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.

[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.

[An overview of treatment options for a rare disease, aneurysm of the popliteal vein, in connection with a case]. / Egy ritka kórkép, a vena poplitea aneurysma kezelési lehetoségeinek áttekintése egy eset kapcsán.

INTRODUCTION: Popliteal vein aneurysm is a rare, but potentially life-threatening condition that can lead to deep vein thrombosis and/or pulmonary embolism. It is often asymptomatic, but symptoms may include pain, post-thrombotic syndrome or chronic venous insufficiency. An experienced physician may be able to detect a palpable mass in the popliteal fossa. Duplex ultrasound is the first line of diagnosis. CT or MR venography play a role in the diagnosis. OBJECTIVE: To review the international literature, explain the possible treatment options, and present our case. CASE REPORT: A 62-year-old female patient had a recurrent pulmonary embolism while on direct-acting oral anticoagulant therapy. Duplex ultrasound and MR angiography were performed and confirmed a partially thrombosed aneurysm of the right popliteal vein. Aneurysm resection and venorrhaphy were performed as treatment. At follow-up, ultrasound showed adequate flow in the deep venous system. 6 months later, the control MR angiography showed good flow without stenosis. There were no postoperative complications. Discussion and literature review: The pathomechanism of the disease remains unclear. Treatment options are conservative therapy and/or surgical intervention, but there is no consensus regarding the therapy of symptomatic or asymptomatic cases. There is no clear statement regarding the method and duration of postoperative anticoagulant therapy. CONCLUSION: In the case of recurrent pulmonary embolism, the possibility of a popliteal vein aneurysm should be considered. Ultrasound is a non-invasive, widely available initial diagnostic tool. In addition to conservative treatment, the possibility of surgical intervention can be considered. The surgical procedure described in our case was successful. Orv Hetil. 2023; 164(39): 1544-1549.

[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.

Long-term results of the treatment of Stanford type B aortic dissection with medical and invasive therapy in Hungary / Akut Stanford B típusú aortadissectio konzervatív és invazív terápiájának hosszú távú eredményei Magyarországon

Introduction and objective: Acute Stanford type B aortic dissection (ATBAD) is a potentially life-threatening condi-tion, which may require immediate intervention. This study aims to compare the short-and long-term results of medical, open surgical and endovascular management of ATBAD. Method: This is a retrospective, multi-centre cohort study, where patients admitted with acute and subacute TBAD between Jan. 2011 and Dec. 2020 were included. Results were compared between patients treated with medical, open surgical and thoracic endovascular aortic repair (TEVAR). 30-day mortality and major complications were registered. Survival and freedom from reintervention were noted. Results: A total number of 188 patients were included (69.7% man, mean age: 57 +/- 12.2 years). Hypertension was present in 88.8% of the patients. The 30-day mortality was more higher among patients who underwent open sur-gery, than among patients after TEVAR (26% and 16.7%, p = 0.12). Postoperative lung complication (22.6% and 19.4%) and vascular complication (25.9% and 16.7%) were common in both open and TEVAR groups. In the con-servatively treated group, three patients required intervention in the first 30 days (renal stent implantation: n = 2, TEVAR: n = 1). Median follow-up was 41 (IQR, 73.5) months. There was no significant difference in reoperations during follow-up between the three groups (p = 0.428). 6-year survival was significantly lower among patients with open surgery compared to the other two patient populations (54.8% vs. 79.3% and 75%, p = 0.017). Conclusion: In the invasive treatment of ATBAD, TEVAR is associated with superior short-and long-term compli-cation rate, and survival. There is no significant difference between the long-term results of medical therapy and TEVAR.

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.

[Laparoscopic devascularization of the stomach and the abdominal esophagus with the LigaSure instrument in a porcine model]. / A gyomor és az abdominális nyelocsosza- kasz laparoszkópos devaszkularizációja LigaSure eszközzel sertés modellen.

OBJECTIVES: In this study we proved the feasibility of a new minimally invasive procedure for the devascularisation of the proximal stomach and the abdominal esophagus to prevent recurrent variceal bleeding in portal hypertension in a new animal model. MATERIALS AND METHODS: Experiments were performed on 12 female pigs, in two animal groups. In the first step (I. group n=6) portal hypertension was created by controlled laparoscopic clip ligation of the portal vein. The increased portal pressure was established by the needle puncture of the portal vein and the spleen. Two weeks later, the dilated veins were sealed along the lesser and greater curvature and the transhiatal esophagus with the 10 mm LigaSure instrument. Successful of the experimental model had encouraged us to perform this method on other animals (II. group, n=6), using the 5 mm instrument. RESULTS: There was no intraoperative bleeding after using both LigaSure instruments. Autopsy (2 weeks later) showed correct placed clips with partial occlusion of the portal vein without portal vein thrombosis. There was no evidence of postoperative bleeding. Histological investigation of the gastric surface confirmed complete sealing of the extended varices. CONCLUSION: The laparoscopic LigaSure instrument was found to be safe and suitable equipment for the ligation of the dilated veins along the gastric surface and the abdominal esophagus, and this method could be an alternate choice for the patients with recurrent variceal bleeding.

[Oxidative stress and leukocyte activation after lower limb revascularization surgery]. / Alsóvégtagi revaszkularizációs mutéteket követo oxidatív stressz vizsgálata.

The authors aimed to study of oxidative stress and thrombocyte function in the perioperative interval following the revascularization surgery of lower limb. The prospective randomised study involved 10 patients whose surgical interventions were indicated by lower limb embolism, thrombosis or abdominal aorta aneurysm, and 10 healthy volunteers were also involved in the study. Peripheral blood samples were collected before, and after the surgery (2, 24 hours and one week). The maximal free radical production and lag time of the free radical production of activated leukocytes were measured, and leukocyte adhesion molecules (CD11a and CD18) signing leucocyte activation were determined as well. Endogenous antioxidant defence status, reduced glutathione (GSH), total thiol-groups (-SH), SOD activity and thrombocyte function were investigated in platelet rich plasma and in whole blood. White blood cell count and free radical production was significantly higher in patients group before surgery than in healthy group (in case of the free radical production the difference proved to be 10 times (p < 0.01)) and elevated continuously during the observation time. The CD11a and CD18 expression of the granulocytes significantly decreased right after the revascularization, but with a gradual elevation, until the 7th day they exceed the ischaemic value. GSH concentration decreased significantly 2 and 24 hours after surgery and total thiol groups (-SH) followed the same kinetics. SOD activity was significantly lower in patients group haemolysates before surgery when it was measured in healthy groups (p < 0.01) and decreased further significantly 24 hours after the surgery (p < 0.01 vs. before surgery). Suppressed thrombocyte aggregation was detected in platelet rich plasma and in whole blood during the observation excepted the one week samples, where a highly significant elevation in ADP and collagen induced aggregation were observed. Our results show a great alteration in the antioxidant-prooxidant balance and the insufficiency of platelet aggregation's inhibition after peripheral vessel closure and revascularization intervention. We suggest the monitoring of the antioxidant status and thrombocyte function of patients going to underwent surgical intervention and if it necessary the therapeutic help.

Comparison of inflammatory response following coronary revascularization with or without cardiopulmonary bypass.

BACKGROUND: It is well known that conventional coronary revascularization is associated with a pronounced systemic inflammatory response due to the application of cardiopulmonary bypass (CPB). OBJECTIVE: To compare the effects of coronary artery bypass grafting (CABG) with (on-pump) or without (off-pump) extra-corporeal circulation observing certain inflammatory response parameters. METHODS: TWENTY PATIENTS UNDERGOING CABG WITH (CPB GROUP: 10 patients) or without (off-pump coronary artery bypass grafting [OPCAB] group: 10 patients) CPB were enrolled in this prospective, randomized study. Blood samples were collected three times during the operation and on postoperative days 1, 2, 3 and 7. The plasma level of proinflammatory cytokine tumor necrosis factor (TNF)-alpha was measured by enzyme-linked immunosorbent assay method following stimulation, and the expression of adhesion molecules (CD11, CD18) of leukocytes were determined by flow cytometry. Furthermore, white blood cell (WBC) and neutrophil count were carried out. RESULTS: The WBC and neutrophil counts rose markedly in both groups following the operation and remained at this increased level during the observation period. There was a significant difference in WBC and neutrophil counts between the two groups of patients on postoperative day 7. A significant difference in the level of TNF-alpha was found between the two groups on postoperative day 2 (P<0.05). An intense increase was observed with CPB, which significantly exceeded the values of the OPCAB group without extracorporeal circulation in the early postoperative period. The CD11a and CD18 expression of leukocytes decreased during the operation and on postoperative day 1; thereafter, it increased markedly. There was a significant difference in adhesion molecule expression between the two groups on postoperative day 2. CONCLUSION: The investigation revealed that inflammatory response reactions following extracorporeal circulation could be reduced significantly using the off-pump technique.

[Polytetrafluoroethylene graft in a long segment of the esophagus]. / Politetrafluroetilén alkalmazása hosszú szakaszú légcsópótlásban.

Treatment for long segment circular defects of the trachea still represent a challenge. Short-segment lesions can be treated with primary reconstruction. Segmental grafting is necessary if primary reconstruction is impossible. We investigated the use of politetrafluoroethylene (PTFE) grafts for tracheal grafting. Forty-nine adult New Zealand white rabbits were divided in 7 groups in which we compared the effects of continuous and interrupted suture techniques, and various positioning of the graft. Length of survival, changes in intraoperative tracheal microcirculation were measured, microscopic alterations of the trachea, and the anastomosis were studied. Continuous sutures significantly decreased local microcirculation. Using interrupted sutures this effect was not seen. The frequent development of granulation tissue was reduced by using internal telescopic anastomosis. We found that PTFE graft with internal telescopic anastomosis using interrupted sutures is superior to all other techniques.

Intestinal ischemic preconditioning in rats and NF-kappaB activation.

Cold preservation prior to small-bowel transplantation can moderate tissue injury, although it is unable to protect the bowel graft from acute reperfusion injury. One method to reduce oxidative stress is ischemic preconditioning (IPC). The limited data regarding IPC of the bowel encouraged us to investigate the key factor in this process, i.e., the activation of nuclear factor-kappa binding (NF-kB) in bowel tissue. The intestine was preconditioned by various cycles of IPC on rats. Activation of NF-kB was detected by a chemiluminescence-based ELISA method. Our findings showed that NF-kB level was elevated significantly 30 min after IPC. One hour following IPC, NF-kB decreased to control level; 2 h after IPC, the level significantly increased again. These changes were independent of the number of IPC cycles. Our experiments with various IPC cycles revealed that even a very short IPC cycle was able to activate the IPC cascade in small-bowel tissue.

Effect of acetylsalicylic acid on nuclear factor-kappaB activation and on late preconditioning against infarction in the myocardium.

Nuclear factor-kappaB (NF-kappaB) plays an essential role in the intracellular signal transduction of the second window of protection (SWOP). Acetylsalicylic acid (ASA) blocks NF-kappaB-dependent gene activation in leukocytes and endothelial cells through preventing phosphorylation and subsequent degradation of the inhibitor IkappaB-alpha. This study investigated the effect of ASA on the late phase of ischemic preconditioning (PC) against myocardial infarction and on the activation of NF-kappaB in the preconditioned myocardium. Conscious rabbits were subjected to 4 cycles of 5 minutes of coronary occlusion and 5 minutes of reperfusion together with 3 different doses of ASA (5 mg/kg; 25 mg/kg; 130 mg/kg). After 30 minutes of reperfusion we determined the activation of NF-kappaB with an electrophoretic mobility shift assay (EMSA). Twenty-four hours later, after 30 minutes of test ischemia, we performed infarct size analysis using triphenyltetrazolium-chloride (TTC) staining. Neither 5 mg/kg (antithrombotic dose) nor 25 mg/kg (analgesic/antipyretic dose) of ASA interfered with the NF-kappaB activation and the protective effect of late preconditioning against myocardial infarction. In contrast, NF-kB activation and late PC effect were completely abrogated by 130 mg/kg of ASA. Our results suggest that nonselective doses of NSAIDs should be used with caution in patients with atherosclerotic cardiovascular disease because they may deprive the heart of its innate defensive response.