Influence of Intraoperative Ventriculostomy on the Occurrence of Shunt - Dependent Hydrocephalus in Aneurysmal Subarachnoid Hemorrhage Tae Koo Cho, MD 1 Jae Min Kim, MD, PhD 1 Sung Soo Kim, MD 1 Hyeong Joong Yi, MD, PhD 2, Jin Hwan Cheong, MD, PhD 1 Koang Hum Bak, MD, PhD 1 Choong Hyun Kim, MD, PhD 1 1 Department of Neurosurgery, Hanyang University Guri Hospital, Guri, Korea 2 Department of Neurosurgery, Hanyang University Medical Center, Seoul, Korea Objective : Neurosurgeons occasionally advocated intraoperative ventriculostomy to prevent traumatic brain retraction because of severe brain swelling in an acute stage of aneurysmal subarachnoid hemorrhage (SAH) surgery. The authors investigated the impact of the intraoperative ventriculostomy on the occurrence of shunt-dependent hydrocephalus in acute SAH. Methods : The data of 141 ruptured aneurysm patients who underwent aneurysmal neck clipping in an acute stage were retrospectively reviewed. The patients were divided into three groups according to the cerebrospinal fluid (CSF) drainage amount via intraoperative ventriculostomy. Group 1 (n=44) included the patients who were not performed the intraoperative ventriculostomy, Group 2 (n=34) consisted of patients who were drained the CSF less than 40 cc (<40 cc) via intraoperative ventriculostomy, and Group 3 (n=63) drained the CSF more than 40 cc ( 40 cc). By using statistical methods, the authors analyzed the influences of various variables including Hunt-Hess grade, Fisher grade, Glasgow coma scale, Glasgow outcome scale, presence of acute hydrocephalus and intraventricular hemorrhage (IVH) at admission on the occurrence of hydrocephalus. And also, we analyzed the relationships among the cisternal drainage, lamina terminalis fenestration, and the shunt-dependent hydrocephalus. Results : Concerning the amount of CSF drainage via intraoperative ventriculostomy, the incidence of shunt-dependent hydrocephalus did not show any difference in three groups (p=0.146). Presence of the acute hydrocephalus, lamina terminalis fenestration, and cisternal drainage did not exert any influence on the incidence of shunt-dependent hydrocephalus, respectively (p=0.124, p=0.168, p=0.452). However, the incidence of shunt-dependent hydrocephalus in patients who had IVH at admission was significantly higher than in who did not have (p=0.010). Conclusions : Routine intraoperative ventriculostomy dose not increase the incidence of shunt-dependent hydrocephalus. Moreover, it obtains an adequate intraoperative brain relaxation, which results in the decrease of the brain retraction injury and the operation time. (Kor J Cerebrovascular Surgery 8:48-55, 2006) KEY WORDS : Ventriculostomy Hydrocephalus Shunt Aneurysm Subarachnoid hemorrhage 논문접수일 : 2006 년 6 월 12 일심사완료일 : 2006 년 6 월 22 일교신저자 : 김재민, 471-701 경기도구리시교문동 249-1 한양대학교구리병원신경외과학교실전화 : (031) 560-2323 전송 : (031) 560-2327 E-mail : kjm2323@hanyang.ac.kr 서론 수두증은뇌동맥류의재출혈, 뇌혈관연축 (cerebral vasospasm) 과더불어동맥류파열에의한뇌지주막하출혈후나타날수있는중요한합병증으로, 10)33) 빈도는 6~67% 까지다양하게보고되고있으며, 2)24)30)33)35) 발생시기도수일에서
수년까지다양한것으로나타나있다. 19)25)34)35) 수두증은발생시기에따라급성 ( 출혈직후 ~3일 ), 아급성 ( 출혈후4일 ~13일 ) 과만성 ( 출혈후14일이상 ) 으로분류된다. 32) 급성수두증의경우실비우스수도 (aqueduct of Sylvius), 3) 제 4뇌실의출구, 뇌기저조 (basal cistern), 뇌지주막하강에서뇌척수액의흐름이방해받거나, 2)7)15) 혈구가지주막융모에유착하여뇌척수액의흡수를막아생긴다고알려져있으며, 8) 만성수두증의경우혈액에대한연수막반응 (leptomeningeal reaction) 으로연막-지주막의유착에의하여발생한다고알려져있다. 35) 출혈후 14일이상수두증이지속되거나후에발생한만성수두증의경우는대부분단락술이필요하며, 32) 단락술을요하는수두증은뇌지주막하출혈환자의 20% 에서발생된다고한다. 1)9)11)20) 뇌지주막하출혈수술후만성수두증의발생에영향을미칠수있는요소들로는성별, 나이, 내원당시의식상태, 뇌지주막하출혈의양, 뇌실내출혈의유무, 파열된동맥류의위치, 급성수두증의유무, 고혈압또는당뇨병의유무등이보고되어있으나, 2)6)10)20)27-29)32)35) 아직까지명확한결론을내리지못하고있어발생에관여하는위험인자에대해서는많은논란이있다. 테리온접근법 (pterional approach) 에의한뇌동맥류수술시에두개내압을감소시키고, 뇌견인에의한뇌손상을최소화하기위해수술중뇌실천자술 (ventriculostomy) 이사용되고있다. 본연구는뇌동맥류파열에의한뇌지주막하출혈환자를대상으로수두증을일으키는데관여하는여러요인들중에서수술중뇌실천자술이단락술을요하는수두증 (shunt-dependent hydrocephalus) 의발생률에미치는영향에대해후향적연구를통하여향후수두증의치료지침으로삼고자한다. 대상및방법 1. 대상 2002년 1월부터 2005년 12월까지뇌동맥류파열에의한뇌지주막하출혈에대해출혈후 3일이내의급성기에테리온접근법에의한동맥류경부결찰술을시행받은 141명을대상으로하였다. 전체환자는뇌동맥류수술중두개골절제술 (craniotomy) 직후시행한뇌실천자술을통해배액시킨뇌척수액의양에따라구분하였으며, 수술중뇌실천자술을시행하지않은제 1 군 (n=44) 과수술중뇌실천자술을통하여 40 cc 미만 (<40 cc) 의뇌척수액을배액시킨제 2 군 (n=34), 40 cc 이상 ( 40 cc) 의뇌척수액을배액시킨제 3 군 (n=63) 으로나누었다. 이연구에서 1) 파열되지않은동맥류에대해수술한경우, 2) 후방순환계 (posterior circulation) 에있는뇌동맥류에 대한수술의경우, 3) 급성기 ( 출혈후 3일이내 ) 에수술하지않은경우, 4) 테리온접근법을사용하지않은경우는제외하였다. 2. 수술방법및치료뇌동맥류파열에의한뇌지주막하출혈환자를대상으로테리온접근법을통해동맥류경부결찰술을시행하였고, 개두술전에뇌실외배액술 (extraventricular drainage) 이나요추배액술 (lumbar drainage) 을시행한환자는없었다. 수술중뇌실천자술은경막을연후에전두개와 (anterior cranial fossa) 상방 2.5 cm 지점과상실비우스정맥 (superior sylvian vein) 을기준으로하여실비우스열구 (sylvian fissure) 전방 2.5 cm 지점이직각으로만나는점에뇌표면으로부터 4~7 cm 깊이로뇌실도관 (ventricular catheter; Integra Neuro Care, Interga Life Science Co., Plainsboro, NJ, U.S.A.) 을삽입하여시행하였으며, 뇌척수액을배액시켜원하는정도의뇌이완을유도한후도관을제거하였다. 종말판 (lamina terminalis) 과 Liliequist막의창냄술 (fenestration) 이나뇌조배액관 (cisternal drain) 의설치는환자의뇌동맥류위치, 뇌부종의정도, 지주막하강내의출혈량, 뇌실내출혈여부등에따라결정하였다. 술후에는통상적인칼슘통로차단제투여와과혈용량요법 (hypervolemic therapy) 등으로적정의혈역학적상태를유지하면서보존적치료를시행하였다. 동맥류수술후뇌실-복강간단락술은첫째, 1) 뇌전산화단층촬영 (computed tomography : CT) 상뇌실의이마뿔 (frontal horn) 이원형으로변화된경우, 2) 제 3 뇌실과관자뿔 (temporal horn) 의크기가증가된경우, 3) 대뇌피질고랑 (sulcus) 의감소가있는경우, 4) 뇌실주위저음영이있는경우등방사선학적기준과둘째, 환자의의식장애, 보행장애, 요실금및기억력장애등의신경학적악화를포함한임상적기준을동시에만족하는경우로하였다. 수두증에대한수술은통상적인방법의뇌실-복강간단락술을시행하였다. 3. 자료분석전환자에대해관찰시점의나이, 성별, Hunt-Hess 등급, Fisher 등급, 글라스고우혼수계수 (Glasgow Coma Scale : GCS) 점수, 수술 3개월후글라스고우회복계수 (Glasgow Outcome Scale : GOS) 점수, 내원당시의수두증유무, 내원당시뇌실내출혈유무, 수술중뇌실천자술시행유무, 수술중뇌실천자술시행시배액시킨뇌척수액의양, 종말판창냄술시행유무, 뇌조배액관설치유무및뇌동맥류결찰술후뇌실-복강간단락술시행유무에대해의무기록을근거로후향적조사를하였다. 뇌지주막하출혈후결과
판정은수술 3개월후시행하였으며 GOS 1점은사망, 2점은지속적인식물인간상태, 3점은중증의장애 ( 의식은있으나불구상태 ), 4점은중등도의장애 ( 장애가있으나독립적으로행동가능 ), 5점은정상으로쾌유하여일상사로복귀한경우로하였다. 18) 수술중뇌실천자술시행시배액시킨뇌척수액의양이뇌실-복강간단락술시행여부에미치는영향에대해 chisquare 분석법으로세군간비교를하였고 Fisher의정확검정법 (Fisher s exact test) 으로사후검정하였다. 뇌실- 복강간단락술이필요한수두증에영향을줄수있는여러인자들중, 내원시급성수두증의동반유무, 수술중종말판창냄술시행유무, 뇌조배액관의설치유무, 내원시뇌실내출혈동반유무와같이뇌척수액의흐름에변화를줄수있는인자들에대해서도단변량분석 (univariate analysis) 을하였다. 이결과를바탕으로수술중뇌실천자술과만성수두증의발생연관성에대한강도를파악하기위해단변량분석에서의의가있는변수를후진로짓회귀분석 (backward logistic regression analysis) 을이용하여유의성을구하였다. 통계학적유의수준은 p-값이 0.05 이하인경우로결정하였으며각통계자료는평균치 ± 표준편차로표시하였다. 결과 1. 임상적특징총 141례중 97례 (97/141, 68.8%) 에서수술중뇌실천자술을시행하였으며, 수술중뇌실천자술을시행한군중 34례 (34/141, 24.1%) 에서 40 cc 이하의뇌척수액을배액시켰으 며, 63례 (63/141, 44.7%) 에서 40 cc 이상의뇌척수액을배액시켰다. 평균연령은제 1 군 (n=44, 31.2%) 이 54.2±11.7 세였고, 제 2 군 (n=34, 24.1%) 이 53.1±13.3세, 제 3 군 (n=63, 44.7%) 이 56.1±13.9세였다. 성별은총 141례중여자가 95명 (67.4%) 으로남자보다많은비율을차지하고있었으며, 세군간에통계학적으로유의한차이는없었다. 전체환자군에서뇌동맥류의위치는전교통동맥이 44.7% (63/141) 로가장높은비율을차지하고있었으며, 중대뇌동맥이 29.1% (41/141), 후교통동맥이 21.3% (30/141), 내경동맥이 3.5% (5/141), 전맥락막동맥과안동맥이각각 0.7% (1/141) 의빈도를보였다 (Table 1). 전체환자군에서 Hunt-Hess 등급은평균 3.06±0.91, Fisher 등급은평균 3.08±0.84, GCS 점수는평균 12.94± 3.15, GOS 점수는평균 4.28±1.44 이었으며, 세군간의뇌지주막하출혈의정도와신경학적척도에대한지수 (Hunt- Hess 등급, Fisher 등급, GCS 점수, GOS 점수 ) 에서는유의한차이가없었다 (Table 2). 2. 수술중뇌실천자술과수두증의발생수술중뇌척수액을배액시킨 97례에서배액된뇌척수액의양은 7 cc에서 82 cc까지였으며평균 31.78±26.42 cc를배액시켰다. 뇌실-복강간단락술은동맥류경부결찰후 19일에서 90일 ( 평균 37.3일 ) 사이에 25명 (17.7%) 의환자에서시행되었는데, 제 1 군에서 4명 (4/44, 1%), 제 2 군에서 6명 (6/34, 17.6%), 제 3 군에서 15명 (15/63, 23.8%) 의환자에서시행되었다. 수술중뇌실천자술시행에따른뇌척수액배액량에
대한뇌실-복강간단락술시행비율은세군간에유의한차이를보이지않았다 (p=0.146) (Fig. 1, Table 3). 내원시급성수두증을보이던환자가뇌실-복강간단락술을요하는수두증으로진행된경우는 65명중 15명으로 23% 에해당하였으며급성수두증의동반유무에대한단락술시행비율역시유의한통계학적차이를보이지않았다 (p=0.124). 종말판창냄술을시행한환자에서뇌실-복강간단락술을시행한경우는 67명중 15명 (22.4%) 으로종말판창냄술시행유무와단락술시행비율도통계학적으로유의한차이를보이지않았다 (p=0.168). 뇌조배액관을설치한환자에서만성수두증으로인해단락술을시행한경우는 15.1% (10/66) 로뇌조배액관에대한단락술시행비율또한유의한차이를보이지않았다 (p=0.452). 그러나뇌실내출혈이있는경우환자가뇌실-복강간단락술을요하는수두증으로진행된경우는 34명중 11명 (32.3%) 으로뇌실내출혈의동반유무에따른단락술시행비율은통계학적으로유의한차이를보였다 (p=0.010) (Fig. 2, Table 3). 다변량분석을통한각요소들에대한단락술시행비율에서도뇌실내출혈의동반유무에따른단락술시행비율만이통계학적으로유의한차이를보였다 (p=0.014). 고찰 동맥류파열에의한뇌지주막하출혈환자에서조기수술은재출혈의위험성을줄이고, 지주막하공간의혈괴를제거함으로써뇌혈관연축의진행을최소화하며, 뇌혈관연축발생빈도를줄이기위한과혈량요법등의보다적극적인치료를하기위해시행되어지고있다. 16)17) 그러나이러한급성기수술에서는뇌부종이동반되어있기때문에, 뇌견인에의한뇌손상을최소화하기위해수술전과수술중두개내압을감소시키는것이매우중요하다. 따라서수술중두개내압을감소시키기위해상황에따라수술전뇌실외배액술, 요추배액술또는수술중뇌실천자술등을통해뇌이완을유도함으로써뇌견인에따른손상을최소화하고있다. 1)5)13)22) 수술중뇌실천자술은 1988년 Paine 등 26) 에의해술기가발표되었으며뇌척수액의배액을통해뇌실감압을유도함으로써수술을용이하게하는데효과가커서테리온접근법에의한뇌지주막하출혈수술에널리사용되고있다.
이전여러연구들에따르면뇌지주막하출혈후수두증은흔하게발생하는중요한합병증이며이중단락술을요하는만성수두증은약 20% 정도로보고되고있다. 1)9)11)12)20) 본연구에서도 141명의환자중 25명 (17.7%) 에서단락술을시행하여여러문헌의보고에서와비슷한발생비율을나타내었다. 수두증의발생기전은발생시기에따라급성은실비우스수도, 제 4뇌실과뇌기저조에서혈괴에의한뇌척수액의순환장애혹은지주막과립 (arachnoid granulation) 에서의흡수장애에의해발생하고, 만성수두증의경우지주막과립의섬유화나폐쇄에의한뇌척수액흡수의영구적기능장애에의한다고알려져있다. 2-4)7)8)15)19)35) 급성수두증이만성수두증으로이행되기도하나반드시그러한것은아니어서급성수두증과만성수두증은서로다른기전에의해발생하는것으로알려져있다. 20) 뇌지주막하출혈후여러관련인자중에서도내원당시의신경학적등급, 연령, 지주막하출혈량과동맥류의위치, 저나트륨혈증, 고혈압및당뇨병, 항섬유용해제의사용등이수두증발생과직접적인연관이있다고알려져있다. 2)6)10)20)27-29)32)35) 이전연구중에서 Black 2) 은뇌지주막하출혈을갖는고령환자에서수두증이많이발생하였으며, 혈관연축과수두증을동반한경우가 62% 로밀접한관계가있다고보고하였다. Saveland 등 28) 은내원시 Hunt-Hess 등급과만성수두증사이에상관관계를보였다고하였으나, Morh 등 25) 은내원시의식수준과뇌실확장과는의미있는상관관계가없는것으로보고하였다. Demirgil 등 6) 은당뇨병의합병유무, Fisher 등급, 뇌실내출혈이수두증의발생에중요한역할을한다고주장하였으며, Sheehan 등 29) 은내원당시급성수두증의동반여부및내원시신경학적상태, 내원시뇌실내출혈동반여부외에도고혈압, 알코올중독여부, 여성, 동맥류의크기, 폐렴및뇌수막염등의감염증동반여부등이복합적으로영향을미친다고보고하였다. 또한 Kassell 등 21) 은뇌동맥류수술시기에대한전향적연구에서지연수술을시행한경우에뇌실-복강간단락술을필요로하는수두증의발생이높았다고보고하였으며, Ljunggren 등 23) 은조기수술로뇌기저조의혈괴를제거하는것이지주막하강의섬유화를줄이고, 뇌척수액의유통을좋게하여수두증의발생빈도를줄일수있다고보고하였다. 기존의많은연구들에서이미여러인자들에대해수두증의발생에미치는영향을통계학적으로입증하였으므로, 저자는지주막하강의섬유화에의한뇌실-복강간단락술이필요한교통성수두증 (communicating hydrocephalus) 과수술중뇌실천자술에따른뇌척수액배액량과의관계를통계분석하였다. 저자는비록전교통동맥류파열환자에국한된연구이나 Jeon 등 19) 이보고한종말판창냄술에의한뇌척수액의조기 배액이뇌실-복강간단락술을요하는만성수두증의발생빈도를증가시킨다는기존의연구결과를토대로수술중뇌실천자술을시행하게되면뇌실및뇌지주막하강내의뇌척수액이유출되고, 이로인해유효순환뇌척수액이감소되어급성기뇌조혈괴의세척효과를저하시켜혈괴의농축정도가증가되고, 뇌척수액의순환이느려져지주막하강의섬유화를촉진시켜뇌실-복강간단락술을필요로하는만성수두증의발생비율이증가될수있다는가설을세웠다. 그러나본연구결과뇌실천자술유무, 뇌실천자에의한뇌척수액배액량과단락술을요하는뇌수두증의발생간에는뚜렸한연관성이없어 Jeon 등 19) 이보고한연구와는상이한결과를보였다. 이는이번연구가전방순환계뇌동맥류환자전체를대상으로한연구이며, 또한수술중뇌실천자술과뇌조배액관설치를동시에시행한경우 (54/97, 55.7%) 가많아이전연구와는다른결과를보인것으로해석되었다. Hasan 등 14) 은급성수두증환자의 53% 이상에서뇌실내출혈은없었고뇌기저조에만출혈을보였다고보고하면서, 뇌기저조의혈액은뇌척수액의저항을증가시켜뇌실의압력은증가시키면서, 지주막융모주변에는압력을낮추어수두증이생긴다고설명하였으나대부분의기존연구에서저자들은뇌실내출혈이급성수두증발생의가장큰위험인자라고보고하였다. 1)7)10)31)33) 그기전은혈괴와뇌척수액의높은점성으로인하여뇌실의유출구를막아뇌척수액의흐름을저해하고뇌실내압력을증가시켜수두증이발생한다고하였다. 본연구에서도뇌실내출혈동반유무만이뇌실-복강간단락술이필요한수두증을일으키는요인으로통계학적의미가있었다. 이번연구에서수술중뇌실천자술은뇌실-복강간단락술이필요한수두증의발생비율에통계학적관계가없는것으로나타났다. 이결과를바탕으로판단해볼때수술중뇌실천자술시행후만성수두증의합병가능성은낮으므로, 수술을용이하고신속하게마치기위해수술중뇌실천자술을적극적으로고려하여야할것으로판단되었다. 하지만, 급성수두증동반유무, 종말판창냄술시행유무, 뇌조배액관의설치유무, 뇌실내출혈동반유무등에비해, 수술중뇌실천자술은뇌실및뇌조내뇌척수액의흐름에장기적인영향을미치지않을수있다는점이이연구의한계로판단된다. 또한뇌혈관연축동반유무및뇌부종의정도등뇌척수액과뇌혈류의흐름에영향을줄수있는요소들이고려되지않아연구모델에있어내부적한계가있다. 그러므로향후다수의환자를대상으로한환자-대조군연구 (casecontrol study) 나전향적인코호트연구 (prospective cohort study) 를통한통계학적연구가필요할것으로사료된다. 또한다수의술자에의한객관성있는뇌실천자술의적응증확립이필요하며, 이의병렬비교를통해외부적타당성
(external validity) 을높일수있을것으로기대된다. 결 뇌동맥류파열에의한뇌지주막하출혈수술시뇌견인에따른뇌손상을최소화하기위해수술중뇌실천자술이널리사용되고있다. 수술중뇌실천자술은별도의준비과정없이수술중빠르게두개내압을감소시켜서뇌이완을유도함으로써수술을용이하게할수있다는장점이있다. 저자는수술중뇌실천자술이수술후뇌실-복강간단락술이필요한수두증의발생에영향을주지않는다는사실을통계학적으로확인하였다. 결론적으로뇌동맥류파열환자에서수술중뇌실천자술은단락술이필요한만성수두증의발생을증가시키지않으므로, 뇌견인에의한뇌손상을최소화하고뇌부종에따른수술시간의지연을막기위해수술중뇌실천자술을적극적으로고려해야할것으로판단된다. 중심단어 : 뇌실천자술 단락술 수두증 뇌동맥류 뇌지주막하출혈. 01) Auer LM, Mokry M. Disturbed cerebrospinal fluid circulation after subarachnoid hemorrhage and acute aneurysm surgery. Neurosurgery 26:804-9, 1990 02) Black PM. Hydrocephalus and vasospasm after subarachnoid hemorrhage from ruptured intracranial aneurysms. Neurosurgery 18:12-6, 1986 03) Black PM, Tzouras A, Foley L. Cerebrospinal fluid dynamics and hydrocephalus after experimental subarachnoid hemorrhage. Neurosurgery 17:57-62, 1985 04) Choi JJ, Koh HS, Cho JH, Kim SH, Youm JJ, Song SH, Kim Y. Clinical study on risk factors of hydrocephalus after aneurysmal subarachnoid hemorrhage. J Korean Neurosurg Soc 30:1375-80, 2001 05) Connolly ES Jr, Kader AA, Frazzini VI, Winfree CJ, Solomon RA. The safety of intraoperative lumbar subarachnoid drainage for acutely ruptured intracranial aneurysm: technical note. Surg Neurol 48:338-44, 1997 06) Demirgil BT, Tugcu B, Postalci L, Guclu G, Dalgic A, Oral Z. Factors leading to hydrocephalus after aneurysmal subarachnoid hemorrhage. Minim Invasive Neurosurg 46:344-8, 2003 07) Doczi T, Nemessanyi Z, Szegvary Z, Huszka E. Disturbances of cerebrospinal fluid circulation during the acute stage of subarachnoid hemorrhage. Neurosurgery 12:435-8, 1983 08) Ellington E, Margolis G. Block of arachnoid villus by subarachnoid hemorrhage. J Neurosurg 30:651-7, 1969 09) Gjerris F, Borgesen SE, Sorensen PS, Boesen F, Schmidt K, Harmsen A, Lester J. Resistance to cerebrospinal fluid outflow and intracranial pressure in patients with hydrocephalus after subarachnoid haemorrhage. Acta Neurochir (Wien) 88:79-86, 1987 론 10) Graff-Radford NR, Torner J, Adams HP Jr, Kassell NF. Factors associated with hydrocephalus after subarachnoid hemorrhage. A Report of the Cooperative Aneurysm Study. Arch Neurol 46:744-52, 1989 11) Grant JA, McLone DG. Third ventriculostomy: a review. Surg Neurol 47:210-2, 1997 12) Gruber A, Reinprecht A, Bavinzski G, Czech T, Richling B. Chronic shunt-dependent hydrocephalus after early surgical and early endovascular treatment of ruptured intracranial aneurysms. Neurosurgery 44:503-9, 1999 13) Hasan D, Lindsay KW, Vermeulen M. Treatment of acute hydrocephalus after subarachnoid hemorrhage with serial lumbar puncture. Stroke 22:190-4, 1991 14) Hasan D, Tanghe HL. Distribution of cisternal blood in patients with acute hydrocephalus after subarachnoid hemorrhage. Ann Neurol 31:374-8, 1992 15) Hildebrandt G, Werner M, Kaps M, Busse O. Acute noncommunicating hydrocephalus after spontaneous subarachnoid haemorrhage. Acta Neurochir (Wien) 76:58-61, 1985 16) Hyun MH, Kim KM, Bak KH, Shin HS, Kim JM, Kim YS, Ko Y, Oh SH, Oh SJ, Kim NK. Clinical analysis of subarachnoid hemorrhage with intraventricular hemorrhage due to aneurysmal rupture. J Korean Neurosurg Soc 26:191-5, 1997 17) Inagawa T, Kamiya K, Ogasawara H, Yano T. Rebleeding of ruptured intracranial aneurysms in the acute stage. Surg Neurol 28:93-9, 1987 18) Jennett B, Bond M. Assessment of outcome after severe brain damage. Lancet 1:480-4, 1975 19) Jeon JY, Kim JM, Cheong JH, Yi HJ, Bak KH, Kim CH. Influence of lamina terminalis fenestration on the occurrence of the shunt-dependent hydrocephalus in anterior communicating artery aneurysmal subarachnoid hemorrhage. Korean J Cerebrovasc Surg 7:37-43, 2005 20) Joakimsen O, Mathiesen EB, Monstad P, Selseth B. CSF hydrodynamics after subarachnoid hemorrhage. Acta Neurol Scand 75:319-27, 1987 21) Kassell NF, Torner JC, Haley EC Jr, Jane JA, Adams HP, Kongable GL. The International Cooperative Study on the Timing of Aneurysm Surgery. Part 1: Overall management results. J Neurosurg 73:18-36, 1990 22) Kim JM, Chae YS, Cheong JH, Bak KH, Kim CH, Oh SH. Influence of routine intraoperative ventricular drainage on the incidence of aneurysmal rebleeding. J Korean Neurosurg Soc 36:18-23, 2004 23) Ljunggren B, Brandt L, Kagstorm E, Sundbarg G. Result of early operation for ruptured aneurysm. J Neurosurg 54:473-9, 1981 24) Milhorat TH. Acute hydrocephalus after aneurysmal subarachnoid hemorrhage. Neurosurgery 20:15-20, 1987 25) Mohr G, Ferguson G, Khan M, Malloy D, Watts R, Benoit B, Weir B. Intraventricular hemorrhage from ruptured aneurysm. Retrospective analysis of 91 cases. J Neurosurg 58:482-7, 1983 26) Paine JT, Batjer HH, Samson D. Intraoperative ventricular puncture. Neurosurgery 22:1107-9, 1988 27) Pietila TA, Heimberger KC, Palleske H, Brock M. Influence of aneurysm location on the development of chronic hydrocephalus following SAH. Acta Neurochir (Wien) 137:70-3, 1995 28) Saveland H, Hillman J, Brandt L, Edner G, Jakobsson KE,
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