Neodymium:yttrium-aluminium-garnet laser for excision of pulmonary nodules: an institutional review

Lung Metastatectomy: Can Laser-Assisted Surgery Make a Difference?

BACKGROUND

Resection of lung metastases with curative intention in selected patients is associated with prolonged survival. Laser-assisted resection of lung metastases results in complete resection of a high number of lung metastases, while preserving lung parenchyma. However, data concerning laser lung resections are scarce and contradictory. The aim of this study was to conduct a systematic review to evaluate the utility of laser-assisted pulmonary metastasectomy.

METHODS

An electronic search in MEDLINE (via PubMed), complemented by manual searches in article references, was conducted to identify eligible studies.

RESULTS

Fourteen studies with a total of 1196 patients were included in this metanalysis. Laser-assisted surgery (LAS) for lung metastases is a safe procedure with a postoperative morbidity up to 24.2% and almost zero mortality. LAS resulted in the resection of a high number of lung metastases with reduction of the lung parenchyma loss in comparison with conventional resection methods. Survival was similar between LAS and conventional resections.

CONCLUSION

LAS allows radical lung-parenchyma saving resection of a high number of lung metastases with similar survival to conventional methods.

Comparison of the local effects of a 600-μm bare fibre at high laser power on lung parenchyma: Nd:YAG laser 1320 vs. 1064 nm

Lung metastases are often resected non-anatomically with a laser using a diode-pumped Nd:YAG laser at a wavelength of 1320 nm with a laser output of up to 60 W. Usually the removal of lesions is carried out in contact mode by means of a bare fibre. We compared the local effects of an Nd:YAG laser at a wavelength of 1064 nm with those at a wavelength of 1320 nm using a 600-μm bare fibre in contact mode in an experimental model. The investigations were carried out on porcine lungs freshly withdrawn at the abattoir. The 600-μm laser fibre was fixed vertically in contact with the lung surface on a fibre holder. The fibre holder was connected to a feeding device that advances the laser fibre at constant speeds (5, 10 or 20 mm/s). In each case, two laser powers were examined: 20 and 60 W. The lung lesions produced by the laser fibre were excised for histological examination. After haematoxylin-eosin staining, the depth of the vaporisation and coagulation zones (in μm) from the laser cuts was measured. For each setting, an average value was calculated. The individual groups were compared for significance using a non-parametric Mann-Whitney U test (p < 0.05). At a low speed of the bare fibre of 5 mm/s and a laser output of 20 W, the average depth of the vaporisation zone was 858 ± 3.3 μm (λ = 1064 nm) compared to 766.0 ± 7.5 μm (λ = 1320 nm) (p < 0.01). Upon faster movement (20 mm/s), the extension of the vaporisation zone decreased to 320.3 ± 7.1 μm (λ = 1064 nm). The depth of the vaporisation zone increased significantly at 60 W, both at λ = 1064 and 1320 nm with 1517.0 ± 1.7 μm and 1414.0 ± 4.9 μm, respectively. The extent of the coagulation zone was significantly smaller at 20 W and the low speed of 5 mm/s, namely, 200.4 ± 3.7 μm (λ = 1064 nm) and 224.1 ± 2.8 μm (1320-nm laser). Upon faster movement of the laser fibre at the same output, the extent of the coagulation zone decreased in both groups. At a laser power of 60 W, the extent of the coagulation zone was significantly less with the 1064-nm laser (110.3 ± 2.4 μm) than with the 1320-nm laser (324.8 ± 1.9 μm; p < 0.001). When the laser fibre moves more rapidly, the extent of the coagulation zone decreases further. The Nd:YAG laser with a wavelength of 1320 nm still has the optimal ratio of cutting and coagulation capacity on the resection surface. With the 1064-nm Nd:YAG laser, a higher cutting capacity is associated with a decrease of the coagulation capacity.

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

INTRODUCTION

Neodymium:yttrium aluminum garnet (Nd:YAG) laser resection is one of the most established interventional pulmonology techniques for immediate debulking of malignant central airway obstruction (CAO). The major aim of this study was to investigate the complication rate and identify clinical risk factors for complications in patients with advanced lung cancer.

METHODS

In the period from January 2006 to January 2011, data sufficient for analysis were identified in 464 patients. Nd:YAG laser resection due to malignant CAO was performed in all patients. The procedure was carried out in general anesthesia. Complications after laser resection were defined as severe hypoxemia, global respiratory failure, arrhythmia requiring treatment, hemoptysis, pneumothorax, pneumomediastinum, pulmonary edema, tracheoesophageal fistulae, and death. Risk factors were defined as acute myocardial infarction within 6 months before treatment, hypertension, chronic arrhythmia, chronic obstructive pulmonary disease (COPD), stabilized cardiomyopathy, previous external beam radiotherapy, previous chemotherapy, and previous interventional pulmonology treatment.

RESULTS

There was 76.1% male and 23.9% female patients in the study, 76.5% were current smokers, 17.2% former smokers, and 6.3% of nonsmokers. The majority of patients had squamous cell lung cancer (70%), small cell lung cancer was identified in 18.3%, adenocarcinoma in 3.4%, and metastases from lung primary in 8.2%. The overall complication rate was 8.4%. Statistically significant risk factors were age (P = 0.001), current smoking status (P = 0.012), arterial hypertension (P < 0.0001), chronic arrhythmia (P = 0.034), COPD (P < 0.0001), and stabilized cardiomyopathy (P < 0.0001). Independent clinical risk factors were age over 60 years (P = 0.026), arterial hypertension (P < 0.0001), and COPD (P < 0.0001).

CONCLUSION

Closer monitoring of patients with identified risk factors is advisable prior and immediately after laser resection. In order to avoid or minimize complications, special attention should be directed toward patients who are current smokers, over 60 years of age, with arterial hypertension or COPD.