SOME ANATOMICAL AND SURGICAL RELATIONS OF 
THE PARTS INVOLVED IN THE OPERATION 
OF INTRA-CRANIAL NEURECTOMY OF 
THE FIFTH PAIR OF NERVES AND 
REMOVAL OF THE GASSERIAN 
GANGLION. 
BY 
WILLIAM J. TAYLOR, M.D., 
PROFESSOR OF ORTHOPAEDIC SURGERY IN THE PHILADELPHIA POLYCLINIC; ATTENDING SURGEON 
TO ST. AGNES' HOSPITAL ; ASSISTANT SURGEON TO THE ORTHOPAEDIC HOSPITAL 
AND INFIRMARY FOR NERVOUS DISEASES. 
REPRINTED FROM THE TRANSACTIONS 
OF THE PHILADELPHIA COUNTY MEDICAL SOCIETY, 
1894. SOME ANATOMICAL AND SURGICAL RELATIONS OF 
THE PARTS INVOLVED IN THE OPERATION 
OF INTRA-CRANIAL NEURECTOMY OF 
THE FIFTH PAIR OF NERVES AND 
REMOVAL OF THE GASSERIAN 
GANGLION. 
By WILLIAM J? TAYLOR, M.D., 
PROFESSOR OF ORTHOPEDIC SURGERY IN THE PHILADELPHIA POLYCLINIC; ATTENDING SURGEON 
TO ST. AGNES' HOSPITAL ; ASSISTANT SURGEON TO THE ORTHOPEDIC HOSPITAL 
AND INFIRMARY FOR NERVOUS DISEASES. 
[Read February 14, 1894.] 
Intra-cranial neurectomy of the fifth nerve and the removal 
or destruction of the Gasserian ganglion must now be given its place 
as one of the most beneficial as well as one of the most brilliant and 
difficult operations in surgery. 
Rose and Hartley have given us very definite directions as to the 
mode of opening the skull and general surgical technique, but I have 
failed to find an exact statement by anyone of the relative positions 
of the foramina, the ganglion, and arteries. It is with the hope of 
adding to our knowledge of these anatomical and surgical relations 
that, at the suggestion of Dr. W. W. Keen, I have lately made a 
careful study of the interior of twenty skulls taken in the most 
part from the collection in the Mutter Museum of the College of 
Physicians. My aim has been to establish by accurate measurements 
the distance between the foramina of exit of the second and third 
branches and to establish definitely their relationship with the for- 
amen spinosum, the carotid canal, and the depression or fossa for 
the ganglion. As is well known, this ganglion, a reddish-gray band 
of ganglionic matter slightly curved in its long axis so as to pre- 
sent a convexity forward and outward, rests upon a depression 
in the petrous portion of the temporal bone. From the convex 
antero-external border, three large bundles of nerve fibres arise. 2 
TAYLOR, 
The^rs^ or ophthalmic division is the smallest and is purely sensory 
in function. It arises from the upper portion of the ganglion, enters 
the cavernous sinus, and passes forward in contact with the outer 
wall of the cavernous sinus, through the sphenoidal fissure into the 
orbit. 
The second or superior maxillary division, also a sensory nerve, 
passes out through the foramen rotundum and enters the orbit 
through the spheno-maxillary fissure. 
The third or inferior maxillary, the largest of the three divisions, 
consists of two portions : the larger or sensory root arising from the 
inferior angle of the ganglion, and the smaller or motor root passes 
beneath the ganglion. This latter accompanies the sensory root and 
joins it after it emerges from the foramen ovale. 
A small branch, the recurrent, passes into the cranium through 
the foramen spinosum along with the middle meningeal artery. 
This divides into two small branches to be distributed to the dura 
mater and to the lining membrane of the mastoid cells. 
As will be seen by this short account of the three divisions of the 
fifth nerve, it is impossible to make a definite section of the first 
division without doing great damage to the cavernous sinus, the third, 
fourth, and sixth nerves, and the carotid artery. 
We must be contented to cut the attachments and remove or 
destroy the ganglion, and with it the second and third divisions as 
they pass through the foramen rotundum and foramen ovale. 
The middle meningeal artery as it enters the cranium through the 
foramen spinosum must frequently be wounded or torn through in 
our endeavors to reach the ganglion. For this reason it is often 
wiser to ligate and deliberately cut it than to run the risk of tearing 
it as it passes through the foramen ; when by any chance this occurs 
our only means of controlling the hemorrhage is by packing the 
foramen or the ligation of the external carotid artery below the 
origin of the internal maxillary artery. 
In this examination, for convenience and because it is a measure 
with which we are all familiar, I have taken the inch and its sub- 
divisions of sixteenths as the most readily understood and easiest 
obtained unit of comparison. 
First. I have measured the distance, centre to centre, from the 
foramen spinosum to the foramen ovale; from the foramen ovale to 
the foramen rotundum, and from the foramen spinosum to the fora- 
men rotundum. 1NTKA-C R ANIAL NEURECTOMY OF FIFTH PAIR. 
3 
Second. I have measured, centre to centre, the distance by which 
the foramen ovale is in front of the foramen spinosum, taking the 
sides of an imaginary parallelogram, the foramen spinosum being the 
external and posterior, and the foramen rotunduni the anterior and 
internal points. 
Also, the distance by which the foramen ovale is internal to the 
foramen spinosum, the distance by which the foramen rotundum is 
anterior to the foramen spinosum, and the distance by which the 
foramen rotundum is internal to the foramen spinosum. 
Third. The diameters of the three foramina-spinosum, ovale, 
and rotundum. 
Fourth. The distance between the centre of the foramen rotundum 
and the depression or fossa for the ganglion, and from the centre of 
the foramen ovale to this fossa for the ganglion. 
Fifth. The width of the bridge of bone between the foramen 
ovale and the carotid canal. 
Fig. 1. 
A, Spinosum to ovale. B, Ovale to rotundum. C, Spinosum to rotundum. D, Ovale anterior 
to spinosum. E, Ovale internal to spinosum. F, Rotundum anterior to spinosum. G, Rotun- 
dum internal to spinosum. H, Rotundum to ganglion. I, Ovale to ganglion. J, Bridge of 
bone between foramen ovale and carotid canal. 
In going over these skulls carefully I have found such a great 
inequality in the measurements between the two sides that I have 
made a definite note of these variations, and give in my table the 
greatest, the least, and the mean measurements. Possibly a better 
understanding of the system of measurements may be gained by a 
glance at Fig. 1, which shows the relative positions of foramina, etc. 
I have also had made a series of twelve photographs, and of these 
have selected four of the most typical. In these the inequality is 
seen most distinctly. 4 
TAYLOR, 
Fig. 2. 
Fig. 3. 
The distance between the centre of the foramen spinosum and the 
centre of the foramen ovale varies from 2 to 9, with a mean distance 
of about sixteenths of an inch. 
Fig. 4. 
The centre of the foramen ovale to the centre of the foramen 
rotundum varies from 6 to 13, with an average of between 9^ and 
lO^ sixteenths of an inch. 
The centre of the foramen spinosum to the centre of the foramen INTRA-CR ANIAL NEURECTOMY OF FIFTH PAIR. 
5 
rotundum varies from 8 to 17, with an average of between 13^ and 
14^ sixteenths of an inch. 
The centre of the foramen ovale is anterior to the centre of the 
foramen spinosum from 2 to 6, with an average of from 3-^ to 3^- 
sixteenths of an inch. 
The centre of the foramen ovale is internal to the centre of the 
foramen spinosum from 2 to 6, with an average of from 3^ to 3^ 
sixteenths of an inch. 
The centre of the foramen rotundum is anterior to the centre of 
the foramen spinosum from 9 to 14, with an average of from 11^ 
to 12 sixteenths of an inch. 
The centre of the foramen rotundum is internal to the centre of 
the foramen spinosum from 4 to 11, with an average of from 
7^ to 8^ sixteenths of an inch. 
The distance from the centre of the foramen rotundum to the 
centre of the fossa for the Gasserian ganglion varies from 8 to 16, 
with an average distance of between 13 and 13^% sixteenths of an 
inch. 
The centre of the foramen ovale is distant from the centre of the 
fossa or groove for the ganglion from 2 to 9, with an average distance 
of sixteenths of an inch. 
The width of the bridge of bone between the foramen ovale and 
the carotid canal varies from 1 to 9, with an average width of from 
4^| to 5^ sixteenths of an inch. 
The diameters of the foramina have been determined to be as 
follows : 
The spinosum varies from less than 1 to 3, with an average of 
from 1^ to 1^ sixteenths of an inch. 
The ovale varies from 3 to 6, with an average of 4|£ sixteenths of 
an inch. 
The rotundum varies from 1 to 3, with an average of between 2^ 
and 22%- sixteenths of an inch in diameter. 
It will be seen by these measurements, and by a glance at the 
accompanying photographs and table, that the relationship between 
these different points is by no means constant, and in operating we 
must realize the fact. In the majority of instances the foramen spi- 
nosum with the middle meningeal artery is far enough away from the 
foramen ovale and the third branch of the nerve, to enable us suc- 
cessfully to cut the latter without wounding the bloodvessel. This 
is particularly marked in Fig. 4, on the left side, where the distance 
is yg- of an inch. On the other hand, the spinosum may be so 6 
INTRA -CRANIAL NEURECTOMY OF FIFTH PAIR. 
nearly in a line with the ovale that to reach it without wounding 
the middle meningeal artery would be impossible. In some of the 
reported cases of the operation, where mention is made of alarming 
hemorrhage, I am convinced this state of affairs existed. 
For this reason, whenever the exposure of the third branch of the 
nerve is at all difficult, the surgeon should at once search for, 
ligature the artery, and cut it across, before attempting to find the 
nerve. This ligation of the artery is not very difficult, and will at 
once give much greater freedom of action. 
The size and shape of the foramina vary in the different skulls; 
especially is this so with the ovale, which is at times perfectly 
round. 
The rotundum is most constant in its shape and its variations are 
of little importance to the surgeon. 
The spinosum varies much, and in one instance (Fig. 3), as is well 
shown in the photograph, there are two distinct foramina on the left 
side. 
The character and sex of the skull seem to have little bearing 
upon the relative position of the foramina, with the exception that a 
broad, flat skull usually shows a greater distance between them, and 
it has been impossible to fix upon any rule by which these variations 
may be anticipated. 
Average Measurement of Twenty Skulls, Right and Left Sides. 
Centre to centre. 
Centre to centre. 
Diameter. 
Sp. to ov. M 
2 
PS 
o 
O 
3 
i 
a. 
02 
Ov. ant. to 
spin. * 
Ov. int. to 
spin. 01 
R. ant. to spin. 
R. int. to 
spin. 
8 
a 
Oval. 50 
10 
I 
Rot. to gang. £ 
12 
tub 
H 
to 
O 
Ov. to carotid 
canal, width g 
bridge of bone 
Average 
20 skulls. 
Right, 
4'5/20 
lO'/ao 
1412/20 
31/50 
12.00 
7>3/20 
l12/20 
4'% 
22/20 
130/20 
5'2/20 
5'/2o 
Left, 
4"/2o 
9°/20 
37/2o 
39/2o 
ll10/20 
8"/2o 
4'0/20 
2'/20 
13.00 
5'2/20 
4'3/2o 
Smallest 
20 skulls. 
Right, 
2 
8 
12 
2 
2 
9 
4 
1 
4 
1 
10 
2 
1 
Left, 
2 
6 
8 
2 
2 
9 
4 
1- 
3 
1 
8 
2 
1 
Largest 
20 skulls. 
Right, 
7 
13 
17 
6 
5 
13 
11 
2 + 
6 
3 
16 
9 
9 
Left, 
9 
11 
17 
6 
6 
14 
10 
3 
6 
3 
16 
8 
8