:Acta
Acta Neurochir (Wien) (1992) 119:171-173
Ndiirochirurgica 9 Springer-Verlag 1992 Printed in Austria
Direct Skull Marking for a Pre-Operative Localization in Regional Cerebral Surgery Technical Note T. Hasegawa, K. Yamano, T. Miyamori, and H. Minamide Department of Neurosurgery, Toyama Municipal Hospital, Toyama, Japan
Nummary A method is described in which an open neurosurgical target is pre-operatively marked on the skull of a patient. A target point of the scalp surface localized fi'om neuroimaging studies is transferred onto the skull by an injection of pyoktanin blue. Its accuracy and reliability is far superior than that of the usual scalp marking. The method is simple, practical, and allows a smaller, regional craniotomy with the advantage of minimum operative invasiveness. Keywords: Pre-operative localization; marking method; scalp skull; craniotomy.
Introduction Some cerebral surgery with a superficial or subcortical operative target m a y be achieved t h r o u g h a regional craniotomy. Such a small c r a n i o t o m y utilizing a linear scalp incision is clearly desirable with the advantages of less trauma, less bleeding, less time for opening and closure, and g o o d cosmetic result 3' 5. F o r this practice, the key is an accurate placement o f the skull opening. Various methods o f pre-operative localization have been described in order to p e r f o r m it simply and inexpensively 1' z, 44, 9, 10, 12. A l m o s t all o f them transfer t u m o u r locations f r o m neuro-images onto the scalp. Even when the m o s t accurate localization is done on the scalp, however, missing the target can occur within a few centimeters. The m a j o r cause o f the incorrect trajectory is m o v e m e n t o f the scalp on the skull. We p r o p o s e here a simple m e t h o d o f direct skull marking, an injection spot, to overcome this problem.
nance imaging (MRI), or angiographic studies, usually with a surface m a r k e r 2' 6, 11. After induction o f general anaesthesia in the supine position, a 26-gauge needle is inserted from the scalp target point in a direction parallel to the C T / M R I slice or the X-rays o f the angiogram referenced, until contact with the skull is felt. Then 0.05 ml o f p y o k t a n i n blue is slowly injected by a tuberculin syringe. Thereafter, the patient is placed in a proper surgical position and a pin-fixed head holder is applied. The scalp incision used is linear, 5.0 to 8.0 cm in length. O n opening it, the m a r k i n g spot o f the target can clearly be defined on the periosteum and skull. A small r o u n d craniotomy, 2.0 to 3.5 c m in diameter, is created centered on the target with a single burr hole. Taking the neuro-imaging plane into consideration again, one can direct a chosen trajectory even to a desired subcortical target invisible on the cortical surface.
Illustrative Cases Case 1. A 44-year-old female with an unruptured aneurysm at the cortical portion of the left angular artery underwent surgery for clipping of the neck. From the angiogram, the aneurysm measuring 4 x 3 mm was transferred as a target onto the scalp mounted with grids of a soft solder (Fig. 1), and subsequently onto the skull by our method. A 6.5 cm linear skin incision and a round craniotomy with a diameter of 3.2cm were made. After opening the dura, the aneurysm was not visible on the cortical surface. On dissecting the sulcus, the aneurysm was disclosed just in the center of the craniotomy. The clipping of the neck was performed successfully. (Fig. 2).
Technique A target location is determined in advance on the scalp by c o m p u t e d t o m o g r a p h y (CT), magnetic reso-
Case 2. A 52-year-old man with an occlusion of the left internal carotid artery underwent an superficial temporal artery (STA) - middle cerebral artery (MCA) anastomosis for improvement
172
T. Hasegawa etal.: Direct Skull Marking for a Pre-Operative Localization in Regional Cerebral Surgery
Fig. 1. Case 1. Left carotid angiogram, lateral view, with localization grids of a soft solder mounting on the scalp surface. A saccular aneurysm of the angular artery is located somewhat postero-superior to the center of the grid 3-6 (arrow)
Fig. 3. Case 2. Post-operative left carotid angiogram, lateral view, showing the anastomotic vessels covering the entire territory of the middle cerebral artery and the small craniotomy, 2.3 cm in diameter
incision was made over the STA. A round craniotomy with a 2.3 cm diameter was performed. The intended target appeared in its center. The anastomosis was achieved with a satisfactory result (Fig. 3.)
Discussion
Fig. 2. Case I. Post-operative left carotid angiogram, lateral view, demonstrating the successful clipping and the craniotomy fashioned by this method. The clip is located in the center of the craniotomy with a 3.2cm of diameter
of focal mal-perfusion of the left MCA territory. The right carotid angiogram obscurely showed that area by cross circulation. A point where the left temporo-occipital artery just emerged from the Sylvian fissure was transposed onto the skull as a target. A 7 cm linear skin
A l t h o u g h CT- and M R I - g u i d e d open surgery with the stereotactic apparatus certainly offers a precise trajectory~, 4, 9, the entire procedure is rather cumbersome and time-consuming. O n the other hand, a number o f simple, inexpensive m e t h o d s for CT-guided localization on the scalp have been described 2' s, 6, to, 12 They have m a d e a small c r a n i o t o m y beneficial in conjunction with microsurgical technique and a pin-fixed head holder such as the Mayfield or the Sugita type. Then the m a j o r weak point is m o v e m e n t o f the skin, as Wester etal. have stressed 12. It is particularly enhanced when using the pin-fixed head holder. O u r m e t h o d o f direct skull m a r k i n g is very simple and quick in practice, but overcomes this problem to provide a reliable localization for an accurate trajectory. Percutaneous pre-operative localizing methods have variously been p r o p o s e d in m a m m a r y or spinal surgical fields 7, 8, t 1, Some o f them consist in inserting a needle or a wire, and others are based on an injection o f dye. The latter has a potential p r o b l e m o f diffusion7; however, in our procedure never did 0.05 ml o f p y o k t a n i n blue injected cause troublesome diffusion because the skull was nonabsorptive and the w o u n d was opened within 30 minutes after injection. Both the stereotactic craniotomies and the scalp m a r k i n g methods so far reported have applied mostly
T. Hasegawa et al.: Direct Skull Marking for a Pre-Operative Localization in Regional Cerebral Surgery in small b r a i n t u m o u r s using C T or M R I scans 1-s' 9 O u r skull m a r k i n g m e t h o d proved useful for vascular targets using a n g i o g r a m s as well. A t least a few millimeters leeway can be accepted as a target size at the cerebral convexity as seen in the illustrative cases. It m a y be emphasized that this size is far smaller t h a n a few centimeters described in former reports 3' 4, 9, 12 W e have used this m e t h o d for the past 5 years in 40 cases, i n c l u d i n g 31 neoplastic a n d 9 vascular targets, with successful results.
References 1. Apuzzo ML,I, Chandrasoma PT, Breeze RE, Cohen DM, Luxton G, Mazumder A (1988) Applications of image-directed stereotactic surgery in the management of intracranial neoplasms. In: Heilbrun MP (ed) Stereotactic neurosurgery. Concepts in neurosurgery, Vol 2. Williams and Wilkins, Baltimore, pp73132 2. Constantini S, Pomeranz S, Gomori JM (1987) CT localization of brain tumor. (Letter to the editor.) J Neurosurg 67:787-788 3. Elisevich KV, Colohan AT, Brem S, Comair Y (1987) A rapid and modifiable technique for regional exposure in cerebral surgery. Technical note. J Neurosurg 67:140-142 4. Hariz MI, Fodstad H (1987) Stereotactic localization of small subcortical brain tumors for open surgery. Surg Neuro128: 345350
173
5. Hirschberg H (1989) Localization of brain tumors with a simple scalp mounted fiducial device. Technical note. J Neurosurg 70: 280-281 6. Lee SH, Villafana T, Lapayowker MS (1978) CT intracranial localization with a new marker system.Neuroradiology 16: :570571 7. Lesoin F, Hermant .IF, Pruvo ,IP, Jomin M, Rogeau P (1986) Preoperative spinal localization using the hook wire technique. Surg Neurol 25:510-511 8. Meyer JE, Kopans DP, Stomper PC, Lindfors KK (1984) Occult breast abnormalities: percutaneous preoperative needle localization. Radiology 150:335-337 9. Moore MR, Black PM, Ellenbogen R, Gall CM, Eldredge E (1989) Stereotactic craniotomy: methods and results using the Brown-Roberts-Wellsstereotactic frame. Neurosurgery 25: 572578 10. Patil AA, Woolsey RE (1986) Scalp marking of intracranial lesions using computed tomography (CT) images. A technical note. Acta Neuroehir (Wien) 80:62-64 11. Simon N, Lesnick GJ, Lerer WN, Bachman AL (1972) Roentgenographic localization of small lesions of the breast by the spot method. Surg Gynecol Obstet 134:572-574 12. Wester K, Sortland O, Hauglie-Hansen E (1981) A simple and inexpensivemethod for CT-guided stereotaxy. Neuroradiology 20:255-256 Correspondence and Reprints: Takeshi Hasegawa, M.D., Department of Neurosurgery, Toyama Municipal Hospital, 292 Imaizumi, Toyama 939, Japan.