AIM (Anticipate/Adjust, Image, Manage) to Prevent Bleeding During Robotically‐Assisted Bronchoscopic Ablation

ABSTRACT

Therapeutic treatment of lung nodules by ablation is a new field. Even though not considered standard of care, lung nodule ablation can be appropriate for select cases. Even though ablation is a safe and well‐tolerated procedure, bleeding is a potential complication. We introduce our stepwise approach through two cases on how we AIM (Anticipate/Adjust, Image, Manage) to prevent uncontrolled bleeding during Robotically Assisted Bronchoscopic Ablation: 1. Anticipate structures with high risk for bleeding and adjust accordingly, accounting for the needle ablation field; 2. Image: utilise cone beam CT before the first and after each ablation session to screen for bleeding; 3. Manage bleeding by pre‐emptively utilising Fogarty balloon occlusion.

We introduce our stepwise approach on how we AIM (Anticipate/Adjust, Image, Manage) to prevent severe, uncontrolled bleeding during Pulsed Electrical Field Robotically Assisted Bronchoscopic Ablation (PEF‐RABA): 1. Anticipate structures with high risk for bleeding and adjust accordingly, accounting for the needle ablation field. 2. Image: utilise cone beam CT before the first and after each ablation session to screen for bleeding. 3. Manage bleeding by pre‐emptively utilising Fogarty balloon occlusion.

1. Introduction

Therapeutic treatment of lung nodules by local ablation is a newly emerging field. Ablative modalities include heat (microwave), cold (cryoablation), pulsed electric field (PEF) or radioactivity [1]. These ablative methods are not considered standard of care (SOC) treatments for primary lung cancers; however, they have been studied in specific scenarios such as inoperable candidates, chemo/immunotherapies or radiation scenarios, or patients with multiple comorbidities. Despite this limitation, Robotically‐Assisted Bronchoscopic Ablation (RABA) may still have a role in oligometastatic disease, extra thoracic malignancies [2] and bronchial carcinoid [3]. PEF ablation (also known as Irreversible Electroporation) is a non‐thermal ablative modality. It uses a catheter to create a short‐lived strong electrical field around itself, causing microscopic irreversible pores in cell membranes (electroporation). This leads to the loss of the cell's ability to maintain its homeostasis, eventually causing cell death [1]. Ablation‐related bleeding and subsequent haemoptysis are expected complications of which the frequency and rate of presentation remain uncertain [2]. Overall, ablation is a safe and well‐tolerated procedure [4, 5]. Nonetheless, severe airway bleeding is a serious, potentially life‐threatening complication during bronchoscopic procedures, which can carry high mortality rates. Bleeding prevention strategies are essential to maximise patient safety [6]. We believe our bronchoscopic approach can prevent uncontrolled, life‐threatening airway bleeding and maximise patient safety during bronchoscopic ablative therapies. This manuscript specifically describes our approach for severe bleeding prevention during Robotically RABA.

2. Case Report

76‐year‐old former smoker (10 pack year, quit 28 years ago) woman with a history of breast cancer presented with a chronic cough. She was found to have multiple lung nodules consistent with diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH). The diagnosis was confirmed, previously, through shape sensing Robotic Assisted Bronchoscopy (ssRAB) sampling a 7.3 × 8.6 mm dominant left upper lobe (LUL) nodule (Figure 1.) in which mediastinal and hilar staging was also negative for malignancy. Due to her DIPNECH diagnosis, she was not treated with a surgical approach, and the patient opted for bronchoscopic ablation. We performed PEF‐RABA on her dominant LUL nodule as follows:

FIGURE 1.

Patient 1. Axial CT chest showing the measurements of the right upper lobe carcinoid prior to pulsed electric field (PEF) ablation.

Pre‐procedural planning was essential given the proximity of the nodule to relevant vascular structures as detailed in image 2. The aortic arch was about 6.6 mm away from the medial border of the target lesion, and the nodule had 2 additional blood vessels around it (Figures 2, 3, 4). Given the expected PEF ablative field, we anticipated two activation vectors with the ablative needle. We subsequently proceeded with ssRAB through a 7.5 mm endotracheal (ET) tube and navigated until we wedged peripherally at 2 mm from the virtual target. Concentric radial signal was confirmed utilising radial endobronchial ultrasound. The 21‐gauge ablation needle was introduced (see ablative field measurements in Discussion and on Figure 11), and optimal needle position was confirmed utilising mobile Cone Beam CT (mCBCT), Figure 5. The first ablative vector was activated, the needle retracted, and repositioned for a second vector. Optimal second vector location was also confirmed with mCBCT. Of note, every mCBCT spin was an opportunity to evaluate bleeding and local blood expansion.

FIGURE 2.

Patient 1. Axial CT chest of lung nodule with all significant vessels (zoomed in).

FIGURE 3.

Patient 1. Coronal CT chest of lung nodule with vessel (zoomed in).

FIGURE 4.

Patient 1. Sagittal CT chest of lung nodule with vessel (zoomed in).

FIGURE 11.

The ablation field of the pulsed electric field ablation needle (Galvanise Therapeutics, San Carlos, CA, USA).

FIGURE 5.

Patient 1. Cone beam CT image showing the ablation tool in the nodule.

Given the proximity of the previously described vascular structures, and the bleeding noted during the mCBCT, we opted for an additional bronchoscopic strategy to limit potential bleeding. Before unwedging the robotic arm, we introduced a therapeutic disposable bronchoscope (Ambu Scope 5, outer diameter 5.6 mm, working channel 2.8 mm) through the mouth and parallel to and outside the ET tube, into the subsegment where the robotic arm was wedged. Under direct visualisation of the robotic arm, we introduced a Fogarty balloon parallel to the robotic scope (Figure 6). We slowly retracted the robotic bronchoscope from the wedged position under direct visualisation through the therapeutic disposable bronchoscope and inflated its balloon to prevent blood spillage (Figure 6). The robotic arm was completely retracted and the balloon subsequently confirmed with no active bleeding bronchoscopically.

FIGURE 6.

Patient 1. Fogarty balloon and robotic scope in the airway.

Our second case is a 73‐year‐old former smoker woman (23 pack year, quit 39 years ago), presenting with a biopsy‐proven, 7.5 × 9.4 mm typical carcinoid in the left lower lobe (LLL) (Figure 7.), as well as an undiagnosed 52.8 × 29.8 mm right upper lobe (RUL) irregular, mixed‐density lesion. Given the high pre‐test probability of RUL adenocarcinoma requiring lobectomy, we had a detailed discussion of risks and benefits. The patient opted for bronchoscopic ablation of the LLL carcinoid nodule if the RUL lesion was confirmed to be adenocarcinoma. Consequently, we performed PEF‐RABA of the LLL carcinoid with the previously detailed technique (see ablative field measurements in Discussion and on Figure 11). Blood vessel proximity is detailed on Figure 8. Using mCBCT, we confirmed tool in‐lesion with the 21‐gauge ablation needle (Figure 9). This nodule was treated with one activation. The same precautionary strategy from the first case was used (Figure 10) and minimal residual bleeding was noted.

FIGURE 7.

Patient 2. Pre‐ablation CT image of the left lower lobe, biopsy‐proven carcinoid showing the target nodule measurements.

FIGURE 8.

Patient 2. Coronal CT zoomed in to show the abutting small vessel to the nodule.

FIGURE 9.

Patient 2: Cone beam CT image showing the image of tool in‐lesion (zoomed in).

FIGURE 10.

Patient 2: Fogarty balloon next to the robotic bronchoscope in the airway.

Both patients were observed in hospital for 24 h. For patient 1, 3 weeks post‐procedure CT showed the treated nodule has decreased in size from 7 mm to 4 mm. For patient 2, the 2 month chest CT showed reduction of the nodule to 7 mm (from prior 9 mm). The plan is for both patients to continue monitoring in the outpatient setting and return for follow‐up at 3 months with repeat chest CT. We consider the results of the ablation satisfactory as the nodules shrunk in both cases post‐ablation. Longer‐term follow‐up is in place to confirm if initial, short‐term post‐procedure response is maintained. There was no immediate or long‐term severe or non‐severe complication related to the ablation in either of the cases including severe airway bleeding or pneumothorax.

3. Discussion

These two cases illustrate the importance of preventing uncontrolled bleeding during PEF RABA and provide step‐by‐step guidance on how to proceed with targets that have a high bleeding risk. Here, we introduce our stepwise approach on how we AIM (Anticipate/Adjust, Image, Manage) to prevent uncontrolled bleeding during PEF‐RAB.

1. Anticipate structures with high risk for bleeding and adjust accordingly, accounting for the needle ablation field.

2. Image: utilise cone beam CT before the first and after each ablation session to screen for bleeding.

3. Manage bleeding by pre‐emptively utilising Fogarty balloon occlusion. Note the importance of combining a smaller ET tube and a smaller outer diameter bronchoscope but with a large therapeutic working channel with this disposable bronchoscope.

We believe pre‐procedure planning is essential to limit the proximity of the ablative field with relevant blood vessels. For both cases in this case report we used the INUMI Flex PEF ablation needle (Galvanise Therapeutics, San Carlos, CA, USA) which has a 21‐gauge needle, with 5 mm of exposed electric surface, which creates an ablation field of approximately 11 ± 1 mm by 14 ± 2 mm (Figure 11). Each activation lasted for 5 min.

Second, we recommend diligent monitoring for bleeding during the procedure with mCBCT. We utilised every spin to confirm tool‐in‐lesion as an opportunity to assess for bleeding. An additional mCBCT prior to unwedging is also recommended. Third, we recommend a smaller ET tube, compared to traditional ssRAB cases, and a smaller OD therapeutic bronchoscope to maximise the use of a Fogarty catheter through the working channel. Alternatively, starting the procedure by intubating with a Fogarty balloon outside the ET tube or placing a Fogarty balloon using a flexible bronchoscope next to the ET tube post‐intubation are reasonable approaches. Upon unwedging, the robotic arm should be cautiously retracted, and the balloon of the Fogarty catheter reinflated if brisk bloody return is noted. We chose the larger diameter disposable bronchoscope in case we encountered severe airway bleed, as we have a larger suction power available to better control the bleeding. This disposable scope was advanced outside the ET tube, which required a second team member to be present for deflating and inflating the ET tube balloon. Our disposable bronchoscope was advanced to the lobar take‐off, proximal enough to fit well in the main airways with the SSRAB and see any bleeding from a safe distance when the SSRAB was pulled back and the operator was ready to inflate the Fogarty balloon in case bleeding was noted. Once inside the main airway, visualising the route of the SSRAB bronchoscope and advancing a Fogarty balloon to a distal, but still visible airway, we reinflated the ET tube balloon. We believe these strategies can mitigate any potential severe bleeding and maximise patient safety during high‐risk bleeding cases treated with any endobronchial ablation technique.

Author Contributions

All persons listed as authors should qualify for authorship as defined by the ICMJE. Sebastian Fernandez‐Bussy, Anna Kornafeld, Bryan Husta, Linh H. Vu, Alejandra Yu Lee‐Mateus, Mohammed A. Alqawasma, David Abia‐Trujillo participated in the conception or design of the work, the acquisition, and interpretation of data for the work. Anna Kornafeld drafted the work, and Sebastian Fernandez‐Bussy, Anna Kornafeld, Bryan Husta, Linh H. Vu, Alejandra Yu Lee‐Mateus, Mohammed A. Alqawasma, David Abia‐Trujillo participated in reviewing the manuscript critically for important intellectual content. Sebastian Fernandez‐Bussy, Anna Kornafeld, Bryan Husta, Linh H. Vu, Alejandra Yu Lee‐Mateus, Mohammed A. Alqawasma, David Abia‐Trujillo gave final approval of the version of this manuscript to be published.

Ethics Statement

The authors declare that written informed consent was obtained for the publication of this manuscript and accompanying images using the consent form provided by the Journal.

Conflicts of Interest

The authors declare no conflicts of interest.

Fernandez‐Bussy S., Kornafeld A., Husta B., et al., “ AIM (Anticipate/Adjust, Image, Manage) to Prevent Bleeding During Robotically‐Assisted Bronchoscopic Ablation,” Respirology Case Reports 13, no. 9 (2025): e70335, 10.1002/rcr2.70335.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.