Traumatic Epidural Arterio-Venous Aneurysm Report of 2 Cases

CHARAS SUWANWELA, M.D. Neurosurgical Unit, Chulalongkorn Hospital Medical School, Bangkok, Thailand

It is well known that simultaneous injury to an ing from the region of the spheno-parietal ridge, upward adjacent artery and vein may produce an arterio- and posteriorly along a fracture line to the vertex. The venous fistula. Extensive reviews of traumatic middle meningeal artery was accompanied by 2 con- comitant veins. In the last fihn (Fig. 3), when the con- carotid cavernous fistula have been made. TM trast me,lia had disappeared from the arteries, some Arterio-venous or cirsoid aneurysms of the scalp remained in the dilated channels which were seen to have been proved to be of traumatic origin in empty into a lateral lacuna of the superior sagittal some cases. sinus. In the auteroposterior projection (Fig. 4) the When temporal or parietal bones are fractured, abnormal collection of media was close to the inner injury to the middle meningeal artery and its table of skull. branches may result in epidural hemorrhage. In Three days later common carotid arteriography was 1964, Kuhn and Kugler 5 reported the occurrence done and 11o abnormality was seen in tlle arterial phase of a false aneurysm of the middle meningeal artery (Fig. 5). The arterio-venous aneurysm was seen in the following temporal fracture. Jackson and du late arterial through venous phases but it was of much less clarity because the filling was fainter and was Boulay ~ in 1964, reported a case of arterio-vencus masked by the normal cerebral vessels. fistula between the middle meningeal artery and Operation. On March 21, 1964, a craniectomy was the diploic vein, in association with a linear frac- done along the temporal wing of the fracture. Thin or- ture of left parietal bone. ganized clotted epidural hematoma approximately The present communication is a report of 2-3 mm. thick was found. In the clot there were thin- cases of traumatic arterio-venous fistula between walled vascular channels, 3-6 ram. wide, containing the middle meningeal artery and dural veins arterial blood. The vascular channels extended upward draining into the superior sagittal sinus. and drained into the lateral lacuna of the superior sagittal sinus. Electrocoagulation controlled part of the bleeding from the lesion. The channels converged at the Case Reports spheno-parietal ridge where the middle meningeal artery Case 1. A 38-year-old Thai man was admitted to the was found. All bleeding from the vascular channels Chulalougkorn Hospital, Bangkok on March 16, 1964, stopped when the middle meningeal artery was ligated. complaining of headache. Ten days previously he had Postoperative Course. The postoperative course was been hit on the head with an axe and was unconscious uneventful. Repeat carotid arteriography 10 days after for approximately 1 hour. When he awoke, he was con- the operation showed no abnormal blood vessel. The fused and complained of headache. He was treated at a patient gradually improved and was able to return to local hospital where 2 small scalp wounds were sutured. work 1 month later. The wounds healed well but the mental confusion and headache persisted. Examination. On admission the patient was ambula- tory but markedly disoriented. Vital signs were normal. There was moderate stiffness of the neck and a positive Kernig's sign. No other abnormal neurological signs were present. The eye-grounds were normal. Roentgenograms of the skull (Fig. 1) showed stellate fractures of right frontal and parietal bones with up- ward extension into the diastatic sagittal suture and downward to the temporal region. Right carotid arteriography was performed; the ex- ternal carotid artery was inadvertently punctured and there was little filling of the internal carotid artery. In the lateral projection, the first film showed filling of the branches of the external carotid artery. The middle meningeal artery was seen as far as the proximal intra- cranial portion and was much enlarged. An abnormal pool of contrast media was seen around this intracranial part of the middle meningeal artery. The abnormality was better seen in the film taken half a second later (Fig. 2). Irregularly shaped chamlels were seen extend- Fie. 1. Case 1. Roentgenogram of the skull showing Received for publication May 21, 1965. stellate fracture of right frontal and parietal bones.

576 Traumatic Epidural Arterio-Venous Aneurysm 577

Fro. ~. Case 1. External carotid arteriography show- FIG. 3. Case 1. Venous phase of external carotid ing abnormal vascular channels extending from the arteriography showing contrast media in the vascular sphenoparietal ridge to vertex, and simultaneous filling channels draining into tile superior sagittal sinus. of the middle meningeal artery and its concomitant veins. arteriography which revealed no filling of either scalp or epidural arterio-venous aneurysms. Opsration. On July ~, 1964, an operation was done. Case 2. A -O4-year-old Thai bank clerk was admitted The arterio-venous aneurysm of the scalp was totally re- on July 10, 196~, because of mental confusion. Twelve moved after ligation of the superficial temporal artery. days previously he had fallen from a motorcycle and Craniectomy revealed a thin epidural hematoma and had hit the left side of his head on the ground. He was thin-walled vascular channels containing arterial blood unconscious for a few minutes and remained markedly and bleeding easily. The craniectomy was extended to- confused. In the left fronto-parietal region there was a wards the spheno-parietal ridge and the middle menin- swelling on the scalp, which gradually increased in size (Fig. 6). Examination. On admission he was ambulatory, but agitated and disoriented. Over the left fronto-parietal region there was a purplish swelling of about ~ to 3 cm. in diameter without pulsation or bruit. The knee jerk was brisker on the left. The rest of the physical and neurological findings were normal. Roentgenograms of the skull (Fig. 7) showed a linear fracture in the region of left coronal suture. Carotid arteriography by percutaneous puncture of the left common carotid artery (Fig. 8) revealed marked en- largement of the superficial temporal and middle meningeal arteries. There was an arterio-venous aneu- rysm in the scalp in the fronto-parietal region which was fed by the large tortuous superficial temporal artery. There was also a collection of contrast medium typical of an aneurysm in the fronto-temporal region which showed in the anteroposterior projection (Fig. 9) just under the skull. The cortical vessels were seen separating from the inner table of the skull, leaving an avascular slit about 5 mm. thick in the fronto-temporal region. In a later phase an abnormal collection of contrast mediuln was seen about the region of the linear fracture. It appeared as a channel 5 or 6 mm. wide with many outpouchings, from the spheno-parietal ridge upward and posteriorly in the lateral view (Fig. 10). In the antero-posterior projection (Fig. 11) the dilated channel was situated along the medial aspect of the avascular slit. FIo. 4. Case 1. Anteroposterior projection of Fig. The angiographic needle was advanced into the in- showing abnormal filling close to the inner table of ternal carotid artery for a selective internal carotid skull (arrow).