Value of systematic mediastinal lymph node dissection during pulmonary metastasectomy

Area of Science:

• Thoracic Surgery
• Surgical Oncology
• Pulmonary Medicine

Background:

• Systematic mediastinal lymph node dissection is standard for bronchial carcinoma resection.
• Mediastinal lymph node dissection is not routine in pulmonary metastasectomy; only suspicious nodes are removed.
• The incidence of mediastinal lymph node metastasis in pulmonary metastases is unknown.

Purpose of the Study:

• To determine the incidence of malignant infiltration in mediastinal lymph nodes during pulmonary metastasectomy.
• To evaluate the impact of systematic mediastinal lymph node dissection in patients undergoing pulmonary metastasectomy.

Main Methods:

• Prospective study of 63 patients undergoing 71 pulmonary metastasectomies via thoracotomy.
• Inclusion criteria: no tumor progression, no extrathoracic metastases, curative intent, and no suspicious mediastinal lymph nodes on CT scan (<1 cm).
• Systematic mediastinal lymph node dissection was performed concurrently with metastasectomy.

Main Results:

• Malignant cells were found in mediastinal lymph nodes of 9 patients (14.3%).
• Additional pulmonary metastases were detected intraoperatively in 16.9% of cases.
• A trend towards improved survival was observed in patients without mediastinal lymph node involvement.

Conclusions:

• The frequency of misdiagnosed mediastinal lymph node metastases is comparable to non-small cell bronchial carcinomas.
• Systematic dissection identifies a significant number of patients with unsuspected residual disease.
• Identifying mediastinal metastases can influence adjuvant therapy decisions in selected cases.