Vascular Variations Associated with Intracranial Aneurysms

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1 DOI: / JTN Received: / Accepted: Pulished Online: Originl Investigtion Vsculr Vritions Associted with Intrcrnil Aneurysms Metin ORAKDOGEN 1, Selin Turl EMON 1, Hkn SOMAY 1, Tner ENGIN 1, Merih IS 1, Tyfun HAKAN 2,3 1 Hydrps Numune Teching nd Reserch Hospitl, Neurosurgery Clinic, Istnul, Turkey 2 Koln Interntionl Hospitl, Neurosurgery Clinic, Istnul, Turkey 3 Okn University, Voctionl School of Helth Services, Istnul, Turkey Prts of this study were presented in strct/orl presenttion form t the 29 th Annul Scientific Congress of Turkish Neurosurgicl Society, Antly, Turkey, April, 17-21, ABSTRACT AIm: To investigte the vsculr vritions in ptients with intrcrnil neurysm in circle of Willis. MterIl nd Methods: We used the dt on 128 consecutive intrcrnil neurysm cses. Cererl ngiogrphy imges were nlyzed retrospectively. Arteries were grouped s nterior cererl rteril system (ACS), posterior cererl rteril system (PCS) nd middle cererl rteril system (MCS) for grouping vsculr vritions. Lterliztion, eing single/multiple, gender; nd lso ny connection with ccompnying neurysms numer, locliztion, dimension, whether leeding/incidentl neurysm hs een inspected. Results: Vritions were demonstrted in 57.8% of the cses. The most common vrition ws A1 vrition (34.4%). The rte of vritions ws 36.7%, 24.2% nd 10.2% respectively in ACS, PCS nd MCS. MCS vritions were significntly higher in mles. Anterior communicting rtery (ACoA) neurysm oservnce rtes were significntly higher nd posterior communicting rtery (PCoA) neurysm nd middle cererl rtery (MCA) neurysm oservnce rtes were significntly lower when compred to no ACS vrition detected cses. In PCS vrition detected cses, PCoA neurysm oservnce rtes nd coexistence of multiple vritions were significntly higher. ConclusIon: The rte of vsculr vritions in ptients with neurysms ws 57.8%. Arteril hypoplsi nd plsi were the most common vritions. ACS ws the most common region tht vritions were locted in; they were mostly detected on the right side. Coexistence of ACoA neurysm ws higher thn PCoA nd MCA neurysms. In the PCS vritions group, PCoA neurysms were the most common neurysms tht ccompnying the vrition nd multiple vritions were more common thn in the other two groups. The vritions in MCS were most common in mles. Keywords: Aplsi, Cererl neurysm, Vsculr vrition, Circle of Willis, Hypoplsi, Microsurgicl ntomy INTRODUCTION The crotid nd verterosilr systems re connected to ech other y polygonl nstomosis chnnel system tht is clled circulus rteriosus t the se of the rin. Although Thoms Willis mde the first ttempt to ttriute function to this ntomy tht he descried in 1664; his description of the rin ecme ccepted s definitive, ppering in the Biliothec Antomic of for the first time s the fmous circle of Willis in the eighteenth century (25). Clssiclly, symmetricl nd complete Willis pttern ccounts for only 30-50% of individuls in the popultion (1,8,10,27). The rteries constituting it my show different vritions depending on their hypoplsi, plsi nd fenestrtion, dupliction, trifurction. These vritions my ply considerle role in the development of n neurysm, Corresponding uthor: Tyfun HAKAN E-mil: tyfunhkn@yhoo.com Turk Neurosurg 27(6): ,

2 Orkdogen M. et l: Vsculr Vritions nd Intrcrnil Aneurysms rteriovenous mlformtion or cererovsculr occlusive disese y chnging the lood-flow pttern nd incresing hemodynmic stress (3,4,7,12,13,15,23,26,29). There re some reports tht hve investigted the reltionship etween vritions nd neurysm locliztion in cdveric (12,20,28) nd clinicl studies (14,18,22,31). The im of this study ws to revel the norml pttern nd vrition rtes in series of ptients operted for intrcrnil neurysms nd show these vritions gender, locliztion, lterliztion, multiplicity fetures esides their reltionship with neurysms in severl loctions, whether leeding or incidentlly dignosed. MATERIAL nd METHODS The study ws crried out in totl of 128 consecutive neurysm cses operted t Hydrpş Numune Teching nd Reserch Hospitl etween the yers 2008 nd Cererl digitl sutrction ngiogrphy (DSA) imges of ech ptient nd the detiled reports written y neurordiologists were nlyzed retrospectively y two neurosurgeons who prcticed neurovsculr surgery. Associted vsculr vritions of the nterior cererl, posterior cererl nd middle cererl rteril system were grouped nd studied morphologiclly: 1) Anterior cererl rtery (ACA) nd its rnches were ssumed s the nterior cererl rteril system (ACS) 2) Verterl rtery nd its rnches were ssumed s the posterior cererl rteril system (PCS) 3) Middle cererl rtery (MCA) nd its rnches were ssumed s the middle cererl rteril system (MCS). Vsculr vritions such s hypoplsi, plsi (sence), dupliction, fenestrtion, trifurction were noted nd lterliztion, single or multiple, gender ssocitions nd numer of neurysms, locliztion, dimeter, incidentl or leeding neurysm coexistence with these vsculr vritions were serched for. A vrition of the circle of Willis ws regrded s congenitl normlities (5,22). Arteries with externl dimeter less thn 1 mm nd communicting rteries smller thn 0.5 mm were ccepted s hypoplstic nd the sence of the rtery s plstic (1,6,20,28). The posterior cererl rtery (PCA) segment of Willis polygon ws defined s fetl type nd dult type ccording to its size. When visulized P1 on DSA hd smller size thn ipsilterl posterior communicting rtery (PCoA) or totlly sent, it ws ccepted s fetl-type origin of PCA; nd P1 segment hd the sme size s or lrger size thn PCoA ws defined s dult type origin of PCA (15). Sttisticl Anlyses The Numer Cruncher Sttisticl System (NCSS) 2007 & Power Anlysis nd Smple Size (PASS) 2008 Sttisticl Softwre (Uth, USA) progrms hve een used for sttisticl nlysis. The Mnn-Whitney U test ws used for descriptive sttisticl methods (Men, Stndrd Devition, Medin, Frequency, Rte, Minimum, Mximum) nd in compring quntittive dt tht did not show norml rnge/distriution. The Person Chi-Squre test, Fisher s Exct test nd Ytes Continuity Correction test (Ytes corrected Chi-Squre) were used for compring qulittive dt. Significnce t level of p<0.01 nd p<0.05 ws otined. RESULTS The study ws crried out on totl of 128 consecutive ptients with intrcrnil neurysms. The numers of incidentl nd leeding cses were 17.2% (n=22) nd 82.8% (n=106), respectively. The ptients included 55 (43%) men nd 73 (57%) women who rnged in ge from 16 to 81 yers (men=52.35±12.38 yers). Among ll cses, 95 (74.2%) hd single neurysm nd 33 (25.8%) hd multiple neurysms. Vsculr vritions were demonstrted in 57.8% (n=74) of the cses. Vritions were single in 40.6% (n=52) of the cses. There were 2 vritions in 18 cses nd 3 vritions in 4 cses. Gender The differences etween vrition oservnce rtes (p=0.426; p>0.05) nd vrition numer rtes (p=0.083; p>0.05) y gender were not sttisticlly significnt. However, MCS vrition oservnce rtes were significntly higher in mles thn femles (p=0.031; p<0.05) (Tle I). ACS Vritions ACS vrition ws the most frequent occurrence for 36.7% (n=47) of the cses. The most common vrition ws A1 vrition with 44 (34.4%) cses: 33 hd hypoplsi nd 11 plsi. Others were nterior communicting rtery (ACoA) fenestrtion, ilterl pericllosl hypoplsi, nd left cllosomrginl plsi. Thirty-one of these cses hd single nd 16 hd multiple vritions. The vritions were right-sided in 30 (68.2 %) cses nd left-sided in 14 (31.8%) (Figure 1A- D). Right-side ACS vritions were twice s frequent s those on the left side; 62.8% of A1 hypoplsi-plsi vritions were on the right side nd 31.8% were on the left side. A1 vritions were hypoplsi in 33 cses nd plsi in 11 cses. The ACS vrition rte nd ACoA neurysm coexistence were significntly higher (p=0.001; p<0.01) (Tle II). Aprt from 5 internl crotid rtery (ICA) ifurction neurysms, there were n dditionl 6 ICA neurysms. Three of them were ophthlmic neurysms, 1 ws superior hypophysel neurysm, 1 ws prclinoid neurysm nd 1 ws n ICA wll neurysm. In these cses, the vrition rtes were significntly lower (p=0.005; p<0.01). PCS Vritions PCS vrition ws oserved in 31 (24.2%) cses with 14 single nd 17 multiple vritions. P1 hypoplsi/plsi ws the most common vrition with 28 (21.9%) cses. In this group, 2 hypoplsi nd 1 plsi were detected in verterl rteries. The vritions were right-sided in 12 (38.7%) cses, left-sided 854 Turk Neurosurg 27(6): , 2017

3 Orkdogen M. et l: Vsculr Vritions nd Intrcrnil Aneurysms Tle I: Vrition Rtes ccording to Gender Gender Vrition Numer of vrition (n=74) ACS vrition PCS vrition MCS vrition Person chi squre test, Ytes Continuity Correction, *p<0.05. Mle Femle n (%) n (%) No 21 (38.2) 33 (45.2) Yes 34 (61.8) 40 (54.8) Single vrition 20 (58.8) 32 (80.0) Multiple vrition 14 (41.2) 8 (20.0) No 13 (38.2) 15 (37.5) Yes 21 (61.8) 25 (62.5) No 21 (61.8) 22 (55.0) Yes 13 (38.2) 18 (45.0) No 24 (70.6) 37 (92.5) Yes 10 (29.4) 3 (7.5) p * A B C D Figure 1: DSA exmintion showing exmples of ACS vritions. A) Pericllosl hypoplsi. B) Distl nterior cererl rtery (DACA) neurysm in the DSA exmintion of the sme ptient. C) Right A1 plsi. D) ACoA neurysm tht fills from left crotid system. Turk Neurosurg 27(6): ,

4 Orkdogen M. et l: Vsculr Vritions nd Intrcrnil Aneurysms Tle II: Aneurysm Rtes ccording to ACS Vrition Presence ACS vrition No Yes n (%) n (%) ACoA No 64 (79.0) 13 (27.7) Yes 17 (21.0) 34 (72.3) PCoA No 62 (76.5) 44 (93.6) Yes 19 (23.5) 3 (6.4) MCA No 40 (49.4) 34 (72.3) Yes 41 (50.6) 13 (27.7) ICA ifurction No 74 (91.4) 44 (93.6) Yes 7 (8.6) 3 (6.4) AChoA No 77 (95.1) 45 (95.7) Yes 4 (4.9) 2 (4.3) ICA No 75 (92.6) 47 (100.0) Yes 6 (7.4) 0 (0.0) DACA No 75 (92.6) 46 (97.9) Yes 6 (7.4) 1 (2.1) Ytes Continuity Correction, Fisher s Exct Test, *p<0.05, **p<0.01. p 0.001** 0.026* 0.019* A B C D Figure 2: DSA exmintion showing exmples of PCS vritions. A) Fetl circultion in AP projection (white rrow). B) Fetl circultion in lterl projection (white rrow). C) AP projections showing P1 plsi. D) Accompnying PCoA neurysm in the sme ptient. 856 Turk Neurosurg 27(6): , 2017

5 Orkdogen M. et l: Vsculr Vritions nd Intrcrnil Aneurysms in 13 (42%) cses nd ilterl in 6 (19.3%) cses (Figure 2A- D). PCS vrition rte nd PCoA neurysm coexistence were significntly higher (p=0,023; p<0.05) (Tle III). MCS Vritions MCS vritions were seen in 13 (10.2%) cses; 8 were single nd 5 were multiple. One-sided or ilterl MCA trifurction ws the most common vrition with 9 (7%) cses. Others were MCA trifurction nd erly ifurction, erly ifurction, MCA dupliction, nd M2 superior trunk hypoplsi. The vritions were right-sided in 4 (30.8%) cses, left-sided in 7 (53.8%) cses nd ilterl in 2 (15.4%) cses (Figures 3A,B; 4A,B) Tle III: Aneurysm Rtes ccording to PCS Vrition Presence PCS vrition No Yes n (%) n (%) ACoA No 60 (61.9) 17 (54.8) Yes 37 (38.1) 14 (45.2) PCoA No 85 (87.6) 21 (67.7) Yes 12 (12.4) 10 (32.3) MCA No 53 (54.6) 21 (67.7) Yes 44 (45.4) 10 (32.3) ICA ifurction No 89 (91.8) 29 (93.5) Yes 8 (8.2) 2 (6.5) AChoA No 93 (95.9) 29 (93.5) Yes 4 (4.1) 2 (6.5) ICA No 91 (93.8) ) Yes 6 (6.2) 0 (0.0) DACA No 90 (92.8) 31 (100.0) Yes 7 (7.2) 0 (0.0) Ytes Continuity Correction, Fisher s Exct Test, * p<0,05. p * A B Figure 3: DSA exmintion showing exmples of MCS vritions. A) M1 dupliction (lck rrow). B) MCA neurysm (lck rrow) with trifurction (right). Turk Neurosurg 27(6): ,

6 Orkdogen M. et l: Vsculr Vritions nd Intrcrnil Aneurysms Tle IV: Aneurysm Rtes ccording to MCS Vrition Presence MCS vrition No Yes n (%) n (%) ACoA No 68 (59.1) 9 (69.2) Yes 47 (40.9) 4 (30.8) PCoA No 93 (80.9) 13 (100.0) Yes 22 (19.1) 0 (0.0) MCA No 69 (60.0) 5 (38.5) Yes 46 (40.0) 8 (61.5) ICA ifurction No 105 (91.3) 13 (100.0) Yes 10 (8.7) 0 (0.0) AChoA No 109 (94.8) 13 (100.0) Yes 6 (5.2) 0 (0.0) ICA No 109 (94.8) 13 (100.0) Yes 6 (5.2) 0 (0.0) DACA No 109 (94.8) 12 (92.3) Yes 6 (5.2) 1 (7.7) Ytes Continuity Correction, Fisher s Exct Test. p A B Figure 4: DSA exmintion showing exmples of multiple vritions. A) Right MCA trifurction nd A1 plsi. B) Fetl circultion nd A1 plsi. 858 Turk Neurosurg 27(6): , 2017

7 Orkdogen M. et l: Vsculr Vritions nd Intrcrnil Aneurysms MCS vrition rte nd neurysm coexistence showed no sttisticlly significnt difference in ny locliztion (Tle IV). Multiple Vritions The rtes of single nd multiple nomlies were 24% nd 28%, respectively. There were two nomlies in 20% of the cses nd more thn two nomlies in 8% of the cses. Multiple vrition rtes were significntly higher in PCS cses (p=0.001; p<0.01) (Tle V). Bleeding & Non-leeding Aneurysm, Numer nd Locliztion of Aneurysm The vsculr vritions were more common in leeding neurysms (61.3% versus 40.9%). The rte of multiple vritions ws lso higher in leeding neurysms (18.9% versus 9.1%). There ws no significnt difference, either in vrile rtes (p=0.127; p>0.05) or in the numer of vritions (p=0.716; p>0.05), etween leeding/non-leeding cses. According to the neurysm numer, vrition rtes (p=0.291; p>0.05) nd vrition numer rtes (p=0.364; p>0.05) were not sttisticlly significntly relted. In single neurysm cses, there ws no sttisticlly significnt difference etween cses relted with the neurysm dimeter (p=0.659; p>0.05). There ws no sttisticlly significnce etween the neurysm nd numer vrition rtes in ny locliztion (p>0.05). In single or multiple vrition cses, there ws no ICA neurysm presence. DISCUSSION Incidence In the present study, the overll rte of vritions in the circle of Willis configurtion with erry neurysms ws 57.8%. The rte of vritions in series with ccompnying intrcrnil neurysms ws etween 40.7% nd 97% (2,12,20,27,32,33). In recent cdveric study conducted on the Turkish popultion, dult configurtion of the polygon ws detected in 87% (11). In cdveric rins with unknown cuse of deth, Gunnl et l. (6) found gross morphologicl vritions in 40% of the cses. Kpoor et l. (10) reported vritions in 54.8% of 1000 medicl utopsies. Qiu et l. (27) found the incidence of prtil integrity nd non-integrity s 70.17% nd 17.59% respectively in 2,146 helthy sujects tht were exmined with mgnetic resonnce imging (MRI) nd mgnetic resonnce ngiogrphy (MRA). Vritions We found tht the most common nomly ws hypoplsi in the Willis polygon, similr to other series (1,6,8,9,29). It ws mostly seen in the A1 segment, followed y the P1 segment. Aplstic/hypoplstic A1 ws lso the most common vrition in some reports (17,33). The incidence of hypoplstic nd plstic A1 segment of the nterior cererl rtery ws reported s 36% y Kryzewski et l. (16). In n MRI study investigting nterior cererl rtery vritions, the A1 segment plsi rte ws only 5.6% (36). The fenestrtion of the A1 nd/or A2 segment ws found to e 1.2%. Kovc et l. (13) reported tht the ptients hd hypoplstic or congenitl sence of A1 segment t rte of 17.6% nd 0.4%, respectively. Fetl origin of the posterior cererl rtery ws found in 37% of the cses. In their series, Iql et l. (8) stted hypoplsi in PCoA rte of 24% tht ws followed y hypoplsi in the P1, A1 nd ACoA segments. Similrly, Krts et l. (11) found hypoplsi most commonly in the PCoA. The hypoplsi of A1 ws frequently ssocited with ACoA neurysms nd this is comptile with our results (26). Although we detected only one fenestrtion in this study, Suziki et l. (34) reported 75% fenestrtion in 38 cses of ACA neurysms in their surgicl series. Two-dimensionl imges re thought to e unsuitle for detecting intrcrnil rteril fenestrtions ecuse of superimposition of vessels tht my render their identifiction (17,34). In recent study, including ptients with surchnoid hemorrhge, vn Rooij et l.(39) found 24% fenestrtion y 3D rottionl ngiogrphy. In study with CT ngiogrphy, the fenestrtions of middle cererl rtery M1 segment (0.2%), nterior communicting rtery (0.4%), nd nterior cererl rtery A1 segment (0.6%) Tle V: ACS, PCS nd MCS Vrition Rtes ccording to the Numer of Aneurysms Numer of vritions Single vrition Multiple vrition n (%) n (%) ACS vrition No 21 (77.8) 6 (22.2) Yes 31 (66.0) 16 (34.0) PCS vrition No 38 (88.4) 5 (11.6) Yes 14 (45.2) 17 (54.8) MCS vrition No 44 (72.1) 17 (27.9) Yes 8 (61.5) 5 (38.5) Ytes Continuity Correction, Fisher. p ** Turk Neurosurg 27(6): ,

8 Orkdogen M. et l: Vsculr Vritions nd Intrcrnil Aneurysms were lso noted (13). Fenestrtion my e seen even in the A2 segment of the nterior cererl rtery (4). Kryenuhl nd Yşrgil (15) reported verterl rtery fenestrtion or nomlous termintion. Gunnl et l. (7) found morphologicl vritions in termintion in 17.64% of the cses. The prevlence of fenestrtions of the intrcrnil VB system ws reported to e etween 1.17% nd 2.77% (7,13,37). We detected P1 hypoplsi/plsi in 28% of the cses in the presented study. Iql et l.(8) reported 10% vrition rte for fetl PCA. Gunnl et l.(6) found tht the most common vrition rte ws in the PCoA with 50%, followed y ACoA with 33.3%. Mlmteniou et l. (21) stted tht the most common vrition ws PCoA plsi (30%) in the neontl group. Seki nd Rhoton (30) reported tht PCoA hypoplsi ws unilterl in 26% of the cses nd ilterl in 6% of the cses. The rte of fetl configurtion in which the PCA ws rising predominntly from the crotid rtery ws 20% nd 2% for unilterlly nd ilterlly respectively. Ysrgil (40) reported tht the rte of the fetl type of circultion ws 24.5% with much greter frequency on the right. Qiu et l. (27) demonstrted n incidence of 15.85% for P1 vrition. Gio et l. (5) found tht MCA nomlies re less common thn the other nomlies consisting of duplicte or ccessory MCA. They oserved MCA trifurction in 12% of the cses. This ws similr to our study; MCA nomlies were the lest common with 10.2% nd, trifurction ws the most common vrition with 7%. Vrition & Numer, Locliztion of Aneurysm Some specific neurysms cn e encountered together with some vritions. Although ACA vritions were seen commonly with ACoA neurysms (p<0.01) in this study, there ws no vrition in 6 ICA neurysm cses nd this ws sttisticlly significnt (p<0.01). A1 segment vritions hve een reported more frequently in ACoA neurysm cses thn in the control group (14,28). Suzuki et l. (34) reported 75% nd Vn Rooij et l. (39) reported 31% fenestrtion of ACoA tht ccompnied the neurysm. In study tht investigted ntomic vritions nd recurrence rtes of ptients undergoing coil-emoliztion with neurysms, A1 dominnce on one side with ACoA neurysms ws found to e 73%. A1 dominnt flow ws shown to ct in neurysm formtion, growth nd instility fter coil emoliztion tretment (35). Kryzewski et l. (16) suggested tht A1 nd A2 segment nomlies of the nterior cererl rtery my potentilly e ssocited with neurysm formtion. Although the clinicl significnce of ACA vritions is usully minor, n ssocited neurysm is found reltively frequently (36). Songseng et l. (31) reported more frequent ACoA, PCoA nd BA neurysm coincidence with A1 plsi nd fetl PCoA. Notly, symmetricl A1 segment nd symmetricl silr pex presence were ssocited with recurrence following coil emoliztion. There ws n inverse reltion for PCoA nd MCA neurysms. In ACS vritions, PCoA nd MCA neurysm coexistence (p<0.05) ws significntly lower thn in cses without ACS vrition. There ws no sttisticlly significnt difference etween other neurysm locliztions nd nterior system vrition presence. Mcchi et l. (19) proposed tht ntomic vrition rtes were higher in the left side, ut we found higher vrition rte on the right side in the ACS group. Stojnovic et l. (33) reported Willis symmetry prevlence of 64% in their series; in multiple neurysms this rte incresed to 75.7%. It ws found to e 61.1% nd 48.5% for ccompnying single nd multiple neurysms respectively in the present study ut there ws no sttisticl significnce. Mzighi et l. (22) reported tht vsculr nomlies were ssocited with neurysm development nd leeding. Vsculr nomlies were found in 88% of the ptients with multiple intrcrnil neurysms. The most common nomly ws the symmetric cudl silr fusion (43.2%) followed y vritions of the nterior communicting rtery (ACoA) complex (31.2%). The neurysm led proportionlly more frequently when ssocited with the relted vsculr nomly (22). Nurminen et l. (24) found mjor ntomic vritions ffecting cererl rteries in 2% of the ptients with gint intrcrnil neurysms. Willis vritions were encountered frequently, prticulrly in ACoA nd PCoA neurysms (5,12,14,20). Asymmetricl A1 nd ACoA neurysms show this ssocition, s well s symmetricl PCoA nd PCoA neurysms. The ssocition etween vrition nd neurysm locliztion supports the role of hemodynmic fctors in the pthogenesis. In severl neurysm cses, more thn one vrition cn e oserved (12). In our study, single vrition ws oserved in 40.6% of the cses; the rte ws 17.2% for multiple vritions. Multiple vritions were 2 in numer in 18 cses, nd 3 in 4 cses. Bleeding & Non-Bleeding Aneurysms High Willis symmetry rtes in leeding neurysms confirm the reltionship etween hemodynmic disturnce due to symmetric configurtion nd neurysm formtion nd rupture (3,4,7,12,13,15,23,26,29,33). In leeding ACoA neurysms, Stojnovic et l. (33) reported tht the symmetry presence ccounted for 72.7%; morphologicl chnges were present in the A1 segment (44%) nd minly on the right side (60%). Lzzro et l. (18) found the Willis nomly in 46.9% of leeding neurysms nd 29.6% of non-leeding (incidentl) neurysms, nd proposed tht neurysm rupture rtes were higher in the presence of Willis nomly. They stted tht the Willis nomly ws more common in leeding nterior nd posterior communicting rtery neurysms thn in non-leeding neurysms. Vn Rooij et l. (39) reported 31% fenestrtion of ACoA where n ccompnying neurysm cused SAH. In the present study, comptile with Lzzro et l. (18), vrition presence ws more common in leeding neurysm cses thn in non-leeding neurysm cses t 61.3% nd 40.9% respectively. The multiple vrition rte ws higher in leeding neurysms t 18.9% versus 9.1%. However, there 860 Turk Neurosurg 27(6): , 2017

9 Orkdogen M. et l: Vsculr Vritions nd Intrcrnil Aneurysms ws no significnt difference etween leeding/non-leeding cses on sttisticl nlysis, either in the vrile rtes (p=0.127; p>0.05) or in the numer of vritions (p=0.716; p>0.05). Gender Reltionship Vn Overeeke et l. (38) reported no significnt frequency difference regrding gender or right-left side in the dult or fetl configurtion in fetl nd infnt rins. They noted tht vritions occur s developmentl modifictions more thn genetic fctors. Mlmteniou et l. (21) found tht complete Willis vrition rtes were higher in preterm girls, nd ACoA nd P1 segment plsi-hypoplsi ws two times higher in term-orn girls, wheres PCoA nd A1 segment plsihypoplsi were more frequent in preterm oys. In term-orn infnts, the fetl type of PCA is twice s frequent in the left side. In the present study, there ws no difference in rtes in the ACS nd PCS groups considering the gender of cses, ut MCA vrition rtes in mles were significntly higher (p=0.031; p<0.05). In contrst, Krzyżewski et l. (16) reported tht mles hd significntly higher prevlence of the typicl ACoA complex. The limittions of this study re s follows: The detected vsculr vritions in this study were ll in ptients who were suject to surchnoid hemorrhge nd/or cererl neurysm. These vritions give no informtion out norml/helthy cses. Cdveric studies my provide more ccurte knowledge out nturl ntomy, ut the im of this pper ws to show the rteril vritions in ptients with n intrcrnil vsculr insult. All the imges re 2-dimensionl, nd 2-dimensionl imges my not e suitle for detecting intrcrnil rteril fenestrtions. CONCLUSION There ws n ssocition etween neurysm locliztion nd vsculr vritions. In the present study, rte of vritions in the circle of Willis configurtion in ptients with erry neurysms ws 57.8%. Arteril hypoplsi nd plsi were the most common vsculr vritions ssocited with intrcrnil neurysms. ACS ws the most common region tht vritions were locted in; they were mostly detected on the right side. In the ACS vritions group, coexistence of ACoA neurysm ws higher thn with PCoA nd MCA neurysms. In the PCS vritions group, PCoA neurysms were the most common neurysms tht ccompnied the vrition. In the PCS vrition group, multiple vritions were more common thn in the other two groups. The vsculr vritions in MCS were most common in mles. Knowledge/wreness of these vritions would guide choosing nd pplying tretment modlities, nd increse the success rte in mnging the ptients. REFERENCES 1. Alpers BJ, Berry RG, Pddison RM: Antomicl studies of the circle of Willis in norml rin. Arch Neurol Psychitry 81: , Aydin IH, Tkci E, Kdioglu HH, Tuzun Y, Kyoglu CR, Brls E: Vsculr vritions ssocited with nterior communicting rtery neurysms-n intropertive study. Minim Invsive Neurosurg 40(1):17-21, Biondi A: Intrcrnil neurysms ssocited with other lesions, disorders or ntomic vritions. Neuroimg Clin N Am 16: , Dimmick SJ, Fulder KC: Fenestrted nterior cererl rtery with ssocited rteril nomlies. Cse reports nd literture review. Interv Neurordiol 14: , Gio H, Crver CC, Rhoton AL Jr, Lenkey C, Mitchell RJ: Microsurgicl ntomy of the middle cererl rtery. J Neurosurg 54(2): , Gunnl SA, Frooqui MS, Wle RN: Antomicl vritions of the Circulus Arteriosus in cdveric humn rins. Neurol Res Int 2014:687281, Gunnl S, Frooquı M, Wle R: Antomicl vriility in the termintion of the silr rtery in the humn cdveric rin. Turk Neurosurg 25(4): , Iql S: A comprehensive study of the ntomicl vritions of the Circle of Willis in dult humn rins. J Clin Dign Res 7(11): , Kmth S: Oservtions on the length nd dimeter of the vessels forming the circle of Willis. J Ant 133: , Kpoor K, Singh B, Dewn LI: Vritions in the configurtion of the circle of Willis. Ant Sci Int 83:96-106, Krts A, Yilmz H, Con G, Koker M, Uz A: The Antomy of Circulus Arteriosus Cereri (Circle of Willis): A study in Turkish popultion. Turk Neurosurg 26(1):54-61, Kyeme KN, Sshr M, Hzm F: Cererl neurysms nd vritions in the circle of Willis. Stroke 15: , Kovč JD, Stnković A, Stnković D, Kovč B, Šrnović D: Intrcrnil rteril vritions: A comprehensive evlution using CT ngiogrphy. Med Sci Monit 20: , Krsny A, Nens F, Sndlcioglu IE, Göricke SL, Wnke I, Grmsch C, Sirin S, Oezkn N, Sure U, Schlmnn M: Assocition of neurysms nd vrition of the A1 segment. J Neurointerv Surg 6 (3): , Kryenuhl H, Ysrgil M: Cererl ngiogrphy. London: Butterworths, 1968: Krzyżewski RM, Tomszewsk IM, Lorenc N, Kochn M, Goncerz G, Piotrowsk WK, Wloch K, Urnik A: Vritions of the nterior communicting rtery complex nd occurence of nterior communicting rtery neurysm: A2 segment. Considertion Foli Medic Crcoviensi 54:13-20, Krzyżewski RM, Tomszewski KA, Kochn M, Kopeć M, Klimek-Piotrowsk W, Wloch JA: A rre ntomicl vrint: Medin nterior cererl rtery fenestrtion ssocited with n zygous infr-optic nterior cererl rtery. Surg Rdiol Ant 37(1):81-86, 2015 Turk Neurosurg 27(6): ,

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