Tension Pneumocephalus Secondary to Positive Pressure Ventilation Following Endoscopic Endonasal Skull Base Surgery: Three-Year Follow-Up After Implementation of an Institutional Protocol.

BACKGROUND: Tension pneumocephalus (PMC) is a rare and feared complication following the endonasal endoscopic approach (EEA) to skull base procedures. This is a neurosurgical emergency that requires urgent decompression to avoid catastrophic neurologic damage or death. An avoidable cause is the application of positive pressure ventilation (PPV) in EEA patients for postoperative hypoxia. Our institution implemented a hospital-wide protocol in response to this to identify and manage at-risk patients; this paper aims to identify if this protocol was effective in lowering the rates of tension PMC secondary to PPV. RESULTS: In the 3 years following the implementation of the protocol, 110 patients underwent EEAs, from which 1 case of tension PMC (found to be not secondary to PPV) was identified. This is compared with 2 cases of tension PMC secondary to PPV over the preceding 5 years, out of 406 EEA patients. This constitutes a quantifiable reduction in PPV-related tension PMC in both standard and extended approach EEAs, signifying the effective uptake of the protocol. CONCLUSIONS: We found no cases of tension PMC after PPV following EEA skull base surgery in our institution since the implementation of an institution-wide guideline. This underscores the utility of our simple and cost-effective preventative protocol in reducing the overall rates of tension PMC following the inadvertent postoperative application of PPV. Further research is needed to study the comparative risks and benefits of PPV in the post-EEA patient and thus inform future iterations of the protocol.

Minimizing pneumocephalus during deep brain stimulation surgery.

BACKGROUND: Deep brain stimulation (DBS) surgery is an effective treatment for movement disorders. Introduction of intracranial air following dura opening in DBS surgery can result in targeting inaccuracy and suboptimal outcomes. We develop and evaluate a simple method to minimize pneumocephalus during DBS surgery. METHODS: A retrospective analysis of prospectively collected data was performed on patients undergoing DBS surgery at our institution from 2014 to 2022. A total of 172 leads placed in 89 patients undergoing awake or asleep DBS surgery were analyzed. Pneumocephalus volume was compared between leads placed with PMT and leads placed with standard dural opening. (112 PMT vs. 60 OPEN). Immediate post-operative high-resolution CT scans were obtained for all leads placed, from which pneumocephalus volume was determined through a semi-automated protocol with ITK-SNAP software. Awake surgery was conducted with the head positioned at 15-30°, asleep surgery was conducted at 0°. RESULTS: PMT reduced pneumocephalus from 11.2 cm3±9.2 to 0.8 cm3±1.8 (P<0.0001) in the first hemisphere and from 7.6 cm3 ± 8.4 to 0.43 cm3 ± 0.9 (P<0.0001) in the second hemisphere. No differences in adverse events were noted between PMT and control cases. Lower rates of post-operative headache were observed in PMT group. CONCLUSION: We present and validate a simple yet efficacious technique to reduce pneumocephalus during DBS surgery.

Semisitting position for cerebello-pontine angle surgery: Analysis of complications and how to avoid it.

OBJECTIVE: To analyze the primary complications related to semisitting position in patients undergoing cerebelo-pontine angle surgery. METHODS: Retrospective data analysis from patients undergoing elective tumoral cerebelo-pontine angle surgery in a semisitting position. The incidence, severity, occurrence moment, treatment, duration, and outcomes of venous air embolism (VAE), pneumocephalus, postural hypotension, and other complications were recorded. Neurointensive care unit (NICU), length of stay (LOS), hospital LOS, and modified Rankin scale scores were calculated six months after surgery. RESULTS: Fifty patients were operated on. Eleven (22%) presented VAE (mean duration 8±4.5min): five (10%) during tumor resection, and four (8%) during dural opening. Ten (20%) were resolved by covering the surgical bed, air bubbles aspiration, jugular compression, and one (2%) tilted to a steep Trendelenburg position. One (2%) had intraoperative hemodynamic instability. The only variable associated with VAE was meningioma at histopathology OR=4.58, p=0.001. NICU was higher in patients with VAE (5.5±1.06 vs. 1.9±0.20 days, p=0.01). There were no differences in the Rankin scale. All patients presented postoperative pneumocephalus with a good level of consciousness, except one (2%) who required evacuation. Seven patients (14%) showed postural hypotension, three (6%) after positioning, and one (2%) after developing a VAE; all were reversed with usual vasoactive drugs. No other position-related complications or mortality were registered in this series. CONCLUSIONS: The semisitting position is a safe option with the knowledge, prevention, detection, and early solution of all the possible complications. The development of VAE rarely implies hemodynamic instability or greater disability after surgery. Postoperative pneumocephalus is very common and rarely requires evacuation. Excellent cooperation between anesthesia, nursing, neurophysiology, and neurosurgery teams is essential to manage complications.

The semi-sitting position in patients with indwelling CSF shunts: perioperative management and avoidance of complications.

OBJECTIVE: Posterior fossa or midline tumors are often associated with hydrocephalus and primary tumor removal with or without perioperative placement of an external ventricular drain (EVD) is commonly accepted as first-line treatment. Shunting prior to posterior fossa surgery (PFS) is mostly reserved for symptomatic cases or special circumstances. There are limited data regarding the anticipated risk for symptomatic pneumocephalus and the perioperative management using the semi-sitting position (SSP) in such a scenario. Here, we therefore assessed the safety of performing PFS in a consecutive series of patients over a period of 15 years to allow the elaboration of recommendations for perioperative management. METHODS: According to specific inclusion and exclusion criteria a total of 13 patients who underwent 17 operations was identified. Supratentorial pneumocephalus was evaluated with semiautomatic-volumetric segmentation. The volume of pneumocephalus was evaluated according to age and ventricular size. RESULTS: Ten of the 13 patients had a programmable valve (preoperative valve setting range 6-14 cmH20; mean 7.5 cmH20) while 3 patients had non programmable valves. A variable amount of supratentorial air collection was evident in all patients postoperatively (range 3.2-331 ml; mean 122.32 ml). Positive predictors for the volume of postoperative pneumocephalus were higher age and a preoperative Evans ratio > 0.3. In our series, we encountered no cases of tension pneumocephalus necessitating an air replacement procedure as well as no obstruction, disconnection, infection or hardware malfunction of the shunt system. CONCLUSIONS: Our findings indicate that a CSF shunt in situ is not a contraindication for performing PFS in the semi-sitting position and it does not increase the pre-existing risk for postoperative tension pneumocephalus. In cases of primary shunting for hydrocephalus associated with posterior fossa tumors a programmable valve set at a medium opening pressure with a gravitational device is a valid option when PFS in the semi-sitting position is opted. In patients with an indwelling shunt diversion system special caution is indicated in order to prevent and detect overdrainage especially in not adjustable valves or shunts without antisiphon devices.

Prophylactic Antibiotics in Patients with Traumatic Pneumocephalus or Cerebrospinal Fluid Leak.

INTRODUCTION: Pneumocephalus and cerebrospinal fluid (CSF) leaks are uncommon after trauma, but they expose the sterile CSF to environmental pathogens and create theoretical risk of central nervous system infection (CNSI). Prophylactic antibiotics are commonly given to these patients, but there is a paucity of evidence to guide this practice. We aim to quantify the incidences of these entities and analyze the efficacy of prophylactic antibiotics in preventing CNSIs. METHODS: A retrospective cohort study was conducted using our institutional trauma registry. All patients admitted from January 2014 to July 2020 with traumatic pneumocephalus (TP) or basilar skull fracture with CSF leak (BSF-CSF) were included. ICD-9 and ICD-10 codes were used to identify CNSIs. CNSI rates among defined prophylactic antibiotic regimens, no antibiotics, and other antibiotic regimens were evaluated. ANOVA was used to analyze differences between the groups. RESULTS: 365 patients met inclusion criteria: 360 with TP; 5 with BSF-CSF. 1.1% (4/365) of patients developed CNSI, all with isolated traumatic pneumocephalus. 1.4% of patients (1/72) without antibiotics; 1.2% (3/249) receiving IV antibiotics outside of a defined regimen; and 1.1% (1/88) on a designated prophylactic regimen developed CNSIs. ANOVA indicated the incidence of CNSI was not significantly different among patients who received antibiotics or not, regardless of the regimen (p-value 0.958). CONCLUSION: TP and BSF-CSF are rare diagnoses among trauma patients. The rate of CNSI is marginal and antibiotics do not appear to confer a protective advantage. A larger trial is needed to elucidate the true effect of antibiotics on preventing CNSIs in patients with these uncommon diagnoses.

How to avoid pneumocephalus in deep brain stimulation surgery? Analysis of potential risk factors in a series of 100 consecutive patients.

BACKGROUND: Accuracy of lead placement is the key to success in deep brain stimulation (DBS). Precise anatomic stereotactic planning usually is based on stable perioperative anatomy. Pneumocephalus due to intraoperative CSF loss is a common procedure-related phenomenon which could lead to brain shift and targeting inaccuracy. The aim of this study was to evaluate potential risk factors of pneumocephalus in DBS surgery. METHODS: We performed a retrospective single-center analysis in patients undergoing bilateral DBS. We quantified the amount of pneumocephalus by postoperative CT scans and corrected the data for accompanying brain atrophy by an MRI-based score. Automated computerized segmentation algorithms from a dedicated software were used. As potential risk factors, we evaluated the impact of trephination size, the number of electrode tracks, length of surgery, intraoperative blood pressure, and brain atrophy. RESULTS: We included 100 consecutive patients that underwent awake DBS with intraoperative neurophysiological testing. Systolic and mean arterial blood pressure showed a substantial impact with an inverse correlation, indicating that lower blood pressure is associated with higher volume of pneumocephalus. Furthermore, the length of surgery was clearly correlated to pneumocephalus. CONCLUSION: Our analysis identifies intraoperative systolic and mean arterial blood pressure as important risk factors for pneumocephalus in awake stereotactic surgery.

Techniques for pneumocephalus and brain shift reduction in DBS surgery: a review of the literature.

Deep brain stimulation has become an established therapeutic choice to manage the symptoms of medically refractory Parkinson's disease. Its efficacy is highly dependent on the accuracy of electrodes' positioning in the correct anatomical target. During DBS procedure, the opening of the dura mater induces the displacement of neural structures. This effect mainly depends on the loss of the physiological negative intracranial pressure, air inflow, and loss of cerebrospinal fluid. Several studies concentrated on correcting surgical techniques for DBS electrodes' positioning in order to reduce pneumocephalus which may result in therapeutic failure. The authors focused in particular on reducing the brain air window and maintaining the pressure gradient between intra- and extracranial compartments. A significant reduction of pneumocephalus and brain shift was obtained by excluding the opening of the subarachnoid space, by covering the dura mater opening with tissue sealant and by reducing the intracranial pressure in general anesthesia. Smaller burr hole diameters were not statistically relevant for reducing air inflow and displacement of anatomical targets. The review of the literature showed that conserving a physiological intra-extracranial pressure gradient plays a fundamental role in avoiding pneumocephalus and consequent displacement of brain structures, which improves surgical accuracy and DBS long-term results.

Endoscopic repair of spontaneous skull base defects decreases the incidence rate of intracranial complications.

BACKGROUND: Spontaneous skull base defects can result in life-threatening intracranial complications (ICCs), including meningitis and pneumocephalus. Endoscopic skull base reconstruction (ESBR) has traditionally been the treatment of choice, but its impact upon ICCs is not known. In this study, we aimed to describe the incidence rate of preoperative ICCs in patients with spontaneous skull base defects, risk factors associated with ICC development, and the impact of surgical repair on the incidence rate of ICCs. METHODS: A retrospective review was performed of all spontaneous skull base defects undergoing ESBR from 2005 to 2019 at 2 academic tertiary care medical centers. The incidence rate of ICCs and the demographics information and risk factors were collected. RESULTS: In 222 spontaneous skull base defects, preoperative ICCs occurred in 46 subjects (20.7%) with an incidence rate of 22.7 per 100 person-years. Factors significantly associated with preoperative ICCs included symptom duration, reduced body mass index (BMI), resolved cerebrospinal fluid rhinorrhea, and location in the frontal or lateral sphenoid sinuses. Endoscopic repair was successful in 97.2% of subjects and the postoperative ICC incidence rate was significantly reduced at 0.8 per 100 person-years (p < 0.001). CONCLUSION: Spontaneous skull base defects pose significant risk for life-threatening ICCs. Our findings reveal significantly elevated odds of ICC development associated with resolved CSF rhinorrhea, lower BMI, longer duration of symptoms, and defect location. Endoscopic repair is highly successful with low morbidity and significantly reduces the incidence rate of intracranial complications.

A prospective randomized clinical trial to evaluate the impact of intraoperative ventilation with high oxygen content on the extent of postoperative pneumocephalus in patients undergoing craniotomies.

Purpose of the article: To determine whether intraoperative ventilation with pure oxygen during the last stage of surgery reduces the occurrence and volume of postoperative pneumocephalus when compared to conventional air/oxygen mixture in patients undergoing craniotomy. MATERIAL AND METHODS: prospective randomized single-blinded study to compare the rate of occurrence and volume of postoperative pneumocephalus in patients undergoing craniotomy receiving intraoperative ventilation with pure oxygen (Group B) versus a conventional air/oxygen 1:1 mixture (Group A) during the last stage of surgery. This trial was registered in ClinicalTrials.gov #NCT02722928, protocol number 2015H0032. RESULTS: One hundred patients were randomized into group 'A' and group 'B'. Seventy patients were included in the final analysis with 39 patients allocated in group 'A' and 31 patients in group 'B'. Median and IQR were used for postoperative penumocephalus volume. Group A: 9.65 [3.61-23.20]; Group B: 7.06 [2.70-20.1]. Our study showed no prophylactic effect on postoperative pneumocephalus volume when using mechanical ventilation with higher oxygen concentrations than the standard FiO2 during the last stage of surgery in patients undergoing craniotomy (p = .47). No statistical difference was found in SICU LOS between groups (median 1,380 min [group A] versus 1,524 min [group B]; p = .18). CONCLUSION: The use of intraoperative mechanical ventilation with pure oxygen was not associated with a prophylactic effect on the occurrence and extent of postoperative pneumocephalus in our patient setting. Published literature describing the extent of postoperative pneumocephalus is limited or highly variable among institutions.

Asleep Deep Brain Stimulation Reduces Incidence of Intracranial Air during Electrode Implantation.

BACKGROUND: Asleep deep brain stimulation (aDBS) implantation replaces microelectrode recording for image-guided implantation, shortening the operative time and reducing cerebrospinal fluid egress. This may decrease pneumocephalus, thus decreasing brain shift during implantation. OBJECTIVE: To compare the incidence and volume of pneumocephalus during awake (wkDBS) and aDBS procedures. METHODS: A retrospective review of bilateral DBS cases performed at Oregon Health & Science University from 2009 to 2017 was undertaken. Postimplantation imaging was reviewed to determine the presence and volume of intracranial air and measure cortical brain shift. RESULTS: Among 371 patients, pneumocephalus was noted in 66% of wkDBS and 15.6% of aDBS. The average volume of air was significantly higher in wkDBS than aDBS (8.0 vs. 1.8 mL). Volumes of air greater than 7 mL, which have previously been linked to brain shift, occurred significantly more frequently in wkDBS than aDBS (34 vs 5.6%). wkDBS resulted in significantly larger cortical brain shifts (5.8 vs. 1.2 mm). CONCLUSIONS: We show that aDBS reduces the incidence of intracranial air, larger air volumes, and cortical brain shift. Large volumes of intracranial air have been correlated to shifting of brain structures during DBS procedures, a variable that could impact accuracy of electrode placement.

Efficacy of Arachnoid-Plasty on Chronic Subdural Hematoma Following Surgical Clipping of Unruptured Intracranial Aneurysms.

BACKGROUND: We aimed to elucidate the effects of arachnoid plasty (ARP) on chronic subdural hematoma (CSDH) occurrence following clipping surgery. METHODS: In total 217 patients (ARP, n = 97; non-ARP, n = 120) who had undergone unruptured intracranial aneurysm (UIA) surgical clipping via the pterional approach were retrospectively assessed. Predisposing factors for CSDH development following the surgery were investigated. Thickness and volume of the subdural fluid collection (SDFC) were measured to determine whether ARP affects postoperative SDFC. RESULTS: The occurrence of postoperative CSDH was higher in patients without ARP compared to those with ARP (12.5 vs. 3.1%; P = 0.01). In multivariate analyses, having an SDFC volume ≥15 mL on postoperative day (POD) 8, (odds ratio [OR] = 15.113; range = 3.159-72.290), and male sex (OR = 4.274; range = 1.291-14.148) were identified as independent predictive factors. Having had ARP (OR = 0.228; range = 0.056-0.927) was, as an independent variable, negatively correlated with the occurrence of CSDH (P < 0.05). Moreover, SDFC volume ≥15 ml on POD 8 was significantly less common in the ARP group compared with the non-ARP group (P = 0.03). CONCLUSION: Patients who underwent ARPs developed fewer CSDHs following UIA clipping surgery. The factors that predicted the development of CSDH included male sex, SDFC volume on POD 8, and ARP. In addition, the ARP patients had lower SDFC volumes (<15 mL). These findings suggested that ARP reduced the incidence of CSDHs after surgical clippings in patients with unruptured aneurysms.

Nasopharyngeal airway to prevent tension pneumocephalus after open resection of anterior skull base tumors.

We conducted a retrospective study to assess the efficacy of using a nasopharyngeal airway in lieu of a tracheotomy or prolonged intubation for the diversion of airflow to prevent tension pneumocephalus after an open resection of anterior skull base tumors. Our study population was made up of 120 patients-74 males and 46 females, aged 12 to 84 years (mean: 48.7)-who had undergone an anterior skull base resection with documented nasopharyngeal airway placement from 1996 through 2009. Our main outcome measure was the presence of tension pneumocephalus while controlling for the placement of a lumbar drain, the development of a cerebrospinal fluid (CSF) leak, and the type of reconstruction. All patients had been extubated on the day of surgery, and their nasopharyngeal airway had remained in place for 3 days. No documented complications of nasopharyngeal airway placement (e.g., nasal septum pressure necrosis or the displacement of tubes) had been documented. Tension pneumocephalus occurred in 3 patients (2.5%). A total of 33 patients (27.5%) received a lumbar drain, 14 (11.7%) experienced a CSF leak, and 5 (4.2%) had both. There was a statistically significant difference in the rate of tension pneumocephalus between patients who did and did not receive a lumbar drain placement (p = 0.02), between those who did and did not experience a CSF leak (p = 0.04), and between those who did and did not meet both criteria (p = 0.004). We conclude that resection of anterior skull base tumors does not necessitate a prophylactic tracheotomy or prolonged intubation and that the use of a nasopharyngeal airway to divert airflow is well tolerated and highly successful. Lumbar drainage, the development of a CSF leak, or both may increase the risk of tension pneumocephalus.

Simple solution for preventing cerebrospinal fluid loss and brain shift during multitrack deep brain stimulation surgery in the semisupine position: polyethylene glycol hydrogel dural sealant capping: rapid communication.

This study evaluated preliminary findings on the efficacy of polyethylene glycol (PEG) hydrogel dural sealant capping for the prevention of cerebrospinal fluid (CSF) leakage and pneumocephalus during deep brain stimulation (DBS) surgery in the semisupine position. Group A consisted of 5 patients who underwent bilateral subthalamic nucleus (STN)-DBS surgery without PEG hydrogel dural sealant capping. Group B consisted of 5 patients who underwent bilateral STN-DBS surgery with PEG hydrogel dural sealant capping. The immediate postoperative intracranial air volume was measured in all patients and compared between the 2 groups using the Welch test. Adverse effects were also examined in both groups. The intracranial air volume in Group A was 32.3 ± 12.3 ml (range 19.1-42.5 ml), whereas that in Group B was 1.3 ± 1.5 ml (range 0.0-3.5 ml), showing a significant difference (p < 0.005). No hemorrhage or venous air embolisms were observed in either group. The effect of brain shift was discriminated by STN recordings in Group B. These preliminary findings indicate that PEG hydrogel dural sealant capping may reduce adverse effects related to CSF leakage and brain shift during DBS surgery.

Air travel after intracranial surgery: a survey of advice given to patients by consultant neurosurgeons in the UK.

OBJECTIVE: Air travel following intracranial surgery is considered to be associated with a risk of tension pneumocephalus. However, the likelihood of it is currently undetermined in the literature. We decided to establish if there was any consensus amongst UK neurosurgeons with regard to advice given to patients. METHODS: A questionnaire was approved by the Scientific Meeting Committee of the Society of British Neurological Surgeons (SBNS) and then distributed to all current practicing Consultant Neurosurgeons in the UK via e-mail. RESULTS: 61/66 responders advised patients not to fly for a period of time postoperatively. 35/61 of these neurosurgeons advised a fixed post-operative timescale against flying irrespective of the nature of surgery. The remaining 26/61 advised patients with complex surgical procedures against flying for a longer period. However, the timescales advised by different surgeons in both categories varied between <2 weeks and >8 weeks. Pneumocephalus was the main concern for air travel (42/61) and 17/61 precluded flying due to concerns regarding complications away from home. 3/61 were concerned with deep vein thrombosis. CT scans were obtained prior to discharge by 11/61 of these neurosurgeons. 5/66 neurosurgeons did not advise patients against flying and their advice was independent of the type of surgery. Only one of these 5 neurosurgeons obtained a pre-discharge CT scan. CONCLUSION: Clinical practice varies widely due to a lack of clear evidence, standards or guidelines. Should the SBNS be producing national guidelines to standardise the advice given to patients?

Anterior and anterolateral resection for skull base malignancies: techniques and complication avoidance.

Combined anterior cranial base resection is the mainstay of therapy for skull base malignancies. Improvements in surgical techniques and reconstruction have led to a reduction in morbidity and overall better survival rates. Meticulous attention to dural and skull base reconstruction is essential for reducing the major complications, including cerebrospinal fluid leak and pneumocephalus. Complications can be devastating, but timely effective management can limit the severity.

Cerebrospinal fluid volume replacement following large endoscopic anterior cranial base resection.

BACKGROUND: Large endoscopic skull-base resections often result in extensive postoperative pneumocephalus secondary to copious evacuation of cerebrospinal fluid (CSF) during the procedures. Replacing CSF lost during craniotomy with saline is a common technique in neurosurgery, but is difficult after extensive transnasal resection of the anterior cranial base because direct transnasal CSF augmentation will escape until the skull base reconstruction is sealed. The present study evaluated the effectiveness of intraoperative CSF volume replacement via lumbar drains on improving postoperative outcomes. METHODS: Ten large endoscopic anterior skull-base resections (>2.5 cm) were performed from 2008 to 2011. Sellar, parasellar, and transplanum resections were excluded. Etiologies included esthesioneuroblastoma (2), squamous cell carcinoma (2), intracranial dermoid (2), adenocarcinoma (1), adenoid cystic carcinoma (1), melanoma (1), and meningioma (1). Six patients were administered preservative-free normal saline via lumbar drain during skull-base reconstruction. Data collected included volume of postoperative pneumocephalus, intravenous pain medicine requirements 24 hours after surgery, and length of hospital stay. RESULTS: Volume of pneumocephalus (4.78 cm vs 12.8 cm(3) , p = 0.04) and length of hospital stay (2.17 days vs 8.5 days, p = 0.03) were significantly decreased in the normal saline volume replacement group. Average intravenous pain medication requirements were reduced in the first 24 hours postoperatively (8 mg morphine vs 14 mg morphine, p = 0.25), but did not reach statistical significance. CONCLUSION: Evacuation of intracranial air by transthecal administration of saline during reconstruction of large anterior cranial base defects was an effective technique to decrease postoperative pneumocephalus and length of hospital stay. Further evaluation is warranted.

Head positioning and risk of pneumocephalus, air embolism, and hemorrhage during subthalamic deep brain stimulation surgery.

PURPOSE: The objective of the present study was to evaluate the risk of pneumocephalus, venous air embolism (VAE), and intracranial hemorrhage in subthalamic nucleus (STN) deep brain stimulation (DBS) patients operated in the strict supine (head and body flat) position. METHODS: This was a retrospective review of clinical records and brain imaging of patients who underwent STN DBS between January 2007 and June 2009 at the University of Kansas Medical Center. RESULTS: A total of 61 patients underwent 114 lead implantations (53 staged bilateral and 8 unilateral). No case involved a transventricular route. Intracranial air volumes ranged from 0 to 7.02 cm³ (mean 0.98 ± 1.42 cm³). Pneumocephalus volumes were highly skewed with no air present after 44 (38.6%) lead implantations, >0 to 1 cm³ in 35 (30.7%), >2 to 3 cm³ in 17 (14.9%), and >3 cm³ (average 4.97 cm³) in 9 (7.9%). There was no incidence of clinically apparent VAE or symptomatic intracranial hemorrhage. There was no association between age, degree of atrophy, sagittal angle of surgical approach, number of microelectrode runs (MERs), distance of gyrus from inner skull bone at the entry point, or surgical side and pneumocephalus. However, the majority of lead implantations (100 leads; 88%) required only one MER and there were minimal measurable distances between entered gyrus and adjacent bone. CONCLUSIONS: Our data suggest that strict supine positioning during STN DBS surgery results in minimal intracranial air and is not associated with VAE or symptomatic intracranial hemorrhage when the operative method described is used.

Fitness to fly post craniotomy--a survey of medical advice from long-haul airline carriers.

Commercial airline passengers are subject to numerous medical risks while in transit. Seventeen long-haul airline companies were questioned concerning fitness to travel and the case of a patient wishing to travel post craniotomy. Three airline companies gave satisfactory medical information, while the remaining airlines felt it was the decision of the operating surgeon rather than the airline company. A literature review shows that post operative pneumocephalus and the risk of tension pneumocephalus is the major medical concern when transporting patients post craniotomy. Evidence is contradictory with respect to the importance of this potentially life threatening problem. Postoperative 100% oxygen may improve the rate of pneumocephalus absorption. Airline companies have an unstandardised approach to unique medical problems, resulting in increased responsibility for the attending surgeon who may be ill equipped to deal with poorly researched aviation medicine.