Single-Use Flexible Bronchoscope in Facilitating Endobronchial Valve Treatment in Severe Emphysema

Introduction

The Zephyr endobronchial valve (EBV; Pulmonx Corp., Redwood City, CA, USA) is an implantable device designed to occlude the segmental and lobar bronchi in the most destructed lobe of the lung in emphysema patients in order to achieve complete lobar collapse. When placed correctly, EBV induces a full lobar collapse, thereby reducing hyperinflation, which manifests in clinical improvement.¹ However, we sometimes encounter anatomical challenges in placing the valves in the appropriate position due to acute angled bronchial bifurcation, particularly in the apical segments. Here, we present a successful bronchoscopic lung volume reduction (BLVR) case with EBVs performed using a single-use flexible bronchoscope, which offers much greater flexion and extension than traditional reusable therapeutic bronchoscopes.

Case Report/Case Presentation

A 56-year-old woman with severe emphysema was referred to our hospital after an incomplete EBV treatment due to a very sharp bronchial bifurcation angle of the right upper lobe apical segment (RB1). The initial right upper lobe EBV procedure was also complicated by an intraprocedural small right-sided pneumothorax, which did not require further interventions but was presumed to reflect the difficulties encountered during the initial procedure. The initial pre-procedure chest CT quantification showed a heterogenous emphysema distribution, with a right upper lobe treatment target with 46% of the voxel density less than −950 hU, and a total right upper lobe fissure completeness score of 98%. The absence of collateral ventilation was confirmed during the initial procedure by Chartis (PulmonX, Pulmonx Corp., Redwood City, CA, USA), which is an assessment tool for collateral ventilation with a pressure-flow transducer balloon catheter. The chest CT on arrival of the patient in our hospital showed a full recovery of the pneumothorax as well as the insertion of three Zephyr valves in the right upper lobe segments (RB1a1, RB2, and RB3), with the valve in the RB1a1 being placed too distal leaving the RB1a2 and RB1b open. We performed bronchoscopy using 1TH190 (Olympus) under general anesthesia. On inspection, the EBV inserted in RB3 was appropriately placed, the valve in RB2 was misaligned, solved by gentle removal and re-insertion of a new 4.0 valve in the same segment. After this, the too distally placed valve in RB1a1 was removed. At that time, it already became apparent that RB1b would be difficult to reach, with a too short and much too wide landing zone for just a single RB1 valve placement. We first attempted to approach RB1b for sizing with a 5.5 endobronchial delivery catheter (EDC, Pulmonx Corp., Redwood City, CA, USA), but advancing the catheter to the subsegment was difficult due to the steep bronchial bifurcation angles. We then re-attempted to reach the target subsegment by bending the catheter and carefully maneuvering the bronchoscope; however, it remained inaccessible. Therefore, we switched to a single-use bronchoscope (Ambu^® aScope™ 5 Broncho HD 5.6/2.8, Ambu A/S, Ballerup, Denmark) with a more flexible tip, as shown in Figure 1A and B. This change finally enabled us to reach the location and successfully place a 5.5 LP valve in RB1b. After that, we inserted a new 4.0 LP valve in RB1a, completing the placement of valves in all target lobe segments. The post-procedural chest X-ray already showed partial lung volume reduction of the right upper lobe, with no recurrence of the pneumothorax. The patient was discharged uneventfully after three days.

Figure 1 Comparison of the bending range between a reusable therapeutic bronchoscope and a disposable therapeutic bronchoscope. (A) upward bending, (B) downward bending.

Discussion

Achieving significant lung volume reduction is crucial for obtaining clinical benefits from BLVR with EBVs. To achieve this, it is necessary to confirm the absence of collateral ventilation and to properly place valves in all segments or subsegments of the target lung for complete lobar occlusion.²

However, we sometimes encounter challenging anatomical situations in cases where placing the valves in the appropriate position is difficult. Although the important procedural considerations and techniques related to EBV placement have been previously reported, placing the valve in the ideal position can sometimes be challenging due to patient anatomy.² In our experience, the apical segments of the lobe can sometimes be difficult for catheter delivery and valve placement due to steep bronchial bifurcation angles. When a 4.0 EBV is of the appropriate size, delivery is facilitated by the use of a J-type 4.0 EDC. However, if a 5.5 EBV is required, alternative strategies are required. The Zephyr EDC requires therapeutic bronchoscopes with a working channel of 2.8 mm or larger. Although currently available reusable therapeutic bronchoscopes have a bending range of up to 180° for upward angulation and up to 130° for downward angulation, some of the recently introduced single-use therapeutic bronchoscopes offer a bending range of up to 195° to 210° for both upward and downward angulation,³ as summarized in Table 1.

Table 1 List of Therapeutic Bronchoscopes

In this case, we used a single-use therapeutic bronchoscope capable of bending up to 195° in both upward and downward angles. This flexibility allowed us to successfully place a valve in a bronchus with a steep branching angle, which was in this case impossible with traditional reusable therapeutic bronchoscopes. The fact that the working channel of the reusable bronchoscope in on the right side and in our single-use on the left side might have also facilitated a somewhat easier airway access. To our knowledge, this is the first report showing the utility of single-use therapeutic bronchoscopes in BLVR with EBVs, although almost none of the major reports associated with BLVR with EBVs disclosed whether single-use or reusable bronchoscopes were used. The use of single-use therapeutic bronchoscopes with greater flexibility than conventional reusable therapeutic bronchoscopes may be a valuable approach to achieving successful EBV placement in cases with steep bronchial branching angles that are challenging to approach and is a creative addition to the interventional pulmonologists’ toolbox.⁴