Flexible endoscopy for pediatric tracheobronchial metallic stent placement, maintenance and long-term outcomes

Abstract

Objectives: To assess the placement, surveillance management and long-term outcomes of the tracheobronchial (TB) balloon expandable metallic stent (BEMS) managed by therapeutic flexible endoscopy (TFE).

Methods: This is a retrospective review and analysis of all computerized medical records and related flexible endoscopy videos of pediatric patients who received TB BEMS during 20 years period, from January 1997 to December 2016. TFE techniques with forceps debridement, balloon dilatation and laser ablation were used to implant stents, perform regular surveillance, maintain their functions, and expand the diameters of BEMS. Short-length (30cm-36cm) endoscopes of OD 3.2mm to 5.0mm coupled with the noninvasive ventilation, without ventilation bag, mask or airway tube, supported the whole procedures.

Results: 146 BEMS were implanted in 87 consecutive children, including 84 tracheal, 15 carinal and 47 bronchial stents. At the time of placement, the mean age was 35.6 ± 54.6 month-old (range 0.3-228) and the mean body weight was 13.9 ± 10.6 kg (range 2.2-60). Surveillance period was 9.4 ± 6.7 years (range, 0.3-18.0). Satisfactory clinical improvements were noted immediately in all but two patients. Seventy-two (82.8%) patients were still alive with stable respiratory status, except two patients necessitating TFE management every two months. Fifty-one stents, including 35 tracheal and 16 bronchial ones, were successfully retrieved mainly with rigid endoscopy. Implanted stents could be significantly (< .001) further expanded for growing TB lumens. The final stent diameters were positively correlated to the implanted duration. Altogether, 33 stents expired (15 patients), 51 were retrieved (40 patients), and 62 remained and functioning well (38 patients), with their mean duration of 7.4 ± 9.5, 34.9 ± 36.3 and 82.3 ± 62.5 months, respectively.

Conclusion: In pediatric patients, TFE with short-length scopes coupled with this NIV support has provided a safe, feasible and effective modality in placing and subsequently managing TB BEMS with acceptable long-term outcomes.

Fig 1. Sequential steps of stent implantation in severe tracheomalacia by flexible endoscopy.

a) Tracheomalacia; b) inserting stent via larynx; c) positioning stent; d) inflating the stent; e) Deflating the balloon; f) Final stent.

Fig 2. Diagram of “nasopharyngeal oxygen with intermittent nose-closure” ventilation.

Done alone (a), or coupled with therapeutic flexible bronchoscopy (b).

Fig 3. Picture of an infant undergoing therapeutic flexible bronchoscopy supported with this noninvasive ventilation maneuver.

A nasopharyngeal oxygen catheter inserted into right nostril, a balloon catheter via mouth and a flexible endoscope via left nostril.

Fig 4. Anatomic locations of tracheobronchial stents.

Implanted (a) and retrieved (b) stents.

Fig 5. Laser ablation of stent-associated granulation with flexible endoscopy.

Fig 6. Balloon dilatation plasty.

Which could simultaneously compressing stent-associated granulation and expanding the stent with flexible endoscopy.

Fig 7. Sequential steps of stent retrieval.

(a) Inserting a guidewire in the gap between the stent and mucosal wall; (b) mounting and advancing balloon catheter through the guidewire; c) inflating the balloon to separate the stent from the mucosa; d) the destroyed stent becoming easier for grasping by forceps during retrieval procedure.