Experimental Models of Hemorrhagic Shock: A Review

Massive blood loss leading to hypovolemic shock is still a life-threatening situation. Recently, a great number of investigations have been conducted in order to understand the pathophysiological and immunological changes taking place during shock and to develop treatment strategies. These preclinical trials are based on animal studies. Although a wide spectrum of species and experimental models are available to researchers, it is rather difficult to create an ideal animal model to study hemorrhagic shock. A major challenge for investigators is the generation of a system which is simple, easily reproducible and standardized, while being an accurate replica of the clinical situation. The goal of this review is to summarize the current experimental models of hemorrhagic shock, highlighting their advantages and disadvantages to help researchers find the most appropriate model for their own experiments on hypovolemic shock

HeRO (Hemodialysis Reliable Outflow) graft alkalmazása tartós hemodialíziskezelés során = The use of HeRO (Hemodialysis Reliable Outflow) graft in hemodialysis

Absztrakt: A végstádiumú veseelégtelen betegek kezelésének folyamatos fejlődése és túlélési eredményeinek javulása következtében egyre nagyobb kihívást jelent tartós, jól működő arteriovenosus összeköttetés létrehozása. A HeRO (Hemodialysis Reliable Outflow) rendszer lehetővé teszi megfelelően funkcionáló arteriovenosus sönt képzését olyan betegekben, akiknél mindkét oldali centrális vénás elzáródás miatt felső végtagi sönt készítése már nem jönne szóba. Hazánkban először ültettünk be eredményesen HeRO graftot egy tartós hemodialízisben részesülő betegnél. Célunk az ezzel kapcsolatos tapasztalataink bemutatása. Esetismertetésünkben a betegdokumentációt, a pre- és posztoperatív képalkotó vizsgálatokat tekintettük át. Betegünk (73 éves nő) 12 éve részesül rendszeres hemodialíziskezelésben. Mindkét felső végtagon számos alkalommal történt arteriovenosus fistula létrehozása, fistulathrombectomia, valamint mindkét oldalon sor került tartós tunelizált dialíziskanül használatára. Bal oldali könyöktáji fistulájának elzáródását követően konvencionális sönt képzése nem jött szóba a mindkét oldalon kialakult vena subclavia occlusióra tekintettel, ezért HeRO graft implantációja mellett döntöttünk. A sikeres graftimplantációt követően 7, majd 12 hónappal történt graftthrombectomia és endovascularis intervenció, melyet követően ismét jó hatásfokú hemodialízis végezhető a grafton keresztül. A mindkét oldali felső testfél centrálisvéna-occlusiója esetén a HeRO graftrendszer megfelelő alternatívája lehet a tunelizált dialíziskanülöknek és alsó végtagi arteriovenosus összeköttetéseknek. Orv Hetil. 2019; 160(31). 1231–1234. | Abstract: Creating durable vascular access has become more complicated with the improvement of the management and with the increasing survival of patients with end-stage renal disease. HeRO (Hemodialysis Reliable Outflow) graft allows to maintain vascular access on the upper limb in patients with the presence of bilateral central venous occlusion. Our institute was the first in Hungary to perform a HeRO graft implantation in a patient receiving regular hemodialysis. Our objective was to present our findings with this recent innovation. Case report, medical documentation and imaging studies were reviewed. The patient (73-year-old, female) has been receiving hemodialysis since 12 years with the history of several arteriovenous fistula (AVF) creations, thrombectomies, use of central venous catheter in both sides. Following the occlusion of a left cubital arterio-venous fistula, none of the conventional vascular access types could have been performed due to bilateral subclavian vein occlusion. Successful HeRO graft implantation was performed. The patient underwent graft thrombectomy and endovascular intervention 7 and 12 months after the original procedure. After both reoperations, the graft functioned well for hemodialysis. HeRO graft can be a good alternative to central venous catheters and lower limb arterio-venous grafts in cases of bilateral central venous occlusion. Orv Hetil. 2019; 160(31): 1231–1234

Postconditioning in major vascular surgery: prevention of renal failure

This study investigates teachers in the Swedish ten-year compulsory school who use ICT(Information and communication technology) in their classroom practice. It poses andgives answers to questions about what is contributing most to explain why they choose touse computers and information technology in their work with students/pupils and usesmultiple regression analysis in order to investigate the best pattern of predictive variables.A significant model emerged suggesting that teachers using ICT with students wereinterested in changing their classroom practice. They also felt self-efficacious in usingcomputers in education and they have positive attitudes toward using ICT in education.The present investigation differs from other studies in that it examines teachers whoalready are using technology in their classroom practice and it could be seen as a buildingblock in the development of knowledge about how teachers can become more competentand confident in using ICT in their pedagogical work in classroom practice

Muscle Fiber Viability, a Novel Method for the Fast Detection of Ischemic Muscle Injury in Rats

Acute lower extremity ischemia is a limb- and life-threatening clinical problem. Rapid detection of the degree of injury is crucial, however at present there are no exact diagnostic tests available to achieve this purpose. Our goal was to examine a novel technique - which has the potential to accurately assess the degree of ischemic muscle injury within a short period of time - in a clinically relevant rodent model. Male Wistar rats were exposed to 4, 6, 8 and 9 hours of bilateral lower limb ischemia induced by the occlusion of the infrarenal aorta. Additional animals underwent 8 and 9 hours of ischemia followed by 2 hours of reperfusion to examine the effects of revascularization. Muscle samples were collected from the left anterior tibial muscle for viability assessment. The degree of muscle damage (muscle fiber viability) was assessed by morphometric evaluation of NADH-tetrazolium reductase reaction on frozen sections. Right hind limbs were perfusion-fixed with paraformaldehyde and glutaraldehyde for light and electron microscopic examinations. Muscle fiber viability decreased progressively over the time of ischemia, with significant differences found between the consecutive times. High correlation was detected between the length of ischemia and the values of muscle fiber viability. After reperfusion, viability showed significant reduction in the 8-hour-ischemia and 2-hour-reperfusion group compared to the 8-hour-ischemia-only group, and decreased further after 9 hours of ischemia and 2 hours of reperfusion. Light- and electron microscopic findings correlated strongly with the values of muscle fiber viability: lesser viability values represented higher degree of ultrastructural injury while similar viability results corresponded to similar morphological injury. Muscle fiber viability was capable of accurately determining the degree of muscle injury in our rat model. Our method might therefore be useful in clinical settings in the diagnostics of acute ischemic muscle injury

Arteria iliaca aneurysma nyitott és endovascularis kezelése [Open and endovascular repair of iliac artery aneurysms]

Introduction and aim: Iliac artery aneurysms make up 2% of all aneurysms. There are only a few data available on the results of surgical treatment, therefore the optimal treatment is unclear. Our objective was the retrospective analysis of the perioperative morbidity and mortality of patients who underwent iliac artery surgery as well as the comparison of elective open surgery and endovascular iliac aneurysm repair (EVIAR). Method: Retrospective analysis of patients who underwent surgery for iliac artery aneurysm between 1 January 2005 and 31 December 2014. Results: During the 10-year period, 62 patients with a mean age of 68.9 years underwent elective surgery for iliac artery aneurysm (54 males, 87.1%). In 10 cases acute surgery was performed due to aneurysm ruptures (13.9%), 3 patients died within the perioperative period (30%). Regarding anatomical localisation, aneurysm developed mostly on the common iliac artery (80.6%). As an elective surgery, 35 patients (56.5%) underwent open surgery, 25 (40.3%) underwent EVIAR and other endovascular interventions were performed in 2 cases (3.2%). Postoperative complications (1 patient [4.0%] vs. 17 patients [48.5%]; p<0.001) and intensive care treatment (29 patients [82.8%] vs. 2 patients [8.0%]; p<0.001) were significantly rarer after EVIAR than after open surgery. Furthermore, EVIAR resulted in considerably shorter postoperative hospital stays (4.7 +/- 2.3 days vs. 11.8 +/- 12.2 days; p = 0.006) and significantly less blood transfusion demand (1 patient [4.0%] vs. 26 patients [74.2%]; p<0.001). There were no significant differences regarding long-term survival rates between EVIAR and open surgery (81.4% vs. 71.4%; p = 0.95). Conclusion: In case of the surgical treatment of iliac artery aneurysms, owing to the lower complication rates and shorter postoperative length of stay, EVIAR is primarily recommended

Homograftok használata érsebészeti fertőzésekben = Use of allografts in vascular surgery infections

Az érsebészeti graftinfekciók és a fertőzött szöveti környezetben végzett érrekonstrukciók is jelentős morbiditással és mortalitással járó állapotok, melyek komoly kihívást jelentenek az operáló érsebész számára. A szeptikus érsebészetben nincs egységes álláspont sem az operatív stratégiát, sem az érpótlásra használt graft anyagát illetően. Az ajánlások alapján az elsőként választandó a beteg saját szervezetéből származó, ún. autológ graft használata, azonban ennek hiánya vagy alkalmatlansága esetén ígéretes lehet a szervdonorból explantált, ún. homograft alkalmazása. Célunk az elmúlt 7 év során megjelent, érsebészeti szeptikus kórállapotokban felhasznált homograftokkal foglalkozó szakirodalmi közlemények áttekintése volt. Az adatgyűjtés a 2016. január 1. és 2022. december 31. közötti időszakot áttekintve történt. A PubMed és Medline adatbázisokban szisztematikus keresés során az érsebészeti szeptikus kórállapotokban alkalmazott, krioprezervált homograft beültetésének eredményeiről beszámoló közleményeket választottuk ki és elemeztük. A publikációk eredményeinek elemzése a következő végpontok alapján történt: a vizsgálat jellege, demográfiai adatok, mortalitási arány, a grafthoz köthető szövődmények és a reoperáció aránya, a graft nyitva maradása, végtagmentési arány, graft-újrafertőződési arány és túlélési arány. A szisztematikus keresést követően 16 közlemény adatait dolgoztuk fel. A publikációkat két csoportra osztottuk: aortán végzett érműtétek (aorta) és perifériás ereken végzett érműtétek (perifériás). Az aortacsoportba 12 közlemény került, melyek 542 beteg adatait dolgozták fel. A korai halálozási arány (<30 nap) 2,8% és 42,8% közötti, a homografttal kapcsolatos reoperációs arány 5,9% és 29% közötti, míg a graft-újrafertőződési arány 10% alatti volt. A perifériás csoportba 4 vizsgálat került, amelyek 252 beteg adatait fedik le. A korai halálozási arány (<30 nap) 2,0% és 38% közötti, az allografttal kapcsolatos reoperációs arány 4,0% és 55% közötti (korai és késői), míg a graft-újrafertőződési arány 4% körüli volt. Összefoglaló közleményünk adatai alapján az érsebészeti fertőzések során felhasznált homograftokkal végzett beavatkozások mortalitása és reoperációs aránya nem ítélhető meg egyértelműen, azonban az alacsony újrafertőződési arányból és az előnyös biológiai tulajdonságokból adódóan megfelelő választás lehet érrekonstrukciók során. | With the growing number of patients with vascular endografts, the number of patients with graft infections has also increased. Septic conditions and the choice of grafts are an important challenge in vascular surgery. The aim of this study was to review the literature of the last 7 years showing allograft use in septic conditions in vascular surgery which helps provide insight into the current results of vascular allografts. Data were collected between 1st January 2016 and 31st December 2022. A systematic search was conducted for publications of cryopreserved allograft usage for vascular infection in PubMed and Medline databases. The results of the publications were reviewed based on the following key endpoints: study design, patient’s characteristics, mortality rate, graft related complication and reintervention rate, graft patency, limb salvage, graft reinfection rate and survival rate. After a systematic search, 16 publications were included. The articles were divided into two groups: aortic and peripheral. The aortic group included 12 studies covering the data of 542 patients. Early mortality rate (<30 days) was between 2.8% and 42.8%. Allograftrelated reintervention rates ranged between 5.9% and 29% (early and late). The rate of graft reinfection was below 10%. 4 studies were included in the peripheral group covering the data of 252 patients. Early mortality rate (<30 days) was between 2.0% and 38%. Allograft-related reintervention rates ranged between 4.0% and 55% (early and late). Reinfection rate was around 4%, but only poor quality data were available. Infections in vascular surgery remain a challenging problem, however, cryopreserved allografts show low reinfection rate and reasonable durability, thus, allografts may be an acceptable option for reconstruction