General description of procedure, equipment, technique

Flexible Fiberoptic Balloon Dilation

Initially defined in 1995 and subsequently described in European Respiratory Society (ERS) and American Thoracic Society (ATS) guidelines, interventional pulmonology is “the art and science of medicine as related to the performance of diagnostic and invasive therapeutic procedures that require additional training and expertise beyond that required in a standard pulmonary medicine training program.” Clinical entities encompassed within the discipline include complex airway management, benign and malignant central airway obstruction, pleural diseases, and pulmonary vascular procedures.

Diagnostic and therapeutic procedures pertaining to these areas include rigid bronchoscopy, transbronchial needle aspiration, autofluorescence bronchoscopy, endobronchial ultrasound, transthoracic needle aspiration and biopsy, laser bronchoscopy, endobronchial electrosurgery, argon-plasma coagulation, cryotherapy, airway stent insertion, balloon bronchoplasty and dilatation techniques, endobronchial radiation (brachytherapy), photodynamic therapy, percutaneous dilatational tracheotomy, transtracheal oxygen catheter insertion, medical thoracoscopy, and image-guided thoracic interventions. This presentation focuses on balloon bronchoplasty (balloon dilation).

The first report of successful use of a balloon to dilate a benign airway stricture described an eighteen-week infant with a post-surgical stricture. Initially, fluoroscopy or rigid bronchoscopy was used to guide the dilation procedure, but flexible fiberoptic bronchoscopy with balloon dilation was described in 1991. Since that time, relatively few reports, and only on small numbers of patients, have been published.


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Indications and patient selection

Balloon dilation is useful in the treatment of benign strictures complicating long-term endotracheal intubation, bronchial reimplantation, anastomosis of transplanted lungs, granulomatous disease (e.g., tuberculosis, Wegener’s granulomatosis), or smoke inhalation.

A suitable lesion for balloon dilation is one with web-like stenosis. The success using balloon dilation for lesions characterized by loss of supporting structures is poor. In these cases, medical treatment of the underlying cause of the stricture should be performed prior to attempts at dilation. For example, local treatment of strictures secondary to tuberculosis should not be attempted until adequate antimicrobial treatment is given.

Contraindications

There are no procedure-specific contraindications except for those of flexible bronchoscopy such as refractory hypoxia, coagulopathy, acute myocardial infarction, etc.

Details of how the procedure is performed

Bronchoscopic balloon dilation is a relatively simple technique. A flexible fiberoptic bronchoscope is used in the standard manner, with administration of topical anesthesia and moderate sedation. After identification of the stenosis, the bronchoscopist can make small radial incisions at 12, 3 and 9 o’clock to better control dilation and mitigate risk of airway fracture. This is most commonly achieved using an electrocautery knife. Next, a 0.89mm-diameter guidewire is passed through the working channel of the bronchoscope and advanced beyond the stenosis, its passage monitored fluoroscopically. Once the guide wire is in place, the bronchoscope is removed and the guide wire is left in place.

Next, a balloon catheter that has been selected based upon the diameter of the stenosis is passed. The balloons’ diameters are variable, so dilation may be initiated with a small size and the size advanced as necessary. Radio-opaque markings on the balloon allow positioning of the balloon across the stenosis. If the balloon does not extend enough distally, it tends to slip out of the stenosis upon inflation. If the balloon is ineffective in achieving dilation, it is replaced a larger one. Repeated inflations may be performed using the same balloon. The balloon is inflated with saline rather than air as there is greater reliability of the pressure applied. The number of atmospheres of pressure applied to the airway is directly related to the size of the balloon.

Another commonly employed technique is to perform the dilation by passing the balloon through the working channel with the cap removed. The bronchoscope is seated just proximal to the stenosis and the balloon advanced into the stenosis. Care must be taken to center the balloon in the stenosis. Again, serial inflations may be required. Generally, the duration of each inflation is between 30 and 60 seconds to avoid prolonged periods of inadequate distal ventilation, particularly with more central lesions. A similar technique may be performed through the rigid bronchoscope.

Interpretation of results

Success or failure of the procedure is immediately visible to the bronchoscopist as enlargement of the airway.

Performance characteristics of the procedure (applies only to diagnostic procedures)

Not applicable.

Outcomes (applies only to therapeutic procedures)

Several case series of fiberoptic bronchoscopic balloon dilation in adults have been reported. In the largest series, which involved nineteen stenoses in sixteen patients, initial success was achieved in thirteen of nineteen interventions; six dilations were unsuccessful because stenoses were caused by localized bronchomalacia. In general, an average success rate of approximately 50 percent has been reported with reinterventions.

Surgical treatment of the stenotic segments is technically feasible in most patients.

Endobronchial cryotherapy in conjunction with balloon dilation has been used in two cases of benign airway stenosis with success. However, an airway stent is usually needed to support the airway if there is damage to cartilage in the trachea or bronchi, resulting in bronchomalacia.

Balloon dilation is a minimally invasive, safe, rapid procedure. However, multiple dilations may need to be performed in order to maintain a satisfactory result, and only web-like stenosis can be reliably improved with balloon dilation alone. If the cartilage has been compromised, a stent is needed to support the airway.

Alternative and/or additional procedures to consider

Topical mitomycin C.

Complications and their management

Excessive balloon inflation or a large length has the potential to lacerate or rupture the airway, but these complications have not been reported.