Abdominal Aortic Infections

Background. Abdominal aortic infections are dreaded disorders in vascular surgery, linked to high morbidity and mortality. Mycotic aneurysm as a primary infection of the abdominal aorta (MAAA) and an aortic graft infection (AGI) are different entities; however, due to bacterial presence in aorta and perivascular tissue, the principles of management are the same. Due to low incidence and complexity of disease, the high-quality evidence is lacking to define whether prosthetic aortic reconstructions in infectious conditions are utterly safe or whether biological reconstruction material should be preferred despite some shortcomings in durability. In complex abdominal surgery encompassing visceral aorta, prolonged aortic clamping above renal arteries is a risk factor for acute ischaemic kidney injury. In such situations, renal protection is recommended in order to avoid irreversible damage and renal replacement therapy. Aims. The aim of current study was to evaluate the infection resistance and durability of biological grafts as an aortic reconstruction material in abdominal aortic infections and to estimate the mortality after such reconstructions. Furthermore, efficacy of temporary axillo-renal bypass in prevention of renal ischaemic damage from major aortic surgery was estimated. Materials. The study comprises two parts. In the first part, 132 patients were analysed after being treated for aorto-iliac infections with arterial resection and reconstruction with a biological graft. Study I included patients treated due to AGI with femoral vein grafts, Study II included patients in whom the arterial infection was treated using cryopreserved venous allografts, and Study III included patients who were treated with various biological grafts for a primary aortic infection. The primary endpoints were postoperative mortality and reinfection rates, secondary endpoints were treatment-related mortality, overall mortality and graft reinterventions. During the second part of the study, (Study IV) patients who underwent temporary axillo-renal bypass during a major aortic intervention were retrospectively analysed. Outcome measures were postoperative kidney injury and 30-day mortality. Studies I, II and IV entailed retrospective analyses of patients treated at Helsinki University Hospital, while Study II was multicentre retrospective analysis of patients from six countries. Results. Sixty-four percent (64%, n=85) of the patients underwent surgery for an abdominal aortic infection with autologous femoral veins (FV), 17% (n=23) with cryopreserved venous allografts (CVA), 9% (n=12) with xenopericardial tube grafts, 5% (n=7) with cryopreserved arterial allografts, and 4% (n=5) with fresh arterial allografts. Most common indications for operation were aortic graft infection with an incidence of 51% (n=67) and mycotic abdominal aneurysm with 45% (n=60). The 30-day mortality was 9% for patients treated with FV for an AGI, 9% for patients treated for mixed infectious indications with cryopreserved venous allografts, and 5% for patients treated with various biological reconstructions due to MAAA,. The respective treatment-related mortality rates in these cohorts were 18%,13% and 9%. The reinfection rate was 2% (n=3) and 11% (n=14) of the grafts needed reinterventions at the mid-term follow-up, with stenotic lesions in femoral veins as the most common indication (n=9/14). Kaplan-Meier estimation of survival at 5 years was 59% (95% confidence interval, [CI] 43% – 73%) for patients treated with FV due to AGI and 71% (95% CI 52% –89%) for patients treated with mixed biological materials for MAAA. For patients treated with cryopreserved allografts for mixed indications, estimated survival at 2-years was 70% (95% CI 49% – 91%). Sixteen patients were operated with temporary axillo-renal bypass during aortic surgery. Despite short median renal ischaemia time of 24.5 minutes, 6 (38%) patients suffered acute kidney injury (AKI), of whom 4 had renal insufficiency preoperatively. One patient needed temporary renal replacement therapy, at one-month follow-up, however, renal function had returned to its baseline level or improved in all patients. The 30-day and in-hospital mortality was nil. Conclusions. Biological reconstruction material is infection resistant and reasonably durable in midterm analysis. Early postoperative and overall mortality rates are acceptable after treatment of such a complex entity as abdominal aortic infections. Furthermore, temporary axillo-renal bypass is safe and feasible in diminishing acute kidney injury during major aortic surgery.Primääri aortan infektio eli mykoottinen aneurysma ja aortan proteesi-infektio ovat vakavimpia tilanteita verisuonikirurgiassa, ja johtavat kuolemaan ilman hoitoa. Infektion parantamiseksi vierasmateriaali ja tulehtunut aorttaseinämä on pääsääntöisesti poistettava kokonaan ja raajojen verenkierto turvattava uudella verisuoniohiteella. Mikäli infektoitunut proteesi korjataan uudella proteesilla, on uusintainfektion vaara korkea. Tässä väitöskirjassa tutkitaan biologisten materiaalien toimivuutta aorttainfektioiden hoidossa sekä väliaikaisen munuaisohituksen toimivuutta akuutin munuaisen vajaatoiminnan ehkäisyssä potilailla, joilla aortta joudutaan pihdittämään munuaisvaltimon yläpuolelta korjauksen aikana. Väliaikaista ohitusta käyttämällä vältetään munuaisiskemia aorttapihdityksen aikana. Vuosina 2000-2018 tehdyistä biologisista ohituksista on kerätty seurantatiedot retrospektiivisesti HUS:ista; mykoottisten aneurysmien potilastiedot HUSin lisäksi viidestä eurooppalaisesta keskuksesta. Väliaikaisista munuaisohituksista on kerätty tiedot vuosilta 2007-2012. Tutkimuksessa arvoitiin biologisen materiaalin kestävyyttä tulehduksellisissa olosuhteissa, leikkauksenjälkeistä sairastavuutta ja pitkäaikaista eloonjäämistä. Munuaistoiminta arvioitiin ennen leikkausta ja sen jälkeen. Yhteensä tutkimusjakson aikana tehtiin yhteensä 132 biologista ohitusta aorttatulehdusten takia: rekonstruktiomateriaalina oli potilaan oma syvälaskimo 85:ssa tapauksessa, pakastettu elinluovuttajan laskimo 23:ssa tapauksessa, pakastettu elinluovuttajan valtimografti 7:ssa tapauksessa, tuore luovuttajan valtimo 5:ssa tapauksessa ja kaupallisesta härän perikardista käsin tehty tuubigrafti 12:ssa tapauksessa. Uusinta-infektioita esiintyi 2%:lla ja keskipitkän seurannan aikana 11%:lle tehtiin ohitteen korjaustoimeenpide. Ohiteen repeytymisestä johtuvia kuolemia ei ollut seuranta-aikana. Leikkauksen jälkeinen kuolleisuus oli 5%-13% kolmessa eri tutkimuksessa ja pitkäaikainen eloonjääminen 5 vuoden kohdalla 71%-59%. Leikkauksen jälkeinen munuaisten vajaatoiminta ilmaantui 6/16 potilaalle, mutta kuukauden kuluttua leikkauksesta munuaistoiminta oli palautunut lähtötasoon tai parantunut kaikissa tapauksissa. Yksikään potilas ei kuollut leikkauksen jälkeisessä vaiheessa väliaikaisen munuaisohituksen jälkeen. Tutkimuksemme mukaan biologiset ohitukset ovat infektioresistentteja ja suhteellisen kestäviä aortan korjausmateriaaleja infektio-olosuhteissa. Kuolleisuus on leikkauksen jälkeen merkittävää, mutta ottaen huomioon taudin vakavuus ja erittäin korkea mortaliteetti ilman leikkaushoitoa, kuolleisuus on hyväksyttävä sekä lyhyellä että pitkällä aikavälillä. Väliaikainen munuaisohite on tehokas tapa välttää munuaisten vajatoiminnan kehittymistä tai pahenemista haastavissa aorttaleikkauksissa

Vatsa-aortan infektiot

Teema : aorttaAortan tai aorttaproteesin infektio on hengenvaarallinen tilanne. Oireet ovat usein hyvin epämääräisiä, mikä vaikeuttaa diagnosointia, ja hoito saattaa viivästyä. Mikrobilääkitys on hoidon kulmakivi ja jatkuu elinikäisenä, mikäli proteesia ei poisteta. Infektion parantamiseksi pysyvästi proteesimateriaali ja tulehtunut aortanseinämä tulee poistaa kokonaan ja raajojen verenkierto turvata uudella verisuonirekonstruktiolla. Uusintainfektioiden välttämiseksi tehdään aorttarekonstruktio biologisella materiaalilla, mihin kuitenkin liittyy suuri leikkaustrauma vakavasti sairaalle potilaalle tai epävarmuus ohitussiirteen kestävyydestä. Proteesirekonstruktioon taas liittyy huomattavan suuri uusintainfektion riski. Proteesin poistoa sekä kainalo- ja nivusvaltimon välistä proteesiohitusta verenkierron turvaamiseksi ei enää nykyään suosita. Puhkeamisuhan välttämiseksi voidaan infektoituneen aortan sisälle joskus asettaa stenttigrafti ja jättää mikrobilääkehoito pysyväksi. Selkeää konsensusta parhaasta leikkausmenetelmästä ei ole, vaan moniammatillinen tiimi räätälöi hoidon potilaskohtaisesti.Peer reviewe

Infective Native Aortic Aneurysms : A Delphi Consensus Document on Terminology, Definition, Classification, Diagnosis, and Reporting Standards

Publisher Copyright: © 2022 The Author(s)Objective: There is no consensus regarding the terminology, definition, classification, diagnostic criteria, and algorithm, or reporting standards for the disease of infective native aortic aneurysm (INAA), previously known as mycotic aneurysm. The aim of this study was to establish this by performing a consensus study. Methods: The Delphi methodology was used. Thirty-seven international experts were invited via mail to participate. Four two week Delphi rounds were performed, using an online questionnaire, initially with 22 statements and nine reporting items. The panellists rated the statements on a five point Likert scale. Comments on statements were analysed, statements revised, and results presented in iterative rounds. Consensus was defined as ≥ 75% of the panel selecting “strongly agree” or “agree” on the Likert scale, and consensus on the final assessment was defined as Cronbach's alpha coefficient > .80. Results: All 38 panellists completed all four rounds, resulting in 100% participation and agreement that this study was necessary, and the term INAA was agreed to be optimal. Three more statements were added based on the results and comments of the panel, resulting in a final 25 statements and nine reporting items. All 25 statements reached an agreement of ≥ 87%, and all nine reporting items reached an agreement of 100%. The Cronbach's alpha increased for each consecutive round (round 1 = .84, round 2 = .87, round 3 = .90, and round 4 = .92). Thus, consensus was reached for all statements and reporting items. Conclusion: This Delphi study established the first consensus document on INAA regarding terminology, definition, classification, diagnostic criteria, and algorithm, as well as reporting standards. The results of this study create essential conditions for scientific research on this disease. The presented consensus will need future amendments in accordance with newly acquired knowledge.Peer reviewe

Open Repair of Mycotic Abdominal Aortic Aneurysms With Biological Grafts : An International Multicenter Study

Background-The treatment of mycotic abdominal aortic aneurysm requires surgery and antimicrobial therapy. Since prosthetic reconstructions carry a considerable risk of reinfection, biological grafts are noteworthy alternatives. The current study evaluated the durability, infection resistance, and midterm outcome of biological grafts in treatment of mycotic abdominal aortic aneurysm. Methods and Results-All patients treated with biological graft in 6 countries between 2006 and 2016 were included. Primary outcome measures were 30- and 90-day survival, treatment-related mortality, and reinfection rate. Secondary outcome measures were overall mortality and graft patency. Fifty-six patients (46 males) with median age of 69 years (range 35-85) were included. Sixteen patients were immunocompromised (29%), 24 (43%) had concomitant infection, and 12 (21%) presented with rupture. Bacterial culture was isolated from 43 (77%). In-situ aortic reconstruction was performed using autologous femoral veins in 30 patients (54%), xenopericardial tube-grafts in 12 (21%), cryopreserved arterial/venous allografts in 9 (16%), and fresh arterial allografts in 5 (9%) patients. During a median follow-up of 26 months (range 3 weeks-172 months) there were no reinfections and only 3 patients (5%) required assistance with graft patency. Thirty-day survival was 95% (n=53) and 90-day survival was 91% (n=51). Treatment-related mortality was 9% (n=5). Kaplan-Meier estimation of survival at 1 year was 83% (95% confidence interval, 73%-94%) and at 5 years was 71% (52%-89%). Conclusions-Mycotic abdominal aortic aneurysm repair with biological grafts is a durable option for patients fit for surgery presenting an excellent infection resistance and good overall survival.Peer reviewe

Infective Native Aortic Aneurysm : a Delphi Consensus Document on Treatment, Follow Up, and Definition of Cure

Objective: Evidence is lacking to guide the management of infective native aortic aneurysm (INAA). The aim of this study was to establish expert consensus on surgical and antimicrobial treatment and follow up, and to define when an INAA is considered cured. Methods: Delphi methodology was used. The principal investigators invited 47 international experts (specialists in infectious diseases, radiology, nuclear medicine, and vascular and cardiothoracic surgery) via email. Four Delphi rounds were performed, three weeks each, using an online questionnaire with initially 28 statements. The panellists rated the statements on a five point Likert scale. Comments on statements were analysed, statements were revised and added or deleted, and the results were presented in the iterative rounds. Consensus was defined as ≥ 75% of the panel rating a statement as strongly agree or agree on the Likert scale, and consensus on the final assessment was defined as Cronbach's alpha > 0.80. Results: All 49 panellists completed all four rounds, resulting in 100% participation. One statement was added based on the results and comments of the panel, resulting in 29 final statements: three on need for consensus, 20 on treatment, five on follow up, and one on definition of cure. All 29 statements reached agreement of ≥ 86%. Cronbach's alpha increased for each consecutive round; round 1, 0.85; round 2, 0.90; round 3, 0.91; and round 4, 0.94. Thus, consensus was reached for all statements. Conclusion: INAAs are rare, and high level evidence to guide optimal management is lacking. This consensus document was established with the aim of helping clinicians manage these challenging patients, as a supplement to current guidelines. The presented consensus will need future amendments in accordance with newly acquired knowledge.Peer reviewe