THE TECHNIQUE OF THE MASTOID OPERATION. 
"Y 
„.. . .. . .......... .. 
EDWARD B. DENCH, M.D., 
Professor of Otology, Bellevue Hospital Medical College ; Consulting Otologist to St. 
Luke's Hospital; Attending Aural Surgeon, N. Y. Eye and Ear Infirmary ; Fellow of 
the American Otological Society, of the N. Y. Otological Society, etc. 
Reprinted from the N. Y. Eye and Ear Infirmary Reports, Jan., 1898. THE TECHNIQUE OF THE MASTOID OPERATION. 
EDWARD B. DENCH, M.D. 
CO many monographs have appeared recently on operative 
procedures upon the mastoid process that the author 
feels that an apology is necessary for writing in detail upon 
this subject. I had supposed that in my recent work on Dis- 
eases of the Ear this topic had been treated sufficiently at 
length. A short time ago, however, an otologist of some re- 
pute was asked by a student where he could find a complete 
description of the technique of the mastoid operation. The 
reply was, that " the procedure was not described in any Eng- 
lish work excepting that of Dr. Dench," and that even in this 
book the account was exceedingly meagre. It is to correct 
this fault, therefore, that I take the liberty of writing upon this 
subject. 
Preparation of the Field of Operation.-No operation should 
be performed upon the mastoid process excepting under full 
aseptic precautions. The field of operation should be steril- 
ized in the most careful manner. My own practice is to have 
the head shaved over an area of three inches from the centre 
of the meatus. The parts are then thoroughly scrubbed with 
soap and water, then washed with ether, and then with a solution 
of bichloride of mercury, 1:1000. Previous to the shaving, 
the ear is syringed with a solution of bichloride of mercury, 
1:3000. and the canal is tamponed with a strip of iodoform 
gauze. After the entire field of operation has been cleansed, 
it is covered with a moist bichloride dressing, which is not re- 
moved until general anaesthesia is complete. All instruments 
used in the operation are sterilized by boiling. After anaes- 
Reprinted from the N. Y. Eye and Ear Infirmary Reports, Jan., 1898. 2 
TECHNIQUE OF THE MASTOID OPERATION. 
thesia is complete, the protective dressing is removed and the 
head is covered with a towel, moistened in a solution of bichlo- 
ride of mercury, 1:1000, the field of operation alone being 
exposed. The surrounding region is protected in a similar 
manner. 
The primary incision should be made from below upward, 
and should extend from just below the tip of the mastoid 
process to a point just above the attachment of the auricle. 
The incision should follow the line of auricular attachment, 
and should lie about an eighth of an inch behind this. If the 
incision is made farther backward, the anterior flap becomes 
greatly swollen, and a perfect exposure of the field of opera- 
tion is difficult. This thickening of the anterior flap not in- 
frequently leads to considerable displacement of the auricle, 
which may persist for many months. If the incision is made 
close to the line of auricular attachment, no deformity follows 
the operation. The primary incision should be carried through 
the periosteum, the soft parts being divided by a clean even 
sweep of the knife. There is seldom sufficient hemorrhage to 
require the attention at this time. If any large vessels are 
divided, however, they may be secured by means of pres- 
sure forceps. The periosteum elevator is next used, and the 
anterior flap, including the auricle, is forced forward so as to 
expose the upper and posterior margin of the bony meatus. 
After this has been done, it is extremely easy to secure any 
bleeding points by means of the pressure forceps. The poste- 
rior flap may also be displaced in the opposite direction, al- 
though this is frequently unnecessary, the displacement of the 
anterior flap being sufficient. It should be remembered that, 
in every case requiring operative interference, the first step is 
to enter the mastoid antrum. Even in those cases where there 
is neither tumefaction nor tenderness over the mastoid, and 
where there is distinct evidence of rupture of the abscess into 
the digastric fossa, the mastoid antrum should be entered, as 
the first step of the operation. I am well aware that in this 
advice I differ from such an eminent authority as Politzer, who 
states that it is sufficient, in certain acute cases, to enter the 
superficial cells only. No harm can result from entering the 
mastoid antrum, and not infrequently we find this pneumatic DENCH. 
3 
space involved, although there is no external evidence of this 
condition. 
Certain " landmarks " enable the surgeon to enter the antrum 
easily. These are the upper and posterior margins of the bony 
meatus. If the bone is entered above the horizontal plane of 
the superior wall of the meatus, there is danger of exposing 
the meninges in the middle cranial fossa. The distance of the 
lateral sinus from the posterior wall of the bony meatus varies 
greatly. In the majority of cases it lies half an inch behind 
the posterior margin of the bony canal. Often, however, it is 
found nearer the bony meatus, and it is therefore advisable to 
perforate the cortex as close to the posterior margin of the 
bony canal as possible. The antrum or the aditus ad antrum 
lies within a triangle, the base of which is formed by the upper 
and posterior margin of the bony canal, and whose sides are 
formed by two lines, one drawn tangent to the superior 
margin of the bony meatus, and the other drawn tangent to 
the posterior border. This small triangle may be called the 
region of safety for entering the bone. As the mastoid pro- 
cess varies considerably in contour and in thickness in different 
subjects, it is often necessary to extend the field of operation 
backward for a considerable distance. It should always be 
remembered, however, that the deepest portion of the opening 
in the bone should lie within the triangle above described. 
At the present day no surgeon would consider a mastoid 
operation complete unless the entire mastoid process had been 
thoroughly explored. In other words, it is not sufficient to 
enter the antrum, and to establish free communication with the 
middle ear, but all pneumatic spaces must be explored, from 
the mastoid antrum to the very tip of the process. Dr. Grue- 
ning, of this city, was, I think, the first to urge the necessity 
of this radical procedure, and to him, more than to any one 
surgeon, we are indebted for formulating the operative tech- 
nique in these cases. 
After the bone has been exposed in the manner described 
above, and the landmarks clearly made out, the next step is to 
completely expose the tip of the mastoid process. It is impos- 
sible to separate the sterno-mastoid muscle from the underly- 
ing bony parts by means of the periosteum elevator, and the 4 
TECHNIQUE OF THE MASTOID OPERATION. 
apex of the mastoid can only be exposed by cutting the ten- 
donous attachment as close to the bone as possible. The blunt 
scissors, curved on the flat, are best adapted for this purpose. 
They should be applied closely to the surface of the bone, and 
while in this position should be made to divide dense fibrous 
tissue at the tip of the mastoid, by a series of short cuts, until 
the finger can be passed completely beneath it and into the 
digastric fossa. Unless care is taken to keep the instrument 
closely applied to the bone, there is danger of injuring some of 
the large vessels in the neck. 
After the entire surface of the mastoid is exposed, the next 
step is to gain access to the antrum. When perforation of the 
cortex has occurred spontaneously, the opening may be en- 
larged by means of a sharp curette, the instrument being made 
to remove all softened bone, until the antrum is reached. In 
many cases, however, we find the mastoid cortex intact, and 
access to the antrum must be gained at the region of election 
above described. 
The old hand-drill has been almost entirely discarded by the 
modern surgeon, and the chisel and gouge are most frequently 
employed to remove the mastoid cortex. The dental burr is an 
instrument which has of late come into use, and is exceedingly 
efficient in some cases. Personally, I prefer to remove the 
superficial portion of the mastoid by means of the chisel or 
gouge, and to break down the deeper parts with the dental 
burr. In using the chisel, the instrument should be applied 
nearly in the horizontal plane, the bone being removed in suc- 
cessive layers, and should be directed downward and forward 
toward the bony meatus. At first it is wise to use an instru- 
ment of considerable size, removing large chips of the bone. 
As the wound becomes deeper, a smaller gouge should be used, 
it being always borne in mind that the deepest portion of the 
opening should lie in the triangle before mentioned. In this 
way, a small, funnel-shaped excavation is made, the apex lying 
just above and behind the posterior wall of the canal. The 
antrum usually lies about half an inch beneath the mastoid 
cortex. This is by no means an invariable rule, the depth be- 
ing quite frequently greater than this. As long as the opening 
in the bone is made close to the posterior wall of the meatus, DENCH. 
5 
and below the plane of the superior wall, the operator is per- 
fectly safe. Where the antrum is very small, it may lie fully 
an inch beneath the mastoid cortex. If the operator is in any 
doubt as to the advisability of entering the bone to a greater 
depth, it should be remembered that the antrum can always be 
found by separating the soft parts from the posterior and 
superior aspect of the bony meatus. The upper and posterior 
wall of the bony canal may then be removed by means of the 
chisel, and the partition between the opening already made in 
the mastoid and the osseous canal may then be broken down. 
In this way, the tympanic vault is opened and the aditus ad 
antrum exposed. This can then be followed to the antrum it- 
self, and every possible danger of injuring important structures 
may be avoided. When the antrum is not entered easily, this 
procedure should always be adopted, as it offers a perfectly 
easy and certain means of access to the mastoid antrum. When 
this pneumatic space has been entered through the cortex, in 
the ordinary way, the operator assures himself of the fact by 
passing a probe directly through the opening in the bone, 
downward, forward, and inward into the middle ear. 
After the antrum has been opened, the probe should be 
used to explore carefully the upper and posterior walls of 
the cavity. In cases of advanced suppuration, we frequently 
find that the upper or posterior wall of the space has been 
eroded by the destructive process, and it is important for 
the operator to recognize this fact early in operation. If 
the probe, passed carefully into the cavity, meets with a firm, 
bony resistance on all sides, the next step of the operation is 
to enlarge the superficial opening-that is, to break down the 
mastoid cortex in every direction, so as to expose completely 
all the pneumatic spaces. This is done by means of the chisel 
or gouge, until there is sufficient space to admit the rongeur 
forceps ; this can then be used to remove the remaining cortex. 
For opening the deeper cells, either a small gouge or the dental 
burr is exceedingly efficient. All softened bone should then 
be removed by means of the sharp spoon. Particular attention 
should be given to the aditus ad antrum. This passage should 
be thoroughly curetted, and all granulation tissue and softened 
bone removed, so that any fluid in the tympanic cavity will 6 
TECHNIQUE OF THE MASTOID OPERATION. 
drain through the posterior opening rather than into the ex- 
ternal auditory meatus. Special attention should be paid to- 
the tip of the mastoid process. In the majority of cases, we 
find a large pneumatic space at the very tip of the mastoid. It is 
therefore advisable to remove the tip of the process with the 
rongeur forceps, although this portion of the bone may appear 
perfectly healthy. It has often been my experience, in cases 
where the overlying bone had appeared normal, to find this 
large pneumatic space completely filled with soft, pulpy granu- 
lation tissue. If this is not removed, convalescence will cer- 
tainly be prolonged, and in many cases a second operation will 
be necessary. 
After all the pneumatic spaces have been explored, and all 
carious bone removed, such vessels as require attention should 
be secured with catgut ligatures. The cavity in the bone 
should then be packed with iodoform gauze, care being taken 
to carry the packing well into the aditus ad antrum, so that 
secretions from the middle ear will drain posteriorly. The 
gauze packing in the canal should then be removed, and re- 
placed by a strip of fresh gauze. It is important that this 
packing be carried to the fundus of the canal. If this is 
not done, granulation tissue may form either about the mar- 
gin of the perforation in the membrana tympani or in the 
middle of the ear, owing to the retention of secretion in the 
meatus. It is important to remember that the cavity in the bone 
is the only portion of the wound to be firmly packed, the soft 
parts being allowed to resume their normal position. In this 
way, the superficial wound closes very quickly, leaving a sinus 
leading into the mastoid process. If the superficial wound is 
packed, convalescence is prolonged, and the ear does not re- 
sume its normal position for a considerable period after the 
operation. This rule does not apply to very young children. 
In these subjects, the entire wound should be packed with 
gauze, in order to facilitate the subsequent dressings. 
The wound and the ear are then covered, first with iodoform 
gauze, then with several layers of bichloride gauze, and subse- 
quently with sterilized cotton, after which a bandage is ap- 
plied. The first dressing is allowed to remain in position for 
from five to seven days, unless there is pain or an elevation of DENCH. 
7 
temperature. It has been my experience, that these cases do 
better when dressed at rather long intervals. Any exuber- 
ant granulation tissue which may develop during the process 
of healing is removed either by means of lunar caustic or, if ex- 
cessive, by means of the scissors. At each dressing, both the 
ear and the wound are irrigated with a solution of bichloride 
of mercury, of a strength of 1:5000. In irrigation, it should 
be remembered that the wound should always be washed out 
first, to avoid infection from any accumulation of pus in the 
middle of the ear or aditus ad antrum. Another point may be 
worthy of mention here, namely, that in many of these cases it 
is by no means necessary to establish 11 through and through " 
drainage. If the opening in the mastoid cells is large, the fluid 
injected into the wound may not pass out through the external 
auditory meatus, although the probe may be passed directly 
into the middle ear. It is always unwise to employ un- 
due force to establish this return current. The operator can 
easily assure himself, by means of the probe, that the opening 
between the mastoid and the middle ear is perfectly free, and 
if this condition exists, the object of the operation has been 
attained. Where posterior drainage is perfect, the opening in 
the drum membrane closes very rapidly, and this would pre- 
vent " through " drainage on irrigation. 
The wound in the soft parts heals rapidly, and at the end of 
two or three weeks it is usually possible to dispense with the 
bandages, and to retain the dressing in position with a properly 
formed pad, thus leaving the ear exposed. If the otorrhoea 
persists, the patient is directed to irrigate the ear twice daily 
with a solution of bichloride of mercury, 1: 5000. In the ma- 
jority of cases, however, all discharge from the ear ceases soon 
after the operation, and local treatment is unnecessary. 
Regarding the dangers of the operation itself, they may be 
considered as practically nil. For this reason, it is always wise 
whenever the surgeon is in doubt as to the presence of pus in 
the mastoid process, to do an exploratory operation. If no 
pus is found, no harm has been done, while if there is deep- 
seated suppuration in the bone, delay may be- followed by the 
gravest results. 
.Certain accidents may occur during the course of the oper- 8 
TECHNIQUE OF THE MASTOID OPERATION. 
ation, in spite of the greatest care on the part of the operator. 
These are, either the exposure or opening of the lateral sinus, 
or the exposure of the meninges in the middle cranial fossa. 
None of these accidents in any way increases the danger of the 
operation, provided proper aseptic precautions have been ob- 
served. It is hardly necessary to state that, at the present 
time, no surgeon is justified in undertaking such an operation 
who is not familiar with the technique of aseptic surgery. If 
the lateral sinus is wounded accidentally, the hemorrhage is 
easily controlled by firm pressure with a pledget of gauze over 
the bleeding point. This plug is held in position by an assist- 
ant, and in the course of a few minutes the hemorrhage will 
entirely cease. Herein lies the advantage of a large opening 
in the bone in all of these cases. If the mastoid cortex is not 
removed over a large area, an accidental opening of the sinus 
makes it impossible for the operator to proceed. In other 
words, the pus in the mastoid antrum is not evacuated, and 
the patient remains unrelieved. On the other hand, if the 
cortex has been removed over a considerable area, it is possi- 
ble to control the hemorrhage from the sinus, and to continue 
the operation and enter the antrum at some other point. An 
investigation of the cases in which death has followed injury 
of the lateral sinus will show, I think, that the fatal issue has 
been due, not to the opening of the sinus, but to the retention 
of pus in the mastoid itself. In other words, the object for 
which the operation was performed had not been accomplished, 
and the patient was practically in the same condition after 
operation as before. 
My experience in a large number of cases has led me to be- 
lieve that the mere exposure of the meninges in the middle 
cranial fossa does not render the prognosis more grave. In no 
case have I seen infection occur through such an accident. 
In regard to the technique of the Stacke-Schwartze opera- 
tion, a few words may not be out of place. By this procedure 
the operator converts the mastoid cells, the vault of the tym- 
panum, and the tympanic cavity into one large chamber, con- 
tinuous with the external auditory meatus. The technique of 
the procedure is as follows : The incision through the soft 
parts is made in the manner already described in explaining DENCH. 
9 
the technique of the mastoid operation. The upper end of 
the incision is carried a little farther forward, however, to com- 
pletely detach the auricle above, thus allowing an easy exposure 
of the entire superior margin of the bony meatus. The lower 
portion of the incision over the mastoid tip is also carried 
along the anterior border of the process to allow complete 
exposure of the inferior margin of the bony meatus. The 
mastoid antrum is entered in the manner already detailed. 
The operator then dissects off the periosteum from the pos- 
terior, superior, and inferior walls of the bony meatus, as 
far as the drum membrane. The canal is then divided trans- 
versely as close to the drum membrane as possible, and 
this fibro-cartilaginous tube is forcibly drawn out of the bony 
canal by strong traction upon the auricle. This is best ac- 
complished by threading a strip of gauze through the ex- 
ternal auditory meatus and the incision in the posterior wall 
of the canal. The two ends of the gauze are then tied to- 
gether, and firm traction is made. In this way, the posterior, 
inferior, and superior walls of the bony meatus are fully exposed. 
By means of the chisel, the deep portion of the upper wall of 
the canal is cut away, thus securing free access to the tympanic 
vault. The operator then proceeds to break down the posterior 
wall of the canal, thus removing the bony partition between 
the opening already made in the mastoid and the bony external 
meatus. This is effected by means of the chisel or gouge. 
The only possible accident in carrying out this step is injury 
to the facial nerve. This may be avoided if the chisel is used 
carefully. The upper portion of the posterior wall of the 
canal should be removed first, thus exposing the aditus ad an- 
trum. The facial nerve lies close to the posterior margin of 
the tympanic ring at the junction of the upper and middle 
third. If the posterior wall of the canal is not destroyed be- 
low this point, no injury can be done to the facial trunk. It 
is hardly necessary to say that the operator must be careful 
not to injure this structure where it crosses the middle ear in 
the aqueductus Fallopii. Such an injury can hardly occur, 
however, if even ordinary care is exercised during the opera- 
tion. After the mastoid cells and the tympanic vault have 
been converted into a large cavity, which is really a dilated 10 
TECHNIQUE OF THE MASTOID OPERATION. 
bony external meatus, all carious bone should be removed from 
the middle ear and mastoid, by means of the curette. The 
instrument should be used with care, so as not to wound im- 
portant structures, and the operative field should be kept con- 
stantly in view. This is easily done if the parts are sponged 
rapidly. By drawing the auricle well forward, the remnant of 
the drum membrane and the ossicles are easily seen. It is 
seldom that the carious process destroys the ossicles com- 
pletely, the head of the malleus and a portion of the incus 
being usually left, even in cases where the disease has lasted 
for a long time. The fragments of the ossicular chain should 
be removed carefully, by means of the forceps, care being 
taken to separate them from the stapes, so as to avoid any in- 
jury to the labyrinth. In curetting the internal wall of the 
middle ear, the operator should direct an assistant to watch 
carefully the face of the patient, so that any contraction of the 
facial muscles may be recognized at once. A sudden contrac- 
tion of the facial muscles, upon the affected side, is due to a 
mechanical irritation of the trunk of the nerve by the curette. 
If this precaution is taken, serious injury to the trunk of the 
nerve is practically impossible. Particular attention should be 
given to the condition of the tympanic roof, and all softened 
bone should be removed. 
The next step is to replace the auricle, and to line the large 
cavity continuous with the bony canal with integument. This 
is done by reflecting flaps of the cutaneous lining of the bony 
meatus into this large space. Several methods have been sug- 
gested in regard to the manner of forming these flaps. My 
experience has been that the conditions vary so much in differ- 
ent cases as to make the application of any special rule im- 
possible. 
Certain rules, however, are applicable to all cases. The 
fibro-cartilaginous canal, which had been displaced forward 
during the operation, is split horizontally along the posterior 
wall. This incision may be made either in the median line or 
above or below this, according to the particular conformation 
of the parts. In this way, two triangular flaps are formed, one 
of which is forced upward into the mastoid antrum and the 
other downward into the lower part of the mastoid. The DENCH. 
11 
most common error is to make this incision too short. No 
damage is done if the incision extends as far as the middle of 
the concha. If it seems desirable, a second cut may be made 
at right angles to this first incision, thus permitting the flaps to 
be more accurately applied to the cavity in the bone. It is 
sometimes wise to remove a portion of the cartilaginous 
framework of the meatus and auricle, leaving only the integ- 
ument to form the lining of this bony cavity. It is my usual 
practice to unite the periosteum lying just behind the bony 
opening to adjacent portions of the flaps formed as above de- 
scribed, by means of deep sutures either of boiled silk or silk- 
worm gut. The ends of these sutures are left long and either 
carried into the meatus or brought out through the wound, 
in order to admit of easy removal. The superficial wound 
is then closed throughout by means of interrupted sutures. 
These sutures may be either of catgut, silkworm gut, silk, 
or silver wire, my own preference being boiled silk. It is 
important, in closing the lower portion of the wound, to 
completely obliterate the " dead space " formed by the re- 
moval of the tip of the mastoid. If this is not done, the 
serous effusion from the wound drains into this space and 
complete primary union is seldom obtained. This space may 
be obliterated either by passing a silk suture very deeply, so as 
to include the divided tissues throughout the entire depth of 
the wound, or by uniting the deep tissues with buried sutures 
of fine catgut, the superficial wound being closed in the man- 
ner stated above. The cavity in the temporal bone resulting 
from the amalgamation of the mastoid cells and tympanic 
vault is then firmly packed with iodoform gauze introduced 
through the external auditory meatus ; care should be taken 
to completely fill the cavity. If this point is not observed, ex- 
uberant granulations may spring up from the denuded surface, 
and delay the convalescence. The entire ear and the field of 
operation are then covered with an antiseptic dressing, which 
is allowed to remain in place for six or seven days, unless 
pain or temperature indicate that its removal is necessary. 
At the end of this time, the superficial sutures should be 
removed. The deep sutures which have been carried either 
into the canal or through the wound are allowed to remain 12 
TECHNIQUE OF THE MASTOID OPERATION. 
undisturbed and usually come away on the tenth or twelfth 
day. It is seldom necessary to change the dressing more 
frequently than every fourth or fifth day. At each dressing 
the cavity is thoroughly irrigated by means of an antiseptic 
solution. The parts are then dried by means of sterilized 
cotton, and the packing replaced in the manner already de- 
scribed. Where the superficial parts unite by first intention, 
the bandage can be dispensed with at the end of ten or four- 
teen days. It is then sufficient to protect the line of incision 
behind the ear with a few strips of sterilized gauze, held in po- 
sition by collodion. The patient is directed to syringe the ear 
twice daily, in order to keep the parts thoroughly cleansed. Any 
exuberant tissue which may develop is destroyed by means of 
nitrate of silver or chromic acid. The discharge from the 
canal may not cease entirely for several months. It is usually 
insignificant in quantity, however, at the end of three or four 
weeks. When the discharge is very slight, the syringing may 
be dispensed with entirely, and the granulating surface covered 
with a thin layer of boric acid or a mixture of equal parts of 
boric acid and iodoform. 
A word should be said in regard to the selection of cases to 
be subjected to this operative procedure. Where caries is lim- 
ited to the ossicles, and to those parts of the middle ear 
which can be reached by the instruments introduced into the 
meatus, I am decidedly of the opinion, that the removal of the 
carious ossicles and thorough curettement of the middle ear 
through the canal is followed by equally satisfactory results. 
Where, however, the disease has extended to the mastoid 
process, there is no possibility of curing the aural discharge 
without performing the more radical operation already de- 
scribed. It has been frequently claimed that the posterior 
incision gives the operator a better view of the tympanum than 
can possibly be obtained through the canal. This, I think, is 
a mistake, and as far as the operation upon the tympanum it- 
self is concerned, the surgeon will be able to work much more 
exactly through the canal than through the posterior opening. 
The choice of operation, therefore, should depend entirely upon 
the extent to which the bone is involved. If the tympanum alone 
is affected, the simpler operation is unquestionably preferable. DENCH. 
13 
In 74 cases the ossicles were removed and the tympanum 
thoroughly curetted, with the following result: Cured, 46 ; 
improved, 19 ; result unknown, 8. In one case the result 
seemed satisfactory at first, but later a Stacke-Schwartze 
operation was required. 
In 14 cases the Stacke-Schwartze operation was performed: 
Cured, 9 ; improved, 4 ; under treatment, 1. 
Although it hardly lies within the scope of this paper to dis- 
cuss any operative measures for the relief of intra-cranial com- 
plications, these are so common in mastoid suppuration that 
the author feels justified in alluding briefly to the operative 
technique in these cases. When the surgeon believes that 
there is involvement of the lateral sinus, as evidenced by sud- 
den and pronounced elevation of temperature followed by 
spontaneous defervescence, he is warranted in exposing the 
lateral sinus, as this is the channel most frequently involved 
in mastoid inflammation. The location of the vessel, as be- 
fore stated, varies considerably in different subjects. Most 
frequently the sinus will be exposed by entering the cranial 
cavity at a point half an inch behind the posterior wall of the 
meatus. It is hardly necessary to say that the most rigid asep- 
tic precautions should be taken when it is the intention of the 
operator to expose this venous channel. The vessel may lie 
either in front or behind the normal situation ; it is best ex- 
posed by means of a large gouge or by the dental burr. While 
I would not favor the careless use of instruments in this 
region, it is not necessary to greatly prolong the operation to 
expose this vessel. If the gouge is used, a few blows of the 
mallet will suffice to remove the inner table of the skull. After 
the cranial cavity has been entered, the rongeur forceps should 
be employed to enlarge the opening upward and downward, 
and if the sinus is not immediately recognized, the wound 
should be enlarged backward with the same instrument. It is 
never wise to open the venous trunk without first exposing it 
for a considerable distance. Tactile exploration goes far in 
determining whether the lateral sinus is normal or whether it is 
occluded by a thrombus. In many cases, however, the opera- 
tor is in doubt, and in these instances it is justifiable to intro- 
duce a sterilized aspirating needle into the sinus. If normal 14 
TECHNIQUE OF THE MASTOID OPERATION. 
fluid blood is withdrawn, there is every reason to suppose that 
the channel is patent, and that further operative procedure is 
not required. If, however, no blood is withdrawn on explora- 
tory puncture, or if aspiration yields a few drops of foul- 
smelling pus or blood, the operator should open the sinus 
freely. This is best done by making a short longitudinal in- 
cision with a small scalpel, and enlarging it with a small blunt 
scissors. If a thrombus is found, it is removed by means of a 
small curette. As a rule, I carry the curette downward toward 
the jugular bulb, removing the deeper portions of the throm- 
bus until free hemorrhage occurs from below. In many cases 
the clot will be so extensive as to render it necessary to expose 
the sinus for a greater distance. In two instances I have fol- 
lowed it downward and forward to within an eighth of an inch 
of the jugular bulb before the occlusion was relieved and free 
venous hemorrhage occurred. As soon as this takes place, a 
strip of iodoform gauze is forced into the lumen of the sinus 
and packed firmly downward by means of the probe. This 
controls the hemorrhage easily. This tampon is held in posi- 
tion by an assistant who exerts rather firm pressure upon it. 
The operator then explores the sinus in the opposite direction, 
towards the torcular Herophili. If necessary, the bone is re- 
moved in a direction upward and backward, and the wound in 
the sinus enlarged until curettement is followed by free hem- 
orrhage. This end of the wound is then packed with iodoform 
gauze in the manner already described. After firm pressure 
upon these tampons for a few moments, they are removed, and 
the open sinus is washed out thoroughly with a normal salt 
solution. It is an advantage, I think, to allow the sinus to 
bleed rather freely, as, in this way, any detached fragments of 
the thrombus are expelled by the blood current. Where it is 
necessary to follow the sinus downward to the jugular bulb, it 
is wise to have an assistant compress the internal jugular in the 
neck, so as to prevent the entrance of air into the vein. Such an 
accident has happened in one or two cases reported, and is 
always to be guarded against. After thoroughly cleansing the 
sinus, it is firmly tamponed with iodoform gauze. In dressing 
the wound, it is important to protect the exposed sinus as com- 
pletely as possible. This is best effected by packing the mas- DENCH. 
15 
toid cavity in the usual manner, without disturbing the tampon 
in the blood-vessel. After this has been done, the anterior por- 
tion of the wound is covered with a gauze sponge, and the gauze 
occluding and covering the sinus is removed. This portion of 
the wound is then packed with fresh iodoform gauze. The sinus 
is thus completely isolated from the middle ear and mastoid 
antrum, and no infection can possibly occur. At the time of 
the first dressing, it is wise to leave the packing about the 
sinus undisturbed until the gauze has been removed from the 
mastoid antrum, and the parts are completely cleansed with an 
antiseptic solution. The aditus ad antrum, and the antrum 
itself, is then loosely packed with a strip of iodoform gauze, 
covered with a cotton sponge, and the sinus wound dressed 
separately. This portion of the wound is then packed as above 
described, after which the temporary tampon in the mastoid is 
removed, and the dressing is completed in the usual manner. 
Secondary hemorrhage from the sinus, either a few hours 
after the operation, or at the time of the first dressing, is a rare 
occurrence, and I have never observed it in my own practice. 
In certain cases the surgeon is not consulted until the evi- 
dences of systemic infection have existed for some time, and 
the thrombus may have extended from the sinus into the inter- 
nal jugular vein. This condition is characterized by tender- 
ness along the anterior border of the sterno-mastoid muscle, 
and by the presence of a hard cord-like band, easily recognized 
upon palpation, following the course of the internal jugular. 
The overlying tissues are also somewhat swollen, and the 
patient usually complains of spontaneous pain in this region. 
In any case of suspected sinus thrombosis the neck should 
always be examined, as jugular involvement may follow occlu- 
sion of the sinus in a very short time if the septic process is 
virulent in character. 
If the vein is occluded, it must be exposed and divided be- 
tween two ligatures as low down as possible to prevent sys- 
temic infection. It is also wise to ligate both the facial vein 
and the short trunk which joins the external jugular to the 
internal. The sinus is dealt with in the manner previously de- 
scribed. It should be remembered that hemorrhage from 
below on opening the sinus does not prove that the jugular is 16 
TECHNIQUE OF THE MASTOID OPERATION. 
free. Even if the vein is completely occludvd, free bleeding 
may occur, the source of the hemorrhage being the inferior 
petrosal sinus. 
Occasionally the sinus will be found occluded by a firm or- 
ganized clot and all efforts to restore its patency fail. When 
this condition exists the symptoms of systemic infection are 
wanting, and there is no indication for ligation of the jugular. 
The organized clot is the result of a previous inflammatory 
process and is an evidence that there is no danger of general 
infection. 
Where the symptoms are so obscure as to render the location 
of an intra-cranial lesion a matter of conjecture, it is impor- 
tant, I think, to render it possible to expose, through a single 
incision in the soft parts, the mastoid antrum, the lateral 
sinus, the middle cranial fossa and the cerebellar fossa. It 
should be remembered that time is an important element in 
these operations. If the operation is so conducted as to 
render several incisions through the soft parts necessary, the 
hemorrhage from the superficial tissues causes considerable 
delay, and the procedure is unnecessarily prolonged. I 
also differ from many eminent authorities as to the advis- 
ability of first entering the mastoid antrum in all cases. Where 
the symptoms seem to indicate distinctly that the lesion is in 
either the middle cranial fossa or in the cerebellum, it is un- 
questionably wise to relieve this condition immediately. It 
is true that the process has extended from the middle ear or mas- 
toid, but the immediate symptoms are due to the intra-cranial in- 
volvement. Frequently the patient is in no condition to warrant 
a prolonged operation. If the intra-cranial condition is first re- 
lieved, recurrence may be prevented by a second operation upon 
the mastoid and middle ear. In all cases, therefore, where intra- 
cranial involvement is suspected and the patient is very weak, 
the incision is made as follows : The knife is entered just be- 
low the tip of the mastoid and carried down to the bone. It is 
then carried upward, following the line of insertion of the 
auricle, and forward as far as the external angular process of 
the frontal bone. From a point just above the auricle, a sec- 
ond incision is made downward and backward to a point just 
below the occipital protuberance. In this way free access may DENCH. 
17 
be gained to the middle cranial fossa, the middle ear and mastoid 
antrum, the lateral sinus and the cerebellar fossa. In forming 
the posterior flap, the periosteum is not disturbed, the soft 
parts alone being reflected. Where there is special need of 
rapidity, it is convenient to apply T-clamps to the margins 
of the flaps, thus quickly controlling the hemorrhage. If 
the location of the intra-cranial lesion is obscure, and the 
patient is in good condition, the first step is to rapidly enter 
the mastoid antrum by means of the chisel; if the patient is 
weak, this may be omitted. If sinus involvement can be ex- 
cluded, this vessel need not be exposed, and the first step 
should be to enter the middle cranial fossa. This is done 
by exposing the squamous portion of the temporal bone 
above the zygoma and just in front of the external auditory 
meatus. The periosteum is separated with the elevator and the 
cranial cavity is easily entered by means of the gouge, a few 
strokes of the mallet sufficing to perforate the bone. This 
opening is enlarged downward and backward by means of the 
rongeur forceps until the index finger can be introduced into 
the cranial cavity. If infection has taken place through the 
tympanic roof, and an extra-dural collection of pus is present, 
this can be evacuated by passing the finger along the upper 
surface of the petrous pyramid and carefully separating the 
meninges from the underlying bone. This should be done as 
a primary procedure. If no pus is found, the dura is raised 
by means of toothed forceps, and divided with delicate scissors, 
so as to form a curvilinear flap. This flap is deflected down- 
ward, and the brain substance explored in various directions 
by means of the aspirator, for the purpose of detecting any 
intra-cranial collection of pus. If the result of the exploration 
is negative, the wound is washed with a sterilized normal salt 
solution, and the edges of the dura brought together by sutures. 
The soft parts are allowed to fall naturally over the opening in 
the bone, and a towel moistened in 1:3000 bichloride is placed 
over the entire wound. 
If the sinus is to be exposed, the operative technique already 
detailed is followed. If it seems desirable to explore the cere- 
bellar fossa, the cranial cavity is entered at a point about two 
and a half inches behind the centre of the meatus, and about a 18 
TECHNIQUE OF THE MASTOID OPERATION. 
quarter of an inch below this level. Roughly speaking, the 
opening is made between the superior and inferior curved 
lines of the occipital bone. In this locality the skull is very 
thin and is easily perforated by a large gouge. The wound is 
then enlarged with the rongeur forceps, and a dural flap re- 
flected and the exploration of the cerebellum conducted as 
already described. 
If an extra-dural collection of pus is found in exploring the 
middle cranial fossa, and if the surgeon considers this sufficient 
to explain the symptoms of the patient, no further operative pro- 
cedure is necessary. After the pus has been evacuated, the next 
step is to enter the mastoid antrum, unless this has already been 
opened. After the antrum has been freely opened, the upper 
wall of the canal, which forms the floor of the middle cranial 
fossa, is broken down with the rongeur forceps, to facilitate free 
drainage. A narrow strip of iodoform gauze is then carried 
to the deepest portion of the wound and the entire cavity is 
thoroughly packed. The antrum and the middle ear must be 
isolated from the exposed dura in the manner already de- 
scribed in considering sinus thrombosis. 
If a brain abscess is found in the temporo-sphenoidal lobe, or 
in the cerebellum, the exploring needle is allowed to remain in 
position, and, with this as a guide, a sharp knife is passed into the 
brain substance, and made to incise this sufficiently to admit of 
the introduction of the index finger. This is carried carefully 
into the abscess cavity, and all softened tissue broken down. 
Many operators, notably McEwen, advocate the packing of 
the abscess cavity with a mixture of iodoform and boric acid. 
My own practice, however, has been to carry a narrow strip 
of iodoform gauze into the cavity, securing drainage by this 
method. If the incision through the dura has been extensive, 
-and this, I think, is always wise,-it may be partially closed 
by means of sutures, sufficient space being left for the passage 
of the gauze drain, and to allow free access to the abscess 
cavity at subsequent dressings. The external wound should 
not be closed throughout its entire extent, the lower and an- 
terior angles alone being brought together by means of strong 
silk sutures. The remainder of the superficial wound is packed 
lightly with gauze, so as to allow easy access to the deeper DENCH. 
19 
parts. An antiseptic dressing is applied over the entire field 
of operation, and this is not disturbed for six or seven days, 
unless urgent symptoms indicate that its removal is necessary. 
The advantage claimed for this method of procedure is that 
the time of operation is shortened considerably. With a little 
experience, it is possible to open the mastoid antrum, expose 
the lateral sinus, the middle cranial fossa, and the cerebellar 
fossa, and to complete the entire operation in one hour, or 
even less. The point to be emphasized is, that the surgeon 
should have a definite idea of what he is going to do before the 
operation is begun, and that no time should be lost in dis- 
cussing the possibilities and probabilities after the cranial 
cavity has once been entered. Anyone conversant with trau- 
matic surgery of the brain knows that exposure of the meninges, 
and of the brain itself over a considerable area, is not serious, 
provided the parts are kept thoroughly aseptic, and the ex- 
posure is not prolonged. I think that many of these cases 
would recover if the time of operation could be shortened, thus 
diminishing the shock. 
In support of the position assumed by the author, the follow- 
ing record of his own operative work is added : 
Mastoid operations, 192 1 : Cured, 183 ; died, 9. 
Acute meningitis, 1, cured. 
Mastoid cases, with intra-cranial complications : (a) Epidural 
abscess, 8 cases, cured. (^) Sinus thrombosis, 9 cases ; cured 
8 ; died 1 (death due to acute nephritis). (f) Brain abscess, 1 
case, death. 
The fatal issue in the remaining 7 cases was probably due 
to the following conditions, although a necropsy was not 
possible in every case : Facial erysipelas, 1 ; meningitis, 3 ; 
abscess of brain, rupturing into lateral ventricles, 2 ; acute 
nephritis, 1. 
' This does not include the cases operated upon by the Stacke-Schwartze 
method, and previously reported. Ube tknickerbocfeer press, IRcw l?ork