1. 気管軟化症とEDAC
Tracheobronchomalacia
and
Excessive Dynamic Airway Collapse

2. TBM と EDAC
Respirology (2006) 11, 388–406
TBM; Tracheobronchomalacia
気管軟骨, その周辺の筋, 弾性線維の脆弱化.
気管狭窄を来たし, 気管分泌増加, 咳嗽, Wheeze,
再発性気管支炎, 肺炎を生じる病態.
EDAC; Excessive dynamic airway collapse
気管軟骨に被われていない気管背側の弾性膜の脆弱化.
前後方向に気管支が圧排され, 狭窄を来す.
COPDや肺気腫, 喘息, TBMに伴うことが報告されている

3. D 前方の気管支軟骨の脆弱化 Respirology (2006) 11, 388–406
著明な三日月型となる.
C EDAC B 生理的呼気状態.
前後径が>50%縮小する場合 通常前後径は35%[11-61]縮小する
E 気管軟化症
左右径が縮小し, 剣の 状となる(Saber-sheath type)

4. 気管の生理学
通常気管は吸気時に拡張する.
胸腔内が陰圧になる事で, 気管壁は伸展される.
その際気管壁の平滑筋は緊張し, 拮抗する
呼気時は胸腔内が陽圧となり, 気管内腔は縮小する.
その際気管壁の平滑筋は気管壁を維持するが,
機能不全があると軟骨の無い後壁が貫入する → EDAC.
気管軟骨が脆弱であれば, 軟骨部が貫入する → TBM.

5. TBM, EDACの頻度
Respirology (2006) 11, 388–406
Curr Opin Pulm Med 2009;15:113–119
後天性TBMの頻度は気管支鏡施行例の4.5%
COPDで気管支鏡した分の23%, 慢性気管支炎の44%.
日本国内における, 4283例の気管支鏡施行例では,
50-100%の狭窄出現したのは12.7%.
その内 72%は50-80yの高齢者であった.
75-100%の高度狭窄例は3.1%

6. EDACの頻度は報告により様々
咳嗽時に気管径が>50%縮小するのは,
3wk以上の慢性咳嗽で気管支鏡を施行した群の14.1%
他の原因は, 喘息58.9%, 後鼻漏 57.6%,
GERD 41.1%, 気管拡張症 17.9%
CHEST 1999; 116:279–284
COPD100例のProspectiveの評価では,
EDACは20%で認められた.
母集団の年齢 65±7歳, FEV1 64±22%
EDACの有無で呼吸機能, 自覚症状に差は認めなかった.
Chest 2012;142:1539-1544

7. TBM, EDACの原因
Respirology (2006) 11, 388–406
TBMは小児期発症する先天性のタイプと,
中年∼高齢者で発症する続発性のタイプがある.
小児期では元々気管が細いため,
再発性の咳嗽, 呼吸困難, 呼吸器感染症を来すが,
気管が広くなり, 組織が強固となる学童期には消失.
続発性はTBM, EDAC双方あり, 中高年で多く, COPDや喘息,
挿管による刺激, 気管切開後に生じる事が有名.
長期間の人工呼吸器管理(PEEP)も原因となり得る.

8. 他の後天性の原因 Respirology (2006) 11, 388–406
胸部の閉鎖性外傷,
長期間の喫煙, COPD, 肺気腫, 喘息, 慢性炎症
悪性腫瘍; 肺癌や甲状腺癌による気管支壁破壊
機械的因子; 胸部手術など.
慢性的な気管圧迫; 胸骨下甲状腺腫, 胸腺腫, 動脈瘤
先天性気管支拡張; Mounier-Kuhn syndrome
先天性の気管弾性線維の欠如, muscularis mucosa消失
Ehlers-Danlos syndrome
甲状腺疾患; 腺腫による慢性の圧迫.
Endobronchial electrosurgery

9. TBM, EDACの診断
Respirology (2006) 11, 388–406
繰り返す呼吸苦, 呼吸感染症, Wheeze,
抜管失敗例などで疑う.
Wheezeは全体の51%, 喘息様発作は17%でのみ認める.
通常喘息の治療であるステロイドや
気管拡張薬吸入の効果は乏しい.
血痰は認め得るが, 3.5%のみ.
非喫煙者の慢性咳嗽のうち, 最多の14.1%を占める原因.

10. Respirology (2006) 11, 388–406
TBMやEDACでは進行する高CO2血症,
呼吸不全を呈することもあり, その場合挿管となる
しかしながら挿管患者で上記を診断するのは難しい.
挿管チューブがステントの役割を担う点,
PEEPが気管支虚脱をマスクする可能性がある点.
上記例で改善し, 抜管した直後にWheeze, 呼吸苦出現し,
再挿管となる例も多い.
→ 繰り返す抜管失敗もTBM, EDACを疑うヒント.

11. 2. Electron beam 1. Short scanning time of only 50–100 ms allows 1. Might miss very short, focal abnormalities
Advantages Disadvantages
tomography for continuous acquisition of images of a 2. High radiation exposure
al technique moving object
1. Poor display of anatomic detail of the 3. Clinical applicability is limited (labour
ve tracheal and paratracheal structures
2. Correlates well with symptoms and intensive, requiring 160 images/patient)
画像所見
2. Unable to display simultaneouslybronchoscopic findings
the
anteroposterior and lateral walls of the airway
3.Cine magnetic
Operator dependent 1. Non-invasive high-resolution imaging with 1. Very limited clinical experience
umetric acquisition of data at both 1. Paired standard dose inspiratory-dynamic soft tissue contrast
resonance imaging excellent
ration and during dynamic expiration expiratory multislice helical CT potentially of ionizing radiation
2. Absence
trapping 3. Identification of vascular structures without
doubles radiation dose compared with Respirology (2006) 11, 388–406
display of anatomic detail of the airway single-phase acquisition iodinated contrast media
ent structures 4. Allows repeated assessments of the airway
深吸気時の胸部XPや胸部CTでは診断は困難.
ective interpretation and quantitative
ment of the degree of collapse
lumen during multiple respiratory maneuvers
ous display of the anteroposterior
teral walls of the trachea and allows
ction of three-dimensional images
well with bronchoscopy findings
nning time of only 50–100 ms allows
呼気, 吸気時の画像評価で気管支径の変化を追う方法,
1. Might miss very short, focal abnormalities
uous acquisition of images of a 2. High radiation exposure
bject
well with symptoms and Cine fluoroscopyによる評価, 気管支鏡による評価が有用
3. Clinical applicability is limited (labour
intensive, requiring 160 images/patient)
copic findings
sive high-resolution imaging with 1. Very limited clinical experience
soft tissue contrast
f ionizing radiation
tion of vascular structures without
吸気-呼気の気管左右径の変化値が
contrast media
peated assessments of the airway
ring multiple respiratory maneuvers 上気道で18%以上, 中気道で28%以上ならば,
TBMの可能性は89-100%, 上記(-)ではTBMは0-5%のみ.
Figure 2 Right antero-oblique
view fluoroscopic image during
inspiration (A) and expiration
(B) shows expiratory collapse
of the trachea (arrows) in a
patient with severe tracheobron-
chomalacia (TBM) due to post-
pneumonectomy syndrome.
Dynamic CT reveals normal tra-
cheal calibre during inspiration
(C) and collapse of the anterior
tracheal wall resulting in severe
crescent type TBM during expira-
tion (D) from the same patient.

12. 吸気, 呼気CTによる評価 Journal of Computer Assisted Tomography 2001;25(3):394–399
23名のControl, 10名のTBM(EDAC)患者で吸気, 呼気CTを評価
気管前後径(cm) 吸気時 呼気時 %変化
TBM Upper airway 1.6[0.9-2.5] 1.0[0.1-1.6] 39%[16-92]
Middle airway 1.9[0.6-2.4] 0.8[0.3-1.5] 53.5%[18-63]
Control Upper airway 2.0[1.3-2.4] 1.8[-9~14.2] 11.2%[-6~37]
Middle airway 1.9[1.4-2.3] 1.6[1.2-2.0] 12.7%[-19~33]
気管左右径(cm) 吸気時 呼気時 %変化
TBM Upper airway 2.6[1.7-4.7] 2.4[1.7-3.4] 3.9%[-5~15]
Middle airway 2.3[1.3-3.4] 1.1[0.9-2.5] 9.9%[-4~24]
TRACHEOMALACIA: DETECTION BY EXPIRATORY1.8[1.3-2.1]
Control Upper airway 1.9[1.6-2.4] CT 4.4%[-9~14] 397
Middle airway 1.9[1.4-2.3] 1.8[1.4-2.2] 4.4%[-26~28]

13. 気管断面積(cm2) 吸気時 呼気時 %変化
TBM Upper airway 4.3[1.7-9.2] 1.9[0.8-3.7] 50%[27-80]
Middle airway 3.3[1.4-5.2] 2.0[0.4-4.5] 44%[14-69]
Control Upper airway 2.7[1.9-3.9] 2.4[1.5-3.3] 12%[-1.5~33]
Middle airway 2.6[1.9-3.9] 2.2[1.5-3.3] 14%[4-33]
気管断面積の変化率で評価する場合,
上気道で>18%の変化はSn96%, Sp91%でTBMを示唆
大動脈弓レベルで>28%の変化はSn99%, Sp97%.
気管前後径の変化率で評価する場合,
上気道で>28%の変化はSn87%, Sp92%でTBMを示唆
大動脈弓レベルで>30%の変化はSn84%, Sp78%.
Journal of Computer Assisted Tomography 2001;25(3):394–399

14. CSA − minimum CSA)/maximum CSA) × 100%) was upright and lateral decubitus positions and during
significantly higher in patients with tracheomalacia spontaneous breathing as well as during various
Respirology (2006) 11, 388–406
気管支鏡所見
than in healthy volunteers during forced inspiration
and expiration and during coughing.
maneuvers such as cough, forced expiration, deep
inspiration. During these examinations changes in
bronchial and tracheal calibre can be measured,
extent of collapse is noted, narrowing can be classi-
Bronchoscopy fied as being of the crescent, saber-sheath type or cir-
cumferential type, cartilaginous weakening (TBM)
Bronchoscopy has been traditionally used to diag- can be differentiated from EDAC, and other abnor-
直視下で気管内の動きが観察できるため,
nose TBM and EDAC although these entities are rarely
described in terms of extent, severity, location and
malities may be discovered (Fig. 3).
The lack of a standard method to quantify the
associated anomalies. Although both rigid and flexi- severity of the airway collapse has made serial stud-
診断のGold Standardとなる. 狭窄の程度, タイプも分かる
ble bronchoscopy can be performed, flexible bron-
choscopy is preferable for diagnosis because the
ies, evaluation of therapies and comparisons between
patients difficult. In an effort to eliminate operator-
patient is able to breathe spontaneously and follow biased descriptions and to improve the accuracy of
TBM 吸気 EDAC 吸気 全周性TBM
TBM 呼気 EDAC 呼気 三日月型TBM

15. Fig. 1. Distal trachea (A), left main bronchus (B), and right main bronchus (C) before stent insertion. In this patient, excessive dynamic airway
Fig.collapse was caused by bulging bronchus (B), and right main bronchus (C) before stent mainstem bronchi (E) lumens completely restored
1. Distal trachea (A), left main of the posterior airway membrane. Lower trachea (D) and insertion. In this patient, excessive dynamic airway
collapsestent caused by bulging of the posterior airway membrane. Lower trachea (D) and mainstem bronchi (E) lumens completely restored
after was insertion. Respir Care 2007;52(6):752–754

16. Tracheobronchial stenting
8 K
h
a
b
w
TBMのFlow-vol curve f
Y
2
f
p
閉塞性障害を来すが, In
s
a
特異的とは言えない. 0
s
t
Thorax 1996;51:224-226 t
a
s
o
C
s
D
Flow-volume loop before (hatched line) and after (solid I
line) tracheal stenting. c
a

17. Respirology (2006) 11, 388–406
TBM and EDAC TBM, EDACの治療 399
Table 3 Proposed treatment modalities for tracheobronchomalacia and excessive dynamic airway collapse
Treatment Advantages Disadvantages
Medical management
1. Bronchodilators • Useful in mild cases of EDAC due to • May worsen airflow obstruction caused by
asthma and COPD TBM or EDAC alone
2. CPAP • Decreases pulmonary resistance • Intermittent treatment
• Improves airflow obstruction • Limited experience
• Decreases inspiratory work of breathing • May not suffice as a stand alone therapy for
severe cases
3. Disease specific drug • May suffice in less severe cases due to • Concomitant CPAP and/or stent placement
therapy asthma, COPD or RP often necessary
Minimally invasive surgery
1. Endolumenal airway stents • Improve symptoms and PFT • Limited data for isolated TBM or EDAC
• Maintain airway patency • Stent related complications
• Therapeutic trial before surgery • Often, multiple stents are required
2. Experimental approaches • Improvement in symptoms, • Preliminary results in a few patients
PFT and bronchoscopic aspects laser therapy
Open surgery
1. Tracheostomy • Stents the airways • Tracheomalacia and stenosis at the stoma
site
• If necessary, provides invasive ventilatory • May exacerbate TBM/EDAC
support
2. Airway splinting • Consolidates and reshapes the airway wall • Invasive, requires thoracotomy
• Offers long-term airway support • Complications common with Marlex mesh
3. Tracheal resection • May be curative for focal malacia • Experience limited to specialized centres
application and efficacy in humans
4. Experimental approaches • Less complications than other techniques • Remains unknown
in animal models
EDAC, excessive dynamic airway collapse; PFT, pulmonary function tests; RP, relapsing polychondritis; TBM,
tracheobronchomalacia.

18. thelium and normal cartilaginous growth.115 ever, suggest improvement in symptoms, ven
Respirology (2006) 11, 388–406
Diagnostic and management algorithm for tracheobronchomalacia (TBM) and excessive dynamic airway

19. Respirology (2006) 11, 388–406