Canad. Med. Ass. J.Jan. 1, 1966, vol. 94 Moyes: Ruptured Intracranial Aneurysms 13

Management and Surgical Treatment of RupturedIntracranial Aneurysms

PETER D. MOYES, M.D., F.R.C.S.[C], Vancouver, B.C.

ABSTRACTThe advantages, methods and results ofsurgical intracranial obliteration of aneur¬

ysms in conjunction with the use of intra¬cranial or neck ligation of arteries werestudied in 177 patients made up of thefollowing groups: (a) internal carotidaneurysms.48, (b) anterior cerebral.an¬terior communicating.37, (c) middle cere¬

bral.20, (b) basilar.two, (e) posteriorcerebral.one. The overall mortality ratewas 23%. Following conservative treat¬ment, 69 patients with subarachnoid hemor¬rhage without demonstrated aneurysmshad a mortality rate of 30%. In this seven-

year study the value of team work involv¬ing a second neurosurgeon, well-trainednursing personnel and expert anesthetistswas amply demonstrated.

rPHE treatment of ruptured intracranial aneur-¦*¦ ysms constitutes one of the most challengingareas in neurology and neurosurgery today. Advo-cated therapy has ranged from strictly medicaltreatment of all patients.irrespective of the age ofthe patient, site of aneurysm, or severity and fre¬quency of rupture.to surgical treatment with deephypothermia and total arrest of circulation.

Current Concepts est Aneurysm Surgery

Despite McKissock, Paine and Walsh's1 con-clusion that there is no proof that the results ofsurgical treatment are any better than those ofconservative treatment in comparable groups ofpatients, most neurosurgeons, rightly or wrongly,believe that the results of surgical treatment arebetter and that the additional security and freedomfrom physical restrictions resulting from successfulsurgical treatment are further factors worthy ofconsideration.Some facts with regard to subarachnoid hemor¬

rhage have become clear:1. There is a high early mortality. We are not

likely in the immediate future to reduce the num¬ber of deaths that occur in the first 24 hours afterhemorrhage except in those patients in whomlocalized hematoma is present.

SOMMAIRE

L'auteur a etudie sur 117 patients lesavantages, methodes et resultats de Te-limination chirurgicale d'anevrismes intra-craniens, associee a la ligature d'art&resintracraniennes ou cervicales. Les maladesont ete repartis dans les groupes suivants:(a) anevrismes de la carotide interne 48 cas,(b) cerebrale anterieure et communicanteanterieure 37 cas, (c) c£r£brale moyenne 20cas, (d) basilaire deux cas, (e) c£r£braleposterieure un cas. La mortalite globale aet6 de 23%. Apres traitement conservateur,chez 69 malades atteints d'hemorragie sous-arachnoidienne sans evidence d'anevrismes,la mortalite a atteint 30%. Cette &ude,qui a couvert une periode de sept ans, a

permis de d£montrer amplement la valeurdu travail d'equipe comportant la presenced'un second neuro-chirurgien, de personnelinfirmier competent et d'anesthesistes bienentrain£s.

From the Department of Surgery (Neurosurgery), Universityof British Columbia, Vancouver, B.C.Presented in part at the 34th Annual Meeting of the RoyalCollege of Physicians and Surgeons of Canada, Toronto,January 23, 1965.

2. The more severe the hemorrhage and theworse the basic health of the patient, the worseare the results of any kind of treatment.

3. Except when a localized hematoma is present,the purpose of surgical intervention is to preventfurther hemorrhage, not to treat the currentepisode.

4. Patients who survive a subarachnoid hemor¬rhage and in whom no aneurysm can be demon¬strated, despite adequate visualization of bothcarotid and both vertebral arteries and theirbranches, appear to have a good prognosis.2"4

5. Vasospasm is one of the major factors, if notthe major factor, responsible for mortality andmorbidity, and an adequate method of dealing withthis response would undoubtedly greatly enhanceour ability to deal with ruptured aneurysms.

Certain techniques are being developed andapplied to the treatment of intracranial aneurysmssuch as electrocoagulation,5 pilojection,6 intra¬luminal manipulations7 and deep hypothermia.8*9One or more of these techniques may provesuperior to those presently in general use but validconclusions cannot yet be drawn about them. How¬ever, differences of opinion exist concerning thetechniques now generally available, and this com¬munication will outline my attempts to use, to thebest possible advantage, one or more of the follow¬ing methods: intracranial obliteration of the

14 Moyes: Ruptured Intracranial Aneurysms Canad. Med. Ass. J.Jan. 1, 1966, vol. 94

aneurysm, reinforcement of the aneurysm bymuscle, muslin or plastic material, and ligation ofa proximal artery.either intracranially or in theneck.

Management of Intracranial Hemorrhageat the Vancouver General HospitalWhen a patient with a suspected subarachnoid

hemorrhage is seen by one of the members of theNeurosurgical Service of the Vancouver GeneralHospital, he or she is assessed clinically and thediagnosis is confirmed by lumbar puncture usinga small-gauge needle and obtaining only a smallamount of cerebrospinal fluid. When doubt exists,xanthochromia or the presence of crenated redblood cells in the spinal fluid will usually providepositive confirmation.

If the patient has focal signs compatible with anintracerebral hematoma, carotid arteriography iscarried out as soon as possible and is followed bycraniotomy if indicated. Otherwise the patient iswell sedated if restless, and the blood pressure isreduced by a moderate amount if elevated. He ismaintained on complete bed rest and may becatheterized. The nursing care during this periodis very important. Carotid arteriography is carriedout within 24 to 48 hours and should includeoblique views and cross-compression when ananterior communicating aneurysm is suspected. Ifno aneurysm is discovered at this examination,vertebral arteriography is carried out in 48 hours;open brachial retrograde arteriography, as de¬scribed by Kuhn,10 is usually done.When the aneurysm is located, another neuro-

surgeon on the service is called upon to help de-cide whether or not operation should be carriedout, what type of operation should be done andwhen it should be done. He also assists at theoperation.

I agree with Pool11 that operation should becarried out within seven days of hemorrhage if thecondition of the patient warrants it, because thedanger of recurrent hemorrhage beyond this timeis considerable. In the interim, the patient is main¬tained on complete bed rest and is well sedated.

Various factors must be considered when decid-ing on the timing of surgical intervention in a pa¬tient with rupture of an intracranial aneurysm.Despite the fact that the danger of recurrenthemorrhage is great beyond seven days, it is stilldifficult to decide whether or not to operate in thefirst seven days because vascular spasm is greaterduring this period than it is several weeks later.provided recurrent hemorrhage has not occurred.The operation is done to prevent recurrent hemor¬rhage but, in fact, often increases the degree ofspasm and this spasm is the principal factor inpostoperative mortality and morbidity. The timingof operation is therefore decided after weighingthese two factors: If, on clinical and radiographicalgrounds, considerable spasm seems to be present,

one would be inclined to wait longer than seven

days; if it is slight, one would proceed within theseven-day period.

It must be remembered that, except when a

significant intracranial hematoma is present,attempts to prevent recurrent hemorrhage maycause further damage by virtue of retraction ofalready swollen brain, and manipulation of alreadyspastic arteries.The reason why the presence of hematoma alters

the situation with respect to timing is because suchhematoma constitutes a space-occupying mass,which may increase in size owing to osmotic attrac¬tion of fluid. Since this mass can be removedsurgically, its removal is usually highly beneficialand this benefit is likely to be greater than the dis-advantage of possibly increasing spasm.

Fig. 1..Patient in position with the scalp flap markedand the collar incision for carotid exposure already made.The patient is lying on her back with her head turned 45°to the left.

Operation is carried out under hypothermia,using a temperature of about 84° F. attained bymeans of a cooling blanket. Hyperventilation andthe intravenous administration of urea or mannitolare also used to shrink the brain and allowmaximum exposure with minimum retraction. Thecarotid arteries are exposed in the neck for intra¬cranial operations on carotid and anterior com¬

municating aneurysms, but not for procedures on

middle cerebral aneurysms in which a Mayfieldclip can be applied to the middle cerebral arteryitself for temporary occlusion. As soon as theaneurysm has been obliterated, re-warming iscommenced and hyperventilation is discontinued.Papaverine is applied locally to the vessels inproximity to the aneurysm. Some of the features ofa procedure carried out for the control of an

aneurysm of the right internal carotid artery are

illustrated in Figs. 1-3.

Case MaterialThe case material presented in this communica¬

tion was that seen over a period of seven years

Canad. Med. Ass. J.Jan. 1, 1966, vol. 94 Moyes: Ruptured Intracranial Aneurysms 15

Fig. 2..View obtained with the right frontal lobe retractedto expose (from.left to right) the right optic nerve, theinternal carotid artery with the aneurysm projecting postero-laterally from it, and the third nerve in close lateralproximity to the aneurysm.

Fig. 3..The same view as that illustrated in the previousphotograph, showing an Olivecrona clip occluding the neckof the aneurysm.

and consists of 108 cases in which aneurysms were

proved and 69 in which subarachnoid hemor¬rhages occurred but in which no aneurysms were

found: a total of 177 cases. With respect to evalua¬tion, the patients have been divided into fourcategories: good.no significant residual neuro¬

logic deficit; fair.significant neurologic deficitbut able to lead essentially normal lives.that is,they have resumed previous employment or

management of a household; and poor.unableto resume their previous occupation. In a fourthcategory are patients who died as a result of theaneurysm no matter how long after operationdeath occurred (Table I). There were many more

women than men in this series and although thisis common to other studies, we have an usuallyhigh percentage of women.Our mortality rate of 23% in a group of surgically

treated patients with ruptured berry aneurysms mayseem high. However, in other studies where onlyideal patients were chosen for surgery and wherea lower surgical mortality rate obtains, proportion-ately greater numbers of patients died preopera¬tively than died in this group, thereby raising theoverall mortality. Hence the end result is much thesame.

TABLE I..Proved Berry Aneurysms

Total 108> Male 28, Female 80Not surgically treated. 25

Good. 2Fair. 1Poor. 1Died. 21

Intracranial operations. 78Good. 49Fair. 6Poor. 5Died. 18

Mortality rate.23%Carotid ligation in neck. 5

Good. 2Fair. 1Poor. 1Died. 1

Multiple AneurysmsEleven patients had multiple aneurysms; the

largest number of aneurysms in a single patientwas five. At postmortem examination, two patientswere found in whom rupture of more than one

aneurysm had occurred. In two patients, two

aneurysms were attacked intracranially at separateoperations. One is doing well and the other is blindas a result of vitreous hemorrhages which occurredat the time of the intracranial bleeding. In anotherpatient two aneurysms were attacked at the same

operation but further hemorrhage occurred fromone of the aneurysms which had been wrappedbut not occluded, and the patient died.

In this entire series, only those patients who re-

fused operation, or were considered unsuitable foroperation, were not treated surgically. By andlarge, they constituted a poor-risk group and theresults in these patients (Tables I, II, III and IV)are not representative of the results obtained in thenon-surgical treatment of ruptured aneurysms.

Internal Carotid AneurysmsThese involved either the posterior communicat-

ing artery or the bifurcation of the carotid artery,and were the commonest type in this series (Figs.4 and 5). They sometimes presented in associdtionwith a third-nerve palsy and occasionally withcontralateral hemiparesis, but very often there wereno localizing signs. Patients in this group are some¬

times considered for ligation of the carotid arteryin the neck without intracranial obliteration. Thismethod is more effective when the aneurysm is so

far proximal on the intracranial position of theartery that difficulty may be experienced in gettingaround the neck of the aneurysm.

In one patient an internal carotid aneurysm was

obliterated intracranially but it was evident thatthis area had not been the source of the hemor¬rhage. Subsequent vertebral arteriography demon¬strated an aneurysm of the posterior inferior cere-

bellar artery. This patient refused a second opera¬tion at the time but after moving away from Van¬couver had a further subarachnoid hemorrhageand the aneurysm was successfully obliterated. In

16 Moyes: Ruptured Intracranial Aneurysms Canad. Med. Ass. J.Jan. 1, 1966, vol. 94

Fig. 4..Arteriogram showing an internal carotid aneurysmof the type sometimes referred to as a posterior communicat-Ing aneurysm.

another patient a wrapping procedure was carriedout and a further mild hemorrhage followed sixweeks later. The carotid artery was then occludedin the neck and she has since done well. In a thirdpatient with a third cranial nerve palsy an internalcarotid aneurysm was ligated but at operation theaneurysm did not appear to have been compressingthe nerve.

TABLE II..Internal Carotid AneurysmsTotal 48, Male 9, Female 89

Not surgically treated. 9Good. 1Fair. 1Poor. 1Died. 6

Intracranial operations. 34Good. 23Fair. 1Poor. 1Died. 9

Mortality rate.27%Carotid ligation in neck. 5

Good. 2Fair. 1Poor. 1Died. 1

During operation, several patients with internalcarotid aneurysms died because the aneurysm hadbeen sheared off from the parent trunk, leaving ahole in the arterial wall, and ligation of the arteryhad been necessary to control hemorrhage. Whenimproved patching techniques such as that de¬scribed by Carton, Heifetz and Kessler12 are em¬

ployed, ligation of the parent artery will probablynot often be necessary in the future.The treatment of some carotid aneurysms situated

in a somewhat postero-medial position should beeither carotid ligation in the neck alone or carotidligation followed by intracranial ligation or rein-forcement.

Fig. 5..Arteriogram on the same patient after obliteratingthe neck of the aneurysm with an Olivecrona clip. This wasan uncomplicated operation, yet marked spasm of the carotidartery just proximal to the aneurysm can be seen.

Vasospasm will continue to cause death in some

patients in this group until it can be satisfactorilyovercome. It is usually present in the arteryadjacent to the aneurysm but it can also be fairlygeneralized throughout the intracranial arteriesand is often increased by operative manipulationduring ligation of the aneurysm. Its exact cause isnot known, but it is probably a protective mechan¬ism induced by blood in the cerebrospinal fluid or

by the aneurysm itself, and is accentuated byoperative maneuvers; in brief, it is a result of acombination of factors known and unknown. What¬ever the cause, postoperative deaths are attributedmore often to vascular spasm than to any otherfactor.

Anterior Cerebral.Anterior CommunicatingAneurysmsIn four patients in this group (Table III)

wrapping procedures were carried out to strengthenand protect the walls of aneurysms which seemedtoo large to obliterate. Muscle was used in theearlier cases but recently I have used methacrylateas described by Dutton.13 Three of the four are

doing well. One died following recurrent hemor¬rhage a few days later after operation. I have some-

TABLE III..Anterior Cerebral.Anterior Communica-ing Aneurysms

Total 37, Male 12, Female 25Not surgically treated.All 8 diedIntracranial operations

Good.. 18Fair. 2Poor. 2Died.. 7

Mortality rate.24%

Canad. Med. Ass. J.Jan. 1, 1966, vol. 94 Moyes: Ruptured Intracranial Aneurysms 17

Fig. 6..Marked vasospasm associated with an anteriorcommunicating aneurysm before operative intervention.

times placed a clip across the aneurysm at a siteother than the neck of the aneurysm if it appearedthat clamping of the neck (i.e. near the parentartery) would jeopardize the patency of theanterior cerebral arteries. One of the four patientsmentioned above did well after operation butsuffered a further hemorrhage at home as 'a resultof rupture of the aneurysm proximal to the clip.In similar situations I now usually reinforce thewhole aneurysm with methacrylate.

However, the greatest difficulties experienced inthis group of 37 patients (Table III) were relatedto vasospasm, and operation is usually deferredwhen the clinical and/or arteriographic findings are

suggestive of vasospasm (Figs. 6 and 7). Theblood pressure is held at a level approximately20% below the patient's normal systolic pressureuntil the clinical status has improved, unless re¬

current hemorrhages indicate that there is lessdanger in operating. It is in this particulargroup that the team approach afforded by thesecond neurosurgeon and specialized nursingfacilities has been most helpful and successful.

Middle Cerebral AneurysmsMore often than in other vessels middle cerebral

aneurysms are associated with localized neurologicdeficit, characterized by varying degrees of hemi-paresis, and occasionally, when the dominant hemi¬sphere is involved, the patient is also dysphasic.Two patients in this group of 20 (Table IV and

Fig. 8) had not had recent subarachnoid hemor¬rhage but one had suffered a serious hemorrhagesome years previously and his aneurysm was judgedto have increased in size in the interim.

In addition to the patients included in the fore¬going tables, during this seven-year period I en¬

countered two patients with basilar aneurysms,both of whom died without having had operativeintervention, and one patient who had an aneurysmof the posterior cerebral artery. In this last patient,

Fig. 7..An example of diminished vasospasm in the samepatient as Fig. 6 following obliteration of the aneurysm.

Fig. 8..A typical aneurysm at the trifurcation of the leftmiddle cerebral artery.

18 Moms: RUPTURED INmAa..aAL ANEURYSMS Canad. Med. Ass. J.1, 1966, vol. 94

TABLE IV.-MIDDLE CEREBRAL ANEURYSMS

Total 20, Male 5, Female 15Not surgically treated.

Good..6Died.5

Intracranial operations..14Good.8Fair.2Poor.2Died.2

Mortality rate-14%

the posterior cerebral artery was ligated just proxi-mal to the aneurysm with very little subsequentneurologic deficit.

Sui.1.cINom HEMORRHAGE WITHOUTDEMONSTRATED ANEURYSMS

In this group of patients with subarachnoidhemorrhage but without demonstrated aneurysm,the mortality rate was 30%. At postmortem ex-animation only rarely were very small discreteaneurysms found and in most cases the source ofthe bleeding was not revealed.

TABLE V.-SUBARACHNOID HEMORRHAGE WITHOUT DEMON-STRATED ANEURYSMS

Total 69, Male 24, Female 45Conservative treatment..66

Good.39Fair.4Poor.4Died.19

Mortality rate-30%Surgically explored.

Good..3-Died.1

There are two theories as to the mechanism ofsubarachnoid hemorrhage without demonstrablesource. One is that the aneurysm bleeds and thenbecomes thrombosed, in which case the patienttheoretically should survive. The second theory,which postmortem examination tends to support, isthat a small aneurysm actually destroys itself duringthe* bleeding and the hole seals itself off.

Microarteriography to demonstrate vessels in-visible to standard carotid arteriography is in theprocess of development, but whether such lesionsare amenable to surgical attack with our presentsurgical techniques is not yet clear.

In the last three patients in Table V, in whomexploration was carried out because aneurysmswere thought to have been demonstrated arterio-graphically, no aneurysm was found at operation.

DIscussIoN

The results of any form of treatment dependupon - many factors. The overall mortality rate of23% for the group subjected to intracranial surgeryseems high, but this is due in part to the policythat every patient was operated upon whosechances of survival were considered to be greaterwith surgical intervention than without.

In my experience, the influence of age, presenceand degree of vascular hypertension, severity ofhemorrhage and degree of vascular spasm is thesame as that described by Botterell et al.14 exceptthat the chronological age of the patient seems lessimportant than is sometimes stated. For example,one patient, aged 70, had successful obliteration ofan anterior communicating aneurysm: he wasexceptionally healthy and had no evidence ofatherosclerosis in either cerebral or other vessels.In other words, the health of the vessels is moreimportant than the chronological age of the patient.The patients least suitable for surgical treatment

are often those least suitable for an aggressivehypotensive regimen, but the judicious inductionof moderate hypotension is a valuable adjunct inthe management of these patients.There is no single ideal intracranial approach to

any particular type of aneurysm. A considerationof the various approaches has been omitted fromthis discussion because each neurosurgeon will usethe approach that is most suitable for him.

Specific ways in which present results of treat-ment can be improved have been mentioned, butthe most important lesson I have learned concernsthe value of the team approach in which a secondsurgeon helps in the management of the patient,well-trained nurses are on hand in the ward andin the operating room, and good anesthesia hasbeen assured. The results that can be achieved withtechniques now generally available can be quite en-couraging and rewarding.

SUMMARY

The results of treatment of 177 patients including108 patients with proved intracranial aneurysms arereported. The overall mortality rate among 78 pa-tients who had intracranial operations was 23%.A concerted team approach is advocated in the

management of each patient in order to achieve maxi-mum benefit from the methods of treatment at preseiltgenerally available.

I wish to thank Drs. F. A. Turnbull, P. 0. Lehmann,J. W. Cluff and G. B. Thompson for their help in thetreatment of the patients referred to in this report.

REFERENCES

1. McKlssocK, W., PAINE, K. W. E. AND WALSH, L. S.:J. Neurosurg., 17: 762, 1960.

2. PARKINSON, D.: Ibid., 12: 565, 1955.3. DUNSMORE, R. H. AND POLCYN, J. L.: Ibid., 13: 165, 1956.4. BJ6RKESTEN, G. AS'. AND TROUPP, H.: Ibid., 14: 434, 1957.5. MIJLLAN, S.: Induced thrombosis in an aneurysm, paper

presented at the Harvey Gushing Society Meeting, LosAngeles, April 20-22, 1964.

6. GALLAGHER, J. P.: J. Ncurosurg., 21: 129, 1964.7. LUESSENHOP, A. J. AND VELASQUEZ, A. C.: Ibid., 21: 85,

1964.8. USHLEIN, A. et al.: Ibid., 19: 237, 1962.9. MACCARTY, C. S., MICHENFELDER, J. D. AND UIHLEIN, A.:

Ibid., 21: 372, 1964.10. KUHN, R. A.: Ibid., 17: 955, 1960.11. PooL, J. L.: Ibid., 19: 378, 1962.12. CARTON, C. A., HEIPETE, M. D. AND KESSLER, L. A.: Ibid.,

19: 887, 1962.13. DUTTON, J.: Brit. Med. .T., 2: 597, 1959.14. BOTTERELL, E. H. et al.: .T. Neurosurg., 15: 4, 1958.