Clinical feasibility and surgical benefits of video-assisted mediastinoscopic lymphadenectomy in the treatment of resectable lung cancer

Long-term follow-up of voice changes after cervical mediastinoscopy

Background

Vocal cord palsy after cervical mediastinoscopy is usually reported at less than 1%. However, its incidence might be underestimated and no follow-up studies are available. Our study aimed to evaluate the incidence of voice changes after cervical mediastinoscopy and report on long-term outcomes, including quality of life, after at least one-year follow-up.

Methods

A retrospective cohort study was performed, considering all patients who underwent cervical mediastinoscopy in our center between January 2011 and April 2016. Patients with pre-existing voice changes, voice changes only after pulmonary resection and patients who underwent neoadjuvant chemo(radio)therapy were excluded. Voice changes with full recovery within 14 days were attributed to intubation-related causes. Follow-up questionnaires, including the standardized Voice Handicap Index, were sent to patients with documented voice changes.

Results

Of 270 patients who were included for final analysis, 17 (6.3%) experienced voice changes after cervical mediastinoscopy, which persisted > 2 years in 4 patients (1.5%), causing mild to moderate disabilities in daily living. Twelve patients (out of 17, 71%) were referred for otolaryngology consultation, and paresis of the left vocal cord suggesting recurrent laryngeal nerve injury was confirmed in 10 (3.7% of our total study group). Additionally, 83% of the patients who were referred for otolaryngology consultation received voice treatment. Recovery rate after vocal exercises therapy and injection laryngoplasty was respectively 71% and 33%.

Conclusions

Voice changes after cervical mediastinoscopy is an underreported complication, with an incidence of at least 6.3% in our retrospective study, with persisting complaints in at least 1.5% of patients, leading to mild to moderate disabilities in daily living. These findings highlight the need for appropriate patient education for this underestimated complication, as well as the exploration of possible preventive measures.

Surgical mediastinal lymph node staging for non-small-cell lung carcinoma

Background

The current preferred approach for surgical mediastinal staging of non-small-cell lung carcinoma is video-assisted mediastinoscopy. An alternative technique in which lymph nodes are resected instead of biopsied is video-assisted mediastinoscopic lymphadenectomy (VAMLA) that is suggested to be superior in detecting N2 disease. Yet, evidence is conflicting and furthermore limited by sample size. The objective was to compare mediastinal staging through VAMLA and video-assisted mediastinoscopy.

Methods

A single-center cohort study was conducted. All consecutive patients that underwent surgical mediastinal staging of non-small-cell lung carcinoma by VAMLA (2011 to 2018) were compared to historic video-assisted mediastinoscopy controls (2007 to 2011). Patients with negative surgical mediastinal staging underwent subsequent anatomical resection with systematic regional lymphadenectomy. Primary outcome was the sensitivity and negative predictive value for detecting N2 disease.

Results

Two-hundred-sixty-nine video-assisted mediastinoscopic lymphadenectomies and 118 video-assisted mediastinoscopies were performed. The prevalence of N2 disease was 20% and 26% respectively in the VAMLA and video-assisted mediastinoscopy group, while the rate of unforeseen pN2 resulting from lymph node dissection during anatomical resection was 4% and 11%, respectively. Invasive staging using VAMLA demonstrated superior sensitivity of 0.82 and a negative predictive value of 0.96 when compared to video-assisted mediastinoscopy (0.62 and 0.89, respectively), offering a 64% decrease in risk of unforeseen pN2 following anatomical resection. However, VAMLA is also associated with a 75% risk increase on complications (P=0.36).

Conclusions

We conclude that performing invasive mediastinal lymph node assessment for staging of non-small-cell lung carcinoma, VAMLA should be the preferred technique with superior sensitivity and negative predictive value in detecting N2 disease. Though, VAMLA is also associated with an increased risk of complications.

Predictors and survival impact of station 4L metastasis in left non-small cell lung cancer

BACKGROUND

It remains unclear about the predictors and survival impact of station 4L metastasis in left-sided non-small cell lung cancer (NSCLC). This study aims to investigate these issues to explore the significance of station 4L lymph-node dissection (LND).

METHODS

We retrospectively enrolled 405 patients with station 4L LND, and divided them into the positive station 4L metastasis group and the negative station 4L metastasis group. The logistic regression was performed to identify the predictors of station 4L metastasis. The survival outcomes including disease-free survival (DFS) and overall survival (OS) were analyzed in pN2 patients to explore the prognostic effect of station 4L metastasis.

RESULTS

There were 48 (11.9%) patients in the positive station 4L metastasis group and 357 (88.1%) patients in the negative station 4L metastasis group. Station 5 metastasis (P = 0.008, OR 7.578, 95% CI 1.710-33.589), station 10 metastasis (P = 0.004, OR 7.133, 95% CI 1.904-26.717), and cN2 (P = 0.010, OR 5.062, 95% CI 1.473-17.392) were independent risk factors of station 4L metastasis. In pN2 patients, the positive station 4L metastasis group had inferior DFS (P = 0.019) and OS (P = 0.006) compared with the negative station 4L metastasis group, and station 4L metastasis was the independent risk factor for poor prognosis.

CONCLUSION

It is of great necessity to perform station 4L LND in left NSCLC, because station 4L metastasis is not rare and has an unfavorable prognosis.

[Video-assisted thoracic surgery : A global development]

More than 200 years ago the first attempts at thoracoscopy were made but only after its introduction 25 years ago has video-assisted thoracoscopic surgery (VATS) experienced rapid progress. Due to worldwide cooperation and international networking tremendous progress of the technique was made by thoracic surgeons on all continents developing the technique into a less invasive operating procedure on the thorax. For patients this meant improvement in the quality of life and ultimately better survival rates following lung cancer surgery. The VATS procedures are nowadays the preferred method unless the size and extent of the tumor prohibits a minimally invasive procedure. New trends in VATS are ambulatory, drainless or uniportal VATS, the latter being possible because insufflation of carbon dioxide is not necessary, allowing manipulation with multiple instruments through one small incision. The other trend is robotic-assisted thoracic surgery. The benefits of the robotics are higher degrees of freedom for movement of the instruments. The development of VATS is nowadays a global one with North America and Asian countries being the most active protagonists, but European countries also play an important role in shaping the future of minimally invasive surgery. Modern media help to further promote the technique.

Preoperative mediastinal lymph node staging for non-small cell lung cancer: 2014 update of the 2007 ESTS guidelines

Accurate preoperative staging and restaging of mediastinal lymph nodes in patients with potentially resectable non-small cell lung cancer (NSCLC) is of paramount importance. In 2007, the European Society of Thoracic Surgeons (ESTS) published an algorithm on preoperative mediastinal staging integrating imaging, endoscopic and surgical techniques. Over the last years more evidence of the different mediastinal staging technique has become available. Therefore, a revision of the ESTS guidelines was needed. In case of CT-enlarged or PET-positive mediastinal lymph nodes, tissue confirmation is indicated. Endosonography (EBUS/EUS) with fine needle aspiration is the first choice (when available) since it is minimally invasive and has a high sensitivity to rule in mediastinal nodal disease. If negative, surgical staging with nodal dissection or biopsy is indicated. Video-assisted mediastinoscopy is preferred over mediastinoscopy. The combined use of endoscopic staging and surgical staging results in the highest accuracy. When there are no enlarged lymph nodes on CT and when there is no uptake in lymph nodes on PET or PET-CT, direct surgical resection with systematic nodal dissection is indicated for tumors ≤3 cm located in the outer third of the lung. In central tumors or N1 nodes, preoperative mediastinal staging is indicated. The choice between endoscopic staging with EBUS/EUS and fine needle aspiration or video-assisted mediastinoscopy depends on local expertise to adhere to minimal requirements for staging. For tumors larger than 3 cm, preoperative mediastinal staging is advised, mainly in adenocarcinoma with high SUV uptake.

Revised ESTS guidelines for preoperative mediastinal lymph node staging for non-small-cell lung cancer

Accurate preoperative staging and restaging of mediastinal lymph nodes in patients with potentially resectable non-small-cell lung cancer (NSCLC) is of paramount importance. In 2007, the European Society of Thoracic Surgeons (ESTS) published an algorithm on preoperative mediastinal staging integrating imaging, endoscopic and surgical techniques. In 2009, the International Association for the Study of Lung Cancer (IASLC) introduced a new lymph node map. Some changes in this map have an important impact on mediastinal staging. Moreover, more evidence of the different mediastinal staging technique has become available. Therefore, a revision of the ESTS guidelines was needed. In case of computed tomography (CT)-enlarged or positron emission tomography (PET)-positive mediastinal lymph nodes, tissue confirmation is indicated. Endosonography [endobronchial ultrasonography (EBUS)/esophageal ultrasonography (EUS)] with fine-needle aspiration (FNA) is the first choice (when available), since it is minimally invasive and has a high sensitivity to rule in mediastinal nodal disease. If negative, surgical staging with nodal dissection or biopsy is indicated. Video-assisted mediastinoscopy is preferred to mediastinoscopy. The combined use of endoscopic staging and surgical staging results in the highest accuracy. When there are no enlarged lymph nodes on CT and when there is no uptake in lymph nodes on PET or PET-CT, direct surgical resection with systematic nodal dissection is indicated for tumours ≤ 3 cm located in the outer third of the lung. In central tumours or N1 nodes, preoperative mediastinal staging is indicated. The choice between endoscopic staging with EBUS/EUS and FNA or video-assisted mediastinoscopy depends on local expertise to adhere to minimal requirements for staging. For tumours >3 cm, preoperative mediastinal staging is advised, mainly in adenocarcinoma with high standardized uptake value. For restaging, invasive techniques providing histological information are advisable. Both endoscopic techniques and surgical procedures are available, but their negative predictive value is lower compared with the results obtained in baseline staging. An integrated strategy using endoscopic staging techniques to prove mediastinal nodal disease and mediastinoscopy to assess nodal response after induction therapy needs further study.

Determination of standard number, size and weight of mediastinal lymph nodes in postmortem examinations: reflection on lung cancer surgery

Background

Mediastinal lymph node dissection is an essential component of lung cancer surgery. Literature lacks established information regarding the number and size of the healthy lymph nodes. In this postmortem autopsy study, we aim to define the number, size and weight of the lymph nodes in each mediastinal lymph node station. To implement the data for the clinical practice, we analyzed the possible number of nodes to be dissected in a systematic mediastinal lymph node dissection from the right and left sides during lung cancer surgery.

Methods

Sixty-two samples obtained from cadavers who did not die from chest malignancies, extrathoracic malignancies, any kind of infections or previous hospitalization before the death were included to the study. The locations of the nodes were recorded according to the American Thoracic Society Mediastinal Lymph Node Map. The number, size and weight of the nodes were determined at each station.

Results

Median age of the cadavers was 39 years. Primary causes of death were asphyxia in 10 (16.1%) subjects, trauma in 29 (46.8%) subjects, cardiovascular problems in 10 (16.1%) subjects, and undetermined in 13 (21%) subjects. The median number of lymph nodes resected from each patient was 23 (range: 11–54). The right sided paratracheal lymph nodes (Station 2R and 4R) were more frequent, heavier and longer than left sided lymph nodes (Station 2L and 4L) at the paratrecheal region. Right sided inferior mediastinal lymph nodes were heavier and longer than the left ones; however, their availability was more often on the left.

Conclusions

The properties of mediastinal lymph nodes at particular stations are different for number, size and weight. Station 4R and 7 have the highest number of nodes followed by stations 5 and 6. We recommend removing the lymph nodes of these stations completely in lung cancer patients to rule out the possibility of micrometastatic disease. Diameter of normal lymph node may be 1 cm for the stations other than 4R and 7, but the definition of normal diameter of a lymph node at the stations 4R and 7 may be changed as 1,5 cm and 2,0 cm, respectively. Weight of the nodes may be a new subject to study and may be defined as a new modality to define a staging to be more accurate and the issue needs further investigations.

Surface layer-preserving photodynamic therapy (SPPDT) in a subcutaneous mouse model of lung cancer

BACKGROUND AND OBJECTIVES

Photodynamic therapy (PDT) may be a less invasive treatment for lung cancer. Our newly developed surface layer-preserving PDT (SPPDT) technique enables us to irradiate deep tumor while preserving the overlying tissue. The aim of this basic study was to verify that the SPPDT technique might be applied to lung cancer.

STUDY DESIGN/MATERIALS AND METHODS

PDT with talaporfin sodium was performed using a pulsed laser with different pulse dose rates (PDRs, 2.5-20.0 mJ/cm(2) /pulse) in a mouse model of subcutaneous tumor. To mimic the tracheal wall structure and a thoracic tumor in the tracheobronchus, we also made a mouse model in which a piece of swine cartilage was placed between the dermis and the tumor, and PDT was carried out 2 weeks after implantation. In both experiments, the tissue samples were collected 48 hours after PDT and evaluated microscopically.

RESULTS

SPPDT using a high-PDR laser damaged the underlying tissue but left the superficial tissue intact in the mouse subcutaneous tumor model. In SPPDT, a higher PDR produced a thicker layer of intact superficial tissue than a lower PDR, while a lower PDR produced a deeper layer of damaged tissue than a higher PDR. SPPDT was also able to preserve the superficial tissue and to damage the tumor tissue beneath the cartilage implant.

CONCLUSION

SPPDT was able to damage tumor beneath the superficial normal tissue layer, which included tracheal cartilage in the mouse model. The thickness control of SPPDT was provided by controlling laser pulse intensity. SPPDT is a new technology, whose future potential is unknown. The initial clinical application of this technology could be endoscopic treatment (e.g., palliative therapy of thoracic malignancies via bronchoscopy).