The Application of Liquid Nitrogen Spray Cryotherapy in Treatment of Bronchial Stenosis

Effect of Bronchoscopic Spray Cryotherapy and Ultra-low Temperature on Physical Properties of Metallic and Silicone Airway Stents

BACKGROUND

Bronchoscopic spray cryotherapy (SCT) is utilized in the field of interventional pulmonology for treating benign and malignant airway stenosis as a standard tool to maintain airway patency. Stent-related complications include tumor overgrowth, granulation tissue, and epithelialization. Thermal ablation can have a limited role in such scenarios due to the risk of airway fire and damage to the existing stent. SCT is a potential therapy using ultra-low temperatures that can allow stents to remain in place during treatment. However, there has been no study demonstrating the safety of SCT on the integrity and physical properties of tracheobronchial stents. We report the results of the first study demonstrating the safety of SCT utilized to treat stent-associated granulation or malignant airway disease. The aim of this study was to demonstrate the effects of SCT on the physical properties of airway stents in an ex vivo environment.

METHODS

Various types of airway stents were subjected to multiple intervals of SCT for up to 30 seconds, and then the cycle was repeated 3 times. After every cycle, we compressed the stents to 60% of their original size, and compression and expansion force data was collected immediately after, at 3-minute and 5-minute intervals, and compared with the baseline readings.

RESULTS

There was no significant change in the association between diameter and compression/expansion force, including any derangement in returning to the original diameter or any physical damage to any of the stents even after 3 prolonged SCT sessions of 30 seconds.

CONCLUSION

Our study provides the first evidence that the use of SCT in conjunction with existing silicone/metal stents is feasible and does not cause any physical damage to the stents or alters their ability to maintain the original diameter.

Malignant Central Airway Obstruction: What's New?

Malignant central airway obstruction (MCAO) is a debilitating and life-limiting complication that occurs in an unfortunately large number of individuals with advanced intrathoracic cancer. Although the management of MCAO is multimodal and interdisciplinary, the task of providing patients with prompt palliation falls increasingly on the shoulders of interventional pulmonologists. While a variety of tools and techniques are available for the management of malignant obstructive lesions, advancements and evolution in this therapeutic venue have been somewhat sluggish and limited when compared with other branches of interventional pulmonary medicine (e.g., the early diagnosis of peripheral lung nodules). Indeed, one pragmatic, albeit somewhat uncharitable, reading of this article's title might suggest a wry smile and shug of the shoulders as to imply that relatively little has changed in recent years. That said, the spectrum of interventions for MCAO continues to expand, even if at a less impressive clip. Herein, we present on MCAO and its endoscopic and nonendoscopic management-that which is old, that which is new, and that which is still on the horizon.

Clinical efficacy of argon plasma coagulation combined with cryotherapy for central airway stenosis caused by lung cancer

BACKGROUND

This study aimed to study the clinical efficacy of argon plasma coagulation plus cryotherapy for central airway stenosis caused by lung cancer.

METHODS

The clinical data of 177 patients with central airway stenosis caused by lung cancer received surgery from June, 2017 to July 2018 were retrospectively analyzed. According to different treatments, 43 patients received cryotherapy were included in the control group, while 134 patients received argon plasma coagulation plus cryotherapy were in the observation group. After propensity score matching, patients in the two groups were in a 1:1 ratio. The Karnofsky score, partial pressure of oxygen (PaO₂), arterial oxygen saturation (SaO₂), partial pressure of arterial carbon dioxide (PaCO₂) and adverse reactions in patients were analyzed one week before and after treatment. Besides, the survival rates of the two groups were compared.

RESULTS

After propensity score matching, the baseline data were not significantly different between the two groups. The post-treatment Karnofsky scores in the two groups were significantly higher than those of before treatment, and the post-treatment score of the observation group was higher than that of the control group (all P < 0.05). The post-treatment PaO₂ and SaO₂ in the observation group were both higher than those of the control group; while the PaCO₂ in the observation group was significantly lower than that of the control group (all P < 0.05). In the observation group, the levels of PaO₂ and SaO₂ were significantly higher, and the level of PaCO₂ was significantly lower after treatment than those of before treatment (all P < 0.05). The rates of completely effective and mild effective in the observation group were significantly higher than those in the control group (both P < 0.05). The incidences of bleeding, arrhythmia and fever in the observation group were significantly lower than those in the control group (all P < 0.05). The survival rate was significantly higher in the observation group (72.09%) than in the control group (51.16%).

CONCLUSIONS

Argon plasma coagulation combined with cryotherapy can significantly alleviate the central airway stenosis caused by lung cancer, reduce the incidence of adverse reactions, and improve prognosis in patients.

Outcome of spray cryotherapy plus functional endoscopic sinus surgery on management of healing in nasal polyposis

BACKGROUND

Nasal Polyposis is a benign tumor in nasal or paranasal mucosa, which confronts difficulties in management of healing after treatments with surgery. The aim of this study was to evaluate the effects of Spray Cryotherapy (SCT) on management of healing in patients with nasal polyposis who undergone functional endoscopic sinus surgery.

METHODS

In this prospective, clinical trial study, we investigated on 40 patients with nasal polyposis that had indication for functional endoscopic sinus surgery. Patients were divided randomly into two parallel group; cryotherapy (with SCT) and placebo (without SCT). Evaluation of healing after surgery was evaluated with Lund-Mackay and The Sino-nasal outcome test (SNOT-22)-22 scores.

RESULT

Postoperatively, Lund-Mackay and SNOT-22 scores were significantly decreased in both groups, however these scores were significantly lower in cryotherapy group in comparison with placebo group. Also there were no reported serious side effects in both groups.

CONCLUSION

In this paper, we concluded that usage of SCT is an effective and safe method on management of healing and develops recovery rates in patients with nasal polyposis undergoing functional endoscopic sinus surgery.

Current status of spray cryotherapy for airway disease

The use of liquid nitrogen to treat skin and mucosal lesions is well understood in the dermatologic and gastrointestinal literature. Direct spray cryotherapy (SCT) in the airway has shown promising results in the treatment of esophageal premalignant and even invasive lesions. In the airway, several studies have shown it to be a safe, effective treatment for both benign and malignant disease. It is easily administered in the outpatient setting and can be repeated several times without undue side effects. In this article, we review the current literature on the use of SCT for the treatment of endobronchial lesions and also describe our own institutional experience of the use of SCT in the airway. The use of proper technique and airway venting is important in mitigating the complications of barotrauma from massive expansion of nitrogen upon conversion from the liquid to gaseous state. We also review some of the basic science principals behind the use of the cryotherapy to treat lesions in different tissues. We feel that SCT is a potential area for further research at both clinical and basic science level.