Patient-related independent clinical risk factors for early complications following Nd: YAG laser resection of lung cancer

Malignant Airway Obstruction and the Use of Nd:YAG Laser: A Systematic Review on Its Efficacy and Safety

Endobronchial malignancies with significant airway obstruction can lead to multiple complications including pneumonia, and atelectasis over a period of time. Various intraluminal treatments have proven their value in palliative treatment for advanced malignancies. Nd:YAG (neodymium-doped yttrium aluminum garnet; Nd:Y3Al5O12) laser has established its role as a major palliative intervention due to its minimal side effects and improvement in quality of life by relieving local symptoms. The systematic review was conducted with the goal of elucidating the patient characteristics, pre-treatment parameters, clinical outcomes, and possible complications resulting from the use of the Nd:YAG laser. A thorough literature search for relevant studies was conducted on PubMed, Embase, and Cochrane Library from the inception of the idea to November 24, 2022. Our study included all original studies including retrospective studies and prospective trials, but excluded case reports, case series with less than 10 patients, and studies with incomplete or irrelevant data. A total of 11 studies were included in the analysis. The primary outcomes focused on the evaluation of pulmonary functional tests, postprocedural stenosis, blood gas parameters after the procedure, and survival outcomes. Improvement in clinical status, improvement in objective scale for dyspnea, and complications were the secondary outcomes. Our study shows that Nd:YAG laser treatment is an effective form of palliative treatment to provide subjective and objective improvement in patients with advanced and inoperable endobronchial malignancies. Due to the heterogeneous study populations in the studies reviewed and the presence of many limitations, more studies are still warranted to reach a definitive conclusion.

Therapeutic bronchoscopy for malignant central airway obstruction: impact on quality of life and risk-benefit analysis

PURPOSE OF REVIEW

Malignant central airway obstruction (CAO) is a common complication in cancer and confers significant symptom burden and reduction in quality of life. Multiple bronchoscopic interventions exist for malignant CAO. In this review, we discuss the role of therapeutic bronchoscopy in the management of malignant CAO, emphasizing its impact on symptom control and quality of life while balancing the risks and benefits of intervention.

RECENT FINDINGS

Significant practice variations exist among practitioners of therapeutic bronchoscopy, and limited data exist to guide real-time clinical decision-making. Recent analyses demonstrate that therapeutic bronchoscopy is effective for symptoms associated with malignant CAO with infrequent complications. These studies also show that many of the improvements in symptoms and quality of life are sustained after intervention and are associated with improved overall survival in patients with malignant CAO. Recent data have also shown that the improvement in symptoms associated with therapeutic bronchoscopy may enable more definitive cancer treatment, further improving patient outcomes.

SUMMARY

Therapeutic bronchoscopy is safe and effective at improving patient-centered outcomes in malignant CAO. Research is ongoing to better understand its optimal role in this setting, refine decision-making regarding advanced bronchoscopic interventions, and further improve patient outcomes.

Prognostic factors for survival after bronchoscopic intervention in patients with airway obstruction due to primary pulmonary malignancy

BACKGROUND

Malignant central airway obstruction (MCAO) occurs in 20-30% of patients with primary pulmonary malignancy. Although bronchoscopic intervention is widely performed to treat MCAO, little data exist on the prognosis of interventional bronchoscopy. Therefore, we evaluated the clinical outcomes and prognostic factors of bronchoscopic interventions in patients with MCAO due to primary pulmonary malignancy.

METHODS

This retrospective study was conducted at a university hospital and included 224 patients who received interventional bronchoscopy from 2004 to 2017, excluding patients with salivary gland-type tumor. A multivariable Cox proportional hazard regression analysis was used to identify independent prognostic factors associated with survival after the first bronchoscopic intervention.

RESULTS

Among 224 patients, 191 (85.3%) were males, and the median age was 63 years. The most common histological type of malignancy was squamous cell carcinoma (71.0%). Technical success was achieved in 93.7% of patients. Acute complications and procedure-related death occurred in 15.6 and 1.3% of patients, respectively. The median survival time was 7.0 months, and survival rates at one year and two years were 39.7 and 28.3%, respectively. Poor survival was associated with underlying chronic pulmonary disease, poor performance status, extended lesion, extrinsic or mixed lesion, and MCAO due to disease progression and not receiving adjuvant treatment after bronchoscopic intervention.

CONCLUSIONS

Interventional bronchoscopy could be a safe and effective procedure for patients who have MCAO due to primary pulmonary malignancy. In addition, we found several prognostic factors for poor survival after intervention, which will help clinicians determine the best candidates for bronchoscopic intervention.

Electrosurgical and Laser Therapy Tools for the Treatment of Malignant Central Airway Obstructions

Central airway obstruction (CAO) is associated with significant morbidity and increased mortality. Bronchoscopic electrosurgical and laser ablative tools have proven to be safe and effective instruments for the treatment of malignant CAO. Although therapeutic modalities such as electrocautery, argon plasma coagulation, and laser have been used for decades, additional tools including radiofrequency ablation catheters continue to be developed for the treatment of CAO. These modalities are considered safe in the hands of experienced operators, although serious complications can occur. This review describes various electrosurgical and laser therapy tools used for the treatment of malignant CAO along with the specific advantages and disadvantages of each device.

Effect of high laser output on the central bronchi and pulmonary artery

A diode-pump Nd:YAG high-power laser (wavelength 1320 nm, power 100 W) is routinely used to surgically remove lung metastases. Even pulmonary lesions in central locations are resectable via this method, yet it also carries a potential risk of damaging the larger bronchi and vessels in the vicinity. Studies investigating the safety of using high-power lasers are lacking. We therefore aimed to examine the direct effects of a 100-watt laser on the bronchi and pulmonary artery at a standard working velocity. From freshly slaughtered pigs, we isolated cylindrical specimens of the trachea, the main and lobar bronchi, and the central pulmonary artery from the both lungs. These specimens were fixed consecutively in rows behind each other on a Styrofoam surface in the laboratory. The laser's handle was clamped into a hydraulic feed unit so that the laser was focused at constant distance perpendicular to the tissue and would move at 10 mm/s over the specimens. The Nd:YAG Laser LIMAX® 120 functioned at a consistent power of 100 W during all the experiments. The lasered specimens were examined macroscopically and histologically for tissue damage. None of the trachea or bronchial walls were perforated. Compared to the pulmonary parenchyma, we observed no vaporization effects-only minor superficial coagulation (with a mean depth of 2.1 ± 0.8 mm). This finding was histologically confirmed in each specimen, which revealed mild superficial coagulation and no damage to the cartilage. In the presence of a residual peribronchial fatty tissue, the laser effect was even attenuated. The pulmonary arteries presented no lumen openings whatsoever, merely a discrete trace of coagulation. The vessel wall revealed increased vacuolization without alteration of the remaining vessel wall. In conclusion, laser resection at 100 W of the central lung areas is safe with respect to airways and blood vessels and the laser output does not need to be reduced when treating these areas.

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.

Complications Following Therapeutic Bronchoscopy for Malignant Central Airway Obstruction: Results of the AQuIRE Registry

BACKGROUND

There are significant variations in how therapeutic bronchoscopy for malignant airway obstruction is performed. Relatively few studies have compared how these approaches affect the incidence of complications.

METHODS

We used the American College of Chest Physicians (CHEST) Quality Improvement Registry, Evaluation, and Education (AQuIRE) program registry to conduct a multicenter study of patients undergoing therapeutic bronchoscopy for malignant central airway obstruction. The primary outcome was the incidence of complications. Secondary outcomes were incidence of bleeding, hypoxemia, respiratory failure, adverse events, escalation in level of care, and 30-day mortality.

RESULTS

Fifteen centers performed 1,115 procedures on 947 patients. There were significant differences among centers in the type of anesthesia (moderate vs deep or general anesthesia, P < .001), use of rigid bronchoscopy (P < .001), type of ventilation (jet vs volume cycled, P < .001), and frequency of stent use (P < .001). The overall complication rate was 3.9%, but significant variation was found among centers (range, 0.9%-11.7%; P = .002). Risk factors for complications were urgent and emergent procedures, American Society of Anesthesiologists (ASA) score > 3, redo therapeutic bronchoscopy, and moderate sedation. The 30-day mortality was 14.8%; mortality varied among centers (range, 7.7%-20.2%, P = .02). Risk factors for 30-day mortality included Zubrod score > 1, ASA score > 3, intrinsic or mixed obstruction, and stent placement.

CONCLUSIONS

Use of moderate sedation and stents varies significantly among centers. These factors are associated with increased complications and 30-day mortality, respectively.

Neodymium yttrium-aluminium-garnet laser resection significantly improves quality of life in patients with malignant central airway obstruction due to lung cancer

Neodymium yttrium-aluminium-garnet (Nd : YAG) laser resection is one of the mostly used interventional pulmonology techniques for urgent desobstruction of malignant central airway obstruction (CAO). The major aim of this trial was to evaluate potential influence of Nd : YAG laser resection on overall quality of life (QoL) in patients with central lung cancer. Patients with malignant CAO scheduled for Nd : YAG laser resection were prospectively recruited in the trial. All patients were given European Organization for Research and Treatment, Quality of Life questionnaire (EORTC QLQ-30 v.3) before the procedure and approximately 2 weeks after the treatment. There were 37 male and 10 female patients, average age 54 ± 10 years. Most common tumour type was adenocarcinoma diagnosed in 51% of patients. Majority of patients were diagnosed in stage IIIB (53.2%) and stage IV (25.5%). Most common Eastern Cooperative Oncology Group performance status was 1 (72.3%). Nd : YAG laser resection significantly improved (P<0.0001) QoL and overall health according to EORTC QLQ-30. However, in some of the questions dealing with nausea, vomiting, diarrhoea, constipation, family life, social activities and financial situation, we did not observe statistically significant improvement. Nd : YAG laser resection of malignant CAO significantly improves QoL and overall health in patients with lung cancer.