Preoperative evaluation of a patient with a mediastinal mass can be wide-ranging and vary depending on the source of the recommendations and tumor anatomy. Our study shows that pediatric patients with mediastinal masses that had malignant-appearing characteristics on preoperative imaging frequently underwent open resection compared with the thoracoscopic group, even though rate of final malignant pathology was similar. Moreover, postoperative outcomes were not significantly different between the two surgical groups.
IDRF-negative tumors are typically associated with a minimally invasive approach, although these low-risk tumors have not been shown necessarily to have improved oncologic outcomes such as rate of complete resection, recurrence, and overall survival. In our study, given equivalent postoperative outcomes on readmission, complication, and survival rates between the VATS and open surgery groups, coupled with shorter LOS in the VATS group, preoperative consideration should be weighted towards a minimally invasive approach under amenable patient conditions. Thoracoscopy has long been shown to be a safe and effective method to resect lesions in the mediastinum, has gained popularity in increasingly complex thoracoscopic procedures, and is associated with improved surgical outcomes and lowered morbidity[4, 8]. We recommend that the thoracoscopic approach should always be attempted in the absence of anatomic restrictions.
The role of preoperative imaging is decisive in diagnosis, staging and treatment planning, delineating IDRF and resectable cancers as well as guiding surgical approach. On preoperative imaging, lesions concerning for malignancy include heterogeneity with indistinct margins, calcifications, areas of necrosis, hemorrhage and contrast enhancement, as well as involving other anatomic compartments, crossing midline, or encasing and displacing important structures. Our approach to the preoperative planning of mediastinal mass resection evaluates the size of the tumor and mediastinum relative to the size of the patient and supports VATS in spite of malignant-appearing disease. Unless patient risk factors and vessel encasement do not physically allow for a thoracoscopic approach, VATS is normally the attempted modality in all cases. Our study shows that the postoperative outcomes are not significantly different between the thoracoscopic and open surgery groups, with slight improvement in the duration of hospital stay in the minimally invasive group. Therefore, thoracoscopic resection may harbor overall benefit over open resection and should be attempted whenever possible.
Limitations to this study include a small sample size and inherent retrospective nature. While we have demonstrated a variety of pediatric patients in our multicenter study with mediastinal masses and various histopathology, our review is likely under-powered to detect a significant difference in outcomes and can only show non-inferiority of the thoracoscopic approach compared with open resection. We suspect that with a larger sample size, the length of stay difference between the VATS and open surgical group would achieve statistical significance, with a significantly lower LOS days in the minimally invasive group.