Airway Spray Cryotherapy: Initial Outcomes From a Multiinstitutional Registry

Spray Cryotherapy for Benign Large Airway Stenosis: A Multicenter Retrospective Cohort Study of Safety and Practice Patterns

BACKGROUND

Benign airway stenosis (BAS) represents a significant burden on patients, providers, and healthcare systems. Spray cryotherapy (SCT) has been proposed as an adjunctive treatment to reduce BAS recurrence. We sought to examine safety and practice variations of the latest SCT system when used for BAS.

METHODS

We conducted a retrospective multicenter cohort study in seven academic institutions within the Interventional Pulmonary Outcomes Group. All patients who underwent at least one SCT session with a diagnosis of BAS at the time of procedure at these institutions were included. Demographics, procedure characteristics, and adverse events were captured through each center's procedural database and electronic health record.

RESULTS

A total of 102 patients underwent 165 procedures involving SCT from 2013 to 2022. The most frequent etiology of BAS was iatrogenic (n = 36, 35%). In most cases, SCT was used prior to other standard BAS interventions (n = 125; 75%). The most frequent SCT actuation time per cycle was five seconds. Pneumothorax complicated four procedures, requiring tube thoracostomy in two. Significant post-SCT hypoxemia was noted in one case, with recovery by case conclusion and no long-term effects. There were no instances of air embolism, hemodynamic compromise, or procedural or in-hospital mortality.

CONCLUSION

SCT as an adjunctive treatment for BAS was associated with a low rate of complications in this retrospective multicenter cohort study. SCT-related procedural aspects varied widely in examined cases, including actuation duration, number of actuations, and timing of actuations relative to other interventions.

[Bronchoscopic management of malignant central airway obstructions]

Up to 30% of lung cancer patients suffer from central airway obstruction, resulting in major deterioration in prognosis and quality of life. Interventional bronchoscopy combines a number of invasive techniques used during rigid bronchoscopy. It is designed to rapidly improve symptoms, primarily dyspnea. Applied according to very precise indications, this technique requires careful patient selection and needs to be incorporated into the multimodal oncological management in combination with systemic treatments, radiation therapy and surgery.

Comprehensive use of a high-frequency electric knife, balloon dilatation, and cryotherapy for tuberculous central tracheobronchial cicatricial constriction

BACKGROUND

To examine the benefits of interventional therapy for cicatricial constriction using a high-frequency electric knife, saccular dilatation, and cryotherapy.

METHODS

This case series included patients with central tracheobronchial cicatricial constriction admitted to the Department of Tuberculosis of Henan Provincial Chest Hospital from July 2018 to March 2021 and treated with bronchoscopic interventional therapies based on systemic anti-tuberculosis treatment.

RESULTS

96 patients were included, in whom 443 interventional therapies were performed. The total mid-(3 months) and long-term (12 months) effective rates were both 100%. The internal diameter of tracheobronchial stenosis increased after the operation, and the difference was statistically significant (all < 0.05). After interventional treatment, patients' symptoms of choking sensation in the chest and shortness of breath were relieved. Respiratory function was obviously improved. The ratios of hemorrhage, granulation hyperplasia, chest pain, and postoperative fever were 58.2%, 42.6%, 31.3%, and 26.7%, respectively. No focal transmission and progression of tuberculosis occurred, and no serious complications were observed.

CONCLUSION

The use of a high-frequency electric knife, saccular dilatation, and/or cryotherapy according to the pathological stage of the tracheobronchial cicatricial constriction is feasible, with good mid- and long-term curative effects and few complications.

Nonmalignant Central Airway Obstruction: Options for Challenging Cases

Benign central airway obstruction is commonly referred as nonmalignant central airway obstruction (NMCAO). This is in part related to its lack of benign nature and significant life-quality impairment in patients. It is a pathologic entity with various etiologies and therefore a wide range of therapeutic options are available. Evidence regarding the optimal management that could provide a sustained restoration of airway patency is lacking. The lack of a common pathophysiologic pathway translating into a nonspecific symptom presenting as NMCAO has complicated treatment standardization and subsequently limited solid research to favor of one approach over another one. Our intent is to describe the limited evidence of the most utilized nonsurgical treatment for NMCAO as well as some upcoming promising therapeutic options such as mitomycin C injection, microdebrider, biodegradable stents, radiotherapy, Hybrid Knife, and endoluminal spray cryotherapy. Our goal with this manuscript is to motivate other authors to venture into prospective, multicenter, open-label trials aimed to describe long-term outcomes in patients with NMCAO.

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.

Therapeutic Bronchoscopic Techniques Available to the Pulmonologist: Emerging Therapies in the Treatment of Peripheral Lung Lesions and Endobronchial Tumors

Therapeutic bronchoscopy for both endobronchial tumors and peripheral lung cancer is rapidly evolving. The expected increase in early stage lung cancer detection and significant improvement in near real-time imaging for diagnostic bronchoscopy has led to the development of bronchoscopy-delivered ablative technologies. Therapies targeting obstructing central airway tumors for palliation and as a method of local disease control, patient selection and patient-centered outcomes have been areas of ongoing research. This review focuses on patient selection when considering therapeutic bronchoscopy and new and developing technologies for endobronchial tumors and reviews the status of bronchoscopy-delivered ablative tools for peripheral lung cancers.

Bronchoscopic ablation techniques in the management of lung cancer

Central airway involvement is a common manifestation of lung cancer during the disease course. Some patients will require bronchoscopic therapeutic interventions to palliate symptoms, or less commonly to provide more definitive therapy of airway involvement. We describe an overview specifically of bronchoscopic ablative techniques that are available for use in malignant airway obstruction. Techniques that are more commonly used include bronchoscopic application of laser, electrocautery, argon plasma coagulation (APC), cryotherapy and mechanical debulking techniques. Less commonly employed are brachytherapy and photodynamic therapy. These techniques may be applied via flexible or rigid bronchoscopy depending upon the clinical scenario. The choice of technique depends on available tools and expertise, the urgency of the clinical scenario, and whether the lesion is predominately endobronchial, extrinsic compression, or a combination of both. Malignant airway obstruction is a common finding in lung cancer and there are a number of effective bronchoscopic ablative techniques that may be employed safely to palliate patients with a significant symptom burden.

Experimental study for evaluation of a low-cost spray cryotherapy system

Objective

To evaluate the feasibility and applicability of a low-cost cryotherapy system.

Methods

Experimental study with 25kg Landrace pigs submitted to a longitudinal cervico-thoraco-abdominal incision for exposure of the trachea, thorax and abdomen. The tissues were frozen by continuous spray application at different periods of time (5, 10 and 15 seconds). Spray cryotherapy was performed using a fluorinated gas (tetrafluorethane) delivered at - 47°C temperature (DermaFreeze^®, Emdutos; ANVISA registration 80409950001; price R$ 394,00). via an adapted, disposable 1.8mm cholangiography catheter (Olympus; price R$ 280,00). The specimens were resected for histopathological analysis.

Results

Thirty samples were obtained from ten different organs and divided according to spray cryotherapy application time. System activation for 5, 10 or 15 seconds led to consumption of 14g, 27g and 40g of gas respectively (average gas consumption, 2.7g/s using a 1.8mm catheter). The system comprising a spray tube and catheter proved user-friendly and effective, with constant gas dispersion and adequate tissue freezing. In spite of effective freezing, microscopy failed to reveal tissue changes. This may have reflected methodological constraints precluding evaluation at tissue damage peak time (48 hours).

Conclusion

The low-cost spray cryotherapy system proved feasible and safe.

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.

Prognosis of patients with primary malignant main stem bronchial tumors: 7,418 cases based on the SEER database

Background

The aim of this study was to identify risk factors for patients with malignant main stem bronchial tumors (MBTs) and to develop a nomogram for predicting prognosis in those patients using data from the Surveillance, Epidemiology, and End Results (SEER) database.

Method

A process was used for case screening from the SEER database. The effect of prognostic factors on survival was evaluated using the Kaplan–Meier method and log-rank test, a competing risk model, and the Cox proportional hazards regression model. A nomogram was established for predicting 1-, 3-, and 5-year overall survival (OS) in patients with MBTs.

Results

A total of 7,418 cases were included in this study. Age, gender, pathologic grade, histologic type, tumor size, involvement of lymph nodes, tumor extension, chemotherapy, and surgery were identified as independent risk factors by univariate and multivariate analyses. A nomogram was established based on the results of the Cox model, which was validated by a C-index of 0.672 (95% CI, 0.664–0.680), and a group of calibration plots.

Conclusion

Age, gender, pathologic grade, histologic type, tumor size, involvement of lymph nodes, tumor extension, chemotherapy, and surgery were independent risk factors for OS of patients with MBTs. A nomogram was formulated to predict 1-, 3-, and 5-year OS in patients with MBTs based on individual clinical characteristics.

Hemodynamic Instability Following Airway Spray Cryotherapy

BACKGROUND

Spray cryotherapy (SCT) of airway lesions is used to effectively palliate respiratory symptoms related to airway obstruction, but significant intraoperative hemodynamic complications have been noted. We reviewed the experience at a single institution using SCT for the treatment of obstructive airway tumors.

METHODS

A retrospective review of a single institution experience with intraoperative and postoperative hemodynamic complications associated with SCT was performed. Descriptive statistics were performed.

RESULTS

Between June 2009 and April 2010, 34 treatment sessions were performed on 28 patients. Median age was 60 years (range, 15-88 years). Tumor characteristics were as follows: 13 primary lung cancers (43%), 11 pulmonary metastases (50%), 1 direct extension of an esophageal cancer (3%), and 2 benign pulmonary lesions (7%). Twenty-one tumors (75%) were distal to the carina; 14 (50%) were >95% occlusive. Median procedure length was 78 minutes (range, 15-176 minutes). Eleven sessions (31%) led to severe hypotension and/or bradycardia, with 2 patients requiring cardiopulmonary resuscitation. One patient died intraoperatively after cardiac arrest; a second patient was stable intraoperatively but died within 24 hours of SCT. Four patients required reintubation and short-term mechanical ventilation.

CONCLUSIONS

Unpredictable life-threatening hemodynamic instability can follow endobronchial SCT. We propose that the most likely cause is pulmonary venous gaseous emboli entering the right heart, the coronary arteries, and the systemic circulation. Although SCT may offer advantages over airway laser therapy (such as no risk of fire and rapid hemostasis), further study is needed to delineate the relative likelihood of therapeutic benefit versus catastrophic complications.

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

OBJECTIVE

Spray cryotherapy (SCT), the application of liquid nitrogen in a noncontact form, has been demonstrated to have efficacy in treating various types of pathologic lesions of the airway when used as an adjunct with bronchoscopy. The purpose of the study was to evaluate the results of the use of bronchoscopic SCT on the airway in a single institution.

METHODS

We performed a retrospective review of data collected on all patients who underwent SCT to re-establish or improve airway patency in an 11-month period. Patients were classified based on the nature of their disease into benign or malignant. Demographic data, change in luminal patency, and clinical outcomes were recorded. The percent of stenosis was divided into grades according to the following classification: 1, ≤25%; 2, 26% to 50%; 3, 51% to 75%; and 4, ≥76%. We defined successful completion of treatment as obtaining a final patency of grade 1.

RESULTS

Twenty-two patients met inclusion criteria, with 45.5% (10 patients) having benign stenosis and 54.5% (12 patients) malignant. At initial bronchoscopic evaluation, the median grade of stenosis was 4 for malignant disease and 3.5 for benign disease. The median final posttreatment grade of stenosis was 2 for malignant disease and 1 for benign. The median improvement in grade of stenosis after treatment was 2 for both malignant and benign causes (Wilcoxon test, P = 0.92). Final patency of grade 1 was achieved in 42% of malignant stenosis and 80% of benign. Overall, 86.4% of patients had an improvement in grade of stenosis after treatment. The rate of morbidity was 4.5% (1/22) of all patients.

CONCLUSIONS

The median change in grade after treatment was 2 grades of improvement for both the benign and malignant groups. These results provide evidence that the use of SCT is equally efficacious for both types of stenosis with an expectation of overall improvement in luminal patency, offering a safe and effective method of achieving airway patency in a minimally invasive fashion. This study contributes to the small but growing body of literature supporting the use of SCT in benign and malignant disease.

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.

Techniques of endoscopic airway tumor treatment

Interventional bronchoscopy has a predominant role in the management of both early and advanced-stage airway tumors. Given the very poor prognosis of lung cancer, there is a need for new tools to improve early detection and bronchoscopic treatment of endo-bronchial precancerous lesions. In more advanced stages, interventional bronchoscopy plays an important role, as nearly a third of lung cancers lead to proximal airway obstruction. This will cause great discomfort or even life-threatening symptoms related to local extension, such as dyspnea, post-obstructive pneumonia, and hemoptysis. Surgery for very locally advanced disease is only effective for a limited number of patients and the effects of conventional antitumor therapies, like radiation therapy or chemotherapy, are inconstant and are too delayed in a palliative context. In this review, we aim to provide pulmonologists with an exhaustive technical overview of (I) the bronchoscopic management of benign endobronchial lesions; (II) the bronchoscopic management of malignant tumors, including the curative treatment of localized lesions and palliative management of malignant proximal airway stenosis; and (III) descriptions of the emerging endoscopic techniques used to treat peripheral lung tumors.

Integration of interventional bronchoscopy in the management of lung cancer

Tracheal or bronchial proximal stenoses occur as complications in 20-30% of lung cancers, resulting in a dramatic alteration in quality of life and poor prognosis. Bronchoscopic management of these obstructions is based on what are known as "thermal" techniques for intraluminal stenosis and/or placement of tracheal or bronchial prostheses for extrinsic compressions, leading to rapid symptom palliation in the vast majority of patients. This invasive treatment should only be used in cases of symptomatic obstructions and in the presence of viable bronchial tree and downstream parenchyma. This review aims to clarify 1) the available methods for assessing the characteristics of stenoses before treatment, 2) the various techniques available including their preferred indications, outcomes and complications, and 3) the integration of interventional bronchoscopy in the multidisciplinary management of proximal bronchial cancers and its synergistic effects with the other specific treatments (surgery, radiotherapy or chemotherapy).

Spray cryotherapy (SCT): institutional evolution of techniques and clinical practice from early experience in the treatment of malignant airway disease

BACKGROUND

Spray cryotherapy (SCT) was initially developed for gastroenterology (GI) endoscopic use in the esophagus. In some institutions where a device has been utilized by GI, transition to use in the airways by pulmonologists and thoracic surgeons occurred. Significant differences exist, however, in the techniques for safely using SCT in the airways.

METHODS

We describe the early experience at Walter Reed National Military Medical Center from 2011 to 2013 using SCT in patients with malignant airway disease and the evolution of our current techniques and clinical practice patterns for SCT use in patients. In November 2013 enrollment began in a multi-institutional prospective SCT registry in which we are still enrolling and will be reported on separately.

RESULTS

Twenty-seven patients that underwent 80 procedures (2.96 procedures/patient). The average age was 63 years with a range of 20 to 87 years old. The average Eastern Cooperative Oncology Group (ECOG) status was 1.26. All malignancies were advanced stage disease. All procedures were performed in the central airways. Other modalities were used in combination with SCT in 31 (39%) of procedures. Additionally 45 of the 80 (56%) procedures were performed in proximity to a silicone, hybrid, or metal stent. Three complications occurred out of the 80 procedures. All three were transient hypoxia that limited continued SCT treatments. These patients were all discharged from the bronchoscopy recovery room to their pre-surgical state.

CONCLUSIONS

SCT can be safely used for treatment of malignant airway tumor (MAT) in the airways. Understanding passive venting of the nitrogen gas produced as the liquid nitrogen changes to gas is important for safe use of the device. Complications can be minimized by adopting strict protocols to maximize passive venting and to allow for adequate oxygenation in between sprays.

From electrocautery, balloon dilatation, neodymium-doped:yttrium-aluminum-garnet (Nd:YAG) laser to argon plasma coagulation and cryotherapy

Over the past decade, there has been significant advancement in the development/application of therapeutics in thoracic diseases. Ablation methods using heat or cold energy in the airway is safe and effective for treating complex airway disorders including malignant and non-malignant central airway obstruction (CAO) without limiting the impact of future definitive therapy. Timely and efficient use of endobronchial ablative therapies combined with mechanical debridement or stent placement results in immediate relief of dyspnea for CAO. Therapeutic modalities reviewed in this article including electrocautery, balloon dilation (BD), neodymium-doped:yttrium-aluminum-garnet (Nd:YAG) laser, argon plasma coagulation (APC), and cryotherapy are often combined to achieve the desired results. This review aims to provide a clinically oriented review of these technologies in the modern era of interventional pulmonology (IP).