Clinical Otolaryngology 1978, 3, 43 1-435
Tympanoplasty: the fundamentals of the concept* HORST L. WULLSTEIN Praxisklinik Wullstein, Oberer Neubergweg roa, D-8700Wurzburg, West Germany
Accepted jor publication 17 February 1978
WULLSTEIN H.L. (1978) Clinical Otolaryngology 3, 431-435 Tympanoplasty : the fundamentals of the concept The development of tympanoplasty based on a fundamental understanding of the mechanisms of the middle ear in health and disease is described as it evolved. As a consequence of problems arising from the creation of an open cavity further developments led to the concept of a 'closed' operation which in turn has its own disadvantages. These are principally concerned with aeration of the tubotympanic cleft. The most recent phase of tympanoplasty is concerned with limiting the extent of the procedure to what is required to expose the disease process and re-establish function. Keywords tympanoplasty ventilation functional restoration
The basic requirement for tympanoplasty is the complete separation of the inside ventilation system of the middle ear from the outside to restore the physiological conditions of temperature and moisture for a healthy inner surface, the mucosa, the main prerequisite for a functional middle ear. The best proof of this concept is the fact that longstanding chronic mucopurulent secretion arising from tubotympanic infections does not heal in any better way than by successful tympanoplasty. The air passing into the new middle ear through the normal way via the Eustachian tube and not via the external meatus helps to restore the function of the tube: it is also warmed and moistened to the physiological degree which the small amount of air needs for the closed tympanic cavity instead of the continuous loss of temperature, moisture and gas content via the open meatus. The abundance of goblet cells which were developed in the meantime became useless and, therefore, they decrease quickly to the normal small amount along the routes of ventilation. At the same time chronic oedema and infiltration shrink and the mucosa returns to normal as far as possible. That is why I insisted in 1952-53 that tympanoplasty is the best, and almost the only way to stop severe chronic tubotympanic discharge, especially in children, in strong contradiction to the rules for plastic surgery.6 In addition to the condition just mentioned of chronic otitis media there must be air inside the new middle ear so that the mucosa will be rehabilitated and the small apertures and gaps, especially in between the ossicles, will be reopened. If they are not kept open, new broad
* Read at the first international meeting of the Politzer Society, February 1978. 0307-7772/78/11oo-o~~ I $02.00 0 1 9 7 8 Blackwell Scientific Publications
431
432
HORST L . W U L L S T E I N
adhesions cannot be prevented. IJltimately, the ossicles must be sacrificed, and a simple type I11 will be the best possible chance left. The one-stage tympanoplasty was a decisive landmark in otosurgery. Antibacterial therapy preoperatively has few benefits. Locally, as well as parenterally, it will not reach the small hidden suppurative cysts or enter into the compact cholesteatomata masses where we must expect anaerobic bacteria as well as pseudomonas aerogenosus and proteus vulgaris. The problem was solved with the help of the ‘tissue culture in vzvo’, which I used for the survival of the graft. The solution is prevented from being drained too quickly via the tube and the graft supported with the help of the skeleton of saturated gelfoam. T o this tissue culture is added one of the antibiotics available against the infections mentioned. An extremely high concentration of antibiotic is reached immediately for about 1 2 hours, then decreases. I n the meantime antibiotics given parenterally for several days become effective. An antiseptic is added to the fluid for irrigation during the long manipulations in the middle ear, but not if a labyrinthine fistula is present or one window has to be opened (from that point, Ringer’s solution is used). Attempts to restore the tympanic membrane were made starting with Thiersch grafts which do not contain any elements for survival. These include the methods which made use of the concept to reconstruct a membrane with the help of biplane epidermal flaps. As an inner surface, flaps of the skin of the outer meatus pediculed on the annulus were used, and as the outer surface a flap prolonged from the mastoid and inserted via a radical cavity. Both methods failed and were dropped shortly after their publication. Once it was shown that the risk of inner ear infection was nearly non-existent one-stage surgery was immediately accepted. Tu-o-stage surgery is unavoidable to regain a closed and healthy middle ear cavity so that the sound pressure transformation system to the inner ear can be restored in a second stage, for example with stapedectomy. From this very moment on the surgeon has been able to perform plastic procedures in the middle ear and mastoid ad libitum, as far as the newly constructed tympanic membrane is concerned. Since it was proven that the inner surface of a free standing new membrane quickly overgrows with epithelium, it was obvious that the same would happen on the outside where it could even be accessible to observation. This meant that any kind of a membrane with simple structure could be taken into consideration. One main subject of tympanoplasty since the very beginning has been to handle the cholesteatomata. Because we must eradicate every islet of matrix we cannot hesitate to end up with large defects of the surface or naked bone even without periosteum. In cholesteatomata either healthy mucosa is available to spread over the defect or we must provide a grafting of a suitable mucosa. Again, we are in need of every bit of healthy mucosa, for example in the depth of the window niches and around the ossicles and, especially, along the 2 pathways of ventilation through the 2 bottle-necks of aeriation on the way to the antrum. Tynipanoplasty in cholesteatomata is prophylactic surgery. Many cholesteatomas do not penetrate into the antrum but are restricted within the epitympanum and aditus. We must deal with 6 types of cholesteatomata:
Tympanoplasty
433
I The real immigration type of Habermann3 and Bezold4 mainly following severe, necrotic otitis media with large marginal perforations. This is now rare in countries with high medical standards, but is certainly common in others. 2 The primary-papillary cholesteatomata vi hich initially is nearly always a hidden or occult primary cholesteatoma without perforation. 3 The retraction or invagination cholesteatomata.
(The following
2
are iatrogenous types of cholesteatomata.)
4 The recurrent cholesteatoma, an atypic group of invagination cholesteatomata. 5 The residual cholesteatomata deriving from an islet of matrix left behind during surgery. 6 The paralabyrinthine cholesteatomata spreading into the petrous bone and the labyrinthine after penetrating via a fistula. Compared to the high percentage of recurrent and residual cholesteatomata after surgery the latter are rare, but they nearly always end up with the loss of the inner ear function, if surgery is not performed very early. Tympanoplasty is required primarily for elucidation of the different forms of osteitis of the bony capsule of the inner ear and the surrounding petrous bone. For more than 10 years I occupied myself with the pathology on the border line of middle and inner ear in the course of labyrinthitis including monthly functional tests, X-rays and cerebrospinal fluid findings and in correlation with histological series sections. Eventually in a monograph of 1948,5 I was able to close the last gap between inner ear pathology and clinical findings to define exactly every kind of bony destructions and their course : a Acute total osteitis of the inner ear lasting 3 months until spontaneous healing is the most dangerous form. b Independent endosteal osteitis, acute or chronic. c Circumscribed chronic osteitis, so-called fistula, mostly, but not always of the lateral semi-circular canal. d Inner ear and paralabyrinthine cholesteatomata in the petrous bone. e Genuine sequestration of the bony inner ear which is extremely rare.
The antibiotics just coming into the market seduced the otologists to neglect this classification. It is an astonishing fact that only petrous bone cholesteatomata aroused clinical interest anew. These can penetrate deeply with or without the typical roots and can even spread via a small defect through the cortex on the floor of the middle cranial fossa. Furthermore, they are the only consequences of ear inflammation which can never heal spontaneously. They may remain uninfected for long periods of time. That is why antibiotics in the case of the cholesteatomata can prevent diffuse labyrinthitis. Despite large defects of the bony capsule inner ear function persists. Once X-ray shows the first findings of an early inner ear or petrous bone cholesteatomata it is too late to save function, and partial resection of the inner ear is unavoidable. This is why I returned to the view that we must see the spongiotic bone in front and behind the anterior semicircular canal as the ‘points of danger’. Looking at choles-
431
HORST L . W U L L S T E I N
teatomata this way it is obvious that the so-called recurrent and residual ones will show up carlier, the paralabyrinthine much later. Paralabyrinthine cholesteatomata grow slowly and in a silent manner. To reconstruct the middle ear regardless of mucopurulent infection or cholesteatomata in one stage, or with the sound pressure transformation in a second stage, demands a knowledge of the extent of the disease without opening more of the middle ear than necessary. The findings in the mesotympanum even with X-ray are insufficient for this purpose. X-ray cannot differentiate between a wide healthy antrum and a large cholesteatoma; a small perforation makes it impossible to envisage the middle ear. T o avoid the open cavity, in 1953 I introduced control holes: one via the meatus into the aditus to check the passage where infection must go through on the way to the antrum and mastoid (the so-called aditus control), the other one via a mastoidectomy and the facial-chorda-angle into the sinus tympani and the facial recess with a view directly on the round window membrane (the so-called round window control). They both proved not to be sufficient in every case.6 The surgical methods to avoid the open cavity in nearly every case can be grouped in a sequence sacrificing more or less of the bony walls.
Group I Endaural radical mastoidectomy with preservation of some kind of bony bridge or pillar to stretch over soft tissue membranes as new walls. Group 2 Posterior tynipanotomy, intact canal wall technique through the cortex of the mastoid to the antrum and via the facial-chorda-angle in the sinus tympani and facial recess (following in the steps of the posterior control combined with the so-called atticotomy). Group 3 The same large transmastoidal access also, but combined with temporary resection and reimplantation of the posterior bony canal wall. The latest version of this technique is to saw out the posterior wall along the roof of the bony meatus, thus exposing middle ear and mastoid very extensively in each case and refixing the complete bony posterior and superior wall very solidly in a slot. Group 4 Suprameatal access-osteoplastic epitympanotomy directly attacks the main focus in the epitympanum and surgery is expanded only so far as really necessary with immediate reconstruction of the bony wall.
A great number of surgeons strongly advocate group 2 , only some of them have the great skill and perseverance for long-lasting good results in one stage. Two kinds of disappointing outcomes became known as recurrent and residual cholesteatomata. The reason why the z are sequences of the method can be explained : I The so-called closed technique leaves the posterior bony wall intact as far as the external meatus is concerned, but it destroys the posterior mesotympanum completely. Therefore the air no longer ventilates through the inferior ventilation route via the bottle neck of the posterior isthmus tympani into the epitympanum and antrum. Instead it falls directly in the
Tympanoplasty
435
mastoid cavity and does not act as counter pressure against the tympanic membrane thus causing a so-called retraction or invagination cholesteatoma. In surgery complete safe closure for gas or fluid can only be accomplished by solid tissue growth, not by any insertion of alloplastic material. z The reports on the findings of the residual cholesteatomata tells us that they are not of the epitympanal and paralabyrinthine type of cholesteatomata. The majority are found in the mesotympanum. Even the combination of the 2 approaches from behind and via the meatus does not guarantee the certainty necessary to detect every small islet of matrix in the area of the hidden bony niches and the interossicular folds. In our opinion the best surgical method in cases of chronic otitis media should make it possible : a To attack the main focus from the side of its origin, not from behind, to expose it at first directly and to study in detail the course of development. b To expose the area involved completely but not further than necessary, maybe the epitympanum only together with the mesohypotympanum, maybe on the contrary combined with the whole extent of the mastoid. c On the other hand not to expose any area of the pneumatic system clothed with healthy or nearly healthy mucosa as is true in a very high percentage for the antrum and mastoid. d To regain the normal ventilation routes in the middle ear, the upper and especially the lower one-which represent the decisive elements of function of the tympanum. The posterior bony wall of the outer meatus as well as that of the sinus tympani has to be left intact. e With this direct view the utmost care can be taken during the dissection to preserve every bit of mucosa and to create a situation for it to heal and to normalize. A wide access makes it easier and safer to reconstruct the sound pressure transformer at the same time. Above all, the search for the pathology and, especially, for every islet of matrix predominates, With these facts in mind it seems that the methods of Feldmann’ and S. R. Wullstein2 offer the best chance to get rid of the disease as thoroughly as possible in one stage. The latter is the only one which can be ‘made to measure’ to adapt to the pathology and does not need access through the mastoid and so that mucosa is not destroyed unnecessarily. References I
2
3 4 5
6
FELDMANN H. (1977) Eine Stichsage fur die Mikrochirurgie, neue Moglichkeiten zu osteoplastischen Eingriffen am Ohr und den Nebenhohlen. Archiv fur Ohren-Nasen und Kehlkopfheilkunde 2 1 6 , ~ . WULLSTEIN S.R. (1973) Die osteoplastische Epitympanotomie und die Pathologie des Mittelohres. I . Teil das operative Vorgehen. Zeitschr$t f i r Laryngologie, Rhinologie Otologie 52, 34. HABERMANN J. (1889) Zur Entstehung des Cholesteatoms des Mittelohres. Archiv Ohrenheilkunde 27,42. BEZOLD F. (1891) Ober das Cholesteatom des Mittelohres. Zeitschrift Ohrenheilkunde 21, 252. WULLSTEIN H.L. (1948) Die Klinik der Labyrinthitis und Paralabyrinthitis auf Grvnd des Rontgenbef undes. George Thieme, Stuttgart. WULLSTEIN H.L. (1952) Die Eingriffe zur Gehozerbesserung. Abschnitt in Uffenorde: Anzeige und Ausfuhrung der Eingriffe an Ohr, Nase und Hals, 2. Aufl. George Thieme, Stuttgart.
Tympanoplasty: the fundamentals of the concept* HORST L. WULLSTEIN Praxisklinik Wullstein, Oberer Neubergweg roa, D-8700Wurzburg, West Germany
Accepted jor publication 17 February 1978
WULLSTEIN H.L. (1978) Clinical Otolaryngology 3, 431-435 Tympanoplasty : the fundamentals of the concept The development of tympanoplasty based on a fundamental understanding of the mechanisms of the middle ear in health and disease is described as it evolved. As a consequence of problems arising from the creation of an open cavity further developments led to the concept of a 'closed' operation which in turn has its own disadvantages. These are principally concerned with aeration of the tubotympanic cleft. The most recent phase of tympanoplasty is concerned with limiting the extent of the procedure to what is required to expose the disease process and re-establish function. Keywords tympanoplasty ventilation functional restoration
The basic requirement for tympanoplasty is the complete separation of the inside ventilation system of the middle ear from the outside to restore the physiological conditions of temperature and moisture for a healthy inner surface, the mucosa, the main prerequisite for a functional middle ear. The best proof of this concept is the fact that longstanding chronic mucopurulent secretion arising from tubotympanic infections does not heal in any better way than by successful tympanoplasty. The air passing into the new middle ear through the normal way via the Eustachian tube and not via the external meatus helps to restore the function of the tube: it is also warmed and moistened to the physiological degree which the small amount of air needs for the closed tympanic cavity instead of the continuous loss of temperature, moisture and gas content via the open meatus. The abundance of goblet cells which were developed in the meantime became useless and, therefore, they decrease quickly to the normal small amount along the routes of ventilation. At the same time chronic oedema and infiltration shrink and the mucosa returns to normal as far as possible. That is why I insisted in 1952-53 that tympanoplasty is the best, and almost the only way to stop severe chronic tubotympanic discharge, especially in children, in strong contradiction to the rules for plastic surgery.6 In addition to the condition just mentioned of chronic otitis media there must be air inside the new middle ear so that the mucosa will be rehabilitated and the small apertures and gaps, especially in between the ossicles, will be reopened. If they are not kept open, new broad
* Read at the first international meeting of the Politzer Society, February 1978. 0307-7772/78/11oo-o~~ I $02.00 0 1 9 7 8 Blackwell Scientific Publications
431
432
HORST L . W U L L S T E I N
adhesions cannot be prevented. IJltimately, the ossicles must be sacrificed, and a simple type I11 will be the best possible chance left. The one-stage tympanoplasty was a decisive landmark in otosurgery. Antibacterial therapy preoperatively has few benefits. Locally, as well as parenterally, it will not reach the small hidden suppurative cysts or enter into the compact cholesteatomata masses where we must expect anaerobic bacteria as well as pseudomonas aerogenosus and proteus vulgaris. The problem was solved with the help of the ‘tissue culture in vzvo’, which I used for the survival of the graft. The solution is prevented from being drained too quickly via the tube and the graft supported with the help of the skeleton of saturated gelfoam. T o this tissue culture is added one of the antibiotics available against the infections mentioned. An extremely high concentration of antibiotic is reached immediately for about 1 2 hours, then decreases. I n the meantime antibiotics given parenterally for several days become effective. An antiseptic is added to the fluid for irrigation during the long manipulations in the middle ear, but not if a labyrinthine fistula is present or one window has to be opened (from that point, Ringer’s solution is used). Attempts to restore the tympanic membrane were made starting with Thiersch grafts which do not contain any elements for survival. These include the methods which made use of the concept to reconstruct a membrane with the help of biplane epidermal flaps. As an inner surface, flaps of the skin of the outer meatus pediculed on the annulus were used, and as the outer surface a flap prolonged from the mastoid and inserted via a radical cavity. Both methods failed and were dropped shortly after their publication. Once it was shown that the risk of inner ear infection was nearly non-existent one-stage surgery was immediately accepted. Tu-o-stage surgery is unavoidable to regain a closed and healthy middle ear cavity so that the sound pressure transformation system to the inner ear can be restored in a second stage, for example with stapedectomy. From this very moment on the surgeon has been able to perform plastic procedures in the middle ear and mastoid ad libitum, as far as the newly constructed tympanic membrane is concerned. Since it was proven that the inner surface of a free standing new membrane quickly overgrows with epithelium, it was obvious that the same would happen on the outside where it could even be accessible to observation. This meant that any kind of a membrane with simple structure could be taken into consideration. One main subject of tympanoplasty since the very beginning has been to handle the cholesteatomata. Because we must eradicate every islet of matrix we cannot hesitate to end up with large defects of the surface or naked bone even without periosteum. In cholesteatomata either healthy mucosa is available to spread over the defect or we must provide a grafting of a suitable mucosa. Again, we are in need of every bit of healthy mucosa, for example in the depth of the window niches and around the ossicles and, especially, along the 2 pathways of ventilation through the 2 bottle-necks of aeriation on the way to the antrum. Tynipanoplasty in cholesteatomata is prophylactic surgery. Many cholesteatomas do not penetrate into the antrum but are restricted within the epitympanum and aditus. We must deal with 6 types of cholesteatomata:
Tympanoplasty
433
I The real immigration type of Habermann3 and Bezold4 mainly following severe, necrotic otitis media with large marginal perforations. This is now rare in countries with high medical standards, but is certainly common in others. 2 The primary-papillary cholesteatomata vi hich initially is nearly always a hidden or occult primary cholesteatoma without perforation. 3 The retraction or invagination cholesteatomata.
(The following
2
are iatrogenous types of cholesteatomata.)
4 The recurrent cholesteatoma, an atypic group of invagination cholesteatomata. 5 The residual cholesteatomata deriving from an islet of matrix left behind during surgery. 6 The paralabyrinthine cholesteatomata spreading into the petrous bone and the labyrinthine after penetrating via a fistula. Compared to the high percentage of recurrent and residual cholesteatomata after surgery the latter are rare, but they nearly always end up with the loss of the inner ear function, if surgery is not performed very early. Tympanoplasty is required primarily for elucidation of the different forms of osteitis of the bony capsule of the inner ear and the surrounding petrous bone. For more than 10 years I occupied myself with the pathology on the border line of middle and inner ear in the course of labyrinthitis including monthly functional tests, X-rays and cerebrospinal fluid findings and in correlation with histological series sections. Eventually in a monograph of 1948,5 I was able to close the last gap between inner ear pathology and clinical findings to define exactly every kind of bony destructions and their course : a Acute total osteitis of the inner ear lasting 3 months until spontaneous healing is the most dangerous form. b Independent endosteal osteitis, acute or chronic. c Circumscribed chronic osteitis, so-called fistula, mostly, but not always of the lateral semi-circular canal. d Inner ear and paralabyrinthine cholesteatomata in the petrous bone. e Genuine sequestration of the bony inner ear which is extremely rare.
The antibiotics just coming into the market seduced the otologists to neglect this classification. It is an astonishing fact that only petrous bone cholesteatomata aroused clinical interest anew. These can penetrate deeply with or without the typical roots and can even spread via a small defect through the cortex on the floor of the middle cranial fossa. Furthermore, they are the only consequences of ear inflammation which can never heal spontaneously. They may remain uninfected for long periods of time. That is why antibiotics in the case of the cholesteatomata can prevent diffuse labyrinthitis. Despite large defects of the bony capsule inner ear function persists. Once X-ray shows the first findings of an early inner ear or petrous bone cholesteatomata it is too late to save function, and partial resection of the inner ear is unavoidable. This is why I returned to the view that we must see the spongiotic bone in front and behind the anterior semicircular canal as the ‘points of danger’. Looking at choles-
431
HORST L . W U L L S T E I N
teatomata this way it is obvious that the so-called recurrent and residual ones will show up carlier, the paralabyrinthine much later. Paralabyrinthine cholesteatomata grow slowly and in a silent manner. To reconstruct the middle ear regardless of mucopurulent infection or cholesteatomata in one stage, or with the sound pressure transformation in a second stage, demands a knowledge of the extent of the disease without opening more of the middle ear than necessary. The findings in the mesotympanum even with X-ray are insufficient for this purpose. X-ray cannot differentiate between a wide healthy antrum and a large cholesteatoma; a small perforation makes it impossible to envisage the middle ear. T o avoid the open cavity, in 1953 I introduced control holes: one via the meatus into the aditus to check the passage where infection must go through on the way to the antrum and mastoid (the so-called aditus control), the other one via a mastoidectomy and the facial-chorda-angle into the sinus tympani and the facial recess with a view directly on the round window membrane (the so-called round window control). They both proved not to be sufficient in every case.6 The surgical methods to avoid the open cavity in nearly every case can be grouped in a sequence sacrificing more or less of the bony walls.
Group I Endaural radical mastoidectomy with preservation of some kind of bony bridge or pillar to stretch over soft tissue membranes as new walls. Group 2 Posterior tynipanotomy, intact canal wall technique through the cortex of the mastoid to the antrum and via the facial-chorda-angle in the sinus tympani and facial recess (following in the steps of the posterior control combined with the so-called atticotomy). Group 3 The same large transmastoidal access also, but combined with temporary resection and reimplantation of the posterior bony canal wall. The latest version of this technique is to saw out the posterior wall along the roof of the bony meatus, thus exposing middle ear and mastoid very extensively in each case and refixing the complete bony posterior and superior wall very solidly in a slot. Group 4 Suprameatal access-osteoplastic epitympanotomy directly attacks the main focus in the epitympanum and surgery is expanded only so far as really necessary with immediate reconstruction of the bony wall.
A great number of surgeons strongly advocate group 2 , only some of them have the great skill and perseverance for long-lasting good results in one stage. Two kinds of disappointing outcomes became known as recurrent and residual cholesteatomata. The reason why the z are sequences of the method can be explained : I The so-called closed technique leaves the posterior bony wall intact as far as the external meatus is concerned, but it destroys the posterior mesotympanum completely. Therefore the air no longer ventilates through the inferior ventilation route via the bottle neck of the posterior isthmus tympani into the epitympanum and antrum. Instead it falls directly in the
Tympanoplasty
435
mastoid cavity and does not act as counter pressure against the tympanic membrane thus causing a so-called retraction or invagination cholesteatoma. In surgery complete safe closure for gas or fluid can only be accomplished by solid tissue growth, not by any insertion of alloplastic material. z The reports on the findings of the residual cholesteatomata tells us that they are not of the epitympanal and paralabyrinthine type of cholesteatomata. The majority are found in the mesotympanum. Even the combination of the 2 approaches from behind and via the meatus does not guarantee the certainty necessary to detect every small islet of matrix in the area of the hidden bony niches and the interossicular folds. In our opinion the best surgical method in cases of chronic otitis media should make it possible : a To attack the main focus from the side of its origin, not from behind, to expose it at first directly and to study in detail the course of development. b To expose the area involved completely but not further than necessary, maybe the epitympanum only together with the mesohypotympanum, maybe on the contrary combined with the whole extent of the mastoid. c On the other hand not to expose any area of the pneumatic system clothed with healthy or nearly healthy mucosa as is true in a very high percentage for the antrum and mastoid. d To regain the normal ventilation routes in the middle ear, the upper and especially the lower one-which represent the decisive elements of function of the tympanum. The posterior bony wall of the outer meatus as well as that of the sinus tympani has to be left intact. e With this direct view the utmost care can be taken during the dissection to preserve every bit of mucosa and to create a situation for it to heal and to normalize. A wide access makes it easier and safer to reconstruct the sound pressure transformer at the same time. Above all, the search for the pathology and, especially, for every islet of matrix predominates, With these facts in mind it seems that the methods of Feldmann’ and S. R. Wullstein2 offer the best chance to get rid of the disease as thoroughly as possible in one stage. The latter is the only one which can be ‘made to measure’ to adapt to the pathology and does not need access through the mastoid and so that mucosa is not destroyed unnecessarily. References I
2
3 4 5
6
FELDMANN H. (1977) Eine Stichsage fur die Mikrochirurgie, neue Moglichkeiten zu osteoplastischen Eingriffen am Ohr und den Nebenhohlen. Archiv fur Ohren-Nasen und Kehlkopfheilkunde 2 1 6 , ~ . WULLSTEIN S.R. (1973) Die osteoplastische Epitympanotomie und die Pathologie des Mittelohres. I . Teil das operative Vorgehen. Zeitschr$t f i r Laryngologie, Rhinologie Otologie 52, 34. HABERMANN J. (1889) Zur Entstehung des Cholesteatoms des Mittelohres. Archiv Ohrenheilkunde 27,42. BEZOLD F. (1891) Ober das Cholesteatom des Mittelohres. Zeitschrift Ohrenheilkunde 21, 252. WULLSTEIN H.L. (1948) Die Klinik der Labyrinthitis und Paralabyrinthitis auf Grvnd des Rontgenbef undes. George Thieme, Stuttgart. WULLSTEIN H.L. (1952) Die Eingriffe zur Gehozerbesserung. Abschnitt in Uffenorde: Anzeige und Ausfuhrung der Eingriffe an Ohr, Nase und Hals, 2. Aufl. George Thieme, Stuttgart.
