Endoscopic cryotherapy of lung and bronchial tumors: a systematic review

Utility and Safety of Bronchoscopic Cryotechniques-A Comprehensive Review

Cryosurgical techniques are employed for diagnostic and therapeutic bronchoscopy and serve as important tools for the management of pulmonary diseases. The diagnosis of interstitial lung disease requires multidisciplinary team discussions after a thorough assessment of history, physical exam, computed tomography, and lung-function testing. However, histological diagnosis is required in selected patients. Surgical lung biopsy has been the gold standard but this can be associated with increased morbidity and mortality. Transbronchial lung cryobiopsy is an emerging technique and multiple studies have shown that it has a high diagnostic yield with a good safety profile. There is wide procedural variability and the optimal technique for cryobiopsy is still under investigation. There is emerging data that demonstrate that cryobiopsy is safe and highly accurate in the diagnosis of thoracic malignancies. Furthermore, cryorecanalization procedures are a useful adjunct for the palliation of tumors in patients with central airway obstruction. One should keep in mind that these procedures are not free from complications and should be carried out in a specialized center by a trained and experienced bronchoscopy team. We present a review of the literature on the diagnostic and therapeutic utility of bronchoscopy-guided cryosurgical procedures and their safety profile.

Innovative Invasive Loco-Regional Techniques for the Treatment of Lung Cancer

Surgical resection is still the standard treatment for early-stage lung cancer. A multimodal treatment consisting of chemotherapy, radiotherapy and/or immunotherapy is advised for more advanced disease stages (stages IIb, III and IV). The role of surgery in these stages is limited to very specific indications. Regional treatment techniques are being introduced at a high speed because of improved technology and their possible advantages over traditional surgery. This review includes an overview of established and promising innovative invasive loco-regional techniques stratified based on the route of administration, including endobronchial, endovascular and transthoracic routes, a discussion of the results for each method, and an overview of their implementation and effectiveness.

Treatment of Pulmonary Carcinoid Tumors With Bronchoscopic Cryotherapy: A 28-Year Single-center Experience

BACKGROUND

Pulmonary carcinoids are rare tumors originating from neuroendocrine cells in the lungs. Because of their potentially infiltrative nature, surgical resection remains the treatment of choice. However, not all patients with technically resectable disease will be able to undergo surgery, primarily because of poor lung function or medical co-morbidities. Centrally located, intraluminal tumors have been reported to be amenable to bronchoscopic treatment. We specifically examined the role of cryotherapy in the treatment of bronchial carcinoid tumors.

METHODS

Sixty-three patients (52.38% female) who underwent a combined total of 243 cryotherapy procedures for treatment of bronchial carcinoid between 1992 and 2020 in our institution were included in the study. Following discussion in multidisciplinary meetings, patients were considered for first-line cryotherapy when lung resection was deemed not possible or when they had rejected surgery.

RESULTS

Cryotherapy resulted in complete remission in 21 (33.33%) patients with maximum tumor diameter less than 20 mm (mean: 11.08 mm, 95% confidence interval: 8.76-13.40), and allowed 22 (34.92%) patients with larger lesions (mean: 24.04 mm, 95% confidence interval: 18.78-29.30) to proceed with parenchymal sparing resections. Marked symptomatic relief (P<0.001) was reported by 58 (92.06%) patients. The median follow-up was 33 months (range: 0 to 243 mo). One (1.59%) patient was diagnosed with recurrence in a contralateral lobe 3 years after surgery and was treated with radiofrequency ablation.

CONCLUSIONS

In the absence of a definitive randomized controlled trial comparing bronchoscopic treatment with surgical resection, we provide evidence on the safety and efficacy of cryotherapy and encourage wider adoption of this inexpensive and minimally invasive technique for treatment of bronchial carcinoids.

The value of endobronchial cryotherapy in the management of malignant endobronchial obstruction in patients with inoperable NSCLC: a prospective analysis of clinical and survival outcomes

Background

Malignant endobronchial obstruction (MEBO) is the most debilitating complication in non-small cell lung cancer (NSCLC). The therapeutic role of cryotherapy and its impact on survival has not been well addressed. This is to clarify whether the combination of endobronchial cryotherapy (EBCT) and chemoradiotherapy (CRT) improved symptoms, respiratory functions, performance status, and survival outcomes in inoperable NSCLC with symptomatic MEBO compared to that obtained by CRT alone.

Results

A prospective cohort study included 60 cases presented to Qena University Hospital, Egypt, between December 2016 and May 2019. They were divided into two groups. Group A included 30 patients who were managed with EBCT plus CRT. Group B included 30 patients who were managed with CRT alone. The outcomes assessed were symptoms relief, respiratory function tests (RFT), performance status, and survival outcomes at baseline and 4 weeks of follow-up. Group A patients showed a highly significant improvement in symptoms (cough, dyspnea, and hemoptysis), RFT, 6MWD test, and arterial blood gases, compared to group B. The mean Karnofsky score increased from 57.33±5.67% at baseline to 60.67±6.39% post-EBCT (P=0.036); group A was significantly improved compared to group B (P=0.04). The Kaplan-Meier median survival for all patients was 9.7±0.4 months (95% CI= 8.86–10.54), and group A cases (10.77±0.44 months, 95% CI= 9.9–11.6) was significantly longer than that of group B cases (8.6±0.68 months, 95% CI= 7.3–9.97; T test = 2.631, P=0.011).

Conclusion

The use of EBCT with CRT for the management of MEBO in symptomatic patients with inoperable NSCLC is an efficient and safe procedure. EBCT improves clinical outcomes, RFT, performance status, and median survival.

Trial registration

ClinTrial.Gov registration: NCT04710459 on 4/3/2021.

Interventional Pulmonology: A Brave New World

Interventional pulmonology is a dynamic and evolving field in respiratory medicine. Advances have improved the ability to diagnose and manage diseases of the airways. A shift toward early detection of malignant disease has generated a focus on innovative diagnostic techniques. With patient populations living longer with malignant and benign diseases, the role for interventional bronchoscopy has grown. In cancer groups, novel immunotherapies have improved the prospects of clinical outcomes and reignited a focus on optimizing patient performance status to enable access to anticancer therapy. This review discusses current and emerging diagnostic modalities and therapeutic approaches available to manage airway diseases.

Magnetic aerosol drug targeting in lung cancer therapy using permanent magnet

Primary bronchial cancer accounts for almost 20% of all cancer death worldwide. One of the emerging techniques with tremendous power for lung cancer therapy is magnetic aerosol drug targeting (MADT). The use of a permanent magnet for effective drug delivery in a desired location throughout the lung requires extensive optimization, but it has not been addressed yet. In the present study, the possibility of using a permanent magnet for trapping the particles on a lung tumor is evaluated numerically in the Weibel's model from G0 to G3. The effect of different parameters is considered on the efficiency of particle deposition in a tumor located on a distant position of the lung bronchi and bronchioles. Also, the effective position of the magnetic source, tumor size, and location are the objectives for particle deposition. The results show that a limited particle deposition occurs on the lung branches in passive targeting. However, the incorporation of a permanent magnet next to the tumor enhanced the particle deposition fraction on G2 to up to 49% for the particles of 7 µm diameter. Optimizing the magnet size could also improve the particle deposition fraction by 68%. It was also shown that the utilization of MADT is essential for effective drug delivery to the tumors located on the lower wall of airway branches given the dominance of the air velocity and resultant drag force in this region. The results demonstrated the high competence and necessity of MADT as a noninvasive drug delivery method for lung cancer therapy.

Organized blood clot masquerading as endobronchial tumor: A review of management and recent advances

Central airway obstruction, a frequently encountered emergency, is usually associated with blood clots, tumors, foreign bodies or mucus plugs. Airway obstruction due to blood clots can be seen as a complication of lung malignancies, infections, bronchiectasis, arteriovenous malformations or pulmonary infarction. In patients with long standing blood clots, the thrombus gets organized and firmly adherent to the airway. The diagnosis is often misleading as these clots mimic tumors clinically and on imaging. Hemoptysis is the most common presenting symptom though many patients can be asymptomatic. Direct visualization with bronchoscopy is required to establish a diagnosis. Life-threatening respiratory impairment is an indication for emergent clot retrieval. Management of these blood clots, especially when organized, is challenging. Initial attempts at removal should include suctioning, lavage or forceps extraction. When unsuccessful, further management options include balloon catheter dislodgement, use of topical thrombolytics, rigid bronchoscopy and cryoextraction.

Cryotherapy for Barrett's Esophagus

Cryotherapy or cryoablation involves the freezing of tissues to destroy unwanted tissue or to control bleeding. Endoscopic cryotherapy has been developed for gastrointestinal application by through-the-scope noncontact delivery of compressed carbon dioxide gas or liquid nitrogen (cryospray) or contact balloon cryoablation. The mechanism of cryotherapy ablative effects includes immediate injury as well as coagulation necrosis occurring over several hours and days, unlike heat-based thermal ablation. This article reviews the basis, technique, safety, efficacy, and durability for the use of endoscopic cryotherapy in Barrett's esophagus and esophageal adenocarcinoma.

Comparison of the efficacy of four endobronchial ablation techniques in dogs

The present study aimed to evaluate the safety and efficacy of four commonly used ablation techniques, namely neodymium-doped yttrium aluminium garnet (Nd:YAG) laser therapy, argon plasma coagulation (APC), high-frequency electrocautery and CO₂ cryotherapy. The techniques were performed at various powers or impedance settings, and for various durations, on the trachea of beagle dogs. Pathological changes of the tracheal wall were assessed by bronchoscopy. The endoscopic gross appearance of lesions induced by ablation treatments was consistent with the histopathological changes. The results suggested that cryotherapy was relatively safe, whereas APC induced superficial tissue coagulative necrosis. Furthermore, Nd:YAG laser therapy was the most efficient technique and showed the greatest penetration potential. In general, tissue injury was exacerbated with extended application time, at constant power or impedance. The safest application parameters were 20 W for ≤1 sec for Nd:YAG laser therapy, 40 W for ≤3 sec for electrocautery, 40 W for ≤5 sec for APC and 100 Ω for ≤120 sec for cryotherapy. At the maximum times, these settings resulted in identical pathological changes. Healing of the lesions following ablation was achieved within 3 weeks. The Nd:YAG laser, APC, electrocautery and cryotherapy endobronchial ablation techniques differed according to their potential and limitations for application on the trachea. However, when applied at specific combinations of power or impedance and duration, they exhibited similar efficacies.

Central airway tumors: interventional bronchoscopy in diagnosis and management

The diagnosis of central airway tumors is usually challenging because of the vague presentations. Advances in visualization technology in bronchoscopy aid early detection of bronchial lesion. Cryotechnology has great impact on endobronchial lesion sampling and provides better diagnostic yield. Airway tumor involvements result in significant alteration in life quality and lead to poor life expectancy. Timely and efficiently use ablation techniques by heat or cold energy provide symptoms relief for central airway obstruction. Prostheses implantation is effective in maintaining airway patency after ablative procedure or external compression. Combined interventional bronchoscopy modalities and other adjunctive therapies have improvement in quality of life and further benefit in survival. This review aims to provide a diagnostic approach to central airway tumors and an overview of currently available techniques of interventional bronchoscopy in managing symptomatic central airway obstruction.

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.

Single-port thoracoscopic right main bronchial tumor sleeve resection and secondary carinal reconstruction

We describe herein a case of single-port thoracoscopic right main bronchial tumor sleeve resection and secondary carinal reconstruction. A 66-year-old male patient had a right main bronchial tumor longer than 12 months, who had been received endobronchial cryosurgery twice before. However, the tumor relapsed quickly. Then the patient transferred to our department. He was underwent a single-port complete thoracoscopic right main bronchial tumor sleeve resection and secondary carinal reconstruction. He recovered smoothly, without any perioperative complications. On the 5th postoperative day (POD), he was discharged in good condition.

Interventional pulmonology approaches in the diagnosis and treatment of early stage non small cell lung cancer

Lung cancer management is complex and requires a multi-disciplinary approach to provide comprehensive care. Interventional pulmonology (IP) is an evolving field that utilizes minimally invasive modalities for the initial diagnosis and staging of suspected lung cancers. Endobronchial ultrasound guided sampling of mediastinal lymph nodes for staging and detection of driver mutations is instrumental for prognosis and treatment of early and later stage lung cancers. Advances in navigational bronchoscopy allow for histological sampling of suspicious peripheral lesions with minimal complication rates, as well as assisting with fiducial marker placements for stereotactic radiation therapy. Furthermore, IP can also offer palliation for inoperable cancers and those with late stage diseases. As the trend towards early lung cancer detection with low dose computed tomography is developing, it is paramount for the pulmonary physician with expertise in lung nodule management, minimally invasive sampling and staging to integrate into the paradigm of multi-specialty care.

Flexible bronchoscopy with multiple modalities for foreign body removal in adults

OBJECTIVES

Aspiration of the lower airways due to foreign body is rare in adults. This study aimed to determine the outcome of patients who received flexible bronchoscopy with different modalities for foreign body removal in the lower airways.

PATIENTS AND METHODS

Between January 2003 and January 2014, 94 patients diagnosed with foreign body in the lower airways underwent flexible bronchoscopy with different modalities, which included forceps, loop, basket, knife, electromagnet, and cryotherapy. The clinical presentation, foreign body location and characteristics, and applications of flexible bronchoscopy were analyzed.

RESULTS

Forty (43%) patients had acute aspiration, which developed within one week of foreign body entry and 54 (57%) had chronic aspiration. The most common foreign bodies were teeth or bone. More patients with chronic aspiration than those with acute aspiration were referred from the out-patient clinic (48% vs. 28%), but more patients with acute aspiration were referred from the emergency room (35% vs. 6%) and intensive care unit (18% vs. 2%). Flexible bronchoscopy with different modalities was used to remove the foreign bodies (85/94, 90%). Electromagnet or cryotherapy was used in nine patients to eliminate the surrounding granulation tissue before foreign body removal. In the nine patients with failed flexible bronchoscopy, eight underwent rigid bronchoscopy instead and one had right lower lung lobectomy for lung abscess.

CONCLUSIONS

Flexible bronchoscopy with multiple modalities is effective for diagnosing and removing foreign bodies in the lower respiratory airways in adults, with a high success rate (90%) and no difference between acute and chronic aspirations.

Successful removal of endobronchial blood clots using bronchoscopic cryotherapy at bedside in the intensive care unit

Acute airway obstruction after hemoptysis occurs due to the presence of blood clots. These conditions may result in life-threatening ventilation impairment. We report a case of obstruction of the large airway by endobronchial blood clots which were removed using bronchoscopic cryotherapy at the bedside of intensive care unit. A 66-year-old female with endometrial cancer who had undergone chemotherapy, was admitted to the intensive care unit due to neutropenic fever. During mechanical ventilation, the minute ventilation dropped to inadequately low levels and chest radiography showed complete opacification of the left hemithorax. Flexible bronchoscopy revealed large blood clots obstructing the proximal left main bronchus. After unsuccessful attempts to remove the clots with bronchial lavage and forceps extraction, blood clots were removed using bronchoscopic cryotherapy. This report shows that cryotherapy via flexible bronchoscopy at the bedside in the intensive of intensive care unit is a simple and effective alternative for the removal of endobronchial blood clots.

Removal of endobronchial malignant mass by cryotherapy improved performance status to receive chemotherapy

Although malignant endobronchial mass (MEM) has poor prognosis, cryotherapy is reportedly a palliative treatment. Clinical data on postcryotherapy MEM patients in a university-affiliated hospital between 2007 and 2011 were evaluated. Survival curve with or without postcryotherapy chemotherapy and performance status (PS) improvement of these subjects were analyzed using the Kaplan-Meier method. There were 59 patients (42 males), with median age of 64 years (range, 51-76, and median performance status of 2 (interquartile range [IQR], 2-3). Postcryotherapy complications included minor bleeding (n = 12) and need for multiple procedures (n = 10), while outcomes were relief of symptoms (n = 51), improved PS (n = 45), and ability to receive chemotherapy (n = 40). The survival of patients with chemotherapy postcryotherapy was longer than that of patients without such chemotherapy (median, 534 versus 106 days; log-rank test, P = 0.007; hazard ratio, 0.25; 95% confidence interval, 0.10-0.69). The survival of patients with PS improvement postcryotherapy was longer than that of patients without PS improvement (median, 406 versus 106 days; log-rank test, P = 0.02; hazard ratio, 0.28; 95% confidence interval, 0.10-0.81). Cryotherapy is a feasible treatment for MEM. With better PS after cryotherapy, further chemotherapy becomes possible for patients to improve survival when MEM caused dyspnea and poor PS.

Endobronchial cryotherapy facilitates end-stage treatment options in patients with bronchial stenosis: A case series

In keeping with international trends, lung cancer incidence and mortality are increasing among the Irish population with many patients presenting with advanced disease that excludes the potential for curative management. Consequently palliative treatment options for this patient group are being increasingly explored with various degrees of success. Endobronchial stenosis represents a particularly challenging area of management among these patients and a number of techniques have been described without the identification of a single gold standard. We report our experience of the first time use of endobronchial cryotherapy in Ireland with reference to a case series, including an example of its use in the management of benign disease, in order to support patients with borderline lung function and enable definitive palliative treatment.

Bronchoscopic management of malignant airway obstruction

Approximately one-third of patients with lung cancer will develop airway obstruction and many cancers lead to airway obstruction through meta stases. The treatment of malignant airway obstruction is often a multimodality approach and is usually performed for palliation of symptoms in advanced lung cancer. Removal of airway obstruction is associated with improvement in symptoms, quality of life, and lung function. Patient selection should exclude patients with short life expectancy, limited symptoms, and an inability to visualize beyond the obstruction. This review outlines both the immediate and delayed bronchoscopic effect options for the removal of airway obstruction and preservation of airway patency with endobronchial stenting.

Cryoimmunotherapy with local co-administration of ex vivo generated dendritic cells and CpG-ODN immune adjuvant, elicits a specific antitumor immunity

Cryoablation is a low-invasive surgical procedure for management of malignant tumors. Tissue destruction is obtained by repeated deep freezing and thawing and results in coagulative necrosis and in apoptosis. This procedure induces the release of tumor-associated antigens and proinflammatory factors into the microenvironment. Local administration of immature dendritic cells (DCs) potentiates the immune response induced by cryoablation. To further augment the induction of long-lasting antitumor immunity, we investigated the clinical value of combining cryoimmunotherapy consisting of cryoablation and inoculation of immature DCs with administration of the immune adjuvant, CpG oligodeoxynucleotides. Injection of the murine Lewis lung carcinoma, D122-luc-5.5 that expresses the luciferase gene, results in spontaneous metastases, which can be easily monitored in vivo. The local tumor was treated by the combined treatment. The clinical outcome was assessed by monitoring tumor growth, metastasis in distant organs, overall survival, and protection from tumor recurrence. The nature of the induced T cell responses was analyzed. Combined cryoimmunotherapy results in reduced tumor growth, low metastasis and significantly prolonged survival. Moreover, this treatment induces antitumor memory that protected mice from rechallenge. The underlying suggested mechanisms are the generation of tumor-specific type 1 T cell responses, subsequent induction of cytotoxic T lymphocytes, and generation of systemic memory. Our data highlight the combined cryoimmunotherapy as a novel antitumor vaccine with promising preclinical results. Adjustment of this technique into practice will provide the therapeutic benefits of both, ablation of the primary tumor and induction of robust antitumor and antimetastatic immunity.