Lumbar drain for CSF leakage: a word of caution

A continuous lumbar drain is a frequently practiced procedure to prevent cerebrospinal fluid (CSF) infection in post-operative neurosurgical cases. However, the level of CSF drained must correspond to the intracranial pressures, where any accidental increase in lumboventricular gradient by slipping of the drainage bag below the level of the iliac crest can lead to over drainage and catastrophe. The learning point is to use automated or manual measures to monitor Intra-Cranial Pressure (ICP) and sound alarm in such an event to prevent sagging of the brain.

ChAdOx1 nCOV-19 vaccine-induced immune thrombotic thrombocytopenia and cerebral venous sinus thrombosis (CVST)

A 27-year-old fit and well man presented with intermittent headaches associated with eye floaters and vomiting. His symptoms started 48 hours after having the first dose of ChADOx1 nCOV-19 vaccine (Vaxzevria, previously AstraZeneca COVID-19 vaccine; AstraZeneca) and bloods showed raised D-dimer, low platelets and fibrinogen. CT venogram demonstrated significant cerebral venous sinus thrombosis. He was immediately started on intravenous immunoglobulins and dabigatran after liasing with haematologist. The next day, he complained of worsening headache and new homonymous hemianopia. Repeat CT of the head showed an acute parenchymal bleed with subdural extension and was given idarucizumab and high-dose steroids. He had an emergency decompressive craniotomy and external ventricular drain as his intracranial pressures were difficult to control. Despite full medical and surgical management, his intracranial pressures continued to rise and his brain injury was felt to be too devastating and was deemed unsurvivable.

Persistent Intracranial Hypertension in a Cranial Vault Remodeling Patient With Open Skull Fractures From Horse Kick

A 4-year-old female with prior cranial vault remodeling for nonsyndromic bilateral coronal craniosynostosis sustained a severe traumatic brain injury with open skull fractures from a horse kick. Her post-traumatic course was complicated by persistently elevated intracranial pressure despite neurosurgical decompressions, maximum medical therapy, and trial of multiple pressure monitoring devices. She eventually had improvement in her intracranial pressures and made a full neurologic recovery. This case highlights the potential severity of horse kick injuries, the possible etiology of persistent intracranial hypertension in cranial vault remodeling patients following traumatic brain injury, the importance of a multi-team approach in the initial evaluation and postoperative follow-up of all craniosynostosis patients, and the necessity of helmet utilization.

Incidence of Airway Complications Associated with Deep Extubation in Adults

Background: Endotracheal extubation is the most crucial step during emergence from general anesthesia. In the vast majority of cases, this is carried out when patients are awake with return of airway reflexes. Alternatively, extubations can also be accomplished while patients are deeply anesthetized, a technique known as “deep extubation”, in order to provide a “smooth” emergence from anesthesia. This smooth emergence is particularly important for procedures that require maintenance of stable levels of intraocular and intracranial pressures, such as in neurologic, ophthalmic, and head-and-neck surgery [1]. Reluctance to performing deep extubation in adults, even in appropriate circumstances, is common and likely derives both from concerns for potential respiratory complications [2] and limited research supporting its safety. It is in this context that we designed our prospective study to understand the factors that contribute to the success or failure of deep extubation in adults. Methods: In this prospective observational study, 300 patients, age ≥ 18, American Society of Anesthesiologists Physical Status (ASA PS) Classification I - III, who underwent head-and-neck and ocular surgeries. Patients’ demographic, comorbidity, airway assessment, O2 saturation, end tidal CO2 levels, time to exit OR, time to eye opening, and respiratory complications after deep extubation in the OR were analyzed. Results: Forty (13%) out of 300 patients had at least one complication in the OR, as defined by persistent coughing, desaturation SpO2 < 90% for longer than 10s, laryngospasm, stridor, bronchospasm and reintubation. When comparing the complication group to the no complication group, the patients in the complication group had significantly higher BMI (30 vs 26), lower O2 saturation pre and post extubation, and longer time from end of surgery to out of OR (p<0.05). Conclusions: The complication rate during deep extubation in adults was low and all easily reversible. And patient factors and extubation conditions may influence probability of success in deep extubation.

Evaluating the Effects of Cerebrospinal Fluid Protein Content on the Performance of Differential Pressure Valves and Antisiphon Devices Using a Novel Benchtop Shunting Model

BACKGROUND Hydrocephalus is managed by surgically implanting flow-diversion technologies such as differential pressure valves and antisiphoning devices; however, such hardware is prone to failure. Extensive research has tested them in flow-controlled settings using saline or de-aerated water, yet little has been done to validate their performance in a setting recreating physiologically relevant parameters, including intracranial pressures, cerebrospinal fluid (CSF) protein content, and body position. OBJECTIVE To more accurately chart the episodic drainage characteristics of flow-diversion technology. A gravity-driven benchtop model of flow was designed and tested continuously during weeks-long trials. METHODS Using a hydrostatic pressure gradient as the sole driving force, interval flow rates of 6 valves were examined in parallel with various fluids. Daily trials in the upright and supine positions were run with fluid output collected from distal catheters placed at alternating heights for extended intervals. RESULTS Significant variability in flow rates was observed, both within specific individual valves across different trials and among multiple valves of the same type. These intervalve and intravalve variabilities were greatest during supine trials and with increased protein. None of the valves showed evidence of overt obstruction during 30 d of exposure to CSF containing 5 g/L protein. CONCLUSION Day-to-day variability of ball-in-cone differential pressure shunt valves may increase overdrainage risk. Narrow-lumen high-resistance flow control devices as tested here under similar conditions appear to achieve more consistent flow rates, suggesting their use may be advantageous, and did not demonstrate any blockage or trend of decreasing flow over the 3 wk of chronic use.

Craniosynostosis Part I: Pathophysiology and Patient Evaluation

Craniosynostosis is the premature fusion and obliteration of one or more cranial sutures. As a result, cranial growth can only occur parallel to the involved suture(s) resulting in predictable head shape morphologies. More importantly, the restricted cranial growth can also have a deleterious effect on the growing brain with increased intracranial pressures leading to abnormal neurocognitive development, blindness, and death. Craniosynostosis can either be syndromic or non-syndromic; and therefore, patient evaluation should be performed in a multi-disciplinary team setting for comprehensive care. Physical exam focuses on head shape morphology, associated anomalies, and signs of intracranial pressure. Imaging with 3D CT is gold standard at confirming diagnosis and extent of suture involvement. Early diagnosis is key for planning optimal intervention. This review contains 14 figures, 4 tables and, 42 references. Keywords: craniosynostosis, virchow’s law, plagiocephaly, trigonocephaly, scaphocephaly, brachycephaly, Apert Syndrome, Crouzon Syndrome, Pfeiffer Syndrome, intracranial pressure

Paradoxical Contralateral Herniation Detected by Pupillometry in Acute Syndrome of the Trephined

Severe traumatic brain injury has historically been a non-survivable injury. Recent advances in neurosurgical care, however, have demonstrated that these patients not only can survive, but they also can recover functionally when they undergo appropriate cerebral decompression within hours of injury. At the present, general surgeons are deployed further forward than neurosurgeons (Role 2 compared to Role 3) and have been provided with guidelines that stipulate conditions where they may have to perform decompressive craniectomies. Unfortunately, Role 2 medical facilities do not have access to computed tomography imaging or intracranial pressure monitoring capabilities rendering the decision to proceed with craniectomy based solely on exam findings. Utilizing a case transferred from downrange to our institution, we demonstrate the utility of a small, highly portable quantitative pupillometer to obtain reliable and reproducible data about a patient’s intracranial pressures. Following the case presentation, the literature supporting quantitative pupillometry for surgical decision-making is reviewed.