Ultrasound Guided Pleural Procedures

Gamal Rabie Agmy ,MD ,FCCP Professor of Chest Diseases, Assiut University

OVERVIEW

• Evidence base for use of thoracic ultrasound– diagnostic and interventional

• Pleural effusion– Characteristics of effusions– Transudates vs exudates– Colour fluid sign– Formulas for volume estimation

• Pneumothorax

• Pleural thickening Identification, DD with pleural effusion

• Pleural tumours

WHY ULTRASOUND?• Not all opacification is fluid… 1

1 Psallidas et al. Clin Med 2014

WHY ULTRASOUND?

• Higher diagnostic sensitivity vs. plain chest radiography– pleural effusion +/- consolidation

• Accessible to clinician and patient– instant feedback to inform decision-making process

• Provides additional diagnostic information– echogenicity, septations, pleural thickening, underlying viscera

• Improves procedural outcomes– eliminates “dry tap”, limits risk of iatrogenic complications

THE EVIDENCE FOR FLUID

• Better than clinical examination 1

– 15% of clinically specified puncture sites inaccurate / “at risk”– 80% of these successfully aspirated / accessible with TUS– If clinical site not identified, TUS achieved in 54%– TUS prevented iatrogenic organ puncture in 10% of cases

• Reduces cost / complications in thoracentesis 2

– 61,261 thoracenteses, 47% performed without TUS– MV modelling and analysis– TUS reduced risk of pneumothorax by 19%– OR 0.81; 95% CI 0.74-0.90

1 Diacon et al. Chest 20032 Mercaldi et al. Chest 2013

INTERVENTIONS

• Thoracic ultrasound (TUS)– necessary for any pleural intervention for fluid– more sensitive than CXR for detection of fluid 1

– improves diagnostic accuracy and reduces complications 2

• BTS Pleural Disease Guidelines 3

1 Eibenberger KL et al. Radiology 19942 Diacon AH et al. Chest 2003

3 BTS Pleural Disease Guidelines. Thorax 2010

Normal lung surface

Left panel: Pleural line and A line (real-time). The pleural line is located 0.5 cm below the rib line in the adult. Its visible length between two ribs in the longitudinal scan is approximately 2 cm. The upper rib, pleural line, and lower rib (vertical arrows) outline a characteristic pattern called the bat sign.

http://radiographics.rsnajnls.org/cgi/content/full/22/1/e1/F3A

http://radiographics.rsnajnls.org/cgi/content/full/22/1/e1/F3C

SIZE OF EFFUSION ON US

Size / Volume measurement1: • 2cm depth of fluid = 480mls• 4cm depth of fluid = 960mls

Supine patients2:• Size calculation:

» Visceral – parietal (mm) x 20 = volume (mls)1

» Distance between posterior chest wall and lung of >50mm predicts >500ml thoracentesis vol2

1 = Balik, ICM 20062 = Roch, Chest 2005

Relative precision on estimating the fluid1 rib space small2-3 rib spaces moderate4>rib spaces large

Sonography Guided Interventions

1-Pleural effusion

Different Models of Cope Needle

Abrams Needle

Lung Biopsy Needles

Instruments for Ultrasound – guided Biopsy Forceps of the Pleura

• Compared to thoracoscopy the sensitivity of ultrasound guided forceps pleural biopsy in the diagnosis of malignant and tuberculous lesions was 85% and 88% respectively.

• The technique was absolutely specific in the diagnosis of malignant and tuberculous lesions.

Instruments for Ultrasound – guided Pleural Brushing

Procedure

   9 (41%) PFC9 (41%) PB

15 (68%) BFP16 (72%) PFC + BFP12 (55%) PB + PFC18 (82%) PB + BFP19 (86%) PB + PFC + BFP

Diagnostic  Yield

Different Models of Catheters for Pleural Drainage

2-Pneumothorax

the "seashore sign" (Fig.3).

Absent lung sliding

Exaggerated horizontal artifacts

Loss of comet-tail artifacts

Broadening of the pleural line to a band

Lung point

Loss of lung impulse

The key sonographic signs of Pneumothorax

3-Pleural thickening

4-Pleural tumors