A Novel Use of Coblation in the Treatment of Tracheal Tumors

Introduction

Most recently, the use of coblation technology has been reported in the treatment of laryngotracheal pathology. ^{1 -3} To date, these literatures are limited to laryngeal or subglottic lesions and studies on coblation for tracheal tumors in middle or lower trachea have not been reported. Here, we described a novel use of coblation technology, in which a new type of airway-specific wand was used to ablate tracheal tumors in 3 cases. The study was approved by the institutional review board of Beijing Tian Tan Hospital (approval ID: QX2016-004-02).

The new tracheal-specific wand (Jeswis Technology Ltd) used in this study is shown in Figure 1A. It is designed for precise, controlled removal of trachea lesions. The features of the tracheal-specific wand were as follows: (1) It is 55 cm in working length which is much longer than laryngeal-specific wands or soft palate wands (usually about 20 cm in working length). The extended length realizes improved access to middle or lower trachea lesions. (2) It is 3.9 mm in diameter. Its slim wand shaft increases visualization of surgical field and makes it well suited for operating on small anatomy through rigid bronchoscopy. (3) Its tip has been designed with several shapes that suit different lesions and has 4 electrodes which makes it an ideal tool for removal of bulky lesions (Figure 1B and C).

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Figure 1.

(A) The tracheal-specific wand (55 cm in working length and 3.9 mm in diameter) with saline irrigation tube. (B) A tracheal-specific wand with inclined plane tip. (C) A tracheal-specific wand with lateral plane tip. Black arrow: saline irrigation tube. White arrow: suction channel. Blue arrow: 4 electrodes at the tip.

Case Report

Case 1

A 63-year-old man who complained of dyspnea for 1 year was admitted. Initial bronchoscopy revealed a smooth tumor located on the right side of the middle trachea and showed a lobulated shape (Figure 2A). Interventional rigid bronchoscopy (Karl Storz) was subsequently performed and high-frequency jet ventilator was used for ventilation. An airway-specific wand was used to ablate the tumor (Figure 2B) until the trachea became patent and plat (Figure 2C). A minimal amount of bleeding occurred during this process. The patient had normal breathing after the procedure without complaints of discomfort and was discharged the following day. Postoperative pathology confirmed a tracheal schwannoma. A follow-up bronchoscopy was performed 1 month after the procedure. There was no sign of restenosis or collapse with a small scar tissue that did not require any further intervention (Figure 2D). As of last contact, 7 months post-coblation, he was doing well with no breathing issues.

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Figure 2.

(A) Bronchoscopic view prior to coblation. (B) An airway-specific wand was used to ablate the tumor. (C) Bronchoscopic view immediately postprocedure. (D) Bronchoscopic view 1 month following coblation.

Case 2

A 53-year-old woman who complained of shortness of breath for 1 month was admitted. Initial bronchoscopy revealed a solid, smooth, globular tumor in the lower trachea that almost completely occluded the tracheal lumen (Figure 3A). Interventional bronchoscopy was performed, and the tumor was ablated as previously described (Figure 3B and C). A minimal amount of bleeding occurred during this process. Postoperative pathology confirmed a tracheal leiomyoma. The patient had normal breathing after the procedure and was discharged the following day. She remained symptom-free 4 months following the procedure, and the follow-up bronchoscopy demonstrated that the lower trachea remained patent with normal overlying mucosa (Figure 3D).

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Figure 3.

(A) Bronchoscopic view prior to coblation. (B) Bronchoscopic view during the procedure. (C) Bronchoscopic view immediately postprocedure. (D) Bronchoscopic view 4 months following coblation.

Case 3

A 50-year-old man who complained of progressive dyspnea and hemoptysis for 1 month was admitted. Three years ago, he was diagnosed with squamous cell carcinoma of the right lower lobe and underwent surgical resection. Bronchoscopy revealed tumor recurrence in the lower part of the trachea and carina (Figure 4A). An airway-specific wand was used to ablate the tumor (Figure 4B), and airway stenosis was quickly relieved (Figure 4C). A moderate amount of bleeding occurred, and the concurrent suction in the device decreased blood and tissue displacement into the distal airway. No obvious hypoxemia occurred during the process. The residual tumor basement was finally ablated by argon plasma coagulation (Figure 4D). The patient’s dyspnea was relieved immediately after operation. He was discharged on postoperative day 3 and continued to receive chemotherapy treatment at a local hospital.

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Figure 4.

(A) Bronchoscopic view prior to coblation. (B) Bronchoscopic view during the procedure. (C) Bronchoscopic view following coblation demonstrating grade I airway stenosis. (D) Bronchoscopic view after argon plasma coagulation.

Discussion

In this article, we described a novel use of radiofrequency coblation technology, in which a new type of tracheal-specific wand was used.

In this study, all 3 patients experienced objective clinical improvement after the intervention. No severe procedure-related or short-term complications occurred. The coblation process for both benign and malignant tracheal tumors appeared to be safe and satisfactory. In addition, compared with other ablation techniques, the cobaltion technique has the following advantages: First, for benign tracheal tumors such as case 1 and case 2, the relatively low temperature of coblation minimizes injury to normal tracheal mucosa. This may decrease the risk of granulation tissue or scar formation. ² For malignant lesions or tumors with potential infectious risks such as papilloma, the coblation process have the same laser-like cutting action without going through aerosolization, which may reduce the chance of tumor planting and the spread of the virus. ⁴ Second, the coblation process for tracheal tumors proved to be time efficient. For hard benign tracheal tumors such as schwannoma in case 1, sometimes they are difficult to cutoff when an electrical knife or snare is used. Continuous electrical cutting can aggravate damage to basal tissue. Coblation, by comparison, provides a more efficient ablation process. For malignant tracheal tumors with a rich blood supply such as case 3, it improves hemostatic potential, and the concurrent suction in the device decreases blood and tissue displacement into the distal airway, which also helps to save operation time. Third, the relatively low temperature and use of continuous saline irrigation by the console device minimizes the risk of airway fires. Furthermore, the risk of hypoxia from maintaining a low fractional inspiratory oxygen level (Fio ₂) to prevent fire is avoided.

The major limitations of this case report must be illustrated. First, this is an initial attempt to evaluate the use of coablation in the treatment of tracheal tumors and only 3 cases were included. Second, due to the rarity of primary tracheal tumors, the 2 cases of benign tumors in this report are not representative of benign lesions typically seen in the trachea. Third, patients were still needed to be followed due to the limitation of follow-up period.

Conclusion

Although an initial attempt, our findings suggest the possibility of usage of coablation in the treatment of tracheal tumors. More studies that are larger and have a longer follow-up are needed to further evaluate the use of this technique.