distal anterior cerebral artery aneurysms , also known as pericallosal artery ( pa ) aneurysms , are located on the anterior cerebral artery distal to the anterior communicating artery .
these aneurysms represent approximately 6% of all intracranial aneurysms and 4% of those that rupture49 ) .
furthermore , they were similarly represented in the international subarachnoid aneurysm trial ( isat ) study population , in which they accounted for 95 of the 2143 patients randomized ( 4.4%)14 ) .
pa aneurysms present several problems for direct surgical clipping , that is , difficult exposure via an interhemispheric approach , especially in a swollen brain after subarachnoid hemorrhage ( sah ) , sacrifice of a bridging vein for adequate surgical exposure ( thus increasing the risk of postoperative morbidity ) , difficult controlling the parent artery , and the unfavorable orientation of the aneurysm fundus . as a consequence ,
surgical morbidity has been reported to be relatively high , with incidences ranging from 0 to 25%141221 ) .
advances in endovascular techniques and devices have led to the rapid evolution of coil embolization of ruptured and unruptured intracranial aneurysms , and it has now become an efficient treatment technique that is comparable to surgical clipping . however , because of their distal location and the small diameter of the parent vessel , pa aneurysms pose a technical challenge for endovascular therapy and , as is the case for most bifurcation cerebral aneurysms , have a potential high recurrence rate18 ) . a search of the literature revealed relatively few studies have been performed on the endovascular treatment of ruptured pa aneurysms , and that the studies performed involved relatively small numbers of patient . accordingly , it is evident that the effectiveness and safety of the endovascular treatment of ruptured pa aneurysms have not been well - defined . here
, we present 30 patients that were treated endovascularly for a ruptured pa aneurysm and describe their clinical and radiologic outcomes .
we retrospectively analyzed the angiographic and clinical records of all patients that underwent endovascular treatment for a ruptured pa aneurysm at our institution from september 2003 to december 2013 .
the treatment strategy for ruptured pa aneurysm at our institution was to attempt endovascular treatment as the first - line treatment .
this strategy was applied to those accompanied by intraparenchymal hematoma ( ich ) , and surgical evacuation , if necessary , was performed in the immediately following coiling .
however , microsurgery was used in the early years of this study because the technology for coiling of distally located aneurysms was in its infancy . therefore , surgical clipping was first attempt in 6 cases during the same period .
there was no technical failure in both clipping and coiling groups . due to the retrospective nature ,
the present study is exempt in accord with the institutional review board standards of our institution .
thirty ruptured pa aneurysms in 30 patients were treated endovascularly , and there were 10 males and 20 females of mean age 55.9 years ( range , 24 to 88 years ) . dissecting or fusiform aneurysms , aneurysms associated with a brain arteriovenous malformation , and traumatic or mycotic aneurysms were excluded .
size of aneurysms and parent arteries were measured automatically and manually on two - dimen sional digital subtraction angiography working views .
aneurysm size was defined as the maximum distance of the dome from the neck plane .
aneurysm and neck sizes ranged from 2.5 to 10.4 mm ( mean 5.0 mm ) and from 0.9 to 6.1 mm ( mean 2.2 mm ) , respectively .
21 of the 30 saccular aneurysms were defined as wide - neck aneurysms ( a large neck size of 4 mm and/or a dome - to - neck ratio of 2 ) .
of the 30 pa aneurysms , 23 ( 76.7% ) were located at the pericallosal - callosomarginal junction and 7 ( 23.3% ) at the pericallosal - frontopolar junction .
fifteen pa aneurysms were on the left side , 13 on the right , and 2 at midline ( azygos artery ) .
all patients were clinically assessed at admission using hunt and hess grades ; 12 patients ( 40.0% ) grade ii , 9 ( 30.0% ) grade iii , 6 ( 20.0% ) grade v , and 3 ( 10.0% ) grade iv .
fifteen patients ( 50.0% ) had a concomitant ich that was managed conservatively in all but two cases that required surgical evacuation .
in general , endovascular treatment was performed as soon as possible after sah , regardless of clinical condition .
coiling of aneurysms was performed under local anesthesia , and intravenous bolus injection of standard heparin was not performed during the procedure .
however , drip infusion of heparin was carried out employing catheter pressure infusion systems with continuous infusion of 1000 u of heparin per 1000 ml of saline .
the aim of the coiling was to obtain a packing of the aneurysm as attenuated as possible .
the remodeling techniques using a balloon or stent or multiple catheters were unavailable for the aneurysms treated during the early part of our series .
however , we have recently favored these remodeling techniques to achieve higher postoperative occlusion rates . when an aneurysm could not be reached using standard procedures because of a distal location and instability of the microcatheter , the guiding catheter was placed more distal into the internal carotid artery .
care was taken not to interfere with the flow of the carotid or parent artery . by using these means
, all aneurysms were reached with a microcatheter . in the case of intraprocedural thromboembolic complication
, various strategies for thrombolysis were applied , such as mechanical thrombolysis and intra - arterial or intravenous abciximab , or heparin infusion during or after the procedure . immediately after the procedure
furthermore , all patients underwent a non - enhanced brain computed tomography ( ct ) scan to evaluate possible hemorrhagic complications .
unless the thromboembolic complication occurred or a stent was used , further antiplatelet or anticoagulant medications were not administered .
the indications for long - term antiplatelet therapy of acetylsalicylic acid and/or clopidogrel were ; the formation of a thrombus at the end of the coil or thromboembolic events , stent - assisted coiling , and coil protrusion into the parent artery .
occlusion was classified as ; complete when no contrast filling of the aneurysmal sac and neck was observed , near - complete when contrast filling of the neck of the aneurysm was slow or partial when any degree of contrast filling was observed within the aneurysm sac .
clinical results were assessed upon discharge from hospital or at last visit using the modified rankin scale ( mrs ) , as follows : 0 , no symptoms at all ; 1 , no significant disability ; 2 , slight disability ; 3 , moderate disability ; 4 , moderately severe disability ; 5 , severe disability ; and 6 , death .
complications were defined as all adverse events related to the procedure , and these were studied retrospectively using medical and operative reports .
early rebleeding was defined as expanding hemorrhage with worsening of the patient 's condition within 30 days after coiling , and diagnostic confirmation was made by ct when it showed an increased amount of hemorrhage compared with immediate postprocedural ct .
univariate and multivariate logistic regression analyses were used to identify risk factors associated with periprocedural rebleeding or a poor clinical outcome .
results are presented as odds ratios ( ors ) and 95% confidence intervals ( cis ) .
variables showing a univariate association with a dependent risk factor ( p<0.10 ) were included in the multivariate logistic analysis .
chicago , il , usa ) . statistical significance was accepted for p values of < 0.05 .
we retrospectively analyzed the angiographic and clinical records of all patients that underwent endovascular treatment for a ruptured pa aneurysm at our institution from september 2003 to december 2013 .
the treatment strategy for ruptured pa aneurysm at our institution was to attempt endovascular treatment as the first - line treatment .
this strategy was applied to those accompanied by intraparenchymal hematoma ( ich ) , and surgical evacuation , if necessary , was performed in the immediately following coiling .
however , microsurgery was used in the early years of this study because the technology for coiling of distally located aneurysms was in its infancy . therefore , surgical clipping was first attempt in 6 cases during the same period .
there was no technical failure in both clipping and coiling groups . due to the retrospective nature ,
the present study is exempt in accord with the institutional review board standards of our institution .
thirty ruptured pa aneurysms in 30 patients were treated endovascularly , and there were 10 males and 20 females of mean age 55.9 years ( range , 24 to 88 years ) . dissecting or fusiform aneurysms , aneurysms associated with a brain arteriovenous malformation , and traumatic or mycotic aneurysms were excluded .
size of aneurysms and parent arteries were measured automatically and manually on two - dimen sional digital subtraction angiography working views .
aneurysm size was defined as the maximum distance of the dome from the neck plane .
aneurysm and neck sizes ranged from 2.5 to 10.4 mm ( mean 5.0 mm ) and from 0.9 to 6.1 mm ( mean 2.2 mm ) , respectively .
21 of the 30 saccular aneurysms were defined as wide - neck aneurysms ( a large neck size of 4 mm and/or a dome - to - neck ratio of 2 ) .
of the 30 pa aneurysms , 23 ( 76.7% ) were located at the pericallosal - callosomarginal junction and 7 ( 23.3% ) at the pericallosal - frontopolar junction .
fifteen pa aneurysms were on the left side , 13 on the right , and 2 at midline ( azygos artery ) .
all patients were clinically assessed at admission using hunt and hess grades ; 12 patients ( 40.0% ) grade ii , 9 ( 30.0% ) grade iii , 6 ( 20.0% ) grade v , and 3 ( 10.0% ) grade iv .
fifteen patients ( 50.0% ) had a concomitant ich that was managed conservatively in all but two cases that required surgical evacuation .
in general , endovascular treatment was performed as soon as possible after sah , regardless of clinical condition .
coiling of aneurysms was performed under local anesthesia , and intravenous bolus injection of standard heparin was not performed during the procedure .
however , drip infusion of heparin was carried out employing catheter pressure infusion systems with continuous infusion of 1000 u of heparin per 1000 ml of saline .
the aim of the coiling was to obtain a packing of the aneurysm as attenuated as possible .
the remodeling techniques using a balloon or stent or multiple catheters were unavailable for the aneurysms treated during the early part of our series .
however , we have recently favored these remodeling techniques to achieve higher postoperative occlusion rates . when an aneurysm could not be reached using standard procedures because of a distal location and instability of the microcatheter , the guiding catheter was placed more distal into the internal carotid artery .
care was taken not to interfere with the flow of the carotid or parent artery . by using these means ,
all aneurysms were reached with a microcatheter . in the case of intraprocedural thromboembolic complication , various strategies for thrombolysis were applied , such as mechanical thrombolysis and intra - arterial or intravenous abciximab , or heparin infusion during or after the procedure . immediately after the procedure
furthermore , all patients underwent a non - enhanced brain computed tomography ( ct ) scan to evaluate possible hemorrhagic complications .
unless the thromboembolic complication occurred or a stent was used , further antiplatelet or anticoagulant medications were not administered .
the indications for long - term antiplatelet therapy of acetylsalicylic acid and/or clopidogrel were ; the formation of a thrombus at the end of the coil or thromboembolic events , stent - assisted coiling , and coil protrusion into the parent artery .
occlusion was classified as ; complete when no contrast filling of the aneurysmal sac and neck was observed , near - complete when contrast filling of the neck of the aneurysm was slow or partial when any degree of contrast filling was observed within the aneurysm sac .
clinical results were assessed upon discharge from hospital or at last visit using the modified rankin scale ( mrs ) , as follows : 0 , no symptoms at all ; 1 , no significant disability ; 2 , slight disability ; 3 , moderate disability ; 4 , moderately severe disability ; 5 , severe disability ; and 6 , death .
complications were defined as all adverse events related to the procedure , and these were studied retrospectively using medical and operative reports .
early rebleeding was defined as expanding hemorrhage with worsening of the patient 's condition within 30 days after coiling , and diagnostic confirmation was made by ct when it showed an increased amount of hemorrhage compared with immediate postprocedural ct .
univariate and multivariate logistic regression analyses were used to identify risk factors associated with periprocedural rebleeding or a poor clinical outcome .
results are presented as odds ratios ( ors ) and 95% confidence intervals ( cis ) .
variables showing a univariate association with a dependent risk factor ( p<0.10 ) were included in the multivariate logistic analysis .
chicago , il , usa ) . statistical significance was accepted for p values of < 0.05 .
the microcatheter was navigated into the lumen of the pa aneurysm and coils were delivered in all 30 patient .
the treatment of 19 aneurysms was straightforward , but the other 11 required an adjunctive technique , that is , double catheter , balloon - assisted , or a stent - assisted technique .
immediate post - procedural angiograms showed complete aneurysm occlusion in 21 ( 21/30 , 70.0% ) and near - complete occlusion in 9 ( 9/30 , 30.0% ) .
procedure - related thromboembolic complications developed in two patients ( 2/30 , 6.7% ) . in one patient , occlusion of a callosomarginal artery occurred due to thrombus formation at the artery origin , which resulted in right leg monoparesis .
the other thromboembolism occurred in the inferior m2 segment of the middle cerebral artery during the procedure , a relevant infarction was observed 2 days after coiling .
diagnosis of intraprocedural rupture was made based on the angiographic visualization of contrast material extravasation in two cases .
the coil was observed partially outside the aneurysm with a sudden rise in arterial blood pressure but without angiographic demonstration of extravasation of contrast medium in one case .
the mean delay between coiling and early rebleeding was 31 hours ( range , 2 - 83 hours ) .
in these three patients , intravenous bolus of 3000 iu of heparin was injected during the procedure only in one case needed a stent .
besides drip infusion of heparin during the procedure , further antiplatelet or anticoagulant medications were not administered in the other two cases .
of these six patients with periprocedural rebleeding , five had small ( 4 mm ) aneurysms , but one had large ( 9.9 mm ) and multi - lobulated aneurysm .
furthermore , the five patients ( 5/6 , 83.3% ) concerned had an adjacent hematoma on initial ct scans , and three ( 3/6 , 50.0% ) showed contrast retention and delayed washout by the aneurysm by preprocedural digital subtraction angiography .
in these six patients with periprocedural rebleeding , no new neurologic deficit developed in three patients ( 3/6 , 50.0% ) , but deterioration of consciousness , resulting in death , occurred in two patients ( 2/6 , 33.3% ) .
it could be questioned as to whether the early rebleeding had worsened clinical status in one patient , because the patient had initial severe sah and died within 5 days after sah onset .
thus , the periprocedural mortality in our cohort was 6.7% ( 2/30 ) and morbidity was 3.3% ( 1/30 ) .
table 3 provides a summary of the risk factors found to be associated with periprocedural rebleeding .
the associations of all variables with periprocedural rebleeding were examined by univariate logistic regression analysis , and contrast retention was found to be associated with an increased risk of periprocedural rebleeding ( or : 23.000 ; 95% ci : 1.773 to 298.446 ; p=0.016 ) .
furthermore , multivariate logistic - regression analysis adjusted for adjacent hematoma confirmed the validity of this relationship ( or : 21.352 ; 95% ci : 1.310 to 347.917 ; p=0.032 ) . only one patient ( 1/30 , 3.3% ) suffered from symptomatic vasospasm and , fortunately , no negative long - term effects were observed .
clinical results were assessed upon discharge from hospital or at last follow - up visit using the mrs . at the end of the observational period ,
18 patients were independent with a mrs score of 0 - 2 ( 18/30 , 60.0% ) , and the other 12 ( 12/30 , 40% ) were dependent ( mrs score , 3 - 6 ) .
seven of the 12 had a mrs score of 6 ( due to a poor preoperative status in five and procedure - related rebleeding in two ) , three had a mrs score of 5 ( due to poor preoperative status or old age ) , one had a mrs score of 4 ( due to old age ) , and one had a mrs score of 3 ( due to a large ich ) .
the 23 surviving patients were followed for 6 - 68 months ( mean , 32.7 months ) .
no neurologic deterioration or hemorrhagic complication occurred during follow - up period in any of these patients .
univariate logistic - regression analysis showed that age ( or : 1.080 ; 95% ci : 1.003 to 1.163 ; p=0.043 ) , adjacent hematoma ( or : 13.000 ; 95% ci : 2.074 to 81.479 ; p=0.006 ) , and hunt and hess grade 3 - 5 ( or : 13.750 ; 95% ci : 1.452 to 130.239 ; p=0.022 ) were associated with a poor clinical outcome .
however , multivariate logistic - regression analysis adjusted for age and hunt and hess grade 3 - 5 showed that only adjacent hematoma was associated with a poor clinical outcome ( or : 47.734 ; 95% ci : 1.596 to 1427.240 ; p=0.026 ) .
seventeen of the 23 surviving patients underwent follow - up conventional angiography between 1 and 65 months postoperatively ( mean , 16.5 months ) . according to the follow - up images obtained , 9 of the 10
initially occluded aneurysms remained completely occluded and the remaining one showed partial recanalization due to coil compaction .
repeat follow - up angiography at 20 months showed in this patient that the condition was stable , and the patient concerned declined additional therapy .
five of the 7 aneurysms initially showing near complete occlusion remained stable at follow - up .
recoiling was undertaken in the patient showing major recanalization at 13 months postoperatively , and complete occlusion was achieved .
thus , the overall stable occlusion rate was 82.4% ( 14/17 ) and the recanalization rate was 17.6% ( 3/17 ) .
parent arteries of the aneurysm treated by y - stent - assisted coiling remained patent with no evidence of intimal hyperplasia or in - stent stenosis .
the microcatheter was navigated into the lumen of the pa aneurysm and coils were delivered in all 30 patient .
the treatment of 19 aneurysms was straightforward , but the other 11 required an adjunctive technique , that is , double catheter , balloon - assisted , or a stent - assisted technique .
immediate post - procedural angiograms showed complete aneurysm occlusion in 21 ( 21/30 , 70.0% ) and near - complete occlusion in 9 ( 9/30 , 30.0% ) .
procedure - related thromboembolic complications developed in two patients ( 2/30 , 6.7% ) . in one patient , occlusion of a callosomarginal artery occurred due to thrombus formation at the artery origin , which resulted in right leg monoparesis .
the other thromboembolism occurred in the inferior m2 segment of the middle cerebral artery during the procedure , a relevant infarction was observed 2 days after coiling . however , the patient concerned did not experience any neurological symptom .
diagnosis of intraprocedural rupture was made based on the angiographic visualization of contrast material extravasation in two cases .
the coil was observed partially outside the aneurysm with a sudden rise in arterial blood pressure but without angiographic demonstration of extravasation of contrast medium in one case .
the mean delay between coiling and early rebleeding was 31 hours ( range , 2 - 83 hours ) .
in these three patients , intravenous bolus of 3000 iu of heparin was injected during the procedure only in one case needed a stent .
besides drip infusion of heparin during the procedure , further antiplatelet or anticoagulant medications were not administered in the other two cases .
of these six patients with periprocedural rebleeding , five had small ( 4 mm ) aneurysms , but one had large ( 9.9 mm ) and multi - lobulated aneurysm .
furthermore , the five patients ( 5/6 , 83.3% ) concerned had an adjacent hematoma on initial ct scans , and three ( 3/6 , 50.0% ) showed contrast retention and delayed washout by the aneurysm by preprocedural digital subtraction angiography .
in these six patients with periprocedural rebleeding , no new neurologic deficit developed in three patients ( 3/6 , 50.0% ) , but deterioration of consciousness , resulting in death , occurred in two patients ( 2/6 , 33.3% ) .
it could be questioned as to whether the early rebleeding had worsened clinical status in one patient , because the patient had initial severe sah and died within 5 days after sah onset .
thus , the periprocedural mortality in our cohort was 6.7% ( 2/30 ) and morbidity was 3.3% ( 1/30 ) .
table 3 provides a summary of the risk factors found to be associated with periprocedural rebleeding .
the associations of all variables with periprocedural rebleeding were examined by univariate logistic regression analysis , and contrast retention was found to be associated with an increased risk of periprocedural rebleeding ( or : 23.000 ; 95% ci : 1.773 to 298.446 ; p=0.016 ) .
furthermore , multivariate logistic - regression analysis adjusted for adjacent hematoma confirmed the validity of this relationship ( or : 21.352 ; 95% ci : 1.310 to 347.917 ; p=0.032 ) .
only one patient ( 1/30 , 3.3% ) suffered from symptomatic vasospasm and , fortunately , no negative long - term effects were observed .
clinical results were assessed upon discharge from hospital or at last follow - up visit using the mrs . at the end of the observational period ,
18 patients were independent with a mrs score of 0 - 2 ( 18/30 , 60.0% ) , and the other 12 ( 12/30 , 40% ) were dependent ( mrs score , 3 - 6 ) .
seven of the 12 had a mrs score of 6 ( due to a poor preoperative status in five and procedure - related rebleeding in two ) , three had a mrs score of 5 ( due to poor preoperative status or old age ) , one had a mrs score of 4 ( due to old age ) , and one had a mrs score of 3 ( due to a large ich ) .
the 23 surviving patients were followed for 6 - 68 months ( mean , 32.7 months ) .
no neurologic deterioration or hemorrhagic complication occurred during follow - up period in any of these patients .
univariate logistic - regression analysis showed that age ( or : 1.080 ; 95% ci : 1.003 to 1.163 ; p=0.043 ) , adjacent hematoma ( or : 13.000 ; 95% ci : 2.074 to 81.479 ; p=0.006 ) , and hunt and hess grade 3 - 5 ( or : 13.750 ; 95% ci : 1.452 to 130.239 ; p=0.022 ) were associated with a poor clinical outcome .
however , multivariate logistic - regression analysis adjusted for age and hunt and hess grade 3 - 5 showed that only adjacent hematoma was associated with a poor clinical outcome ( or : 47.734 ; 95% ci : 1.596 to 1427.240 ; p=0.026 ) .
seventeen of the 23 surviving patients underwent follow - up conventional angiography between 1 and 65 months postoperatively ( mean , 16.5 months ) . according to the follow - up images obtained , 9 of the 10
initially occluded aneurysms remained completely occluded and the remaining one showed partial recanalization due to coil compaction .
repeat follow - up angiography at 20 months showed in this patient that the condition was stable , and the patient concerned declined additional therapy .
five of the 7 aneurysms initially showing near complete occlusion remained stable at follow - up .
recoiling was undertaken in the patient showing major recanalization at 13 months postoperatively , and complete occlusion was achieved .
thus , the overall stable occlusion rate was 82.4% ( 14/17 ) and the recanalization rate was 17.6% ( 3/17 ) .
parent arteries of the aneurysm treated by y - stent - assisted coiling remained patent with no evidence of intimal hyperplasia or in - stent stenosis .
ruptured pa aneurysms may be technically difficult to clip because of the narrow exposure afforded by an interhemispheric approach , difficulty control of the parent artery , and sacrifice of a bridging vein to achieve adequate surgical exposure .
surgical morbidity has been reported to be relatively high , with incidences ranging from 0 to 25%141221 ) .
endovascular treatment of ruptured pa aneurysms has been reported to be technically difficult , primarily because of the long access route , which complicates microcatheter manipulation , and the small aneurysmal lumen .
the introduction of new microcatheter and microguidewire with improved trackability , pushability , and torque and novel hydrophilic coatings have facilitated navigation into distant cerebral arteries , such as , the pa . furthermore , the availabilities of various soft coils may have contributed to the higher success rate of small aneurysm coiling without intraoperative rupture .
we found that the pa could be reached and coiling of the aneurysm accomplished in all 30 patients .
in fact , even a 2.5 mm sized aneurysm located at a distal junction was occluded successfully . in our series ,
an independent daily living activity level ( mrs score , 0 - 2 ) was achieved by 60% of our patients ( 18/30 ) .
the poor clinical outcomes ( mrs score , 3 - 6 ) of the other 12 patients resulted from poor preoperative status , periprocedural rebleeding , old age , and large ich .
waldenberger et al.25 ) reported that the most important negative contributor to the outcome of pa aneurysm coiling was the presence of ich , and this was followed by thromboembolic complications and poor preoperative status .
ruptured pa aneurysms cause ich , in addition to sah , in more than one - half of cases , and are associated with poorer outcomes after rupture than aneurysms in other locations311 ) .
in the present study , 15 of the 30 patients ( 50.0% ) had a concomitant ich that was visualized on initial ct scans , and 10 of the patients ( 10/15 , 66.7% ) had a poor clinical outcome ( mrs score , 3 - 6 ) .
furthermore , multivariate logistic - regression analysis showed that adjacent hematoma was the only independent predictor of a poor clinical outcome ( or : 47.734 ; 95% ci : 1.596 to 1427.240 ; p=0.026 ) .
other variables , such as , age and hunt and hess grade were of borderline significance , possibly due to the small number of patients enrolled ( table 4 ) .
we have summarized the reported studies in which more than 10 patients with ruptured pericallosal artery aneurysms were treated with endovascular treatment in table 5 . in a recently reported meta - analysis of endovascular treatment of pa aneurysms including 16 studies , the authors concluded that endovascular treatment of pa aneurysms is associated with high angiographic occlusion rates , but the complication rates are higher compared with other aneurysms in the circle of willis .
procedure - related ischemia and iatrogenic rupture occurred in 5% and 7% of patients , respectively .
procedure - related permanent morbidity rate was 8%23 ) . in the present study , the overall procedure - related complication rate was 26.7% ( 8/30 cases ) .
two patients experienced thromboembolic events and acute infarctions and developed corresponding neurologic deficits , though fortunately showed no neurological deficit at follow - up .
intraprocedural rupture occurred from three aneurysms ( 10.0% ) , which was markedly greater than anticipated .
a review of the literature revealed pa aneurysms have a higher procedure - related rupture rate than non - pa aneurysms .
keston et al.9 ) reported an intraprocedural rupture rate of 18% ( 3/17 patients ) for pa aneurysms , which compared with an overall departmental five year ( 1999 - 2003 inclusive ) intraprocedural rupture rate of only 1.1% ( 7/640 patients ) for non - pa aneurysms .
nguyen et al.15 ) reported a 12% ( 3/25 patients ) procedure - related perforation rate in their endovascular series of pa aneurysms .
based on these reports and the fact that previous reports included unruptured cases , whereas we did not , we believe that our intraprocedural rupture rate is not excessive .
it is well known pa aneurysms are smaller than non - pa aneurysms tend and that they tend to rupture at a smaller size101327 ) . in a study of a large number of aneurysm cases , the average diameter of ruptured aneurysms was reported to be 8.2 mm8 ) , whereas the average aneurysm diameter in our patients was 5.0 mm .
we believe this difference could explain the higher intraprocedural rupture rate in the endovascular treatment of ruptured pa aneurysms .
in addition , to aneurysm size , the risk of procedure - induced perforation may also be related to anatomical peculiarities .
a more distal location leads to catheter positioning via a longer segment in a small - caliber vessel , which reduces the degree of catheter deflection when a coil encounters resistance15 ) .
prior studies on early rebleeding after coiling have reported rupture rates of 1.4% to 2.6%6722 ) .
incomplete embolization , adjacent hematoma , small aneurysms , and post - procedural anticoagulation have been reported to be associated with early rebleeding after coiling .
the cerebral aneurysm rerupture after treatment study reported that the risk of posttreatment rebleeding was closely associated with the degree of aneurysm occlusion7 ) .
however , we experienced three cases with early rebleeding after coiling ( 10.0% ) , despite all three aneurysms being complete embolized during the procedure .
the presence of adjacent hematoma is a strong , independent risk factor of early rebleeding and a thrombosed pseudoaneurysm and hematoma could cause early reopening and rehemorrhage22 ) . in our series , all three cases with early rebleeding accompanied by adjacent hematoma . at coiling ,
a pseudoaneurysm may or may not be visible by angiography . if a pseudoaneurysm is apparent by angiography , coiling of the true aneurysm and the pseudoaneurysm can be considered , but the fragile wall of the pseudoaneurysm is prone to perforation , and this has been prompted to advise against catheterization into false lumen16 ) . on the other hand , cho et al.2 ) , who reported on early recurrent hemorrhage after coil embolization in ruptured intracranial aneurysms , hypothesized another possibility that rebleeding with ich may be caused by delayed hemorrhage or propagation of the initial ich due to vulnerability of the parenchyma adjacent to the ich , rather than by rebleeding of the coiled aneurysm .
early rebleeding after coiling of a ruptured aneurysm and intra - procedural rupture are major concerns , because associated mortality rates are high .
when a ruptured pa aneurysm accompanied by adjacent hematoma , decisions regarding endovascular treatment should be taken only after carefully considering the possibility of periprocedural rebleeding .
therefore , it may be better to consider the surgical clipping of a ruptured pa aneurysm with adjacent hematoma as a first option to prevent periprocedural rebleeding . with regard to treatment durability , recurrence requiring recoiling due to the risk of re - rupture , developed in one of our 17 cases , who developed major recanalization . in the present study ,
the overall recanalization rate was 17.6% ( 3/17 ) but the major recanalization rate was only 5.9% ( 1/17 ) .
recurrence after coiling has been reported to be associated primarily with aneurysm size7162226 ) . in one study ,
follow - up angiographic studies after complete occlusion showed recurrence rates of 14% for aneurysms of < 5 mm , 27% for aneurysms of 5 - 10 mm , and 57% for aneurysms of 10 mm23 ) .
therefore , the lower rate of recurrence in our series could have been due to the lower proportion of cases with aneurysms 5 mm ( 9/30 , 30.0% ) .
however , in a recent series of 16 cases of pa aneurysm coiling , there was a comparatively high recurrence rate ( one major and five minor recurrences , 37.5% ) , attributed to the loose coil packing rate19 ) .
this study is limited by its retrospective design , patient - selection bias , small cohort , relatively short angiographic follow - up , by the fact that it was conducted at a single institution .
nonetheless , our findings suggest that the endovascular treatment of ruptured pa aneurysms appears to be a valid treatment strategy given suitable levels of institutional and operator expertise .
our experiences show that the endovascular treatment of ruptured pa aneurysms is both feasible and effective .
however , they show periprocedural rebleeding occur far more frequently ( 20.0% ) than is generally considered and that these rebleeding are associated with preprocedural contrast retention . accordingly
, our findings caution that decisions regarding endovascular treatment in cases showing preprocedural contrast retention should approached by carefully considering the possibility of periprocedural rebleeding .
furthermore , an existing adjacent hematoma was found to have a severe negative influence on clinical outcome .
 objectiveaneurysms arising from the pericallosal artery ( pa ) are uncommon and challenging to treat . 
 the aim of this study was to report our experiences of the endovascular treatment of ruptured pa aneurysms.methodsfrom september 2003 to december 2013 , 30 ruptured pa aneurysms in 30 patients were treated at our institution via an endovascular approach . 
 procedural data , clinical and angiographic results were retrospectively reviewed.resultsregarding immediate angiographic control , complete occlusion was achieved in 21 ( 70.0% ) patients and near - complete occlusion in 9 ( 30.0% ) . 
 eight procedure - related complications occurred , including intraprocedural rupture and early rebleeding in three each , and thromboembolic event in two . at last follow - up 
 , 18 patients were independent with a modified rankin scale ( mrs ) score of 0 - 2 , and the other 12 were either dependent or had expired ( mrs score , 3 - 6 ) . 
 adjacent hematoma was found to be associated with an increased risk of poor clinical outcome . 
 seventeen of 23 surviving patients underwent follow - up conventional angiography ( mean , 16.5 months ) . 
 results showed stable occlusion in 14 ( 82.4% ) , minor recanalization in two ( 11.8% ) , and major recanalization , which required recoiling , in one ( 5.9%).conclusionour experiences demonstrate that endovascular treatment for a ruptured pa aneurysms is both feasible and effective . 
 however , periprocedural rebleedings were found to occur far more often ( 20.0% ) than is generally suspected and to be associated with preoperative contrast retention . 
 analysis showed existing adjacent hematoma is predictive of a poor clinical outcome . 
INTRODUCTION
MATERIALS AND METHODS
Patient population and aneurysm morphologies
Endovascular procedure
Clinical and angiographic follow-up
Statistical analysis
RESULTS
Immediate angiographic results and complications
Clinical status at discharge or during follow-up
Follow-up angiographic results
DISCUSSION
CONCLUSION