Infrastructural Limitations in Establishing Neurosurgical Specialty Services in Liberia

Introduction

Liberia recently employed the first neurosurgeon in the country’s history. In a country with a population of 4.7 million people and staggering rates of cranial and spine trauma, as well as hydrocephalus and neural tube defects, neurosurgery is considered a luxury. Our study documents the experience of a team of neurosurgeons, critical care nurses, scrub technicians, nurses, and biomedical engineers who carried out a series of neurosurgical clinics and complex brain and spine surgeries in Liberia. Specifically, we aim to highlight some of the larger obstacles, beyond staff and equipment, facing the development of a neurosurgical or any other specialty practice in Liberia. 

Methods

Our institutions, in collaboration with the Korle-Bu Neuroscience Foundation, spent 10 days in Liberia, based in Tappita, and performed 18 surgeries in addition to seeing several hundred clinic patients. This is a retrospective review of the cases performed along with outcomes to investigate obstacles in providing neurosurgical services in the country.

Results

Before arriving in Liberia, we evaluated, planned, and supplied staff and materials for treating complex neurosurgical patients. Sixteen patients underwent 18 surgeries at a hospital in Tappita, Liberia, in November 2018. Their ages ranged from 1 month to 72 years (average 20 years). Five patients (28%) were female. Ten patients (56%) were under the age of 18. Surgeries included ventriculoperitoneal shunting (VP-shunt), lumbar myelomeningocele repair, encephalocele repair, laminectomy, and a craniotomy for tumor resection. Ten patients (55%) underwent VP-shunting. Two patients (11%) had a craniotomy for tumor resection. Three patients (17%) had laminectomy for lumbar stenosis. Two patients (11%) had repair of lumbar myelomeningocele.

Conclusion

After an aggressive and in-depth approach to planning, conducting, and supplying complex neurosurgical procedures in Liberia, the greatest limiting factor to successful outcomes lie in real-time is access to health care, which is largely limited by overall infrastructure. Our study documents the experience of a team of neurosurgeons, critical care nurses, scrub technicians, nurses, and biomedical engineers who carried out a series of neurosurgical clinics and complex brain and spine surgeries in Liberia. Specifically, we aim to highlight some of the larger obstacles, beyond staff and equipment, facing the development of a neurosurgical or any other specialty procedural practice in the country of Liberia. Most notably, we focus on infrastructure factors, including power, roads, water, education, and overall health care. 

Pathophysiologic Mechanisms of Concussion, Development of Chronic Traumatic Encephalopathy, and Emerging Diagnostics: A Narrative Review

Pathophysiological mechanisms and cascades take place after a mild traumatic brain injury (mTBI) that can cause long-term sequelae, including chronic traumatic encephalopathy in patients with multiple concurrent TBIs. As diagnostic imaging has become more advanced, microanatomical changes present after mTBI may now be more readily visible. In this narrative review, the authors discuss emerging diagnostics and findings in mTBI through advanced imaging, electroencephalograms, neurophysiologic processes, Q2 biochemical markers, and clinical tissue tests in an effort to help osteopathic physicians to understand, diagnose, and manage the pathophysiology behind mTBI, which is increasingly prevalent in the United States.

A Novel Method for Practicing Fascial Closure with Suture

Closure of the fascial layer can be challenging to learn for junior level residents. Wound dehiscence involving the fascial layer can lead to complicated clinical courses for patients, including readmission to the hospital, wound vacuum placement, antibiotic regimens, and re-operation. Typical suturing techniques taught in medical school focus more on basic techniques of suture placement such as interrupted or running techniques. The aim of this study is to introduce a method of practicing fascial closure using easily obtainable items. Though there is no substitute for placement of suture and closure of fascia in vivo, this method allows one to practice the motor repetition of fascial suture placement and provides one with the ability to check their work.

Increased Brain Tissue Oxygen Monitoring Threshold to Improve Hospital Course in Traumatic Brain Injury Patients

Introduction

This article is a retrospective analysis of the neurosurgical census at our institution to determine an optimal threshold for brain tissue oxygenation (PbtO2). The use of brain tissue oxygen monitoring has been in place for approximately three decades but data suggesting optimal thresholds to improve outcomes have been lacking. Though there are multiple modalities to monitor cerebral oxygenation, the monitoring of brain tissue oxygen tension has been deemed the gold standard. Still, it is not clear exactly how reductions in PbtO2 should be treated or what appropriate thresholds to treat might be. The aim of our study was to determine if our threshold of 28 mmHg for a good functional outcome could be correlated to the Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS).

Methods

A retrospective analysis of the Arrowhead Regional Medical Center (ARMC) Neurosurgery Census was performed. Patients from 2017-2019 who had placement of Licox® cerebral oxygen monitoring sensors (Integra® Lifesciences, Plainsboro Township, New Jersey) were included in the analysis. Fifteen patients were consecutively identified, all of which presented with traumatic brain injury (TBI). Data on age, gender, days in the intensive care unit (ICU), days before discharge or end of medical care, admission GCS, hospital length of stay, GOS, maximum and minimum PbtO2 values for five days following insertion, minimum and maximum intracranial pressures (ICPs), and brain temperature were included for analysis. Patient data were separated into two groups; those with consistently higher PbtO2 scores (≥ 28 mmHg; n = 7) and those with inconsistent/lower PbtO2 scores (< 28 mmHg; n = 8). Standard student t-tests were used to find potential statistical differences between the groups (α = 0.05).

Results

There were seven patients in the consistently high PbtO2 category (≥ 28 mmHg) and eight patients in the inconsistent/low PbtO2 category (<28 mmHg). The average maximum and minimum PbtO2 for the group displaying worse outcomes (as defined by GCS/GOS) was 23.0 mmHg and 14 mmHg, respectively. Those with consistent Day 2 PbtO2 scores of ≥ 28 mmHg had significantly higher GCS scores at discharge/end of medical care (p < 0.05). Average GCS for the patient group with >28 mmHg PbtO2 averaged over Days 2-5 group was 11.4 (n=7). Average GCS for the <28 group was 7.0 (n=8). The GCS for the >28 group was 63% higher than found in the <28 group (p = 0.03). GOS scores were significantly higher in those with consistently higher PbtO2 (≥ 28) than those with lower PbtO2 scores (< 28). The averages were 3.5 in the higher PbtO2 group as compared to 2 in the lower PbtO2 group.

Conclusion

Along with ICP monitors and monitoring in the assessment of CPP, brain tissue oxygenation allows yet another metric by which to optimize treatment in TBI patients. At our institution, a PbtO2 level of ≥ 28 mmHg is targeted in order to facilitate a good functional outcome in TBI patients. Keeping patients at this level improves GCS and GOS at discharge/end of medical treatment.

Seizure Prophylaxis in Traumatic Brain Injury: A Comparative Study of Levetiracetam and Phenytoin Cerebrospinal Fluid Levels in Trauma Patients with Signs of Increased Intracranial Pressure Requiring Ventriculostomy

Background

One of the most common life-threatening injuries to trauma patients arriving in the emergency department (ED) is traumatic brain injury (TBI). Traditionally, intravenous medications have been given as seizure prophylaxis in patients demonstrating signs of increased intracranial pressure (ICP), as post-traumatic seizures in trauma patients are associated with higher morbidity and mortality. Medications traditionally given for this indication such as phenytoin have been established to reach therapeutic levels in the cerebrospinal fluid (CSF) quickly and are effective in preventing post-traumatic seizures but often have a large side-effect profile. A newer medication that is being used for seizure prophylaxis in patients with epilepsy is levetiracetam. Levetiracetam typically has a better side effect profile, but it has not been demonstrated that the drug reaches therapeutic levels in the CSF as quickly as phenytoin. Studies have shown levetiracetam and phenytoin to be equivocal in the prevention of post-TBI seizure prophylaxis.

Methods

This was a prospective, randomized, case-control study at a Level II trauma center of adult patients (age >/= 18 years) who suffered severe TBI (sTBI) requiring the placement of an external ventricular drain (EVD) from May 2017 to June 2018. Twelve patients were randomly placed into one of two groups for the administration of antiepileptic medication (either levetiracetam or phenytoin), allowing for the subsequent serial collection of CSF for the analysis of therapeutic levels of antiepileptic medications. Levetiracetam or phenytoin was administered at standardized fixed doses per our neurosurgical center standard protocol. CSF was collected before either drug was administered, 60 minutes after completion of administration and 360 minutes after completion of drug administration. Data analysis was performed to compare the time frame for which therapeutic levels of the medications were achieved in the CSF. The published steady-state and therapeutic CSF level of levetiracetam is 32 mcg/ml and phenytoin is 2 mcg/ml.

Results

A trend was observed in which the closer the fixed dosage approximated the weight-based dosing of phenytoin, the more their CSF phenytoin level increased (and approximated the therapeutic range) with an associated R-squared value of 0.6274. This trend was not found in patients receiving levetiracetam.

Conclusions

Levetiracetam does not reach levels needed for seizure prophylaxis in human CSF when loaded at standard dosing regimens in the acute setting. Phenytoin does reach levels needed for seizure prophylaxis in human CSF with standardized regimen dosing when dosages approximate weight-based dosing. If needed, in the acute setting phenytoin should have additional doses given prior to six hours after the loading dose to achieve therapeutic CSF levels. 

Efficacy of Trauma Catheter and Mushroom Tip Catheter in Evacuation of Chronic Subdural Hematoma and Complications of Drain Placement

Objective The aim of this study was to assess the efficacy and complications of trauma catheter versus mushroom tip catheter placement in the evacuation of chronic subdural hematoma via twist drill craniostomy with closed system drainage. Background Chronic subdural hematoma (cSDH) is one of the most frequent neurosurgical pathologies in patients >70 years of age with an estimated incidence of 8.2 per 100,000 people per year. The most common risk factors for cSDH are advanced age, alcohol abuse, seizures, cerebrospinal fluid (CSF) shunts, coagulopathies, blood thinners, and patients at risk for falling. Twist drill craniostomy can be performed at the bedside under local anesthesia, making it an attractive treatment option, especially in poly-morbid patients who are poor surgical candidates. A closed drainage system is placed at the time of surgery to allow continuous drainage and promote postoperative brain expansion. Despite the increasing prevalence, limited literature exists to guide surgical management, particularly in terms of drain management and selection of catheter.  Methods This is a retrospective review of 205 patients from January 2007 to May 2017 at two-level high volume centers for the evaluation and treatment of cSDH. Inclusion criteria include patients >18 years of age with the radiographic presence of a subdural hematoma for greater than three weeks. All patients were managed with either a trauma catheter or mushroom tip catheter. All patients received computed tomography (CT) of the head without contrast prior to subdural drain placement and within 24 hours after subdural drain removal. Exclusion criteria include patients <18 years of age and patients with depressed skull fractures, vascular malformations, subdural empyema, subdural hygroma, or who initially underwent open craniotomy or burr-hole craniotomy. Results Drain efficiency in evacuating the cSDH was assessed using both radiographic and clinical markers. Analysis of 205 patients treated by twist drill craniostomy and the subsequent closed system drainage utilizing either the mushroom tip catheter or trauma catheter revealed that neither catheter was superior in producing a statistically significant change in the maximum thickness of the cSDH (p = 0.35) and midline shift (p = 0.45). Furthermore, when assessing patients clinically via utilization of the Glasgow Coma Scale (GCS), both the trauma catheter and the mushroom catheter did not show a statistically significant difference in improving GCS after the evacuation of the cSDH (p = 0.35). Neither catheter was associated with an increased incidence of hemorrhage with drain placement requiring open surgery (p = 0.12), need for additional drain placement (p = 0.13) or decline in GCS with intervention (p = 0.065). Conclusion Analysis of the 205 patients treated by twist drill craniostomy with closed system drainage for the evacuation of chronic subdural hematoma utilizing either the mushroom tip or trauma catheters revealed that neither catheter was statistically significant in radiographic or clinical improvement in evacuating cSDH. Furthermore, neither catheter was found to be associated with an increased complication risk.

The Use of Computed Tomography Perfusion on Admission to Predict Outcomes in Surgical and Nonsurgical Traumatic Brain Injury Patients

Introduction: The objective of this study was to investigate if data obtained from a computed tomography (CT) perfusion study on admission could correlate to outcomes for the patient, including the patient’s length of stay in the hospital and their initial and final Glasgow Coma Scale (GCS), as well as the modified Rankin Scale (mRS) on discharge. We present an initial subset of patients fulfilling the inclusion criteria: over the age of 18 with mild, moderate, or severe traumatic brain injury (TBI). Patients admitted with a diagnosis of TBI had CT perfusion studies performed within 48 hours of admission. GCS, length of stay, mRS, and discharge location were tracked, along with the patient’s course of hospitalization. Initial results and discussion on the utility of CT perfusion for predicting outcomes are presented.

Methods: Patients exhibiting mild, moderate, or severe TBI were assessed using CT perfusion within 48 hours of admission from January to July 2019 at the Arrowhead Regional Medical Center (ARMC). The neurosurgery census and patient records were assessed for progression of outcomes. Data obtained from the perfusion scans were correlated to patient outcomes to evaluate the utility of CT perfusion in predicting outcomes in surgical and nonsurgical TBI patients.

Results: Preliminary data were obtained on six patients exhibiting TBI, ranging from mild to severe. The mean GCS of our patient cohort on admission was eight, with the most common mechanism of injury found to be falls (50%) and motor vehicle accidents (50%). Cerebral blood volume (CBV) seemed to increase with Rankin value (Pearson's correlations coefficient = 0.43 but was statistically insignificant (P = 0.21)). Cerebral blood flow (CBF) was found to be correlated with CBV, and both increased with Rankin score (Pearson's correlation coefficient = 0.56) but were statistically insignificant (P = 0.27). These results suggest that with a larger sample size, CBV and CBF may be correlated to patient outcome.

Conclusion: Although more data is needed, preliminary results suggest that with larger patient populations, CT perfusion may provide information that can be correlated clinically to patient outcomes. This study shows that CBF and CBV may serve as useful indicators for prognostication of TBI patients.

Conditions associated with giant pituitary tumors at the time of surgery effecting outcome morbidity and mortality

Background:

Surgical outcome prediction has assisted physicians in discussing surgical intervention or expectant management. While increasing pituitary tumor size would seem to be associated with increasing challenge of removal and associated complications, that relationship has not been borne in the literature.

Methods:

We performed a retrospective review of a consecutive cohort of pituitary surgeries completed at our institution. Data included age at the time of surgery, presenting symptoms and Glasgow Coma scale (GCS), GCS at discharge or 7 days postoperatively, GCS at 6 months, adenoma size, imaging characteristics of the tumor and brain before resection, postoperative complications, the presence of preoperative hydrocephalus, brainstem compression, and patient mortality.

Results:

Patients with giant adenomas were more likely to present with a cranial nerve palsy (P = 0.019), altered mental status (P = 0.0001), hydrocephalus (P = 0.002), and mass effect on the brainstem (P = 0.020). Patients who experienced a postoperative decline in mental status were more likely to present with altered mental (P = 0.006), had an increased prevalence of mass effect on the brainstem (P = 0.005), and were more likely to have either an ischemic stroke (P = 0.0001) and vasospasms or new intraparenchymal hemorrhage (P = 0.013).

Conclusion:

The results of this study demonstrate that postoperative mental status declines after pituitary adenoma resection can be directly related to brainstem compression and further surgical irritation of the surrounding vasculature. The intraoperative irritation can be multifactorial and may result as the decompressed brain structures assume their anatomical position.

Gender Disparity in Academic Neurosurgery

Background In the 1960s, less than 10% of medical school graduates were women. Today, almost half of all medical school graduates are women. Despite the significant rise in female medical school graduates, there continues to be a large gender gap in most subspecialties, particularly surgical subspecialties such as neurosurgery. Objective The purpose of our study was to assess the factors contributing to differences in the academic ranks of male and female staff in academic neurosurgery programs in Canada and the United States (US). Methods Data about women in academic neurosurgery was collected from a number of sources, including Fellowship and Residency Electronic Interactive Database (FREIDA), Accreditation Council for Graduate Medical Education (ACGME), Canadian Resident Matching Service (CaRMS) FRIEDA, ACGME, CaRMS, Pubmed, and Scopus, to create a database of all neurosurgeons in the US and Canada. The analysis included neurosurgeons in academic and leadership ranks and also the H index, citations, publications, citations per year, and publications per year. Results Women represent only 12% of neurosurgeons in the US and Canada. When gender is further analyzed by academic appointment, women represent just over 12% of neurosurgeons at the assistant and associate professor levels (15.44% and 13.27%, respectively) but significantly less at the full professor level (5.84%). Likewise, only 7.45% of women hold first-in command leadership positions while 4.69% hold second-in-command positions within their institutions. Conclusions The existing data shows that women are significantly under-represented in academic neurosurgery. Lack of role models, experience, limited scientific output, and aspirations of a controlled lifestyle could be the potential contributing factors.

Superior Sagittal Sinus: A Review of the History, Surgical Considerations, and Pathology

A systematic PubMed and Google Scholar search for studies related to the anatomy, history, surgical approaches, complications, and diseases of the superior sagittal sinus was performed. The purpose of this review is to elucidate some of the more recent advances of our understanding of this structure. One of the earliest anatomical landmarks to be described, the superior sagittal sinus (SSS, sinus sagittalis superior (Latin); "sagittalis" Latin for 'arrow' and "sinus" Latin for 'recess, bend, or bay') has been defined and redefined by the likes of Vesalius and Cushing. A review of the various methods of approaching pathology of the SSS is discussed, as well as the historical discovery of these methods. Disease states that were emphasized include invasion of the SSS by meningioma, as well as thrombosis and vascular malformations.

Inflammatory Markers and Severity of Intracerebral Hemorrhage

Background and purpose

The pathogenesis of brain injury after intracerebral hemorrhage is thought to be due to mechanical damage followed by ischemic, cytotoxic, and inflammatory changes in the underlying and surrounding tissue.In recent years, there has been a greater research interest into the various inflammatory biomarkers and growth factors that are secreted during intracerebral hemorrhage. The biomarkers investigated in this study are tumor necrosis factor alpha (TNF alpha), C-reactive protein (CRP), homocysteine (Hcy), and vascular endothelial growth factor (VEGF). The aim of this study was to further investigate the effects of these biomarkers in predicting the acute severity outcome of intracerebral hemorrhage (ICH).

Methods

We conducted a retrospective chart review of patients with spontaneous ICH with TNF alpha, CRP, VEGF, and Hcy levels drawn on admission. Forty-two patients with spontaneous ICH with at least one of the above labs were included in the study. Primary outcomes included death, Glasgow Coma Scale (GCS) on admission, early neurologic decline (END), and hemorrhage size. Secondary outcomes included GCS on discharge, ICH score, functional outcome risk stratification scale of intracerebral hemorrhage (FUNC score), change in hemorrhage size, need for surgical intervention, and length of intensive care unit (ICU) stay.

Results

Forty-two patients with spontaneous intracerebral hemorrhage (ICH) were analyzed, 12 patients (28.5%) required surgical intervention, and four patients (9.5%) died. Only low VEGF serum values were found to predict mortality. TNF alpha, CRP, Hcy, and VEGF levels in our patients with ICH were not found to predict early neurologic decline and were not correlated with GCS on admission, initial hemorrhage size, change in hemorrhage size, need for surgical intervention, ICH score, FUNC score, midline shift, and length of ICU stay. CRP and Hcy were elevated in 58% and 31% of patients tested, respectively. GCS on admission and ICH score were significantly associated with mortality.

Conclusion

After careful statistical review of the data obtained from this patient population, only low VEGF values were found to be a significant predictor of mortality. However, elevated CRP and Hcy levels were associated with a non-significant trend in hemorrhage size and mortality suggesting that CRP and Hcy-lowering therapies may decrease hemorrhagic stroke risk and severity.

Will clinical parameters reliably predict external ventricular drain-associated ventriculitis: Is frequent routine cerebrospinal fluid surveillance necessary?

Background:

The placement of an external ventricular drain (EVD) for monitoring and treatment of increased intracranial pressure is not without risk, particularly for the development of associated ventriculitis. The goal of this study was to investigate whether changes in cerebrospinal fluid (CSF), serum, or clinical parameters are correlated with the development of ventriculitis before it occurs, allowing for the determination of optimal timing of CSF collection.

Methods:

An observational retrospective study was conducted between January 2006 and May 2012. A total of 466 patients were identified as having an in-situ EVD placed. Inclusion criteria were age >18 years, glasgow coma scale (GCS) 4-15, and placement of EVD for any indication. Exclusion criteria included recent history of meningitis, cerebral abscess, cranial surgery or open skull fracture within the previous 30 days. A broad definition of ventriculitis was used to separate patients into three initial categories, two of which had sufficient patients to proceed with analysis: suspected ventriculitis and confirmed ventriculitis. CSF sampling was conducted on alternating weekdays.

Results:

A total of 466 patients were identified as having an EVD and 123 patients were included in the final analysis. The incidence of ventriculitis was 8.8%. Only the ratio of glucose CSF: serum <0.5 was found to be of statistical significance, though not correlated to developing a ventriculitis.

Conclusions:

This study demonstrates no reliable tested CSF, serum, or clinical parameters that are effectively correlated with the development of ventriculitis in an EVD patient. Thus, we recommend and will continue to draw CSF samples from patients with in-situ EVDs on our current schedule for as long as the EVD remains in place.