50 research outputs found
Determination of biomechanical, anatomical and patophysiological factors influencing wall strength of the abdominal aortic aneurysm and their role in the abdominal aortic aneurysm rupture risk assessment
Uvod. Aneurizma abdominalne aorte je potencijalno fatalno oboljenje koje se preventivno
može leÄiti hirurÅ”ki. Rizik od hirurÅ”kog leÄenja je sve manji meÄutim ma koliko bile retke
komplikacije mogu biti fatalne ili prouzrokovati težak invaliditet. Upravo zato je od velikog
znaÄaja poznavanje rizika od rutpure aeurizme koji se trenutno procenjuje samo na osnovu
najveÄeg preÄnika aneurizme Å”to se pokazuje kao nedovoljno precizno. Ispitivanje uticaja
drugih parametara (biomehaniÄkih, anatomskih, patomorfoloÅ”kih) na nastanak rupture bi
moglo da napredi procenu rizika od ove fatalne komplikacije.
Metod. Ispitivanje je sprovedeno po tipu prospektivne studije koja je obuhvatila 288 bolesnika
sa aneurizmom abdominalne aorte koji su ispitivani ili operisani na Klinici za vaskularnu i
endovaskularnu hirurgiju KCS u periodu od januara 2012 do decembra 2015 godine. Na osnovu
podataka dobijenih multislajsnom kompjuterizovanom tomografijom kod bolesnika su
ispitivani biomehaniÄki parametri koji deluju na zid aneurizme (napon, preÄnik ekvivalentan
riziku od rupture) kao i morfoloki parametri koji bi mogli da ukažu na patofizioloŔke procese
u aneurizmatskoj kesi (zapreminu aneurizme, intraluminalnog tromba, angulacije). Uzorci
prednjeg zida aneurizmatske kese ispitivani su testom inflacije i na taj naÄin im je odreÄivana
snaga i elastiÄnost dok je iz uzorka seruma odreživana aktivnost matriksne metaloproteinaze 9.
Rezultati. ZnaÄajno viÅ”e osoba ženskog pola je bilo u grupi bolesnika sa simptomatskom
odnosno rupturiranom aneurizmom abdominalne aorte, 5/23 (21.73%) prema 12/75 (16%),
p=0.005. Multivarijantni model kojim su ukljuÄeni pol, životna dob, maksimalni preÄnik
aneurizme (MAD,OR=1.063), relativna zapremina intraluminalnog tromba (rILT, OR=1.039)
i ukupna zapremina aneurizme (UZA,OR=1.006) su znaÄajni prediktori rupture aneurizme
abdominalne aorte sa najveÄim naponom u zidu (PWS,OR=1.010) dijametra ekvivalentan
riziku od rupture (RRED,OR=1.031). Merene su vrednosti AUC i cc za iste parametre u modelu
koji kombinuje MAD, TZA i rILT: MAD (0.790, cc=75%), PWS (0.713, cc=73%), RRED
(0.717, cc=55%), TAV (0.756, cc=79%), rILT (0.656, cc=60%) i MAD+TAV+rILT (0.797,
cc=82%). Nije dobijena statistiÄki znaÄajna razlika izmeÄu vrednosti serumske MMP 9 i snage
zida, test korelacije je iznosio 0.174, p=0.135. Konstatovana je statistiÄki znaÄajna povezanost
izmeÄu serumske koncentracije MMP 9 i srednjeg napona u intraluminalnom trombu (cc -
0.371, p=0.016), najveÄeg rizika od rupture (p=0.04) i volumena intraluminalnog tromba (cc
0.324, p=0.03).
ZakljuÄak. ImajuÄi u vidu zadate ciljeve kao i prikazane rezultate može se zakljuÄiti da je zid
aneurizme abdominalne aorte slabije snage kod aneurizmi koje su veÄ rupturirale ili izazivale
simptome Äime je pokazano da snaga zida ima važnu ulogu u procesu nastanka rupture. Na
snagu aneurizmatskog zida je uticala jedino relativna debljina intraluminalnog tromba.
Serumska koncetracija MMP ā 9 se, prema rezultatima ovog istraživanja, ne može koristiti za
procenu snage aneurizmatskog tkiva prilikom predviÄanja rizika od rupture aneurizme
abdominalne aorte. BiomehaniÄki, anatomski odnosno morfoloÅ”ki parametri mogu zaÄajno
unaprediti predviÄanje rizika od rupture u odnosu na koriÅ”Äenje samog dijametra. Najkorisniji
su najveÄi napon, zapremina aneurizme, relativna zapremina intraluminalnog tromba i
dijametar ekvivalentan riziku od rupture. KoriÅ”Äenjem ovih parametara moÄ predviÄanja
nastanka rupture se poveÄava sa 73% na 83.9%.Introduction. Abdominal aortic aneurysm is potentialy fatal disease that can be treated with
preventive operation. Surgical risk, although improving, can lead to death or disability. In this
regard it is of high importance to assess risk of rupture that is nowdays expressed in correlation
to aneurysm diameter what was shown to be less accurate. Assessment of correlation between
other parameters (biomechanical, anatomical, patomorphological) and risk of aneurysm rupture
might improve rupture risk assesment and facilitate decision making.
Methods. This research was conducted in prospective manner at the Clinic for Vascular and
Endovascular surgery and included 288 patients with abdominal aortic aneurysm in the period
from January 2012 to December 2015. Images from multisliced computed tomography were
used for biomechanical analysys to estimate peak wall stress and rupture risk equvivalent
diameter by finite element analysys. Morphological parameters as aneurysm and intraluminal
thrombus volume, angulations and anatomical parmeters were assessed from these images as
well. Samples of anterior wall of aneurysm were tested with inflation test estimating tissue
elasticity and strength while serum level of matrix metalloproteinase 9 were measured as well.
Results. There were significantly more females in the R group: 5/23 (21.73%) comparing to
12/75 (16%) in 4A group, p=0.005. In a multivariable model, including gender and age as
confounder variables, maximal aneurysm diameter (MAD,OR= 1.063), relative intraluminal
thrombus (rILT,OR=1.039) and total aneurysm (TAV,OR=1.006) volume continued to be a
significant predictors of AAA rupture with peak wall stress (PWS,OR=1.010) and rupture risk
equivalent diameter (RRED,OR=1.031). AUC values and correct classification (cc) for the
same parameters and model that combines MAD, TAV and rILT were measured: MAD
(0.790, cc=75%), PWS (0.713, cc=73%), RRED (0.717, cc=55%), TAV (0.756, cc=79%),
rILT (0.656, cc=60%) and MAD+TAV+rILT (0.797, cc=82%)
Conclusion. Based on aim and presented results aneurysm wall is weaker in ruptured and
symptomatic aneurysm outlining importance of wall strength in rupture developement. Wall
strength correlated with relative thrombus thickness. Serum level of MMP-9, based on these
restults, can not be used for tissue strength assessment however thrombus formation can be
suspected in elevated levels of MMP 9. Biomechanical, anatomical and moprhological
paramters can improve rupture prediction in comparison to maximal diameter only. The most
usefull paramters are peak wall stress, aneurysm volume, relative intraluminal thrombus and
rupture risk equivalent diameter. Using these paramters rupture prediction is increased from
73% to 83.9%
Vascular complications in long COVID are very rare
Depending on the methodology thrombotic events during the acute COVID-19 infection were noted from 20 - 85%. Following the acute phase of the disease, it was noted that a subgroup of patients had various non-specific, prevailing symptoms for weeks, or even months and such a condition was accepted as a long COVID. Having in mind mechanisms of vascular complications in acute COVID infection and pathogenesis of long COVID, one would expect similar presentation and consequences of long COVID on human vasculature. We conducted a wide search of the literature on the topic and after screening of titles and abstracts papers with potential inclusion of the data regarding long COVID and vascular symptoms or complications that occurred during the time span of more than then 4 weeks after COVID infection. Research dealing with long COVID are mostly focused on symptoms and laboratory findings due to the nature of this condition. Data regarding vascular complications in these studies are either missing or the incidence of vascular complications was very low. Very few manifestations were related to cardiovascular system and D-dimer was assessed in only two studies showing increased values from very lot to almost in 30% of patients after COVID infection. Finally, in comparison of vascular complications with other viral infections in Sweden on patients undergoing diagnostic tests for venous thromboembolism increased risk for VTE in COVID-positive patients was proved. In the group of patients with chronic cardiovascular disease, the risk of arterial and venous thrombotic events after COVID infection is substantially higher. In comparison with seasonal influenza burden with coagulation disorders, pulmonary embolism, acute phlebitis, thrombophlebitis or thromboembolism and arterial embolism were higher and cumulative incidence was reported from 0.6 - 5.5% while hazard ration was from 2 - 18. Based on the published literature, vascular complications in the long COVID are very rare. Comparing to a very high rate of thrombotic events in the acute COVID infection and their correlation with severity of clinical presentation of COVID infection, the role and presence of vascular complications in long COVID is without any significance. Future studies focusing on the pathophysiology of long COVID could probably reveal potential mechanisms and explanations for such a difference
Abdominal aortic aneurysm: Risk factors for diametric progression in non-operated patients
Introduction: Abdominal aortic aneurysm (AAA) is a disease of modern age, which occurs mostly in elderly people, after the age of 65 years. Epidemiological studies have shown that the development of AAA is correlated with certain risk factors including smoking, as well as presence of comorbidities like hypertension and hyperlipidemia. In our country, the diagnosis of AAA is based on ultrasound examination. Aim: To analyze the speed and factors influencing the progression of AAA diameter. Material and methods: Our study included 52 patients who were not eligible for surgical treatment. Patients were examined successively and risk factors were observed as well as comorbidities were obtained and life habits of those patients. Results: Average age of patients was 71.5 years. 46 patients (86,5 %) were smokers. Average diameter of AAA was 42.5mm. The correlation between the speed of AAA diameter progression and comorbidities wasn't found. There wasn't found correlation between difference between time interval of next follow-up visit and AAA diameter (x2 = 0.4164, p = 0.549). Average growth of AAA between first and second measurement was 2.79 mm (X = 2.5, S.D. 3.1). There was correlation between initial diametric size and growth of aneurysm R = -0.329 (p = 0.017). Conclusion: In our study we didn't find the correlation between comorbidities and AAA growth. Concerning small number of patients, studies with this topic that analyze larger number of patients are recommended. Patients with smaller AAA showed slower progression in diameter, which require their less frequent follow-up visit
Ekspresija komponenti renin-angiotenzin sistema u humanom karotidnom plaku
Background/Aim. The renin-angiotensin system (RAS) is linked to the development of atherosclerosis (As), including its initiation and progression. Besides the well-known angio-tensin-converting enzyme (ACE), two newer RAS family members are related to vascular remodeling - ACE2 as a homolog of ACE and collectrin [transmembrane protein 27 (TMEM27)] as a homolog of ACE2. Up to now, a limited number of studies have examined the expression of these RAS components in advanced carotid plaque (CP) tissue based on the sex of the patients and plaque phenotypes (PPs). There are two ultrasonographically defined PPs - the hypoechogenic plaque (HoP) and the hyperechogenic plaque (HerP) phenotype. The aim of the study was to investigate whether there was a correlation between the expression of RAS components in the CP and the sex and PPs of patients. Methods. We examined 74 patients with advanced CP who underwent carotid endarterectomy. The intraplaque expression of RAS components was determined with the real-time polymerase chain reaction, using the TaqManĀ® gene expression assays and Western blot. A two-way ANOVA followed by a post-hoc Tukey test was performed for the statistical analysis of results. Results. No interaction was recorded between the sex of the patients and PPs in influencing the relative expression of ACE and TMEM27 messenger RNA (mRNA) (p > 0.05). In 56.06% of plaque samples, no expression of ACE2 mRNA was detected. Among the plaques where ACE2 mRNA expression was detected, its expression level was higher in females with the HoP phenotype compared to females with the HerP phenotype (p < 0.001). In patients with the HoP phenotype, females had higher expression of ACE2 mRNA than males (p < 0.05). In the male study group, ACE protein levels were significantly lower in the HoP phenotype compared to the HerP phenotype (p < 0.001). Fe-males with the HoP phenotype had significantly higher ACE protein levels than males with the HoP phenotype (p < 0.0001). Conclusion. Our results revealed alterations in the expression levels of ACE and ACE2, at the mRNA and protein levels, in advanced carotid As. These alterations are impacted by sex and PP and may indicate a switch from the balanced RAS/ACE/ACE2 axis in the healthy blood vessel to the unbalanced axis in vascular remodeling due to As.Renin-angiotenzin sistem (RAS) povezan je sa
razvojem ateroskleroze (As), ukljuÄujuÄi njen nastanak i
progresiju. Pored dobro poznatog angiotenzinkonvertujuÄeg enzima (angiotensin-converting enzyme ā ACE),
dva nova Älana RAS familije povezana su sa
remodelovanjem zidova krvnih sudova ā ACE2 kao
homolog ACE i kolektrin [transmembrane protein 27
(TMEM27)] kao homolog ACE2. Do sada je mali broj
studija ispitivao ekspresiju komponenti RAS sistema u tkivu
uznapredovalog karotidnog plaka (KP) u odnosu na pol
bolesnika i fenotip plaka (FP). Postoje dva tipa KP
definisana primenom ultrazvuka ā fenotip hipoehogenog
plaka (HoP) i fenotip hiperehogenog plaka (HerP). Cilj rada
bio je da se ispita da li postoji korelacija izmeÄu ekspresije
komponenti RAS u KP i pola i FP bolesnika. Metode.
Ispitano je 74 bolesnika sa uznapredovalim KP koji su bili
podvrgnuti operativnoj proceduri karotidne
endarterektomije. Ekspresija komponenti RAS sistema u
tkivu plaka utvrÄena je lanÄanom reakcijom polimeraze u
realnom vremenu (real-time polymerase chain reaction)primenom eseja TaqManĀ® tehnologije i metode Western blota. Dvosmerna analiza varijanse i Tukey post-hoc test koriÅ”Äen su za statistiÄku obradu rezultata. Rezultati. Nije utvrÄena
interakcija FP i pola bolesnika u uticaju na relativnu
ekspresiju informacione RNK (iRNK) za ACE i TMEM27
(p > 0,05). U 56,06% uzoraka plaka nije detektovana
ekspresija iRNK za ACE2. U plakovima u kojima je
detektovana ekspresija iRNK za ACE2, njen nivo bio je viŔi
kod žena sa HoP u poreÄenju sa ženama sa HerP (p <
0,001). U grupi bolesnika sa fenotipom HoP, žene su imale
viŔi nivo iRNK za ACE2 nego muŔkarci (p < 0,05). U grupi
muÅ”karaca, nivoi ekspresije ACE proteina bili suznaÄajno
niži u fenotipu HoP u poreÄenju sa HerP (p < 0,001). Žene
sa fenotipom HoP imale su znaÄajno viÅ”i nivo ACE
proteina u poreÄenju sa muÅ”karcima sa HoP (p < 0,0001).
ZakljuÄak. NaÅ”i rezultati pokazali su da postoje promene
nivoa ekspresije ACE i ACE2, na nivou proteina i iRNK u
uznapredovaloj karotidnoj As. Te promene zavise od pola i
FP i mogu ukazivati na to da balans ose RAS/ACE/ACE2
koji postoji u zdravom krvnom sudu postaje poremeÄen
tokom remodelovanja zida krvnog suda usled As
Endovascular aortic repair: First twenty years
Endovascular aortic/aneurysm repair (EVAR) was introduced into clinical practice at the beginning of the nineties. Its fast development had a great influence on clinicians, vascular surgeons and interventional radiologists, educational curriculums, patients, industry and medical insurance. The aim of this paper is to present the contribution of clinicians and industry to the development and advancement of endovascular aortic repair over the last 20 years. This review article presents the development of EVAR by focusing on the contribution of physicians, surgeons and interventional radiologists in the creation of the new field of vascular surgery termed hybrid vascular surgery, and also the contribution of technological advancement by a significant help of industrial representatives ā engineers and their counselors. This article also analyzes studies conducted in order to compare the successfulness of EVAR with up-to-now applied open surgical repair of aortic aneurysms, and some treatment techniques of other aortic diseases. During the first two decades of its development the EVAR method was rapidly progressing and was adopted concurrently with the expansion of technology. Owing to large randomized studies, early and long-term results indicate specific complications of this method, thus influencing further technological improvement and defining risk patients groups in whom the use of the technique should be avoided. Good results are insured only in centers, specialized in vascular surgery, which have on their disposal adequate conditions for solving all complications associated with this method
Software and Hardware Systems for Abdominal Aortic Aneurysm Mechanical Properties Investigation
The main goal of this paper is to describe two different systems that were developed for the purpose of abdominal aortic aneurysm mechanical properties investigation and to present the results of the measurements. The first system is based on the "Bubble Inflated" method and it increases the pressure of physiological saline which affects blood vessel tissue and causes mechanical deformation. The system provides recording the data about the current value of the pressure in the physiological saline by using the appropriate pressure sensor. The second system makes stretches of the vessel tissue in uni-axial direction and save the data about the force and the elongation. Both of these systems use cameras for assessment of the deformation. Obtained results from both systems are used for numerical simulation of computer model for abdominal aortic aneurysm. It gives a new avenue for application of software and hardware systems for determination of vascular tissue properties in the clinical practice
Role of recombinant factor VIIa in the treatment of intractable bleeding in vascular surgery
BackgroundMost recent publications have shown that the recombinant form of activated factor VII (rFVIIa; NovoSeven, Novo Nordisk A/S, BagsvƦrd, Denmark) induces excellent hemostasis in patients with severe intractable bleeding caused by trauma and major surgery. The purpose of this study was to determine the influence of rFVIIa on the treatment of intractable perioperative bleeding in vascular surgery when conventional hemostatic measures are inadequate.Materials and MethodsThere were two groups of patients: the NovoSeven group (group N), 10 patients with ruptured abdominal aortic aneurysms (RAAAs) and 14 patients operated on due to thoracoabdominal aortic aneurysms (TAAAs); the control group (group C), 14 patients with RAAAs and 17 patients with TAAAs. All patients suffered intractable hemorrhage refractory to conventional hemostatic measures, while patients from group N were additionally treated with rFVIIa.ResultsPostoperative blood loss was significantly lower in group N treated with rFVII (P < .0001). Postoperative administration of packed red blood cells, fresh frozen plasma, and platelets was lower in patients from group N, (P < .0001). Successful hemorrhage arrest was reported in 21 patients (87.5%) treated with rFVIIa, and in 9 patients (29.03%) in group C (P < .001). Thirty-day mortality in these two groups significantly differed. The mortality rate was 12.5% (3 patients) in group N and 80.65% (25 patients) in group C (P < .0001).ConclusionOur findings suggest that rFVIIa may play a role in controlling the intractable perioperative and postoperative bleeding in surgical patients undergoing a repair of RAAAs and TAAAs. Certainly, prospective randomized trials are necessary to further confirm the efficacy and cost-effectiveness of rFVIIa in these patients
Polymorphism rs10757278 in 9p21 region is associated with severe carotid atherosclerosis in sex specific manner: Preliminary results
Genome wide association studies have recognized the 9p21 rs10757278 polymorphism as a significant independent genetic prognostic marker for coronary artery disease. The aim of this study was to explore possible association of the rs10757278 polymorphism with advanced carotid atherosclerosis (CA) in the population of Serbia. The study group included 147 controls and 428 patients consecutively admitted for carotid endarterectomy. 9p21 rs10757278 polymorphism was genotyped using TaqMan technology on 7500 ABI Real Time PCR. There was no significant association of this polymorphism and CA, either in study group overall or in males. The GG genotype, according to recessive model of inheritance (AA+AG vs. GG), was significantly associated with advanced CA in females only (OR=2.15, 95% CI 1.07- 4.29, p=0.03). Preliminary results in this study suggest that rs10757278 GG genotype might be a significant predictive sex-specific marker for advanced CA in the population of Serbia.5th Congress of the Serbian Genetic Society : Book of abstracts; September 28 - October 2, Kladovo, 2014
The association of ACE I/D gene polymorphism with severe carotid atherosclerosis in patients undergoing carotid endarterectomy
Introduction: The ACE I/D polymorphism was mostly investigated in association with intima-media thickness, rarely with severe atherosclerotic phenotype. Materials and methods: We investigated the association of I/D polymorphism with severe carotid atherosclerosis (CA) (stenosis GT 70%) in asymptomatic and symptomatic patients undergoing carotid endarterectomy. The 504 patients subjected to endarterectomy and 492 healthy controls from a population in Serbia were investigated as a case-control study. Results: The univariate logistic regression analysis revealed ACE DD as a significant risk factor for severe CA (odds ratio [OR] = 1.3, 95% confidence interval [CI] 1.0-1.7, p = 0.04). After adjustment for the common risk factors (age, hypertension, smoking, and HDL) ACE was no longer significant. However, we found a significant independent influence of DD genotype on plaque presence in a normotensive subgroup of patients (OR 1.8, CI 1.2-3.0, p = 0.01, corrected for multiple testing). In symptomatic patients D allele carriers were significantly more frequent compared with asymptomatic patients (OR 1.6 CI 1.0-2.6, p = 0.05). Conclusions: Our data suggests that ACE I/D is not an independent risk factor for severe CA. On the other hand, a significant independent genetic influence of ACE I/D appeared in normotensive and symptomatic patients with severe CA. This should be considered in further research toward resolving the complex genetic background of severe CA phenotype
Determination of biomechanical, anatomical and patophysiological factors influencing wall strength of the abdominal aortic aneurysm and their role in the abdominal aortic aneurysm rupture risk assessment
Uvod. Aneurizma abdominalne aorte je potencijalno fatalno oboljenje koje se preventivno
može leÄiti hirurÅ”ki. Rizik od hirurÅ”kog leÄenja je sve manji meÄutim ma koliko bile retke
komplikacije mogu biti fatalne ili prouzrokovati težak invaliditet. Upravo zato je od velikog
znaÄaja poznavanje rizika od rutpure aeurizme koji se trenutno procenjuje samo na osnovu
najveÄeg preÄnika aneurizme Å”to se pokazuje kao nedovoljno precizno. Ispitivanje uticaja
drugih parametara (biomehaniÄkih, anatomskih, patomorfoloÅ”kih) na nastanak rupture bi
moglo da napredi procenu rizika od ove fatalne komplikacije.
Metod. Ispitivanje je sprovedeno po tipu prospektivne studije koja je obuhvatila 288 bolesnika
sa aneurizmom abdominalne aorte koji su ispitivani ili operisani na Klinici za vaskularnu i
endovaskularnu hirurgiju KCS u periodu od januara 2012 do decembra 2015 godine. Na osnovu
podataka dobijenih multislajsnom kompjuterizovanom tomografijom kod bolesnika su
ispitivani biomehaniÄki parametri koji deluju na zid aneurizme (napon, preÄnik ekvivalentan
riziku od rupture) kao i morfoloki parametri koji bi mogli da ukažu na patofizioloŔke procese
u aneurizmatskoj kesi (zapreminu aneurizme, intraluminalnog tromba, angulacije). Uzorci
prednjeg zida aneurizmatske kese ispitivani su testom inflacije i na taj naÄin im je odreÄivana
snaga i elastiÄnost dok je iz uzorka seruma odreživana aktivnost matriksne metaloproteinaze 9.
Rezultati. ZnaÄajno viÅ”e osoba ženskog pola je bilo u grupi bolesnika sa simptomatskom
odnosno rupturiranom aneurizmom abdominalne aorte, 5/23 (21.73%) prema 12/75 (16%),
p=0.005. Multivarijantni model kojim su ukljuÄeni pol, životna dob, maksimalni preÄnik
aneurizme (MAD,OR=1.063), relativna zapremina intraluminalnog tromba (rILT, OR=1.039)
i ukupna zapremina aneurizme (UZA,OR=1.006) su znaÄajni prediktori rupture aneurizme
abdominalne aorte sa najveÄim naponom u zidu (PWS,OR=1.010) dijametra ekvivalentan
riziku od rupture (RRED,OR=1.031). Merene su vrednosti AUC i cc za iste parametre u modelu
koji kombinuje MAD, TZA i rILT: MAD (0.790, cc=75%), PWS (0.713, cc=73%), RRED
(0.717, cc=55%), TAV (0.756, cc=79%), rILT (0.656, cc=60%) i MAD+TAV+rILT (0.797,
cc=82%). Nije dobijena statistiÄki znaÄajna razlika izmeÄu vrednosti serumske MMP 9 i snage
zida, test korelacije je iznosio 0.174, p=0.135. Konstatovana je statistiÄki znaÄajna povezanost
izmeÄu serumske koncentracije MMP 9 i srednjeg napona u intraluminalnom trombu (cc -
0.371, p=0.016), najveÄeg rizika od rupture (p=0.04) i volumena intraluminalnog tromba (cc
0.324, p=0.03).
ZakljuÄak. ImajuÄi u vidu zadate ciljeve kao i prikazane rezultate može se zakljuÄiti da je zid
aneurizme abdominalne aorte slabije snage kod aneurizmi koje su veÄ rupturirale ili izazivale
simptome Äime je pokazano da snaga zida ima važnu ulogu u procesu nastanka rupture. Na
snagu aneurizmatskog zida je uticala jedino relativna debljina intraluminalnog tromba.
Serumska koncetracija MMP ā 9 se, prema rezultatima ovog istraživanja, ne može koristiti za
procenu snage aneurizmatskog tkiva prilikom predviÄanja rizika od rupture aneurizme
abdominalne aorte. BiomehaniÄki, anatomski odnosno morfoloÅ”ki parametri mogu zaÄajno
unaprediti predviÄanje rizika od rupture u odnosu na koriÅ”Äenje samog dijametra. Najkorisniji
su najveÄi napon, zapremina aneurizme, relativna zapremina intraluminalnog tromba i
dijametar ekvivalentan riziku od rupture. KoriÅ”Äenjem ovih parametara moÄ predviÄanja
nastanka rupture se poveÄava sa 73% na 83.9%.Introduction. Abdominal aortic aneurysm is potentialy fatal disease that can be treated with
preventive operation. Surgical risk, although improving, can lead to death or disability. In this
regard it is of high importance to assess risk of rupture that is nowdays expressed in correlation
to aneurysm diameter what was shown to be less accurate. Assessment of correlation between
other parameters (biomechanical, anatomical, patomorphological) and risk of aneurysm rupture
might improve rupture risk assesment and facilitate decision making.
Methods. This research was conducted in prospective manner at the Clinic for Vascular and
Endovascular surgery and included 288 patients with abdominal aortic aneurysm in the period
from January 2012 to December 2015. Images from multisliced computed tomography were
used for biomechanical analysys to estimate peak wall stress and rupture risk equvivalent
diameter by finite element analysys. Morphological parameters as aneurysm and intraluminal
thrombus volume, angulations and anatomical parmeters were assessed from these images as
well. Samples of anterior wall of aneurysm were tested with inflation test estimating tissue
elasticity and strength while serum level of matrix metalloproteinase 9 were measured as well.
Results. There were significantly more females in the R group: 5/23 (21.73%) comparing to
12/75 (16%) in 4A group, p=0.005. In a multivariable model, including gender and age as
confounder variables, maximal aneurysm diameter (MAD,OR= 1.063), relative intraluminal
thrombus (rILT,OR=1.039) and total aneurysm (TAV,OR=1.006) volume continued to be a
significant predictors of AAA rupture with peak wall stress (PWS,OR=1.010) and rupture risk
equivalent diameter (RRED,OR=1.031). AUC values and correct classification (cc) for the
same parameters and model that combines MAD, TAV and rILT were measured: MAD
(0.790, cc=75%), PWS (0.713, cc=73%), RRED (0.717, cc=55%), TAV (0.756, cc=79%),
rILT (0.656, cc=60%) and MAD+TAV+rILT (0.797, cc=82%)
Conclusion. Based on aim and presented results aneurysm wall is weaker in ruptured and
symptomatic aneurysm outlining importance of wall strength in rupture developement. Wall
strength correlated with relative thrombus thickness. Serum level of MMP-9, based on these
restults, can not be used for tissue strength assessment however thrombus formation can be
suspected in elevated levels of MMP 9. Biomechanical, anatomical and moprhological
paramters can improve rupture prediction in comparison to maximal diameter only. The most
usefull paramters are peak wall stress, aneurysm volume, relative intraluminal thrombus and
rupture risk equivalent diameter. Using these paramters rupture prediction is increased from
73% to 83.9%