Aneurysm

Arising

at the

Triplicate

Communicating

Anterior

Artery

Case Report— — Tatsuhito

YAMAGAMI, Haruhiko KIKUCHI*, Kenichiro HIGASHI, Hajime HANDA and Jun MINAMIKAWA*

Department *Department

of Neurosurgery, of Neurosurgery

Ijinkai Takeda General Hospital, Kyoto; , Kyoto University Medical School, Kyoto

Abstract A very rare

case of triplicate

21-year-old

female

angiography, with

is reported.

but

found

no neurological

Key words: triplicate

communicating

The triplicate

intraoperatively.

artery

associated

configuration

was not

aneurysm

was trapped

The

with

predicted

ruptured

aneurysm

by preoperative

successfully,

in a

cerebral

and she recovered

deficit.

anterior anterior

anterior

communicating

communicating

artery,

vascular

anomaly,

ruptured

aneurysm,

artery

Introduction Vascular anomalies of the anterior communicating artery (AComA) include duplication or fenestration, duplication of the proximal anterior cerebral artery (A, portion), and the presence of the median artery of the corpus callosum or azygos anterior cerebral artery. `-5,7,9) Duplication of the AComA occurs in about 5 10% of operative cases of AComA aneurysm. However, a triplicate AComA is extremely rare. We report our experience with such a case. Case

Report

A 21-year-old female suffered a sudden onset of severe headache and vomiting. On admission, she was alert and well oriented. Neurological examina tion revealed no cranial nerve paresis, motor weakness, or nuchal rigidity. Computed tomogra phic scans disclosed a thin high-density area in the right chiasmatic cistern and Sylvian fissure. Cere bral angiograms revealed a small aneurysm of the AComA projecting downward (Fig. 1). Her preoperative clinical status was grade I on the Received 1991

March

19,

1991;

Accepted

October

21,

Fig. 1

Right carotid angiogram, aneurysm of the AComA ward (arrow).

showing a small projecting down

Hunt and Kosnik scale. An immediate right fron totemporal craniotomy demonstrated the aneurysm developing from the triplicate AComA near the left anterior cerebral artery (Fig. 2). Separation of the tri ple branches

and

dissecting

the aneurysmal

neck

Fig. 2

Intraoperative the AComA. branches.

photograph (left) and its schematic drawing (right), showing triplicate branching of The downward-projecting aneurysm has developed at the junction of the three

were very difficult. Since some bleeding occurred from the AComA, the aneurysm was trapped. As a result, the triple branches and one perforator were sacrificed. She was drowsy for 3 days afterwards, but her postoperative course was uneventful. Postoperative cerebral angiograms showed the aneurysm had com pletely disappeared and good visualization of the bilateral anterior cerebral arteries. She was dis charged on 30th postoperative day and has been asymptomatic at 2-year follow-up.

Discussion The AComA develops in the human fetus at about 44 days. The crown-rump length is 20-24 mm and AComA may be duplicated.' In adults, the AComA is usually single (classic type), but may be multiple (variant or nonclassic type).') De Almeida3) described 20 variant arterial con figurations, with two examples of triplicate AComA. Wollschlaeger et al.') studied 291 cases of abnormal AComA, of which one was absent and 42 were duplicated. They reported the triplicate form, which they termed "tripling," but did not give an inci dence. Baptista's series 2 of 504 cases showed that AComAs very frequently have a double or multiple form. He found one complex AComA of the multi ple type which presented a triplicate form, similar to that in our patient. The correlation between AComA aneurysm and

arterial anomalies has frequently been demon strated. Kwak et al.') reported 17 cases of fenestra tion and 13 of abnormal vessels among 296 cases of single AComA aneurysm. Seven of the 13 abnormal vessels were median arteries of the corpus callosum. Suzuki et al.'' found that 44 of 208 cases of AComA aneurysm (21.2%) had vascular anomalies. Duplication of the AComA was present in 20 cases (9.6%). They found that correct diagnosis of dupli cation of the AComA and proximal anterior cere bral artery was difficult based only on preoperative cerebral angiography. We also could not predict the anomaly in our case preoperatively. A complete preoperative diagnosis of anomalies associated with AComA aneurysm is probably impossible. Thus, it is important to assess the anatomical relationship between the AComA aneurysm and the surrounding vascular structure, especially when anomalies are discovered during surgery. References 1)

2)

3)

4)

Baptista AG: Studies on the arteries of the brain. II. The anterior cerebral artery: Some anatomic features and their clinical implications. Neurology (Minneap) 13: 825-835, 1963 Baptista AG: Studies on the arteries of the brain. III. Circle of Willis: Morphologic features. Acta Neurol Scand 40: 398-414, 1964 De Almeida F: Note sur les collatérales de l'artère com mnicante cérébrale antérieure. Arch Anat Antrop Lisboa 13: 551-556, 1931, cited in 4) Krayenbuhl HA, Yasargil MG: Cerebral Angiog

raphy,

5)

6)

7)

8)

ed 2. London,

Butterworths,

1968,

pp 51-54

Kwak R, Niizuma H, Hatanaka M, Suzuki J: Anterior communicating artery aneurysms with associated anomalies. J Neurosurg 52: 162-164, 1980 Padget DH: The development of the cranial arteries in the human embryo. Contr Embryol Carneg Instn 32: 205-261, 1948 Suzuki M, Ogawa A, Kayama T, Sakurai Y, Suzuki J: Vascular anomalies associated with anterior com municating aneurysms. No Shinkei Geka 16: 498-502, 1988 (in Japanese) Taveras JM, Wood EH: Diagnostic Neuroradiology, vol 2. Baltimore, Williams & Wilkins, 1977, pp 591-

598

9)

Wollschlaeger G, Wollschlaeger PB, Lucas FV, Lopez VF: Experience and result with postmortem cerebral angiography performed as routine procedure of the autopsy. Amer J Roentgen 101: 68-87, 1967

Address reprint ment of Hospital, ku, Kyoto

requests to: T. Yamagami, M.D., Depart Neurosurgery, Ijinkai Takeda General 28-1 Moriminami-cho, Ishida, Fushimi 601-13, Japan.