J Int Adv Otol 2018; 14(2): 216-26 • DOI: 10.5152/iao.2018.5553

Review

International Otology Outcome Group and theInternational Consensus on the Categorization of
Tympanomastoid Surgery
Matthew Yung , Adrian James , Paul Merkus , John Philips , Bruce Black , Tetsuya Tono ,Thomas Linder , John Dornhoffer , Armagan İncesulu
Department of Otolaryngology, East Suffolk and North Essex NHS Foundation Trust, Ipswich, United Kingdom (MY)
Department of Otolaryngology – Head & Neck Surgery, Hospital for Sick Children, University of Toronto, Toronto, Canada (AJ)
Department of Otolaryngology– Head & Neck Surgery, Section Ear & Hearing, VU University Medical Center, Amsterdam Public Health Research Institute,
Amsterdam, Netherlands (PM)
Norfolk & Norwich University Hospitals NHS Foundation Trust, Department of Otolaryngology, Norwich, United Kingdom (JP)Clinic of Otology, Queensland Otology, Brisbane, Australia (BB)
Department of Otolaryngology-Head and Neck Surgery, University of Miyazaki, Miyazaki, Japan (TT)Department of Otorhinolaryngology – Head & Neck Surgery, Kantonsspital Luzern, Luzern, Switzerland (TL)
Department of Otolaryngology - Head and Neck Surgery, University of Arkansas for Medical Sciences, Arkansas, USA (JD)
Department of Otolaryngology-Head & Neck Surgery, Eskişehir Osmangazi University Faculty of Medicine, Eskişehir, Turkey (Aİ)
ORCID IDs of the authors: M.Y. 0000-0002-2058-3253; A.J. 0000-0002-4125-4053; P.M. 0000-0002-5859-7386; J.P. 0000-0001-7886-6283; B.B. 00000002-3974-1514; T.T. 0000-0001-7853-2179; T.L. 0000-0001-5187-3010; J.D. 0000-0002-3034-378X
Cite this article as: Yung M, James A, Merkus P, Philips J, Black B, Tono T, et al. International Otology Outcome Group and The International Consensus on The Categorization of Tympanomastoid Surgery. J Int Adv Otol 2018; 14(2): 216-26.

The International Otology Outcome Group (IOOG) was founded in 2017 to encourage and facilitate international collaboration with regard to thesurgical outcome of ear surgery. This report outlines the methodology and recommendations of the consensus-based categorization of tympanomastoid surgery produced by the IOOG. The IOOG Steering Committee used the acronym SAMEO-ATO to categorize tympanomastoid operations,representing the stage of surgery, approach, mastoid bone extirpation, external bony wall repair, obliteration of the mastoid cavity, access to the
middle ear, tympanic membrane reconstruction, and ossicular reconstruction. A modified Delphi technique was used to obtain international consensus. The expert panels included the chairpersons from 21 otology societies. The approval rate of the SAMEO-ATO system from the otology societies
was 95%. The SAMEO-ATO scheme was presented at the 31st Politizer Meeting for field testing. There were no objections or serious concerns raised.
Some international otologists wished to see more surgical categories included to reflect the varieties of surgical techniques, but they accepted that it
would make the whole system cumbersome. In addition to providing an international categorization of tympanomastoid surgery, the IOOG Steering
Committee plans to introduce a common otology dataset that the international otology community could use to record their surgical outcome. The
high level of international consensus on the IOOG categorization of tympanomastoid surgery supports this tool for surgeons to pool their surgical
data into a large database for research and comparative audit.
KEYWORDS: International, consensus, classification, mastoidectomy, middle ear surgery

INTRODUCTION
There is a paucity of high-level evidence regarding the surgical management of cholesteatoma. This is in part due to a lack ofrandomized controlled studies in the field of tympanomastoid surgery, as more readily achievable study designs are prone tobiases that may not be easily overcome: for example, allocation, observer, and selection bias. Surgeons inevitably select what they
consider to be the optimum surgical intervention, based on the varying degrees of factors such as their experience, resource availability, and assessment of individual patient circumstances. Consequently, published appraisals of outcomes from different surgicalinterventions rely to a large extent on comparison between different surgeons and different institutions. Unfortunately, there is noconsensus on the nomenclature of surgical procedures, thus making such comparisons unreliable [1].
In 2017, the European Academy of Otology and Neurotology (EAONO) and the Japan Otological Society (JOS) produced a “Joint
Consensus on Definitions, Classification and Staging of Middle Ear Cholesteatoma”. Via consultation with the international otology
Corresponding Address: Matthew Yung E-mail: matthewyung@btconnect.com

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Submitted: 27.04.2018 • Accepted: 16.05.2018 • Available Online Date: 03.08.2018©Copyright 2018 by The European Academy of Otology and Neurotology and The Politzer Society - Available online at www.advancedotology.org

Yung et al. Categorization of Tympanomastoid Surgery

community, it has become clear that there is great need for common
otology data fields that surgeons can collect systematically for comparative audit and research [2]. In 2017, the International Otology Outcome Group (IOOG) was established to address these issues (www.
IOOG.net).
The initial IOOG focus was on the development of a new classification of tympanomastoid surgery, as this is performed commonly bymost otologists and comprises a wide range of different techniques.
The primary aim was to develop a classification system that would
encompass all aspects of a surgical technique that are likely to influence the outcome of tympanomastoid surgery. A pre-requisite
was to describe interventions using unambiguous nomenclature, toencourage a uniform manner or reporting, and categorize them in asystem that would be acceptable to otologists and neuro-otologists
internationally by employing a simple, logical, and user-friendly format. This report outlines the principles used to devise the new classification, including use of the Delphi method to ascertain international acceptance [3].
Formulation of the International Consensus on the “Categorizationof Tympanomastoid Surgery”
The IOOG Steering Committee recognized that there is a wide variety of surgical techniques employed by surgeons all over the world.
Many of these are “hybrid operations,” for example, creating a window in the scutum, front-to-back mastoidectomy, and exclusion of
the mastoid cells remnant using cartilage or soft tissue grafts. It was
not the intention of the Steering Committee to produce a coding
book for surgery. Surgeons are advised to exercise their judgment byplacing their surgical procedure into the best-fitting category within
the IOOG categorization to aid international comparison, therefore
reducing confusion. The IOOG Steering Committee has produced auser guide to aid explanation.

“PORP” and ”TORP” were deliberately omitted. The IOOG Steering
Committee advises that the SAMEO-ATO scheme should be used asa whole rather than in parts, as the terms “stage of surgery” and ”approach” are universally applicable to middle ear operations.
In anticipation of the consensus exercise, the IOOG Steering Committee pre-determined 80% or above as the threshold criteria required
to fulfill international consensus. This paper describes the SAMEOATO scheme and the methodology on how the IOOG Steering Committee arrived at the final version.
The IOOG international consensus on the categorization of tympanomastoid surgery was based on two cycles of consensus surveys anda field test (Figure 1). The categorization consists of the SAMEO-ATO
schemes (Figures 2 and 3) and two schematic drawings that depict
the different categories of “Mastoidectomy” and “Ossicular Chain”(Figures 4 and 5). The SAMEO-ATO scheme is complimented by a user
guide for explanation and illustration (Appendix 1).
International Consensus Survey Round 1 (Draft 1)
Draft 1 of the categorization document (SAMEO-ATO) was the resultof many rounds of discussion and refinement amongst the membersof the Steering Committee.
International feedback was sought from international otology societies rather than individuals. Initially, an email in English was sent to thechairpersons of 44 otology societies within the IOOG address bookto establish a relationship and to validate the email address contact.
There is no an official national otology society for Belgium and theNetherlands. Instead, there is a Dutch–Belgian Otology Group witha. Consensus on mastoid operations
To minimize ambiguity, the IOOG Steering Committee used terms
that describe what the surgeon does rather than historical terminologies that are open to personal interpretation. For this reason, terms
such as “modified radical mastoidectomy,” “radical mastoidectomy,”and “tympanoplasty” were deliberately abandoned.
The IOOG Steering Committee tried to make the description of thesurgical procedure compatible with ICD-10 if possible. The label“Mastoidectomy with removal of the bony canal” was used instead of“Canal wall down mastoidectomy”; “Mastoidectomy with canal wall
preserved” was used instead of “Canal wall up mastoidectomy.”
The IOOG Steering Committee used the acronym SAMEO to categorize mastoid bone operations, representing the stage of surgery,approach, mastoid bone extirpation, external bony wall repair, andobliteration of the mastoid cavity.
b. Consensus on middle ear operations
The IOOG Steering Committee used the acronym ATO to categorize middle ear operations, with this representing the access to the
middle ear, tympanic membrane reconstruction, and ossicular reconstruction. To allow compatibility with ICD-10, the label “repair of
tympanic membrane” was used instead of ”myringoplasty.” The terms

Figure 1. Participants involved in the consensus methodology of the “IOOG
categorization of tympanomastoid surgery”.

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Figure 2. The IOOG SAMEO scheme of the SAMEO-ATO framework

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one Dutch representative and one Belgian representative. For the
purpose of this consensus process, the Dutch Otology Group and theBelgian Otology Group were treated as two separate otology societies. Twenty-five out of 44 societies responded. It is possible that theemails sent to others did not reach the intended person due to theuse of an outdated email address, or they might have been rejected
due to language barriers.
The draft SAMEO-ATO scheme, user guide, and the diagrams weresent to the 25 willing chairpersons accompanied by a survey ques-

Figure 3. The IOOG ATO scheme of the SAMEO-ATO framework219

J Int Adv Otol 2018; 14(2): 216-26

Figure 4. Schematic illustration of the IOOG categorization of “mastoidectomy”.

220Yung et al. Categorization of Tympanomastoid Surgery

Figure 5. Schematic illustration of the IOOG categorization of “ossicular reconstruction”.

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Figure 6. Summary poster of the IOOG SAMEO-ATO scheme for categorization of tympanomastoid surgery

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Yung et al. Categorization of Tympanomastoid Surgery

tionnaire (Appendix 2). The responders were encouraged to provide
approval or disapproval to each recommendation and were further
invited to provide comments or suggestions regarding each elementof the SAMEO-ATO scheme. All of the societies were given a periodof 2 months to allow each chairperson time to consult their councils.
A prolonged consultation period would risk interrupting the consensus cycles as the chairpersons and council members might leave
office before the second cycle is completed. Therefore, the principal
author (MWY) acted as the facilitator in this consensus process to ensure that the procedure was conducted efficiently.

2.

3.

Of the 25 otology societies contacted, 18 gave their responses during
Round 1. They were the otology societies from Brazil, Czech Republic, Denmark, Germany, Hong Kong, Hungary, Iran, Italy, Japan, theNetherlands, Romania, Russia, South Korea, Slovenia, Sweden, Switzerland, the United Kingdom, and the United States of America.
During Round 1, all of the chairpersons agreed that there is a need for
an international consensus on the categorization of tympanomastoid procedures. Seventeen out of the 18 responders gave approvalto the SAMEO-ATO scheme proposed by IOOG, and one disapproved.
All 18 responders indicated that they will encourage the use of the
SAMEO-ATO scheme for the categorization of tympanomastoid surgery following launch.

Steering Committee made changes to the wordings to makethem clearer to the users.
Mastoidectomy with preservation of the bony canal combinedwith atticotomy was not represented: The IOOG Steering Committee added a new category within the revised document(Draft 2) to address this.
Level of detail within the SAMEO-ATO scheme: Conflicting
comments were received. Some societies wished to have more
sub-categories, such as materials of reconstruction, nature ofrevision surgeries (previous surgery performed in same institution versus elsewhere), the use of active middle ear implants, etc.
Other societies advised a more minimalist approach to allow thesystem to be simpler and more user-friendly. The IOOG decided
to take a balanced view and to keep the categorization simple
without losing the distinction between important categories. In
addition to the Categorization of tympanomastoid surgery, the
IOOG intends to produce a common otology dataset for the purpose of comparative audit as a follow-up project. The comments
and suggestions received during the consensus exercise will
help in the design of this dataset.

The level of approval of each section of the SAMEO-ATO scheme together with selected comments from 18 otology societies in Round
1 are listed in Table 1.

International Consensus Survey Round 2 (Draft 2)
Despite a high level of approval of SAMEO-ATO during the first roundof the consensus survey (17/18 approval; 1/18 disapproval), the IOOG
Steering Committee used the feedback to improve the document.
The main change was to insert a category that represents “Mastoidectomy with preservation of the external ear canal in combination
with atticotomy.’”The comments received can be categorized into three main themes:
1. Semantic changes: Based on some of the feedback, the IOOG

The revised SAMEO-ATO scheme (Draft 2) with supporting documents and diagrams was sent again to the chairperson of the 25 otol-

Table 1. The level of approval and comments on Round 1 of consensus survey on the SAMEO-ATO scheme from 18 otology societies (Brazil, Czech Republic,
Denmark, Germany, Hong Kong, Hungary, Iran, Italy, Japan, the Netherlands, Romania, Russia, South Korea, Slovenia, Sweden, Switzerland, the United
Kingdom, the United States)
Stage

Approach

Mastoidectomy

Ext Ear Canal

Obliteration

AccessTym Memb

Approval

17 Yes (94%)
1 No

17 Yes (94%)
1 No

17 Yes (94%)
1 No

17 Yes (94%)
1 No

17 Yes (94%)
1 No

16 Yes (94%)
16 Yes (94%)
1 abstain 1 No 1 abstain 1 No

Comments
Given

Specify if rev
alone or withsomeone else;
Identify numberof previous op

Considered
combination
endoscopeand incision;
Preferred“transcanal topermeatal”;
The societythat objected
insisted that
endural orendoscopic
approach has
no place inmastoidectomy.

Like to specificfront-to-back Vs
back-to-front;
Questions if
atticotomy
is CWU or CWD;
Suggest Mod R
Mastoid and R
Mastoid in separate
categories.
The society that
objected favoredusing front-to-back Vs
back-to-front
mastoidectomy, andinclude cortical Vs
extended cortical
mastoidectomy into
the system.

Distinguishinflammatory Vs
congenital atresia;
Question if
scutumplasty+
atticotomy should
be CWU or CWD;
Suggest fascia orother soft tissue
graft group
together.
The society that
objected felt there
is too much overlap
between external
canalreconstruction andobliteration.

Like to see more
Wish morecategories on
clarity of A2
specific technique; and A3
Define partial Vs
total oblit;
Reduce repetitionin sub-categories
between M and O.
The society that
objected wisheddetail of
obliteration
technique ormaterials used tobe listed.

Wish to see morecategories on
specific
techniques andgraft materials;
Define partial
graft, subtotal,
and total
perforation;
Suggest a
sub-category on
concomitant VT.
The society that
objected wisheddetail oftechnique andmaterial ofeardrum graft tobe listed.

Ossiculoplasty
17 Yes (94%)
1 NoWish a subcategory on
active middle
ear implant.
The society that
objected wisheddetail oftechnique andmaterial of
ossiculoplasty to
be listed.

Ext: external; Tym Memb: tympanic membrane; rev: revision; op: operation; Mastoid: mastoidectomy; CWU: canal wall up; CWD: canal wall down; Mod R Mastoid: modified radical mastoidectomy; R:
radical; Oblit: obliteration; VT: ventilation tube

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ogy societies for Round 2 of the consensus survey. The comments
received from all the otology societies at Round 1 were anonymized
and categorized into themes. They were sent along with Draft 2 toall the chairpersons in compliance with the Delphi method. Again, aconsultation period of 2 months was provided to each society.

any further changes to the SAMEO-ATO scheme but have updated the user guide to clarify some of the expressed confusion. The
suggestions received have been helpful for the construction of thecommon otology dataset that the IOOG Steering Committee is currently working on.

Out of 25 otology societies, 21 gave their responses in Round 2. The
otology societies in Belgium, Canada, and India gave their full approval in Round 2, even though they missed the deadline in Round 1. For
Round 2, the responders were the otology societies from Belgium,
Brazil, Canada, Czech Republic, Denmark, Germany, Hong Kong, Hungary, India, Iran, Italy, Japan, the Netherlands, Romania, Russia, South
Korea, Slovenia, Sweden, Switzerland, the United Kingdom, and theUnited States of America. There were fewer comments received fromthe various otology societies in round 2. The comments from theAmerican Otological Society were mixed. They felt that there is noneed for a new classification, as historical terminologies are sufficient
for reporting. Nevertheless, they were happy with the description
and accuracy of the SAMEO-ATO scheme. They were concerned thatthe complexity of the system may discourage routine use by busy
clinicians. As such, they are reluctant to recommend the SAMEO-ATO
scheme to be mandatory for the reporting of surgical outcome intheir official journal Otology and Neurotology.

In summary, 20 out of 21 (95%) responding otology societies haveprovided full approval to the SAMEO-ATO scheme in Round 2. This
exceeds the level of 80% set in the beginning of this process. At thisstage, the IOOG Steering Committee decided to conclude the consensus stage, and to take the SAMEO-ATO scheme to a “field test.”

The comments received by the IOOG Steering Committee during
Round 2 are listed in full rather than grouping them into themes(Table 2). The single society who expressed disapproval during
Round 1 provided approval at Round 2. The only disapproval received in Round 2 was from the Dutch otology group regarding“Ear canal wall reconstruction.” They suggested deleting the statement regarding “air behind graft,” as it was considered to leadto confusion. After deliberation, the IOOG Steering Committee
decided to retain this statement, but to revise the wording from“air behind graft” to “space behind graft.” Encouraged by the highdegree of consensus, the IOOG Steering Committee did not makeField Test (Draft 3)
Field testing of the SAMEO-ATO scheme for the “Categorization of
tympanomastoid surgery” was acquired at the 31st Politzer Society
Meeting in Gran Canaria on February 23rd, 2018. The aim of the fieldtest was to identify the areas of potential ambiguity and/or dispute.
Ninety-four international delegates attended the scientific session on
the ‘Consensus on the International Categorisation of tympano-mastoid operations’. Each delegate was provided with a printed handoutof the SAMEO-ATO scheme together with diagrams. Comments fromthe delegates were noted and are listed in Table 3. Several comments
were from delegates seeking clarification regarding various categories. There was no common concern regarding any particular aspectof the SAMEO-ATO scheme. The Steering Group was mindful that any
significant change to the document could invalidate the consensus
provided by the otology societies. It was reassuring that the field test
did not identify any significant area of dispute or controversy.
Several delegates requested more details regarding the surgical procedures included within the SAMEO-ATO scheme, but they acceptedthat it would make the system too complicated and less user-friendly.
There was a discussion regarding how to categorize reconstruction
between the malleus and footplate in the presence of a stapes suprastructure. There was general agreement that this should be rep-

Table 2. The level of approval and comments on Round 2 of consensus survey from 21 otology societies (Belgium, Brazil, Canada, Czech Republic, Denmark,Germany, Hong Kong, Hungary, India, Iran, Italy, Japan, the Netherlands, Romania, Russia, South Korea, Slovenia, Sweden, Switzerland, the United Kingdom,
the United States)
Stage

Approach

Mastoidectomy

Ext Ear Canal

Obliteration

AccessTym Memb

Ossiculoplasty

Approval

21 Yes (100%)

21 Yes (100%)

21 Yes (100%)

20 Yes (95%)
1 No (5%)

21 Yes (100%)

21 Yes (100%)

21 Yes (100%)

21 Yes (100%)Comments
Given

Specify if rev op
on own cases Vs
elsewhere.

Query the term
Make distinction
Some overlap here Acronym of E and“approach” as it
between “Mod R
with O; Suggest
O are confusing.
has different
Mastoid”Vs “R Mastoid”; adding “/Partial” tomeaning toConsider category for “Ext Ear Canal” in“incision”;
Intact Bridge Mastoid; heading; Need
Should distinguish Question how toclarification on“front-to-back”Vs classify “making aterminologies “soft”“back-to-front”
window in scutum”;
Vs “rigid.” Suggest
Mastoid+
Suggest adding
deleting the“endoscopic”Vs “/Partial” to “Mastoid” statement about“microscopic
in heading;“air behind graft.”surgery”
Question how “disease
destruction oflabyrinth” should beclassified.

More categories
Termbased on graft“columellar”
materials;
should be
Add a category on reserved forcompletely absent TORP only.
of annulus.

Ext: external; Tym Memb: tympanic membrane; rev: revision; op: operation; Mast: mastoidectomy; CWU: canal wall up; CWD: canal wall down; Mod R Mastoid: modified radical mastoidectomy; R: radical;
Oblit: obliteration; TORP: total ossicular replacement prosthesis

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Table 3. Questions and comments received from international delegates on the IOOG international consensus on the categorization of tympanomastoid
surgery and the responses
Country of Work

Question/Comment

Action Taken by the IOOG Steering GroupNew Zealand

How to categorize TORP in the presence of stapes

General agreement that is Ofm or Oft.
Will make this clearer on a diagram

UK

Can SAMEO-ATO be used retrospectively?

Depends on how detailed the original dataset is. Best is prospectively.
The IOOG Steering Group members will try to retrospectively
categorize their own surgery and present that in a report

Spain

Clarification on terminologies under “Approaches”

Reinforce A1 and A2 involve no external incision;
Will make “Endoscopic” and “Microscopic” more prominent under thetranscanal approach

USA

Suggest use term “removal” and “preserved” instead of CWU
and CWD to make it more compatible with ICD-10

General agreement on the suggestion and changes will be made to
the terminology.

UK

Make a distinction between “subtotal” and “total” TM repair.

Difficulty to define total perforation based on amount of annulus
present. Such distinction can be included in the data field set rather begiven a separate category

BelgiumOvt is a dangerous procedure and should not be performed.

The current scheme is not designed to teach surgeons what to do.

CanadaMake a separate category under O for total removal offootplate—by accident or by design at surgery.

Most delegates agreed that there is no need to include Ovd as it isextremely rare.
Total stapedectomy with soft tissue graft could be included in the data
field set rather than given a separate category

FranceClarify if cartilage plate/sheet over stapes head Ost or Osd.

Osd: If the cartilage strut is inserted between eardrum and stapes,
then it is Ost.

Belgium

Why is middle ear pathology not featured?

The categorization is only for surgical procedure. The IOOG is working
on minimal data fields that include all risk factors of chronic ear surgery.

UK

What about including procedures for complications?

These are rare, and their inclusion will make the system too complicated.

TM: tympanic membrane; Ofm: ossicular reconstruction between the footplate and malleus; Oft: ossicular reconstruction between the footplate and tympanic membrane; Ovd: tympanic membrane directly placed over an open vestibule directly; Ost: ossicular reconstruction between stapes and tympanic membrane; Osd: tympanic membrane directly placedon the stapes head)

resented as Ofm. The IOOG Steering Committee has now introduced
labeling on the relevant diagram to clarify this.
The delegates were asked to give a show of hands at the end of thesession. Sixty persons indicated approval of the SAMEO-ATO scheme,
and none indicated disapproval.
The international consensus on IOOG categorization of tympanomastoid surgery and user guide is presented in Figures 2–5. The IOOG
Steering Committee also provides a poster summary of the scheme
for users to display in their operating room (Figure 6).
After the launch of the categorization of tympanomastoid surgery,the IOOG Steering Group will organize a multi-center study to measure how well the SAMEO-ATO scheme is holding up.
DISCUSSION
The primary aim of IOOG was to develop an internationally approved
categorization of tympanomastoid surgery that would encompass
all aspects of surgical technique. This could provide the basis for surgeons to pool their surgical data into a large database for research
purpose. There are a number of historical classifications for middle
ear and mastoid surgery in the literature.1 A recent systematic literature review showed that many of these systems are outdated or

incomplete; most are not widely accepted and only few correspondwith all current surgical techniques. IOOG decided to produce a system based on international consensus.
Much consideration was given to get maximum international representations in the consensus process. The members of the IOOG Steering Committee were from seven countries. The expert group or raters
were the representatives or chairpersons of 21 otology societies. The
reason for inviting the chairpersons as members of the expert group
was because they are the experts and can help in the eventual dissemination of the scheme amongst the members of the societies. In
order to facilitate the analysis of the survey responses from each society through its representative, binary response was sought on eachquestion rather than on a Likert scale.
The design of the SAMEO-ATO system is to make it compliant with
the ICD-10 coding system and avoid using historical terminologies
that are often confusing [1]. The SAMEO-ATO system incorporates
modern surgical techniques such as ‘endosopic approach’ and thetechniques of mastoid cavity reconstruction.
The Delphi technique was chosen for the consensus methodology
because it allows time for each chairperson to consult the council
members of each society. This could not be done with the Nominal

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Group Technique. The Delphi technique also has the advantage ofanonymity and thus avoids dominance by certain groups. The highinternational approval rating of over 90% on the IOOG SAMEO-ATO
scheme supports its use as the international categorization of tympanomastoid surgery.

Financial Disclosure: The authors declared that this study has received nofinancial support.

Peer-review: Externally peer-reviewed.

REFERENCES

Author contributions: Concept – M.Y.; Design – M.Y., A.J., P.M., J.P., B.B., T.T.,
T.L., J.D.; Supervision – M.Y., A.J., P.M., J.P., B.B., T.T., T.L., J.D.; Resource – T.T.; Materials – N.A.; Data Collection and/or Processing – M.Y., A.J., P.M., J.P., B.B., T.T.,
T.L., J.D.; Analysis and/or Interpretation – M.Y., A.J., P.M., J.P., B.B., T.T., T.L., J.D.;
Literature Search – A.İ.; Writing – M.Y., A.J., J.P.; Critical Reviews – P.M., T.T.
Acknowledgements: The authors would like to thank Dr. Akira Ganaha for theillustrative art work in this paper.
Conflict of Interest: The authors have no conflict of interest to declare.

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You can reach the appendix of this article athttps://doi.org/10.5152/iao.2018.5553

1.
2.

3.

Merkus P, Kemp P, Ziylan F, Yung M. Classifications of mastoid and middle
ear surgery: A scoping review. JInt Adv Otol 2018; 14(2): 227-232.
Yung M, Tono T, Olszewska E, Yamamoto Y, Sudhoff H, Sakagami M, etal. EAONO/JOS joint consensus statements on the Definitions, Classification and Staging of Middle Ear Cholesteatoma. J Int Adv Otol 2017; 13:
1-8. [CrossRef]
Humphrey-Murto, Susan MD, MEd, FRCPC; Varpio, Lara PhD; Wood, Timothy J. PhD; Gonsalves, Carol MD, MMed; Ufholz, Lee-Anne MLIS; Foth,
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J Int Adv Otol 2018

Appendix 1. Explanatory notes on the IOOG categorization of tympanomastoid surgery
1.

The aim of the SAMEO-ATO categorization is to aid the comparison of surgical outcome from middle ear and mastoid surgery
between institutions.

2.

SAMEO-ATO is an acronym that outlines the subgroups of mastoid and middle ear surgery that comprise the classification system:
Stage of operation
Approach
Mastoidectomy procedure 		External auditory canal reconstruction			
Mastoid Surgery
Obliteration of mastoid cavity		
Access					Tympanic membrane (TM) repair				Middle ear surgery
Ossicular chain repair			

3.

4.

5.

6.

Where possible, terminology in the SAMEO-ATO system is derived from descriptors used in ICD-10-PCS (see www.icd10data.
com/ICD10PCS/Codes/0/9). To minimize ambiguity, terms describe what the surgeon does rather than historical nomenclature that may be open to variable interpretation. For this reason,
procedures are not grouped by terms such as “atticotomy” (seealso below), “modified radical mastoidectomy,” “radical mastoidectomy,” and “tympanoplasty.” Nevertheless, common names
such as these are included in brackets to facilitate understanding.
The IOOG Steering Committee recognizes that there is great
variation in surgical techniques used by surgeons all over theworld. The Committee has aimed for a balance in the SAMEOATO system between simplicity and over-complexity to provide
a usable classification that includes the parameters that distinguish important differences in surgical intervention. Surgeons
that perform a procedure that they consider to be significantly
different from any of the categories defined by the SAMEO-ATO
are encouraged to allocate their procedures to the closest fit.
Details of any such differences should be recorded separately togenerate data than can be used to stimulate future revisions of
the SAMEO-ATO system.
Other important parameters that might influence the outcome,including patient-related variables, complications of disease orsurgery, and further surgical details such as the nature of previous surgery, grafting materials, concomitant use of ventilation
tube and active middle ear implants, are beyond the scope of
this surgical classification. The IOOG Steering Committee isdeveloping a common dataset for middle ear surgery to use
alongside the SAMEO-ATO system that will include such topics.
Of course, additional parameters may be recorded by individual
surgeons, but this should not compromise allocation of procedures into the SAMEO-ATO categories.
The SAMEO-ATO system has been developed for implementation in prospective data collection. Although it may be possible
to apply the system retrospectively, the accuracy of classification
will be impaired significantly by the limits of previously collected7.

data fields. Users should report whether the system has been applied prospectively or retrospectively and emphasize potential
discrepancies from retrospective use.
The IOOG Steering Committee does not advocate any particular surgical procedure or combination of procedures that may
be defined by the SAMEO-ATO classification but has simply attempted to derive a comprehensive classification system. An
example raised during consensus discussions was that ossiculoplasty type Ovt might be dangerous so arguably should not be
performed, but it remains in the classification for completeness.

Guidance on implementation of the SAMEO-ATO categorization in
tympanomastoid surgery
These notes provide guidance on use of the SAMEO-ATO system. The
IOOG advises that surgeries be categorized using all componentsof the SAMEO-ATO, not limited just to the parts of surgery that arecompleted (e.g., the absence of any mastoid surgery is categorized
as MxExOx). “Stage of surgery” and “Approach” are applicable to both
middle ear and mastoid operations.
• Stage of operationi. S1 signifies the first surgery for the condition being
treated.
• For example, first operation for cholesteatoma after a previous TM perforation repair
ii. S2 signifies any subsequent surgery for that condition, not the number of operations completed• For example, third surgery for a recurrenceof cholesteatoma after two planned stagesof surgery is coded as S2r• Approachi. If an incision is used to access the mastoid, the useof an endoscopic surgery is considered to be an adjunct procedure• for example, post-auricular incision used forendoscopic access to the mastoid is A4, even
if no microscope is used
ii. If an external incision is made for harvest of a graft
but not used for access to mastoid or middle ear,this is classified as A1 or A2.
iii. The term “permeatal approach” is considered to besynonymous with “transcanal approach.”
Mastoid Surgery• Mastoidectomy procedurei. An M1 procedure is a mastoidectomy leaving thecanal wall intact (preserved), and an M2 procedure
is a mastoidectomy with the removal of the canalwall partly or completely.
ii. M2a: As part of the canal wall is removed with theremoval of the scutum (atticotomy), this procedure
is categorized according to the SAMEO-ATO withother “canal wall down” surgeries. However, many
surgeons incorporate an atticotomy and scutumreconstruction with a cortical mastoidectomy inwhat is considered to be “canal wall up” surgery. Thishybrid procedure is defined in the SAMEO-ATO by
combining the mastoid codes for cortical mastoid-

Yung et al. Categorization of Tympanomastoid Surgery

ectomy and scutum removal (e.g., M1a,2a or M1b,2a if
posterior tympanostomy is included).
iii. Partial scutum removal to create only a window at
the scutum (for access to the epitympanum)while
preserving its inferior border is also to be classified
as M2a.
iv. M3a differs from M2c in that the cavity is closed offcompletely with an ear canal closure (removal of all
ear canal skin and TM), as well as blocking up of the
tympanic opening of the Eustachian tube.
• External auditory canal reconstruction
i. Different materials may be used to reconstruct the
scutum and/or bony canal wall with the intentionof leaving a ventilated attic and mastoid under thegraft.
• E1 Soft tissues include fascia, perichondrium, pericranium,
periosteum, and some bio-engineered grafts (e.g., porcine collagen or cadaveric human skin derivatives)• E2 Hard reconstruction includes cartilage, bone, or solid prosthetic materials (e.g., titanium, hydroxyapatite).
ii. If an obliteration is added to the canal wall procedure, the reconstruction of the ear canal prior obliteration can be noted under E.
iii. Surgeons should still record material for reconstruction in their own database in addition to the
SAMEO-ATO system.
• Obliteration of mastoid cavity
i. Ox means that an empty air space is present behindthe ear canal or in the cavity.
ii. Partial obliteration spares the attic cavity+part ofthe mastoid cavity (i.e., just a reduction of the cavitysize). A total obliteration is a complete obliterationof the whole mastoid and the attic cavity.
iii. Obliteration of the attic without obliteration of the
mastoid is considered to be O1.
iv. The type of obliteration material can be added towith small letters in own database and should bereported when presenting a series.
Middle Ear Surgery• Access
i. The distinction between A2 and A3 is that in A3, there
is an absence of the meatal skin to line the ear canal,
for example, during surgery for medial canal fibrosis.
ii. This Access category has not been developed forthe congenital meatal atresia surgery.

• TM repair
i. Tn 		 TM normal, no need for surgery
ii. Tx		 TM not normal, but not repaired• e.g., atelectatic TM elevated but not reconstructed; perforation
present, but surgeon chose not to repair; or previous cartilage
tympanoplastyiii. T3 Total perforation is defined as complete absenceor removal of the TM and annulus. Subtotal perforation is the absence of TM, but the annulus is stillpreserved.
• Ossicular chain repair• On Normal ossicular chain. Ossicular repair not needed• Ox Ossicles not normal, but no ossiculoplasty performed
i. It should be noted that the ossiculoplasty diagrams
are conceptual and not a surgical illustration oftechnique. The stapes superstructure is shown in
faded outline (Ofm and Oft) to indicate that a reconstruction can be performed whether superstructureis absent or present.
ii. Categories of ossiculoplasty are defined by the furthest points of contact of the graft or prosthesis between these anatomical structures:• m malleus handle
TM
• t
• i
incus
superstructure of stapes• s• ffootplate of stapes• v vestibule (no distinction is made between footplate perforation, footplate removal, or placement of a soft tissue
		 graft, although these differences may
be recorded for presenting/reporting on thedataset)• d direct coupling of TM without a graft or
prosthesis
		(e.g., Osd is myringostapediopexy)iii. Regarding cartilage tympanoplasty with absent incus but intact stapes:• Osd Flat cartilage graft used in TM reconstruction in contact
with stapes (cartilage myringostapediopexy)• Ost Shaped piece of cartilage placed as a bridge between stapes and TM
iv. Placement of a silastic band around the stapes superstructure and the shaft of a total ossicular replacement prosthesis between footplate and TM is
included within Oft and Ofm.

J Int Adv Otol 2018

Appendix 2. Survey Questionnaire
The International Otology Outcome Group wishes to get an international consensus on the categorization of tympanomastoid surgery. Thisis the first step toward starting an international audit of surgical outcomes in chronic otitis media. It will help us if you can give your approval/
disapproval of the SAMEO-ATO system designed by members of the Steering Group. Please answer yes or no on the following questions. If
you disagree, please give your reasons and suggestions for improvement. Please put yes or no and any comment for each question. We like tohave one response from each otology association.
1.

Do you think there is a need for an international consensus on the definition and categorization of tympanomastoid surgery?
Yes / No ……………………………………….
Comment……………………………………….

2.

Do you approve the description of the mastoidectomy procedure using the system of SAMEO (stage of surgery, approach, mastoidectomy, external ear canal reconstruction, and obliteration)?
Yes / No ……………………………………….
Comment……………………………………….

3.

Do you approve the description of the tympanoplasty procedure using the system of ATO (access to middle ear, tympanic membrane reconstruction, ossicular chain reconstruction)?
Yes / No ……………………………………….
Comment……………………………………….

4.

Do you approve the description under S?
Yes / No ……………………………………….
Comment……………………………………….

5.

Do you approve the description under A (Approach in Mastoidectomy)?
Yes / No ……………………………………….
Comment……………………………………….

6.

Do you approve the description under M?
Yes / No ……………………………………….
Comment……………………………………….

7.

Do you approve the description under E?
Yes / No ……………………………………….
Comment……………………………………….

8.

Do you approve the description under O (Obliteration)?
Yes / No ……………………………………….
Comment……………………………………….

9.

Do you approve the description under A (Access to Middle Ear)?
Yes / No ……………………………………….
Comment……………………………………….

10.

Do you approve the description under T?
Yes / No ……………………………………….
Comment……………………………………….

11.

Do you approve the description under O (Ossicular Chain Reconstruction)?
Yes / No ……………………………………….
Comment……………………………………….

12.

Would you recommend the members of your society to use this in recording their operations?
Yes / No ……………………………………….
Comment……………………………………….