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Friday, December 17, 2021

Modified Microcoil for Preoperative Localization of Solitary Pulmonary Nodules: A Prospective, Single-Arm, Multicenter Clinical Study

Modified Microcoil for Preoperative Localization of Solitary Pulmonary Nodules: A Prospective, Single-Arm, Multicenter Clinical Study

Clinical Question:
What is the efficacy and safety of the modified microcoil device for use in precise preoperative localization of solitary pulmonary nodules (SPNs) prior to video-assisted thorascopic surgery (VATS)?

Take Away Point:
Image-guided percutaneous placement of the modified microcoil device can facilitate efficient thorascopic resection of SPNs.

Modified Microcoil for Preoperative Localization of Solitary Pulmonary Nodules: A Prospective, Single-arm, Multicenter Clinical Study. Zhang, Zhiyuan, et al. Journal of Vascular and Interventional Radiology. 2021; 32: 1470-1477. doi.org/10.1016/j.jvir.2021.06.026.

Click here for abstract

Study Design:
Prospective, single-arm, multicenter clinical study.

Funding Source:
Beijing Municipal Science & Technology Commission, Capital Funds for Health Improvement and Research, and Beijing Municipal Administration of Hospitals Clinical Medicine Development of Special Funding Support.

Three (3) Institutions; (1) Beijing Friendship Hospital, Capital Medical University, China. (2) The First Affiliated Hospital of Bengbu Medical College, Bengbu, China. (3) Nantong Tumor Hospital, Nantong, China.


Video-assisted thorascopic surgery (VATS) is a minimally invasive option for malignant lung tumor removal. However, a large percentage of solitary pulmonary nodules (SPNs) are not localized or palpated during VATS, particularly non-solid/semisolid nodules, of which up to 78% have been reported to contain malignancy. Localization of SPNs prior to surgery can significantly improve VATS success rate. Several techniques are currently utilized to localize pulmonary lesions before excision, including both liquid markers and solid metallic markers/hooks.

A new modified microcoil device (designed in collaboration with Cherish Medical Device; Jiangsu, China) was prospectively evaluated as a method to enhance preoperative SPN coil localization. The device (Figure 1) involves partial insertion of the microcoil within the lung parenchyma, with its tail placed above the visceral pleura (Figure 2).

The prospective, multi-center study included 96 consecutive patients (96 PMNs) from 3 medical centers who underwent CT-guided SPN localization. Inclusion criteria included patients aged 18-75 years with peripheral lung nodules (diameter ≤ 2cm). Patients were excluded if they were deemed unsuitable secondary to clinical limitations, severe systemic disease, organ failure, or coagulation disorders.

Primary outcomes were measured as both technical and clinical success. (1) Technical success was defined as microcoil deployment within 10 mm of lesion edge and (2) Clinical success was defined as successful microcoil positioning with visual confirmation during VATS, lack of microcoil dislodgement or displacement, and maintained coil integrity during excision. Secondary outcomes were safety, including complications during deployment and any adverse device-related events.

Technical success rate was 100% and clinical success rate was 96.9% (95% CI, 91%-99%); all 96 nodules were successfully resected during VATS. Microcoil dislodgement occurred in 3 patients, likely due to nodule proximity to the visceral pleura. The complication rate was 1% with  asymptomatic pneumothorax not requiring intervention (minor complication) incurred in 1 patient and no major complications otherwise. All nodules were resected. No major complications or cancer recurrences were observed 90 days following excision.


The authors conclude that the new modified microcoil device is safe and effective for SPN localization prior to VATS, with a reported localization success rate of 96.9% and SPN resection rate of 100%, without the need for fluoroscopy.

Specifically, the authors highlight features of the microcoil device including a helical tail to clearly mark the pleural surface without the need for fluoroscopy, a push rod with marking scale allowing rapid and accurate deployment, and microcoils of various lengths to compensate for SPN location variability.

Techniques for pulmonary nodule needle localizations have been previously described and typically involve wire-localization with the modified hook needle technique (e.g. Kopans, Hawkins) and/or methylene blue staining. However these techniques could only be utilized in the immediate pre-procedural setting. This device allowed for much more flexibility in the timing of surgical excision (e.g. following-day VATS) while maintaining a very low complication rate.

The reported results illustrating the safety and effectiveness of the new modified microcoil device are promising. However, the study was not without its limitations. Learning curve was not evaluated. Only patients with solitary lung nodule were included in the study. And most importantly, there was no comparison group and therefore the comparative benefits of this device and its associated technique could not be evaluated. Large-scale, randomized clinical trials are needed to determine whether the modified microcoil has advantages over other devices such as conventional microcoils and hook wires

Additional Ref:
Thistlethwaite, P. A., Gower, J. R., Hernandez, M., Zhang, Y., Picel, A. C., & Roberts, A. C. (2018). Needle localization of small pulmonary nodules: Lessons learned. The Journal of Thoracic and Cardiovascular Surgery, 155(5), 2140–2147. https://doi.org/10.1016/j.jtcvs.2018.01.007

Post Author:
Noam Kupfer, MD (PGY-3)
Vascular & Interventional Radiology (Integrated) Residency, Class of 2025
Rush University Medical Center

David M. Tabriz, MD
Assistant Professor - Vascular & Interventional Radiology
Program Director - Vascular & Interventional Radiology (Integrated) Residency
Program Director - Vascular & Interventional Radiology (Independent) Residency
Rush University Medical Center

Edited and formatted by @NingchengLi
Interventional Radiology Resident
Dotter Institute, Oregon Health and Science University

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