Journal of the Royal Society of Medicine Volume 83 July 1990
Surgery of the ethmoids - past, present and future:
a
451
review
Valerie J Lund MS FRCS Professorial Unit, Institute of Laryngology & Otology, 330/332 Gray's Inn Road, London WC1X 8EE Keywords: ethmoids; anatomy; pathophysiology; surgery; audit
Paper read to Section of
Introduction Functional endoscopic sinus surgery is a new technique for an old problem. In this overview of ethmoidal surgery, an attempt is made to place functional endoscopic surgery in some perspective and as a consequence, mainly considers surgery for inflammation and infection. Anatomy In addition to the detailed surgical anatomy of the middle meatus it is important to emphasize the immense variation which can occur in this region. The concept of the middle ethmoids is anatomically incorrect as it is clear that the basal lamella obliquely divides the labyrinth into an antero-inferior group and a postero-superior group. Consequently this must be breached to enter the posterior system and it is a common beginner's error in ethmoidal surgery to mistake this for the roof. The middle turbinate thus has two attachments, superiorly and laterally to the lamina papyracea via the basal lamella. On coronal sections it is evident that the lamina papyracea is generally in line in the vertical plane with the medial wall of the maxilla but the medial orbital wall courses 2-3 mm medially as it travels from the apex of the orbit anteriorly, thus increasing the risk of breaching the orbit here (Figure 1). It is also of surgical importance to note that the roof ofthe ethmoid is thinnest medially around the anterior ethmoidal artery' and that considerable differences can occur in the position of the ethmoidal roofs relative to the cribriform plate, the level and slope of which can be variable and sometimes asymmetric (Figure 2). The anterior and posterior ethmoidal vessels provide important landmarks to the level of the cribriform plate but are also not without variation. The rule of 24-12-6 has been applied to the medial wall
Figure 1. Axial CT scan showing anterior medialzation of the lamina papyracea
Laryngology, 1 December 1989
Figure 2. Coronal CT scan showing asymmetry of the ethmoidal roofs
of the orbit2, representing respectively, the average distance in millimetres from the anterior lacimal crest to the anterior ethmoidal foramen, from anterior to posterior ethmoidal foramen and from posterior etoidal to optic canal but up to 16% of patients have no anterior ethmoidal foramen, 4.6% lack them bilaterally and 30% have multiple foramina3. The ability of the ethmoid cells to pneumatize the sphenoid and surround the optic canal, the proximity of the optic nerve and the internal carotid artery cannot be overemphasized and recent data suggest that bone is dehiscent around these structures in one fifth of the population4.
Pathophysiology The concept of the 'ostiomeatal complex' as the key to problems in this area is not a new one. The intimate relationship of the paranasal sinuses was recognized by Caldwell nearly a century ago who remarked on the close proximity of the sinus ostia and the consequences of anterior ethmoidal infection5. Subsequent work by Proetz, Hilding, Proctor and Messerklinger contributed to our knowledge of mucociliary clearance6-9. hn cases of inflammation and infection, the arbitary consideration of individual sinuses in isolation is no longer tenable and the upper respiratory tract, indeed the respiratory tract as a whole must be taken into account. Furthermore, the possibility of systemic disease must be considered in all patients. Diagnosis and treatment of predisposing conditions such as
0141-0768/90/ 070451-05/$02.00/0 © 1990 The Royal Society of Medicine
452
Journal of the Royal Society of Medicine Volume 83 July 1990
allergy, immune deficiency and problems of mucociliary clearance have implications on surgical intervention and its results. In a recent series of 47 patients with chronic mucopurulent rhino-sinusitis, 60% were found to be allergic and though none were grossly hypogammaglobulinaemic, nearly half had levels of immunoglobulin classes or subclasses which were lower than two standard deviations below the normal mean10. Similarly, the possibility of other conditions such as sarcoid, Wegener's or AIDS should be considered. Historical
From the outset, operations on the fronto-ethmoidal complex fell into two groups, those designed to facal enhance drinage and aeration whilst pres contour and those aimed at eradicating diseased mucosa disregarding osmesis. Mosher is credited in 1913 with the first description of -an intranasal ethmoidectomy based on careful ntl studies11. By 1929 he concluded that, theoretically, the operation was easy, but i practice it had proven to be one of the easiest operations with which to kill the patient12. Dissatisfaction with the procedure and its dangers led to the increasing use of the external approach advocated by Lynch, Howarth and Ferris i
Smith13-15 Surgical
cavity and imaging of the sinuses'9-21. The enormous
improvement in visualization afforded by fibre-optic endoscopes is self-evident indeed one's view with ordinary rhinoscopy is embarrassingly limited and the inadequacies of plain sinus X-rays necessitate more sophisticated radiology if surgery is to be undertaken. In a series of 50 CT scans of patients with symptoms of chronic rhino-sinusitis and abnormal findings on endoscopy, the anterior ethmoids were most frequently affected (54%), followed by the maxillary sinus (37%), posterior ethmoids (34%), frontal (26%) and sphenoid (9%). However, in only 5% were the anterior ethmoids affected alone and the majority of patients had multisinus involvement (62%). Only one patient had isolated maxillary disease associated with a dental remanant, and it is of interest that 27% had no pathological change whatsoever, even though the scans were performed within a couple of weeks of presentation. -
Functional endoscopic ethmoidectomy This surgical technique has been reported for use in the treatment of a number of conditions (Table 1). The details of the procedure have been well described in the literature20'= and it has the advantage of being frequently performed under local anaesthesia which is of importance as day-surgery increases.
options
Surgery specifically on the ethmoids includes: functional endoscopic ethmoidectomy intranasal ethmoidectomy transantral ethmoidectomy external ethmoidectomy Wigand'6 has further subdivided endoscopic ethmoidectomy into the following: exposure of the ostio-meatal complex, eg ethmoidal infundibulotomy, middle meatal antrostomy anterior partial ethmoidectomy posterior partial ethmoidectomy complete ethmoidectomy (with or without fenestration of the maxillary, frontal and sphenoid sinuses, middle turbinectomy and septal mobilization. Whilst the Messerklinger techniquel7 favours less radical surgery determined by the pathology encountered, Wigand has proposed more aggressive surgery performing a complete retrograde ethmoidectomy18. Preoperative investigation for fimctional endoscopic ethmoidectomy includes endoscopy of the nasal
Intranasal ethmoidectomy The two largest recent series are those of Eichel in 197323 and Freedman and Kern from the Mayo in 197924. Table 1 shows the indications listed by Dr Eichel, though in the Mayo series the majority of cases were for ethmoidal polyposis and this would seem the most frequent reason for its use of late. Transantral ethmoidectomy This procedure described by Jansen in 190225, and Horgan in 192626 approaches the ethmoids via a Caldwell-Luc which renders the anterior cells inaccessible unless combined with an intranasal approNch. It has limited application but has been used for chronic inflammation and infection of the maxillary and ethmoid sinuses and has been used as a route for orbital decompression (Table 1).
External ethmoidectomy A number of surgeons are associated with external approaches to the ethmoids, perhaps the best known
Table 1. Indications for ethmoidectomy Functional endoscopic
ethmoidectomy
Intranasal ethmoidectomy
Transantral ethmoidectomy External ethmoidectomy
Chronic sinusitis
Chronic sinusitis Acute recurrent sinusitis Ethmoidal polyps
Chronic sinusitis
Acute recurrent sinusitis Ethmoidal polyps Fronto-ethmoidal mucocoeles Orbital decompression Allergic fungal sinusitis
Olfactory dysfunction Periorbital abscess
Chronic sinusitis
Recurrent polyposis Fro-tbo-thmoidal mucocoeles Orbital decompression Orbitad decompression
Ethmoidal polyps
Complications of acute sinusitis
Hyposmia Headache Access
Journal of the Royal Society of Medicine Volume 83 July 1990
of whom are Lynch and Howarth both describing their operations in 192113,14. Their names are attached to this approach though Patterson, who is now associated with the inferior incision in the naso-jugal fold also described a superior approach, albeit 18 years later27. Surgical indications are shown in Table 1. It is apparent from an examination of the operative figures at the Royal National Throat, Nose and Ear Hospital during the last decade that a constant but relatively small number of each type of ethmoidectomy have been done annually (between 10 and 25 a year), whilst the numbers of other procedures for chronic sinusitis (Caldwell-Luc and inferior meatal antrostomy) are fallinge. This must be compared with the increasing popularity offunctional endoscopic surgery as judged by the number of papers presented on the topic at the International Symposium for Infection and Allergy of the Nose (ISIAN) meetings in 1988 and 1989, a rise of 4% to 19%. In view of its escalating popularity, it is important to answer a number of questions regarding the role of functional endoscopic ethmoidal surgery. Firstly it is worth doing, given that there are other well-established approaches. A number of large personal series are available9'30 but few have attempted clinical trials to compare the surgical success of functional endoscopic surgery with conventional approaches or to compare for example Messerklinger versus Wigand techniques17'18. Indeed such a task is fraught with difficulties as strict inclusion criteria limit the number who can be entered into such a study and as Caldwell5 pointed out 'a staging system' is necessary to have meaningful results' - something we still lack and which renders clinical evaluation of these patients problematic. Unlike malignancy where patient survival provides the ultimate criterion of success, one must rely on subjective impressions and visual analogue scoring. However, these may be adequate if combined with endoscopy and it may also be possible to measure objectively improvements in airway resistance, olfaction and ciliary function. In 65 patients undergoing inferior meatal antrostomy, 84% of patients derived benefit as a whole but of these 42% continued to experience a post-nasal discharge which was the same or worse than preoperatively28. Based on the recent CT fmdings
_~~~~~~-
E, _
anrstme
an
ethmoidal regions
Y
i4
eiul dies inteotoetl
an
one must assume that most if not all of these patients
had concomitant ethmoiditis and ostio-meatal obstruction (Figure 3) but this gives an indication of the necessary degree of improvement which functional endoscopic surgery must achieve to be a reasonable
alternative. It is, therefore, of interest to compare the results of this surgery with conventional techniques for some other surgical indications. In the treatment of polyps, surgical success, ie non-recurrence has been reported at between 62% and 75% for large series3132 treated by intranasal ethmoidectomy. This can be compared with 82% for 220 cases managed by complete functional ethmoidectomy16. However, the length of follow-up is not always discussed so it is of interest to consider 10 patients who had 20-year follow-up following external ethmoidectomy and who had had between two and 10 intranasal removals of polyps prior to external surgery. This significantly lengthened the interval between this operation and the next intrasal procedure but only 'cured' two of the patients33. With fronto-ethmoidal mucocoeles, a fundamental issue is whether opening of the frontal recess per se is adequate or, for that matter, feasible in all patients. It is known that obstruction alone cannot be the only aetiological factor in this condition as evidenced by its rarity in the face of frequent frontal recess occlusion which is often bilateral3w. In the three largest series for each technique, recurrence rates of 0%, 4% and 5% have been reported3638 for functional endoscopic surgery, external ethmoidectomy and the osteoplastic flap approach, respectively. The numbers in these series were 15, 100 and 116 and follow-up was between 2 and 42 months, 3-19 years and 3-27 years, respectively. In a condition which may take 24 years to develop, the importance of large numbers with long-term follow-up is fundamental before success can be claimed. Little comparative data has been published on orbital decompression. A number of different approaches have been described. Sewall39 first described a route into the sinuses medially while Hirsch4O reported inferior decompression into the antrum. Ogura41 advocated a combination of these two methods but in our own series the Patterson's approach has been used allowing removal of the medial wall and floor from the ethmoidal vessels to the inferior orbital nerve and facilitating the periosteal incisions3. In expert hands a similar amount of bone can be removed endoscopically42, but with less ease and speed than a Patterson approach which does not usually produce a cosmetic problem. Allergic fumgal sinusitis is a rare condition ornally described by Waxman though probably underdiagnosed43. It is characterized by polypoid mucosal change associated with eosinophils, Charcot Leyden crystals and the presence of non-invasive fungal hyphae, usually ofthe Aspergillus species. A characteristic green sludge fills the sinuses. A small series have recently been successfully treated by a variety of surgical techniques, including endoscopic ethmoidectomy, success being dependant on aeration of the affected area4. The use of endoscopic ethmoidal surgery in the treatment of hyposmia with and without polypoid change in and around the olfactory niche is in its infancy not least because of the lack until recently
453
454
Journal of the Royal Society of Medicine Volume 83 July 1990
of objective measurements of olfaction, though a number of reports have recently appeared45. With regard to the complications of acute sinusitis, in particular periorbital abscess17, concern has been expressed by the proposal of an endoscopic approach which requires considerable confidence in one's surgical technique and at present an external approach must offer the most reliable results when vision
is in
jeopardy.
However, that aside ifthere is a place for functional endoscopic sinus surgery, can we -actually afford to do it. An analogy has been made between this surgery and otology and there are certainly some similarities when considering aspects of medical audit. In considering the cost in terms of time, we are in a comparable situation to the otologist faced with the introduction of the Zeiss microscope which tolled the death knell ofthe hammer and the gouge for a 'quick' mastoidectomy. However, time is surely not the principle arbiter especially if the technique ultimately decreases the need for future medication and surgery, but the emphasis on intensive postoperative care, which may be initially daily and then weekly for some months should also be costed. With regard to the not inconsiderable cost of endoscopes, light sources and instruments, this is of a similar order to equiping a department with a microscope and otological instruments. The need for more sophisticated radiology poses a more difficult problem. There are approximately 140 scanners in the United Kingdom capable of imaging the head and neck, 1/420 000 of the population46 which would clearly be inadequate if used to investigate all patients with chronic rhino-sinusitis. Although ethmoidectomy can and has been done without the benefit of such sophisticated radiology, some imaging of the region is desirable, some would say indispensable. High-quality hypocycloidal tomography would be a reasonable alternative to CT but few departments now have fimetioning mach The lack of available scanners should not necessarily be a deterrent, rather it should encourage discussion of the problem with radiologists to ensure the optimum sections and bone window widths are used. However it is likely that medicolegal pressure will ultimately determine the use of preoperative scanning as one must ask oneself if one would undergo endoscopic ethmoid surgery without the surgeon having the benefit of such information. Indeed it would be the ultimate surgical conceit to dismiss such information as unnecessary. Patient selection is clearly paramount if the system is not to be overburdened by these requests and it
is apparent that a plain lateral sinus film taken at 140 kV readily-available in any X-ray department, will give a reasonable indication of ethmoidal disease until such time as resources permit more liberal investigation. However, as abnormalities can be demonstrated on scans of ostensibly normal indivi-
duals, these radiological findings should merely provide corroborative data to clinical symptoms and endoscopic fmdings. The cost of training has also to be considered as to quote Eichel 'the inability to execute a procedure properly because of lack of training does not seem to be a fair argument in condemning a particular method'47. This may be facilitated by the use of moder technology such as microchip camera ystems. There is a considerable learning curve and it may require many cases to perform the operation well. Numerous cadaver dissections are required before attempting the operation in patients, material which is less readily obtainable than isolated temporal bones. This raises the question of whether it is an operation which should be done by everyone or whether, as has been suggested for stapedectomy, it should be confined to certain training programmes or centres. However, unlike otoelerosis, one is disuing a much commoner condition which will continue to be even when the potential backlog is cleared. Finally one must consider operative morbidity. In all the large series, morbidity and mortality have been minimal yet problems can arise with any ofthe techniques (Table 2). A recent series by Stankiewicz of 180 patients treated by a functional endoscopic technique reported a 9.3% complication rate virtually all of which occurred in the first 90 cases". Nevertheless such complications can occur with any ethmoidal surgery and Maniglia reported 13 patients with major problems following conventional intranasal ethmoidectomy, including seven cases of blindness, four CSF leaks and two deaths"9. Clearly there are many questions still unanswered. One should not dismiss a technique because it is difficult to do well but nor should one abandon wellestablished procedures in one's enthusiasm to follow a fashionable trend before it has been fully evaluated. The role of functional endoscopic sinus surgery has yet to be established in otorhinolaryngology but, based on my own experience of the procedure, I am confident that it wfill occupy an increasingly important position in the future, fudamentally changing our approach to benign disease in the nose so
and sinuses.
Dr Caldwell's operation may no longer be i
f
n
Table 2. Complications of ethmoidal surgery
No.
CSF Orbital Nasokgcrimal k Death Blindness haematoma Meningitis rhinorrho*a duct damage Haemorrhige
Intranasal
ethmoidectomy Freedman & Kern' Functional endoscopic ethmoidectomy Wigand 16
StammbergeP
~
External ethmoidectomy Harrison & Lund
1000 0
0
0.4%
0.1%
0.1%
0.1%
600 0 4000 0
0 0
-
0.5%
0.3% 0
0.5%
0.2%
320 0
0
0
0
0
0.6%
1.2%
-
0
Journal of the Royal Society of Medicine Volume 83 July 1990
but his remarks are as pertinent today as they were in 1893: 'The frequency with which sinus disease is recognised is in proportion to the care with which the sinuses are explored.'5 References 1 Stammberger H. Technique highlights and results of functional endoscopic sinus surgery. Presented VII ISIAN meeting, Baltimore, 1989 2 Rontal E, Rontal M, Guildford FT. Surgical anatomy of the orbit. Ann Otol Rhinol Laryngol 1979;88:382-6 3 Harrison DFN. The ENT surgeon looks at the orbit. J Laryngol Otol 1980;Suppl 3:1-43 4 Hassab MH, Kennedy DW. The internal carotid artery as it relates to endonasal sphenoethmoidectomy. Presented VII ISIAN meeting, Baltimore, 1989 5 Caldwell GW. Diseases of the accessory sinuses of the nose and an improved method of treatment for suppuration of the maxillary antrum. NY Med J 1893;58:526-8 6 Proetz AW. Essays on the applied physiology ofthe nose. St Louis: Annals Publishing Company, 1941 7 Hilding AC. Physiologic basis of nasal operations. California Med 1950;72:103-7 8 Messerklinger W. Uber Drainage der menschlichen nasennebenhohlen under normalen und pathologischen Bendingungen II Mitteilung: Die Stirnhohle und ihr Ausfurhrungssystem. Monatsschr Ohrenheilk 1967; 101:313-26 9 Proctor DF, Andersen I, eds. The nose: upper airway physiology and the anmospheric environment. Amrda Elsevier Biomedical, 1982 10 Lund VJ, Scadding GS. Tmmunologic aspects of chronic sinusitis. Can J Otolaryngol (in press) 11 Mosher HP. The applied anatomy and intranasal surgery of the ethmoidal labyrinth. Laryngoscope
1913;23:881-901 12 Mosher HP. The applied anatomy of the ethmoidal labyrinth. Ann Otol Rhinol Laryngol 1929;38:869-901 13 Lynch RC. The technique of a radical frontal sinus operation which has given me the best results Laryngoscope 1921;31:1-5 14 Howarth W. A radical frontal sinus operation. JLoryngol Otol 1921;38:341-3 15 Smith F. Management of chronic sinus disease. Arch Otolaryngol 1934;19:158-71 16 Wigand ME, Hosemann W. Microsurgical treatment of recurrent nasal polypesis. Rhinology 1989;Suppl 8:25-30 asal surgery - concepts 17 Stammbr H. E pic e in recurrin rhinosnusitis. Otolayngol Head Neck Surg
1986;94:143-56 18 Wigand ME, Steiner W, Jaumann MP. Endonasal sinus surgery with endoopical control: from radical operation to rehabilitation of the mucosa. Endoscopy 1978; 10:255-60 19 Kennedy DW, Zinreich J, Rosenbaum AE, Johns ME. Functional endoscopic sinus surgery. Theory and dignostic evaluation. Arch Otolaryngol 1985;11:576-82 20 Stammberger H. Nasal and parsl sinus endoscopy: a diagnostic and surgical approach to recurent sinusitis.
Endoscopy 1986;18:211-18 21 Zinreich SJ, Kennedy DW, Rosenbaum AE, et aL Paranasal sinuses: CT imaging requirements for
endoscopic surgery. Radiology 1987;163:769-75 22 Kennedy DW. Functional endoscopic sinus surgery. Technique. Arch Otolaryngol 1985;111:643-9 23 Eichel BS. The intranasal ethmoidectomy procedure: historical, technical and clinical considerations. Laryngoscope 1972;82:1806-21 24 Freeman HM, Kern EB. Complications of intranasal ethmoidectomy: a review oi 1000 conseutive operations. Laryngoscope 1979;89:421-34
25 Jansen A. Die Killian'sche Radical-Operation Chronischer Stirnhohleneiterungen. Ohren Nasen Kehlkoptheil 1902; 56:110-12 26 Horgan JB. The surgical approach to the ethmoidal cell system. J Laryngol Otol 1926;41:510-21 27 Patterson N. External operations on the frontal and ethmoidal sinuses. J Laryngol Otol 1939;54:235-44 28 Lund VJ. Inferior meatal antrostomy. University of London: MS thesis, 1987 29 Stammberger H. Headaches and sinus disease: the endoscopic approach. Ann Otol Rhinol Laryngol 1988; 97(Suppl 134):1-23 30 Stammberger H, Zinreich SJ, Kopp W, et aL Surgical treatment of chronic recurrent sinusitis - the CaldwellLuc versus a functional endoscopic technique. HNO 1987;35:93-105 31 Dixon F. The clinical significance of anatomical arrangement of the paranasal sinuses. Ann Otol Rhinol Laryngol 1958;67:736-41 32 Simonton K. The comprehensive surgical treatment of nasal polyposis. Trans Am Acad Ophthal Otolaryngol 1958;65:75-81 33 Toe M, Drake-Lee A, Lund VJ, Stammberger H. Treatment of nasal polyps - medication or surgery. Rhinology 1989;Suppl 8:45-9 34 Lund VJ. Anatomical considerations in the aetiology of fronto-ethmoidal mucocoeles. Rhinology 1987;25:83-8 35 Lund VJ, Harvey W, Meghji 8, Harris M. Prostaglandin synthesis in the pathogenesis of fronto-ethmoidal mucocoeles. Acta Otolaryngol 1988;106:145-51 36 Kennedy DW, Josephson JS, Zinreich J, Mattox DE, Goldsmith MM. Endoshpic sinus surgery for mucoceles: a viable alternative. Laryngosope 1989;909885-95 37 Rubin JR, Lund VJ, Salmon BS. Fronto.ethmoidectomy in the treatment of mucoceles - a neglected operation. Arch Otolaryngol 1985;112:434-6 38 Hardy JM, Montgomery WW. Osteoplastic frontal sinusotomy. Ann Otol Rhinol Laryngol 1976;85:523-32. 39 Sewall EC. Operative control of progressive exophthalmos. Arch Otolaryngol 1936;24:621-4 40 Hirsch 0. Surgical decompression for malignant exophthalmos. Arch Otolaryngol 1950;51:325-31 41 Ogura JH. Surgical results of orbital decompression for malignant exophthalmos. J Laryngol Otol 1978;92: 181-96 42 Goldstein ML, Kennedy DW, Zinreich SJ, Miller N. A prelimninary report - transnasa endoscopic deompression in dysthyroid orbitopathy. Presented VIII ISIAN meeting, Baltimore, 1989 43 Waxman JE, Spector JG, Sale SR, Katzenstein AA. Allergic aspergillus sinusitisc oncepts in diagnosis and treatment of a new clinical entity. Laryngoscope
1987;97:261-6 44 Jonathen D, Lund VJ, Milroy C. Allergic aspergillus sinusitis- an overlooked diagnosis. J Laryngol Otol 1989;103:1181-6 45 Wigand ME, Goertzen W, Hosemann W. Olfaction after endoscopic ethmoidectomy. Presented VIII ISIAN meeting, Baltimore, 1989 46 Hewer RL, Wood VA. Availability of computed tomography of the brain in the United Kingdom. Br Med J
1989;298:1219-20 47 Eichel BS. Surgical management of chronic paranasal sinusitis. Laryngoscope 1973;83:1195-203 48 Stankiewiz JA. Complications in endoscopic inanasal ethmoidectomy: an update. Laryngosope 1989;99: 686-90
49 Maniglia AJ. Fatal and major complications secondary to nasal and sinus surgery. Larngoscope 1989;99: 276-8&
(Accepted 13 March 1990)
455
Surgery of the ethmoids - past, present and future:
a
451
review
Valerie J Lund MS FRCS Professorial Unit, Institute of Laryngology & Otology, 330/332 Gray's Inn Road, London WC1X 8EE Keywords: ethmoids; anatomy; pathophysiology; surgery; audit
Paper read to Section of
Introduction Functional endoscopic sinus surgery is a new technique for an old problem. In this overview of ethmoidal surgery, an attempt is made to place functional endoscopic surgery in some perspective and as a consequence, mainly considers surgery for inflammation and infection. Anatomy In addition to the detailed surgical anatomy of the middle meatus it is important to emphasize the immense variation which can occur in this region. The concept of the middle ethmoids is anatomically incorrect as it is clear that the basal lamella obliquely divides the labyrinth into an antero-inferior group and a postero-superior group. Consequently this must be breached to enter the posterior system and it is a common beginner's error in ethmoidal surgery to mistake this for the roof. The middle turbinate thus has two attachments, superiorly and laterally to the lamina papyracea via the basal lamella. On coronal sections it is evident that the lamina papyracea is generally in line in the vertical plane with the medial wall of the maxilla but the medial orbital wall courses 2-3 mm medially as it travels from the apex of the orbit anteriorly, thus increasing the risk of breaching the orbit here (Figure 1). It is also of surgical importance to note that the roof ofthe ethmoid is thinnest medially around the anterior ethmoidal artery' and that considerable differences can occur in the position of the ethmoidal roofs relative to the cribriform plate, the level and slope of which can be variable and sometimes asymmetric (Figure 2). The anterior and posterior ethmoidal vessels provide important landmarks to the level of the cribriform plate but are also not without variation. The rule of 24-12-6 has been applied to the medial wall
Figure 1. Axial CT scan showing anterior medialzation of the lamina papyracea
Laryngology, 1 December 1989
Figure 2. Coronal CT scan showing asymmetry of the ethmoidal roofs
of the orbit2, representing respectively, the average distance in millimetres from the anterior lacimal crest to the anterior ethmoidal foramen, from anterior to posterior ethmoidal foramen and from posterior etoidal to optic canal but up to 16% of patients have no anterior ethmoidal foramen, 4.6% lack them bilaterally and 30% have multiple foramina3. The ability of the ethmoid cells to pneumatize the sphenoid and surround the optic canal, the proximity of the optic nerve and the internal carotid artery cannot be overemphasized and recent data suggest that bone is dehiscent around these structures in one fifth of the population4.
Pathophysiology The concept of the 'ostiomeatal complex' as the key to problems in this area is not a new one. The intimate relationship of the paranasal sinuses was recognized by Caldwell nearly a century ago who remarked on the close proximity of the sinus ostia and the consequences of anterior ethmoidal infection5. Subsequent work by Proetz, Hilding, Proctor and Messerklinger contributed to our knowledge of mucociliary clearance6-9. hn cases of inflammation and infection, the arbitary consideration of individual sinuses in isolation is no longer tenable and the upper respiratory tract, indeed the respiratory tract as a whole must be taken into account. Furthermore, the possibility of systemic disease must be considered in all patients. Diagnosis and treatment of predisposing conditions such as
0141-0768/90/ 070451-05/$02.00/0 © 1990 The Royal Society of Medicine
452
Journal of the Royal Society of Medicine Volume 83 July 1990
allergy, immune deficiency and problems of mucociliary clearance have implications on surgical intervention and its results. In a recent series of 47 patients with chronic mucopurulent rhino-sinusitis, 60% were found to be allergic and though none were grossly hypogammaglobulinaemic, nearly half had levels of immunoglobulin classes or subclasses which were lower than two standard deviations below the normal mean10. Similarly, the possibility of other conditions such as sarcoid, Wegener's or AIDS should be considered. Historical
From the outset, operations on the fronto-ethmoidal complex fell into two groups, those designed to facal enhance drinage and aeration whilst pres contour and those aimed at eradicating diseased mucosa disregarding osmesis. Mosher is credited in 1913 with the first description of -an intranasal ethmoidectomy based on careful ntl studies11. By 1929 he concluded that, theoretically, the operation was easy, but i practice it had proven to be one of the easiest operations with which to kill the patient12. Dissatisfaction with the procedure and its dangers led to the increasing use of the external approach advocated by Lynch, Howarth and Ferris i
Smith13-15 Surgical
cavity and imaging of the sinuses'9-21. The enormous
improvement in visualization afforded by fibre-optic endoscopes is self-evident indeed one's view with ordinary rhinoscopy is embarrassingly limited and the inadequacies of plain sinus X-rays necessitate more sophisticated radiology if surgery is to be undertaken. In a series of 50 CT scans of patients with symptoms of chronic rhino-sinusitis and abnormal findings on endoscopy, the anterior ethmoids were most frequently affected (54%), followed by the maxillary sinus (37%), posterior ethmoids (34%), frontal (26%) and sphenoid (9%). However, in only 5% were the anterior ethmoids affected alone and the majority of patients had multisinus involvement (62%). Only one patient had isolated maxillary disease associated with a dental remanant, and it is of interest that 27% had no pathological change whatsoever, even though the scans were performed within a couple of weeks of presentation. -
Functional endoscopic ethmoidectomy This surgical technique has been reported for use in the treatment of a number of conditions (Table 1). The details of the procedure have been well described in the literature20'= and it has the advantage of being frequently performed under local anaesthesia which is of importance as day-surgery increases.
options
Surgery specifically on the ethmoids includes: functional endoscopic ethmoidectomy intranasal ethmoidectomy transantral ethmoidectomy external ethmoidectomy Wigand'6 has further subdivided endoscopic ethmoidectomy into the following: exposure of the ostio-meatal complex, eg ethmoidal infundibulotomy, middle meatal antrostomy anterior partial ethmoidectomy posterior partial ethmoidectomy complete ethmoidectomy (with or without fenestration of the maxillary, frontal and sphenoid sinuses, middle turbinectomy and septal mobilization. Whilst the Messerklinger techniquel7 favours less radical surgery determined by the pathology encountered, Wigand has proposed more aggressive surgery performing a complete retrograde ethmoidectomy18. Preoperative investigation for fimctional endoscopic ethmoidectomy includes endoscopy of the nasal
Intranasal ethmoidectomy The two largest recent series are those of Eichel in 197323 and Freedman and Kern from the Mayo in 197924. Table 1 shows the indications listed by Dr Eichel, though in the Mayo series the majority of cases were for ethmoidal polyposis and this would seem the most frequent reason for its use of late. Transantral ethmoidectomy This procedure described by Jansen in 190225, and Horgan in 192626 approaches the ethmoids via a Caldwell-Luc which renders the anterior cells inaccessible unless combined with an intranasal approNch. It has limited application but has been used for chronic inflammation and infection of the maxillary and ethmoid sinuses and has been used as a route for orbital decompression (Table 1).
External ethmoidectomy A number of surgeons are associated with external approaches to the ethmoids, perhaps the best known
Table 1. Indications for ethmoidectomy Functional endoscopic
ethmoidectomy
Intranasal ethmoidectomy
Transantral ethmoidectomy External ethmoidectomy
Chronic sinusitis
Chronic sinusitis Acute recurrent sinusitis Ethmoidal polyps
Chronic sinusitis
Acute recurrent sinusitis Ethmoidal polyps Fronto-ethmoidal mucocoeles Orbital decompression Allergic fungal sinusitis
Olfactory dysfunction Periorbital abscess
Chronic sinusitis
Recurrent polyposis Fro-tbo-thmoidal mucocoeles Orbital decompression Orbitad decompression
Ethmoidal polyps
Complications of acute sinusitis
Hyposmia Headache Access
Journal of the Royal Society of Medicine Volume 83 July 1990
of whom are Lynch and Howarth both describing their operations in 192113,14. Their names are attached to this approach though Patterson, who is now associated with the inferior incision in the naso-jugal fold also described a superior approach, albeit 18 years later27. Surgical indications are shown in Table 1. It is apparent from an examination of the operative figures at the Royal National Throat, Nose and Ear Hospital during the last decade that a constant but relatively small number of each type of ethmoidectomy have been done annually (between 10 and 25 a year), whilst the numbers of other procedures for chronic sinusitis (Caldwell-Luc and inferior meatal antrostomy) are fallinge. This must be compared with the increasing popularity offunctional endoscopic surgery as judged by the number of papers presented on the topic at the International Symposium for Infection and Allergy of the Nose (ISIAN) meetings in 1988 and 1989, a rise of 4% to 19%. In view of its escalating popularity, it is important to answer a number of questions regarding the role of functional endoscopic ethmoidal surgery. Firstly it is worth doing, given that there are other well-established approaches. A number of large personal series are available9'30 but few have attempted clinical trials to compare the surgical success of functional endoscopic surgery with conventional approaches or to compare for example Messerklinger versus Wigand techniques17'18. Indeed such a task is fraught with difficulties as strict inclusion criteria limit the number who can be entered into such a study and as Caldwell5 pointed out 'a staging system' is necessary to have meaningful results' - something we still lack and which renders clinical evaluation of these patients problematic. Unlike malignancy where patient survival provides the ultimate criterion of success, one must rely on subjective impressions and visual analogue scoring. However, these may be adequate if combined with endoscopy and it may also be possible to measure objectively improvements in airway resistance, olfaction and ciliary function. In 65 patients undergoing inferior meatal antrostomy, 84% of patients derived benefit as a whole but of these 42% continued to experience a post-nasal discharge which was the same or worse than preoperatively28. Based on the recent CT fmdings
_~~~~~~-
E, _
anrstme
an
ethmoidal regions
Y
i4
eiul dies inteotoetl
an
one must assume that most if not all of these patients
had concomitant ethmoiditis and ostio-meatal obstruction (Figure 3) but this gives an indication of the necessary degree of improvement which functional endoscopic surgery must achieve to be a reasonable
alternative. It is, therefore, of interest to compare the results of this surgery with conventional techniques for some other surgical indications. In the treatment of polyps, surgical success, ie non-recurrence has been reported at between 62% and 75% for large series3132 treated by intranasal ethmoidectomy. This can be compared with 82% for 220 cases managed by complete functional ethmoidectomy16. However, the length of follow-up is not always discussed so it is of interest to consider 10 patients who had 20-year follow-up following external ethmoidectomy and who had had between two and 10 intranasal removals of polyps prior to external surgery. This significantly lengthened the interval between this operation and the next intrasal procedure but only 'cured' two of the patients33. With fronto-ethmoidal mucocoeles, a fundamental issue is whether opening of the frontal recess per se is adequate or, for that matter, feasible in all patients. It is known that obstruction alone cannot be the only aetiological factor in this condition as evidenced by its rarity in the face of frequent frontal recess occlusion which is often bilateral3w. In the three largest series for each technique, recurrence rates of 0%, 4% and 5% have been reported3638 for functional endoscopic surgery, external ethmoidectomy and the osteoplastic flap approach, respectively. The numbers in these series were 15, 100 and 116 and follow-up was between 2 and 42 months, 3-19 years and 3-27 years, respectively. In a condition which may take 24 years to develop, the importance of large numbers with long-term follow-up is fundamental before success can be claimed. Little comparative data has been published on orbital decompression. A number of different approaches have been described. Sewall39 first described a route into the sinuses medially while Hirsch4O reported inferior decompression into the antrum. Ogura41 advocated a combination of these two methods but in our own series the Patterson's approach has been used allowing removal of the medial wall and floor from the ethmoidal vessels to the inferior orbital nerve and facilitating the periosteal incisions3. In expert hands a similar amount of bone can be removed endoscopically42, but with less ease and speed than a Patterson approach which does not usually produce a cosmetic problem. Allergic fumgal sinusitis is a rare condition ornally described by Waxman though probably underdiagnosed43. It is characterized by polypoid mucosal change associated with eosinophils, Charcot Leyden crystals and the presence of non-invasive fungal hyphae, usually ofthe Aspergillus species. A characteristic green sludge fills the sinuses. A small series have recently been successfully treated by a variety of surgical techniques, including endoscopic ethmoidectomy, success being dependant on aeration of the affected area4. The use of endoscopic ethmoidal surgery in the treatment of hyposmia with and without polypoid change in and around the olfactory niche is in its infancy not least because of the lack until recently
453
454
Journal of the Royal Society of Medicine Volume 83 July 1990
of objective measurements of olfaction, though a number of reports have recently appeared45. With regard to the complications of acute sinusitis, in particular periorbital abscess17, concern has been expressed by the proposal of an endoscopic approach which requires considerable confidence in one's surgical technique and at present an external approach must offer the most reliable results when vision
is in
jeopardy.
However, that aside ifthere is a place for functional endoscopic sinus surgery, can we -actually afford to do it. An analogy has been made between this surgery and otology and there are certainly some similarities when considering aspects of medical audit. In considering the cost in terms of time, we are in a comparable situation to the otologist faced with the introduction of the Zeiss microscope which tolled the death knell ofthe hammer and the gouge for a 'quick' mastoidectomy. However, time is surely not the principle arbiter especially if the technique ultimately decreases the need for future medication and surgery, but the emphasis on intensive postoperative care, which may be initially daily and then weekly for some months should also be costed. With regard to the not inconsiderable cost of endoscopes, light sources and instruments, this is of a similar order to equiping a department with a microscope and otological instruments. The need for more sophisticated radiology poses a more difficult problem. There are approximately 140 scanners in the United Kingdom capable of imaging the head and neck, 1/420 000 of the population46 which would clearly be inadequate if used to investigate all patients with chronic rhino-sinusitis. Although ethmoidectomy can and has been done without the benefit of such sophisticated radiology, some imaging of the region is desirable, some would say indispensable. High-quality hypocycloidal tomography would be a reasonable alternative to CT but few departments now have fimetioning mach The lack of available scanners should not necessarily be a deterrent, rather it should encourage discussion of the problem with radiologists to ensure the optimum sections and bone window widths are used. However it is likely that medicolegal pressure will ultimately determine the use of preoperative scanning as one must ask oneself if one would undergo endoscopic ethmoid surgery without the surgeon having the benefit of such information. Indeed it would be the ultimate surgical conceit to dismiss such information as unnecessary. Patient selection is clearly paramount if the system is not to be overburdened by these requests and it
is apparent that a plain lateral sinus film taken at 140 kV readily-available in any X-ray department, will give a reasonable indication of ethmoidal disease until such time as resources permit more liberal investigation. However, as abnormalities can be demonstrated on scans of ostensibly normal indivi-
duals, these radiological findings should merely provide corroborative data to clinical symptoms and endoscopic fmdings. The cost of training has also to be considered as to quote Eichel 'the inability to execute a procedure properly because of lack of training does not seem to be a fair argument in condemning a particular method'47. This may be facilitated by the use of moder technology such as microchip camera ystems. There is a considerable learning curve and it may require many cases to perform the operation well. Numerous cadaver dissections are required before attempting the operation in patients, material which is less readily obtainable than isolated temporal bones. This raises the question of whether it is an operation which should be done by everyone or whether, as has been suggested for stapedectomy, it should be confined to certain training programmes or centres. However, unlike otoelerosis, one is disuing a much commoner condition which will continue to be even when the potential backlog is cleared. Finally one must consider operative morbidity. In all the large series, morbidity and mortality have been minimal yet problems can arise with any ofthe techniques (Table 2). A recent series by Stankiewicz of 180 patients treated by a functional endoscopic technique reported a 9.3% complication rate virtually all of which occurred in the first 90 cases". Nevertheless such complications can occur with any ethmoidal surgery and Maniglia reported 13 patients with major problems following conventional intranasal ethmoidectomy, including seven cases of blindness, four CSF leaks and two deaths"9. Clearly there are many questions still unanswered. One should not dismiss a technique because it is difficult to do well but nor should one abandon wellestablished procedures in one's enthusiasm to follow a fashionable trend before it has been fully evaluated. The role of functional endoscopic sinus surgery has yet to be established in otorhinolaryngology but, based on my own experience of the procedure, I am confident that it wfill occupy an increasingly important position in the future, fudamentally changing our approach to benign disease in the nose so
and sinuses.
Dr Caldwell's operation may no longer be i
f
n
Table 2. Complications of ethmoidal surgery
No.
CSF Orbital Nasokgcrimal k Death Blindness haematoma Meningitis rhinorrho*a duct damage Haemorrhige
Intranasal
ethmoidectomy Freedman & Kern' Functional endoscopic ethmoidectomy Wigand 16
StammbergeP
~
External ethmoidectomy Harrison & Lund
1000 0
0
0.4%
0.1%
0.1%
0.1%
600 0 4000 0
0 0
-
0.5%
0.3% 0
0.5%
0.2%
320 0
0
0
0
0
0.6%
1.2%
-
0
Journal of the Royal Society of Medicine Volume 83 July 1990
but his remarks are as pertinent today as they were in 1893: 'The frequency with which sinus disease is recognised is in proportion to the care with which the sinuses are explored.'5 References 1 Stammberger H. Technique highlights and results of functional endoscopic sinus surgery. Presented VII ISIAN meeting, Baltimore, 1989 2 Rontal E, Rontal M, Guildford FT. Surgical anatomy of the orbit. Ann Otol Rhinol Laryngol 1979;88:382-6 3 Harrison DFN. The ENT surgeon looks at the orbit. J Laryngol Otol 1980;Suppl 3:1-43 4 Hassab MH, Kennedy DW. The internal carotid artery as it relates to endonasal sphenoethmoidectomy. Presented VII ISIAN meeting, Baltimore, 1989 5 Caldwell GW. Diseases of the accessory sinuses of the nose and an improved method of treatment for suppuration of the maxillary antrum. NY Med J 1893;58:526-8 6 Proetz AW. Essays on the applied physiology ofthe nose. St Louis: Annals Publishing Company, 1941 7 Hilding AC. Physiologic basis of nasal operations. California Med 1950;72:103-7 8 Messerklinger W. Uber Drainage der menschlichen nasennebenhohlen under normalen und pathologischen Bendingungen II Mitteilung: Die Stirnhohle und ihr Ausfurhrungssystem. Monatsschr Ohrenheilk 1967; 101:313-26 9 Proctor DF, Andersen I, eds. The nose: upper airway physiology and the anmospheric environment. Amrda Elsevier Biomedical, 1982 10 Lund VJ, Scadding GS. Tmmunologic aspects of chronic sinusitis. Can J Otolaryngol (in press) 11 Mosher HP. The applied anatomy and intranasal surgery of the ethmoidal labyrinth. Laryngoscope
1913;23:881-901 12 Mosher HP. The applied anatomy of the ethmoidal labyrinth. Ann Otol Rhinol Laryngol 1929;38:869-901 13 Lynch RC. The technique of a radical frontal sinus operation which has given me the best results Laryngoscope 1921;31:1-5 14 Howarth W. A radical frontal sinus operation. JLoryngol Otol 1921;38:341-3 15 Smith F. Management of chronic sinus disease. Arch Otolaryngol 1934;19:158-71 16 Wigand ME, Hosemann W. Microsurgical treatment of recurrent nasal polypesis. Rhinology 1989;Suppl 8:25-30 asal surgery - concepts 17 Stammbr H. E pic e in recurrin rhinosnusitis. Otolayngol Head Neck Surg
1986;94:143-56 18 Wigand ME, Steiner W, Jaumann MP. Endonasal sinus surgery with endoopical control: from radical operation to rehabilitation of the mucosa. Endoscopy 1978; 10:255-60 19 Kennedy DW, Zinreich J, Rosenbaum AE, Johns ME. Functional endoscopic sinus surgery. Theory and dignostic evaluation. Arch Otolaryngol 1985;11:576-82 20 Stammberger H. Nasal and parsl sinus endoscopy: a diagnostic and surgical approach to recurent sinusitis.
Endoscopy 1986;18:211-18 21 Zinreich SJ, Kennedy DW, Rosenbaum AE, et aL Paranasal sinuses: CT imaging requirements for
endoscopic surgery. Radiology 1987;163:769-75 22 Kennedy DW. Functional endoscopic sinus surgery. Technique. Arch Otolaryngol 1985;111:643-9 23 Eichel BS. The intranasal ethmoidectomy procedure: historical, technical and clinical considerations. Laryngoscope 1972;82:1806-21 24 Freeman HM, Kern EB. Complications of intranasal ethmoidectomy: a review oi 1000 conseutive operations. Laryngoscope 1979;89:421-34
25 Jansen A. Die Killian'sche Radical-Operation Chronischer Stirnhohleneiterungen. Ohren Nasen Kehlkoptheil 1902; 56:110-12 26 Horgan JB. The surgical approach to the ethmoidal cell system. J Laryngol Otol 1926;41:510-21 27 Patterson N. External operations on the frontal and ethmoidal sinuses. J Laryngol Otol 1939;54:235-44 28 Lund VJ. Inferior meatal antrostomy. University of London: MS thesis, 1987 29 Stammberger H. Headaches and sinus disease: the endoscopic approach. Ann Otol Rhinol Laryngol 1988; 97(Suppl 134):1-23 30 Stammberger H, Zinreich SJ, Kopp W, et aL Surgical treatment of chronic recurrent sinusitis - the CaldwellLuc versus a functional endoscopic technique. HNO 1987;35:93-105 31 Dixon F. The clinical significance of anatomical arrangement of the paranasal sinuses. Ann Otol Rhinol Laryngol 1958;67:736-41 32 Simonton K. The comprehensive surgical treatment of nasal polyposis. Trans Am Acad Ophthal Otolaryngol 1958;65:75-81 33 Toe M, Drake-Lee A, Lund VJ, Stammberger H. Treatment of nasal polyps - medication or surgery. Rhinology 1989;Suppl 8:45-9 34 Lund VJ. Anatomical considerations in the aetiology of fronto-ethmoidal mucocoeles. Rhinology 1987;25:83-8 35 Lund VJ, Harvey W, Meghji 8, Harris M. Prostaglandin synthesis in the pathogenesis of fronto-ethmoidal mucocoeles. Acta Otolaryngol 1988;106:145-51 36 Kennedy DW, Josephson JS, Zinreich J, Mattox DE, Goldsmith MM. Endoshpic sinus surgery for mucoceles: a viable alternative. Laryngosope 1989;909885-95 37 Rubin JR, Lund VJ, Salmon BS. Fronto.ethmoidectomy in the treatment of mucoceles - a neglected operation. Arch Otolaryngol 1985;112:434-6 38 Hardy JM, Montgomery WW. Osteoplastic frontal sinusotomy. Ann Otol Rhinol Laryngol 1976;85:523-32. 39 Sewall EC. Operative control of progressive exophthalmos. Arch Otolaryngol 1936;24:621-4 40 Hirsch 0. Surgical decompression for malignant exophthalmos. Arch Otolaryngol 1950;51:325-31 41 Ogura JH. Surgical results of orbital decompression for malignant exophthalmos. J Laryngol Otol 1978;92: 181-96 42 Goldstein ML, Kennedy DW, Zinreich SJ, Miller N. A prelimninary report - transnasa endoscopic deompression in dysthyroid orbitopathy. Presented VIII ISIAN meeting, Baltimore, 1989 43 Waxman JE, Spector JG, Sale SR, Katzenstein AA. Allergic aspergillus sinusitisc oncepts in diagnosis and treatment of a new clinical entity. Laryngoscope
1987;97:261-6 44 Jonathen D, Lund VJ, Milroy C. Allergic aspergillus sinusitis- an overlooked diagnosis. J Laryngol Otol 1989;103:1181-6 45 Wigand ME, Goertzen W, Hosemann W. Olfaction after endoscopic ethmoidectomy. Presented VIII ISIAN meeting, Baltimore, 1989 46 Hewer RL, Wood VA. Availability of computed tomography of the brain in the United Kingdom. Br Med J
1989;298:1219-20 47 Eichel BS. Surgical management of chronic paranasal sinusitis. Laryngoscope 1973;83:1195-203 48 Stankiewiz JA. Complications in endoscopic inanasal ethmoidectomy: an update. Laryngosope 1989;99: 686-90
49 Maniglia AJ. Fatal and major complications secondary to nasal and sinus surgery. Larngoscope 1989;99: 276-8&
(Accepted 13 March 1990)
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