Claudia Wong

Continuous intraoperative vagus nerve stimulation for monitoring of recurrent laryngeal nerve during minimally invasive esophagectomy

For squamous cell carcinoma of the esophagus, extended mediastinal lymphadenectomy especially around the bilateral recurrent laryngeal nerves (RLN) is associated with high risk of nerve injury. This does not only result in hoarseness of voice, increase the chance of pulmonary complications, but would also affect the quality of life of patients in the long term. Methods to improve safety of lymphadenectomy are desirable. Continuous intraoperative nerve monitoring (CIONM) based on a system using vagus nerve stimulation was tested. In thyroidectomy, this system has been shown to be useful. Our patient cohort was unselected, with the intent to perform bilateral RLN dissection undergoing video-assisted thoracoscopic (VATS) esophagectomy. Intermittent nerve stimulation for mapping and CIONM were employed to monitor left RLN nodal dissection, while only intermittent stimulation was used for the right RLN. CIONM has the potential to aid RLN dissection. The learning curves for the placement technique of CIONM, the threshold level and the interpretation of myographic amplitude and latency have been overcome. With the availability of nerve mapping and CIONM, more aggressive and thorough nodal dissection may be possible with less fear of RLN injury.

Predictive factors in the evaluation of treatment response to neoadjuvant chemoradiotherapy in patients with advanced esophageal squamous cell cancer

Neoadjuvant therapy before esophagectomy is evidence-based, and is a standard-of-care for locally advanced and operable esophageal cancer. However response to such treatment varies in individual patients, from no clinical response to pathological complete response. It has been consistently shown that a good pathological responses is of prognostic value, but perhaps in the expense of those who do not. It is important to identify suitable predictive factors for response, so that patients are not exposed to potentially harmful chemotherapy and/or radiotherapy without benefits. Alternative management strategies can be devised. Various clinical, radiological, serological and potential molecular markers have been studied. None has been shown to be sufficiently reliable to be used in daily practice. Certainly more understanding of the molecular basis for response to chemotherapy/radiotherapy is needed, so that patient treatment can be tailored and individualized.