Acta Neurochir (Wien) (1992): 114:135 - I38 :Acta . Neurochlrurgica �9 Springer-Verlag 1992 Printed in Austria

Experience with the Infratentorial Supracerebellar Approach in Lesions of the Quadrigeminal Region, Posterior Third Ventricle, Culmen Cerebelli, and Cerebellar Peduncle

G. Laborde 1, J. M. Gilsbach 1, A. Harders 1, and W. Seeger 2

Neurosurgical Department, Technical University of Aachen, and 2 Department of General Neurosurgery, University of Freiburg, Federal Republic of Germany

Summary

We report about our experience with the infratentorial supra- cerebellar approach in 23 patients operated on for lesions located in the posterior part of the third ventricle, quadrigeminal plate, culmen cerebelli and cerebellar peduncle.

Three patients had transient worsening of their deficits imme- diately after surgery. Three patients developed haemorrhages post- operatively requiring surgical evacuation. One of them died.

None of the patients developed specific complications which could without any doubt be attributed to the approach. We con- cluded that in combination with intra-operative CSF drainage and the sitting position the infratentorial supracerebellar approach allows safe access to lesions situated in an area limited by the posterior part of the third ventricle, the fastigium level and both cerebellar pedun- cles.

Keywords: Infratentorial supracerebellar approach; quadrige- minal region; pineal tumour; third ventricle tumour.

Introduction

H o r s l e y 6 in 1910 and K r a u s e 9 in 1926 were the first

to desc r ibe the s u p r a c e r e b e l l a r i n f r a t e n t o r i a l a p p r o a c h

for q u a d r i g e m i n a l les ions. O t h e r rou t e s to the r e g i o n

o f the q u a d r i g e m i n a l p la te i nc lude the t r ansca l lo sa l

a p p r o a c h 1, the t r a n s v e n t r i c u l a r a p p r o a c h 26, a n d the

occipital transtentorial approach 4' 7, 10, 11, 15, 20, 24

U l t i m a t e l y , the q u e s t i o n o f w h i c h a p p r o a c h is u sed

d e p e n d s on the l o c a l i z a t i o n a n d ex ten t o f the t u m o u r

a n d the i n d i v i d u a l cho ice o f the su rgeon . W e use the

s u p r a c e r e b e l l a r - i n f r a t e n t o r i a l a p p r o a c h to r e a c h tu-

m o u r s in the t e c tum, in the p o s t e r i o r p a r t o f the 3rd

vent r ic le , in the do r sa l a n d d o r s o l a t e r a l m i d b r a i n , in

the p inea l reg ion , a n d in the c u l m e n cerebel l i .

T h e p u r p o s e o f this r e t r o spec t i ve s tudy was to de-

t e rmine w h i c h c o m p l i c a t i o n s can be a t t r i b u t e d to the

s u p r a c e r e b e l l a r - i n f r a t e n t o r i a l a p p r o a c h i tse l f and to

def ine its l imits .

Patients and Methods

From 1979 to 1990, we operated on a total of 23 patients using the supracerebellar infratentorial approach. The patients were 9 to 72 years of age (mean 36 years). Thirteen were females and nine males.

Pre-operative stereotactic biopsy had been performed on eight patients, since operability could not be conclusively determined by CT and MRI. In the remaining 15 patients, surgery was performed under the assumption of a technically operable benign lesion. One patient had undergone pre-operative radiotherapy without confir- mation of the histology by biopsy. The most frequent pre-operative symptoms included signs of raised intracranial pressure (n-10), ataxia (n = 4), and Parinaud syndrome (n = 3) in one patient with a pineal germinoma and in two patients with epidermoids.

Eleven of the patients had had obstructive hydrocephalus prior to surgery. In 10 of these patients a ventriculo-atrial shunt was performed and in one case the tumour was directly approached.

Computer tomography and angiography were performed pre- operatively in all cases; in five cases an MRI examination was carried out.

The majority of tumours were located in the culmen cerebelli, followed by lesions in the tectum and the pineal region (Table 1).

The patients were operated on in the sitting position. The head was secured in a Mayfield skull clamp in AP position and bent forward so that the direction of the straight sinus was parallel with the horizontal plane (Fig. 1). Depending on the side of the lesion we performed a unilateral or a midline osteoplastic suboccipital/occip- ital trepanation preceeded by a longitudinal incision.The upper botmdary was about 1 cm above the transverse sinus, the lower one about 2-3 cm below it. The dura was opened close to the lower border of the sinus to prevent protrusion of the cerebellum (Fig. 1).

The upper edge of the incision was secured with stay sutures. We always tried to reduce intracranial pressure by release of CSF

in order to facilitate the procedure above the culmen cerebelli or the quadrangular lobe. If no hydrocephalus was present, a lumbar drain-

136 G. Laborde et al.: Experience with the Infratentorial Supracerebellar Approach in Lesions

Table I. Location, Histology and Complications

Location Pathology Complications (No)

culmen cerebelli 2 astrocytoma (I, III) infection (1) 1 haemangiopericytoma 1 medulloblastoma 1 metastasis 1 AVM infection

quadrigeminal region 3 AVM haemorrhage *(2) hydrocephalus (1)

pineal region

1 haemangioblastoma 1 metastasis 1 falcotentorial meningioma 1 ependymoma 0II) 1 epidermoid

midbrain

IIIrd. ventricle

2 germinoma (IV) 1 pineocytoma (I) 1 dysplasic cyst

2 cavernoma 1 metastasis

2 teratoma

haemorrhage (1)

* Lethal.

~ ~

Fig. 1. Intra-operatively the patient's head is positioned in such a way that the straight sinus is in a horizontal plane. Positioning and location of the unilateral trepanation are schematically shown

age was inserted immediately before surgery or the cisterna magna was punctured intra-operatively after trepanation. In patients with an already existing shunt the valve was pumped or CSF aspirated from the Rickham reservoir.

No ventricular drainage was performed intra-operativelf ~ 19, 20.

Results

The diagnoses and histological findings are listed in

Table 1. With mild positive end-expiratory pressure, haemostasis during jugular vein compression and pre- cordial Doppler , no clinically significant air embolism

was observed. In three patients the occipital sinus had

to be severed, in 12 patients bridging veins between

vermis and tentor ium or between quadrangular lobe and tentor ium were severed.

In two patients pre-existing neurological deficits

were more p ronounced post-operat ively than before

operation. One of these patients had a te ra toma in the

3rd ventricle and the second patient a medul loblas toma in the culmen cerebelli. These two patients had an in- creased ataxia.

One patient with a dysplastic cyst developed post-

operatively new but transient bilateral internuclear eye movement disturbances worsened in prone position,

associated with a severe intracranial hypotens ion syn- drom, latent hemiparesis, ataxia and reduced short time memory capacity.

Three other patients suffered post-operat ive haem- orrhage. One of them had an epidural haema toma in

G. Laborde et al.. Experience with the Infratentorial Supracerebellar Approach in Lesions 137

the area of trepanation and two patients had haemor- rhages in the operated area with intraventricular ex- tension which had to be evacuated surgically. In one of these patients the haemorrhage followed an oper- ation for a cavernoma of the pons and midbrain. One patient with an arterio-venous angioma in the area of the quadrigeminal plate died of haemorrhage 5 hours after surgical removal of the same.

One patient developed obstructive hydrocephalus post-operatively, which was caused by local swelling and had to be treated with a ventriculo-atrial shunt. Three patients had a wound infection which required wound revision with removal of the bone flap.

Discussion

The infratentorial supracerebellar approach pro- vides access to an area ranging from the transverse fissure to the fastigium level, laterally to the border of the quadrigeminal plate and to the midline portion of the upper cerebellar peduncle and posterior portion of the 3rd ventricle 4' 13, 22. This approach is not suited for lesions located either in the brachium conjunctivum or in the 4th ventricle below the fastigium level or for those which spread extraventricularly into the thala- 15qUS.

We made no exceptions in requesting pre-operative angiography as we felt it necessary in every case to become familiar with the topography of the veins in the vicinity of the tumour and to be able to rule out any vessel malformation.

The intracranial decompression achieved by the use of a pre-operative shunt facilitated the downward re- clination of the cerebellum, however, it was associated with a considerable risk (18.5%) of infection 3. In com- parison Rappaport and Shalit ~6 had a 10% infection rate when using peri-operative external ventricular drainage in obstructive hydrocephalus caused by in- fratentorial tumours. It seems preferable to use that method for treating the hydrocephalus, at least in pa- tients with an assured postoperative normalization of the CSF pathways and absorption.

Only in one patient was a shunt necessary in the postoperative phase due to swelling of the midbrain and the development of an obstructive hydrocephalus.

We preferred the sitting position for the operation because of the associated low intravenous pressure and the downward shift of the cerebellum after release of CSF. Thereby good intra-operative vision without us- ing retractors is provided for and less venous bleeding occurs. The supine position, as recommended by

Kobayashi 8, can cause an increase in intracranial pres- sure and can hence bring about complications. We are not in favour of the park bench position 24 because it can obstruct the surgeon's movements. Careful occlu- sion of all the opened veins prevented the occurrence of symptomatic air embolism, a complication which induced Kobayashi 8 to use the same approach in pa- tients in the supine position. In cases where it does occur, it can be detected by Doppler sonography and treated before a clinically relevant amount of air has entered.

We performed a midline or unilateral osteoplastic suboccipital/occipital trepanation. The site of the dura opening was selected according to the localization of the tumour. Both the approach above the quadrangular lobe or the culmen cerebelli proved to be suitable for reaching the quadrigeminal region. For lesions in the fastigium or on the midline below the culmen level we preferred the lateral approach.

In three patients the occipital sinus and in twelve patients bridging veins had to be occluded and severed. None of these measures resulted in any deficits 13.

Strict adherence to the indication for this approach eliminates the necessity for incising the tentorium, since in our patients the tentorium fold was large enough for the resection of the tumour even above the tentorial edge 18. In no case did Galen's vein, Rosenthal's veins nor the internal cerebral veins present an obstacle. We attribute this to the strict indication for this approach.

In no case did complications occur which could unequivocally be attributed to this particular approach.

The postoperative increase in deficits in three pa- tients must be attributed to the local manipulation in the vicinity of the brainstem and not to lesions caused by the approach. All surviving patients recovered com- pletely with exception of one patient with a dysplastic cyst who still has reduced short time memory capacity.

The aetiology of the eye movement disturbances she developed is unknown. Heimburger 5 reported a similar case of a patient presenting oculogyric crises occurring when operated upon in the strictly supine position who had a tumour located in the posterior third ventricle.

The 5% morbidity rate and the 2.5% mortality rate are in accordance with the rates and causes given in the literature 8' 12, 13, 14, 17, 21, 23 ranging from 0 to 30%

for mortality without morbidity. They are not related to the approach. Using the supracerebellar infraten- torial approach the cerebral structures are not damaged compared with the transcallosal 1 or the transventri- cular approach 26. Nor is there any danger of harming

138 G. Laborde et al.: Experience with the Infratentorial Supracerebellar Approach in Lesions

the occipital lobe as can occur with the transtentorial route. This approach should be used in lesions located mainly laterally and rostrally. The occipital-transten- torial approach is' 24 is not as well suited for access to

lesions located inferior to the aqueduct level, since it requires dissection past Galen's vein.

References

1. Dandy WE (1921) An operation for the removal of pineal tu- mours. Surg Gynecol Obstet 33-2:113-119

2. Fahlbusch R, Strauss C, Huk W, Rockelein G, Kompf D, Ru- precht KW (1990) Surgical removal of pontomesencephalic cav- ernous hemangiomas. Neurosurgery 26:449-56

3. Gilsbach J, Zentner J (1988) Differentialtherapie des Hydro- cephalus bei Raumforderungen der hinteren Schgdelgrube. In: Hase U, Reulen HJ (Hrsg) Die akute Raumforderung in der hinteren Schfidelgrube. Ueberreuter Wiss, Wien, pp 77-85

4. Glasauer FE (1970) An operative approach to pineal tumours. Acta Neurochir (Wien) 22:177-180

5. Heimburger RF (1988) Positional oculogyric crises. Case report. J Neurosurg 69:951453

6. Horsley V (1910) Discussion. Proc R Soc Med 3:2 7. Jamieson KG (1971) Excision of pineal tumours. J Neurosurg

35:550-553 8. Kobayashi S, Sugita K, Tanaka Y, Kyoshima K (1983) Infra-

tentorial approach to the pineal region in the prone position. J Neurosurg 58:141-143

9. Krause F (1926) Operative Freilegung der Vierhiigel, nebst Beob- achtungen fiber Hirndruck und Dekompression (mit Lichtbil- dern). Zentralbl Chir 53:2812-2819

10. Lapras C, Patet JD, Mottolese C, Lapras C Jr (1987) Direct surgery for pineal tumours: occipital-transtentorial approach. Progr Exp Tumour Res 30:268-280

11. LazarML, Clark K (1974) Direct surgicalmanagement ofmasses in the region of the vein of Galen. Surg Neurol 2:17-22

12. Obrador S, Soto M, Gutierrez-Diaz JA (1976) Surgical man- agement of tumours of the pineal region. Acta Neurochir (Wien) 34:159-171

13. Page LK (1977) The infratentorial-supracerebellar exposure of tumours in the pineal area. Neurosurgery 1:36-40

14. Pendl G, Vorkapic P (1988) Microsurgery of midbrain lesions. Acta Neurochir (Wien) [Suppl] 42:130-136

15. Poppen JL (1966) The right occipital approach to a pinealoma. J Neurosurg 25:706-710

16. Rappaport ZH, Shalit MN (1989) Perioperative external ven- tricular drainage in obstructive hydrocephalus secondary to in- fratentorial brain tumours. Acta Neurochir 0Vien) 96:118-121

17. Reid WS, Clark WK (1978) Comparison of the infratentorial and transtentorial approaches of the pineal region. Neurosur- gery 3:1-8

18. Rhoton AL, Peace DA (1981) Microsurgery of the third ven- tricle: Part 1. Microsurgical anatomy. Neurosurgery 8:334-356

19. Rhoton AL, Yamamoto I, Peace DA (1981) Microsurgery of the third ventricle: Part 2. Operative approaches. Neurosurgery 8:357-373

20. Sano K (1976) Diagnosis and treatment of tumours in the pineal region. Acta Neurochir (Wien) 34:153-157

21. Sch/ifer M, Lapras C, Ruf H (1979) Experience with the direct surgical approach in 52 tumours of the pineal region. Adv Neu- rosurg 7:97-103

22. Seeger W (1985) Differential approaches in microsurgery of the brain. Springer, Wien New York, pp 179-183

23. Stein BM (1971) The infratentorial supracerebellar approach to pineal lesions. J Neurosurg 35:197-202

24. Stone JL, Cybulsky GR, Crowell RM, Moody RA (1990) The lateral position-dependant occipital approach to pineal and me- dial occipito-parietal lesions. Technical note. Acta Neurochir (Wien) 102:133-136

25. Suzuki J, Iwabuchi T (1965) Surgical removal of pineal tumours (pinealomas and teratomas). J Neurosurg 23:565-571

26. Van Wangenen WP (1931) A surgical approach for the removal of certain pineal tumours. Report of a Case. Surg Gynecol Obstet 53:216-220

Correspondence and Reprints: Dr. G. Laborde, Neurosurgical Department, Technical University of Aachen, PauwelsstraBe, D-W 5100 Aachen, Federal Republic of Germany.