Anteroposterior Combined Surgery of a Rare Massive Epithelioid Hemangioendothelioma at the Cervicothoracic Junction.

Epithelioid hemangioendothelioma is a rare mesenchymal tumor of vascular endothelial origin. Non-soft tissue epithelioid hemangioendothelioma can also be seen in different organs. Although chemotherapy has been used in some patients, complete surgical removal of the tumor tissue has proven to be the most durable solution. A 15-year-old female patient was admitted to our institution with right arm and neck pain. The patient complained of numbness and weakness in the right hand. Computerized tomography indicated an expansile lesion exhibiting osteolytic features located predominantly on the right side of the corpus, pedicle, lamina, and lateral processes of the C7-T1 vertebra. The patient underwent a surgical procedure involving the application of a bilateral C4-5-6 lateral mass screw, left C7-T1 pedicle screw, and bilateral T2-3 pedicle screw and fusion. The complete residual neoplasm was surgically removed during the procedure. Due to the rarity of epithelioid hemangioendothelioma, the existing literature on this topic is confined to case reports, supplemented by a small number of retrospective descriptive case series that aimed to improve our understanding of the clinical, pathological, and molecular features of the condition, as well as to guide potential treatment strategies.

The Necessity of Extensive Decompression for Spinal Epidural Hematoma: A Case Report and Literature Review.

Spinal epidural hematomas (SEHs)are space-occupying lesions that exert pressure on the spinal cord by rapidly accumulating blood between the dura and bone or ligament components. The annual incidence of spontaneous epidural hematoma is estimated to be one in one million. The predominant symptoms are back pain or neurological impairment, including sensory, motor, or autonomic dysfunction of the limbs below the hematoma level. Depending on the level and size of the hematoma and the affected cord, they cause neurological deficits. Neurological deficits are often reversible if diagnosed and treated early with surgical decompression. However, neurological deficits can become permanent if the patient is not operated on timely, and paraplegia or quadriplegia may occur. A 53-year-old man presented to our emergency department with acute-onset back pain and 36-hour-long, rapidly progressive paraparesis of both legs. On T1- and T2-weighted MRI scans, a hyperacute SEH was found as iso/hyperintense and hyperintense, respectively. Immediate decompressive laminectomy from T10 to L2 and hematoma evacuation were performed. It was challenging to remove the hematoma due to its firm consistency. Before performing a bilateral total laminectomy at five levels, the posterior spine was stabilized between T10 and L3 using transpedicular screws. Within 24 hours, the motor function of the lower limbs increased considerably. The patient could sit on a chair because of posterior stability. In addition to the importance of early diagnosis using imaging techniques, planning the extension of SEH surgery is crucial for the patient's postoperative neurological recovery.

Modafinil attenuates the neuroinflammatory response after experimental traumatic brain injury.

BACKGROUND: Modafinil has been proven to exert anti-inflammatory, anti-oxidative and neuroprotective effects on numerous neurological disorders. However, its effects after traumatic brain injury (TBI) have not been yet explored. The aim of this study was to explore if Modafinil can attenuate the neuroinflammatory phase of TBI and clarify the possible underlying mechanisms. METHODS: A weight drop model was used to induce experimental TBI on 30 Wistar albino rats. The treatment group received Modafinil on the day of the trauma and the following 5 days. Garcia Test was used to assess for neurological status and histopathological examination along with biochemical analysis of NSE, S-100B, CASP3, and TBARS levels were performed. RESULTS: Rats treated with Modafinil after the trauma had a statistically significant higher Garcia Test Score (P<0.001) and presented with increased evidence of anti-inflammatory and neuroprotective effect (P<0.05, P=0.005). Decreased levels of all biochemical parameters with NSE, CASP3, and TBARS having statistical significance was observed (P<0.05). CONCLUSIONS: The findings of this paper support the notion that a psychoactive drug Modafinil, traditionally used for sleep disorders and also known as a cognitive enhancer may prove beneficial in decreasing mortality and morbidity after TBI through anti-inflammatory, anti-oxidative and neuroprotective effects.

Percutaneous endoscopic translaminar approach in a patient with pedicle screw malposition and cement leakage.

We present a 79-year-old female patient who had L2-5 dynamic stabilization with cement (Polymethylmethacrylate) injection 6 weeks prior. Due to post-operative right radicular pain, a lumbar CT was scheduled in which a malposition of the right L4 screw and cement leakage was observed. Via a percutaneous translaminar endoscopic approach the leaked cement was removed and the portion of the screw in contact with the nerve root was drilled. With this minimal-invasive procedure, the patient was relieved of her radicular pain.

Temporary 6TH cranial nerve paralysis after accidental durotomy in endoscopic disc surgery.

We present a unique case of 6th nerve palsy following accidental durotomy in endoscopic lumbar spine surgery, which has not been reported in the literature before. A 72- year-old female patient was admitted to our outpatient clinic complaining of right leg pain for 6 months. A 4/5 motor paresis was observed on her right toe with a positive Lasegue test at 45°. On her magnetic resonance imaging (MRI), a L5-S1 disc herniation was detected. The patient was planned for percutaneous endoscopic interlaminar disc surgery. The extruded disc was adherent to the dura. During removal, a dural tear was observed. She was relieved of her right leg pain immediately after surgery, but after 30 min postoperatively, she complained of double vision with left abducens nerve paralysis. On cranial MRI, no abnormality could be observed. Intravenous fluids were administered and the paralysis resolved on the postoperative 24th hour. The patient was discharged from the hospital and did not show any complaints on her follow-ups. A 6th nerve palsy can be caused due to alterations of intracranial pressure or mechanic injury. We believe that the durotomy following removing of the disc fragment caused a rapid drainage of CSF, leading to intracranial hypotension and injury of the abducens nerve. Intracranial pressure should be monitored perioperatively and brisk deteriorations has to result in immediate finishing of the surgery to avoid further secondary damage.

Modified Kickstand Rod Technique for the Correction of Adult Idiopathic Scoliosis.

Adult idiopathic scoliosis (ADIS) is the delayed form of adolescent idiopathic scoliosis (AIS) which is defined as a three-dimensional deformity with a lateral curvature of more than 10° in adults with prior history of AIS. Surgery is necessary for patients with symptoms of chronic pain, neuromotor deficits and cardiopulmonary problems with a Cobb angle exceeding 45°. In untreated patients, AIS may lead to ADIS which can cause serious problems like osteoarthritis, progressive deformity and spinal stenosis. In recent years, the kickstand rod technique has been introduced in addition to posterior transpedicular stabilization. A kickstand rod is an additional rod which is placed on a supporting iliac screw which is placed on the superior lateral edge of the ilium on the concave side of the deformity (or in other words on the ipsilateral side of the trunk shift) and is connected with a domino connector to the thoracolumbar junction. The rod is then distracted with the screw nuts locked on the contralateral side to achieve coronal correction. The classic kickstand works as a an additional aid to keep the spine in place during maneuvering. We established a modified kickstand rod technique where we put the rod on the concave side and apply compression between the rod on the screw heads and the kickstand to bring the concavity to the midline. The kickstand was used as a temporary tool like a lever to push the spine medially with compression. We believe that our technique can be a useful alternative for correction of coronal imbalance besides the classic one.

Effects of pirfenidone on experimental head injury in rats.

Traumatic brain injury (TBI) continues to be a significant public healthcare concern. Neuroinflammation that occurs in the secondary phase of TBI leads to cognitive and physical dysfunction. A number of therapeutic modalities have been evaluated in an attempt to find a suitable treatment. The only drug approved for the treatment of idiopathic pulmonary fibrosis, pirfenidone, has been evaluated for its antifibrotic, anti-inflammatory, and anti-oxidant properties for various disorders, but this is the first study to examine its effects in an experimental TBI model. Twenty-four Wistar rats were randomly divided into three groups: control, trauma, and pirfenidone. The two latter groups underwent experimental diffuse cortical injury mimicking TBI. Neurological assessment was performed using the Garcia test, histological analysis was performed to examine neuroprotective and anti-inflammatory effects, and biochemical analyses of neuron-specific enolase (NSE), S-100B, caspase-3, and thiobarbituric acid reactive substances were performed. The pirfenidone group had a better Garcia test score (P=0.001), an increased anti-inflammatory effect (P<0.001), and an enhanced neuroprotective effect (P=0.007) along with decreased NSE, S100B, and TBARS levels compared to the trauma group. However, pirfenidone did not show a beneficial effect on caspase-3 levels. Pirfenidone may help decrease mortality and morbidity rates after TBI through its anti-inflammatory and antioxidant effects.

Comparison of direct costs of percutaneous full-endoscopic interlaminar lumbar discectomy and microdiscectomy: Results from Turkey.

BACKGROUND AND PURPOSE: Microdiscectomy (MD) is a stan-dard technique for the surgical treatment of lumbar disc herniation (LDH). Uniportal percutaneous full-endoscopic in-terlaminar lumbar discectomy (PELD) is another surgical op-tion that has become popular owing to reports of shorter hos-pitalization and earlier functional recovery. There are very few articles analyzing the total costs of these two techniques. The purpose of this study was to compare total hospital costs among microdiscectomy (MD) and uniportal percutaneous full-endoscopic interlaminar lumbar discectomy (PELD). METHODS: Forty patients aged between 22-70 years who underwent PELD or MD with different anesthesia techniques were divided into four groups: (i) PELD-local anesthesia (PELD-Local) (n=10), (ii) PELD-general anesthesia (PELD-General) (n=10), (iii) MD-spinal anesthesia (MD-Spinal) (n=10), (iv) MD-general anesthesia (MD-General) (n=10). Health care costs were defined as the sum of direct costs. Data were then analyzed based on anesthetic modality to produce a direct cost evaluation. Direct costs were compared statistically between MD and PELD groups. RESULTS: The sum of total costs was $1,249.50 in the PELD-Local group, $1,741.50 in the PELD-General group, $2,015.60 in the MD-Spinal group, and $2,348.70 in the MD-General group. The sum of total costs was higher in the MD-Spinal and MD-General groups than in the PELD-Local and PELD-General groups. The costs of surgical operation, surgical equipment, anesthesia (anesthetist's costs), hospital stay, anesthetic drugs and materials, laboratory wor-kup, nur-sing care, and two main groups (PELD-MD) me-dication diffe-red significantly among the two main groups (PELD-MD) (p<0.01). CONCLUSION: This study demonstrated that PELD is less costly than MD.

Perineal anesthesia following interlaminar endoscopic disc surgery.

Perineal anesthesia is defined as the loss of sensation to the area of buttocks, perianal space and thighs. It is often seen in cauda equina syndrome as a collection of acute symptoms mostly occurring secondary to a large disc herniations leading to neuropathy of multiple lumbar and sacral nerve roots. We present 30 years- old male patient who was admitted with sever left leg pain for over a month. On neurological examination a 3/5 plantarflexion paresis was observed on the left with hypoesthesia concordant to the S1 dermatome. A lumbar MRI showed a broad left L5-S1 disc herniation was detected. The patient underwent interlaminar endoscopic disc surgery and postoperatively, was relieved of his pain and a slightly improvement of his paresis was seen. On the first week follow-up he complained of anesthesia of his buttocks when sitting. On follow-up MRI, the disc was removed completely and no further pathologies could be seen. The patient continued physical therapy and on the 8th week postoperatively his paresis and perineal anesthesia resolved completely. Perineal anesthesia following endoscopic disc surgery was a complication we never have experienced at out clinic. Even when searching through medical databases we have not seen any reports in the literature in that way.

Radiological evaluation of the localization of sympathetic ganglia in the cervical region.

PURPOSE: To determine local variations of cervical sympathetic ganglia (CSG) according to vertebral levels on preoperative neck magnetic resonance imaging (MRI) by designating carotid artery (CA) as the standard landmark at the center, in attempts to prevent injury to CSG in the anterior-anterolateral approaches performed in the cervical spinal region. MATERIALS AND METHODS: The retrospective study reviewed neck MRI images of 281 patients, of which the images of 231 patients were excluded from the study based on the exclusion criteria. As a result, the MRI images of the remaining 50 patients were included in the study. The circumference of carotid artery (CA) was divided into eight equal zones with CA defined as the standard landmark at the center. High-risk zones were determined based on the anterior-anterolateral approaches. RESULTS: At C1 level, a superior ganglion was located on the right side in 32 (64%) and on the left side in 30 (60%) patients. At this level, it was most commonly located in Zone 6. Middle ganglion was observed most frequently at C3 level, which was detected on the right side in 17 (34%) and on the left side in 17 (34%) patients. At this level, it was most commonly located in Zone 2. CONCLUSION: Variations in the localizations of superior and middle cervical ganglia should be taken into consideration prior to surgical procedures planned for this region. This study sheds light on high-risk zones in the surgical site and could guide surgeons to better understand the location of cervical sympathetic ganglia before surgical planning.

Treatment of Multiple Junctional Vertebra Fractures in a Single Case.

We present a unique case of multiple junctional vertebra fractures in a single patient requiring surgical intervention, the variety of which has not yet been reported in the literature. A 15-year old female was admitted to our emergency department after a suicide attempt from jumping from the window of a five-floor building. On admission her general status was critical, Glasgow Coma Scale (GCS) was 6, and on painful stimuli she was able to move all four extremities. On her spinal CT, a C1 right arcus fracture, a C7 corpus fracture, an L3 and L5 burst fracture and a right sacrum fracture were detected. The patient also suffered from pneumothorax, pleural effusion and pulmonary contusions. After she was stable and extubated, she did not show any motor or sensory deficits. As the patient still had some pleural effusion and pulmonary contusions, posterior approaches were avoided at first and a C6-T1 anterior stabilization with mini plate-screws was performed. After her pulmonary problems resolved, a series of spinal instrumentation surgeries were performed over the following weeks. A case like this in which multiple traumatic junctional fractures were treated with different surgical techniques has not been reported in the literature before. It is important to emphasize if and when surgical intervention is needed. A multidisciplinary assessment of trauma surgeons, neurosurgeons and anesthesiologists is vital for forming a further treatment plan.

Minimally Invasive Far-Lateral Microdiscectomy: A New Retractor for Far-Lateral Lumbar Disc Surgery.

Background To date, a number of approaches have been described for far-lateral disc surgery, including midline, paramedian, and intertransverse approaches. These approaches pose challenges for surgeons due to the difficulty in retraction caused by the anatomy of the foramen. We designed a retractor suitable for the three-dimensional anatomical structure of the foramen. In this study, we aimed to evaluate the surgical outcomes of the patients who were operated on using this retractor in our clinic. Methods  The retrospective study included patients who were operated on due to far-lateral disc herniation using the retractor designed in our clinic between February 2013 and December 2018. Results  The study included 11 (64.7%) women and 6 (35.3%) men, with a mean age of 56 years (range: 42-70 years). The mean operative time was 49 minutes (range: 40-70 minutes), the mean estimated blood loss was 42 mL (range: 25-60 mL), and the mean follow-up period was 22.6 months (range: 13-48 months). No complication occurred in any patient. A minimally invasive discectomy was performed via the paramedian approach in each patient. The patients were evaluated using the visual analog scale (VAS) for radicular pain, Oswestry Disability Index (ODI), 36-Item Short Form Survey (SF-36), and the modified MacNab criteria. Conclusion  The retractor developed in our study provided numerous benefits during the surgical procedure as it led to minimal blood loss and reduced operative times by avoiding bone resection in extraforaminal discs and requiring minimal bone resection in foraminal discs.

Kyphosis After Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations.

Thoracolumbar fractures change the biomechanics of the spine. Load distribution causes kyphosis by the time. Treatment of posttraumatic kyphosis is still controversial. We reviewed the literature between 2010 and 2020 using a search with keywords "thoracolumbar fracture and kyphosis." We removed osteoporotic fractures, ankylosing spondylitis fractures, non-English language papers, case reports, and low-quality case series. Up-to-date information on posttraumatic kyphosis management was reviewed to reach an agreement in a consensus meeting of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. The first meeting was conducted in Peshawar in December 2019 with WFNS Spine Committee members' presence and participation. The second meeting was a virtual meeting via the internet on June 12, 2020. We utilized the Delphi method to administer the questionnaire to preserve a high degree of validity. We summarized 42 papers on posttraumatic kyphosis. Surgical treatment of thoracolumbar kyphosis due to unstable burst fractures can be done via a posterior only approach. Less blood loss and reduced surgery time are the main advantages of posterior surgery. Kyphosis angle for surgical decision and fusion levels are controversial. However, global sagittal balance should be taken into consideration for the segment that has to be included. Adding an intermediate screw at the fractured level strengthens the construct.

Hemipartial Laminectomy and Bilateral Flavectomy Technique With Unilateral Approach in Patients With Cervical Spinal Stenosis Due to Ligamentum Flavum Hypertrophy: A Technique Note.

The aim of this procedure is to widen the spinal canal by using minimally invasive techniques to do hemipartial laminectomy and bilateral flavectomy in patients with cervical spinal stenosis due to ligamentum flavum hypertrophy. A 66-year-old man presented with increasing neck and right shoulder pain for one year to Koç University Hospital. He reported a three-month history of numbness in his hands. The Japanese Orthopedic Association (JOA) and Visual Analogue Scale (VAS) scores were 15 and 8, respectively. Preoperative magnetic resonance imaging (MRI) revealed spinal canal stenosis at the C3-4 level secondary to ligamentum flavum hypertrophy. Hemi-partial laminectomy at the C3 level, flavectomy, and bilateral decompression were performed using the right unilateral approach. The patient's complaints of symptoms considerably decreased three months later. The VAS and JOA scores were 2 and 16, respectively. This minimally invasive approach can be an alternative to classic laminectomy in patients who have radiculopathy and myelopathy due to posterior origin spinal stenosis in order to safely resolve pain and neurologic dysfunction.

A New Technique That Percutaneous Endoscopic Decompression and Vertebroplasty in a Patient With Osteoporotic Vertebral Fracture: A Case Report.

STUDY DESIGN: Technique note. OBJECTIVE: To evaluate the feasibility of endoscopy in various spinal pathologies. SUMMARY OF BACKGROUND DATA: Osteoporotic vertebral fractures are a common pathology in the elderly. These fractures are often accompanied by serious complications such as neurological deficits due to the compression of the spinal cord or nerve roots. METHODS: A 78-year-old female patient presented to our hospital with a severe pain in her left leg and back. Lumbar magnetic resonance imaging and computed tomography scan revealed an osteoporotic L3 burst fracture compressing the left L3 nerve root. A minimally invasive translaminar endoscopic approach was used to remove the fractured fragment and cement was injected into the L3 vertebra. The patient was mobilized the same evening and was relieved of her pain. CONCLUSION: Minimally invasive endoscopy is a safe and effective alternative to conventional major decompression with or without posterior stabilization, particularly in elderly patients with serious comorbidities. LEVEL OF EVIDENCE: 4.

Percutaneous Endoscopic Interlaminar Decompression of Hypervascular Spinal Metastases.

BACKGROUND: Percutaneous endoscopic surgery is a common technique used for the treatment of disk herniation and spinal stenosis. In this report, we present a patient who underwent percutaneous endoscopic decompression due to spinal metastasis. CASE DESCRIPTION: A 72-year-old female patient with a known diagnosis of lung cancer presented to our clinic with a 10-day history of severe pain in the left leg and a 5-day history of muscle weakness in the left thigh. The patient had a history of multiple organ metastasis and multiple spinal metastasis. On neurologic examination, left hip flexion and extension were graded 2/5. Radiologic workup revealed compression on the left L3 nerve root caused by vertebral metastasis. The patient was planned for a percutaneous full-endoscopic interlaminar decompression due to her clinical condition. The tumor surrounding the left L3 nerve root was removed via endoscopic punch, which resulted in rapid relief of her back pain postoperatively. Adjunct physical therapy was recommended after discharge. CONCLUSIONS: Percutaneous full-endoscopic interlaminar decompression can be an alternative minimally invasive treatment option in selected patients with radicular pain and neurologic deficit caused by spinal metastasis.

Percutaneous Full-Endoscopic Removal of Lumbar Intradural Extramedullary Tumor via Translaminar Approach.

BACKGROUND: Despite the fact that technologic advances and surgical experience expand the use of endoscope in spinal surgery, there are few reports on its application in the management of spinal tumors. We present a case report of intradural extramedullary tumor excision with the percutaneous full endoscopic translaminar approach. CASE DESCRIPTION: A 67-year-old male presented to our clinic with lumbar, left thigh pain and paresthesia in both thighs. Preoperative magnetic resonance imaging revealed a contrast-enhanced intradural extramedullary mass with benign characteristics on L1 with the preliminary diagnosis of meningioma. The percutaneous translaminar endoscopic approach was planned to remove the intradural extramedullary tumor from a 7-mm skin incision. Surgery was planned in 4 stages: 1) exposure of the dura by opening a window on the lamina, 2) opening and expanding of the dura, 3) exposure of all sides of the tumor, and 4) excision of the tumor and hemostasis. Closing the dura and ending the surgery. CONCLUSIONS: This report supports that full endoscopic spinal intradural extramedullary mass excision may give good results in selected cases and in experienced hands.

A Novel Modular Dynamic Stabilization System for the Treatment of Degenerative Spinal Pathologies.

AIM: To show the preliminary clinical results of the Orthrus modular dynamic stabilization system that is a new instrumentation system intended for degenerative diseases of the lumbar spine. MATERIAL AND METHODS: The system utilizes two different types of screws that can be used in conjunction with different types of rods such as titanium, carbon fiber or PEEK. The first type of screw is a double headed screw to interconnect to the upper and lower level with independent rods. The second type of screw is a sliding screw to be used on a immovable vertebrae that allows movement in two planes on the tip. RESULTS: The system has been used on 36 patients with pathology varying from degenerative disc disease to degenerative lumbar scoliosis. Satisfactory results have been obtained in a all 36 patients in the 12-month follow-up period. CONCLUSION: The Orthrus dynamic system shows better clinical results than the available dynamic systems on the market. It also proves to provide similar fusion with considerably less postoperative morbidity which makes it a better method to treat adult degenerative spine diseases for carefully chosen patients.

How to Reduce Stress on the Pedicle Screws in Thoracic Spine? Importance of Screw Trajectory: A Finite Element Analysis.

AIM: To investigate the biomechanical comparison of thoracic transpedicular screw trajectories on the sagittal plane. MATERIAL AND METHODS: A three-dimensional, non-linear finite element analysis (FEA) model of T8 through T9 was used. Anatomic trajectory (AT) and Straightforward trajectory (ST) models of the transpedicular screws were used in the intact FEA model. The von-Mises stress and range of motion (ROM) of the transpedicular screws were evaluated. RESULTS: The difference in ROM between both techniques was negligible. In lateral bending and axial rotation, FEA showed decrease in stress by 25% and 8%, respectively, when pedicle screws were placed using AT. CONCLUSION: AT decreased the von-Mises stress of the pedicle screws, thereby reducing the rates of screw breakage and fatigue risks. In addition, we believe that AT could protect against screw loosening because the von-Mises stress of the internal fixation was scattered.

Can Right-Handed Surgeons Insert Upper Thoracic Pedicle Screws in much Comfortable Position? Right-Handedness Problem on the Left Side.

OBJECTIVE: Thoracic pedicles have special and specific properties. In particular, upper thoracic pedicles are positioned in craniocaudal plane. Therefore, manipulation of thoracic pedicle screws on the left side is difficult for right-handed surgeons. We recommend a new position to insert thoracic pedicle screw that will be much comfortable for spine surgeons. METHODS: We retrospectively reviewed 33 patients who underwent upper thoracic pedicle screw instrumentation. In 15 patients, a total of 110 thoracic pedicle screws were inserted to the upper thoracic spine (T1-6) with classical position (anesthesiologist and monitor were placed near to patient's head. Surgeons were standing classically near to patient's body while patients were lying in prone position). In 18 patients, a total of 88 thoracic pedicle screws were inserted to the upper thoracic spine with the new standing position-surgeons stand by the head of the patient and the anesthesia monitor laterally and under patient's belt level. All the operations performed by the same senior spine surgeons with the help of C-arm. Postoperative computed tomography scans were obtained to assess the screw placement. The screw malposition and pedicle wall violations were divided and evaluated separately. Cortical penetration were measured and graded at either : 1-2 mm penetration, 2-4 mm penetration and >4 mm penetration. RESULTS: Total 198 screws were inserted with two different standing positions. Of 198 screws 110 were in the classical positioning group and 88 were in the new positioning group. Incorrect screw placement was found in 33 screws (16.6%). The difference between total screw malposition by both standing positions were found to be statistically significant (p=0.011). The difference between total pedicle wall violations by both standing positions were found to be statistically significant (p=0.003). CONCLUSION: Right-handedness is a problem during the upper thoracic pedicle screw placement on the left side. Changing the surgeon's position standing near to patient's head could provide a much comfortable position to orient the craniocaudal plane of the thoracic pedicles.