Ann Otol8S: 1976
LABYRINTHINE FISTULA AND TYMPANOPLASTY
J.
SZPUNAR,
M.D.
KRAKOW, POLAND
SUMMARY - Three interdependent problems have to be solved by a surgeon in each case of middle ear cholesteatoma with a fistula of the horizontal canal: 1) Whether. the matrix can be safely removed from fistula or should be left in place; 2) if the matrix is removed, whether the fistula should be covered or not and, in the positive case, by which kind of graft; and 3) whether closed or open tympanoplasty should be performed. In well selected cases the matrix can be safely removed from the fistula and some technique of closed tympanoplasty used. Suitable for this type of surgery are cases of superficial fistula of the horizontal canal, with preservation of the endosteal membrane, where complete removal of the matrix from the tympanic cavity is possible. Very poor hearing and obvious middle ear infection are apparent contraindications. Furthermore, this type of surgery should not be performed on a better hearing ear. If any difficuty in removal of the matrix from the fistula is encountered, the matrix should be left in place. Fistula cases which do not fulfill these criteria should be treated either by open tympanoplasty or by modified radical mastoidectomy, leaving the matrix on the fistula. A small series of five consecutive fistula cases treated by closed tympanoplasty, using intact wall technique or reconstruction of the bony canal wall, with removal of the matrix from the fistula, leaving it bare, is reported after a follow up of three to six years. The results indicate that, in selected fistula cases, this type of surgery seems to bring favorable late hearing results and to create good conditions for closure of the fistula, apparently not presenting any risk to the inner ear.
The incidence of labyrinthine fistulae in cases of chronic otitis media does not seem to have changed markedly over the years. Nylen! found a fistula in 7.4% of all operated cases; Abramson et al,2 in 7.1%; and Gacek," in 8.3% of cases. According to Troczyfiska," the incidence of labyrinthine fistulae has not decreased in the antibiotic era. On the other hand, the number of patients coming for treatment with clinical symptoms and evidencing localized inflammation of labyrinthine contents in the presence of fistula, has markedly dropped. Nowadays, a labyrinthine fistula is often rather accidentally found during an operation for attic cholesteatoma. Bandtlow" elicited preoperatively a positive fistula sign in only 50% of his cases with a fistula found at operation, and Palva" only in 40%. Surgical treatment of labyrinthine fistulae has considerably varied in the
past, depending on the operative technique and experience of surgeons. Until the 1950's the general attitude of surgeons towards the fistula and its surroundings was very cautious and conservative. The cholesteatoma matrix covering fistula was, as a rule, left in place at a radical operation. It should be mentioned, however, that as early as 1923 Nylen! experimented in making the fistula clearly visible by using binocular magnification of 8-25 times. In a good percentage of operated cases, he removed all pathology from the fistula, leaving it uncovered. In his report he did not mention any untoward effects of these maneuvers. Hinsberg? reported careful cleaning of the fistula region and expressed doubts whether the generally accepted attitude of leaving granulations and the cholesteatoma matrix on the fistula was always correct. Improvement in the operative tech-
From the Department of Otolaryngology, Medical Academy, Krakow, Poland.
291
Downloaded from aor.sagepub.com at Bobst Library, New York University on May 27, 2015
292
t.
SZPUNAR
nique, introduction of antibiotics and more experience in fenestration operation gained by many surgeons, led to a substantial change in surgical management of labyrinthine fistulae in cases of chronic otitis media. In the 1950's several surgeonsvP introduced new methods of management of fistulae. These consisted of careful but consequent surgical cleaning of fistula and its surroundings from all pathologic tissue and covering the bare fistula with various grafts, e.g. skin, mucosa," fascia, vein etc. Utech'" first reported closing fistulae with a small piece of bone, to be covered with skin. Introduction of principles of tympanoplasty did not initially change the attitude of otosurgeons towards labyrinthine fistula much. For a long time the cases with labyrinthine fistulae were generally not considered suitable for reconstructive surgery. Still, GarciaIbanez in 195214 reported his method of dealing with the fistula, consisting of sound protection of the round window and covering the fistula with a skin graft. Later on, a similar method was introduced by Wullstein'" as type V tympanoplasty. Bandtlow in 19615 published a report of his experience with application of tympanoplastic methods in the presence of labyrinthine fistulae in a series of 60 cases and reported favorable functional results. Today, the mere presence of labyrinthine fistulae is ~enerally not considered a contraindication to an appropriate type of reconstruction of the conductive system of the middle ear. 16 Introduction of closed tympanoplasty and of intact wall technique has markedly changed our views on reconstruction of the middle ear in different pathologic conditions. Since a large number of otosurgeons are almost exclusively using methods of closed tympanoplasty, it appears natural that they have tried to apply these techniques also to cases with labyrinthine fistulae. Application of closed tympanoplasty techniques in cases with labyrinthine fistulae has marked advantages. In this way the fistula is completely separated from
noxious external influences and, in the absence of a cavity, a source of possible recurring infections is eliminated. LABYRINTHINE FISTULA IN CHRONIC OTITIS
A fistula arises, in the overwhelming majority of cases, in the presence of cholesteatoma in the attic region. The osteolytic effect of the cholesteatoma membrane is due to a combination of pressure and a biochemical mechanism. Weare only concerned with spontaneous fistulae of a semicircular canal, apparently free from inflammatory changes in the labyrinth. The most frequent location of such a fistula is on the convex surface of the horizontal canal. Fistulae in other locations, especially those in the window region, shall not be taken into consideration as they raise different problems and require different surgical measures. Fistulae of the horizontal canal may be divided into two types: superficial, and deep. With superficial fistulae, the condition of the endosteal membrane determines the risk involved in separation of the matrix. When the endosteal membrane is fully preserved it separates the perilymphatic space from overlying cholesteatoma matrix. Therefore the matrix can be peeled off the fistula quite easily. Such a fistula much resembles a surgically produced fistula of the fenestration operation." Edwards'" calls this type of fistula "natural fenestration." When the endosteal membrane is partially destroyed by the pathologic process, adherences of the matrix to the membranous canal form. In this instance attempts at separation of the matrix from the fistula usually involve considerable risk of injuring the membranous labyrinth. Deep fistulae are always accompanied by partial damage of the membranous canal. Often, concomitant osteitis or partial destruction of the surrounding bone are found. In Gacek's opinion," in fistulae smaller than 2 mm diameter, the cholesteatoma
Downloaded from aor.sagepub.com at Bobst Library, New York University on May 27, 2015
LABYRINTHINE FISTULA
matrix is supported by the bony margins of the fistula and so remains separated from the underlying endosteum and the membranous canal by connective tissue. In this instance, the matrix lends itself to safe removal from the fistula. On the other hand, when a fistula is larger than 2 mm, the matrix usually adheres to the membranous canal because there is less marginal bone around the fistula to support the cholesteatoma lining. In the latter case it is more risky to attempt removal of the matrix from the membranous canal. In our experience, dimensions of a fistula are not always a factor in deciding as to the safety of removing the matrix from the fistula. We came across some cases where the matrix lay quite loosely over a fistula of a considerable size and could have been easily removed.
Covering the Fistula. It follows from animal experiments that application of a skin flap on a labyrinthine fistula has an inhibiting influence on osteogenesis in the bony edges of the fistula. 19 It appears very probable that leaving the matrix over a fistula has a similar influence. In Shambaugh's opinion.!" a fistula with matrix remaining tends to remain open permanently, due to the osteogenic-inhibiting effect of the epithermal covering. Covering a spontaneous fistula laid bare after removal of the matrix with a mesenchymal graft, usually a piece of fascia, is now a widely accepted method. The graft initially serves as a layer isolating the labyrinth from infection and noxious external influences, and later forms a membrane covering the fistula. It is generally believed that any erosions or defects in the otic capsule, occurring in the course of chronic otitis, heal mainly by fibrous union.t? But, for many reasons, in consideration of audiologic results, bony closure of fistula is considered by many authors13.20.21.23 to be an ideal eventuality. These authors assume that covering the fistula with an appropriately shaped bone graft may, in some circumstances, promote bony closure of fistula. With
293
the same aim Herrmann" advised putting some bone dust in the fistula region. In our experience, under conditions of closed tympanoplasty leaving the fistula bare, what amounts to healing under blood clot, is a quite safe method. At the same time it seems to lead to rigid closure of the fistula. In our five cases thus operated on, with follow up of three to six years. the ultimate fistula test was completely negative in four cases and doubtful in one patient.
Closed Tympanoplasty and the Labyrinthine Fistula. In all closed techniques the area of the horizontal canal is separated from the external canal by preserved or reconstructed bony canal wall. Methods of isolation of the fistula from noxious external influences including infection, necessarily used in open techniques, are here no longer required. When applying any closed tympanoplastic technique in the presence of a labyrinthine fistula, removal of all pathology, in particular of every trace of the cholesteatoma matrix, is a necessity. Sheeh y22 uses intact canal wall technique in cases with fistula. but leaves the matrix in situ over the fistula to remove it at a second operation when the ear is well healed. In his opinion. this two-stage technique has lowered the incidence of marked postoperative sensorineural hearing impairment or loss. In some cholesteatoma cases with fistula the intact canal wall technique may present technical difficulties when performing delicate maneuvers around the fistula, the angle of vision being not the most convenient one. This may sometimes lead to unfavorable hearing results. Thus, in some of these cases it might be safer to oartially remove the posterio-superior bony canal wall and reconstruct it with bone or cartilage at the end of the operation.
Influence of Persisting LabfJrinthine Fistula on Hearing Results after Tympanoplastu. In the experience of some otologists,23.24 hearing results obtained after apparently successful open tympanoplasty performed in the presence
Downloaded from aor.sagepub.com at Bobst Library, New York University on May 27, 2015
I:':)
LABYRINTHINE FISTULA AND TYMPANOPLASTY
J.
SZPUNAR,
M.D.
KRAKOW, POLAND
SUMMARY - Three interdependent problems have to be solved by a surgeon in each case of middle ear cholesteatoma with a fistula of the horizontal canal: 1) Whether. the matrix can be safely removed from fistula or should be left in place; 2) if the matrix is removed, whether the fistula should be covered or not and, in the positive case, by which kind of graft; and 3) whether closed or open tympanoplasty should be performed. In well selected cases the matrix can be safely removed from the fistula and some technique of closed tympanoplasty used. Suitable for this type of surgery are cases of superficial fistula of the horizontal canal, with preservation of the endosteal membrane, where complete removal of the matrix from the tympanic cavity is possible. Very poor hearing and obvious middle ear infection are apparent contraindications. Furthermore, this type of surgery should not be performed on a better hearing ear. If any difficuty in removal of the matrix from the fistula is encountered, the matrix should be left in place. Fistula cases which do not fulfill these criteria should be treated either by open tympanoplasty or by modified radical mastoidectomy, leaving the matrix on the fistula. A small series of five consecutive fistula cases treated by closed tympanoplasty, using intact wall technique or reconstruction of the bony canal wall, with removal of the matrix from the fistula, leaving it bare, is reported after a follow up of three to six years. The results indicate that, in selected fistula cases, this type of surgery seems to bring favorable late hearing results and to create good conditions for closure of the fistula, apparently not presenting any risk to the inner ear.
The incidence of labyrinthine fistulae in cases of chronic otitis media does not seem to have changed markedly over the years. Nylen! found a fistula in 7.4% of all operated cases; Abramson et al,2 in 7.1%; and Gacek," in 8.3% of cases. According to Troczyfiska," the incidence of labyrinthine fistulae has not decreased in the antibiotic era. On the other hand, the number of patients coming for treatment with clinical symptoms and evidencing localized inflammation of labyrinthine contents in the presence of fistula, has markedly dropped. Nowadays, a labyrinthine fistula is often rather accidentally found during an operation for attic cholesteatoma. Bandtlow" elicited preoperatively a positive fistula sign in only 50% of his cases with a fistula found at operation, and Palva" only in 40%. Surgical treatment of labyrinthine fistulae has considerably varied in the
past, depending on the operative technique and experience of surgeons. Until the 1950's the general attitude of surgeons towards the fistula and its surroundings was very cautious and conservative. The cholesteatoma matrix covering fistula was, as a rule, left in place at a radical operation. It should be mentioned, however, that as early as 1923 Nylen! experimented in making the fistula clearly visible by using binocular magnification of 8-25 times. In a good percentage of operated cases, he removed all pathology from the fistula, leaving it uncovered. In his report he did not mention any untoward effects of these maneuvers. Hinsberg? reported careful cleaning of the fistula region and expressed doubts whether the generally accepted attitude of leaving granulations and the cholesteatoma matrix on the fistula was always correct. Improvement in the operative tech-
From the Department of Otolaryngology, Medical Academy, Krakow, Poland.
291
Downloaded from aor.sagepub.com at Bobst Library, New York University on May 27, 2015
292
t.
SZPUNAR
nique, introduction of antibiotics and more experience in fenestration operation gained by many surgeons, led to a substantial change in surgical management of labyrinthine fistulae in cases of chronic otitis media. In the 1950's several surgeonsvP introduced new methods of management of fistulae. These consisted of careful but consequent surgical cleaning of fistula and its surroundings from all pathologic tissue and covering the bare fistula with various grafts, e.g. skin, mucosa," fascia, vein etc. Utech'" first reported closing fistulae with a small piece of bone, to be covered with skin. Introduction of principles of tympanoplasty did not initially change the attitude of otosurgeons towards labyrinthine fistula much. For a long time the cases with labyrinthine fistulae were generally not considered suitable for reconstructive surgery. Still, GarciaIbanez in 195214 reported his method of dealing with the fistula, consisting of sound protection of the round window and covering the fistula with a skin graft. Later on, a similar method was introduced by Wullstein'" as type V tympanoplasty. Bandtlow in 19615 published a report of his experience with application of tympanoplastic methods in the presence of labyrinthine fistulae in a series of 60 cases and reported favorable functional results. Today, the mere presence of labyrinthine fistulae is ~enerally not considered a contraindication to an appropriate type of reconstruction of the conductive system of the middle ear. 16 Introduction of closed tympanoplasty and of intact wall technique has markedly changed our views on reconstruction of the middle ear in different pathologic conditions. Since a large number of otosurgeons are almost exclusively using methods of closed tympanoplasty, it appears natural that they have tried to apply these techniques also to cases with labyrinthine fistulae. Application of closed tympanoplasty techniques in cases with labyrinthine fistulae has marked advantages. In this way the fistula is completely separated from
noxious external influences and, in the absence of a cavity, a source of possible recurring infections is eliminated. LABYRINTHINE FISTULA IN CHRONIC OTITIS
A fistula arises, in the overwhelming majority of cases, in the presence of cholesteatoma in the attic region. The osteolytic effect of the cholesteatoma membrane is due to a combination of pressure and a biochemical mechanism. Weare only concerned with spontaneous fistulae of a semicircular canal, apparently free from inflammatory changes in the labyrinth. The most frequent location of such a fistula is on the convex surface of the horizontal canal. Fistulae in other locations, especially those in the window region, shall not be taken into consideration as they raise different problems and require different surgical measures. Fistulae of the horizontal canal may be divided into two types: superficial, and deep. With superficial fistulae, the condition of the endosteal membrane determines the risk involved in separation of the matrix. When the endosteal membrane is fully preserved it separates the perilymphatic space from overlying cholesteatoma matrix. Therefore the matrix can be peeled off the fistula quite easily. Such a fistula much resembles a surgically produced fistula of the fenestration operation." Edwards'" calls this type of fistula "natural fenestration." When the endosteal membrane is partially destroyed by the pathologic process, adherences of the matrix to the membranous canal form. In this instance attempts at separation of the matrix from the fistula usually involve considerable risk of injuring the membranous labyrinth. Deep fistulae are always accompanied by partial damage of the membranous canal. Often, concomitant osteitis or partial destruction of the surrounding bone are found. In Gacek's opinion," in fistulae smaller than 2 mm diameter, the cholesteatoma
Downloaded from aor.sagepub.com at Bobst Library, New York University on May 27, 2015
LABYRINTHINE FISTULA
matrix is supported by the bony margins of the fistula and so remains separated from the underlying endosteum and the membranous canal by connective tissue. In this instance, the matrix lends itself to safe removal from the fistula. On the other hand, when a fistula is larger than 2 mm, the matrix usually adheres to the membranous canal because there is less marginal bone around the fistula to support the cholesteatoma lining. In the latter case it is more risky to attempt removal of the matrix from the membranous canal. In our experience, dimensions of a fistula are not always a factor in deciding as to the safety of removing the matrix from the fistula. We came across some cases where the matrix lay quite loosely over a fistula of a considerable size and could have been easily removed.
Covering the Fistula. It follows from animal experiments that application of a skin flap on a labyrinthine fistula has an inhibiting influence on osteogenesis in the bony edges of the fistula. 19 It appears very probable that leaving the matrix over a fistula has a similar influence. In Shambaugh's opinion.!" a fistula with matrix remaining tends to remain open permanently, due to the osteogenic-inhibiting effect of the epithermal covering. Covering a spontaneous fistula laid bare after removal of the matrix with a mesenchymal graft, usually a piece of fascia, is now a widely accepted method. The graft initially serves as a layer isolating the labyrinth from infection and noxious external influences, and later forms a membrane covering the fistula. It is generally believed that any erosions or defects in the otic capsule, occurring in the course of chronic otitis, heal mainly by fibrous union.t? But, for many reasons, in consideration of audiologic results, bony closure of fistula is considered by many authors13.20.21.23 to be an ideal eventuality. These authors assume that covering the fistula with an appropriately shaped bone graft may, in some circumstances, promote bony closure of fistula. With
293
the same aim Herrmann" advised putting some bone dust in the fistula region. In our experience, under conditions of closed tympanoplasty leaving the fistula bare, what amounts to healing under blood clot, is a quite safe method. At the same time it seems to lead to rigid closure of the fistula. In our five cases thus operated on, with follow up of three to six years. the ultimate fistula test was completely negative in four cases and doubtful in one patient.
Closed Tympanoplasty and the Labyrinthine Fistula. In all closed techniques the area of the horizontal canal is separated from the external canal by preserved or reconstructed bony canal wall. Methods of isolation of the fistula from noxious external influences including infection, necessarily used in open techniques, are here no longer required. When applying any closed tympanoplastic technique in the presence of a labyrinthine fistula, removal of all pathology, in particular of every trace of the cholesteatoma matrix, is a necessity. Sheeh y22 uses intact canal wall technique in cases with fistula. but leaves the matrix in situ over the fistula to remove it at a second operation when the ear is well healed. In his opinion. this two-stage technique has lowered the incidence of marked postoperative sensorineural hearing impairment or loss. In some cholesteatoma cases with fistula the intact canal wall technique may present technical difficulties when performing delicate maneuvers around the fistula, the angle of vision being not the most convenient one. This may sometimes lead to unfavorable hearing results. Thus, in some of these cases it might be safer to oartially remove the posterio-superior bony canal wall and reconstruct it with bone or cartilage at the end of the operation.
Influence of Persisting LabfJrinthine Fistula on Hearing Results after Tympanoplastu. In the experience of some otologists,23.24 hearing results obtained after apparently successful open tympanoplasty performed in the presence
Downloaded from aor.sagepub.com at Bobst Library, New York University on May 27, 2015
I:':)
