Placement of a subdural evacuating port system for management of iatrogenic hyperacute subdural hemorrhage following intracranial monitor placement

A 22-year-old man was admitted with a severe traumatic brain injury developed a hyperacute subdural hematoma (SDH) following attempted brain tissue oxygen monitor placement. This patient was successfully treated by placement of a subdural evacuation portal system (SEPS). The patient presented to a Level I trauma center after a severe bike versus auto accident. On admission, he was found to have a Glasgow Coma Scale (GCS) score of 3. The patient had small areas of intraparechymal hemorrhage as well as suspicion for diffuse axonal injury in the midbrain. Based on the patient’s GCS score, neurological monitoring was indicated as a part of his intensive care unit treatment, however a SDH occurred during an attempted placement of a brain tissue oxygen monitor. This iatrogenic hyperacute SDH after burr hole monitoring device placement was treated with a SEPS drain. The SEPS drain has been shown to provide complete and/or temporary decompression of liquefied SDH. To our knowledge, this is the first report of using the SEPS to treat iatrogenic SDH associated with an intracranial monitoring device. This technique should be added to the armament of treatment options for a neurosurgeon to treat or temporize a hyperacute SDH with increased intracranial pressure in specific patients.     

Cervical osteotomy in ankylosing spondylitis: evaluation of new developments

Objectives: Cervical osteotomy can be performed on patients with cervical kyphosis due to ankylosing spondylitis. This study reviews the role of two new developments in cervical osteotomy surgery: internal fixation and transcranial electrical stimulated motor evoked potential monitoring (TES-MEP). Methods: From 1999 to 2004, 16 patients underwent a C7-osteotomy with internal fixation. In 11 patients, cervical osteotomy was performed in a sitting position with halo-cast immobilization (group S), five patients underwent surgery in prone position with Mayfield clamp fixation (group P). In group P, longer fusion towards T4-T6 could be obtained that created a more stable fixation. Therefore, post-operative immobilization protocol of group P was simplified from halo-cast to cervical orthosis. Results: Consolidation was obtained in all patients without loss of correction. Post-operative chin-brow to vertical angle measured 5° (range 0–15). TES-MEP was successfully performed during all surgical procedures. In total, nine neurological events were registered. Additional surgical intervention resulted in recovery of amplitudes in six of nine events. In two patients spontaneous recovery took place. One patient showed no recovery of amplitudes despite surgical intervention and a partial C6 spinal cord lesion occurred. Conclusion: We conclude that C7 osteotomy with internal fixation has been shown to be a reliable and stable technique. When surgery is performed the in prone position, distal fixation can be optimally obtained allowing post-operative treatment by cervical orthosis instead of a halo-cast. TES-MEP monitoring has been shown to be a reliable neuromonitoring technique with high clinical relevancy during cervical osteotomy because it allows timely intervention before occurrence of permanent cord damage in a large proportion of the patients.     

Intraoperative neuromonitoring in thoracoscopic excision of brachial plexus schwannoma

Mediastinal schwannoma arising from brachial plexus are rare, but their surgical treatment could be challenging with a minimally invasive approach, given their position. Furthermore, their proximity to brachial plexus nerve fibres raises the risk for postoperative upper limb deficits. A 72-year-old man presented mediastinal schwannoma arising from the T1 nerve root. Complete surgical excision was achieved via video-assisted thoracic surgery with the aid of intraoperative neuromonitoring, and no postoperative neurological deficit developed after the intervention. Using intraoperative neuromonitoring, radical minimally invasive surgical treatment can be safely achieved for mediastinal schwannoma arising from brachial plexus.     

Neuromonitoring of the Recurrent Nerve: Validation and Merits

Summary BACKGROUND: Neuromonitoring is being advocated in thyroid surgery to aid in the identification of the recurrent laryngeal nerve and to predict the postoperative vocal cord function. Here we documented and analyzed electromyographic responses to investigate the reliability of transligamental neuromonitoring under surgical conditions. METHODS: In a prospective study on 12 nerves at risk, the electromyogram was recorded with the computerized Neurosign100^® system to (i) estimate the nerve conduction velocity, (ii) to compare the magnitude of the response after vagal and recurrent nerve stimulation and (iii) to document the effects of a nicotinic acetylcholine receptor antagonist. RESULTS: The nerve conduction velocity was estimated at 45 m/s. Half-maximum and near-maximum responses were elicited by 0.17 and 1 mA, respectively. The magnitude of the electrical field response (but not the conduction velocity) depended on the extent of neuromuscular blockade thus identifying a possible confounding intraoperative variable. The field response after contralateral stimulation was about 10-fold smaller than after ipsilateral stimulation. Sole use of the neuromonitoring electrode allowed for identification of the recurrent nerve in 85 % of the trials. CONCLUSIONS: The electrophysiological and pharmacological criteria prove that neuromonitoring reliably measures the electrical response of the inner laryngeal muscles to nerve stimulation. There are, however, many variables (including electrode placement, depth of anaesthesia, extent of neuromuscular blockade) that have to be taken into account. These preclude a quantitative interpretation under surgical conditions. Thus, neuromonitoring only provides qualitative information on nerve function. A review of the literature shows that this conclusion is supported by the statistical analysis of sensitivity, specificity, positive and negative predictive value for postoperative palsy; this may, in part, also be due to the fact that the recording electrode registers the field response which is only a surrogate parameter for vocal cord mobility.     

Neuromonitoring Is Not a Standard Procedure in Thyroid Surgery

Summary BACKGROUND: The main concern with postoperative results is the integrity of the voice. As there is no causal therapy for recurrent nerve paralysis, close attention has to be paid to the preservation of the laryngeal motor nerve. Neuromonitoring (NM) is a new technique for identifying the nerve in its anatomical position, but it has failed to lower the postoperative complication rate. METHODS: The data from the literature were compared. Many studies showed a rapid decrease in palsy rates by general nerve preparation, but the outcome was still influenced by various factors such as underlying disease and surgical radicality. Only one study did not show any difference in outcome with or without nerve identification. RESULTS: Even though there is an unequal composition of data sources, it is highly suggestive that surgical development that has focussed attention on nerve preservation has led to an improvement in postoperative outcome. In general, palsy rates with nerve preparation are below 1%. The same improvement is reported with the use of neuromonitoring. It seems that these effects are similar to those obtained by nerve preparation alone. Moreover, intra- and postoperative nerve function does not always correlate. No clear-cut advantage in the results achieved with NM can be stated. CONCLUSIONS: Besides the fact that considerable basic research has been done using NM, the data concerning improvement of nerve palsy rates do not necessitate its general use in routine thyroid surgery. Subtle operative technique and visualization of the structure are still mandatory. NM might help shorten the learning curve in identification exercises.     

Factors associated with adverse neurodevelopmental outcomes in infants with congenital heart disease

OBJECTIVE: To review reported neurodevelopmental outcome data for patients with congenital heart disease, identify risk factors for adverse neurodevelopmental sequelae and summarize potential neuromonitoring strategies that have been described. METHODS: A Medline search was performed utilizing combinations of the keywords congenital heart, cardiac, neurologic, neurodevelopment, neuromonitoring, quality of life, and outcome. All prospective and longitudinal follow-up studies of patients with congenital heart disease were included. Additionally, studies that examined neuroimaging, neuromonitoring, and clinical factors in relation to outcome were examined. Case reports and editorials were excluded. Additional references were retrieved from selected articles if the abstract described an evaluation of neurodevelopmental outcomes and/or predictors of outcome in patients with congenital heart disease. RESULTS: Overall, patients with CHD have increased rates of neurodevelopmental impairments, although intelligence appears to be in the normal range. Preoperative risk stratification, intraoperative techniques, postoperative care, and neuromonitoring strategies may all contribute to ultimate long-term neurodevelopmental outcomes in patients with CHD postsurgical repair. CONCLUSIONS: As advances in the medical and surgical management improves survival in patients with CHD, increasing knowledge about neurodevelopmental outcomes and the factors that affect them will provide for strategies to optimize long-term outcome in this high-risk population.     

Stimulating catheter as a tool to evaluate peripheral nerve function during hip rotationplasty

OBJECTIVE: Stimulating catheters have been introduced into clinical practice to confirm perineural localization of the catheters. The muscular twitch induced over the catheter may be used to evaluate nerve function intraoperatively. Therefore, the function of the sciatic nerve was evaluated during major cancer surgery of the femur. CASE REPORT: A 7-year-old boy (29 kg) was scheduled for hip rotationplasty for resection of an osteosarcoma of the left femur under general anesthesia and postoperative pain therapy with an epidural stimulating catheter. In hip rotationplasty the femur is resected, the lower limb and foot are rotated 180 degrees and the tibia plateau is attached to the pelvic acetabulum to form a new hip joint. During preparation of the left thigh and the sciatic nerve, motor responses to stimulation of the catheter were preserved, but the stimulation threshold increased. After vascular anastomosis the foot remained cold, therefore ropivacaine was applied epidurally and subsequently a warming of the foot was observed. At the end of the operation, the patient was free of pain, a good capillary pulse of the leg was observed, and the patient was able to move the foot and toes of the rotated leg. CONCLUSIONS: The use of epidural stimulating catheters as a tool to monitor nerve function is a novel and simple procedure to monitor nerve function intraoperatively and to enable good postoperative pain control.     

Unusual cause of recurrent arterial embolism: floating thrombus in the aortic arch surgically removed under hypothermic cardiocirculatory arrest

A 46-year-old fully active, asymptomatic man suffered two episodes of major peripheral arterial embolism within 2 months. Heart disease was ruled out by appropriate investigations. Further diagnostic evaluation (angiography, CAT scan) revealed the extremely rare finding of a “floating mass” in the transverse aortic arch suspected to be the source of embolization. This mass was successfully removed using the technique of hypothermic cardiocirculatory arrest. The histological diagnosis was an aged intraluminal thrombus and moderate atherosclerosis of the thoracic aorta. For prevention of recurrent arterial embolism in cases without an initially apparent cause and site of origin, a thorough diagnostic, and in a given patient, an aggressive surgical approach for the elimination of the embolic source are advocated.