Cervical Oblique Corpectomy: Revitalizing the Underused Surgical Approach With Step-By-Step Simulation in Cadavers.

ABSTRACT: Recently, the World Federation of Neurosurgical Societies Spine committee recommended that additional research on cost-benefit analysis of various surgical approaches for cervical spondylotic myelopathy be carried out and their efficacy with long-term outcomes be compared. Unfortunately, it is highly probable that the oblique corpectomy (OC) will not be included in cost-benefit investigations due to its infrequent application by neurosurgeons dealing with the spine. In this cadaveric study, head and necks of 5 adult human cadavers stained with colored latex and preserved in 70% alcohol solution were dissected under a table-mounted surgical microscope using 3× to 40× magnifications. The OC approach was performed to simulate real surgery, and the neurovascular structures encountered during the procedure and their relations with each other were examined. Oblique corpectomy was performed unilaterally, although neck dissections were performed bilaterally on 10 sides in all 5 cadavers. At each stage of the dissection, multiple three-dimensional photographs were obtained from different angles and distances. For an optimal OC, both the anterior spinal cord must be sufficiently decompressed and sufficient bone must be left in place to prevent instability in the cervical spine. Oblique corpectomy is a valid and potentially low cost alternative to other anterior and posterior approaches in the surgical treatment of cervical spondylotic myelopathy. However, meticulous cadaver studies are essential before starting real surgical practice on patients in order to perform it effectively and to avoid the risks of the technique.

Three pitfalls of accountable healthcare rationing.

A pandemic may cause a sudden imbalance between available medical resources and medical needs where fundamental care to a patient cannot be delivered. Inability to fulfil a professional commitment to deliver care as needed can lead to distress among caregivers and patients. This distress is sometimes alleviated through mechanisms that hide the facts that care is rationed and not all medical needs are met. We have identified three mechanisms that jeopardise accountable and optimal allocation of resources: (1) hidden value judgements that allow rationing under the disguise of triage or prioritisation, (2) disguised conflict of interest between societal and individual patient's needs and (3) concealed biases in the application of medical tools. Under these three pitfalls decisions of resource allocation and who gets treated are handled as medical decisions: normative decisions are concealed and perceived as falling with the realm of medical judgement. Value judgements and moral agency are hidden to offer a 'false sense of medical judgement', while in fact there are several ethical judgements and biases at stake. The three pitfalls entail hidden normative deliberation and are inappropriate for sustainable healthcare delivery and resource allocation. We believe it is necessary to maintain transparency in decision making under conditions of insufficient resources to maintain trust in professional care givers and secure fair treatment allocation. Recognition of the pitfalls, by applying our recommendations, may help to ensure transparent and accountable distribution of care and contribute to public acceptance of the ethics behind rationing.

Ethical triage during the COVID-19 pandemic: a toolkit for neurosurgical resource allocation.

BACKGROUND: The COVID-19 pandemic confronts healthcare workers, including neurosurgeons, with difficult choices regarding which patients to treat. METHODS: In order to assist ethical triage, this article gives an overview of the main considerations and ethical principles relevant when allocating resources in times of scarcity. RESULTS: We discuss a framework employing four principles: prioritizing the worst off, maximizing benefits, treating patients equally, and promoting instrumental value. We furthermore discuss the role of age and comorbidity in triage and highlight some principles that may seem intuitive but should not form a basis for triage. CONCLUSIONS: This overview is presented on behalf of the European Association of Neurosurgical Societies and can be used as a toolkit for neurosurgeons faced with ethical dilemmas when triaging patients in times of scarcity.

The probability of iatrogenic major vascular injury in lumbar discectomy.

Purpose: To estimate the frequency of iatrogenic injury of major vascular structures during lumbar discectomy.Materials and methods: The medical records of patients who underwent surgery for lumbar disc herniation at our neurosurgical clinic between April 2000 and April 2016 were retrospectively reviewed. Patients with intraoperative iatrogenic vascular injury were identified by reading the surgical notes and the post-operative progress records of patients who had undergone lumbar discectomy. The standard calculation of the incidence of iatrogenic major vascular injury in lumbar discectomy was used to analyse the data. The formula for estimating the standard probability by calculating the incidence rate is: [Formula: see text]=n/N, where [Formula: see text] is the estimated probability, n is the number of events and N is the total number of cases. The standard error of this estimate is SE[Formula: see text]=[Formula: see text]Results: During the study period, 2498 patients underwent lumbar discectomy at one or more levels of the lumbar spine. The operations were performed by more than 40 different neurosurgeons or surgical residents. More than 95% of the operations were done under a surgical microscope. Two cases were found to have iatrogenic major vascular injuries. The standard frequentist estimate of the probability, [Formula: see text] (risk-per-case), of iatrogenic major vascular injuries in lumbar discectomy was: [Formula: see text]=2/2498 = 0.0008 (0.08%). The standard error of this estimate was: [Formula: see text]=[Formula: see text]=0.000566 = 10-4 (5.66) (95% confidence interval for true p = 10-4 (801)±(1.96)×10-3 (566)).Conclusions: In this study, the incidence of iatrogenic major vascular injuries in lumbar discectomy was 1 in 1249 operations (0.08%). If utmost care is taken, at least some of these iatrogenic intraoperative vascular complications can be avoided or more rapidly treated, and the lives of such patients can be saved.

A New Perspective in Comparing Injuries Caused by Short-Duration External and Internal Forces in Saphenous Vein.

BACKGROUND: Great saphenous vein (GSV) graft failure is one of the major reasons for repeat bypass grafting. A comparison of the effects of simultaneous, short-duration, externally squeezing and internally distending forces on the same segment of ex-vivo human GSV has not yet been published, although similar studies have compared the experimental injury of different ex-vivo human veins. METHODS: Approximately 8-cm-long segments of GSV were harvested from each of the 15 patients. For each specimen, one end of the vein piece was occluded at a distance of 1 cm with an external cross-clamp for 5 min and the other end was similarly occluded at a distance of 1 cm by an endoluminal balloon. The middle sections of the veins, which were not occluded by any means, were taken as the control group. Two histologists, who were blinded to the groups, graded the hematoxylin and eosin (H&E) and Weigert-Van Gieson (WVG) stained sections semi-quantitatively and performed the histomorphometric measurements. RESULTS: The result of the histopathological evaluation of the intima layer showed that the microscopic scoring of lesions in the balloon group was significantly higher than that in the clamp and control groups (5.16 ± 1.32, 3.83 ± 0.75, and 1.00 ± 1.09, respectively; P < .001). In the adventitia layer, this level of scoring increased more in the clamp group than in the balloon and control groups (5.16 ± 1.16, 3.00 ± 0.89, and 0.16 ± 0.40, respectively, P < .001). CONCLUSION: Both the endoluminal balloon and external clamp techniques have harmful effects on the vein wall. Studying different kind of forces on different veins cannot provide us with reliable comparisons.

A New Method for Determining the Level of the Carotid Artery Bifurcation.

Exact localization of the bifurcation of the common carotid artery using skin surface landmarks is important for various diagnostic and therapeutic purposes, including emergency cases. Traditional methods have confirmed their accuracy in only a certain percentage of cases and there are inconsistencies among various publications. The cervical computed tomography-angiographic examinations for any diagnostic purpose between June 2017 and December, 2017 in the authors' hospital were examined. Measurements were performed for (MT-CB) and (MT-SE) distances and the results were recorded [MT = The tip of the mastoid process; CB = common carotid artery bifurcation; SE = sternal extremity of the clavicle]. Cervical computed tomography angiography was found in the records of 91 patients in the 6-month period between June 2017 and December 2017. After exclusion criteria were applied, a total of 116 carotid bifurcation levels on the right and left sides were measured in 58 patients. The mean MT-CB distance was 6.29 ±â€Š0.9 cm (range: 2.9-8.4 cm). The mean distance between MT and SE was 15.3 ±â€Š1.7 cm (range: 9.9-19.0 cm). The (MT-CB): (MT-SE) ratios ranged from 29% to 51% with a mean of 41 ±â€Š4.2% (95% CI: 39.88%-42.10%) and a median of 41.1% (P < 0.05) (Kolmogorov-Smirnov test). The distance ratio values did not change significantly according to age and gender (respectively P = 0.341, P = 0.093). These results show that the CB is usually located at two-fifths of the distance from the mastoid tip to the sternal extremity of the clavicle and closer to the mastoid tip.

Surgical Pitfalls in Carotid Endarterectomy: A New Step-By-Step Approach.

Carotid endarterectomy (CEA) is a surgical intervention that may prevent stroke in asymptomatic and symptomatic patients. Our aim was to examine the microsurgical anatomy of carotid artery and other related neurovascular structures to summarize the CEA that is currently applied in ideal conditions. The upper necks of 2 adult cadavers (4 sides) were dissected using ×3 to ×40 magnification. The common carotid artery, external carotid artery (ECA), and internal carotid artery were exposed and examined. The surgical steps of CEA were described using 3-D cadaveric photos and computed tomography angiographic pictures obtained with help of OsiriX imaging software program. Segregating certain neurovascular and muscular structures in the course of CEA significantly increased the exposure. The division of facial vein allowed for internal jugular vein to be mobilized more laterally and dividing the posterior belly of digastric muscle resulted in an additional dorsal exposure of almost 2 cm. Isolating the ansa cervicalis that pulls hypoglossal nerve inferiorly allowed hypoglossal nerve to be released safely medially. The locations of the ECA branches alter depending on their anatomical variations. The hypoglossal nerve, glossopharyngeal nerve, and accessory nerve pierce the fascia of the upper part of the carotid sheath and they are vulnerable to injury because of their distinct courses along the surgical route. Surgical exposure in CEA requires meticulous dissection and detailed knowledge of microsurgical anatomy of the neck region to avoid neurovascular injuries and to determine the necessary surgical maneuvers in cases with neurovascular variations.

Intracranial multiple myeloma may imitate subdural hemorrhage: How to overcome diagnostic limitations and avoid errors in treatment.

BACKGROUND: Although the diagnosis of subdural hematoma is usually straightforward, occasionally it may be erroneous, leading to mistakes in the treatment. For example, leptomeningeal malignancies, even in the absence of bleeding, may clinically and radiologically mimic subdural hemorrhage. OBJECTIVE: To stress the importance of not only intuitive thinking but also in analytic thinking in appropriate and accurate treatment strategies. METHODS AND ILLUSTRATIVE CASE: In this report, the clinical and radiological pitfalls in differentiating malignant leptomeningeal infiltration and subdural hematomas are discussed. A sample case of an intracranial extra-osseous manifestation of a multiple myeloma that is atypical with regard to its location and clinical presentation is presented for illustration. CONCLUSIONS: The variability of intracranial presentation and the wide spectrum of leptomeningeal malignancies necessitate careful preoperative evaluation of the patient's individual history as well as radiological images to avoid misdiagnosis. A clinician who has become familiar with the pitfalls in the differential diagnosis between leptomeningeal infiltrations and subdural hematoma will act more analytically to solve the patient's problems properly and avoid potential complications for the patient.

The Sylvian fissure, cistern and arachnoid membrane.

PURPOSE: The Sylvian (or lateral) fissure is an important structure that has both pathophysiological and microneurosurgical significance. The aims of this review were to revisit the anatomy of the Sylvian fissure and cistern and its overlying arachnoid membrane, and to review its role in the treatment of various surgical pathological lesions. METHODS: For the most part, a PubMed search was used in obtaining English abstracts and full-text references for this article. The criterion for inclusion of an article in the references for this review was that it included materials about the anatomical or the clinical properties of the Sylvian fissure, cistern and arachnoid membrane. The relevant books were also used in obtaining supplementary citations. RESULTS: The review presented the anatomy and disease states associated with the Sylvian fissure. CONCLUSIONS: A good knowledge of the anatomy of the Sylvian fissure, cistern and its associated arachnoid mater is crucial in the proper diagnosis and neurosurgical management of various pathological conditions.

Morphological changes after open lumbar microdiscectomy at 2-year follow-up.

BACKGROUND: It is known that a possible decrease in disc height (DH) and foraminal size after open lumbar microdiscectomy (OLM) may cause pain in the long term. However, there is still insufficient information about the short- or long-term pathoanatomical and morphological effects of microdiscectomy. For example, the exact temporal course of the change in DH is not well known. OBJECTIVE: The purpose of this study was to examine morphological changes in DH and foramen dimensions after OLM. METHODS: In patients who underwent OLM for single-level lumbar disc herniation, MRI scans were obtained before surgery, and at an average of two years after surgery. In addition to DH measurements, foraminal area (FA), foraminal height (FH), superior foraminal width (SFW), and inferior foraminal width (IFW), were measured bilaterally. RESULTS: A postoperative increase in DH was observed at all vertebral levels, with an average of 5.5%. The mean right FHs were 15.3 mm and 15.7 mm before and after surgery, respectively (p= 0.062), while the left FHs were 14.8 mm and 15.8 mm before and after surgery (p= 0.271). The mean right SFW was 5.4 mm before surgery and 5.7 mm after surgery, while the mean right IFW ranged from 3.6 mm to 3.9 mm. The mean left SFW was 4.8 mm before surgery and 5.2 mm after surgery, while the mean left IFW ranged from 3.5 mm to 3.9 mm. Before surgery, the FAs were, on average, 77.1 mm2 and 75.6 mm2 on the right and left sides, respectively. At the 2-year follow-up, the mean FAs were 84.0 mm2 and 80.2 mm2 on the right and left sides, respectively. CONCLUSIONS: Contrary to prevalent belief, in patients who underwent single-level unilateral OLM, we observed that there may be an increase rather than a decrease in DH or foramen size at the 2-year follow-up. Our findings need to be confirmed by studies with larger sample sizes and longer follow-ups.

Factors Affecting Turkish Medical Students' Pursuit of a Career in Neurosurgery: A Single Center Survey Study.

BACKGROUND: Statistics show that over the past 2 decades, even in high-income countries, fewer and fewer students have listed neurosurgery as their top career option. Literature on medical students' pursuit of neurosurgical careers in middle- and low-income countries are scarce. The aim of this research, conducted in Turkey with a middle-income economy, was to contribute insights relevant to medical education and neurosurgery across the world. METHODS: A survey was conducted with a target sample of fourth-year (167 students), fifth-year (169 students), and sixth-year (140 students) medical students (476 in total) from the Medical School at Istanbul Medeniyet University in Turkey. The response rates of the fourth-, fifth-, and sixth-year students were 62% (104/167), 53% (90/169), and 50% (70/140), respectively (in total, 266, including 147 female and 119 male). RESULTS: In terms of the genuine intention, only 2.5% of men and 2.7% of women were committed to specializing in neurosurgery. This study further revealed that possible reasons for these students' low motivation to specialize in neurosurgery were their beliefs that in neurosurgery, the physical and psychological demands were high, and the night shifts were intense, meaning they would not have a social life or spare time for their hobbies; that morbidity/mortality were high; and that financial incentives were insufficient, especially in public institutions. CONCLUSION: Turkish medical students did not rank neurosurgery at the top of their career choices. Possible reasons for this are socioeconomic factors and the inadequate introduction of neurosurgery to medical students.

Microsurgical management of non-neurofibromatosis spinal schwannoma.

INTRODUCTION: The aim of this study is to assess the clinical properties and surgical results of patients diagnosed with spinal schwannomas without neurofibromatosis (NF) properties. PATIENTS AND METHODS: The data obtained from 35 patients who underwent resection of spinal schwannomas were analyzed. All cases with neurofibromas and those with a known diagnosis of NF Type 1 or 2 were excluded. 35 patients underwent surgery for spinal schwannoma at our institution between January 1997 and 2010. The data were gathered retrospectively from medical records and included clinical presentation, tumor location and post-operative complications. All cases were surgically excised, and they were confirmed to be schwannomas by pathologists with histopathological sections in paraffin stained with hematoxylin-eosin. RESULT: We treated 35 (20 males and 15 females) patients with spinal schwannomas. The mean age of the patients was 47.2 (between 13 and 76) years. Of the cases, six schwannomas were located in the cervical spine, four in the thoracic spine, two in cervico-thoracic area, 10 in the thoraco-lumbar area and 13 in the lumbar spine. Two patients had malignant schwannomas that were recurrent. Of the 35 cases, the schwannomas were intradural-extramedullary in 30 cases (86%), intradural-intramedullar in 2 cases (6%), and extradural in 3 cases (9%). CONCLUSION: Spinal schwannomas may occur at any level of the spinal axis and are most frequently intradural-extramedullary. The most common clinical presentation is pain. Most of the spinal schwannomas in non-NF patients can be resected completely without or with minor post-operative deficits. This knowledge may help us to create a strategy for total resection of a spinal schwannomas.

Optimal anatomical angle and distance for drilling in cervical oblique corpectomy: A surgical anatomical study.

Background: One of the difficulties of oblique corpectomy, less discussed in the literature, is the problem of how to achieve an optimum corpectomy. Therefore, this anatomico-radiological study was conducted to shed light on the use of the microscope at an appropriate angle and optimum drill distances in clinical cases undergoing cervical oblique corpectomy surgery. Materials and Methods: We examined the average distance of the diagonal line extending from the medial aspect of the ipsilateral vertebral foramen to the contralateral pedicle in cervical computed tomography -angiography axial scans in four cervical vertebrae, C3, C4, C5, and C6. We also measured the average angle between this diagonal trajectory and the horizontal line, making a total of 712 measurements in 89 patients. Results: We found that horizontal drilling with an average length of 23-26 mm at an acute angle of about 22° -23° is optimal for adequate decompression of the spinal cord in the oblique corpectomy approach. Depending on the patient and the level of the vertebra, the distance and the angle of the horizontal drilling may range from 18 mm to 31 mm and from 15° to 33°, respectively. Conclusions: For an optimum cervical oblique corpectomy that provides adequate spinal cord decompression and maintains spinal stability, it is necessary to operate under a surgical microscope positioned at an acute angle and to know the horizontal drilling distance.