resection, interposition) we did an endovascular procedure. We removed the false aneurysm by inserting a covered stent, using catheter technique, into the right brachial artery and therefore prevented the previously mentioned complications. DISCUSSION: This minimal invasive method is very useful for high risk patients to prevent the injury of neighbouring anatomical structures in the region as well as minimize blood loss and potential complications of long term anaesthesia when open surgery is done.

Validity and Reliability of the Hungarian Version of Aberdeen Varicose Vein Questionnaire.

PURPOSE: The aim of our study was to translate the Aberdeen Varicose Vein Questionnaire (AVVQ) into Hungarian, and to investigate the validity and reliability of the Hungarian AVVQ, as well as to assess the health-related quality of life in patients with varicose veins of the leg. METHODS: 374 adults participated in this study who were divided into two groups (varicose vein, healthy). We analyzed internal consistency, convergent validity (using the 36-Item Short Form Survey, SF-36), repeatability, and intra-class correlation coefficient of the Hungarian AVVQ. Regarding discriminant validity, we determined the scores of the Hungarian AVVQ in both groups using the Mann-Whitney U-test. RESULTS: The Cronbach-alpha value was 0.890, while the correlation coefficient was R = 1.000. According to the results of the convergent validation, the scores of pain and dysfunction moderately correlated with some scores of the SF-36. The score of cosmetic appearance had a relationship with many scores of the SF-36. We registered a significant relationship between the score of extent of varicosity and some scores of the SF-36. There was significant correlation between the score of complications and numerous scores of the SF-36 (physical functioning, role limitations due to physical health, pain and general health). The score of pain and dysfunction, cosmetic appearance, extent of varicosity, complications and total score of the Hungarian AVVQ showed a significant difference between both groups. CONCLUSIONS: The Hungarian AVVQ was a reliable and a valid tool to assess the health-related quality of life among patients with varicose veins and was a useful tool to justify the further treatment of the patients.

Expression and protective role of heme oxygenase-1 in delayed myocardial preconditioning.

In the study the authors aimed to demonstrate the expression and protective effect of heme oxygenase-1 (HO-1) in the delayed preconditioning (PC) on cultured myocardiac cells. Neonatal rat cardiac myocytes were exposed to ischemic (ischemic medium [IM] for 20 min) and pharmacological (adenosine, epinephrine, opioid) PC. Twenty-four hours later cells were subjected to a simulated ischemia (SI)--culturing for 3 h in IM, followed by 2-h reperfusion in normal medium--and then lactate dehydrogenase (LDH), live/death ratio, and apoptosis were measured. For demonstrating the protective role of HO-1, its enzymatic activity was competitively inhibited by administration of zinc protoporphyrin IX (ZnPPIX), and HO-1 synthesis was blocked with HO-1 siRNA. Cells in control group were cultured under normoxic conditions. In SI group, cells underwent only an SI without PC. HO-1 expression in all of the groups was demonstrated with immunostaining. Our results showed a significant decrease of LDH release, apoptosis, and cell death in PC groups versus SI group, which has been risen in ZnPPIX- and HO-1 siRNA-treated groups. HO-1 immunostaining showed an appreciable HO-1 expression in PC groups, which was abolished with HO-1 siRNA administration, but not in ZnPPIX group. The results therefore suggest that HO-1 expression increases in both ischemic and pharmacological PC, and HO-1 has cellular protective effect against cell death and apoptosis in ischemia-reperfusion-induced oxidative injury.

Cardioprotective action of urocortin in early pre- and postconditioning.

Pre- and postconditioning are powerful endogenous adaptive phenomenon of the organism whereby different stimuli enhance the tolerance against various types of stress. Urocortin (Ucn), member of the corticotropin-releasing factor (CRF) family has potent effects on the cardiovascular system. The aim of this article was to investigate the action of Ucn on cultured cardiomyocytes in the process of pre- and postconditioning. Isolated neonatal rat ventricular myocytes were preconditioned with adenosine, simulated ischemia, and Ucn (10-min treatment followed by 10-min reperfusion/recovery). For detecting the effect of alternative types of preconditioning, necrosis enzyme (lactate dehydrogenase [LDH]) release, vital staining (trypan blue), and ratio of apoptosis/necrosis were examined after cardiac cells were exposed to 3-h sustained ischemia and 2-h reperfusion. Same parameters were measured in the postconditioned groups (30- or 60-min ischemia followed by postconditioning with 10-min ischemic stimulus or Ucn and 2-h reperfusion). Cells exposed to 3-h ischemia followed by 2-h reperfusion were shown as control. Our results show that LDH release a number of trypan blue-stained dead cells and the ratio of apoptotized and necrotized cells was decreased in all preconditioned groups compared with control group. In postconditioned groups LDH content of culture medium, trypan blue-positive cardiomyocytes, and the rate of apoptotic/necrotic cells was reduced contrasted with non-postconditioned group. We can conclude that preconditioning with Ucn induced such a powerful cell protective effect as adenosine and ischemia. Furthermore, postconditioning with Ucn after 60-min ischemia was more cardioprotective than ischemic postconditioning.

[Pathology and diagnostic opportunities of lower limb compartment syndrome]. / Az alsó végtagi compartment-syndroma kórtana és diagnosztikai lehetoségei.

BACKGROUND: The indication for the surgical treatment of lower limb compartment syndrome mostly depends on the clinical signs, which can be uncertain and often delayed, resulting in a late and insufficient intervention. AIM: In this study, the progression of compartment syndrome was monitored with the measurement of intracompartmental pressure and tissue oxygen saturation. MATERIALS AND METHODS: 16 patients (12 male and 4 female; mean age: 62,7 years) underwent acute lower limb revascularization surgery due to critical (more than 4 hour) limb ischaemia. The indications were the following: 5 iliac artery embolisms and 11 femoral artery occlusions. After revascularization, significant lower limb oedema and swelling were detected. To monitor the elevated intracompartmental pressure (ICP), KODIAG pressure meter was used. Tissue oxygen saturation (StO2) was measured with near-infrared-spectroscopy. RESULTS: In 12 cases the IPC exceeded the critical 40 mmHg. In these patients, StO2 was 50-53%, in spite of the successful re-canalisation. An urgent, semi-open fasciotomy was performed in these cases. In four patients, the clinical picture suggested compartment syndrome. However, the measured parameters did not indicate surgical intervention (ICP: 25-35 mmHg, StO2: normal). SUMMARY: In addition to the empirical guidelines, we describe an evidence based surgical intervention strategy for lower limb compartment syndrome. Our results and advised parameter intervals help the clinicians to decide between conservative and operative treatment of the disease.

The role of GST polymorphism in reperfusion induced oxidative stress, inflammatory responses and clinical complications after surgical and percutaneous coronary intervention.

BACKGROUND: Patients having coronary artery disease treated by coronary bypass or PCI procedure are exposed to tissue damage because of the phenomenon called reperfusion injury. Reperfusion injury can be characterized/monitored by oxidative stress parameters, inflammatory markers and by post-operative complication rate. OBJECTIVE: Beyond the obvious factors determining its severity (affected myocardial mass, ischaemic time, collateral circulation etc.) we examined the GST enzyme group's most cardio selective member, GSTP1 and its genetic polymorphism if there is any genetically determined preventive effect on the above-mentioned parameters. MATERIALS AND METHODES: We have performed randomized prospective study in the Heart Institute of Pecs with 862 patients, treated by coronary bypass or PCI procedure. Blood samples were taken a day before, one hour, one day, one week after the operation. Leucocyte count (WBC), myeloperoxidase (MPO), thiol group (SH); Superoxide dismutase (SOD), malondialdehyde (MDA), reduced Glutathione (GSH) level was checked in different periods of time as a comparison. The onset of myocardial damage and the corresponding necro enzyme level changes were registered in the perioperative period. Our patient's GSTP1 allele pair combinations (A, B, or C) were determined by real time PCR method. RESULTS: In patients with GSTP1 AA genotype we have found significance level reaching plasma concentration rise in SOD and MDA, and drop in GSH, SH. The CKMB concentration rise in the post-operative 24 hours was significantly higher in the GSTP1 AA group. CONCLUSIONS: According to our results the AA allele combination can be considered as a risk factor. GSTP1-AA allele pair has negative effect on ischemia-reperfusion tolerance of the heart. In case of cardiovascular interventions, the study of GST enzyme polymorphisms can be an independent risk stratification factor in determining the perioperative risk in the future.

Pentoxifylline attenuates the local and systemic inflammatory response after infrarenal abdominal aortic ischemia-reperfusion.

AIMS: We studied the new anti-inflammatory effects of non-specific phosphodiesterase (PDE) inhibitor pentoxifylline (PTX) on ischaemia-reperfusion injury and postconditioning of the lower extremities. We aimed to examine the oxidative stress parameters (OSP), the inflammatory response and the changes in structure of skeletal muscle after revascularization surgery. METHODS: 50 Wistar rats in five groups underwent a 60 min infrarenal aortic cross clamping. After the ischaemia in IR+PC group ischemic postconditioning was performed, intermittent 15 seconds reperfusion, 15 seconds ischaemic periods were applied four times. The ischemic phase was followed by a 120 min of reperfusion. In IR+PTX group the animals were treated with PTX. In IR+PC+PTX group both ischemic postconditioning and PTX treatment were performed. Blood samples and biopsy from quadriceps muscle were collected. Plasma malondialdehyde, reduced glutathione, -SH-groups, TNF-alpha, IL-6 concentrations and superoxide dismutase enzyme activity were measured. RESULTS: The levels of OSP and the inflammatory proteins were significantly higher in the IR group. PTX treatment and PC could significantly decrease the levels of OSP and inflammatory proteins. When the animals were co-treated with PTX and PC the results were even better. CONCLUSIONS: Inhibition of PDE by PTX could markedly decrease the inflammatory response and moderate the ischaemia-reperfusion damages after lower limb ischemia and reperfusion. Administration of PTX could potentiate the beneficial effects of PC.

[Alternative options for examination of the patency of peritoneo-venous shunts]. / A peritoneo-venosus shuntök vezetoképességének vizsgálati lehetoségei.

For the treatment of refractory ascites we use the saphenoperitoneal shunt described by Pang in 1992 approximately 2 years. This procedure eliminates the most frequent complications of the former synthetic shunts: occlusion of the collector branches and infections as well. In addition, the use of autologous vein is cost-saving. The first Hungarian publications (K. Vincze and Z. Nagy et al.) reported good results, which are confirmed also by us, after we performed 21 operations. The publications until now usually describe the technique. This intervention is now a widely accepted one. On the other hand, just a small number of papers describe the options for the examination of patency and the follow-ups. We report about the algorithm used in our department after surgery to evaluate graft patency and surgical efficacy. A method to determine the volume of ascites developed by ourselves is described. We feel that the successful application of saphenoperitoneal shunts depends on very close follow-up. Considering that no objective method to check the patency does exist, we are sure that decisions about further operations can only be made if simultaneous diverse follow-up methods are available.