Artificial pneumothorax for pain relief during microwave ablation of subpleural lung tumors

Artificial Pneumothorax Using the Liver-Directed Approach and Seldinger's Technique: Technical Feasibility and Safety

Purpose This study aimed to evaluate the technical feasibility and safety of artificial pneumothorax induction for percutaneous procedures using the liver-directed approach and Seldinger's technique. Materials and methods The data of 25 consecutive patients who underwent percutaneous procedures after inducing artificial pneumothorax were reviewed retrospectively. The liver surface was punctured with an 18-gauge indwelling needle via the intercostal space in the inferior thoracic cavity under ultrasound guidance, avoiding the lung parenchyma and leaving the catheter in place. After a deep inhalation pulled the catheter tip into the pleural cavity, a hydrophilic guidewire was inserted through the catheter. Finally, a small-diameter catheter was inserted into the pleural cavity over the guidewire to induce artificial pneumothorax. Procedure time (the time from local anesthesia to completion of the procedure), technical success (successful induction of artificial pneumothorax), clinical success (successful completion of the percutaneous procedure), and complications (categorized according to the Clavien-Dindo classification) were evaluated in this study. Results The artificial pneumothorax induction was successful in all cases. Clinical success was achieved in 23 of 25 procedures (92%). No severe complications were observed. Conclusion The liver-directed approach and Seldinger's technique for inducing artificial pneumothorax was safe and feasible for avoiding lung injury.

Microwave ablation therapy assisted by artificial pneumothorax and artificial hydrothorax for lung cancer adjacent to the vital organs

Objectives

This study aimed to investigate the technical methods and safety of artificial pneumothorax and artificial hydrothorax in the treatment of lung cancer adjacent to vital organs by CT-guided microwave ablation.

Subjects and Methods

Three of the six patients were men and three were women, with a mean age of 66.0 years (range 47-78 years). There patients had primary pulmonary adenocarcinoma, one had lung metastasis from liver cancer, one had lung metastasis from colon cancer, and one had lung metastasis from bladder cancer. There were four patients with a single lesion, one with two lesions, and one with three lesions. The nine lesions had a mean diameter of 1.1 cm (range 0.4-1.9). In three patients, the lung cancer was adjacent to the heart, and in the remaining three, it was close to the superior mediastinum. Six patients were diagnosed with lung cancers or lung metastases and received radical treatment with microwave ablation (MWA) assisted by artificial pneumothorax and artificial hydrothorax in our hospital. Postoperative complications were observed and recorded; follow-up was followed to evaluate the therapeutic effect.

Results

The artificial pneumothorax and artificial hydrothorax were successfully created in all six patients. A suitable path for ablation needle insertion was also successfully established, and microwave ablation therapy was carried out. 2 patients developed pneumothorax after operation; no serious complications such as operation-related death, hemothorax, air embolism and infection occurred.Moreover, 4-6 weeks later, an enhanced CT re-examination revealed no local recurrence or metastasis, and the rate of complete ablation was 100%.

Conclusions

Microwave ablation, assisted by artificial pneumothorax, artificial hydrothorax, is a safe and effective minimally invasive method for treating lung cancer adjacent to the vital organs, and optimizing the path of the ablation needle and broadening the indications of the ablation therapy.

Microwave ablation with local pleural anesthesia for subpleural pulmonary nodules: our experience

Objectives

To explore the efficacy and safety of local pleural anesthesia (LPA) for relieving pain during microwave ablation (MWA) of pulmonary nodules in the subpleural regions.

Materials and Methods

From June 2019 to December 2021, 88 patients with 97 subpleural nodules underwent percutaneous CT-guided MWA. Patients were divided into two groups according to whether LPA was applied; 53 patients with local pleural anesthesia during MWA; and 35 patients with MWA without LPA. The differences in technical success, pre-and post- and intra-operative visual analog scale (VAS) pain scores, complications of the procedure, and local progression-free survival (LPFS) between the two groups were assessed. Thus, to evaluate the efficacy and safety of MWA combined with LPA for treating subpleural nodules.

Results

In this study, the procedures in all patients of both groups achieved technical success according to pre-operative planning. There was no statistically significant difference in the pre-operative VAS pain scores between the two groups. Intra-operative VAS scores were significantly higher in the non-LPA (NLPA) group than in the LPA group. They remained significantly higher in the NLPA group than in the LPA group during the short postoperative period. Analgesics were used more in the NLPA group than in the LPA group intra- and postoperatively, with a statistically significant difference, especially during the MWA procedures. The overall LPFS rates were 100%, 98.333%, 98.333%, and 98.333% at 1, 3, 6, and 12 months postoperatively in the LPA group and 100%, 97.297%, 94.595%, and 94.595% postoperatively in the NLPA group, respectively. Tumor recurrence occurred in one and two patients with lung adenocarcinoma in the LPA and NLPA groups. The incidence of pneumothorax was significantly higher in the NLPA group (25,714%, 9/35) than in the LPA group (15.094%, 8/53), and there were three cases of pleural effusion (blood collection) and one case of pulmonary hemorrhage in the NLPA group.

Conclusion

Percutaneous CT-guided MWA is a safe and effective treatment for subpleural pulmonary nodules. Applying a combined LPA technique can reduce the patient's pain and complications during and after the MWA. The long-term efficacy must be verified in more patients and a longer follow-up.

Efficacy and safety of artificial pneumothorax with position adjustment for CT-guided percutaneous transthoracic microwave ablation of small subpleural lung tumors

Background

To evaluate the efficacy and safety of artificial pneumothorax with position adjustment for computed tomograpy (CT)‐guided percutaneous transthoracic microwave ablation (MWA) of small subpleural lung tumors.

Methods

Fifty‐six patients with small subpleural lung tumors (< 3.0 cm) entered the study and underwent CT‐guided MWA with (group I: 24 patients with 24 tumors) or without (group II: 32 patients with 34 tumors) the support of artificial pneumothorax. Follow‐up contrast‐enhanced CT scans were reviewed. Pain VAS (visual analog scale) scores at, during, and after ablation were compared between the two groups. Technical success, technique efficacy, local tumor control and complications were compared.

Results

Creation of the artificial pneumothorax was achieved for 24/24 (100%) in group I and no complication related to the procedure was observed. Technical success of MWA was achieved for all 58 tumors. Primary efficacy of MWA was achieved in 23 of 24 tumors (95.8%) treated in group I, and 32 of 34 tumors (94.1%) treated in group II (P = 0.771). The 12‐month local tumor control was achieved in 87.5% (21/24) in group I compared with 88.2% (30/34) in group II (P = 0.833). Pain VAS scores in group I were significantly decreased after the pneumothorax induction at, during, and after ablation compared with group II (P < 0.05). There was no significant difference in MWA‐related complications (P > 0.05).

Conclusion

Artificial pneumothorax with position adjustment for CT‐guided MWA is effective and may be safely applied to small subpleural lung tumors. Artificial pneumothorax is a reliable therapy for pain relief.

Safety and efficacy of thermal ablation for subpleural lung cancers

BACKGROUND

The study was conducted to assess the safety and efficacy of thermal ablation for the treatment of subpleural lung cancer.

METHODS

Eighty-nine patients with 101 subpleural lung cancers were identified between January 2012 and July 2018 in our database and included in this study. Tumors were classified as adhering to cervical, costal, diaphragmatic, and mediastinal pleurae. Lesions were categorized based on their relationship to the pleura: close to the pleura, causing pleural indentation, and involving the pleura. The complete ablation rate, local progression-free survival, complications, and associated factors were analyzed.

RESULTS

Subpleural lung cancers included lesions located under costal (n = 69), mediastinal (n = 17), cervical (n = 8), and diaphragmatic (n = 7) pleurae. The rate of complete ablation was 87.1% and the local progression-free survival rates at 3, 6, 12, and 24 months were 86%, 77%, 75%, and 64%, respectively. Tumor size was the most important factor influencing technique efficacy (P < 0.05), with a complete ablation rate of only 55.6% in lung cancers measuring > 30 mm. There were nine (10.11%) major complications, including one chest abscess, five cases of pneumothorax, and three cases of hemothorax. The occurrence of major complications was associated with increased levels of pain within 48 hours post-procedure (P < 0.05).

CONCLUSION

Local thermal ablation is a safe and effective treatment for subpleural lung cancers. Tumor size was the most significant factor affecting technique efficacy. Post-procedure pain indicated the possibility of major complications.