Povezanost karakteristika intraluminalnog tromba prikazanih magnetnom rezonancijom sa njegovim biohemijskim odlikama i morfološkim osobenostima zida infrarenalne aneurizme abdominalne aorte

Abstract

najvećem broju slučajeva sadrži intraluminalni tromb (ILT) u aneurizmatskoj kesi. Uprkos decenijama intenzivnog istraživanja, uticaj ILT-a na progresiju AAA ostao je nedovoljno jasan. Mnoge kliničke studije su potvrdile ulogu matriksmetaloproteinaza (MMP-ova), hemokina i elastaza sekretovanih u ILT-u u razvoju AAA. Mijeloperoksidaze, elastase, MMP-2, 8 i 9 i activator plazminogena tipa urokinaze iz ILT-a mogu imati značajnu ulogu u razgradnji elastina i kolagena tip I i III u aortnom zidu. Definisati adekvatnu dijagnostičku metodu u preoperativnoj evaluaciji efekata ILT-a na zid AAA je izuzetno važno u individualnoj proceni rizika od rupture. Ultrazvučni pregled i kompjuterizovana tomografija nisu dovoljno senzitivne da bi procenile razlike u strukturi ILT-ova. Pregled magnetnom rezonancom (MR) omogućava razlikovanje ILT-ova na osnovu različitih intenziteta signala, te je cilj ovog istraživanja bio da se ispita mogućnost MR pregleda u proceni biološke aktivnosti ILT-a i proteolitičkih procesa u zidu infrarenalne AAA. MATERIJAL I METODE Istraživanje je sprovedeno u vidu studije preseka u Klinici za vaskularnu i endovaskularnu hirurgiju Kliničkog centra Srbije u periodu od aprila 2017. do februara 2018. godine. U navedenom periodu otvorenom hirurškom lečenju podvrgnuto je ukupno 155 bolesnika sa asimptomatskom AAA, od kojih je 50 uključeno u studiju na osnovu uključujućih (prisustvo tromba u aneurizmi, degenerativna i fuziformna infrarenalna AAA planirana za otvoreno hirurško lečenje transperitonealnim pristupom) i isključujućih kriterijuma (asimptomatski bolesnici planirani za endovaskularni tretman, bolesnici sa potkovičastim bubregom, inflamatorne i infektivne AAA, sakularne AAA, kontraindikacije za MR pregled i primenu kontrasta). Pre operativnog zahvata, tokom iste hospitalizacije, pacijenti uključeni u studiju ispitani su MR pregledom. Tokom operacije uzimani su uzorci ILT-a i zida AAA za biohemijsku analizu. Pregled magnetnom rezonancom Pregled je rađen „3 T Siemens Skyra scanner“ aparatom (Skyra Siemens, Berlin, Nemačka) sa 32-kanalnom matricom i 4-kanalnom zavojnicom za abdomen. Analizirani su aksijalni preseci na nivou najvećeg transverzalnog dijametra AAA dobijeni upotrebom T1-weighted (T1W) sekvence nakon intravenske aplikacije paramagnetnog kontrastnog sredstva u arterijskoj fazi pregleda. Podaci dobijeni MR pregledom obrađivani su i analizirani na Syngo (Siemens, Berlin, Nemačka) radnim stanicama uobičajenim alatom...

intraluminal thrombus (ILT). Despite decades of intensive research, the implications of ILT on AAA propagation are still unclear. Many clinical studies have confirmed the role of ILT’s locally secreted matrix metalloproteinases (MMPs), chemokines, and elastases in AAA development. ILTs secrete myeloperoxidases, elastases, MMP 2, 8 and 9, and urokinase-type plasminogen activator, all of which are critical for elastin and collagen type I and III degradation in the aortic wall. In the clinical setting, defining the best imaging method for preoperative evaluation of the effects of ILT on the AAA wall is essential for individual assessment of AAA rupture risk. Ultrasonography and computed tomography angiography are not sensitive enough to identify differences in ILT structure. Magnetic resonance imaging (MRI) is a more adequate method of depicting the structural variations of ILT based on differential signal intensity (SI). Therefore, the aim of the present study was to analyze correlation of the SI of ILTs presented on MRI with the biochemical activity of ILTs and their proteolytic effects on the AAA wall. MATERIAL AND METHODS From April 12, 2017 to February 5, 2018, a single center, cross-sectional study was conducted at the Clinic for Vascular and Endovascular Surgery in Belgrade, Serbia. The study included asymptomatic patients with infrarenal AAA who underwent open surgical repair. During the study period, 155 patients with asymptomatic AAA underwent open surgical repair. After application of inclusion (degenerative and fusiform infrarenal AAA with ILT inside the sac underwent open surgical repair through a midline transperitoneal approach) and exclusion criteria (asymptomatic patients scheduled for endovascular treatment, AAA associated with horseshoe kidney, inflammatory or mycotic AAA, saccular AAA, contraindications for MRI and contrast administration), a total of 50 patients were included in the study. Before surgery, all patients selected for the study were evaluated with MRI. ILT and AAA wall samples for biochemical analysis were harvested during the surgery. Measured MRI variables MRI was conducted with a 3-Tesla whole-body MRI scanner (Skyra, Siemens, Berlin, Germany) using a standard 32-channel surface 4-receiver coil. MRI data were processed and analyzed by Syngo workstations (Siemens, Berlin, Germany). AAA diameter was measured at the level of maximum diameter (Dmax) on T1w images after contrast administration in the arterial phase...