Artificial pneumothorax: a safe and simple method to relieve pain during microwave ablation of subpleural lung malignancy

Hydrodissection technique for pain relief during peri-microwave ablation in patients with subpleural non-small cell lung cancers

PURPOSE

This study aimed to assess the application value of the hydrodissection technique (HT) for pain relief during peri-microwave ablation (MWA) in patients with subpleural non-small cell lung cancers (NSCLCs).

METHODS

This retrospective study comprised 218 patients with subpleural NSCLCs who underwent computed tomography (CT)-guided percutaneous MWA. The patients were divided into two groups: HT-assisted MWA (HT group) and local pleural anesthesia (LPA)-assisted MWA (LPA group). Differences in the effective rates of pain relief during MWA, visual analog scale (VAS) scores post-MWA, complications, and complete ablative rates were assessed.

RESULTS

The HT group comprised 101 patients (62 males and 39 females; mean age, 61.93 ± 10.57 years), while the LPA group comprised 117 patients (66 males and 51 females; mean age, 62.95 ± 11.16 years). The effective rate of pain relief in the HT group (82/101 patients, 81.19%) was significantly higher than that in the LPA group (66/117 patients, 56.41%), (p < 0.0001). The VAS scores at 6, 12, 24, and 48 h post-MWA were not statistically different between the two groups. The incidence of pneumothorax (grade ≥3) was significantly lower in the HT group (11/101 patients, 10.89%) than in the LPA group (27/117, 23.07%), (p = 0.0161). The complete ablative rates at 1, 3, 6, 12, and 24 months post-MWA were comparable of two groups.

CONCLUSIONS

These results indicate that HT-assisted MWA of patients with subpleural NSCLCs could effectively provide pain relief and decrease the occurrence of pneumothorax, yielding a satisfactory local therapeutic response.

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.

Single ultrasound-guided thoracic paravertebral block with a large volume of anesthetic for microwave ablation of lung tumors

Objective

To compare single ultrasound-guided thoracic paravertebral block (TPVB) using a large volume of anesthetic with local anesthesia (LA) in computed tomography (CT)-guided pulmonary microwave ablation.

Subjects and methods

Eighty patients who underwent CT-guided microwave ablation of pulmonary tumors were randomly divided into the TPVB group and the LA group. Patients of the TPVB group were anesthetized with a single injection of a large volume (40 ml) of 0.375% ropivacaine injection at T4, and those of the LA group had local infiltration by the surgeon at the puncture site, and emergency rescue with propofol injection was administered when the patient could not tolerate pain in either group. The following variables were recorded in both groups: general conditions; volume of propofol injection for emergency rescue during ablation; visual analog scale (VAS) scores during ablation and at 0, 2, 12, and 24 h after ablation; the need to use analgesics for rescue within 24 h after ablation; number of ablations; number of punctures performed by the surgeon; patient’s movements during puncturing; and puncturing-associated complications.

Results

Compared with the TPVB group, the amount of emergency use of propofol injection was significantly more in the LA group (P < 0.05). There were no significant differences in the VAS scores recorded intraoperatively and at 0, 2, 12, and 24 h after ablation between the two groups (P > 0.05). There was a significant difference in the patient’s movements upon puncturing between the two groups (P < 0.05), but there were no significant differences in the numbers of punctures and ablations between the two groups (P > 0.05). The number of patients using analgesics within 24 h after the operation was also more in the LA group than in the TPVB group, and the difference between the two groups was statistically significant (P < 0.05).

Conclusion

Single ultrasound-guided TPVB with a large volume of anesthetic offers effective analgesia for microwave ablation of lung tumors, helping the patient cooperate with the operating surgeon to reduce injury from multiple lung punctures. Further studies are recommended to validate these findings.

Clinical practice guidelines on image-guided thermal ablation of primary and metastatic lung tumors (2022 edition)

The main contents of the Clinical Practice Guidelines on Image-Guided Thermal Ablation (IGTA) of Primary and Metastatic Lung Tumors (2022 Edition) include the following: epidemiology of primary and metastatic lung tumors; the concepts of the IGTA and common technical features; procedures, indications, contraindications, outcomes evaluation, and related complications of IGTA on primary and metastatic lung tumors; and limitations and future development.

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.

Local ablation of pulmonary malignancies abutting pleura: Evaluation of midterm local efficacy and safety

Objective

To retrospectively evaluate the efficacy and safety of local ablation treatment for adjacent pleural lung tumors.

Materials and methods

Sixty-two patients who underwent pulmonary nodule ablation at the Affiliated Cancer Hospital of Zhengzhou University were enrolled between January 2016 and December 2020. All patients were followed up with enhanced computed tomography or magnetic resonance imaging within 48 h after treatment and 2, 4, 6, 9, and 12 months after treatment. All patients were followed for at least 12 months.

Results

A total of 84 targeted tumors (62 patients) underwent 94 ablations. In the 12-month follow-up images, 69 of the 84 targeted tumors were completely ablated, 15 had incomplete ablation, and the 12-month incomplete ablation rate was 17.8% (15/84). Of the 15 incompletely ablated tumors, six had partial responses, five had stable disease, and four had progressive disease. The most common adverse event was pneumothorax, with an incidence of 54.8% (34/62). The second most common complication was pleural effusion, with an incidence rate of 41.9% (26/62). The incidence of needle-tract bleeding was 21% (13/62) and all patients were cured using hemostatic drugs. Serious complications were bronchopleural fistula in four patients (6.5%, 4/62) and needle tract metastasis in one patient. Four cases of bronchopleural fistula were found in the early stages and were cured after symptomatic treatment.

Conclusion

Local ablation is effective for the treatment of adjacent pleural lung tumors, and its operation is safe and controllable.

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.

Optimization of pleural multisite anesthetic technique during CT-guide microwave ablation of peripheral lung malignancy for improving treatment tolerance

OBJECTIVE

To assess the effect and safety of subpleural multisite anesthesia based on the area of thermal radiation during CT-guided lung malignancy microwave ablation (MWA) on the incidence of moderate or severe pain and the analgesic drug usage.

MATERIALS AND METHODS

Consecutive patients with lung malignancies were retrospectively evaluated between January 2016 and December 2019. Patients undergoing CT-guided lung malignancy MWA were either given in the method of (a) standard subpleural puncture point anesthesia between January 2016 and June 2018 and (b) subpleural multisite anesthesia based on the area of thermal radiation between July 2018 and December 2019. The relationship between local anesthesia mode and moderate or severe pain, and pain medications usage was assessed by using multivariable logistic regression models.

RESULTS

A total of 243 consecutive patients were included in the study. Moderate or severe pain occurred in 84 of 124 (67.7%) patients with subpleural puncture point anesthesia and in 20 of 119 (16.8%) patients with subpleural anesthesia in the area of thermal radiation (p=.001). The intravenous pain medication was required in 56 of 124 (45.2%) patients with subpleural puncture point anesthesia and in 9 of 119 (7.6%) patients with subpleural multisite anesthesia based on the area of thermal radiation (p=.001). Local anesthesia methods (p = 0.001), pleura-to-lesion distance (p=.02) and tumor size (p=.015) were independent risk factors for developing moderate or severe pain. There were no differences in adverse events and local tumor progression rate.

CONCLUSIONS

Subpleural multisite anesthesia based on the area of thermal radiation for peripheral lung malignancy MWA can result in lower intraprocedural pain compared with the subpleural puncture point anesthesia. Thus, a subpleural multisite anesthesia technique may be most helpful when performing MWA of peripheral malignancy in patients who are not sedated with general or intravenous anesthesia.

Safety and efficacy of microwave ablation to treat pulmonary nodules under conscious analgosedation with sufentanil: A single-center clinical experience

PURPOSE

The present study was designed to evaluate the safety and efficacy of computed tomography-guided percutaneous microwave ablation (MWA) to treat pulmonary nodules under conscious analgosedation with sufentanil.

MATERIALS AND METHODS

February to May 2021, 124 patients with 151 pulmonary nodules were enrolled in this study. The patients underwent 124 sessions of MWA. Sufentanil (0.25 μg/kg) was injected intravenously before MWA.

RESULTS

The technical success was 100% and no procedure-related deaths. The dosage of sufentanil was 16.6 ± 3.0 μg. The mean tumor diameter in the enrolled patients was 1.3 ± 0.8 cm. The intraoperative mean numerical rating scale (NRS) was 2.2 ± 1.7. Among the patients with NRS >3, seven patients had nodules adjacent to the pleura, while in ten patients, they were not adjacent. The mean systolic, diastolic blood pressure, and heart rate of patients were 139.1 ± 23.5 mmHg, 77.8 ± 12.3, and 76.1 ± 13.4 times/min, respectively, before sufentanil injection. The mean lowest systolic, lowest diastolic blood pressure, and lowest heart rate intraoperative were 132.9 ± 22.0 mmHg, 76.1 ± 12.1, and 74.0 ± 13.5 times/min. Twenty-six patients had mild adverse events including nausea (6.45%, 8/124), dizziness (2.42%, 3/124), vomiting(4.03%, 5/124), nausea and dizziness (2.42%, 3/124), nausea with vomiting and dizziness (2.42%, 3/124), urinary retention (1.61%, 2/124) and respiratory depression (0.81%, 1/124).

CONCLUSION

Sufentanil is a feasible, safe, and effective analgesic for MWA in patients with pulmonary nodules. It can be used for clinical promotion.

Artificial pneumothorax improves radiofrequency ablation of pulmonary metastases of hepatocellular carcinoma close to mediastinum

BACKGROUND

To investigate the feasibility, safety and efficacy of percutaneous radiofrequency ablation (RFA) of pulmonary metastases from hepatocellular carcinoma (HCC) contiguous with the mediastinum using the artificial pneumothorax technique.

METHOD

A total of 40 lesions in 32 patients with pulmonary metastases from HCC contiguous with the mediastinum accepted RFA treatment from August 2014 to May 2018 via the artificial pneumothorax technique. After ablation, clinical outcomes were followed up by contrast enhanced CT. Technical success, local tumor progression (LTP), intrapulmonary distant recurrence (IDR), and adverse events were evaluated. Overall survival (OS) and local tumor progression free survival (LTPFS) were recorded for each patient.

RESULTS

The tumor size was 1.4 ± 0.6 cm in diameter. RFA procedures were all successfully performed without intra-ablative complications. Technical success was noted in 100% of the patients. Five cases of LTP and 8 cases of IDR occurred following the secondary RFA for treatment. Slight pain was reported in all patients. No major complications were observed. The 1, 2, and 3-year LTPFS rates were 90.6, 81.2, and 71.8%, and the 1, 2, and 3-year OS rates were 100, 100 and 87.5%, respectively.

CONCLUSION

Artificial pneumothorax adjuvant RFA is a feasible, safe, and efficient method for treatment of pulmonary metastases from HCC contiguous with the mediastinum.

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.

A new electrospray method for targeted gene delivery

A challenge for gene therapy is absence of safe and efficient local delivery of therapeutic genetic material. An efficient and reproducible physical method of electrospray for localized and targeted gene delivery is presented. Electrospray works on the principle of coulombs repulsion, under influence of electric field the liquid carrying genetic material is dispersed into micro droplets and is accelerated towards the targeted tissue, acting as a counter electrode. The accelerated droplets penetrate the targeted cells thus facilitating the transfer of genetic material into the cell. The work described here presents the principle of electrospray for gene delivery, the basic instrument design, and the various optimized parameters to enhance gene transfer in vitro. We estimate a transfection efficiency of up to 60% was achieved. We describe an efficient gene transfer method and a potential electrospray-mediated gene transfer mechanism.