Lung Navigation Ventilation Protocol to Optimize Biopsy of Peripheral Lung Lesions

Abstract

Background: Computed tomography-to-body divergence caused by respiratory motion, atelectasis, diaphragmatic motion and other factors is an obstacle to peripheral lung biopsies. We examined a conventional ventilation strategy versus a lung navigation ventilation protocol (LNVP) optimized for intraprocedural 3-dimensional image acquisition and bronchoscopic biopsy of peripheral lung nodules.Methods: A retrospective, single center study was conducted in consecutive subjects with peripheral lung lesions measuring <30 mm. Effects of ventilation strategies including atelectasis and tool-in-lesion confirmation were assessed using cone beam computed tomography images. Diagnostic yield was also evaluated. Complications were assessed through 7 days.Results: Fifty subjects were included (25 per group) with 27 nodules in the conventional group and 25 nodules in the LNVP group. Atelectasis was assessed by 2 blinded readers: [reader 1 (R1) and reader 2 (R2)]. Atelectasis was more prevalent in the conventional ventilation group, both for dependent atelectasis (R1: 64% and R2: 68% vs. R1: 36% and R2: 16%, P = 0.00014) and sublobar/lobar atelectasis (R1: 48% and R2: 56% vs. R1: 20% and R2: 32%, P = 0.01). Similarly, the target lesion was obscured due to atelectasis more often in the conventional ventilation group (R1: 36% and R2: 36% vs. R1: 4% and R2: 8%, P = 0.01). Diagnostic yield was 70% for conventional ventilation and 92% for LNVP (P = 0.08).Conclusion: LNVP demonstrated markedly reduced dependent and sublobar/lobar atelectasis and lesions either partially or completely obscured by atelectasis compared with conventional ventilation. Future prospective studies are necessary to understand the impact of protocolized ventilation strategies for bronchoscopic biopsy of peripheral lung lesions.

Anesthesia considerations to reduce motion and atelectasis during advanced guided bronchoscopy

“…After abstract and full-text review, there were 11 papers (8 original studies and 3 meta-analyses) that specifically evaluated the impact of the anesthesia method on atelectasis, safety, or diagnostic yield during advanced bronchoscopy [4,[27][28][29][30][31][32][33][34][35][36]. Bowling et al compared ENB using general anesthesia versus intravenous sedation and observed diagnostic yields of 70% and 78%, respectively (P = NS) [29].…”

“…Bowling et al compared ENB using general anesthesia versus intravenous sedation and observed diagnostic yields of 70% and 78%, respectively (P = NS) [29]. As will be described in greater detail below, Bhadra et al 2021 observed less atelectasis and a trend toward greater diagnostic yield using an optimized ventilation protocol compared to conventional ventilation [28]. Minami et al (2017) reported that fentanyl and midazolam sedation was useful for peripheral bronchoscopy [32].…”

“…The following is a recommended protocol for ventilation during advanced guided bronchoscopic biopsy (Table 1). These recommendations were derived from the anesthesia literature regarding the principles of minimizing atelectasis during positive pressure ventilation [37][38][39][40][41][42], the authors' published work [28], and the authors' combined experience of over 1000 CBCT navigation cases assessing the presences of atelectasis and CT-to-body divergence. While the use of higher PEEP and lower FiO 2 during induction may contradict traditional anesthesiology practices, they are important for guided bronchoscopy where the success of the biopsy is highly dependent upon stabilizing dependent areas of the lung during intraprocedural imaging, particularly in obese patients and those with posterior or lower lobe lesions [43,44].…”

“…However, with one exception [ 28 ], the studies described above used navigation bronchoscopy systems without intraprocedural advanced imaging. Newer systems such as tomosynthesis-based fluoroscopic navigation [ 10 ] and CT augmented fluoroscopy [ 28 ] require a breath hold to minimize lung movement during intraprocedural imaging and location adjustments.…”

“…However, with one exception [ 28 ], the studies described above used navigation bronchoscopy systems without intraprocedural advanced imaging. Newer systems such as tomosynthesis-based fluoroscopic navigation [ 10 ] and CT augmented fluoroscopy [ 28 ] require a breath hold to minimize lung movement during intraprocedural imaging and location adjustments. Furthermore, CT-to-body divergence and atelectasis are likely strong contributors to the sub-optimal diagnostic yield seen with earlier generations of navigation bronchoscopy technology in large multicenter studies [ 30 ].…”