Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal ageadjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.
Adult ; Anesthesia, General ; Anthropometry ; Brain Neoplasms ; Brain ; Child ; Cranial Nerves ; Electromyography ; Evoked Potentials, Auditory, Brain Stem ; Evoked Potentials, Motor ; Evoked Potentials, Somatosensory ; Humans ; Infratentorial Neoplasms ; Intraoperative Neurophysiological Monitoring ; Longitudinal Studies ; Monitoring, Intraoperative ; Motor Neurons ; Muscles ; Neurophysiology ; Neurosurgery ; Peripheral Nerves ; Prospective Studies

BACKGROUND/AIMS: To report the long-term survival and tumor recurrence outcomes in patients with superficial esophageal cancer (SEC) after complete non-curative endoscopic resection (ER). METHODS: We retrieved ER data for 24 patients with non-curatively resected SEC. Non-curative resection was defined as the presence of submucosal and/or lymphovascular invasion on ER pathology. Relevant clinical and tumor-specific parameters were reviewed. RESULTS: The mean age of the 24 study patients was 66.3±8.3 years. Ten patients were closely followed up without treatment, while 14 received additional treatment. During a mean follow-up of 59.0±33.2 months, the 3- and 5-year survival rates of all cases were 90.7% and 77.6%, respectively. The 5-year overall survival rates were 72.9% in the close observation group and 82.1% in the additional treatment group (p=0.958). The 5-year cumulative incidences of all cases of recurrence (25.0% vs. 43.3%, p=0.388), primary EC recurrence (10.0% vs. 16.4%, p=0.558), and metachronous EC recurrence (16.7% vs. 26.7%, p=0.667) were similar between the two groups. CONCLUSIONS: Patients with non-curatively resected SEC showed good long-term survival outcomes. Given the similar oncologic outcomes, close observation may be an option with appropriate caution taken for patients who are medically unfit to receive additional therapy.
Esophageal Neoplasms* ; Follow-Up Studies ; Humans ; Incidence ; Pathology ; Recurrence* ; Survival Rate

BACKGROUND/AIMS: Approximately 30% of esophageal cancer (EC) patients cannot complete endoscopic ultrasonography (EUS) due to malignant stricture (EUS non-traversability). This study examines clinical implications of EUS non-traversability in patients with advanced locoregional squamous EC receiving preoperative chemoradiotherapy (CRT) followed by esophagectomy. METHODS: We retrieved data on 89 consecutive patients with advanced locoregional squamous EC (stage II or III). Relevant clinical and tumor-specific parameters were reviewed retrospectively. Significant factors affecting survival was determined by Cox regression analysis. RESULTS: EUS non-traversable EC was observed in 26 of 89 patients (29.2%). Median serum albumin level (3.6 g/dL vs. 3.9 g/dL, p = 0.028), tumor length (6.0 cm vs. 4.0 cm, p = 0.002), and percentage of clinical stage III disease (65.4% vs. 38.1%, p = 0.019) were significantly different between the patients with EUS non-traversable and traversable EC, respectively. Patients with EUS non-traversable EC demonstrated a significantly lower 5-year overall survival than patients with EUS traversable EC (30.8% vs. 49.3%, p = 0.023). In multivariate analysis, weight loss ≥ 10% (p = 0.033), EUS non-traversability (p = 0.003), non-response to preoperative CRT (p = 0.002), and incompletion of esophagectomy (p = 0.002) were significant negative factors of survival. CONCLUSIONS: EUS non-traversability has significant negative prognostic implications in patients with advanced locoregional squamous EC receiving preoperative CRT followed by esophagectomy.
Carcinoma, Squamous Cell ; Chemoradiotherapy ; Constriction, Pathologic ; Endosonography* ; Esophageal Neoplasms* ; Esophagectomy ; Humans ; Multivariate Analysis ; Prognosis ; Retrospective Studies ; Serum Albumin ; Weight Loss

BACKGROUND/AIMS: Approximately 30% of esophageal cancer (EC) patients cannot complete endoscopic ultrasonography (EUS) due to malignant stricture (EUS non-traversability). This study examines clinical implications of EUS non-traversability in patients with advanced locoregional squamous EC receiving preoperative chemoradiotherapy (CRT) followed by esophagectomy. METHODS: We retrieved data on 89 consecutive patients with advanced locoregional squamous EC (stage II or III). Relevant clinical and tumor-specific parameters were reviewed retrospectively. Significant factors affecting survival was determined by Cox regression analysis. RESULTS: EUS non-traversable EC was observed in 26 of 89 patients (29.2%). Median serum albumin level (3.6 g/dL vs. 3.9 g/dL, p = 0.028), tumor length (6.0 cm vs. 4.0 cm, p = 0.002), and percentage of clinical stage III disease (65.4% vs. 38.1%, p = 0.019) were significantly different between the patients with EUS non-traversable and traversable EC, respectively. Patients with EUS non-traversable EC demonstrated a significantly lower 5-year overall survival than patients with EUS traversable EC (30.8% vs. 49.3%, p = 0.023). In multivariate analysis, weight loss ≥ 10% (p = 0.033), EUS non-traversability (p = 0.003), non-response to preoperative CRT (p = 0.002), and incompletion of esophagectomy (p = 0.002) were significant negative factors of survival. CONCLUSIONS: EUS non-traversability has significant negative prognostic implications in patients with advanced locoregional squamous EC receiving preoperative CRT followed by esophagectomy.
Carcinoma, Squamous Cell ; Chemoradiotherapy ; Constriction, Pathologic ; Endosonography* ; Esophageal Neoplasms* ; Esophagectomy ; Humans ; Multivariate Analysis ; Prognosis ; Retrospective Studies ; Serum Albumin ; Weight Loss