Augmented fluoroscopy guided transbronchial pulmonary microwave ablation using a steerable sheath

Abstract

Background: Transbronchial microwave ablation (MWA) is a promising novel therapy. Despite advances in bronchoscopy and virtual navigation, real time image guidance of probe delivery is lacking, and distal maneuverability is limited. Cone-beam computed tomography (CBCT) based augmented fluoroscopy guidance using steerable sheaths may help overcome these shortcomings. The aim of this study was to evaluate feasibility and accuracy of augmented fluoroscopy guided transbronchial MWA with a steerable sheath and without a bronchoscope. Methods:In this prospective study, procedures were performed under general anesthesia. Extra-bronchial lung synthetic targets were placed percutaneously. Target and airways extracted from CBCT, with planned bronchial parking point close to the target were overlaid on live fluoroscopy. Endobronchial navigation was solely performed under augmented fluoroscopy guidance. A 6.5 Fr steerable sheath was parked in the bronchus per plan, and a flexible MWA probe was inserted coaxially then advanced through the bronchus wall towards the target. Final in-target position was confirmed by CBCT. Only one ablation of 100 W-5 min was performed per target. Animals were euthanized and pathology analysis of the lungs was performed.Results: Eighteen targets with a median largest diameter of 9 mm (interquartile range, 7-11 mm) were ablated in 9 pigs. Median needle-target center distance was 2 mm (interquartile range, 0-4 mm), and was higher for lower/middle than for upper lobes [0 mm (interquartile range, 0-4 mm) vs. 4 mm (interquartile range, 3-8 mm), P=0.04]. No severe complications or pneumothorax occurred. Two cases of rib fractures in the ablation zone resolved after medical treatment. Median longest axis of the ablation zone on post-ablation computed tomography was 38 mm (interquartile range, 30-40 mm). Histology showed coagulation necrosis of ablated tissue. Conclusions: Transbronchial MWA under augmented fluoroscopy guidance using a steerable sheath is feasible and accurate.

Pigs: Large Animal Preclinical Cancer Models

“…for lung cancer pRosa26-iCas9 pigs by intra-nasal delivery Chinese Bama mini-pigs [60] Endovascular and percutaneous (biopsy plus incubation with AdCre ex vivo followed by inoculation) delivery [61] Microwave ablation Oncopigs [54][55][56] Conventional vs. cone beam CT to monitor microwave ablation [57] Xenogeneic cross-circulation to support human donor [58,59] disease and amyotrophic lateral sclerosis (ALS) compared to rats, while pig and mice brains have decreased levels of secretagogin (SGCN) -a protein expressed in the olfactory bulb, compared to humans [65,66]. Once again placing importance on proteome profiles to choose an animal model most appropriate for translational research [67] to recapitulate tissue-specific needs.…”

“…Due to the similarity between pig and human lungs, pigs have been extensively used for trialing minimally invasive procedures such as microwave ablation [54][55][56], understanding the differences in conventional versus cone beam CT-based monitoring techniques [57], and understanding xenogeneic cross-circulation to support human donor lung ex vivo [58,59]. With the advancement of genetic modifications techniques and availability of whole pig genome sequencing data, genetic lesions in vivo can be recapitulated to understand tumor development.…”

Transbronchial cryoablation in peripheral lung parenchyma with a novel thin cryoprobe and initial clinical testing

“…Good safety and efficacy have been shown based on a limited number of participants. [10][11][12][13][14] Therefore, further evaluation in larger cohorts is still warranted. Our team developed a 2.2mm-wide flexible cryoprobe (Y2212, AccuTarget MediPharma (Shanghai) Co., Ltd) that fitted through bronchoscopy working channels and evaluated its feasibility and safety ex vivo and in…”

Chinese expert consensus on cone‐beam CT‐guided diagnosis, localization and treatment for pulmonary nodules

“…In ablation procedures, CBCT can also be used for treatment monitoring and evaluating ablation efficacy 28–30 . Some CBCT systems can provide augmented fluoroscopy to guide the tools to target lesions 31–33 . Based on the fixed CBCT system, the path from the puncture point on skin to target lesion can be planned and used for real‐time guidance during PTNB procedures 34 .…”

“… 28 , 29 , 30 Some CBCT systems can provide augmented fluoroscopy to guide the tools to target lesions. 31 , 32 , 33 Based on the fixed CBCT system, the path from the puncture point on skin to target lesion can be planned and used for real‐time guidance during PTNB procedures. 34 Compared with conventional CT, the CBCT system provides 3D and fluoroscopic images in real time.…”