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Revision of endolymphatic sac surgery for recurrent Meniere's disease
Otolaryngol Clin N Am 35 (2002) 607–619
Revision of endolymphatic sac surgery for recurrent Meniere’s disease Michael M. Paparella, MD* Minnesota Ear, Head, and Neck Clinic, Suite 200, 701 25th Avenue South, Minneapolis, MN 55454, USA
Although endolymphatic hydrops can be experimentally induced in animals, Meniere’s disease as a clinical entity can occur only in humans. Understanding pathogenesis, the major theme of this publication, can result from studying the natural history of Meniere’s disease. If it were possible, however, to study the evolution of the pathogenesis of Meniere’s disease, then intercede with treatment to counteract that pathogenesis and then, in delayed fashion, to observe visually the pathogenesis and pathologic conditions taking place after surgery and then, once again, to treat and counteract it so as to dramatically ameliorate severe cochlear and vestibular symptoms, would this not represent a marvelous opportunity to understand the pathogenesis of Meniere’s disease? Such an opportunity exists in surgical revisions for recurrent Meniere’s disease after a successful initial result of endolymphatic sac enhancement (ESE), usually after good results have been retained over a period of years. In addition to avoiding destructive procedures, revision of ESE has restored health to many patients. Most important for the purposes here, however, is that these procedures and findings, which are briefly described, have provided the best opportunity for the author to understand and observe the pathogenesis of Meniere’s disease. Management by medical and psychologic support is the first requirement for treatment of patients with progressive Meniere’s disease who have either intractable recurrent vertigo, deafness, or both. Intractability that persists despite medical treatment may require considering surgical enhancement of the endolymphatic sac, a reasonably safe otologic procedure that also provides opportunity to reverse the conditions that favor the pathogenic conditions (such as malabsorption of endolymph) that are the likely cause of hydrops. The author tries to avoid labyrinthectomy because these patients may, in the future, be able to use a cochlear implant, and this is important * E-mail address: [email protected] (M.M. Paparella). 0030-6665/02/$ - see front matter Ó 2002, Elsevier Science (USA). All rights reserved. PII: S 0 0 3 0 - 6 6 6 5 ( 0 2 ) 0 0 0 3 2 - 4
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because some patients with Meniere’s disease can be susceptible to complete bilateral deafness. Some patients may have excellent results from ESE that may last 3 or 4 years, but then clinical symptoms such as vertigo or deafness can recur. The option of surgically revising their ESE is discussed with these patients, and they are also offered sectioning of the vestibular nerve when the original ESE has failed; however, only one of the author’s patients has required vestibular nerve section. In those who choose the revisional surgery, intraoperative findings, including extrasaccular fibrosis, osteoneogenesis, and aditus block are commonly seen. These symptoms mainly diminish, sometimes dramatically, after the revisional surgery. Those patients who choose revisional surgery obtain diminishment of their recurrent symptoms, but the surgeon also gains intraoperative insights that constitute a unique opportunity to study the pathogenesis of Meniere’s disease, something only observable in humans in vivo. After the 4-year period from July 1982 to July 1986, the author and colleague Hamed Sajjadi [1] assessed all their cases of revision of ESE that had had at least 2 years of follow-up. In this period, 26 ESEs were revised, an incidence of 7%. Because many of the original ESEs had been done years earlier (before 1982), however, the overall percentage rate for the period studied was only 4%. All patients had initially enjoyed good results from the ESE that diminished their symptoms, but the symptoms then gradually redeveloped in the following months and years. The asymptomatic period for these 26 patients ranged from 6 months to 11 years (average 2.6 years). Two patients had suddenly encountered recurrence of vertigo and hearing loss, one 2.5 years after the ESE and the other 3.5 years after ESE. One of the 26 patients had two revisions of the original ESE. Another had bilateral Meniere’s disease requiring one revision on the left ear and three revisions on the right ear (at the patient’s request) [1]. The patients’ reasons for requesting revisional surgery included both recurrent vertigo and hearing loss (in 22 patients) and hearing loss alone (in 4 patients). Two other patients received revisions of an ESE during this period because of immediate postoperative infection of the wound, but these two patients (who exhibited copious granulation tissue and aditus block in the mastoid cavity) are not included among the 26 revisions discussed here. In the included 26 patients, intraoperative findings in every case included primarily osteoneogenesis and scar tissue near the sac. Formation of the new bone was mostly from the adjacent region of the lateral sinus and from within the infralabyrinthine cell tract. In some of the initial ESEs, there had been insufficiently wide decompression and removal of bone [1]. The copious scar tissue seen in some was contiguous with the inferior margin of the wound and also near the mastoid tip. This scar tissue was always extrasaccular, not invading the lumen of the endolymphatic sac. This may have been due to the authors’ method of making a small opening in the sac below the solid bony angle, although the authors also revised some
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procedures that had been performed by other surgeons who did open the sac to the mastoid cavity. In the initial procedure in six patients who later developed a lot of scar tissue, grafting to protect the sac had been done using temporalis fascia, as was done routinely in those years. The authors discontinued this grafting in 1983 because of these findings seen upon revision [1]. When Silastic (Invotec International Inc., Jacksonville, FL) was removed from the sac, in every case it was yellowed, which suggests transudation of extracellular fluid. Epithelium in the lumen was shiny and intact. The aditus ad antrum was completely obstructed in 2 patients and partially obstructed in 11 patients who had formation of more tissue in the mastoid cavity. A bony shelf (operculum or anatomic variant) was seen on the subdural side in two patients; it obviated decompression at that site [1]. Four patients elected revision because of recurrence of hearing loss only (without vertigo); in three patients, hearing improved (average increase in discrimination, 24%; average increase in speech reception threshold, 16 dB), and in one patient, it stayed the same (Table 1). Surgery was done for recurrence of hearing loss and vertigo in the remaining 22 patients; 13 subsequently gained improved hearing and 9 stayed the same. Improvements in hearing averaged a 20% increase in discrimination and an 18 dB gain in speech reception threshold. Hearing loss and vertigo occurred suddenly, years after the initial procedure, in two patients in whom the authors then did an exploratory tympanotomy with endolymphatic sac revision because of the possibility of sudden deafness with perilymphatic fistula. Perilymphatic drainage was seen at the round window in one patient; in the other, perilymphatic drainage was strongly suggested, so the authors grafted the round windows. Both patients achieved improved hearing subsequent to revision. Vertigo was significantly improved in all but 1 of the 22 with recurrent hearing loss and vertigo, being eliminated in 12 and substantially controlled in 9. One patient required sectioning of the vestibular nerve [1]. Case reports Case 1 Classic Meniere’s disease with hearing loss and vertigo had been seen in this 29-year-old man for 8 years. After ESE, he had improvement of hearing, Table 1 Summary of results of revision of endolymphatic sac enhancement in 26 patients
Number of patients Hearing improved after revision Hearing the same after revision Vertigo eliminated by revision Vertigo controlled (improved) Vertigo the same after revision
Vertigo and deafness
Deafness
22 13 9 12 9 1
4 3 1
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elimination of vertigo, and diminution of other symptoms. Two and a half years after the initial ESE, his vertigo was still controlled but he had developed hearing loss and pressure in the operated ear. After discussion of the pros and cons of sac enhancement, revisional surgery was undertaken and, since then, he has improved hearing and his vertigo continues to be controlled (Fig. 1). Case 2 Intractable Meniere’s disease for 7 years was characterized in the left ear of this 36-year-old man by frequent incapacitating episodic vertigo, fluctuating sensorineural deafness, pressure, tinnitus, and inability to tolerate loudness. Fig. 2A shows his preoperative audiogram; Fig. 2B shows his postoperative audiogram. After the sac enhancement, hearing in the left ear improved in subsequent years, and the patient was free of vertigo for 4 years, when he developed severe symptoms including incapacitating vertigo, pressure, and ‘‘deafness’’ confirmed by shouting and testing using tuning forks while the other ear was masked. Serial audiograms were done by two audiologists approximately 5, 6, and 7 months into recurrence (Fig. 2C, D, and E). The patient considered both ESE and nerve section, and selected ESE.
Fig. 1. Audiographic findings in Case 1 are shown (A) before the initial ESE. After surgery, hearing improved in the right ear and vertigo ceased. Then, in 1982, symptoms of deafness recurred (B). (C) Audiogram shows that hearing was restored after the revisional surgery (results shown 1 year postoperatively). (From Paparella MM, Sajjadi H. Endolymphatic sac revision for recurrent Meniere’s disease. Am J Otol 1988;9(6):441–7; with permission.)
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Fig. 1 (continued )
Intraoperative findings included a characteristically reduced Trautmann’s triangle with much new bone and scar tissue growing into the region near the sac. The authors aggressively enlarged the infralabyrinthine bony cell tract, removed bone and scar tissue, widely decompressed the lateral sinus, and revised the sac enhancement. This patient remains free of vertigo and other symptoms, with dramatic return of improved hearing equaling or
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Fig. 2. (A) Audiogram for Case 2 obtained before initial ESE. (B) Postoperative audiogram showing retained hearing. Vertigo was gone. (C, D, E) Four years later, the patient developed recurrent incapacitating symptoms including deafness and vertigo. Recurrent deafness was repeatedly confirmed over a series of 3 months in the second quarter of the fourth year following initial ESE; speech discrimination was 0 each time. Four and three fourths years after initial ESE, revisional surgery was done. (F) Ten months postoperatively, the results after revision returned to or exceeded the levels before the original ESE, and vestibular and other symptoms remained absent. (From Paparella MM, Sajjadi H. Endolymphatic sac revision for recurrent Meniere’s disease. Am J Otol 1988;9(6):441–7; with permission.)
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Fig. 2 (continued )
bettering the initial preoperative level before the first ESE; follow-up audiogram taken 9 months postoperatively demonstrates these results (Fig. 2F). Although results in another two patients in the study were not this dramatic, they too had hearing restored from ‘‘deafness’’ to useful hearing, after the revisional surgery.
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Fig. 2 (continued )
Case 3 Bilateral incapacitating intractable Meniere’s disease was seen in this 31-year-old woman, a supervisory nurse who complained of recurrent vertigo and hearing loss in one ear. Her left ear received the first ESE; 1 year later, the right ear received an ESE. Three years later, the left ear received revisional surgery. Revisions on the right ear were done at 1 year, 6.5 years,
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and 8.5 years following initial ESE. Because this patient was well read about Meniere’s disease and had experienced relief of symptoms following revisional surgery, she continued to elect sac revisions even though nerve section was recommended. Each time she achieved elimination of vertigo and pressure and felt well, but the symptoms recurred later. She has remained well since her last procedure (Fig. 3). In our total series of cases, only 5% have needed a second revision; this patient’s four revisions are unique.
These observations prompted modifications of our procedure As described elsewhere [2], because of these observations made at revisions of ESEs, the author’s clinic now treats the wound differently. First, because several cases previously had problems chiefly with postoperative infection of the wound, an elliptic incision at least 1 inch behind the postauricular crease is now made, ending posterior to the mastoid tip inferiorly so that the line of incision does not cross the open mastoid cavity. The skin is elevated alone or with periosteum attached. The skin, which often contains a thick dermis, is now thinned with plastic scissors to discourage fibroblastic invasion from this site into a hypoplastic mastoid. At the end of the procedure, the debris is meticulously removed from the wound and all subcutaneous bleeders are controlled to prevent blood entering the mastoid, which can promote scarring and formation of granulation tissue. The wound is carefully closed in layers.
Fig. 3. Postoperative audiogram for Case 3 after revisional surgery. (From Paparella MM, Sajjadi H. Endolymphatic sac revision for recurrent Meniere’s disease. Am J Otol 1988;9(6): 441–7; with permission.)
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Second, a complete mastoidectomy is done, with wide exposure. The sac is usually found anterior and inferior to the posteroinferior semicircular canal. The lateral sinus (usually abnormally located medially and anteriorly) is widely exposed and the bone over it is removed. In some revisions, it was noticed that the lateral sinus had not been as widely decompressed initially as it should have been so that bone remaining in a remote region would not allow effective decompression of the dura and contiguous sac. Because bone from the lateral sinus can create osteoneogenesis growing toward the sac, a meticulous effort is made not to leave bone on the lateral sinus. Third, modifications were made to open widely the aditus contiguous with the suprapyramidal or facial recess not only to expose the incus and its fossa incudis as an important landmark but also to encourage good aeration between middle ear and mastoid cavity. Fourth, to ensure wide decompression, bone is removed widely over Trautmann’s triangle and over the entire lateral sinus to decompress all available lateral sinus and dura of the posterior cranial fossa that contains the sac, in a general and exaggerated way. This decompression is enhanced by using coiled Silastic spacers that act as loose springs to separate the tight dura from the bone of the solid angle. Fascia is no longer used to cover the sac, but rather an ‘‘apron’’ of Silastic is used to protect against fibroblastic invasion. A Silastic T-strut (small, medium, or large) is shaped and coiled within the lumen of the sac, and spacers are used to decompress the dura above and below the sac, as much as possible. Opening the sac widely under the solid angle, Silastic spacers are used to contain the environment of the sac to this region rather than letting it possibly extend toward the open mastoid cavity. Fifth, a myringotomy and ventilation tube routinely is placed in the anterior tympanic membrane to promote healing, drainage, and ventilation, to help avoid otitis media (the author has noted, for example, that in a few of these patients, otitis media may be related to flying), and to help aerate the mastoid in an attempt to discourage aditus block syndrome, osteneogenesis, and formation of fibrous tissue in the mastoid during the first postoperative year. Finally, in recent years, it has been observed that saturation and perfusion of the endolymphatic sac with gentamicin during this procedure, including gentamicin exposure to the round window for a 7- to 10-minute period in patients who have a severe hearing loss, has been a helpful clinical adjunct in eliminating vertigo in patients undergoing revision of sac surgery.
Discussion Clinical implications of revisions of ESE It is probable that because patients had already had good primary results from the initial ESE, revisional surgery resulted in decreases in vertigo and
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improvement in hearing that were even better than those from the initial ESE. Years later, iatrogenic osteoneogenesis and formation of scar tissue recreated the pathogenic conditions, and then the correction of these secondary lesions provided an even better chance for beneficial results. At the time of revision, primary findings to be corrected include formation of extrasaccular bone and fibrous tissue, aditus block, tight dura near the sac, and yellowed Silastic within and near the sac. After revisional surgery, resultant hearing has been significantly better (twice as good, increasing at least 15 dB in speech reception threshold and gaining 15% in speech discrimination) in 62% of our patients receiving a revision of ESE; the initial ESE produced significantly better hearing in only 30% to 40%. Dramatic restorations of hearing have been achieved in some patients who received revisions of ESE who went from deafness to useful hearing (see particularly the audiograms for Case 2, Fig. 2A–F). In three of these four patients, recurrent hearing loss that occurred alone improved. Those who had both recurrent vertigo and hearing loss had control or elimination of vertigo in 95% after revisions of ESE, and only one patient to date later had a vestibular nerve section. In the two patients in whom there was sudden recurrence of hearing loss, vertigo, or both after an initially good result of ESE, an associated perilymphatic fistula of the round window was identified and treated. Risks were found to be nonexistent from revisions of ESE in this study, and the results were gratifying. All patients but one continue to do well with this conservative therapy; only one patient required intracranial vestibular nerve section. These results indicate that patients who have good results following sac enhancement procedures but then later develop delayed recurrence of symptoms such as vertigo or hearing loss can be considered for revisional surgery that can even be repeated, if necessary. If vertigo continues as the primary problem, then retrolabyrinthine vestibular nerve section or physical or chemical labyrinthectomy can still be considered, although every effort is made to avoid this because a significant number of patients with Meniere’s disease develop bilateral deafness eventually, and labyrinthectomy will compromise future consideration of a cochlear implant. Since the 1982 to 1986 period reported on in this study, which had a relatively limited number of patients, many other patients have demonstrated similar findings and, in fact, better results may be obtained in revision than those resulting from the initial ESE. Pathogenesis of natural and ‘‘induced’’ Meniere’s disease From observations made in revision of ESE where each patient serves as his or her own control, clinicians can gain insights into the nature, cause, pathogenesis, and treatment of Meniere’s disease. Conditions in these patients provide a unique opportunity to study the natural history of this disease found only in humans in vivo and to make a diagnosis of intractable
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Meniere’s disease and treat it (in this case, with ESE), only to have symptoms recur later after developing conditions can be seen. ESE is designed to reverse conditions that appear to contribute to the fundamental pathogenic process of this disease—the malabsorption of endolymph—and these patients also had good results, typically for a few years after their initial sac enhancement procedures. When they became candidates for revisional surgery, the delayed and gradual rebuilding of those conditions after iatrogenic inducement could be observed intraoperatively. There can be osteoneogenesis, fibrosis, and granulation tissue causing a very tight and constricted dura, Trautmann’s triangle, and saccular region, resulting in obvious pressure or obstruction to this region. When these lesions are corrected and the dura is decompressed or loosened during revisional surgery, most patients once again have elimination or control of symptoms. Most patients who receive ESE benefit for a lifetime, but about 7% of the author’s patients who have had an ESE later have recurrences and require revision, usually many years after an initially good result. These circumstances provide an opportunity to observe the natural history of this disease, diagnose and treat it, observe clinical improvement after treatment (ESE), observe the delayed results of the recreated diseased conditions with all the clinical manifestations, observe those lesions intraoperatively and treat them, and then once again see resolution of clinical symptoms. The findings seen in this process appear to substantiate observations that the natural pathogenesis of Meniere’s disease involves endolymphatic malabsorption from conditions that ESE counteracts. Revisions of ESE counteract and treat pathogenic conditions that may have been induced (or not sufficiently prevented) by the former surgery. During these revisions, an important intraoperative finding is that Silastic removed from the lumen of the sac is yellowed, suggesting the occurrence of extracellular transudation. It can be hypothesized that this yellowing is from spinal fluid (as in shunting procedures draining the endolymphatic sac to the subarachnoid space) or from extracellular transudate creating the environment in the lumen of the sac, and it can be hypothesized that there is an osmotic pump or pull effect in which sodium ions near the formerly treated sac have pulled potassium ions from the opposite end of the endolymphatic duct. The following are hypotheses concerning the mechanisms by which ESE and its revisions might work to counteract pathogenic conditions that are based on the author’s observations intraoperatively in these surgical revisions and also on laboratory and clinical research. Hypothesis concerning decompression Due to pathologic anatomic abnormalities (some of which may be genetic), patients have a tight endolymphatic sac and contiguous dura and, particularly, a medially and anteriorally displaced lateral sinus. This abnormality requires complete simple mastoidectomy, wide removal of
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bone from over Trautmann’s triangle, the lateral sinus, and the area of the infralabyrinthine cell tract, and decompression of the dura from the solid angle. Decompression is enhanced by use of Silastic T-stuts to enlarge the lumen and the use of Silastic spacers to loosen dura from bone above and below the sac. It is hypothesized that decompression is the most important surgical contribution to counteracting the important pathogenic mechanism of obstruction of a tightened, restricted sac and dura. Hypothesis concerning osmotic pull Between the extracellular milieu within and near the sac (high in sodium) and endolymph on the other side of the vestibular aqueduct (high in potassium), there is an osmotic pressure-differential created. The transudate produced in this flow yellows Silastic that was placed in the sac at initial ESE. This environment is made not in the mastoid cavity but rather between bone and dura. Comparatively, Silastic retrieved from the middle ear in hundreds of surgical revisions of tympanoplasty retains its original clear color. Hypothesis concerning passive diffusion of endolymph By providing an enlarged, decompressed saccular lumen and Silastic (alloplastic) T-struts within the lumen, surfaces are provided against which nanoliters of endolymph can move passively. The Silastic may act as a wick exiting the sac to lie under bone, not in the mastoid cavity. Hypothesis concerning altered blood supply When the blood supply around the sac is surgically manipulated, collateral blood supply may be encouraged. This region is isolated by the Silastic ‘‘apron’’ separating the sac from the mastoid cavity to help prevent fibroblastic invasion. ESE or revision of the procedure may also alter immune properties in the sac. References [1] Paparella MM, Sajjadi H. Endolymphatic sac revision for recurrent Meniere’s disease. Am J Otol 1988;9(6):441–7. [2] Paparella MM. Endolymphatic sac procedures. In: Brackmann DE, Shelton C, Arriaga MA, editors. Otologic Surgery. 2nd edition. Philadelphia: W.B. Saunders; 2001. p. 371–84.
Revision of endolymphatic sac surgery for recurrent Meniere’s disease Michael M. Paparella, MD* Minnesota Ear, Head, and Neck Clinic, Suite 200, 701 25th Avenue South, Minneapolis, MN 55454, USA
Although endolymphatic hydrops can be experimentally induced in animals, Meniere’s disease as a clinical entity can occur only in humans. Understanding pathogenesis, the major theme of this publication, can result from studying the natural history of Meniere’s disease. If it were possible, however, to study the evolution of the pathogenesis of Meniere’s disease, then intercede with treatment to counteract that pathogenesis and then, in delayed fashion, to observe visually the pathogenesis and pathologic conditions taking place after surgery and then, once again, to treat and counteract it so as to dramatically ameliorate severe cochlear and vestibular symptoms, would this not represent a marvelous opportunity to understand the pathogenesis of Meniere’s disease? Such an opportunity exists in surgical revisions for recurrent Meniere’s disease after a successful initial result of endolymphatic sac enhancement (ESE), usually after good results have been retained over a period of years. In addition to avoiding destructive procedures, revision of ESE has restored health to many patients. Most important for the purposes here, however, is that these procedures and findings, which are briefly described, have provided the best opportunity for the author to understand and observe the pathogenesis of Meniere’s disease. Management by medical and psychologic support is the first requirement for treatment of patients with progressive Meniere’s disease who have either intractable recurrent vertigo, deafness, or both. Intractability that persists despite medical treatment may require considering surgical enhancement of the endolymphatic sac, a reasonably safe otologic procedure that also provides opportunity to reverse the conditions that favor the pathogenic conditions (such as malabsorption of endolymph) that are the likely cause of hydrops. The author tries to avoid labyrinthectomy because these patients may, in the future, be able to use a cochlear implant, and this is important * E-mail address: [email protected] (M.M. Paparella). 0030-6665/02/$ - see front matter Ó 2002, Elsevier Science (USA). All rights reserved. PII: S 0 0 3 0 - 6 6 6 5 ( 0 2 ) 0 0 0 3 2 - 4
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because some patients with Meniere’s disease can be susceptible to complete bilateral deafness. Some patients may have excellent results from ESE that may last 3 or 4 years, but then clinical symptoms such as vertigo or deafness can recur. The option of surgically revising their ESE is discussed with these patients, and they are also offered sectioning of the vestibular nerve when the original ESE has failed; however, only one of the author’s patients has required vestibular nerve section. In those who choose the revisional surgery, intraoperative findings, including extrasaccular fibrosis, osteoneogenesis, and aditus block are commonly seen. These symptoms mainly diminish, sometimes dramatically, after the revisional surgery. Those patients who choose revisional surgery obtain diminishment of their recurrent symptoms, but the surgeon also gains intraoperative insights that constitute a unique opportunity to study the pathogenesis of Meniere’s disease, something only observable in humans in vivo. After the 4-year period from July 1982 to July 1986, the author and colleague Hamed Sajjadi [1] assessed all their cases of revision of ESE that had had at least 2 years of follow-up. In this period, 26 ESEs were revised, an incidence of 7%. Because many of the original ESEs had been done years earlier (before 1982), however, the overall percentage rate for the period studied was only 4%. All patients had initially enjoyed good results from the ESE that diminished their symptoms, but the symptoms then gradually redeveloped in the following months and years. The asymptomatic period for these 26 patients ranged from 6 months to 11 years (average 2.6 years). Two patients had suddenly encountered recurrence of vertigo and hearing loss, one 2.5 years after the ESE and the other 3.5 years after ESE. One of the 26 patients had two revisions of the original ESE. Another had bilateral Meniere’s disease requiring one revision on the left ear and three revisions on the right ear (at the patient’s request) [1]. The patients’ reasons for requesting revisional surgery included both recurrent vertigo and hearing loss (in 22 patients) and hearing loss alone (in 4 patients). Two other patients received revisions of an ESE during this period because of immediate postoperative infection of the wound, but these two patients (who exhibited copious granulation tissue and aditus block in the mastoid cavity) are not included among the 26 revisions discussed here. In the included 26 patients, intraoperative findings in every case included primarily osteoneogenesis and scar tissue near the sac. Formation of the new bone was mostly from the adjacent region of the lateral sinus and from within the infralabyrinthine cell tract. In some of the initial ESEs, there had been insufficiently wide decompression and removal of bone [1]. The copious scar tissue seen in some was contiguous with the inferior margin of the wound and also near the mastoid tip. This scar tissue was always extrasaccular, not invading the lumen of the endolymphatic sac. This may have been due to the authors’ method of making a small opening in the sac below the solid bony angle, although the authors also revised some
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procedures that had been performed by other surgeons who did open the sac to the mastoid cavity. In the initial procedure in six patients who later developed a lot of scar tissue, grafting to protect the sac had been done using temporalis fascia, as was done routinely in those years. The authors discontinued this grafting in 1983 because of these findings seen upon revision [1]. When Silastic (Invotec International Inc., Jacksonville, FL) was removed from the sac, in every case it was yellowed, which suggests transudation of extracellular fluid. Epithelium in the lumen was shiny and intact. The aditus ad antrum was completely obstructed in 2 patients and partially obstructed in 11 patients who had formation of more tissue in the mastoid cavity. A bony shelf (operculum or anatomic variant) was seen on the subdural side in two patients; it obviated decompression at that site [1]. Four patients elected revision because of recurrence of hearing loss only (without vertigo); in three patients, hearing improved (average increase in discrimination, 24%; average increase in speech reception threshold, 16 dB), and in one patient, it stayed the same (Table 1). Surgery was done for recurrence of hearing loss and vertigo in the remaining 22 patients; 13 subsequently gained improved hearing and 9 stayed the same. Improvements in hearing averaged a 20% increase in discrimination and an 18 dB gain in speech reception threshold. Hearing loss and vertigo occurred suddenly, years after the initial procedure, in two patients in whom the authors then did an exploratory tympanotomy with endolymphatic sac revision because of the possibility of sudden deafness with perilymphatic fistula. Perilymphatic drainage was seen at the round window in one patient; in the other, perilymphatic drainage was strongly suggested, so the authors grafted the round windows. Both patients achieved improved hearing subsequent to revision. Vertigo was significantly improved in all but 1 of the 22 with recurrent hearing loss and vertigo, being eliminated in 12 and substantially controlled in 9. One patient required sectioning of the vestibular nerve [1]. Case reports Case 1 Classic Meniere’s disease with hearing loss and vertigo had been seen in this 29-year-old man for 8 years. After ESE, he had improvement of hearing, Table 1 Summary of results of revision of endolymphatic sac enhancement in 26 patients
Number of patients Hearing improved after revision Hearing the same after revision Vertigo eliminated by revision Vertigo controlled (improved) Vertigo the same after revision
Vertigo and deafness
Deafness
22 13 9 12 9 1
4 3 1
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elimination of vertigo, and diminution of other symptoms. Two and a half years after the initial ESE, his vertigo was still controlled but he had developed hearing loss and pressure in the operated ear. After discussion of the pros and cons of sac enhancement, revisional surgery was undertaken and, since then, he has improved hearing and his vertigo continues to be controlled (Fig. 1). Case 2 Intractable Meniere’s disease for 7 years was characterized in the left ear of this 36-year-old man by frequent incapacitating episodic vertigo, fluctuating sensorineural deafness, pressure, tinnitus, and inability to tolerate loudness. Fig. 2A shows his preoperative audiogram; Fig. 2B shows his postoperative audiogram. After the sac enhancement, hearing in the left ear improved in subsequent years, and the patient was free of vertigo for 4 years, when he developed severe symptoms including incapacitating vertigo, pressure, and ‘‘deafness’’ confirmed by shouting and testing using tuning forks while the other ear was masked. Serial audiograms were done by two audiologists approximately 5, 6, and 7 months into recurrence (Fig. 2C, D, and E). The patient considered both ESE and nerve section, and selected ESE.
Fig. 1. Audiographic findings in Case 1 are shown (A) before the initial ESE. After surgery, hearing improved in the right ear and vertigo ceased. Then, in 1982, symptoms of deafness recurred (B). (C) Audiogram shows that hearing was restored after the revisional surgery (results shown 1 year postoperatively). (From Paparella MM, Sajjadi H. Endolymphatic sac revision for recurrent Meniere’s disease. Am J Otol 1988;9(6):441–7; with permission.)
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Fig. 1 (continued )
Intraoperative findings included a characteristically reduced Trautmann’s triangle with much new bone and scar tissue growing into the region near the sac. The authors aggressively enlarged the infralabyrinthine bony cell tract, removed bone and scar tissue, widely decompressed the lateral sinus, and revised the sac enhancement. This patient remains free of vertigo and other symptoms, with dramatic return of improved hearing equaling or
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Fig. 2. (A) Audiogram for Case 2 obtained before initial ESE. (B) Postoperative audiogram showing retained hearing. Vertigo was gone. (C, D, E) Four years later, the patient developed recurrent incapacitating symptoms including deafness and vertigo. Recurrent deafness was repeatedly confirmed over a series of 3 months in the second quarter of the fourth year following initial ESE; speech discrimination was 0 each time. Four and three fourths years after initial ESE, revisional surgery was done. (F) Ten months postoperatively, the results after revision returned to or exceeded the levels before the original ESE, and vestibular and other symptoms remained absent. (From Paparella MM, Sajjadi H. Endolymphatic sac revision for recurrent Meniere’s disease. Am J Otol 1988;9(6):441–7; with permission.)
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Fig. 2 (continued )
bettering the initial preoperative level before the first ESE; follow-up audiogram taken 9 months postoperatively demonstrates these results (Fig. 2F). Although results in another two patients in the study were not this dramatic, they too had hearing restored from ‘‘deafness’’ to useful hearing, after the revisional surgery.
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Fig. 2 (continued )
Case 3 Bilateral incapacitating intractable Meniere’s disease was seen in this 31-year-old woman, a supervisory nurse who complained of recurrent vertigo and hearing loss in one ear. Her left ear received the first ESE; 1 year later, the right ear received an ESE. Three years later, the left ear received revisional surgery. Revisions on the right ear were done at 1 year, 6.5 years,
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and 8.5 years following initial ESE. Because this patient was well read about Meniere’s disease and had experienced relief of symptoms following revisional surgery, she continued to elect sac revisions even though nerve section was recommended. Each time she achieved elimination of vertigo and pressure and felt well, but the symptoms recurred later. She has remained well since her last procedure (Fig. 3). In our total series of cases, only 5% have needed a second revision; this patient’s four revisions are unique.
These observations prompted modifications of our procedure As described elsewhere [2], because of these observations made at revisions of ESEs, the author’s clinic now treats the wound differently. First, because several cases previously had problems chiefly with postoperative infection of the wound, an elliptic incision at least 1 inch behind the postauricular crease is now made, ending posterior to the mastoid tip inferiorly so that the line of incision does not cross the open mastoid cavity. The skin is elevated alone or with periosteum attached. The skin, which often contains a thick dermis, is now thinned with plastic scissors to discourage fibroblastic invasion from this site into a hypoplastic mastoid. At the end of the procedure, the debris is meticulously removed from the wound and all subcutaneous bleeders are controlled to prevent blood entering the mastoid, which can promote scarring and formation of granulation tissue. The wound is carefully closed in layers.
Fig. 3. Postoperative audiogram for Case 3 after revisional surgery. (From Paparella MM, Sajjadi H. Endolymphatic sac revision for recurrent Meniere’s disease. Am J Otol 1988;9(6): 441–7; with permission.)
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Second, a complete mastoidectomy is done, with wide exposure. The sac is usually found anterior and inferior to the posteroinferior semicircular canal. The lateral sinus (usually abnormally located medially and anteriorly) is widely exposed and the bone over it is removed. In some revisions, it was noticed that the lateral sinus had not been as widely decompressed initially as it should have been so that bone remaining in a remote region would not allow effective decompression of the dura and contiguous sac. Because bone from the lateral sinus can create osteoneogenesis growing toward the sac, a meticulous effort is made not to leave bone on the lateral sinus. Third, modifications were made to open widely the aditus contiguous with the suprapyramidal or facial recess not only to expose the incus and its fossa incudis as an important landmark but also to encourage good aeration between middle ear and mastoid cavity. Fourth, to ensure wide decompression, bone is removed widely over Trautmann’s triangle and over the entire lateral sinus to decompress all available lateral sinus and dura of the posterior cranial fossa that contains the sac, in a general and exaggerated way. This decompression is enhanced by using coiled Silastic spacers that act as loose springs to separate the tight dura from the bone of the solid angle. Fascia is no longer used to cover the sac, but rather an ‘‘apron’’ of Silastic is used to protect against fibroblastic invasion. A Silastic T-strut (small, medium, or large) is shaped and coiled within the lumen of the sac, and spacers are used to decompress the dura above and below the sac, as much as possible. Opening the sac widely under the solid angle, Silastic spacers are used to contain the environment of the sac to this region rather than letting it possibly extend toward the open mastoid cavity. Fifth, a myringotomy and ventilation tube routinely is placed in the anterior tympanic membrane to promote healing, drainage, and ventilation, to help avoid otitis media (the author has noted, for example, that in a few of these patients, otitis media may be related to flying), and to help aerate the mastoid in an attempt to discourage aditus block syndrome, osteneogenesis, and formation of fibrous tissue in the mastoid during the first postoperative year. Finally, in recent years, it has been observed that saturation and perfusion of the endolymphatic sac with gentamicin during this procedure, including gentamicin exposure to the round window for a 7- to 10-minute period in patients who have a severe hearing loss, has been a helpful clinical adjunct in eliminating vertigo in patients undergoing revision of sac surgery.
Discussion Clinical implications of revisions of ESE It is probable that because patients had already had good primary results from the initial ESE, revisional surgery resulted in decreases in vertigo and
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improvement in hearing that were even better than those from the initial ESE. Years later, iatrogenic osteoneogenesis and formation of scar tissue recreated the pathogenic conditions, and then the correction of these secondary lesions provided an even better chance for beneficial results. At the time of revision, primary findings to be corrected include formation of extrasaccular bone and fibrous tissue, aditus block, tight dura near the sac, and yellowed Silastic within and near the sac. After revisional surgery, resultant hearing has been significantly better (twice as good, increasing at least 15 dB in speech reception threshold and gaining 15% in speech discrimination) in 62% of our patients receiving a revision of ESE; the initial ESE produced significantly better hearing in only 30% to 40%. Dramatic restorations of hearing have been achieved in some patients who received revisions of ESE who went from deafness to useful hearing (see particularly the audiograms for Case 2, Fig. 2A–F). In three of these four patients, recurrent hearing loss that occurred alone improved. Those who had both recurrent vertigo and hearing loss had control or elimination of vertigo in 95% after revisions of ESE, and only one patient to date later had a vestibular nerve section. In the two patients in whom there was sudden recurrence of hearing loss, vertigo, or both after an initially good result of ESE, an associated perilymphatic fistula of the round window was identified and treated. Risks were found to be nonexistent from revisions of ESE in this study, and the results were gratifying. All patients but one continue to do well with this conservative therapy; only one patient required intracranial vestibular nerve section. These results indicate that patients who have good results following sac enhancement procedures but then later develop delayed recurrence of symptoms such as vertigo or hearing loss can be considered for revisional surgery that can even be repeated, if necessary. If vertigo continues as the primary problem, then retrolabyrinthine vestibular nerve section or physical or chemical labyrinthectomy can still be considered, although every effort is made to avoid this because a significant number of patients with Meniere’s disease develop bilateral deafness eventually, and labyrinthectomy will compromise future consideration of a cochlear implant. Since the 1982 to 1986 period reported on in this study, which had a relatively limited number of patients, many other patients have demonstrated similar findings and, in fact, better results may be obtained in revision than those resulting from the initial ESE. Pathogenesis of natural and ‘‘induced’’ Meniere’s disease From observations made in revision of ESE where each patient serves as his or her own control, clinicians can gain insights into the nature, cause, pathogenesis, and treatment of Meniere’s disease. Conditions in these patients provide a unique opportunity to study the natural history of this disease found only in humans in vivo and to make a diagnosis of intractable
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Meniere’s disease and treat it (in this case, with ESE), only to have symptoms recur later after developing conditions can be seen. ESE is designed to reverse conditions that appear to contribute to the fundamental pathogenic process of this disease—the malabsorption of endolymph—and these patients also had good results, typically for a few years after their initial sac enhancement procedures. When they became candidates for revisional surgery, the delayed and gradual rebuilding of those conditions after iatrogenic inducement could be observed intraoperatively. There can be osteoneogenesis, fibrosis, and granulation tissue causing a very tight and constricted dura, Trautmann’s triangle, and saccular region, resulting in obvious pressure or obstruction to this region. When these lesions are corrected and the dura is decompressed or loosened during revisional surgery, most patients once again have elimination or control of symptoms. Most patients who receive ESE benefit for a lifetime, but about 7% of the author’s patients who have had an ESE later have recurrences and require revision, usually many years after an initially good result. These circumstances provide an opportunity to observe the natural history of this disease, diagnose and treat it, observe clinical improvement after treatment (ESE), observe the delayed results of the recreated diseased conditions with all the clinical manifestations, observe those lesions intraoperatively and treat them, and then once again see resolution of clinical symptoms. The findings seen in this process appear to substantiate observations that the natural pathogenesis of Meniere’s disease involves endolymphatic malabsorption from conditions that ESE counteracts. Revisions of ESE counteract and treat pathogenic conditions that may have been induced (or not sufficiently prevented) by the former surgery. During these revisions, an important intraoperative finding is that Silastic removed from the lumen of the sac is yellowed, suggesting the occurrence of extracellular transudation. It can be hypothesized that this yellowing is from spinal fluid (as in shunting procedures draining the endolymphatic sac to the subarachnoid space) or from extracellular transudate creating the environment in the lumen of the sac, and it can be hypothesized that there is an osmotic pump or pull effect in which sodium ions near the formerly treated sac have pulled potassium ions from the opposite end of the endolymphatic duct. The following are hypotheses concerning the mechanisms by which ESE and its revisions might work to counteract pathogenic conditions that are based on the author’s observations intraoperatively in these surgical revisions and also on laboratory and clinical research. Hypothesis concerning decompression Due to pathologic anatomic abnormalities (some of which may be genetic), patients have a tight endolymphatic sac and contiguous dura and, particularly, a medially and anteriorally displaced lateral sinus. This abnormality requires complete simple mastoidectomy, wide removal of
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bone from over Trautmann’s triangle, the lateral sinus, and the area of the infralabyrinthine cell tract, and decompression of the dura from the solid angle. Decompression is enhanced by use of Silastic T-stuts to enlarge the lumen and the use of Silastic spacers to loosen dura from bone above and below the sac. It is hypothesized that decompression is the most important surgical contribution to counteracting the important pathogenic mechanism of obstruction of a tightened, restricted sac and dura. Hypothesis concerning osmotic pull Between the extracellular milieu within and near the sac (high in sodium) and endolymph on the other side of the vestibular aqueduct (high in potassium), there is an osmotic pressure-differential created. The transudate produced in this flow yellows Silastic that was placed in the sac at initial ESE. This environment is made not in the mastoid cavity but rather between bone and dura. Comparatively, Silastic retrieved from the middle ear in hundreds of surgical revisions of tympanoplasty retains its original clear color. Hypothesis concerning passive diffusion of endolymph By providing an enlarged, decompressed saccular lumen and Silastic (alloplastic) T-struts within the lumen, surfaces are provided against which nanoliters of endolymph can move passively. The Silastic may act as a wick exiting the sac to lie under bone, not in the mastoid cavity. Hypothesis concerning altered blood supply When the blood supply around the sac is surgically manipulated, collateral blood supply may be encouraged. This region is isolated by the Silastic ‘‘apron’’ separating the sac from the mastoid cavity to help prevent fibroblastic invasion. ESE or revision of the procedure may also alter immune properties in the sac. References [1] Paparella MM, Sajjadi H. Endolymphatic sac revision for recurrent Meniere’s disease. Am J Otol 1988;9(6):441–7. [2] Paparella MM. Endolymphatic sac procedures. In: Brackmann DE, Shelton C, Arriaga MA, editors. Otologic Surgery. 2nd edition. Philadelphia: W.B. Saunders; 2001. p. 371–84.