Electromagnetic Navigation Transthoracic Nodule Localization for Minimally Invasive Thoracic Surgery

Summary

Presented here is a protocol for lung nodule localization using dye marking via electromagnetically navigated transthoracic needle access. The technique described here can be accomplished in the peri-operative period to optimize nodule localization and to successful resection when performing minimally invasive thoracic surgery.

Abstract

The increased use of chest computed tomography (CT) has led to an increased detection of pulmonary nodules requiring diagnostic evaluation and/or excision. Many of these nodules are identified and excised via minimally invasive thoracic surgery; however, subcentimeter and subsolid nodules are frequently difficult to identify intra-operatively. This can be mitigated by the use of electromagnetic transthoracic needle localization. This protocol delineates the step-by-step process of electromagnetic localization from the pre-operative period to the postoperative period and is an adaptation of the electromagnetically guided percutaneous biopsy previously described by Arias et al. Pre-operative steps include obtaining a same day CT followed by the generation of a three-dimensional virtual map of the lung. From this map, the target lesion(s) and an entry site are chosen. In the operating room, the virtual reconstruction of the lung is then calibrated with the patient and the electromagnetic navigation platform. The patient is then sedated, intubated, and placed in the lateral decubitus position. Using a sterile technique and visualization from multiple views, the needle is inserted into the chest wall at the prechosen skin entry site and driven down to the target lesion. Dye is then injected into the lesion and, then, continuously during needle withdrawal, creating a tract for visualization intra-operatively. This method has many potential benefits when compared to the CT-guided localization, including a decreased radiation exposure and decreased time between the dye injection and the surgery. Dye diffusion from the pathway occurs over time, thereby limiting intra-operative nodule identification. By decreasing the time to surgery, there is a decrease in wait time for the patient, and less time for dye diffusion to occur, resulting in an improvement in nodule localization. When compared to electromagnetic bronchoscopy, airway architecture is no longer a limitation as the target nodule is accessed via a transparenchymal approach. Details of this procedure are described in a step-by-step fashion.

Introduction

With the increasing use of CT scans of the chest for diagnostic and screening purposes¹, there is an increased detection of subcentimeter pulmonary nodules requiring diagnostic evaluation². Percutaneous and/or transbronchial biopsy have been successfully used to sample indeterminate and high-risk nodules. These lesions often make for challenging targets due to their distal parenchymal location and small size³. When indicated, surgical excision of these lesions should be performed, using a lung-sparing resection via minimally invasive thoracic surgery (MITS), such as video- or robot-assist....

Protocol

The procedure is performed in accordance with standard of care expectations and follows the guidelines of the human research ethics committee at the University of North Carolina at Chapel Hill.

1. Pre-operative Preparation

1. Review prior chest computed tomography (CT) imaging to ensure that the patient undergoing nodule localization has a peripheral pulmonary nodule suitable for minimally invasive thoracic surgery (MITS).
2. On the day of or a day prior to the procedure, perform a noncontrast chest CT scan with the patient in the lateral decubitus position with the lung ipsilateral to the nodule positioned up to mimic the p....

Results

The patient was prepared per the protocol noted above. Following this, EMTTNL was performed with an injection of a total of 1 mL of a 1:1 methylene blue:patient blood mixture. Upon removal of the needle, the patient was prepped and draped for MITS. Robot-assisted thoracic surgery was performed using the four-arm technique with a robotic surgical system using five total ports. Four ports are placed along the eighth intercostal space (each 9 cm apart) anteriorly from the midclavicular line .......

Discussion

Peri-operative transthoracic nodule localization under EMN guidance is a novel application of a recently introduced EMN platform. The critical steps in the performance of EMTTNL are a proper point cloud registration of the device and attentiveness to the percutaneous insertion site and the angulation of the needle. Visualization and maintenance of the angle of entry on multiple planes of the CT scan (HUD, oblique 90, and oblique) are crucial to the success of the procedure.

Some of the followi.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Computed Tomography Scanner			64 - detector (or greater) CT scanner
SPiN Thoracic Navigation System	Veran Medical Tecnologies	SYS 4000
SPiN Planning Laptop Workstation	Veran Medical Tecnologies	SYS-0185
SPiN View Console	Veran Medical Tecnologies	SYS-1500
Always-On Tip Tracked Steerable Catheter	Veran Medical Tecnologies	INS-0322	3.2 mm OD, 2.0 mm WC
View Optical Probe	Veran Medical Tecnologies	INS-5500
vPAD2 Cable	Veran Medical Techologies	INS-0048
vPAD2 Patient Tracker	Veran Medical Techologies	INS-0050
SPiNPerc Biopsy Needle Guide Kit	Veran Medical Techologies	INS-5600	Includes INS 5029 (Box of 5)
ChloraPrep applicator	Beckton Dickinson	260815	26 mL applicator (orange)
Provay/Methylene Blue	Cenexi/American Regent	0517-0374-05	50 mg/10 mL
Sterile gloves	Cardinal Health	2D72PLXXX
Blue X-Ray O.R. Towels	MedLine	MDT2168204XR
Scope Catheter	DSC		3.2 mm outer diameter, working channel 2.0