Intraoperative Neuromonitoring In Surgery Research Articles

Intraoperative neuromonitoring in surgery of cervical neurogenic tumors

Objective: To investigate the application value of intraoperative motor nerve monitoring in cervical neurogenic tumor surgery. Methods: The efficacy of intraoperative neuromonitoring (IONM) was analyzed retrospectively in 18 patients, including 6 males and 12 females, aged from 15 to 74 years, treated in Affiliated Drum Tower Hospital, Medical School of Nanjing University from June 2019 to September 2022 who underwent total cystectomy of cervical neurogenic tumors under intraoperative nerve monitoring. Results: All 18 patients had complete tumor removal, including 8 patients with tumors from the vagus nerve and 10 patients with tumors from the brachial plexus nerve. Postoperative nerve functions were normal in patients with tumors from brachial plexus nerve, and incomplete vocal cord paralysis occurred in 2 patients with tumors from vagus vagus nerve. The total incidence of motor nerve injury was 11.1% (2/18). All patients were followed up for 6 to 45 months, with no tumor recurrence. Conclusion: Intraoperative neuromonitoring has significant values in surgery of cervical neurogenic tumors, which is helpful to remove completely the tumors on the basis of protecting the nerve functions to the maximum extent.

Intraoperative neuromonitoring in surgery of supratentorial brain tumors. Part 2. Assessment of sensory conductivity, impact at outcomes and method restrictions

Among methods of assessment of sensory conductivity of neuromonitoring in surgery of supratentorial tumors somatosensory evoked potential phase reversal are used most commonly to identify location of central sulcus. Method's uniqueness lies in possibility of its usage in patients with severe paresis before operation. Its sensitivity reaches 97 % but decreases with tumor location in Rolandic area.In monitoring of visual evoked potentials integrity of visual pathways are estimated, that is actually in lesions of occipital and posterior temporal lobes. Accuracy of visual evoked potentials reaches 94 %. In contrast to mapping of visual pathways method is more unbiassed because is not founded on subjective patient's feelings and can be applied in general anesthesia.Neuromonitoring's usage increases extent of eloquent tumor resection in 2 to 5 times and decreases the number of permanent neurological deficit in 2 times after surgery.Accuracy of neuromonitoring decreases in reoperations and in ischemic damage due to angiospasm. To maintain high predictive value of the method amount of monitoring muscles should be inverse proportionally to the density of subcortical pathways in area of resection.

Intraoperative neuromonitoring in surgery of supratentorial brain tumors. Part 1. Assessment of motor conductivity

Monitoring of motor evoked potentials in surgery of supratentorial tumors estimates integrity of cortical motor centers and subcortical pathways. Violation of motor evoked potentials takes place in mechanical injury or ischemia of motor neurons. Decrease of amplitude of motor evoked potentials more than 50 % is predictor of permanent neurological deficit.Cortical mapping gives a possibility to discover eloquent brain areas before their resection. To reveal motor centers activating stimulation is applied, to find out speech or sensory areas – the inhibiting one. Positive brain mapping allows to exclude technical fault in selection of stimulation threshold but it demands a wide craniotomy. Negative mapping is more widespread, gives opportunity to use tailored craniotomy that reduces surgical injury and duration of operation. One of the most valuable factors in cortical and subcortical brain mapping is the stimulation threshold. With monopolar «train» stimulation current 1 mA spreads into approximately 1 mm. The safe value of current intensity during tumor resection in eloquent areas is 3–5 mA.Monopolar stimulation demands less time for location of eloquent brain areas, it is as accurate as the bipolar mapping and more rarely leads to intraoperative seizures. Combination of monopolar stimulator with aspirator gives opportunity to continuously allocate pyramidal tract in tumor resection.

Precise Identification of the Right Inferior Laryngeal Nerve Using Intraoperative Neuromonitoring for Surgery in a Patient with Esophageal Cancer Complicated with Aberrant Right Subclavian Artery

Precise Identification of the Right Inferior Laryngeal Nerve Using Intraoperative Neuromonitoring for Surgery in a Patient with Esophageal Cancer Complicated with Aberrant Right Subclavian Artery

The Role of Intraoperative Neuromonitoring in Surgery of Lumbosacral Schwannomas: Five Years of Experience in a Single Center

Introduction Lumbosacral schwannomas are predominantly benign tumors arising from nerves within the spinal canal. Being one of the most common intradural extramedullary tumors, spinal schwannomas comprise up to 30% of such lesions. Surgery is the primary treatment modality and after total resection recurrence is rare. We present our experiences and results with patients operated on lumbosacral schwannomas with the use of intraoperative neuromonitoring with evoked potentials (SSEP, MEP, muscle EMG, cauda mapping). Materials and Methods A retrospective review of prospectively collected data from patients with a diagnosis of lumbosacral schwannomas operated at University Hospital Centre Zagreb, Croatia, from January 2009 to May 2014 was performed. We analyzed preoperative and postoperative medical records, pathological findings, radiographic studies, and clinical outcome of patients treated surgically for lumbosacral schwannomas. Surgical outcome was compared with evoked potential changes during surgery for lumbosacral schwannoma that significantly differed from baseline values. Results In the analyzed period, 26 patients were operated on for lumbosacral schwannomas at our institution. Of these were 11 male and 15 female patients. Mean age was 49.8 years. There were 4 giant and 22 nongiant schwannomas. Giant spinal schwannoma was defined as a tumor that extends over two or more vertebral levels, erodes vertebral bodies, and/or extends into the extraspinal space disrupting myofascial planes. Low back pain and radiculopathy were the most common presenting symptoms, rarely associated with urinary incontinence. Nongiant schwannomas were treated using minimal invasive unilateral approach, while giant schwannomas were treated using laminoplasty technique. In all patients, intraoperative neuromonitoring with SSEP, MEP, and spontaneous EMG was performed. Postoperatively, 21 patients fully recovered from preoperative neurological symptoms at 6-month follow-up. In 12 patients, SSEP changes occurred during surgery that differ from baseline values but had no impact on outcome. Four patients had transient neurological worsening which was in concordance with intraoperative SSEP and EMG disturbance findings. Out of 26 tumors excised, 2 were malignant schwannomas. One of the patients with the diagnosis of malignant schwannoma had to be reoperated for recurrence and died 2 years later. One patient with giant schwannoma developed an intracranial epidural hematoma postoperatively. Conclusion Intraoperative multimodality (SSEP, EMG) monitoring properly used and understood is a useful tool in lumbosacral schwannoma surgery. It assists the surgeon through the procedure as a means of intraoperative guidance allowing for completeness and safety of tumor removal and as such can influence the surgical outcome.