ROUTINE BRONCHOSCOPIC SAMPLING TECHNIQUES -part 2.pptx

bronchoscopic sampling

1. ROUTINE BRONCHOSCOPIC SAMPLING TECHNIQUES C TBNA AND LINEAR EBUS Dr Dimple Makhija Senior Resident SGPGI

2. INTRODUCTION

3. DEFINITION “Father of TBNA”- Schieppati TBNA is a technique for performing cytological, histological, or microbiological sampling of lesions ✔ from airway ✔ lung parenchyma ✔ mediastinal structures adjacent to tracheobronchial tree

4. TBNA – Different Methods Conventional TBNA CT guided TBNA Electromagnetic Navigation guided TBNA Ultrasound guided TBNA 1) Radial Probe guided 2) Convex Probe guided (real time)

5. First developed in 1949 for use with the rigid bronchoscope Wang et al. designed a prototype needle for flexible bronchoscope in 1978 EBUS was first introduced in 1992 when endovascular probes were introduced through bronchoscopes Radial probe EBUS introduced in 1990’s Convex/Linear probe EBUS introduced in 2005

6. CONVENTIONAL TBNA

7. Technical consideration Six essential "T's" of transbronchial needle aspiration Tomographic evaluation Type of Needle Technique Tissue preparation Tissue interpretation Trained assistant

8. TECHNICAL CONSIDERATIONS CHEST CT E valuate the relationship of the tracheobronchial tree to the surrounding structures (lymph nodes and blood vessels)  M aximizes diagnostic yield and safety Location of the lymph node - majority of lymph node stations can be reached 2R, 2L, 4R, 4L, 7, 10R, 10L, 11R, and 11L B est visualized by imagining the interior of the airway as a clock face, using the carina as the central reference point .

9. ANATOMIC CONSIDERATIONS STATION LEVEL BEST APPROACH 7 SUBCARINAL From a point 3-5 mm below on either side of the primary carina, with the needle pointed in an inferomedial direction.

10. Normal Anatomic Relationships At The Level Of The Main Carina

11. STATION LEVEL BEST APPROACH 4R RIGHT PARATRACHEAL From the second or third intercartilaginous space (or 2 cm) proximal to the carina at 1-2 o'clock position.

12. Normal Anatomic Relationships At The Level Of The Distal Trachea

13. STATION LEVEL BEST APPROACH 4L LEFT PARATRACHEAL From the lateral wall of the left main bronchus at the level of the carina at the 9 o'clock position.

14. c‑TBNA is more commonly described for aspiration of lymph nodes at station 4R,4L, 7, 10 , 11 A systematic review of 53 studies and 8000 patients reported that sampling from station 4R provided the highest diagnostic yield (70%), followed by station 7 (69%), 10/11 (67%), and 4L (60%) Respiration 2013;86:123‑34

15. Size of the lesion and lymph nodes – for good diagnostic yield Lymph node size >2 cm in short axis diameter - strong predictor of higher diagnostic yield during c‑TBNA For lymph nodes between 1 - 2 cm size, yield of c‑TBNA =13.3% - 87% significantly lower yield, if lymph nodes are <1 cm c‑TBNA should be considered in patients with lymph node size of ≥1 cm in short axis at 4R or 7 locations and size of ≥2 cm at hilar or interlobar nodal locations (10/11) (Indian guidelines) For smaller size LN- EBUS TBNA preferred

16. Type of Needle Needle systems consist of A retractable sharp beveled flexible needle A flexible catheter A proximal control device to manipulate the needle, the stylet, or both, and a side port through which suction can be applied

17. Ideally retractable needles should be used 20-22g needle for cytology specimen/tissue culture 19g needle – core tissue ( to evaluate tissue architecture) C atheter should be flexible enough to maneuver into peripheral locations Use of histology needle (19G or 18G) provides higher diagnostic yield without increasing the rate of complications compared to cytology needle (21G or 22 G) in patients with unselected mediastinal lymphadenopathy or suspected malignancy

18. Technique- 10 steps to conventional TBNA 1.Insert the needle catheter through the working channel of the bronchoscope keep the bevel of the needle protected inside the metal hub keep the scope as straight as possible 2.Extend the catheter out of the working channel with the scope in a neutral forward viewing position, in the central airways

19. 3. The needle is extended, locked in place, and anchored at the target site 4. Using either the jabbing, the piggy-bag, the hub-against-the-wall, or the cough method, push the needle through the trachea-bronchial wall to its fullest extent

20. Angle of transbronchial puncture- The TBNA needle should make an angle >45º with the airway wall.

21. T echniques for transbronchial penetration JABBING METHOD At the area of interest- catheter is advanced out of the end of the bronchoscope such that the hub is visible. The needle is then advanced out of the catheter and the bevel of the needle is positioned against the airway wall. The bronchoscope is stabilized and the both catheter and needle are advanced such that the needle penetrates the airway wall. Scope fixed at nose or mouth by the assistant

22. Hub against the airway method The catheter is advanced out of the end of the bronchoscope such that the hub is visible. (A) The catheter is positioned against the airway wall. (B) The bronchoscope is stabilized and the needle is advanced such that the needle penetrates the airway wall.

23. Piggy Back method The catheter is advanced out of the end of the bronchoscope such that the hub is visible The needle is then advanced out of the catheter and the bevel of the needle is positioned against the airway wall (B) The bronchoscope, catheter and needle are advanced en bloc such that the needle penetrates the airway wall

24. Cough Method The catheter is advanced out of the end of the bronchoscope such that the hub is visible The needle is then advanced out of the catheter and the bevel of the needle is positioned against the airway wall (B) The patient is then asked to cough as the needle is advanced by jabbing or piggy back method and needle penetrates the airway wall

25. 5. Apply suction at the proximal end of the needle using a 20- to 50-cc syringe 6. Cytology specimen is obtained by agitating the catheter at its proximal end while applying the suction. Histology specimen is obtained by moving the needle to and fro by 3 to 4 mm while applying the suction 7. Release the suction 8. Remove the needle from the tracheobronchial wall 9. Pull the needle back into the catheter 10. Remove the catheter from the working channel of the scope in a single smooth motion and collect the specimen

26. Number of Passes 3–4 aspirates per node for optimum yield during c‑TBNA Additional aspirations should be obtained if required for other necessary investigations Role of vacuum suction Applied after the needle is completely inserted into the target site Can be applied manually using a simple syringe or using a modified technique by adding a plunger lock to the syringe (auto‑aspiration)

27. Factors influencing diagnostic yield of TBNA Likelihood of malignancy Location (airway lesion, subcarinal and right paratracheal lymph node), size (bulky), and appearance ( eg , spiculated masses) of the lesion or lymph node Visibility and carinal involvement of the tumor , as determined by bronchoscopy Image guidance Operator/team experience Cytopathology experience with small biopsy specimens

28. Complicatons Damage to the working channel of bronchoscope Fever Transient bacteremia Oozing of blood Inadvertent puncture of mediastinal structures Pneumothorax/pneumomediastinum

29. ENDOBRONCHIAL ULTRASOUND

30. CONVEX PROBE EBUS RADIAL EBUS

31. Radial Probe EBUS Convex probe EBUS Transducer Rotating mechanical transducer Fixed array of electronic transducer aligned in a curvilinear pattern View 360 degree to long axis of scope Angle of view - 80 degree Direction of view - 35 degree forward oblique Frequency 20 MHz 5-12 MHz Tissue penetration 4-5 cm 5 cm Image quality Airway layers identified Airway layers cannot be identified Real time TBNA Not possible Possible Doppler Not possible Possible

32. EBUS needle parts

33. Types of EBUS needle Dedicated 22 G needle Newer needles 19 G Olympus flex needle (better flexibility, better cores) Cook 22 G and 25 G needle Boston Acquire 22 G and 25 G needle

34. Boston Acquire TBNA needle Three point provide stability at puncture site Maximise tissue capture and minimize fragmentation

35. Choosing the patient I ndications of EBUS Mediastinal and hilar lymph node staging of lung cancer Mediastinal restaging of lung cancer Diagnosis of lung tumors adjacent to large airwrays Diagnosis of mediastinal tumor , sarcoidosis, lymphoma

36. Insertion to Visualization of Lymph Node Optical system of the CP-EBUS provides an 80 field of view at a 35 forward oblique angle To obtain a straight view, the bronchoscope needs to be slightly flexed down Endobronchial images obtained by the CP-EBUS are not as clear as the conventional flexible bronchoscope image

37. Preferrable to examine the tracheobronchial tree using the conventional video bronchoscope prior to EBUS-TBNA After local anesthesia and conscious sedation, the CP-EBUS is inserted orally into the trachea It should be passed through the vocal cords by visualizing the anterior angle of glottis Do not force the scope into the glottis, since the tip is not visible and may cause dislocation of the cartilage

38. Anterior angle of glottis Tip gently pressed onto the airway

39. EBUS scope is introduced into the airway until the desired position is reached for imaging Balloon is inflated with normal saline to provide maximum contact with tissue of interest Tip of the CP-EBUS is flexed and gently pressed onto the airway Lesion of interest is localized and tip is carefully adjusted to visualize maximum diameter of the lymph node in the center of the ultrasound image.

40. Mapping of Mediastinal lymph nodes Doppler mode is used to identify surrounding vessels and the blood flow within lymph nodes Assess nodal characteristics- Size Margins Heterogenous/homogenous opacity Vascularity of the node Presence of central hilar structure(CHS)/coagulation necrosis sign(CNS)/ central intranodal vessel (CIV)

41. Features of benign nodes Oval shape <1 cm Indistinct margin Presence of a central hilar structure Relatively high echogenicity Homogenous echogenicity

42. Features of malignant nodes Round shape size >1 cm Distinct margin Absence of the central hilum Eccentric cortical thickening, Relatively low echogenicity, heterogenous echogenicity, Presence of necrosis

43. HOMOGENOUS NODE HETEROGENOUS NODE

44. Coagulation necrosis sign

45. Systematic assessment of Lymph nodes Lymph node assessment is started from the hilum (the side of the primary lung cancer), working up into the mediastinum and ending in the contralateral hilum To avoid contamination and upstaging, EBUS-TBNA should be performed from the N3 nodes, followed by N2 nodes and N1 nodes

46. Station 4R Keep the bronchoscope in trachea looking straight towards the main carina Turn to the two o’clock position and press the tip just proximal to the main carina Look for the SVC and the azygos vein branching from the SVC. Station 4R is close to the SVC and the azygos vein

47. 4R

48. Station 4L Facing the main carina, turn the bronchoscope to the 10 o’clock position and press the tip just proximal to the main carina and scan the area for station 4L. The aortic arch can be followed to the aorto-pulmonary window. The aortic arch is proximal and the left main pulmonary artery is distal

49. Aorta PA 4L

50. Station 7 Visualized from either the right or the left main bronchus. On the right side, turn to the 12 o’clock position and press the tip against the right main bronchus where the main stem of the pulmonary artery is visualized. After confirmation with the Doppler mode, turn the tip to the 9 o’clock position to visualize station 7.

51. Steps of EBUS 1. Advance EBUS needle through WC with scope in neutral position 2. Secure needle assembly by sliding the flange, locking it in place

52. 3. Release the sheath screw 4. Advance and lock the sheath when it is visualized in monitor

53. 5. Locate the target lymph node to be sampled using US imaging 6. Release the needle guard

54. 7. Advance the needle using the quick “jab” method

55. 8. Visualize needle entering target node with US 9.Move the stylet in and out a few times to dislodge debris within the needle 10. Withdraw the stylet

56. 11. Attach suction syringe to the needle 12. Apply suction

57. 13. Move the needle back and forth within the node 10 times 14. Release suction 15. Retract the needle into the sheath 16. Secure the needle guard 17. Unlock the needle assembly 18. Remove the needle and sheath; collect the specimen

58. Sample Handling and ROSE B y using air from an empty syringe the specimen is sprayed onto the slide smearing it using another slide, and immediately placing it in a 95 percent alcohol solution Also, one of the slides can be prepared for rapid onsite cytologic evaluation (ROSE) Histological cores are fixed with formalin

59. ROSE of the specimen by a cytopathologist for sample adequacy has been demonstrated to increase diagnostic yield Chest. 2013;143(4):1036 Chest. 2014;145(1):60 Aspiration is repeated if ROSE is non diagnostic or quantity of cellular material is insufficient for anciliary testing ROSE helps in reducing the number of needle passes avoiding additional sampling techniques decreasing complication rate, time and costs.

60. Complications Bleeding from major vessels Pneumomediastinum, Mediastinitis, Peumothorax , Bronchospasm Laryngospasm.

61. Advantages and Disadvantages Advantages Disadvantages Real time guidance Needle targeted in specific areas within node (heterogenous part, avascular regions) High sensitivity Safety Larger size (limited access to distal airways) Oblique view (poor airway visualization) White light image below par ( airway inspection required through conventional bronchoscope) Cost Training

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