Effect of two-level decompressive procedures on the biomechanics of the lumbo-sacral spine: an ex vivo study.

Hemilaminectomy and laminectomy are decompressive procedures commonly used in case of lumbar spinal stenosis, which involve the removal of the posterior elements of the spine. These procedures may compromise the stability of the spine segment and create critical strains in the intervertebral discs. Thus, this study aimed to investigate if decompressive procedures could alter the biomechanics of the lumbar spine. The focus was on the changes in the range of motion and strain distribution of the discs after two-level hemilaminectomy and laminectomy. Twelve L2-S1 cadaver specimens were prepared and mechanically tested in flexion, extension and both left and right lateral bending, in the intact condition, after a two-level hemilaminectomy on L4 and L5 vertebrae, and a full laminectomy. The range of motion (ROM) of the entire segment was assessed in all the conditions and loading configurations. In addition, Digital Image Correlation was used to measure the strain distribution on the surface of each specimen during the mechanical tests, focusing on the disc between the two decompressed vertebrae and in the two adjacent discs. Hemilaminectomy did not significantly affect the ROM, nor the strain on the discs. Laminectomy significantly increased the ROM in flexion, compared to the intact state. Laminectomy significantly increased the tensile strains on both L3-L4 and L4-L5 disc (p = 0.028 and p = 0.014) in ipsilateral bending, and the compressive strains on L4-L5 intervertebral disc, in both ipsilateral and contralateral bending (p = 0.014 and p = 0.0066), with respect to the intact condition. In conclusion, this study found out that hemilaminectomy did not significantly impact the biomechanics of the lumbar spine. Conversely, after the full laminectomy, flexion significantly increased the range of motion and lateral bending was the most critical configuration for largest principal strain.

Does Minimally Invasive Hemilaminectomy for Intradural Extramedullary Tumor Resection Prevent Postlaminectomy Kyphosis or Lordosis Loss?

BACKGROUND: Minimally invasive hemilaminectomy is a safe and effective alternative to open laminectomy for treating intradural extramedullary tumors. There are no reports of postoperative kyphosis after this approach. This study aims to determine whether performing minimally invasive spine surgery hemilaminectomy for intradural extramedullary tumors can prevent the development of postlaminectomy kyphosis (PLK) or lordosis loss. MATERIAL AND METHODS: Sixty-five patients with spinal intradural extramedullary tumors who underwent minimally invasive hemilaminectomy surgery and complete pre and postoperative radiologic imaging were included. The effect of the surgical approach on the spinal sagittal axis was assessed by comparing pre- versus postoperative segmental and local Cobb angles at different spinal levels, considering anatomical localization (cervical, thoracic, lumbar, and transition segments) and functional features (mobile, semi-rigid, and transition segments), as well as the extent of the surgical approach (1, 2, or 3 levels) and follow-up. RESULTS: None of the patients had an increase in thoracic kyphosis nor a loss of cervical or lumbar lordosis greater than or equal to 10° after undergoing the minimally invasive spine surgery hemilaminectomy approach. More than 5° of increase in kyphosis was detected on 7.4% and 11.1%, for the segmental and the local angles, respectively; meanwhile, for patients with loss of lordosis, this deviation was detected in 5.3%, for both angles. The occurrence of PLK was more common than that of lordosis loss, but mainly manifested in postoperative angle impairment of less than 5°. No significant differences were evidenced, considering the approach length. CONCLUSIONS: Hemilaminectomy represents a promising approach for preventing PLK and postlaminectomy lordosis loss following intradural extramedullary tumor resection.

A Rare Case of a Spontaneous Thoracic Epidural Hematoma in a Young Male Weightlifter.

Spontaneous spinal epidural hematoma (SSEH) is the accumulation of blood in the epidural space of the spinal cord. Acute SSEH is a rare phenomenon that presents with a wide variety of neurologic symptoms and most often is a surgical emergency. We present a previously healthy 34-year-old male with sudden onset progressive weakness and tingling in the right lower extremity that progressed to the left lower extremity while bench pressing weights, resulting in complete lower extremity paralysis. Magnetic resonance imaging (MRI) revealed a 3.0 cm extradural mass centered in the dorsal and left lateral canal. After a T1-T4 hemilaminectomy was performed which was followed by inpatient rehabilitation, the patient had a favorable outcome improving from The American Spinal Injury Association Impairment Scale (AIS) grade A, complete impairment, to AIS grade C, incomplete impairment on discharge. Initially, the patient had complete motor and sensory paralysis below the level of T4, and upon discharge, the patient was able to attain modified independence in activities of daily living, mobility, and transfer. Due to the lack of risk factors for SSEH in this patient, the etiology is most likely related to the Valsalva maneuver while weightlifting. Lesions in the thoracic region with rapid progression of neurologic symptoms are indicators of poor prognosis, so this case highlights the importance of prompt recognition and intervention for improved outcomes to prevent devastating neurologic defects.

Unilateral hemilaminectomy vs. laminoplasty for the resection of spinal schwannomas: an analysis of 100 patients.

Objective: Spinal schwannomas are the most common intradural extramedullary tumors, and their complete removal is recommended to avoid tumor recurrence. Although laminoplasty provides a sufficient window for tumor resection, this approach may increase tissue trauma and cause postoperative instability compared with unilateral hemilaminectomy. This study aimed to compare the efficacy and clinical outcomes of the two approaches. Materials and methods: We included 100 consecutive patients who underwent unilateral hemilaminectomy or laminoplasty for resection of spinal schwannomas between January 2015 and February 2023. The patients' baseline characteristics, including sex, age, tumor location, percentage of tumor occupying the intradural space, operative time, postoperative length of hospital stay, intraoperative bleeding volume, visual analog scale score, and neurologic results, were retrospectively analyzed. Results: Hemilaminectomy patients who underwent unilateral hemilaminectomy had smaller intraoperative bleeding (p = 0.020) volume, shorter operative time (p = 0.012), and shorter postoperative length of hospital stay (p = 0.044). The mean VAS scores at the last follow-up were similar between the two groups (p = 0.658). Although the postoperative McCormick and Karnofsky Performance scores were not significantly different between the laminoplasty and unilateral hemilaminectomy groups (p = 0.687 and p = 0.649, respectively), there was a statistically significant improvement based on postoperative neurological results compared to preoperative neurological results for both groups. The incidence of postoperative complications was 5% and 11.7% in the unilateral hemilaminectomy and laminoplasty groups, respectively (p = 0.308). Conclusions: For spinal schwannoma resection, unilateral hemilaminectomy has more advantages than laminoplasty, including a shorter postoperative hospital stay, faster procedure, and less intraoperative blood loss while achieving the same desired result.

Retrospective comparison between low-volume high-concentration and high-volume low-concentration levobupivacaine for bilateral erector spinae plane block in dogs undergoing hemilaminectomy.

OBJECTIVE: To compare the analgesic effect of a bilateral ultrasound-guided erector spinae plane block (ESPB) in dogs undergoing hemilaminectomy using either a low-volume high-concentration (LV-HC) or a high-volume low-concentration (HV-LC) local anaesthetic solution. STUDY DESIGN: Retrospective observational equivalence trial. ANIMALS: A total of 391 client-owned dogs undergoing hemilaminectomy. METHODS: Dogs were assigned to group LV-HC or HV-LC depending on whether 0.2-0.25% levobupivacaine (0.4-0.5 mL kg-1) or 0.125-0.15% levobupivacaine (0.8-1 mL kg-1) was used to perform the ESPB, respectively. The number of dogs in which intraoperative rescue fentanyl boluses were administered, the total dose of fentanyl administered, the overall methadone consumption during the first 24 hours postoperatively and anaesthetic complications were recorded. Univariate and multivariate statistical analyses were performed considering p < 0.05 significant. RESULTS: A total of 248 and 143 dogs were assigned to groups LV-HC and HV-LC, respectively. In group HV-LC, the number of dogs requiring fentanyl intraoperatively (64.3%) was higher (p = 0.0001) than that in group LV-HC (43.5%). The overall intraoperative fentanyl consumption was higher in group HV-LC between the first skin incision and the end of the lamina drilling (p = 0.028). According to the regression analysis, the group allocation was the best variable to predict the intraoperative fentanyl consumption (p < 0.001). Antimuscarinic drugs were administered more frequently in group LV-HC (p < 0.02). However, the prevalence of hypotension and other pharmacological cardiovascular interventions did not differ between groups. No differences in methadone consumption during the first 24 hours postoperatively were found between the groups. CONCLUSIONSAND CLINICAL RELEVANCE: When performing a bilateral ESPB in dogs undergoing hemilaminectomy, compared with HV-LC, the use of LV-HC local anaesthetic solution reduces the intraoperative fentanyl consumption without affecting the postoperative methadone requirement.

Evaluation of anatomic landmarks to increase precision performing a mini-hemilaminectomy-an ex vivo study in dogs.

The mini-hemilaminectomy is a frequently used surgical technique for decompressive disk surgery on dogs. The aim of the study was to assess landmarks in the canine thoracolumbar spine to perform a mini-hemilaminectomy, with the aim of achieving optimal exposure of the ventral aspect of the vertebral canal. We hypothesized that the accessory process is a useful landmark for the identification of the level of the vertebral canal floor (VCF) and for decreasing surgical time. To define the level of the VCF, different landmarks and their distance to the VCF from computed tomography images of 40 mature chondrodystrophic dogs were evaluated in the first part of the study. To test the predefined landmarks, a cadaveric experiment was subsequently performed in the second part of the study. An experienced surgeon and a second-year surgical resident performed mini-hemilaminectomies as precisely as possible, with and without using the landmark values. Surgery time, precision of the mini-hemilaminectomy, and iatrogenic damage of the spinal nerve roots were compared between the two groups. Based on the results in the first part of the study, the distance from the dorsal border of the accessory process to the VCF (DBAP-VCF) was chosen as a landmark due to the good intra- (0.96) and interobserver (0.83) agreement. However, the distance is highly variable between breeds. In the second part of the study, using the DBAP-VCF landmark value did not influence the surgery time in both surgeons (p = 0.467, p > 0.99). An improved accuracy of the VCF was seen for the surgical resident with limited experience (p = 0.014), but not for the experienced surgeon (p = 0.926). For both surgeons, the spinal nerve roots were injured in 20% of the cases unrelated to the use of landmark values. In conclusion, this study suggests that the DBAP-VCF has been described as a breed-specific landmark that can be determined in CT with good agreement. Using the previously evaluated landmark values can help improve precision in decompressive spinal surgery for a surgeon with limited experience without prolonging surgical time.

The use of a minimally invasive integrated endoscopic system to perform hemilaminectomies in chondrodystrophic dogs with thoracolumbar intervertebral disc extrusions.

Introduction: The objective was to evaluate the use of a minimally invasive surgical (MIS) approach to perform hemilaminectomies in chondrodystrophic dogs with thoracolumbar intervertebral disc extrusions (IVDE). Additionally, we aimed to evaluate the degree of soft tissue trauma using the endoscopic procedure compared to the standard open approach. Methods: Eight client-owned dogs presented to the Colorado State University Veterinary Teaching Hospital with acute onset thoracolumbar IVDE were included in this study. This was a prospective, randomized case-series. Patients were assigned to undergo an endoscopic (group 1; n = 4) or a standard open approach (group 2; n = 4) for a hemilaminectomy. A post-operative MRI was performed in all cases. Results: Conversion to an open approach was not necessary for any case in group 1. All cases had adequate spinal cord decompression on post-operative MRI. There was no significant difference in soft tissue changes noted on post-operative MRI between the two groups. Discussion: The MIS approach to hemilaminectomies in chondrodystrophic dogs with thoracolumbar IVDE can successfully be performed to decompress the neural tissue and appears to lead to similar clinical outcomes in the early postoperative period compared to the standard open approach. Larger studies are needed to determine the potential advantages of the MIS technique compared to the standard open approach in veterinary medicine.

Intraspinal Extradural Degenerative Cervical Cyst Treated by Anterior Cervical Discectomy and Fusion: A Surgical Alternative to the Posterior Approach, about One Case.

Introduction: Intraspinal extradural arthrosynovial cysts, which belong to the spectrum of degenerative spinal diseases are mainly located at lumbar level and their location at cervical level joint is therefore unusual. The most common surgical approach for symptomatic arthrosynovial cervical cyst remains a direct resection of the cyst by a cervical hemilaminectomy with or without a posterior arthrodesis. However, another surgical approach may also be discussed when considering the cyst as a result of a local spinal instability or hypermobility. Case Report: We report in this work the case of a patient with cervical radiculopathy due to intraspinal extradural compressive arthrosynovial cervical cyst which was treated by anterior discectomy and fusion without direct resection of the cyst. The post-operative radiological control performed at 3 months showed a complete regression of the cyst with a patient pain-free. To the best of our knowledge, this is the first case of intraspinal cervical degenerative cyst at C7-T1 level treated by anterior approach and fusion without direct cyst resection. Conclusion: For the treatment of a joint spinal cervical cyst, the anterior approach is a relevant option that gives the advantages to respect the posterior cervical muscles and articular structures.

[Application of microchannel technique in minimally invasive resection of cervical intraspinal tumors].

OBJECTIVE: To explore the application and key points of microchannel approaches in resection of cervical intraspinal tumors. METHODS: A retrospective analysis was performed on 51 cases of cervical spinal canal tumors from February 2017 to March 2020. Among them, 5 cases were located epidural space, 6 cases were located epidural and subdural space, and 40 cases were located under the subdural extramedullary space(6 cases were located on the ventral side of the spinal cord). The maximum diameter ranged from 0.5 to 3.0 cm. The clinical manifestations included neck, shoulder or upper limb pain 43 cases, sensory disturbance (numbness) in 22 cases, and limb weakness in 8 cases. The microchannel keyhole technique was used to expose the tumor, and the tumor was resected microscopically. RESULTS: In this study, 35 patients underwent hemilaminectomy, 12 patients underwent interlaminar fenestration, 2 patients underwent medial 1/4 facetectomy on the basis of hemilaminectomy or interlaminar fenestration. Two tumors were resected through anatomy space (no bone was resected). The degree of tumor resection included total resection in 50 cases and subtotal resection in 1 case. The type of the tumor included 36 schwannomas, 12 meningiomas, 2 enterogenic cysts and 1 dermoid cyst. There was no infection and cerebrospinal fluid leakage postoperatively. Limb numbness occurred in 7 patients. The average follow-up time was 15 months (3 to 36 months). No deformity such as cervical instability or kyphosis was found. The tumor had no recurrence. CONCLUSION: The cervical spinal canal is relatively wide, cervical tumors with no more than three segments can be fully exposed by means of microchannel technology. Besides intramedullary or malignant tumors, they can be microsurgically removed. Preservation of the skeletal muscle structure of cervical spine is beneficial to recover the anatomy and function of cervical spine. The electrophysiological monitoring helps to avoid spinal cord or nerve root injury.

Digital exoscope versus surgical microscope in spinal dural arteriovenous fistula surgery: a comparative series.

OBJECTIVE: Surgical treatment of spinal dural arteriovenous fistulas (DAVFs) has been reported to be superior to endovascular treatment in terms of occlusion of the fistula. Despite the increased availability of digital 3D exoscopes, the potential benefits of using an exoscope in spinal DAVF surgery have not been studied. The purpose of this study was to report and compare the results of exoscope- and microscope-assisted surgery for spinal DAVFs. METHODS: All consecutive adult patients (≥ 18 years of age) treated surgically for spinal DAVFs from January 2016 to January 2023 in a tertiary neurosurgical referral center were included. All patients were operated on by one neurosurgeon. Their pre- and postoperative clinical findings, imaging studies, and intra- and postoperative events were evaluated and surgical videos from the operations were analyzed. RESULTS: Altogether, 14 patients received an operation for spinal DAVF during the study period, 10 (71%) with an exoscope and 4 (29%) with a microscope. The DAVFs were most commonly located in the lower parts of the thoracic spine in both groups. The duration of exoscopic surgeries was shorter (141 vs 151 minutes) and there was less blood loss (60 vs 100 ml) than with microscopic surgeries. No major surgical complications were observed in either group. Of the 14 patients, 10 had gait improvement postoperatively: 7 (78%) patients in the exoscope group and 3 (75%) in the microscope group. None of the patients experienced deterioration following surgery. CONCLUSIONS: Exoscope-assisted surgery for spinal DAVFs is comparable in safety and effectiveness to traditional microscopic surgery. With practice, experienced neurosurgeons can adapt to using the exoscope without major additional risks to the patient.

Perioperative analgesic efficacy of lumbar erector spinae plane block in dogs undergoing hemilaminectomy: a randomized blinded clinical trial.

OBJECTIVE: To evaluate the perioperative analgesic effect of the unilateral lumbar erector spinae plane block (ESPBL) in dogs undergoing hemilaminectomy. STUDY DESIGN: Randomized, blinded clinical study. ANIMALS: A total of 30 client-owned dogs undergoing thoracolumbar or lumbar hemilaminectomy for intervertebral disc extrusion (IVDE). METHODS: Dogs were randomly assigned to receive a unilateral ESPBL, performed either with 0.4 mL kg-1 ropivacaine 0.5% [group ROPI (n = 15)] or with saline solution [CNT group (n = 15)]. Dogs were premedicated intravenously (IV) with acepromazine 5 µg kg-1 and methadone 0.2 mg kg-1, general anaesthesia was induced by administering IV midazolam 0.2 mg kg-1 and propofol to effect and maintained with isoflurane. Fentanyl was administered as rescue analgesia. Bradycardia [heart rate (HR) < 60 beats minute-1] with hypotension was treated with atropine IV. The Short-Form of the Glasgow Composite Pain Scale was used pre- and postoperatively at 1, 2, 4, 8, 12, 16, 20 and 24 hours after extubation, and methadone 0.2 mg kg-1 was administered IV when pain score was ≥ 5/20. HR and end-tidal concentration of isoflurane (Fe'Iso) were compared between groups with anova combined with a Dunnet's post hoc test. Time to the first rescue methadone and total dose of fentanyl (FENtot, µg kg-1 hour-1) and methadone (METtot, mg kg-1) in the first 24 postoperative hours were compared using unpaired Student's t test. Postoperative pain scores were compared with the Mann-Whitney test and atropine administration with a Fisher's exact test; p < 0.05. RESULTS: HR, Fe'Iso, FENtot, METtot and atropine administration were significantly lower in group ROPI compared to CNT. Postoperative analgesic effect was significantly longer, and pain scores were significantly lower in group ROPI for all time points. CONCLUSIONS AND CLINICAL RELEVANCE: Unilateral ESPBL with ropivacaine reduced perioperative opioid consumption and the occurrence of bradycardia in dogs undergoing hemilaminectomy.

Residual volume of extruded disc material and residual spinal cord compression measured on postoperative MRI do not predict neurological outcomes in dogs following decompressive surgery for thoracolumbar intervertebral disc extrusion.

Published studies on the validity of using quantitative MRI measures of pre- and postoperative spinal cord (SC) compression as prognostic indicators for dogs undergoing surgery for intervertebral disc extrusion (IVDE) are currently limited. The aim of this retrospective analytical study was to describe the volume of postoperative residual extradural material (VREM) and the ratio of the cross-sectional area (CSA) of maximum SC compression to the CSA of SC in a compression-free intervertebral space as MRI measures of preoperative and postoperative compression (residual spinal cord compression, RSCC), and to compare these measures between the neurological outcome in a group of dogs. Inclusion criteria were dogs that underwent surgery for thoracolumbar IVDE, were imaged pre- and immediately postoperatively by MRI, and had a neurological follow-up examination 2 to 5 weeks postoperatively. Two blinded observers independently performed measurements in pre- and postoperative MRI studies. Dogs were classified into positive outcome (PO) and negative outcome (NO) groups based on follow-up neurologic examination scores. Seventeen dogs were included (12 PO, 5 NO). Interobserver agreement for MRI measurements was good to excellent (ICCs: 0.76-0.97). The prevalence of residual extradural material in postoperative MRI studies was 100%. No significant differences in mean preoperative SC compression, mean RSCC, mean SC decompression, or VREM were found between outcome groups (P = .25; P = .28; P = .91, P = .98). In conclusion, neither postoperative VREM nor RSCC could predict successful neurological outcomes.

What is the Preferable Method for the C3 and C7 Segments in Unilateral Open-Door Laminoplasty for Patients Diagnosed with Cervical Spondylotic Myelopathy?

BACKGROUND: Traditional C3-C7 unilateral open-door laminoplasty (UOLP) often leads to various postoperative complications as a result of damage of cervical posterior muscles and nuchal ligaments. We aimed to thoroughly evaluate postoperative outcomes after our modified UOLP versus traditional UOLP in treating multilevel cervical spondylotic myelopathy (MCSM). METHODS: Seventy-six patients with MCSM who underwent the modified UOLP with C3 laminectomy and C7 upper hemilaminectomy (40 patients) or traditional C3-C7 UOLP (36 patients) were included. Preoperative and postoperative cervical radiologic parameters, as well as clinical and surgical outcomes, were evaluated. RESULTS: Postoperatively, Japanese Orthopaedic Association scores improved significantly more in the modified UOLP group than in the traditional UOLP group (P = 0.028), whereas visual analog scale scores and Neck Disability Index improved similarly in both groups. Follow-up scores for Japanese Orthopaedic Association, Neck Disability Index, and visual analog scale were not significantly different between the 2 groups. At the final follow-up, the C2-C7 sagittal vertical axis and T1 slope increased in the traditional UOLP group and did not change in the modified UOLP group and were unchanged in the modified UOLP group. The C2-C7 Cobb angle decreased significantly in the traditional UOLP group and did not change in the modified UOLP group. The modified UOLP group lost less cervical posterior muscle area compared with the traditional UOLP group (3.72% ± 3.54% vs. 6.67% ± 2.81%; P < 0.001). The range of motion in the modified UOLP group was significantly greater than in the traditional UOLP group at the final follow-up (P < 0.001). Also, the modified UOLP group experienced a notable reduction in operative time, blood loss volume, and postoperative hospital stay. CONCLUSIONS: We recommend performing our modified UOLP with C3 laminectomy and C7 upper hemilaminectomy instead of traditional C3-C7 UOLP.

Tranexamic Acid in Reducing Intraoperative Bleeding in Dogs Undergoing Thoracolumbar and Lumbar Hemilaminectomy and Intervertebral Disc Fenestration.

Hemilaminectomy associated with intervertebral disc fenestration (HF) is the most used spinal decompression surgical technique for the treatment of intervertebral disc extrusion (IVDE). The surgical procedure can be hampered by excessive bleeding from the venous sinuses; however, tranexamic acid intravenously (IV) is a possible adjunct to hemostasis in these patients. This study aimed to verify the effectiveness of tranexamic acid in reducing intraoperative bleeding in dogs with thoracolumbar and lumbar IVDE submitted to HF. Sixteen dogs with IVDE undergoing HF were included. These were distributed into a TXA group (tranexamic acid 20 mg/kg IV bolus, followed by 2 mg/kg/h IV continuous infusion) (n = 8) and a control group, with saline solution (n = 8). Blood loss was measured using the gravimetric method. The difficulty of operative visualization due to bleeding was classified by the surgeon. Median blood loss (%) in patients in the TXA group was lower than those in the control group (2.75 ± 1.23 and 4.99 ± 4.44, respectively) (P = .028). Intraoperative visualization difficulty due to bleeding occurred in 10 patients in the control group, and in no patients in the TXA group. A severe arterial thromboembolic complication was recorded, potentially due to tranexamic acid. The use of intraoperative tranexamic acid was effective in reducing bleeding and facilitating operative visualization in dogs with IVDE undergoing hemilaminectomy and intervertebral disc fenestration.

Application of microchannel technique in minimally invasive resection of cervical intraspinal tumors / 北京大学学报(医学版)

Objective:To explore the application and key points of microchannel approaches in resec-tion of cervical intraspinal tumors.Methods:A retrospective analysis was performed on 51 cases of cervi-cal spinal canal tumors from February 2017 to March 2020.Among them,5 cases were located epidural space,6 cases were located epidural and subdural space,and 40 cases were located under the subdural extramedullary space(6 cases were located on the ventral side of the spinal cord).The maximum diameter ranged from 0.5 to 3.0 cm.The clinical manifestations included neck,shoulder or upper limb pain 43 cases,sensory disturbance(numbness)in 22 cases,and limb weakness in 8 cases.The micro-channel keyhole technique was used to expose the tumor,and the tumor was resected microscopically.Results:In this study,35 patients underwent hemilaminectomy,12 patients underwent interlaminar fenestration,2 patients underwent medial 1/4 facetectomy on the basis of hemilaminectomy or interlaminar fenestration.Two tumors were resected through anatomy space(no bone was resected).The degree of tumor resection included total resection in 50 cases and subtotal resection in 1 case.The type of the tumor included 36 schwannomas,12 meningiomas,2 enterogenic cysts and 1 dermoid cyst.There was no infec-tion and cerebrospinal fluid leakage postoperatively.Limb numbness occurred in 7 patients.The average follow-up time was 15 months(3 to 36 months).No deformity such as cervical instability or kyphosis was found.The tumor had no recurrence.Conclusion:The cervical spinal canal is relatively wide,cervical tumors with no more than three segments can be fully exposed by means of microchannel technology.Besides intramedullary or malignant tumors,they can be microsurgically removed.Preservation of the skeletal muscle structure of cervical spine is beneficial to recover the anatomy and function of cervical spine.The electrophysiological monitoring helps to avoid spinal cord or nerve root injury.

Management of Super-refractory Postoperative Lumbar Cerebrospinal Fluid Leak: A Case Report and Review of the Literature.

One well-documented risk of spinal surgery is cerebrospinal fluid (CSF) leak in the immediate postoperative period. While the majority of CSF leaks occur due to an obvious intraoperative dural tear, several reports have documented delayed CSF leakage from occult intraoperative dural tears. There is a paucity of published literature regarding the true incidence of dural tears in minimally invasive spinal surgery. Furthermore, the types of dural tears that require closure are poorly understood. According to the limited existing literature available, the recommended treatment of dural tears includes primary repair, subarachnoid drainage catheters, and blood patches. However, there are no distinct treatment guidelines between the different etiologies of CSF leakage. The most important aspect in the management of CSF leakage is prevention, including preoperative risk assessment and meticulous intraoperative manipulation. One emerging treatment strategy is to alter the pressure gradient in a manner that stops CSF leakage. This method is based on one of two mechanisms: direct suture or augmented closure with dural substitute material and either reducing the subarachnoid fluid pressure or increasing the epidural space pressure. Bed rest is a key element in the treatment of persistent CSF leaks, as it can reduce the lumbar CSF pressure, thereby preventing CSF leakage. We describe the challenging case of a persistent CSF leak despite multiple attempts at direct repair, as well as our management strategies. Understanding the proper positioning techniques to reduce leakage is crucial for proper management, and orthopedic surgeons, neurosurgeons, and neurointensivists may consider being more aggressive in treating persistent CSF leaks.

Widespread spontaneous spinal epidural hematoma treated with a combined technique using a flexible neuroendoscope after hemilaminectomy: A case report.

Background: One-third of spinal epidural hematomas occur spontaneously, and these may be associated with the acute onset of severe paralysis. Here, we present a case of T4-L4 symptomatic spontaneous spinal epidural hematoma which was successfully removed using a flexible neuroendoscope after hemilaminectomy. Case Description: Using flexible neuroendoscopy, we successfully treated a T4-L4 spinal epidural hematoma in an 89-year-old Japanese female who spontaneously developed back pain and paraparesis. The hematoma was removed utilizing a hemilaminectomy at three vertebral levels (T11, T12, and L1), while the remaining hematoma debris was completely evacuated with flexible neuroendoscopy. Neurological improvement was observed immediately postsurgery. Conclusion: Flexible neuroendoscopy provided a less extensive surgical method for removing a T4-L4 spontaneous epidural hematoma.

Toxoplasma gondii spinal granuloma in a cat.

Case summary: A 7-year-old female spayed domestic shorthair cat was presented with a history of progressive pelvic limb ataxia. A CT scan of the thoracic spine identified an extradural, left lateralised and compressive soft tissue mass at the level of T9. A decompressive hemilaminectomy at the level of T8-T10 and tissue sampling of the mass were performed. Histopathological examination revealed a parasite granuloma caused by Toxoplasma gondii infection. Postoperatively, the cat improved consistently, but mild left pelvic limb lameness remained. At 5 weeks, a recheck CT scan showed a small, enhancing soft tissue lesion in the left epidural space at T9, causing a mild left lateral compression of the spinal cord. After 9 months, the cat acutely deteriorated neurologically and was euthanased without postmortem examination. Relevance and novel information: To our knowledge, this is the first report of a T gondii spinal granuloma in a cat. Such a granuloma should be considered as a differential in cats with evidence of an extradural soft tissue mass.

Investigation of the Efficacy of Bilateral Osteoligamentous Decompression via Hemilaminectomy in Cervical Spondylotic Myelopathy: A Clinical Study.

OBJECTIVE: Cervical stability may deteriorate and kyphotic spinal deformities may develop in cervical spondylotic myelopathy (CSM) after laminectomy or laminoplasty. This study aimed to investigate the therapeutic efficacy of the "bilateral osteoligamentous decompression via unilateral hemilaminectomy approach (UHBOLD)" technique in CSM patients. METHODS: The study included 34 adult patients who underwent UHBOLD surgery for CSM between 2016 and 2022. A record was made for all patients of age, gender, number of operated levels, preoperative and postoperative long-term follow-up VAS scores, Nurick grade values and mJOA scores, kyphosis angles measured on X-ray, and spinal canal areas measured on T2-weighted MR axial images. RESULTS: Preoperative VAS scores of the patients were 6 (4-9), Nurick grade values were 3 (2-5), mJOA scores were 10.50 ± 3.42, kyphosis angles were -13.34 ± 13.69° and spinal canal areas were 87.11 ± 28.30 mm2. In postoperative long-term follow-up of these patients, VAS scores were 2 (1-5), Nurick grade values were 1 (0-5), mJOA scores were 13.94 ± 3.09, kyphosis angles were -15.07 ± 12.78° and spinal canal areas were 149.65 ± 42.57 mm2. A statistically significant difference was determined between the preoperative and the postoperative long-term follow-up VAS scores, Nurick grade values, mJOA scores, and spinal canal areas (P < 0.001). Kyphosis angles were not different (P = 0.198), and no instability was observed in any patient in long-term follow-up. CONCLUSIONS: The UHBOLD technique performed in multilevel CSM patients did not cause any change in cervical lordosis angle in long-term follow-up, did not cause cervical kyphotic deformity or cervical instability, and significantly improved Nurick grade values, and VAS and mJOA scores.

Thoracolumbar Retrolaminar Block: Anatomical and Radiological Study of Injectate Pattern Distribution in Canine Cadavers.

The retrolaminar block is a regional anaesthetic technique, first developed in humans, in which the local anaesthetic is deposited directly onto the dorsal aspect of the thoracic or lumbar vertebral lamina. This study aims to evaluate the distribution of landmark-guided thoracolumbar retrolaminar injections in greyhound cadavers. Thirteen injections of contrast-dye solution were performed in eight cadavers at the level of the twelfth thoracic vertebra (T12), with either 20 mL (n = 8, high volume, HV) or 10 mL (n = 5, low volume, LV) per site. The spread of the injectate was evaluated through computed tomography and transverse anatomical dissection. The groups were compared using the Mann-Whitney U test. The median (range) of the extent of the spread was 4 (2-5) and 3 (2-4) intervertebral foramina in the LV and HV groups, respectively. The median (range) of the spread along the retrolaminar space was 3 (2-3) retrolaminar segments in the LV and 3 (2-4) in the HV group. Epidural and retroperitoneal spread was identified in seven cadavers. Following landmark-guided retrolaminar injections, the injectate spread both in the retrolaminar and paravertebral spaces, without any obvious association between the volume of injectate and the extent of the spread. Further studies are warranted to determine the clinical efficacy of the technique.