Dynamic Central Airway Obstruction: Tracheomalacia, Tracheobronchomalacia, And Excessive Dynamic Airway Collapse: Classification, Diagnosis, and Treatment

1. Dynamic Central Airway Obstruction: Tracheomalacia,Tracheobronchomalacia, And Excessive Dynamic Airway Collapse Classification, Diagnosis, and Treatment Bassel Ericsoussi, MD Pulmonary and Critical Care Fellow University of Illinois Medical Center at Chicago

2. DEFINITION Dynamic Central Airway Obstruction Luminal narrowing > 50% during expiration (Diffuse or segmental ) Intrathoracic, obstruction, airway collapse typically occurs during expiration Tracheomalacia (TM) - Tracheobronchomalacia (TBM) Cartilageweakness In the trachea (TM) Extending into one or both mainstem bronchi (TBM) Excessive Dynamic Airway Collapse (EDAC) Bulging of the posterior membrane into the airway lumen during exhalation Tracheomalacia and tracheobronchomalacia in children and adults: an in-depth review. Chest. 2005;127(3):984-1005

3. Bronchoscopic view A: Normal lumen during inhalation B: Near total collapse during quiet exhalation Tracheomalacia and tracheobronchomalacia in children and adults: an in-depth review. Chest. 2005;127(3):984-1005

4. CT scan airway reconstruction of the trachea A: the trachea during inhalation B: segmental tracheal collapse during exhalation Tracheomalacia and tracheobronchomalacia in children and adults: an in-depth review. Chest. 2005;127(3):984-1005

5. CLASSIFICATIONThe Shape of the Trachea Crescent TM Scabbard Shape Anteroposterior Tracheal Narrowing Saber-sheath TM Fissure Shape Lateral Tracheal Narrowing

6. Diffuse TM Excessive collapse of a long segment of the intrathoracic trachea during expiration Segmental TM Segmental tracheal collapse during exhalation CLASSIFICATIONDistribution

8. Congenital TM Less common Inherited Presents during childhood Idiopathic Giant Trachea (IGT) Typically presents during adulthood Atrophy of the longitudinal elastic fibers and thinning of the muscularis mucosa Tracheobronchomegaly. Chest. 1994;106(5):1589-90.

9. Idiopathic Giant Trachea (IGT)

10. Tracheobronchomegaly (TBM)(Mounier-Kuhn Syndrome) The diameter of the trachea > 3.0 cm Right mainstem bronchus > 2.3 cm Left mainstem bronchus > 2.3 cm Usually the peripheral airways maintain a normal diameter Chronic accumulation of secretions Recurrent infections Tracheal diverticuli Bronchiectasis Pulmonary fibrosis Tracheobronchomegaly--the Mounier-Kuhn syndrome. Br J Radiol. 1984;57(679):640-4.

11. Acquired TM Tracheostomy or Endotracheal Intubation Risk factors Recurrent intubation Prolonged intubation Concurrent high-dose steroid therapy Destruction of the tracheal cartilage at the stoma or the inflatedcuff site Pressure necrosis Impaired blood flow Recurrent infections Mucosal friction and inflammation Acquired tracheomalacia: etiology and differential diagnosis. Chest. 1975;68(3):340-5.

12. Benign mediastinal goiter Malignancy Vascular compression Abscess Cyst Acquired TMChronic Compression of the Trachea Respiratory complications after thyroidectomy and the need for tracheostomy in patients with a large goitre Br J Surg. 1999;86(1):88-90

13. TM due to vascular compression Double aortic arch Vascular ring encircling the trachea and esophagus Tracheal narrowing caused by the vascular ring Double Aortic Arch Cardiothoracic Surgery Network. 29-Sep-2009

14. Retrospective chart review and data analysis January 2004 through February 2008 145 pts with RP Nearly 50% some degree of TM (focal or diffuse) 26% subglottic stenosis The rest focal stenosis in different areas of the bronchial tree 40%underwent intervention Balloon dilatation Stent placement Tracheotomy The majority of patients experienced improvement in airway symptoms after intervention Acquired TMRelapsing Polychondritis (RP) Relapsing polychondritis and airway involvement. Chest. 2009;135(4):1024-30

15. Moderate tracheal obstruction from diffuse wall thickening with sparing of the posterior wall Anterior bronchial wall thickening with posterior wall sparing Relapsing polychondritis and airway involvement. Chest. 2009;135(4):1024-30 Sparing of the Posterior Wall in RP

16. Chronic bronchitis Cystic fibrosis (CF) Observational study 40 adults with CF and 10 control subjects Dynamic CT showed TM 24/40 (69%) pts with CF None of the controls Acquired TMRecurrent Infection Tracheomalacia in adults with cystic fibrosis: determination of prevalence and severity with dynamic cine CT. Radiology. 2009;252(2):577-86.

17. Chronic inflammation due to the inhalation of irritants (cigarette smoking) 214 pts with chronic bronchitis 50/214 pts with TBM 2150 pts with TBM 53% concurrent chronic bronchitis Acquired TMSevere Emphysema Chronic bronchitis. A bronchologic evaluation. ORL J OtorhinolaryngolRelat Spec. 1976;38(3):178-86 Acquired tracheobronchomalacia.Ann Clin Res. 1977;9(2):52-7.

18. Retrospective study 116 infants (between the ages of 3 and 28 months) with chronic respiratory problems 54/116 laryngomalacia and tracheomalacia 70% had GERD documented by reflux studies 62/116 control group 39% had GERD GERD is prevalent among infants with large airways malacia Acquired TMGERD The prevalence of gastroesophageal reflux in children with tracheomalacia and laryngomalacia. Chest. 2001;119(2):409-13

19. EPIDEMIOLOGY Acquired TM more common in men > 40 yo (Older studies) 4283 pts with pulmonary disease underwent bronchoscopy 542 pts (12.7%): TM (the airway caliber narrowed > 50%) > 70%: age 50-80 Diagnosis, incidence, clinicopathology and surgical treatment of acquired tracheobronchomalacia. Nihon Kyobu Shikkan Gakkai Zasshi. 1992;30(6):1028-35

22. CLINICAL MANIFESTATIONS Asymptomatic in mild cases The severity of airway narrowing progresses in certain clinical situations Infection General anesthesia Progressive hypercapnic respiratory failure Liberation from mechanical ventilation A case of tracheomalacia during isoflurane anesthesia. AnesthAnalg. 1995;80(5):1051-3. Respiratory failure due to tracheobronchomalacia. Thorax. 1996;51(2):224-6.

23. CLINICAL MANIFESTATIONS Dyspnea, cough, and sputum retention (most common) Expiratory wheezing or stridor Paroxysmal cough Recurrent infection Episodic choking, syncope a/w forced exhalation and cough Maneuvers can sometimes elicit symptoms Forced exhalation Cough Valsalva maneuver Supine position Acquired tracheobronchomalacia. Eur J Respir Dis. 1982;63(5):380-7.

24. DIAGNOSISFlexibleBronchoscopy The diagnostic gold standard The severity of the dynamic central airway collapse: Mild: 50% obstruction Moderate: 75% obstruction Severe: the anterior and posterior walls touch Acquired tracheobronchomalacia. A clinical study with bronchological correlations. Ann Clin Res. 1977;9(6):350-5.

25. DIAGNOSISComputed Tomography In some cases the collapse can not be demonstrated on end- expiration (false negative) The collapse is much more prominent on dynamic imaging Acquired tracheomalacia: detection by expiratory CT scan. J Comput Assist Tomogr. 2001;25(3):394-9.

26. Dynamic Expiratory CT vs. Bronchoscopy Retrospective study (19 mon period) Beth Israel Deaconess Medical Center 29 pts with airway malacia identified with bronchoscopy End-expiratory and dynamic expiratory CT performed within 1 week of bronchoscopy CT correctly diagnosed malacia in 28 of 29 patients 97% accuracy CT is able to show the distal extent of the disease into segmental and subsegmental bronchi Implications on treatment: neither stenting nor surgery can correct the distal disease Comparison of Dynamic Expiratory CT With Bronchoscopy for Diagnosing Airway Malacia: A Pilot Evaluation. Chest. 2007;131(3):758-64.

27. Criteria for Diagnosing TM by CT Same as those for diagnosing TM by bronchoscopy Mild: 50% obstruction Moderate: 75% obstruction Severe: the anterior and posterior walls touch

28. WHAT IS THE OPTIMAL DIAGNOSTIC THRESHOLD FOR LUMINAL NARROWING? Currently: (>50% expiratory reduction in cross-sectional area) This is may be not true Prospective study on 51 healthy volunteers Dynamic expiratory CT (forced exhalation CT) 78% (40/51) pts exceeded the current diagnostic criterion for tracheomalacia (P<.001) Tracheal collapsibility in healthy volunteers during forced expiration: assessment with multidetector CT. Radiology. 2009;252(1):255-62.

29. Supportive but not diagnostic The obstruction on the spirometry usually is proportional to the severity of the airway collapse Rapid decline in the maximal expiratory flow after a sharp peak (collapse of central airways due to negative transmural pressure) DIAGNOSISPulmonary Function Tests Acquired tracheobronchomalacia. A clinical study with bronchologicalcorrelations. Ann Clin Res. 1977;9(6):350-5

30. Flow Oscillations on the Flow-volume Loop Sequence of alternating decelerations and accelerations of the expiratory flow ("saw-tooth" pattern) Large retrospective survey 2,800 flow-volume loops 1.4% (40/2800) flow oscillations Can be due Tracheobronchomalacia OSA Structural or functional disorders of the larynx Neuromuscular diseases Flow oscillations on the flow-volume loop: a nonspecific indicator of upper airway dysfunction. Bull EurPhysiopatholRespir. 1985;21(6):559-67 Tracheobronchomalacia: A Cause of Flow Oscillations on the Flow-Volume Loop. Chest 2000;118;1519

31. Pt with Parkinson's Disease and UAO Flow-volume loop at baseline Flow oscillations due to UAO Levodopa improved of the saw-tooth pattern Effects of Levodopa on Pulmonary Function in Parkinson’s Disease. CHEST February 2001 vol. 119 no. 2 387-393

32. TREATMENT Asymptomatic: no treatment Symptomatic:treat the underlying cause TM associated with tracheal stenosis due to prolonged intubation : surgical repair (resection and reconstruction) TM due to COPD: optimize COPD therapy Persistent symptoms following optimization of the coexisting condition Baseline functional status (PFT, 6MWT, QOL) Stenting trial (Silicone) Grade 2C Grade 2C recommendation very weak recommendation; other alternatives may be equally reasonable Tracheomalacia and tracheobronchomalacia in children and adults: An in-depth review. Chest 2005; 127:984.

33. TREATMENTIdentifying Patients Who are Most Likely to Benefit from Central Airway Stabilization Stenting trial (Silicone) Symptoms/functional status unchanged or worse Remove stent Grade 2C No further intervention Positive pressure therapy or T-tube may be beneficial Symptoms improved Surgical candidate: surgery Grade 2C Not surgical candidate: long term stenting Grade 2C Tracheomalacia and tracheobronchomalacia in children and adults: An in-depth review. Chest 2005; 127:984.

34. STENTING Silicone stents are preferred Insertion requires rigid bronchoscopy and general anesthesia Easily repositioned and removed Airway stabilization with silicone stents for treating adult tracheobronchomalacia: a prospective observational study. Chest. 2007;132(2):609-16.

36. Tracheal and Bronchial silicone stents For tracheal and bronchial obstructions and stenosis Non-adherent smooth surface Anti-migration stud system Available in clear or radiopaque material Tracheobronchial Y Stent Less likely to migrate Non-adherent smooth surface Anti-migration stud system Available in clear or radiopaque material

37. Complications of Silicone Stents Silicone stents often migrate (manifests as a new cough) Requires repositioning, removal, or replacement of the stent Silicone Y-shaped stents are less likely to migrate than tubular silicon stents Infection, cough, mucus-plugging, and granulation tissue Complications of silicone stent insertion in patients with expiratory central airway collapse. Ann Thorac Surg. 2007;84(6):1870-7.

38. Retrospective chart review 15 pts who failed medical therapy and were not surgical candidates, treated by silicone stent insertion Short term complications (within 48 hrs) 3/15 stent-related complication 12 pts underwent 188 days follow-up 10/12 stent related complications Granulation, migration, and mucus plugging Short and Long Term Complications of Silicone Stents Complications of silicone stent insertion in patients with expiratory central airway collapse. Ann Thorac Surg. 2007;84(6):1870-7.

39. Metal Stents (Expandable Wire Stents) Not recommended in benign airway obstruction (TM) More useful in malignant airway obstruction Easy placement with flexible bronchoscopy May preserve the mucociliary function (some stent types) Cannot be easily removed a/w with many complications Granulation tissue Breakage Airway obstruction Airway perforation Use of expandable wire stents for malignant airway obstruction. Ann Thorac Surg. 1994;57(6):1573-7; discussion 1577-8.

40. Fractured metallic stent Torn silicone stent

41. SURGICAL REPAIR Tracheobronchoplasty The definitive operative technique All surgically candidate pts with symptomatic improvement on stent trial should undergo tracheobronchoplasty Splinting of the posterior wall of the trachea and main stem bronchus with polypropylene mesh Tracheobronchoplasty for severe tracheobronchomalacia: a prospective outcome analysis. Chest. 2008;134(4):801-7.

42. Dynamic Bronchoscopy Forced Expiratory Maneuver Dynamic CT Forced Expiratory Maneuver 3 months Post-op Tracheobronchoplasty for severe tracheobronchomalacia: a prospective outcome analysis. Chest. 2008;134(4):801-7.

43. Prospective cohort study 35 pts with severe symptomatic tracheomalacia underwent tracheobronchoplasty using a polypropylene mesh 3 months follow-up: improvement QOL Dyspnea Mean exercise capacity Functional status SURGICAL REPAIR Tracheobronchoplasty Tracheobronchoplasty for severe tracheobronchomalacia: a prospective outcome analysis. Chest. 2008;134(4):801-7.

44. SURGICAL REPAIROther Possible Surgeries Conventional resection and reconstruction Localized, segmental cervical tracheomalacia Tracheal stenosis is a potential complication Tracheal replacement Tracheal replacement with cryopreservedallogenicaorta. Chest. 2010;137(1):60-7. Tracheal replacement with aortic allografts. N Engl J Med. 2006;355(18):1938-40. Tracheal replacement: a critical review. Ann Thorac Surg. 2002;73(6):1995-2004.

45. Tracheostomy Tracheostomy tube should bypass the abnormal tracheal segment May require longer tracheostomy tubes In diffuse TM , tracheostomy may be beneficial as a route to deliver positive airway pressure Tracheostomy itself can worsen TM by destroying the tracheal cartilage and weakening the tracheal wall Tracheostomy is a treatment of last resort.

46. Tracheostomy and Tracheal T-Tube Functions like a straight stent, spanning the cervical trachea Sometimes used for long-term stenting Localized, segmental cervical tracheomalacia Use of a T-tube stent to treat a patient with tracheal stenosis. JAPPA.

47. Positive Pressure Ventilation Indicated in diffuse dynamic airway obstruction Indicated in pts failed stenting trial Symptoms unchanged or worse with stenting Pt initially receives continuous CPAP Gradual transition to intermittent CPAP Improvement Sputum production Atelectasis Exercise tolerance Symptoms Reduced need for medical care BIPAP may be used in dynamic central airway obstruction with hypercapnic respiratory failure Treatment of diffuse tracheomalacia secondary to relapsing polychondritis with continuous positive airway pressure. Chest. 1997;112(6):1701-4. Nasal continuous positive airway pressure in the treatment of tracheobronchomalacia. Am Rev Respir Dis. 1993;147(2):457-61.

48. Treatment Algorithm For Adult Tracheomalacia Tracheomalacia and tracheobronchomalacia in children and adults: An in-depth review. Chest 2005; 127:984.