Fig. 38.2  Navigational bronchoscopy techniques. Screen views of LungPoint (Bronchus Technology, Redmond, WA, USA) Navigational Bronchoscopy software. (a) Screenshot of view from main carina, with subsequent axial planning image highlighting aorta in red and three-­

dimensional image of airway tree and major vessels. (b) Virtual image of left upper lobe entrance with corresponding axial images and three-dimensional airway images. The software pre-labels major airways with segmental anatomy identi ed from computed tomography scans

Fig. 38.3  Cryoprobe via fexible bronchoscopy for use during foreign body removal. A 13-year-old girl developed respiratory failure from viral pneumonia and was placed on extracorporeal membrane oxygenation (ECMO). During this course she developed recurrent hemoptysis, eventually

leading to airway obstruction (a). The use of the fexible cryoprobe in multiple freeze/thaw cycles (b) enabled to remove large amounts of blood clot casts that had been occluding the central airways (c)

Therapeutic Procedures

Multiple publications are currently available regarding the use of rigid bronchoscopy within pediatrics, with many authors’ training originating in otolaryngology, thoracic surgery, and/ or pediatric surgery. Within this review we have elected to exclude foreign body retrieval, as this remains the most commonly reported use of rigid bronchoscopy in children and many other reviews are currently available for such purposes [37–39]. We instead elected to focus on other less described therapeutic bronchoscopic interventions in pediatrics.

Within the pediatric population, central airway obstruction (CAO) related to non-malignant causes remains more common than malignant disease. This distinction remains quite important and is the central challenge in long-term management of pediatric CAO. Another challenging factor is the future ability of airway size changes as the child ages, providing predictable increase in airway dimension. This fact can provide both advantages (improvement in airway stenosis and malacia as the obstruction may represent a smaller fraction of the overall airway diameter) and disadvantages (growth can result in in situ stent migration from airway diameter changes). While surgical treatment

remains the optimal therapy for airway obstruction in non-malignant disease, airway stenting and other endoscopic interventions may provide a viable solution for non-surgical candidates or as a bridge to surgery. Endobronchial airway stenting for malacia warrants ongoing multidisciplinary discussion, as treatment alternatives including aortopexy, non-­invasive ventilation, and tracheostomy tube placement have been well reported also. The above interventions in the setting of future airway growth and improving structural integrity have also been met with success [40]. In some cases, airway obstruction may occur after surgical correction of airway reconstruction, congenital vascular anomalies (vascular sling, extrinsic compression, enlarged vasculature), Kommerell’s diverticulum, or bronchogenic cyst [41]. Herein, we will describe common endoscopic interventions with a focus on the pediatric population. As some of the literature in pediatric CAO is limited, we will present data regarding adult use as needed.

Dilation Procedures

Airway dilation procedures can be performed for central airway obstruction (CAO) related to stenosis, often intraluminal and non-malignant. Dilation is often accomplished with balloon equipment or the barrel of a rigid tracheoscope/ bronchoscope (Fig. 38.4).

a

Balloon dilation can be performed utilizing specially designed controlled radial expansion balloons, which are inflated under pressure to a corresponding size. These non-conformal balloons can be filled with radiopaque fluid or with saline depending on preference and planned use of fluoroscopic guidance. Other balloon techniques are reported, often utilizing conformal balloons (vascular embolectomy catheters [42], urinary catheters [43], etc.). The authors do not routinely recommend their use in adults (due to their inability to deliver a standard and uniform balloon size and distribution), however suspect their use in pediatrics may relate to difficulty obtaining non-conformal balloons that will accommodate pediatric airways.

The likely most common indication for dilation procedures in children remains subglottic stenosis, potentially from intubation and tracheostomy complications. Data exist for balloon dilation as small retrospective series in children ranging from 1 month of age to young adults [44, 45] with success rates ranging from 57–98%. Despite the general reported success of the procedure, it is also reported that many require repeat dilation procedures [46]. Less commonly reported uses include palliation of pediatric malignant CAO [9], and airway clearance adjuncts. Reports of using balloon dilation to improve airway patency exist in both obstruct-

b

ing brinous tracheal pseudomembrane [29] and foreign body aspiration [47].

Thermal Techniques

Thermal techniques utilize energy to cause tissue destruction via vaporization, cauterization, and/or coagulation (Figs. 38.5 and 38.6). One of the most

commonly used thermal energy techniques utilized for airway obstruction is the endobronchial laser. Laser therapies are currently available in different wavelengths and sizes, and are commonly reported as Neodymium: Yttrium-­Aluminum-­ Garnet, Carbon Dioxide, and Potassium-Titanium- Phosphate. Other options for thermal destruction include direct contact electrocautery, as well as argon plasma coagulation (APC).

Fig. 38.5  Thermal destruction technique for endobronchial disease utilizing electrocautery. (a) Endoscopic view of endobronchial lesion within the right mainstem causing airway obstruction in an 18-year-old boy with persistent cough and sarcoma. Endobronchial use of electrocautery

snare as it is being deployed within the airway. (b) Snare is fully deployed, encircling exophytic portion of lesion. (c) Endoscopic view immediately after removal. Patency is signi cantly improved after debulking/removal of intrinsic disease has been done, with minimal bleeding

Fig. 38.6  Thermal destruction technique for endobronchial disease utilizing argon plasma coagulation (APC). (a) Bleeding tumor emanating from right upper lobe ori-

ce. (b) Improvement in hemostasis after generous application of APC to tumor

The majority of children undergo thermal destruction of airway lesions related to non-­ malignant etiologies. Laser use is well represented in case series and observational cohorts, but no randomized studies are available for direct comparison or the lasers themselves or of alternative treatments. Laser destruction/resection of lesions is reported in granulation tissue [48–50], subglottic cysts [51–53], and hemangiomas [54, 55]. Most reports offer successful conclusions, although some report recurrent disease and unsuccessful tracheostomy tube decannulation [48].

Complications have also been reported, but retrospective trial design and lack of follow-up likely lead to selection bias in reporting. Major complications such as death and airway re have been reported, however appear rare. Mild granulation tissue and subglottic stenosis have been reported in some series [51, 55].

Successful palliation of malignancy-related CAO has been reported with both the laser and APC, with no reported complications during the procedure [9, 56]. There was one reported intraoperative death, thought to occur during an inadvertent tissue fap created during repeat fexible bronchoscopy for recurrent tumor, leading to airway obstruction and asphyxiation. The authors

a

comment on their early use of fexible bronchoscopy, noting that since all procedures are performed with rigid bronchoscopy [56].

Mechanical Debridement

Mechanical debridement techniques involve removing tissue with forceps (Fig. 38.7) or other steel instruments to improve airway patency. The main limitation to performing mechanical debridement is that it requires the presence of intrinsic airway obstruction, whereas the presence of pure extrinsic (i.e., endoluminal compression from mass) disease is a contraindication. The instruments utilized for mechanical debridement can range from fairly straightforward (tip and barrel of rigid bronchoscope) to the more complex (automated microdebrider instrument).

The use of mechanical debridement appears successfully reported in pediatric non-malignant CAO, including descriptions of use in suprastomal granulation tissue management [48] as well as tuberculosis granulomata [57]. Additionally, it can also play a role in malignant obstruction [9, 48].

Complications overall for mechanical debridement do exist, and can be major, such as bleeding,

b

Fig. 38.7  Mechanical debridement of endobronchial tumor. (a) Rigid bronchoscopic view of an endobronchial mass obstructing the right mainstem bronchus. Optical cup forceps are open on the tumor. (b) After some initial

mechanical debridement, grasping of the mass allowed for removal. Endoscopic view of large mass being withdrawn through the barrel of the rigid bronchoscope