Bronchial Thermoplasty Procedure

Equipment

“Alair” BT system delivers radiofrequency energy (electromagnetic energy) at approximately 65°C through the Alair RF controller/ energy generator and the Flexible Alair Catheter (Figs. 36.1 and 36.2) [2]. The Flexible Alair Catheter is a disposable single-use device with a basket-like expandable electrode array with a deployment handle that requires a grounding gel-­ pad attached to the patient to provide a complete circuit [11]. A fexible bronchoscope with a minimum 2.0 working channel is used.

BT is performed in three bronchoscopy treatment sessions at threeto six-week intervals, with separate systematic sessions for each lower lobe and the last session for combined upper lobes. The right middle lobe is typically not treated to prevent right middle lobe syndrome [1, 2]. Treatments are divided to minimize asthma exacerbation that can occur from post-procedural airway edema and infammation [11].

Pre-procedure

Patients should be in stable condition prior to BT procedure without a recent asthma exacerbation or pulmonary infection for at least 14 days before the procedure. Patients should be pre-treated with prednisone 50 mg daily for a total of 5 days—3 days before procedure, on the day of procedure, and on the day post-procedure—in addition to their baseline asthma therapy [2]. Additionally, patients undergo spirometry with measurement of FEV1 on the day of or day prior to the procedure, with goals of post-­bronchodilator FEV1 > 80% before the procedure.

Bronchoscopy

Bronchoscopy treatment sessions can be performed under moderate sedation or general anesthesia. The choice is based on local expertise and availability to achieve adequate sedation for the duration of the procedure, which lasts 40–60 min (approximately 44 min for each lower lobe and

Fig. 36.2  The Alair BT radiofrequency controller and catheter. (Courtesy of Boston Scienti c )

58 min for both upper lobes) [2]. Some of the frequently encountered symptoms during the BT procedure are cough, pain, and dyspnea.

Having an organized treatment plan is essential. Working from distal to proximal airways assures that all airways are treated and minimizes the chance of the same airway being treated twice [11]. First, airway inspection is performed with attention to any airway abnormalities. During

bronchoscopy, the Alair Flexible Catheter is introduced through the working channel of the fexible bronchoscope until four black catheter markings are visible with a catheter in position at the most distal subsegmental airways [11]. The deployment handle is used to open/expand the catheter electrode array until contact with the airway wall [2, 11]. Next, the “activations” are delivered by pressing and releasing the controller footswitch at ten-second intervals [1, 2, 11]. If the footswitch is released prematurely before completion of the treatment cycle, an error sound with the cancelation of treatment will be observed [11]. Additionally, if one of the four electrodes is not in contact with the airway wall, the cycle error will also sound with cessation of treatment [2]. After activation is delivered successfully, the catheter is closed and retracted to the following 5-mm black marking; subsequently, it is opened again with the next activation delivered [2]. The above steps are repeated for each black marking (total four) in each subsegmental airway of the

treatment lobe (Fig. 36.3). The BT activation map is used to document the number of activations­ per activation site (Fig. 36.4) [2]. Approximately 40–70 activations are delivered in the lower

lobes, and 50–100 in the upper lobes combined [2]. The typical sequence of treatment sessions is: right lower lobe at rst session, left lower lobe at second session, and the bilateral right upper