Intra Bronchial Valve

Intra Bronchial Valve

Jameela Almahmoudi

Definition

It is a minimally-invasive medical device designed  to treat severely diseased lung in patients with heterogeneous emphysema and evidence or markers of low collateral ventilation such as complete fissures, or damaged lung resulting in air leaks, by limiting airflow to selected areas.

History

References

Endobronchial occlusion with a plug or valve was one consideration, and research and development was started by multiple groups in the late 1990’s.

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At the 2002 World Congress for Bronchology, prototype designs and data from initial studies with swine were presented on valve placement and removal

• Eberhardt R, Gompelmann D, Schuhmann M, et al. Complete unilateral versus partial bilateral endoscopic lung volume reduction in patients with bilateral lung emphysema. Chest 2012; 142(4):900-908; doi: 10.1378/chest.11-2886
• Supplement to: Scuriba F, Ernst A, Herth FJF, et al. A Randomized Study of Endobronchial Valves for Advanced Emphysema. NEJM 2010; 363:1233-1244
• Hoffman E, Simon B and McLennan G. A structural and Functional Assessment of the Lung via Multi-detector-Row Computer Tomography. Proc Am Thorac Soc 2006; 3:519-534. DOI: 10.1513/pats.200603-086MS
• Heussel CP, Herth FJF, Kappes J, et al. Fully automatic quantitative assessment of emphysema in computed tomography: comparison with pulmonary function testing and normal values. Eur Radiol 2009; 19: 2391–2402; doi 10.1007/s00330-009-1437-z
• Springmeyer S, Bollinger C, Waddell T et al. Treatment of heterogenous emphysema using the Spiration IBV Valves. Thorac Surg Clin 2009; 19:247-253
• Thurnheer R, Engel H, Weder W, et al. Role of Lung Perfusion Scintigraphy in Relation to Chest Computed Tomography and Pulmonary Function in the Evaluation of Candidates for Lung Volume Reduction Surgery. Am J Respir Crit Care Med 1999;159(1):301-10

Animal studies continued, and by early 2003 over 2000 valves had been manufactured. Studies regarding lung volume reduction, valve removal, anchoring, and airway sizing were performed

The trial was continued in the United States to evaluate other treatment algorithms and testing methods and results after 75 subjects were presented at two forums in 2006. 520 valves were implanted at 9 US centers over a 27 month period between January 2004 and April 2006.

Outlines:

How it functions

Studies and research findings

The intra bronchial valve (IBV) is designed to

limit airflow to the portions of the lungs distal

to the valve, allowing mucus and air movement in

the proximal direction.

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• Definition
• History
• How IBV functions
• Procedure and equipment
• Target patients
• Advantages
• Studies and research findings
• References

The valves prevent further air trapping in the lung and enable the reduction of hyperinflation. The target is that the hyper-inflated sections gradually collapse, giving the rest of the lung more space to "breathe"

Procedure and equipment

Advantages

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4- Valve Placement

Multiple valvues are placed to occlude all the airways leading to the targeted lobe and enable atelectasis or significant lobar reduction.

1- Patient Selection & Treatment Approach

• Unilateral intrabronchial valve placement with complete occlusion appears superior to bilateral partial occlusion
• Target lobe will have severe, highly heterogenous emphysema with complete fissures.

2- Balloon Calibration

• Prior to the procedure, a sizing balloon is calibrated to enable precise measurement of the airways.

• Improve PFT results
• Minimal invasion to do the procedure
• Reduce hyperinflation
• More air entry in the healthy lobes
• Enable healthier tissue to expand
• Reduce SOB
• The diaphragm can return to its normal shape
• Improve health related QoL

3- Airway Sizing

• The calibrated balloon is used to determine the appropriate valve size for placement.

Target patients

Clinical evaluation:

• FEV1 less than 45% predicted
• Residual Volume (RV) > 150% predicted
• Total Lung Capacity (TLC) > 100% predicted
• 6MWD >= 150 m
• Hypercapnia with PaCO2 <= 50 mm Hg
• PaO2 > 45 mm Hg (6.0 kPa) on room air

Persistent air leaks continue to be a leading cause of increased hospitalization, morbidity and cost. Traditional management of persistent leaks involves chest drainage and observation followed by more invasive treatments when leaks do not resolve

A reduction in air flow to damaged lung has been shown to accelerate resolution of an air leak. Because air leaks are transient in nature, the IBV Valve was designed to be removed upon resolution of the leak

HRCT Analysis

1. Severe Emphysema

The lobe with the greatest amount of emphysema destruction should be evaluated first. If that lobe does not meet subsequent criteria, consider the second most diseased lobe.

• Quantitative Analysis Strategies:

Target lobe has >= 50% emphysema involvement, assessed quantitatively with HRCT at approximately –910 HU.

2. High Heterogeneity

A high heterogeneity difference between ipsilateral lobes is important to verify that the non-target lobes that will expand are healthier than the lobe targeted for treatment and volume reduction.

Quantitative Analysis Strategies:

Target lobe has >= 15 point heterogeneity difference with the healthier ipsilateral lobe, assessed quantitatively with HRCT.

Perfusion Scintigraphy may also be conducted to confirm heterogeneity and very low perfusion of the target lobe region.

3. Complete Fissures

The selected lobe must have an intact fissure separation with the ipsilateral lobe.

The IBV Valve has been demonstrated to enable significant lobar reduction in select patients.1,5 Lobar volume reduction is most pronounced and clinically beneficial in patients where the targeted lobe is isolated from collateral ventilation through complete fissures.

Quantitative Analysis Strategies:

Fissures may be visually estimated to be intact if it is>= 90% complete after viewing the HRCT in three dimensions (sagittal, axial, and coronal).