Pneumocephalus after surgical evacuation of chronic subdural hematoma: Is it a serious complication?

Advances in pathogenic mechanisms, diagnostic methods, surgical and non-surgical treatment, and potential recurrence factors of Chronic Subdural Hematoma: A review

Chronic Subdural Hematoma (CSDH) is a common hemorrhagic disease in neurosurgery, and with the intensification of global aging, its incidence is gradually increasing. With the advancement of scientific technology, the etiological concepts and surgical treatments for CSDH have continually evolved over time. Currently, neuroscientists' understanding of CSDH is no longer confined to bridging vein rupture; exploration of various mechanisms such as angiogenesis, maturation of blood vessels, and inflammation is also underway. In-depth exploration and discovery of pathogenic mechanisms guide the updating of clinical treatment strategies and methods. For different types of CSDH, there is now a clear guidance for the targeted selection of treatment methods. However, the current treatment of CSDH cannot completely solve all problems, and the updating of treatment methods as well as the development and validation of new effective drugs remain challenges for the future. In addition, the recurrence of CSDH is a significant issue that needs to be addressed. Although we have reviewed potential recurrent factors that may be associated, the strength of this evidence is insufficient. Future research should gradually focus on validating these recurrent factors and exploring new ones, in order to optimize the existing understanding and treatment of CSDH.

Severe pneumocranium after gamma knife stereotactic radiosurgery for brain metastasis: A case report and literature review

RATIONALE

Gamma knife stereotactic radiosurgery (GKRS) is a recognized safe and effective treatment for brain metastasis; however, some complications can present significant clinical challenges. This case report highlights a rare occurrence of cerebrospinal fluid (CSF) leakage and pneumocranium following GKRS, emphasizing the need for awareness and prompt management of these complications.

PATIENT CONCERNS

A 35-year-old male with a history of malignant neoplasm of the lip in 2015 and perineural spread of malignancy into the left cavernous sinus was treated with GKRS in 2017. The patient was admitted emergently 39 days after discharge due to persistent headache and dizziness.

DIAGNOSES

Brain computed tomography (CT) revealed diffuse bilateral pneumocranium alongside an observation of CSF leakage.

INTERVENTIONS

A surgical procedure involving a left frontal-temporal craniotomy was performed to excise a residual skull base tumor and repair the dura, guided by a navigator system. The conclusive pathological assessment revealed the presence of squamous cell carcinoma markers.

OUTCOMES

The patient exhibited excellent tolerance to the entire procedure and experienced a prompt and uneventful recovery process. After surgery, the symptoms alleviated and CSF leak stopped. The follow-up image showed the pneumocranium resolved.

LESSONS

Pneumocranium due to early-stage post-GKRS is uncommon. The rapid tumor shrinkage and timing of brain metastasis spreading through the dura can lead to CSF leak and pneumocranium. We reviewed current treatment options and presented a successful craniotomy-based dura repair case.

Fatal postoperative tension pneumocephalus after acute subdural hematoma evacuation: a case report

PURPOSE

Tension pneumocephalus (TP) represents a rare pathology characterized by constant accumulation of air in the intracranial space, being associated with increased risk of herniation, neurologic deterioration and death. Regarding neurosurgical trauma cases, TP is majorly encountered after chronic subdural hematoma evacuation. In this case report, we present a rare case of fatal postoperative TP encountered after craniotomy for evacuation of acute subdural hematoma (aSDH).

CASE PRESENTATION

An 83-year old gentleman was presented to the emergency department of our hospital with impaired level of consciousness. Initial examination revealed Glascow Coma Scale (GCS) 3/15, with pupils of 3 mm bilaterally and impaired pupillary light reflex. CT scan demonstrated a large left aSDH, with significant pressure phenomena and midline shift. Patient was subjected to an uneventful evacuation of hematoma via craniotomy and a closed subgaleal drain to gravity was placed. The following day and immediately after his transfer to the CT scanner, he presented with rapid neurologic deterioration with acute onset anisocoria and finally mydriasis with fixed and dilated pupils. Postoperative CT scan showed massive TP, and the patient was transferred to the operating room for urgent left decompressive craniectomy, with no intraoperative signs of entrapped air intracranially. Finally, he remained in severe clinical status, passing away on the eighth postoperative day.

CONCLUSION

TP represents a rare but severe neurosurgical emergency that may be also encountered after craniotomy in the acute trauma setting. Involved practitioners should be aware of this potentially fatal complication, so that early detection and proper management are conducted.

Underwater versus Closed Drainage System for Surgical Treatment of Chronic Subdural Hematoma

OBJECTIVES

Chronic subdural hematoma (CDH) is a prevalent condition in neurosurgery. Standard care includes surgical evacuation with drainage of residual subdural cavity. We hypothesized that effective and timely drainage of subdural space may improve clinical and radiological outcomes. This study was conducted to compare the effectiveness of standard closed drainage and underwater drainage.

METHODS

Medical data of 300 surgically treated chronic subdural hematoma CDH patients were retrospectively collected and analyzed. The patients were divided into two 2 groups: Group I with underwater drainage, and Group II with closed drainage. Groups were compared in terms of gender, age, complication rates, recurrence rates, seizure rates, and length of hospital stay.

RESULTS

Underwater drainage was found superior to closed system by all clinical and radiographic parameters. The recurrence rate was significantly lower in Group I (2%) compared to with Group II (10%). Subdural empyema was observed in 10 patients in Group II and none in Group I. The seizure rate was higher in Group II (18%) compared to with Group I (5%). Postoperative pneumocephalus rates was were 20% in Group I and 54% in Group II. The length of hospital stay was 6±2.6 days in Group I and 8.9±6.1 days in Group II. The length of intensive care unit (ICU) stay was 0.6±1.12 days in Group I and 2.7±5 days in Group II. A minority (5%) of the patients in Group II required reoperation due to recurrence.

CONCLUSIONS

The use of underwater system significantly the reduces the rates of pneumocephalus, seizures, infection, and recurrence. Additional benefits are shorter intensive care unit ICU and total hospital stays.

Single-Center Comparison of Chronic Subdural Hematoma Evacuation Outcomes Under Local Versus General Anesthesia

BACKGROUND

Chronic subdural hematoma (CSDH) is a neurosurgical pathology of an aged populace. Pathogenetic risk factors include traumatic brain injury, prolonged use of antiplatelet drugs, hypertension, and some inflammatory processes. The incidence increases as patients age. Burr-hole evacuation is the most common approach in management of symptomatic cases. We compared evacuation of chronic subdural hematomas with general or local anesthesia (GA and LA, respectively) and evaluated the safety, economic benefits, effects of comorbidity, benefits, and shortcomings of both techniques.

METHODS

We conducted a retrospective study of 67 consecutive patients who had 74 procedures for CSDH in a single neurosurgical center, the Regional Clinic, Centre of Neurosurgery and Neurology, over a 3-year period. They were grouped into the GA group (n = 44) and LA group (n = 23). Mean duration of procedure, length of hospital stay, complications, and preoperative and postoperative neurologic statuses were compared. The distribution of nominal variables between groups was compared using the Fisher exact test. The average duration of operation and length of hospital stay were compared using the Mann-Whitney U-test due to violation of the normality assumption.

RESULTS

LA proved to be as effective as GA in CSDH evacuation. Seventy-four surgical procedures were performed on 67 patients due to recurrence in less than 30 days in 7 patients. Fifteen patients had tension pneumocephalus managed with fluid therapy to full recovery. LA was economical and required shorter hospital stays and surgical time.

CONCLUSIONS

In our studies, LA proved to be noninferior to GA, time conserving, and less prone to some of the adverse effects of GA on elderly patients with comorbidity, although some patients who are hyperactive or contraindicated to LA will require GA.

Tension pneumocephalus as a complication of surgical evacuation of chronic subdural hematoma: case report and literature review

The management of symptomatic chronic subdural hematoma (CSDH) is surgical evacuation and prognosis in most cases is good. Tension pneumocephalus is the presence of air under pressure in the intracranial cavity. A case of tension pneumocephalus developing as a complication of burr hole evacuation of CSDH is illustrated. In this case, tension pneumocephalus was managed by reopening the wound and saline irrigation with a subdural drain placement. Considering this case report and after a careful review of the literature, the physiopathology, diagnosis, and treatment of this complication are highlighted in the article.

Middle meningeal artery embolisation: The review of a new treatment for chronic subdural hematomas

Background

This is a literature review aiming to provide an update about the recent findings related to the efficacy of middle meningeal artery embolization (MMAE) in the treatment of chronic subdural hematomas (cSDHs), comparison with conventional therapy and deduction of the current recommendations and indications.

Methods

The literature is reviewed using a search through the PubMed index using keywords. Studies are then screened, skimmed, and thoroughly read. 32 studies fulfilled the inclusion criteria and are included in the study.

Results

Five indications for the application of MMA embolization (MMAE) are deducted from the literature. The usage as a preventive measure after surgical treatment of symptomatic cSDHs in patients with a high risk of recurrence and the usage as a standalone procedure has been the most common reasons for indication of this procedure. Rates of failures for the aforementioned indications have been 6.8% and 3.8%, respectively.

Conclusion

The safety of MMAE as a procedure is regarded as a general theme in the literature and can be considered for future applications. Usage of this procedure in clinical trials with more patient segregation and timeframe assessment relative to surgical intervention are recommendations of this literature review.

Postoperative pneumocephalus and recurrence and outcome of chronic subdural hematoma: a systematic review and meta-analysis

We conducted a meta-analysis to analyze the effects of pneumocephalus after chronic subdural hematoma (CSDH) surgery on hematoma recurrence, mortality, and functional outcomes. In this meta-analysis, following PRISMA guidelines, PubMed, Embase, Cochrane Library, and Web of Science online databases were queried using the keywords "pneumocephalus," "pneumoencephalos," "intracranial pneumatocele," "pneumo encephalon," "subdural air," and "chronic subdural hematoma." The results were limited to English-language articles. Through the online database, we identified a total of 276 articles and finally included 14 articles for meta-analysis. The results showed that the recurrence rate in the pneumocephalus group was higher than that in the control group, with a pooled OR of 3.35 (CI: 2.51-4.46, P < 0.001). There was no difference in recurrence rate between the no/few and moderate pneumocephalus groups (OR: 1.27, CI: 0.68-2.37, P = 0.46), but the recurrence rate of the large pneumocephalus group was significantly higher than that of the moderate group, with a pooled OR of 3.29 (CI: 1.71-6.32, P < 0.001). This study failed to show higher mortality and worse outcomes in the pneumocephalus group than in the control. Pneumocephalus after surgical evacuation of CSDH was associated with the recurrence rate of hematoma. Pneumocephalus affecting recurrence was correlated with gas volume, and moderate pneumocephalus may have less impact, while patients with large pneumocephalus are more likely to recur than those with moderate pneumocephalus. More prospective cohort studies are needed for further investigation and verification. This meta-analysis was registered (PROSPERO CRD42022321800).

Valve-controlled chronic subdural hematoma drainage: A feasibility study

INTRODUCTION

Pneumocephalus after chronic subdural hematoma (CSDH) evacuation is a potential predictor of hematoma recurrence.

RESEARCH QUESTION

To study the feasibility and safety of a novel CSDH evacuation technique using a valve-controlled method to avoid pneumocephalus.

MATERIAL AND METHODS

In a retrospective case series, we evacuated CSDH using very low-pressure valve-controlled drains and recorded the neurological, radiological, and functional outcomes. Patients with primary CSDH, without previous neurosurgical intervention, and who did not receive antiplatelet or anticoagulant therapy the week prior to the index surgery, were included in the study. Exclusion criteria were the evacuation with other treatment techniques and incomplete data files. Patients were assessed according to the Bender grading system to record the neurological status. The hematoma volume was estimated using the formula for ellipsoid volumes.

RESULTS

Thirty-six patients with a mean age of 73 years (±9 years) fulfilled our eligibility criteria. Our technique was effective since it decreased the CSDH volume from 141 ​ml (IQR 97 ​ml) to 20.6 ​ml (IQR 26.59 ​ml; p ​< ​0.001) and improved the neurological status according to the Bender grading system from two (IQR 0.25) to 1 (IQR 0). However, pneumocephalus and hematoma recurrence occurred in one case each (2.8%). At six months, all patients returned to their previous status, except for two patients (5.6%) who died due to irrelevant pathologies.

CONCLUSIONS

Valve-controlled CSDH evacuation aiming to decrease the postoperative pneumocephalus and hematoma recurrence constitutes an effective and safe alternative. However, larger randomized controlled studies are required to establish its role in CSDH management.

Solve the post-operative subdural pneumatosis of chronic subdural hematoma: A novel active bone hole drainage system

Background

Post-operative subdural pneumatosis (PSP) is commonly encountered after the chronic subdural hematoma (CSDH) surgery which currently lacks effective methods to avoid the condition. This study invented an active bone hole drainage system to change the venting technique with the aim of comparing post-operative efficacy and prognosis to traditional drilling and drainage.

Methods

We conducted a randomized controlled trial between January 2020 and January 2021. A total of 86 patients undergoing surgery were assessed for eligibility, with 50 patients randomly assigned to the control group (received drilling and drainage) and 36 patients to the test group (received modified surgery). The 6-month follow-up was done after surgery. CSDH recurrence and post-operative hematoma re-increasement were the primary endpoints. The data from the two groups were compared and analyzed. This study was registered with the Chinese Clinical Trials Register (ChiCTR2200057158), and had ethics committee approval and patient consent.

Results

The incidence of PSP in the test group (0%, 0/30)was lower than the control group (93.88%, 46/49) (P &lt; 0.001). The brain non-expansion rates 3 days/weeks/months after surgery of the test group were 59.25 [49.62, 76.97], 52.10 [42.88, 72.45], and 29.45 [23.40, 36.95] respectively, which were lower than the control group which were 78.60 [69.50, 94.70], 73.10 [60.70, 87.40], and 61.70 [51.50, 78.30], respectively (P &lt; 0.001). The ADL scores a week/month/3/6 months after surgery of the test group were 100.00 [60.00, 100.00], 100.00 [85.00, 100.00], 100.00 [100.00, 100.00], 100.00 [100.00, 100.00], which were better than the control group's 60.00 [60.00, 80.00], 75.00 [60.00, 100.00], 100.00 [60.00, 100.00], 100.00 [60.00, 100.00] (P &lt; 0.05). The incidence of primary endpoints in the test group (10%, 3/30) was lower than the control group (34.69%, 17/49) (P &lt; 0.05).

Conclusions

Compared to drilling and drainage, the modified surgery with the active bone hole drainage system significantly reduced the incidence of PSP and primary endpoints and improved the post-operative efficacy and prognosis.

Clinical trial registration

Identifier: ChiCTR2200057158.

Puerto Rico Recurrence Scale: Predicting chronic subdural hematoma recurrence risk after initial surgical drainage

Background:

Chronic subdural hematoma (CSDH) commonly affects older individuals and is associated with a relatively high rate of recurrence after surgery. Many studies have created grading systems to identify patients at high risk of CSDH recurrence after the initial surgery. However, no system has been adopted widely. The authors present the first CSDH grading system created from a population-based single-center data set.

Methods:

A single-center Puerto Rican population-based retrospective analysis was performed on consecutive patients treated for a CSDH at a designated institution from July 1, 2017 to December 31, 2019. Univariate and multivariate analyses were used to create a CSDH recurrence grading scale. Retrospective validation was conducted on this sample population.

Results:

The study included 428 patients. Preoperative midline shift, postoperative midline shift, and size of postoperative subdural space differed between the recurrence and nonrecurrence groups (P = 0.03, 0.002, and 0.002, respectively). A multivariate analysis was used to create a 10-point grading scale comprising four independent variables. Recurrence rates progressively increased from the low-risk (0–3 points) to high-risk (8–10 points) groups (2.9% vs. 20.3%; P < 0.001).

Conclusion:

A 10-point grading scale for CSDH recurrence was developed with four components: preoperative midline shift (≤1 and >1 cm), laterality (bilateral, unilateral-right, and unilateral-left), size of postoperative subdural space (≤1.6 and >1.6 cm), and pneumocephalus (present or absent). Patients who scored higher on the scale had a higher risk of recurrence. This CSDH grading scale has implications for Puerto Rico and the general population as the elderly population increases worldwide.

Pneumocephalus secondary to a spinal surgery: A literature review and a case report

Introduction

We report a case of pneumocephalus, which is identified as the presence of air in the cranial cavity and is a rare complication after spinal surgeries, in addition to a literature review of similarly reported cases.

Case presentation

The patient is a 63-year-old male who developed pneumocephalus after undergoing a minimally invasive left side decompression at L3-L4 with left L4 foraminotomy even though there were no signs of dural tears or Cerebrospinal Fluid (CSF) leaks. After the diagnosis of pneumocephalus using brain Magnetic Resonance Imaging (MRI), the patient was treated conservatively and was discharged after 3 weeks without developing further complications.

Discussion

Pneumocephalus is defined as an abnormal accumulation of air within the cranial cavity. It can occur due to a variety of causes but rarely due to gas forming bacteria. Many theories are suggested concerning the pathophysiology of pneumocephalus, the inverted bottle theory, the ball valve theory, the Nitrous Oxide (N₂O) theory, and as we outweigh in our case, gas forming bacteria theory. Pneumocephalus can be treated surgically, nevertheless, conservative management methods of such cases are usually followed.

Conclusion

The aim of this study is to draw further attention to the management and diagnosis of such surgical complication. A more extended research is needed to provide a full comprehensive approach to deal with this problem if faced in the future. To the best of our knowledge, this study reports the first pneumocephalus case induced by a postoperative bacterial infection in the global English based medical literature.

•

Pneumocephalus caused by gas forming infection in the spine is a rare complication after spinal surgery.

•

Unexplained headache spinal surgeries should raise suspicion toward pneumocephalus.

•

There are many theories regarding the development of pneumocephalus, each one need specific attention.

Fatal Acute Pneumocephalus after Bilateral Drainage for Chronic Subdural Hematomas: Case Report

BACKGROUND

 Pneumocephalus is a well-known complication in the surgical treatment of chronic subdural hematomas; however, its influence remains controversial. The amount of subdural air may vary, and it may cause worsening of symptoms, increase reoccurrence rates, and worsen the outcomes. Lethal outcome following acute onset of massive pneumocephalus was not previously reported.

CASE REPORT

 An 81-year-old man with bilateral hematomas underwent surgery under local anesthesia. Both hematomas were approached in the same surgery, and the drains were placed subdurally. After initial improvement, severe hypertension developed, followed by vital function and neurologic deterioration. Massive pneumocephalus with subarachnoid and contralateral intracerebral hemorrhage was revealed, causing a severe midsagittal shift. Emergency irrigation to evacuate subdural air was performed. However, there was no improvement. Further computed tomography confirmed subdural air collection, but it also revealed hemorrhage progression and intraventricular propagation. No further surgery was indicated.

CONCLUSION

 Pneumocephalus is an underestimated but potentially devastating complication. Both intraoperative avoidance and postoperative prevention should be utilized to avoid subdural air ingress, and thus evade potentially fatal complications.

Transorbital craniectomy for treatment of frontal lobe and olfactory bulb neoplasms in two dogs

CASE DESCRIPTION

An 8-year-old spayed female Shih Tzu crossbreed dog (dog 1) and a 13-year-old neutered male Miniature Fox Terrier (dog 2) were evaluated for removal of neoplasms involving both the frontal lobe and olfactory bulb.

CLINICAL FINDINGS

Physical examination revealed decreased menace response and behavioral changes in both dogs. For dog 1, neuroanatomic localization of the lesion was the left forebrain region; for dog 2, neuroanatomic localization of the lesion was the right forebrain region. Both dogs underwent CT, and dog 1 also underwent MRI. Results of diagnostic imaging were consistent with frontal lobe and olfactory bulb neoplasia in both cases. Dog 1 had lysis of the frontal bone adjacent to the neoplasm.

TREATMENT AND OUTCOME

Both dogs underwent a transorbital craniectomy to permit surgical tumor removal. Dog 1 was discharged from the hospital 48 hours after surgery, at which time its mentation and cranial nerve examination findings were considered normal. Dog 2 developed neurologic deterioration after surgery but was ultimately discharged from the hospital after 72 hours, at which time its mentation appeared normal.

CLINICAL RELEVANCE

The transorbital approach to the cranium provided excellent access to facilitate removal of frontal lobe and olfactory bulb neoplasms in these 2 dogs.

Delayed post-traumatic Tension Hydropneumocephalus; a Case Report of Conservative Treatment

Pneumocephalus refers to the presence of air in the cranial cavity. Trauma is the most common cause of acquired pneumocephalus. Tension pneumocephalus occurs when intracranial accumulation of air causes high pressure on the brain as compared to extracranial pressure. Tension pneumocephalus is usually acute, and causes neurological symptoms, and its delayed form rarely occurs. A 12-year-old girl presented with a headache, lethargy, mild fever, and nausea from two days before admission to emergency department of Shahid Rajaei Hospital, Qazvin, Iran. The patient had a history of head trauma in a driving accident six weeks before and had undergone brain computed tomography (CT) scan in another centre, which had revealed no sign of pneumocephalus. The patient had been treated for one week and had been discharged in good general condition.

Considering her reduced consciousness, the patient underwent brain CT scan again in our centre. CT scan revealed tension hydropneumocephalus. The patient was transferred to the intensive care unit (ICU) for treatment. Considering the trend of her recovery, the patient was a candidate for conservative non-surgical therapy based on the in-charge neurosurgery specialist’s decision. The patient reported no complications during the six-month follow-up. Delayed tension pneumocephalus is among neurosurgery emergencies usually treated with early surgical intervention and dura defect restoration, but this patient received non-surgical treatment without any serious problem during the six-month follow-up.

A simple and effective modified technique of twist drill craniostomy for bedside drainage and irrigation of chronic subdural hematoma: Technical and clinical study

OBJECTIVE

Chronic subdural hematoma (CSDH) is an important health problem observed mostly in elderly population. Here, we aimed to describe and validate a simple modified technique of twist-drill craniostomy (TDC) using easily accessible tools for effective and safe bedside CSDH drainage.

METHODS

A detailed description of the new modified TDC technique which allows for sequential drainage and irrigation under physiological conditions is provided. Clinical and radiological characteristics as well as surgical results of the patients undergoing this procedure are also presented.

RESULTS

A total of 55 patients (30 M, 25 F) underwent this modified TDC. Mean age was 61.7 ± 12.3 years. Medical comorbidities were common (76.4 %). Subdural hematoma was mostly unilateral (83.6 %). Maximum width of hematoma was 21 ± 4 mm on average (range: 9-38 mm). In total, patients underwent 1.6 ± 0.9 subdural tappings on average (median: 1, range: 1-5). Repeat tappings were performed in 43.6 % of the patients. No mortality, serious morbidity or infectious complications were noted. Pneumocephalus was either absent or minimal in most cases (96.4 %). Mean length of hospital stay was 4.9 ± 4.0 days (median: 3; range: 2-20 days). The clinical outcomes were favorable in 92.7 % of the patients (no craniotomy required and no symptomatic recurrence detected).

CONCLUSION

This modified technique of TDC utilizes easily available tools, yields satisfactory radiological and clinical results, allows repeated tappings even in outpatient settings and can thus be readily applied in every neurosurgical unit across the world. It can be an effective alternative to existing procedures for patients with multiple co-morbidities and/or high anesthesia risk, in emergency conditions and busy neurosurgical centers.

Finnish study of intraoperative irrigation versus drain alone after evacuation of chronic subdural haematoma (FINISH): a study protocol for a multicentre randomised controlled trial

INTRODUCTION

Chronic subdural haematomas (CSDHs) are one of the most common neurosurgical conditions. The goal of surgery is to alleviate symptoms and minimise the risk of symptomatic recurrences. In the past, reoperation rates as high as 20%-30% were described for CSDH recurrences. However, following the introduction of subdural drainage, reoperation rates dropped to approximately 10%. The standard surgical technique includes burr-hole craniostomy, followed by intraoperative irrigation and placement of subdural drainage. Yet, the role of intraoperative irrigation has not been established. If there is no difference in recurrence rates between intraoperative irrigation and no irrigation, CSDH surgery could be carried out faster and more safely by omitting the step of irrigation. The aim of this multicentre randomised controlled trial is to study whether no intraoperative irrigation and subdural drainage results in non-inferior outcome compared with intraoperative irrigation and subdural drainage following burr-hole craniostomy of CSDH.

METHODS AND ANALYSIS

This is a prospective, randomised, controlled, parallel group, non-inferiority multicentre trial comparing single burr-hole evacuation of CSDH with intraoperative irrigation and evacuation of CSDH without irrigation. In both groups, a passive subdural drain is used for 48 hours as a standard of treatment. The primary outcome is symptomatic CSDH recurrence requiring reoperation within 6 months. The predefined non-inferiority margin for the primary outcome is 7.5%. To achieve a 2.5% level of significance and 80% power, we will randomise 270 patients per group. Secondary outcomes include modified Rankin Scale, rate of mortality, duration of operation, length of hospital stay, adverse events and change in volume of CSDH.

ETHICS AND DISSEMINATION

The study was approved by the institutional review board of the Helsinki and Uusimaa Hospital District (HUS/3035/2019 §238) and duly registered at ClinicalTrials.gov. We will disseminate the findings of this study through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04203550.

Take it seriously or not: postoperative pneumocephalus in CSDH patients?

Background: Pneumocephalus is a common finding after burr-hole drainage of chronic subdural hematoma (CSDH). Its effects have not been specifically studied.Methods: A retrospective analysis was performed in 140 patients with CSDH with single burr-hole drainage. The pre- and postoperative volumes of intracranial hematoma and the postoperative volume of pneumocephalus were calculated and analyzed with their relationships with Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) scores.Results: The preoperative hematoma volume and the patient ages are positively correlated with the 1-day postoperative pneumocephalus volume (p < 0.001, p < 0.01). There is no correlation between postoperative pneumocephalus volume and GCS/GOS scores (p > 0.05) and there is no difference of GCS/GOS scores or CSDH recurrence rate between patients with and without pneumocephalus (p > 0.05). The age and the volume of 1-day postoperative pneumocephalus are positively correlated with the absorbing rate of pneumocephalus (p < 0.01, p < 0.001).Conclusions: The pneumocephalus at a certain range has no effect on the prognosis of patients with CSDH and requires no specific intervention due to its self-absorbing capacity in the normal progress after surgery.HighlightsNo correlation between postoperative pneumocephalus volume and GCS/GOS scores.No difference of GCS/GOS or recurrence between patients with pneumocephalus or not.Pneumocephalus at certain range has no effect on the prognosis of patients.

Acute parenchymal hemorrhage of three cases report after burr hole drainage of chronic subdural hematoma

Chronic subdural hematoma (CSDH) is one of the most common neurological diseases, which mainly occurs among elderly people and usually develop after minor head injuries. Over the years, a simple burr hole evacuation of the hematoma has been accepted as the widespread method for most cases of CSDH, but acute parenchymal hemorrhage is a rare and deadly complication after surgery. We report three elderly cases of post-operative parenchymal hemorrhage and analyse the underlying factors and formulate relevant strategies in this article. Three advanced age patients had been admitted to our department with gradually increasing headache and limb activity disorder urgently and underwent an emergency operation of burr hole drainage of CSDH in frontal-temporal region after preoperative evaluations and examinations. Unfortunately, acute post-operative parenchymal hemorrhage occurred in three advanced age patients. Ultimately, the patients achieved satisfying outcome with no significant neurological deficit through conservative treatment. The exact mechanism of such uncommon complications are difficult to explain and remain poorly understood. Advanced age, hypertension, amyloidosis, high perfusion triggered by rapid hematoma release, cerebrospinal fluid (CSF) loss, oral anticoagulant, primary disease aggravation were the main mechanisms which were speculated in our report. Simultaneously, positive measures could be adopt to prevent this rare complication.

Postoperative pneumocephalus increases the recurrence rate of chronic subdural hematoma

OBJECTIVES

Pneumocephalus is a common operative complication of chronic subdural hematoma. This study is to analyze the relationship between postoperative pneumocephalus and the recurrence and surgical outcomes.

PATIENTS AND METHODS

This is a retrospective case-cohort study, including a pneumocephalus group (n = 46) and a control group (n = 181). Their recurrence rates, CT attenuation values, hospital stay, healing time and the neurological status were recorded and analyzed.

RESULTS

The pneumocephalus group had a recurrence rate of 32.6%, significantly higher than the control (17.7%). In addition, the pneumocephalus group had a higher rate of postoperative epilepsy (21.7% vs 3.3%), longer hospital stay (11.5 ± 2.8 vs 7.8 ± 1.2 days), longer healing time (10.8 ± 5.4 vs 6.5 ± 2.3 months), and worse neurological scores than the control.

CONCLUSION

Pneumocephalus increases the recurrence rate of chronic subdural hematoma, and it not only prolongs the hospital stay and healing time, but also leads to deterioration of the neurological status.

Pneumocephalus: a rare and life-threatening, but reversible, complication after penetrating lumbar injury

Pneumocephalus, the presence of intracranial air, is a complication especially seen after neurotrauma or brain surgery. When it leads to a pressure gradient, a so-called tension pneumocephalus, it may require emergency surgery. Clinical symptomatology, especially in young children, does not differentiate between a pneumocephalus and a tension pneumocephalus. An additional CT scan is therefore warranted. Here, we report on a rare case of pneumocephalus after penetrating lumbar injury. Additionally, the pathophysiology of pneumocephalus, as well as its recommendations for diagnosis and treatment, will be elucidated.

Burr hole drainage and burr hole drainage with irrigation to treat chronic subdural hematoma: A systematic review and meta-analysis

OBJECTIVE

Numerous studies have investigated different operative procedures for treating chronic subdural hematoma (CSDH); however, the results are controversial. This meta-analysis was performed to evaluate the efficacy of burr hole drainage without irrigation (BHD) and burr hole drainage with irrigation (BHDI) for CSDH.

METHODS

We searched the following electronic databases to identify all studies from their inception to September 2017: Cochrane Library, Science Direct, MEDLINE, EMBASE, Scopus, Google Scholar, the China Biomedical Database (CBM), and the Chinese National Knowledge Infrastructure (CNKI). Randomized clinical trials (RCTs), prospective cohort studies, retrospective observational cohort studies, and case-control studies investigating BHD and BHDI for the treatment of CSDH were included. The Cochrane Collaboration's RevMan 5.3 software was used for meta-analysis.

RESULTS

In total, 7 retrospective cohort studies and 2 RCTs involving 993 participants were included. Comprehensive analysis results of 9 studies indicated that the recurrence of the BHDI was similar to that in BHD (odds ratio [OR] = 1.27, 95% confidence interval [CI] = .61-2.63, P = .53). Moreover, analysis for comparing recurrence in the 2 RCTs was not significantly different (OR = 1.14, 95% CI = .16-8.24, P = .95).In addition, meta-analysis of pneumocephalus (OR = 5.91, 95% CI = .61-56.86, P = .12) and mortality (OR = 0.94, 95% CI 0.14-6.16, P = .95) was not significantly different.

CONCLUSIONS

The results of this meta-analysis demonstrated that procedures with or without irrigation in the treatment of CSDH might have similar effect regarding recurrence and complications; therefore, irrigation might not be necessary. However, well-conducted RCTs and high-quality observational studies are still required to corroborate this issue.

Bi-frontal pneumocephalus is an independent risk factor for early postoperative agitation in adult patients admitted to intensive care unit after elective craniotomy for brain tumor: A prospective cohort study

Postoperative agitation frequently occurs after general anesthesia and may be associated with serious consequences. However, studies in neurosurgical patients have been inadequate. We aimed to investigate the incidence and risk factors for early postoperative agitation in patients after craniotomy, specifically focusing on the association between postoperative pneumocephalus and agitation. Adult intensive care unit admitted patients after elective craniotomy under general anesthesia were consecutively enrolled. Patients were assessed using the Sedation-Agitation Scale during the first 24 hours after operation. The patients were divided into two groups based on their maximal Sedation-Agitation Scale: the agitation (Sedation-Agitation Scale ≥ 5) and non-agitation groups (Sedation-Agitation Scale ≤ 4). Preoperative baseline data, intraoperative and intensive care unit admission data were recorded and analyzed. Each patient's computed tomography scan obtained within six hours after operation was retrospectively reviewed. Modified Rankin Scale and hospital length of stay after the surgery were also collected. Of the 400 enrolled patients, agitation occurred in 13.0% (95% confidential interval: 9.7-16.3%). Body mass index, total intravenous anesthesia, intraoperative fluid intake, intraoperative bleeding and transfusion, consciousness after operation, endotracheal intubation kept at intensive care unit admission and mechanical ventilation, hyperglycemia without a history of diabetes, self-reported pain and postoperative bi-frontal pneumocephalus were used to build a multivariable model. Bi-frontal pneumocephalus and delayed extubation after the operation were identified as independent risk factors for postoperative agitation. After adjustment for confounding, postoperative agitation was independently associated with worse neurologic outcome (odd ratio: 5.4, 95% confidential interval: 1.1-28.9, P = 0.048). Our results showed that early postoperative agitation was prevalent among post-craniotomy patients and was associated with adverse outcomes. Improvements in clinical strategies relevant to bi-frontal pneumocephalus should be considered.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02318199).

Burr-Hole Craniostomy with T-Tube Drainage as Surgical Treatment for Chronic Subdural Hematoma

OBJECTIVE

We sought to investigate the effect of burr-hole craniostomy with T-tube drainage to treat chronic subdural hematoma (CSDH).

METHODS

Eighty-seven patients with CSDH who were recruited from January 2012 to June 2017 at the Department of Neurosurgery, The First Affiliated Hospital of Xi'an Medical University, were divided into 2 groups according to the method of drainage: T-tube drainage system (n = 45) and conventional subdural drainage system (n = 42). Retrospective analysis of clinical data and efficacy was performed between the 2 groups.

RESULTS

There were no significant differences in age, preoperative Markwalder grade scale, preoperative hematoma volume, hospitalization days, and discharge Markwalder grade scale between the 2 groups (P > 0.05). The incidence of postoperative complications and hematoma recurrence in the group of patients with T-tube drainage was significantly reduced when compared with conventional subdural drainage systems (P < 0.05).

CONCLUSIONS

Both methods were effective in the treatment of CSDH; however, we found a lower overall surgical complication rate following treatment with burr-hole craniostomy and T-tube drainage. This indicates that it may be a better therapeutic option for management of CSDH.

Predictors of ventricular tension pneumocephalus after posterior fossa surgery in the sitting position

BACKGROUND

Ventricular pneumocephalus is a rare but potentially life-threatening complication of cranial surgery in the sitting position.

OBJECTIVE

The objective of the study is to assess the incidence and risk factors of postoperative ventricular pneumocephalus.

METHODS

We performed a retrospective chart review of 307 consecutive patients (147 men, 160 women) treated at our institution by intracranial surgery in the sitting position from January 2010 to October 2014. Ventricular air entrapment with lack of arousal or neurologic deterioration requiring external ventriculostomy (EVD) was defined as ventricular tension pneumocephalus (VTP). Demographic variables were recorded along with radiological and clinical data. The occurrence of pneumocephalus was correlated with patient-related and surgical variables.

RESULTS

VTP was observed in 12 cases (3.9%). These patients had higher intraventricular air volumes (48.5 cm³ (CI 95% [29.06-67.86])) compared to asymptomatic patients (7.4 cm³ (CI 95% [5.43-9.48])). Opening of the fourth ventricle was the most potent predictor of VTP (OR = 34.7, CI 95% [4.4-273.5], p = 0.001). In patients undergoing no additional treatment for pneumocephalus, ventricular air volume declined to an average of 41.7% of the initial postoperative volume on postoperative day 3.

CONCLUSIONS

Entrapment of intracranial and particularly ventricular air requiring emergent EVD occurred in 3.9% cases of intracranial surgery in the sitting position. Especially the opening of the fourth ventricle was associated with the development of VTP, which should warrant particularly diligent postoperative observation of these patients. In cases without neurological symptoms, the rate of spontaneous air resorption is sufficiently high to warrant expectant management.

Risk for intracranial pressure increase related to enclosed air in post-craniotomy patients during air ambulance transport: a retrospective cohort study with simulation

Background

Post-craniotomy intracranial air can be present in patients scheduled for air ambulance transport to their home hospital. We aimed to assess risk for in-flight intracranial pressure (ICP) increases related to observed intracranial air volumes, hypothetical sea level pre-transport ICP, and different potential flight levels and cabin pressures.

Methods

A cohort of consecutive subdural hematoma evacuation patients from one University Medical Centre was assessed with post-operative intracranial air volume measurements by computed tomography. Intracranial pressure changes related to estimated intracranial air volume effects of changing atmospheric pressure (simulating flight and cabin pressure changes up to 8000 ft) were simulated using an established model for intracranial pressure and volume relations.

Results

Approximately one third of the cohort had post-operative intracranial air. Of these, approximately one third had intracranial air volumes less than 11 ml. The simulation estimated that the expected changes in intracranial pressure during ‘flight’ would not result in intracranial hypertension. For intracranial air volumes above 11 ml, the simulation suggested that it was possible that intracranial hypertension could develop ‘inflight’ related to cabin pressure drop. Depending on the pre-flight intracranial pressure and air volume, this could occur quite early during the assent phase in the flight profile.

Discussion

These findings support the idea that there should be radiographic verification of the presence or absence of intracranial air after craniotomy for patients planned for long distance air transport.

Conclusions

Very small amounts of air are clinically inconsequential. Otherwise, air transport with maintained ground-level cabin pressure should be a priority for these patients.

Organized Chronic Subdural Hematomas Treated by Large Craniotomy with Extended Membranectomy as the Initial Treatment

Objective:

The aim of this retrospective study is to evaluate the efficacy and incidence of complications of craniotomy and membranectomy in elderly patients for the treatment of organized chronic subdural hematoma (OCSH).

Materials and Methods:

We retrospectively reviewed a series of 28 consecutive patients suffering from OCSH, diagnosed by magnetic resonance imaging (MRI) or computer tomography (CT) to establish the degree of organization and determine the intrahematomal architecture including inner membrane ossification. The indication to perform a primary enlarged craniotomy as initial treatment for nonliquefied OCSH with multilayer loculations was based on the hematoma MRI appearance – mostly hyperintense in both T1- and T2-weighted images with a hypointense web- or net-like structure within the hematoma cavity or inner membrane calcification CT appearance - hyperdense. These cases have been treated by a large craniotomy with extended membranectomy as the initial treatment. However, the technique of a burr hole with closed system drainage for 24–72 h was chosen for cases of nonseptated and mostly liquefied Chronic Subdural Hematoma (CSDH).

Results:

Between 1998 and 2015, 148 consecutive patients were surgically treated for CSDH at our institution. Of these, 28 patients which have OSDH underwent a large craniotomy with extended membranectomy as the initial treatment. The average age of the patients was 69 (69.4 ± 12.1). Tension pneumocephalus (TP) has occurred in 22.8% of these patients (n = 28). Recurring subdural hemorrhage (RSH) in the operation area has occurred in 11.9% of these patients in the first 24 h. TP with RSH was seen in 4 of 8 TP patients (50%). Large epidural air was seen in one case. Postoperative seizures requiring medical therapy occurred in 25% of our patients. The average stay in the department of neurosurgery was 11 days, ranging from 7 to 28 days. Four patients died within 28 days after surgery; mortality rate was 14.28%.

Conclusion:

Large craniotomy and extended membrane excision for OSDH still carry a high rate of mortality and morbidity in elderly patients. TP, RSH, and postoperative seizures are frequently seen complications in elderly patients.

Central hyperventilation syndrome due to massive pneumocephalus after endoscopic third ventriculostomy: a case report

Pneumocephalus is common after brain surgeries, but usually is not substantial enough to cause serious complications. We recently encountered a case of post-operative tachypnea after an endoscopic 3rd ventriculostomy. At first, we thought that the hyperventilation was the result of residual paralysis after emergence from anesthesia, but during further evaluation we found a massive pneumocephalus. In such unusual post-operative situations, physicians should consider surgery-related complications as the possible cause as well, along with the anesthetic factors.

[Tension pneumocephalus after surgical treatment of a bilateral chronic subdural hematoma: a banal and serious complication]

The occurrence of postoperative pneumocephalus is a common event and is often trivial. When the intracranial air volume is significant, it creates intracranial hypertension causing tension pneumocephalus. This case report describes the occurrence of tension pneumocephalus after surgical drainage of bilateral chronic subdural hematoma. The pneumocephalus was responsible for severe postoperative neurological deterioration. The attending physicians should be aware of the possibility of occurrence of such complication. Treatment and prevention of pneumocephalus should also be well known by the medical staff.

Treatment of acute subdural hematoma

OPINION STATEMENT

Clinical presentation, neurologic condition, and imaging findings are the key components in establishing a treatment plan for acute SDH. Location and size of the SDH and presence of midline shift can rapidly be determined by computed tomography of the head. Immediate laboratory work up must include PT, PTT, INR, and platelet count. Presence of a coagulopathy or bleeding diathesis requires immediate reversal and treatment with the appropriate agent(s), in order to lessen the risk of hematoma expansion. Reversal protocols used are similar to those for intracerebral hemorrhage, with institutional variations. Immediate neurosurgical evaluation is sought in order to determine whether the SDH warrants surgical evacuation. Urgent or emergent surgical evacuation of a SDH is largely influenced by neurologic examination, imaging characteristics, and presence of mass effect or elevated intracranial pressure. Generally, evacuation of an acute SDH is recommended if the clot thickness exceeds 10 mm or the midline shift is greater than 5 mm, regardless of the neurologic condition. In patients with patients with an acute SDH with clot thickness <10 mm and midline shift <5 mm, specific considerations of neurologic findings and clinical circumstances will be of importance. In addition, consideration will be given as to whether an individual patient is likely to benefit from surgery. For an acute SDH, evacuation by craniotomy or craniectomy is preferred over burr holes based on available data. Postoperative care includes monitoring of resolution of pneumocephalus, mobilization and drain removal, and monitoring for signs of SDH reaccumulation. Medical considerations include seizure prophylaxis and management as well as management and resumption of antithrombotic and anticoagulant medication.