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.

Backup Frontal Drainage System for Urgent Tension Pneumocephalus Management After Chronic Subdural Hematoma Surgery: A Retrospective Cohort Study.

OBJECTIVE: To describe a simple variation of burr hole craniostomy for the management of chronic subdural hematoma (CSDH) that uses a frontal drainage system to facilitate timely decompression in the event of tension pneumocephalus and spares the need for additional surgery. METHODS: We conducted a retrospective analysis of 20 patients with CSDH who underwent burr hole craniostomy and 20 patients who underwent the same procedure alongside the placement of a 5 Fr neonatal feeding tube as a backup drainage for the anterior craniostomy. Depending on the situation, the secondary drain stayed for a maximum of 72 hours to be opened and used in emergency settings for drainage, aspiration, or as a 1-way valve with a water seal. RESULTS: The outcomes of 20 patients who underwent this procedure and 20 controls are described. One patient from each group presented tension pneumocephalus. One was promptly resolved by opening the backup drain under a water seal to evacuate pneumocephalus and the other patient had to undergo a reopening of the craniostomy. CONCLUSIONS: The described variation of burr hole craniostomy represents a low-cost and easy-to-implement technique that can be used for emergency decompression of tension pneumocephalus. It also has the potential to reduce reoperation rates and CSDH recurrence. Prospective controlled research is needed to validate this approach further.

Preventing Shift from Pneumocephalus During Deep Brain Stimulation Surgery: Don't Give Up the 'Fork in the Brain'.

Clinical vignette: We present the case of a patient who developed intra-operative pneumocephalus during left globus pallidus internus deep brain stimulation (DBS) placement for Parkinson's disease (PD). Microelectrode recording (MER) revealed that we were anterior and lateral to the intended target. Clinical dilemma: Clinically, we suspected brain shift from pneumocephalus. Removal of the guide-tube for readjustment of the brain target would have resulted in the introduction of movement resulting from brain shift and from displacement from the planned trajectory. Clinical solution: We elected to leave the guide-tube cannula in place and to pass the final DBS lead into a channel that was located posterior-medially from the center microelectrode pass. Gap in knowledge: Surgical techniques which can be employed to minimize brain shift in the operating room setting are critical for reduction in variation of the final DBS lead placement. Pneumocephalus after dural opening is one potential cause of brain shift. The recognition that the removal of a guide-tube cannula could worsen brain shift creates an opportunity for an intraoperative team to maintain the advantage of the 'fork' in the brain provided by the initial procedure's requirement of guide-tube placement.

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.

Sudden-onset, non-traumatic large volume pneumocephalus following presentation of acute bacterial meningitis.

A man in his 30s, with sinonasal undifferentiated carcinoma status post resection 6 years prior, presented with acute onset of fever, headache and altered mentation. The patient was diagnosed with bacteremia and meningitis due to Streptococcus pneumoniae A standard antibiotic and corticosteroid regimen was started. Brain MRI showed an encephalocele abutting the superolateral nasopharynx mucosa. After several days of clinical improvement, the patient's mental status and headache acutely relapsed. A CT head venogram showed a large volume pneumocephalus originating from the region of a surgical defect. Management included external ventricular drain placement followed by right pterional craniotomy with skull base packing. Skull base defects increase the risk of life-threatening conditions such as bacterial meningitis and pneumocephalus. It is crucial for clinicians to be aware of the possibility of cranial surgical defects developing years after surgery.

Spinal procedures, pneumocephalus, and cranial nerve palsies: A review of the literature.

Purpose: Minimally invasive and surgical spine procedures are commonplace with various risks and complications. Cranial nerve palsies, however, are infrequently encountered, particularly after procedures such as lumbar punctures, epidural anesthesia, or intrathecal injections, and are understandably worrisome for clinicians and patients as they may be interpreted as secondary to a sinister etiology. However, a less commonly considered source is a pneumocephalus which may, in rare cases, abut cranial nerves and cause a palsy as a benign and often self-resolving complication. Here, we present the case of a patient who underwent an intrathecal methotrexate infusion for newly diagnosed non-Hodgkin's T-cell lymphoma and subsequently developed an abducens nerve palsy due to pneumocephalus. We highlight the utility of various imaging modalities, treatment options, and review current literature on spinal procedures resulting in cranial nerve palsies attributable to pneumocephalus presenting as malignant etiologies.

Laparoscopic cholecystectomy induce tension pneumocephalus in a patient with ventriculoperitoneal shunt: A case report and literature review.

INTRODUCTION AND PATIENT CONCERNS: We report on a 45-year-old woman who has a ventriculoperitoneal shunt (VPS), experienced drowsy mental status, with hypesthesia and hemiplegia on the left side. Ten days ago she underwent laparoscopic cholecystectomy (LC). Computed tomography revealed tension pneumocephalus, with severe compression on the right side of the brain. INTERVENTIONS AND DIAGNOSIS: She underwent 2 surgeries, the first surgery was to place a subdural drainage catheter, however, the pneumocephalus relapsed after withdrawing the catheter, and the later surgery was to replace the new VPS. OUTCOMES: After replacing the VPS, the patient recovers completely after 10 weeks of follow-up. CONCLUSION: To our knowledge, this is the first report of LC-induced tension pneumocephalus in a patient with VPS. The purpose of this study is to share our experience, with the hypothesized mechanism being the retrograde air through the VPS valve because of high abdominal pressurization. We recommend noting the existence of the VPS when the LC or any abdominal laparoscopy is performed. The VPS should be clamped during any laparoscopic procedure until complete depressurization. Furthermore, all patients with VPS who have neurological deterioration after abdominal laparoscopy should be treated as having the diagnosis of a tension pneumocephalus. These patients need emergency surgery to replace VPS and set the valve for high-pressure, which can result in a quick and complete recovery.

Clinical Significance of Pneumocephalus in Pediatric Mild Traumatic Brain Injury.

OBJECTIVES: Mild traumatic brain injury (mTBI) comprises most (70%-90%) of all pediatric head trauma cases seeking emergency care. Although most mTBI cases have normal initial head computed tomography scan, a considerable portion of the cases have intracranial imaging abnormalities on computed tomography scan. Whereas other intracranial pathological findings have been extensively studied, little is known about the clinical significance of pneumocephalus in pediatric mTBI. METHODS: We retrospectively identified pediatric mTBI patients with pneumocephalus using the institutional database of a large regional trauma referral center. Outcome measures were defined as clinically important TBI (ciTBI), hospitalization, intensive care unit (ICU) admission, and neurosurgical intervention. Comparisons were made between pneumocephalus and control (isolated linear fracture) groups as well as between isolated (only linear fracture and pneumocephalus) and nonisolated pneumocephalus (pneumocephalus and TBI) groups. RESULTS: Among 3524 pediatric mTBI cases, 43 cases had pneumocephalus (1.2%). Twenty-one cases (48.8%) had isolated pneumocephalus. The pneumocephalus group had higher rates of ciTBI, hospital admission, ICU admission, and neurosurgery when compared with the isolated linear fracture (control) group. The isolated pneumocephalus group had fewer ciTBI (21.1% vs 70%, P = 0.002), fewer hospitalization (23.8% vs 81.8%, P < 0.001), but similar ICU admission rates (4.8% vs 22.7%, P = 0.089) and length of hospital stay (4.0 ± 2.7 vs 3.6 ± 2.4 days, P = 0.798) in comparison to the nonisolated pneumocephalus group. None of the patients in the isolated group had neurosurgery whereas 2 patients in the nonisolated pneumocephalus group underwent surgery. Multivariable analysis revealed pneumocephalus as an independent predictor of ciTBI and hospital admission, but not ICU admission or neurosurgical intervention. CONCLUSION: Pneumocephalus is associated with increased rates of hospitalization and ciTBI, but not ICU admission, unfavorable outcome, or neurosurgical intervention in pediatric mTBI. Although usually spontaneously resolving pathology, it may occasionally be linked with complications such as cerebrospinal fluid leakage, meningitis, and tension pneumocephalus. Therefore, careful evaluation, close observation, and early detection of complications may prevent adverse outcomes.

Modified Puerto Rico Recurrence Scale for chronic subdural hematomas: augmenting the grading scale with postoperative pneumocephalus volume.

BACKGROUND: Chronic subdural hematomas (CSDHs) are common in the elderly, with a relatively high rate of recurrence after initial surgical intervention. Our research team previously created a predictive grading system, the Puerto Rico Recurrence Scale (PRRS), to identify patients at high risk of CSDH recurrence. In this study, we introduce a modification of the (mPRRS) that includes pneumocephalus volume, which has been independently associated with recurrence. METHODS: A single-center Puerto Rican population-based retrospective study was performed to analyze data for patients treated for CSDH at 1 institution between July 1, 2017, and December 31, 2019. Univariate and multivariate analyses were used to create a grading scale predictive of recurrence. Retrospective validation was conducted for the cohort. RESULTS: Of 108 patients included in the study, 42 had recurrence, and 66 had nonrecurrence. Postoperative subdural space, postoperative midline shift, and pneumocephalus volume were all higher with recurrence (P = 0.002, P = 0.009, and P < 0.001, respectively). Multivariate analysis was used to create a 6-point grading scale comprising 3 variables (pneumocephalus volume [< 10, 10-20, 21-30, and > 30 cm3], postoperative midline shift [< 0.4, 0.41-1.0, and > 1.0 cm], and laterality [unilateral and bilateral]). Recurrence rates progressively increased in low-risk to high-risk groups (2/18 [11%] vs 21/34 [62%]; P < 0.003). CONCLUSION: The mPRRS incorporating pneumocephalus measurement improves CSDH recurrence prediction. The mPRRS indicated that patients with higher scores have a greater risk of recurrence and emphasized the importance of measuring postoperative variables for prediction. The mPRRS grading scale for CSDHs may be applicable not only to the Puerto Rican population but also to the general population.

Tension pneumocephalus in a patient with NF1 following ventriculoperitoneal shunt-deciphering the cause and proposed management strategy.

INTRODUCTION: Spontaneous pneumocephalus following ventriculoperitoneal shunting is a very unique complication, seen in a handful of patients. Small bony defects form as a result of chronically raised intracranial pressure, which can later lead to pneumocephalus once intracranial pressure decreases following ventriculoperitoneal shunting. CASE REPORT: Here, we present a case of a 15-year-old girl with NF1 who presented to us with pneumocephalus 10 months following shunting and our management strategy along with a literature review of this condition. CONCLUSION: NF1 & hydrocephalus can lead to skull base erosion, which needs to be looked up before proceeding with VP shunting to avoid delayed onset pneumocephalus. SOKHA with the opening of LT is a minimally invasive approach suitable to tackle both problems simultaneously.