A new microsurgical revascularizationtechnique for anterior cerebral artery
ischemia is reported. An arterial graft bypass interposed between the
superficial temporal artery and the distal anterior cerebral artery was
successfully completed in a 43-year-old male with transient ischemic attacks
in the anterior cerebral artery territory. The contralateral superficial temporal
artery was harvested and used as an arterial graft. Both procedures were
carried out with one single transcoronal scalp incision. The patient’s
postoperative cerebral angiogram reve,aled good filling of the area distal to
the stenotic lesion of the anterior cerebral artery through the bypass graft.
The patient was discharged with no neurological deficit and has been free of
ischemic events for more than 2 years since the surgery. If the bilateral
superficial temporal arteries are fairly well developed, the ipsilateralsuperficial
temporal artery can be used as an arterial graft for revascularization of the
anterior cerebral artery territory.
MICROSURGERY 9: 14-1 7 1988

A N INTERPOSED SUPERFICIAL TEMPORAL ARTERY GRAFT
BYPASS FOR ANTERIOR CEREBRAL ARTERY ISCHEMIA
YOSHIKAZU IWATA, M.D., TADAHISA MIZUTA, M.D.,
OSAMU TAKEMOTO, M.D., KElJl SHIMIZU, M.D.,
and SUSUMU NAKATANI, M.D.

episode of left hemiparesis followed by dysphasia with a
precordial squeezing sensation, which lasted for several
minutes without loss of consciousness. In January and
March, prior to admission, he had experienced two other
episodes of transient weakness of the right lower extremity
with focal twitching of the left leg, which cleared up in a
few minutes. The patient’s familial and personal medical
histories were non-contributory.
Neurological examination was normal on admission. No
bruit was audible in the neck or around the orbits, Blood
pressure was 146/100 rnm Hg, while the pulse rate was 60/
min, with a regular rhythm. Chest X-rays, an electrocardiogram, and an echocardiogram were normal. The results of
the complete laboratory examination were normal, except
for mild hyperlipemia. A CT scan of the brain was normal.
A four-vessel cerebral angiographic study demonstrated atherosclerotic stenosis of the proximal A-2 portion of the left
ACA (Fig. 1).
CASE REPORT
This lesion was thought to be responsible for the isA 43-year-old right-handed businessman was admitted
chemic
episodes, since no other stenotic or occlusive lesion
to our hospital on March 8, 1985 because of a sudden
was found in any of the extracranial or intracranial cerebral
arteries. The STAs were fairly well developed on both sides.
A single-photon-emission CT scan revealed decreased cerebral blood flow in the bilateral frontal area, as well as
From the Department of Neurosurgery, Minoh City Hospital (Y.I., T.M., O.T.) mild general reduction of the blood flow in both hemiand Osaka University Medical School (K.S., S.N.), Osaka, Japan.
spheres; the latter was probably due to the diaschisis. ConAddress reprint requests to Yoshikazu Iwata, M.D., Department of Neurosur- sidering the repeated episodes of transient ischemic attack,
gery, Minoh City Hospital, 5-7-1Kayano, Minoh, Osaka 562, Japan.
the findings of cerebral angiography and the patient’s relaReceived for publication January 27, 1988.
tively young age, bypass surgery to the distal portion of the

Microsurgical cerebral revascularization procedures for
anterior and posterior circulation have been commonly performed since Donaghy and Yasargil’ reported their successful cases of superficial temporal artery (STA) to middle
cerebral artery (MCA) anastomosis in 1968. However, there
have been only a few reports of bypass operations for
stenotic or occlusive lesions of the anterior cerebral artery
(ACA). Revascularization of the deep-seated area of ACA
is usually impossible without using a graft of some kind. An
interposed cephalic vein bypass graft between the STA and
a distal branch of the ACA was reported.2 The ACAs of
both sides were anastomosed side-to-side in situ distal to the
stenotic ~ e s i o n . ~ ’ ~
This paper describes a new approach to correction of
ACA ischemia-an interposed arterial graft bypass using the
contralateral STA.

0 1988 Alan R. Liss, Inc.

Interposed STA Graft Bypass For ACA Ischemia

15

Figure 1. Oblique view of postoperative left (L) carotid angiogram,
demonstratingstenosis in the A-2 portion of the left anterior cerebral
artery (arrows).

Figure 3. a: The arterial graft was anastomosed between the frontal
branch of the right superficial temporal artery and the left internal
frontal artery. Arrows show site of anastomosis. b: On closing the
dura, a small gap for fhe graft to enter was left at its anterior margin.
A small piece of gelatin sponge (Gelfoam) around the graft. c: The
frontal bone flap was replaced and fixed. The graft was passed into
the skull via the midfrontal burr hole.

ronal skin incision was made behind the hairline, and a
bifrontal craniotomy was carried out (Fig. 2). The dura
mater
was opened along the anterior margin of the craniFigure 2. Tracingof the branches of the superficial temporal arteries
otomy.
The superior sagittal sinus was ligated and divided
on both sides in front of the transcoronal scalp incision line. The
diagram shows that the dissection of the donor superficial temporal at the anterior border in order to minimize brain retraction
artery on the left, harvesting of the contralateralsuperficial temporal during the anastomotic procedure. The left internal frontal
artery graft (between small arrows), and interposing of the anastoartery, the peripheral branch of the callosomarginal artery,
mosis between the donor artery (large arrow), the arterial graft and
the left internal frontal artery can be performed with a single scalp was exposed along the frontal interhemispheric fissure with
the aid of an operating microscope. The frontal branch of
flap.
the left STA was then isolated, and an 8-cm length was
left ACA was thought to be justified, to prevent future excised from the undersurface of the frontal skin flap for
ischemic events by restoring a normal blood flow to the area use as an arterial graft. The lumen of the graft was irrigated
with heparinized saline.
of poor perfusion.
The anterior branch of the right STA was identified and
Operative Procedure
prepared as the donor artery. After trimming of the vessel
On March 25, 1985, revascularization surgery was per- stumps, the graft was anastomosed end-toend to the distal
formed. Under satisfactory general anesthesia, a transco- end of the frontal branch of the right STA with 12 inter-

16

lwata et al.

mpt& 10-0 nylon monofilament sutures. The lumen of the
The patient was discharged in excellent condition witharterial graft in situ was again irrigated with heparinized out any complications or neurological deficits. He resumed
saline solution. The distal end of the graft was then anasto- work and has been well and free of cerebral ischemic events
mosed end-to-side, in the usual manner, to the left internal for 32 months since the surgery, without any medication.
frontal artery with 11 interrupted 11-0 monofilament nylon
sutures.
After removing Scoville’s microclips used for temporary DlSCUSSlON
occlusion of the vessels, pulsation of the graft and of the left
An international randomized trial on extracranial to ininternal frontal artery, as seen under the microscope, seemed tracranial (EC-IC) bypass failed to confirm that this procesatisfactory. Each anastomosis was completed in 35 min- dure has greater efficacy for prevention of stroke than has
Utes. The dura was closed, leaving a gap for the graft to medical the rap^.^ Although longer follow-up by repeated
enter. The bone flap was replaced, allowing the graft to pass angiography and clinical observation is necessary to conthrough the burr hole of the skull in the midfrontal area clude that this bypass surgery has been effective in prevent(Fig. 3). The scalp was sutured in two layers. No systemic ing cerebral ischemia, the patient described in this paper
anticoagulant was administered either during or after the benefited from the bypass surgery and has been free of
surgery.
ischemic events for more than 2 years.
This is the first report, to our knowledge, of an STA
Operative Result
graft bypass for the tireatment of ischemic symptoms inThe patient’s postoperative course was uneventful. No duced by a stenotic lesion of the ACA. The new method
marginal scalp ischemia was noted. Pulsation of the graft uses the contralateral STA as an arterial graft, which is
was palpable in the patient’s right forehead. Right cerebral interposed between the. distal branch of the unilateral STA
angiography performed on the 16th postoperative day also and the distal branch of the ACA. The advantage of the
proved the patency of the graft (Fig. 4). The left internal technique is that the graft harvesting and the anastomosis
frontal artery and the callosomarginal artery were filled via can be carried out with a single transcoronal scalp incision.
Microsurgical revascularization for ACA ischemia has
the bypass route. The stenotic lesion of the left ACA per se
remained unchanged. Normal cerebral blood flow on both been reported less frequently than for lesions of the MCA
hemispheres, with no focal ischemic region, was confirmed and the internal carotid artery. Since there is no suitable
by single-photon-emission CT scans performed on the 23rd scalp artery long enough to reach the deep-seated ACA,
day and 7 months after the surgery. Repeated electroenceph- revascularization of this artery can only be achieved either
alograms have been negative for paroxysmal discharges and by a side-to-side anastomosis between the A C A S or
~~
by~an
focal abnormalities.
interposed graft bypass .*

Figure 4. Left: Lateral and Right: anteroposterior view of postoperative right carotid angiogram, black arrows indicate filling of the
left internal frontal artery and the callosomarginal artery on the left

side through the bypass graft. White arrows indicate the site of
anastomosis of the graft.

Interposed STA Graft Bypass For ACA ischemia

17

For the interposing graft, synthetic tubes,c8
the anastomosis can be carried out with a single transcoronal
and free radial artery s e g m e n t ~ ' ~ 'have
' ~ been used for scalp incision.
cerebral revascularization in occlusive cerebrovascular diseases. All currently available microvascular synthetic tube
grafts, except for very short ones,6 are unsuitable for small REFERENCES
arteries involved in EC-IC bypass surgery.' Several disad- 1. Donaghy RMP, Yasargil MG: Extra-Intracranial blood flow diversion.
vantages of the vein bypass graft have been reported.""'
Proceedings of the 36th American Association of Neurological Surgeons. 1968,p. 104.
Donor-recipient size discrepancy may pose a technical dif2. Itoh Z: A new technique of intracranial anastomosis between distal
ficulty to anastomosis. Torsion, angulation, kinking, and
anterior cerebral arteries (ACA) for ACA occlusion and its indication.
easy compressibility of a thin-walled vein conduit may lead
Neurol Med Chir (Tokyo) 21:931-939,1981 (in Japanese).
to graft thrombosis. Since it is necessary to keep a high flow 3. Ishii R, Koike T, Takeuchi S, Ohsugi S, Tanaka R, Konno K: Anastomosis of the superficial temporal artery to the distal anterior cerebral
to expand the wall and maintain graft patency, a slow flow
artery with interposed cephalic vein graft: Case report. J Neurosurg
through a large-sized vein graft between small arteries makes
58:425429, 1983.
it unsuitable for a short interposed graft. Arteries are thought 4. Ikeda A, Okada T, Shibuya M, Noda S, Sugiura M, Iguchi I, Gonda
T, Kageyama N: Revascularization of the anterior cerebral artery: A
to be physiologically more suitable as graft vessels than
report of two cases. J Neurosurg 62:603-606,1985.
vein^.'^,'^ Maroon and Donaghy14 reported in their experi- 5. The EC/IC Bypass Study Group: Failure of extracranialhtracranial
arterial bypass to reduce the risk of ischemic stroke: Results of an
mental study that the patency rate with arterial grafts was
randomized trial. N Engl J Med 313:1191-1200,1985.
better than that with venous grafts. They attributed this to 6. international
Derman GH, Reichman OH: Polytetrafluoroethylene for microarterial
the greater ease of handling due to the thicker wall, the
prosthetic grafts. Arch Surg 116:211-216,1981.
reduced tendency toward redundancy and kinking, and the 7. Story JL, Brown WE Jr, Eidelberg E, Arom KV, Stewart J R Cerebral
revascularization: Proximal external carotid to distal middle cerebral
better graft-to-recipient artery ratio.
artery bypass with a synthetic tube graft. Neurosurg 3:61-65, 1978.
Radial arteries have been used for ischemic lesions of 8. Weinstein PR,Reinert RL, Brittain F: Delayed thrombosis of synthetic
microvascular bypass grafts. Neurosurg 9:268-274,1981.
the posterior circulation12 and the anterior circulation.l3
Samson DS, Hodosh RM, Clark K: Microsurgical treatment of tran9.
However, the morbidity associated with removal of the
sient cerebral ischemia: heliminary result in 50 patients. JAMA
radial artery is not negligible. If the diameter of anterior
241:376-378, 1979.
branch of the STA is large enough to maintain pateney, as 10. Spetzler RI, Rhodes RS, Roski RA, Likavec MJ: Subclavian to middle
cerebral artery saphenous vein bypass graft. J Neurosurg 53:465-469,
in this case, the contralateral STA can be used as an arterial
1980.
graft. It can be harvested easily from the same skin flap and 11. Sundt TM Jr, Piepgras DG, Houser OW,Marsh R, Fode C: Saphenous
vein bypass grafts for giant aneurysms and intracranial occlusive disis suitable as a graft for ACA revascularization. The ipsilatease. J Neurosurg 65:439-450,1986.
eral STA can be used as the donor artery.
12. Ausman JI, Nicoloff DM, Chou S: Posterior fossa revascularization:
When the major blood supply to the scalp was disconAnastomosis of vertebral artery to PICA with interposed radial artery
graft. Surg Neurol9:281-286,1978.
nected, marginal skin necrosis would be a frequent occur13. Yasui N, Ohta H, Suzuki A, Kamiyama H: Cervical carotid artery to
rence in STA-MCA anastomosis.l6 Arterial distributions in
middle cerebral artery anastomosis with interposed radial artery graft,
the frontal scalp, however, are rich through the supraorbital
in Spetzler RF, Carter LP, Selman WR, Martin NA (eds): Cerebral
Revascularization for Stroke. New York, Thieme Stratton, 1985,pp.
and zygomaticotemporal arteries, the skin necrosis associ379-385.
ated with the transcoronal incision would be a less frequent 14. Maroon JC, Donaghy RMP: Experimental cerebral revascularization
occurrence in this procedure. l7
with autogenous grafts. J Neurosurg 38:172-179,1973.
CONCLUSION

A new revascularization technique for the ischemic
events of ACA was performed. The contralateral STA was
utilized as an arterial graft between the STA and the ACA.
The advantage of this method is that graft harvesting and

15. Whang CJ, Mozingo JR, Rhoton AL Jr: Comparison of blood flow
and patency in arterial and vein grafts to basilar artery. Stroke 6:445448, 1975.
16. Reichman OH:Complications of cerebral revascularization. Clin Neurosurg 23:318-335,1976.
17. Elisevich KV, Colohan ART, Brem S, Comair Y: A rapid and modifiable technique for regional exposure in cerebral surgery: A technical
note. J Neurosurg 67:140-142,1987.