Why do thoracic epidurals fail?A literature review on thoracic epidural failure and catheter confirmation

Thoracic epidural anesthesia(TEA)has been the gold standard of perioperative analgesia in various abdominal and thoracic surgeries.However,misplaced or displaced catheters,along with other factors such as technical challenges,equipment failure,and anatomic variation,lead to a high incidence of unsatisfactory analgesia.This article aims to assess the different sources of TEA failure and strategies to validate the location of thoracic epidural catheters.A literature search of PubMed,Medline,Science Direct,and Google Scholar was done.The search results were limited to randomized controlled trials.Literature suggests techniques such as electrophysiological stimulation,epidural waveform monitoring,and x-ray epidurography for identifying thoracic epidural placement,but there is no one particular superior confirmation method;clinicians are advised to select techniques that are practical and suitable for their patients and practice environment to maximize success.

Safety and effectiveness of butorphanol in epidural labor analgesia:A protocol for a systematic review and meta-analysis

BACKGROUND Epidural analgesia is the most effective analgesic method during labor.Butorphanol administered epidurally has been shown to be a successful analgesic method during labor.However,no comprehensive study has examined the safety and efficacy of using butorphanol as an epidural analgesic during labor.AIM To assess butorphanol's safety and efficacy for epidural labor analgesia.METHODS The PubMed,Cochrane Library,EMBASE,Web of Science,China National Knowledge Infrastructure,and Google Scholar databases will be searched from inception.Other types of literature,such as conference abstracts and references to pertinent reviews,will also be reviewed.We will include randomized controlled trials comparing butorphanol with other opioids combined with local anesthetics for epidural analgesia during labor.There will be no language restrictions.The primary outcomes will include the visual analog scale score for the first stage of labor,fetal effects,and Apgar score.Two independent reviewers will evaluate the full texts,extract data,and assess the risk of bias.Publication bias will be evaluated using Egger's or Begg's tests as well as visual analysis of a funnel plot,and heterogeneity will be evaluated using the Cochran Q test,P values,and I2 values.Meta-analysis,subgroup analysis,and sensitivity analysis will be performed using RevMan software version 5.4.This protocol was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)Protocols statement,and the PRISMA statement will be used for the systematic review.RESULTS This study provides reliable information regarding the safety and efficacy of using butorphanol as an epidural analgesic during labor.CONCLUSION To support clinical practice and development,this study provides evidence-based findings regarding the safety and efficacy of using butorphanol as an epidural analgesic during labor.

Rare giant intradural epidural hemolymphangioma:A case report

BACKGROUND Hemolymphangioma is a rare,noninvasive benign tumor that originates from vascular and lymphatic malformations.It is usually congenital and can present with varying symptoms depending on its location and size.There are very few reports of hemolymphangiomas within the spinal canal,and giant lesions are exceptionally rare.CASE SUMMARY In July 2023,a 64-year-old male with a giant intravertebral epidural hemolymphangioma from thoracic 11 to lumbar 2(T11-L2)was admitted to the Department of Spine Surgery at the People's Hospital of Binzhou City,China.The patient experienced progressive lumbar and left lower limb pain,numbness,weakness in both lower limbs,and difficulty with urination and defecation.Imaging studies revealed a large cystic mass in the spinal canal at T11-L2.Surgical decompression was performed,and the pathology confirmed hemolymphangioma.CONCLUSION Complete resection of hemolymphangiomas has the best prognosis,and final diagnosis relies on pathologic diagnosis.In this case,the mass was removed intact with a pedicle nail rod system,leading to adequate spinal decompression and restoration of spinal stability.

Advances in epidural labor analgesia:Effectiveness and treatment strategies of butorphanol

In this editorial,we provide a critical review of the article by Tang et al published in the World J Clin Cases,focusing on the utilization of butorphanol for epidural analgesia during labor.Our discussion encompasses recent research developments in epidural labor analgesia,specifically highlighting the current status of clinical applications of butorphanol and associated treatment approaches.Epidural analgesia is widely acknowledged as the primary method for pain management during labor,offering effective and prolonged pain relief while allowing mothers to remain alert and actively participate in the delivery process.Among the various drugs utilized for epidural labor analgesia,butorphanol has received increasing attention due to its potential efficacy and distinctive pharmacological properties.As a synthetic opioid analgesic,butorphanol exhibits both agonistic and antagonistic activity on opioid receptors,striking a balance between analgesia and minimizing side effects.Nevertheless,the safety and efficacy of butorphanol in epidural labor analgesia remains controversial.While certain studies have reported positive outcomes with butorphanol,including effective pain relief and a reduced incidence of side effects,others have raised concerns about its safety and efficacy compared to traditional opioids or alternative analgesics.In addition,the optimal dosing strategy and regimen of butorphanol as an adjuvant in epidural labor analgesia still need to be verified.Through comprehensive synthesis and analysis of existing literature,we aim to evaluate the current evidence regarding the use of butorphanol for epidural labor analgesia,delineate areas of consensus and controversy,and propose future avenues for research and clinical practice in this domain.

Application of dezocine patient-controlled epidural analgesia in postoperative analgesia in patients with total myomectomy

BACKGROUND Uterine fibroids are common benign gynecological conditions.Patients who experience excessive menstruation,anemia,and pressure symptoms should be administered medication,and severe cases require a total hysterectomy.This procedure is invasive and causes severe postoperative pain,which can affect the patient’s postoperative sleep quality and,thus,the recovery process.AIM To evaluate use of dezocine in patient-controlled epidural analgesia(PCEA)for postoperative pain management in patients undergoing total myomectomy.METHODS We selected 100 patients undergoing total abdominal hysterectomy for uterine fibroids and randomized them into two groups:A control group receiving 0.2%ropivacaine plus 0.06 mg/mL of morphine and an observation group receiving 0.2%ropivacaine plus 0.3 mg/mL of diazoxide in their PCEA.Outcomes assessed included pain levels,sedation,recovery indices,PCEA usage,stress factors,and sleep quality.RESULTS The observation group showed lower visual analog scale scores,shorter postoperative recovery indices,fewer mean PCEA compressions,lower cortisol and blood glucose levels,and better polysomnographic parameters compared to the control group(P<0.05).The cumulative incidence of adverse reactions was lower in the observation group than in the control group(P<0.05).CONCLUSION Dezocine PCEA can effectively control the pain associated with total myomectomy,reduce the negative impact of stress factors,and have less impact on patients’sleep,consequently resulting in fewer adverse effects.

Unique method for removal of knotted lumbar epidural catheter: A case report

BACKGROUND Combined spinal-epidural(CSE)anesthesia is the preferred anesthesia method for cesarean delivery.The use of an epidural catheter is essential for administering additional drugs intraoperatively and managing postoperative pain.However,the insertion of epidural catheters is associated with various complications,such as total spinal anesthesia,symptoms indicative of spinal nerve root irritation,and challenges in epidural catheter removal.CASE SUMMARY We present a case report of a challenging epidural catheter removal due to knotting.The lumbar computed tomography scan results revealed that the catheter formed a tight knot in the epidural space.We used a novel extubation method and successfully removed the catheter.CONCLUSION The operator can use opposite forces to"spiral"apart the spinal joints by positioning the patient's body in a specific position.The findings indicate that,when combined with imaging examination results,this method is effective for the removal of epidural catheters.

Management of a Retained Epidural Catheter in a Pregnant Patient: A Case Report and Review of Literature

Background: Epidural anesthesia is an effective intervention to treat labor pain and provide analgesia for orthopedic procedures. A rare complication of this technique is epidural catheter retention. Case Presentation: In this case report, we present an otherwise healthy 21-year-old G2P0010 woman at 39 weeks and 3 days gestation whose anesthetic management was complicated by a symptomatic retained epidural catheter fragment. Computed tomography (CT) imaging of her spine showed the fractured catheter within her paraspinal muscles and neurosurgery recommended no surgical intervention at that time. The patient reported resolution of back pain while in the postpartum unit which she continues to endorse two weeks after discharge. Conclusion: Retained epidural catheter is a medical emergency that requires immediate imaging and neurological evaluation. While magnetic resonance imaging is typically regarded as the standard imaging modality for this complication, in epidural sets that contain metallic components, we suggest using CT to avoid the risk of thermal nerve damage. In cases where the patient does not report any acute complaints, nonsurgical management may be appropriate but close follow-up is required to monitor for catheter migration.

A Structured Method of Teaching Epidural Block reduces the incidence of accidental dural puncture in inexperienced trainees.

Background: The rate of accidental dural puncture is particularly high during the period of training, especially in novices. The structured epidural teaching model (SETM) includes three standardized video lessons, the construction of a 3D epidural module by trainees and practical training by using an epidural simulator with and without the CompuFlo™ Epidural instrument. In this study we report the retrospective analysis of the accidental dural puncture rate of inexperienced trainees during their 6 months clinical practice rotation in obstetrics before and after the introduction of the SETM in our Institution. Method: We evaluated the incidence of accidental dural puncture before the introduction of the SETM methodology and afterwards by analyzing our departmental database from February 2019 to January 2023. All epidural blocks were executed by trainees who had never previously performed an epidural block and were about to begin their obstetrics rotation. Results: We analyzed 7415 epidurals: 3703 were performed before the introduction of the SETM methodology (control group) and 3712 afterwards (study group). The incidence of accidental dural puncture was 0.37% for the control group and 0.13% for the study group (p<.05). The probability of making an accidental dural puncture was 64% (OR: 0.36) lower for trainees who had the training than for those who did not. Conclusions: After the introduction of the structured teaching method, we observed a significant reduction of accidental dural puncture during the training period. We hope that our observation will encourage a constructive discussion among experts about the need to use standardized and validated tools as a valuable aid in teaching epidural anesthesia.

Analgesic Effect of Combined Spinal-Epidural Anesthesia and its Effect on TNF-α and CRP Levels in Elderly Patients with Hip Fracture During Surgical Treatment

Objective:To observe the analgesic effect of combined spinal and epidural anesthesia on older patients undergoing hip fracture surgery.Method:One hundred and twenty elderly hip fracture surgery patients treated in our hospital from January 2021 to December 2022 were selected and randomly divided into two groups,with 60 cases in the experimental group and 60 in the control group.The experimental group was given combined spinal-epidural anesthesia intervention measures,while the control group was given epidural anesthesia intervention measures.The analgesic effect,tumor necrosis factor-alpha(TNF-α),C-reactive protein(CRP)levels,and other observation indicators were analyzed after anesthesia intervention.Result:After the intervention,the analgesic effect and the evaluation results of the subjects in the experimental group were better than those in the control group(P<0.05);the obtained values of TNF-αand CRP levels in the experimental group were higher than those of the control group(P<0.05).Conclusion:The combined spinal-epidural anesthesia intervention demonstrated positive outcomes.The analgesic effect of patients during surgery and their inflammatory factor levels improved,which makes this intervention worthy of clinical application and promotion.

Catheter-Assisted Interlaminar Approach for Cervical Epidural Steroid Injection in Patient with Cervical Stenosis Caused by Ossification of Posterior Longitudinal Ligament: A Case Report

We present the case of a 64-year-old man with cervical ossification of the posterior longitudinal ligament (OPLL) experiencing chronic neck pain and radiculopathy for 6 months. A catheter-assisted interlaminar Cervical Epidural Steroid Injection (CESI) was performed under fluoroscopic guidance, targeting the affected C2-C6 levels. Significant improvement was observed after this procedure, with decreased pain scores (visual analogue scale (VAS) 8 to 2) and improved mobility. This technique not only enhances the effectiveness of CESI but also reduces the likelihood of complications such as stroke or epidural hematoma and thus provides an alternative treatment option for patients with multiple stenotic levels who are unsuitable for surgery or are unresponsive to conservative therapy such as medication or physical therapy.

Safety and effectiveness of electromyography-induced rehabilitation treatment after epidural electrical stimulation for spinal cord injury:study protocol for a prospective,randomized,controlled trial

Epidural electrical stimulation is a new treatment method for spinal cord injury(SCI).Its efficacy and safety have previously been reported.Rehabilitation treatment after epidural electrical stimulation is important to ensure and improve the postoperative efficacy of epidural electrical stimulation in patients with SCI.Considering that electromyography(EMG)-induced rehabilitation treatment can accurately match the muscle contraction of patients with SCI,we designed a study protocol for a prospective,randomized controlled trial.In this trial,on the premise of adjusting the spinal cord electrical stimulator to obtain the maximum EMG signal of the target muscle,patients with SCI receiving epidural electrical stimulation will undergo EMG-induced rehabilitation treatment.Recovery of muscle strength of key muscles,quality of life,safety and therapeutic effects will be monitored.Twenty patients with SCI who are scheduled to undergo epidural electrical stimulation in Shanghai Ruijin Rehabilitation Hospital will be randomly divided into two groups with 10 patients per group.The control group will receive conventional rehabilitation treatment.The EMG-induced rehabilitation group will receive EMG-induced rehabilitation treatment of the target muscles of the upper and lower limbs based on conventional rehabilitation treatment.After rehabilitation treatment,follow up for all patients will occur at 2 weeks and 1,3 and 6 months.The primary outcome measure of this trial will be evaluation of target muscle recovery using the Manual Muscle Testing grading scale.Secondary outcome measures will include modified Barthel Index scores,integrated EMG values,the visual analogue scale,Spinal Cord Independence Measure scores,and modified Ashworth scale scores.The safety indicator will be the incidence of adverse events.This trial will collect data regarding the therapeutic effects of EMG-induced rehabilitation in patients with SCI receiving epidural electrical stimulation for 6 months after rehabilitation treatment.Findings from this trial will help develop rehabilitation methods in patients with SCI after epidural electrical stimulation.This study protocol was approved by Ethics Committee of Shanghai Ruijin Rehabilitation Hospital(Approval No.RKIRB2022-12)on February 15,2022 and was registered with Chinese Clinical Trial Registry(registration number:ChiCTR2200061674;date:June 30,2022).Study protocol version:1.0.

Successful remimazolam sedation-epidural block in an older patient with severe chronic obstructive pulmonary disease:A case report

BACKGROUND Chronic obstructive pulmonary disease(COPD)is associated with high morbidity and mortality rates worldwide.Older patients have a degenerative cardiopulmonary function,weak compensatory capacity,and poor surgical tolerance.Therefore,the mode of anesthesia must be optimized.Remimazolam is a new ultrashort-acting benzodiazepine with a rapid onset of action,rapid metabolism,and mild effects on pulmonary circulation.Remimazolam sedation combined with an epidural block has not been reported in hypertensive older adults with severe COPD and inguinal mass resection.CASE SUMMARY We report the case of a 73-year-old man with hypertension and severe COPD,who underwent resection of an enlarged inguinal mass that he had noticed more than 7 mo before presentation.The patient presented with a“right inguinal mass”and was recommended to undergo an enlarged inguinal mass resection.Surgery was relatively challenging,due to the large mass(13 cm×8 cm×7 cm),hard texture,and poor mobility.Considering the advanced age of the patient,gradeⅢhypertension,and severe COPD,we administered remimazolam combined with an epidural block for anesthesia to ensure perioperative safety and careful consideration.The anesthetic effect was precise;the procedure was performed smoothly without any complications,and the patient was successfully anesthetized.However,anesthetic management in such cases has not yet been reported by previous studies.CONCLUSION Remimazolam sedation combined with an epidural block is safe and effective in older patients with hypertension and severe COPD.

Substance P promotes epidural fibrosis via induction of type 2 macrophages

In response to spinal surgery,neurons secrete a large amount of substance P into the epidural area.Substance P is involved in macrophage differentiation and fibrotic disease.However,the specific roles and mechanisms of substance P in epidural fibrosis remain unclear.In this study,we established a mouse model of L1–L3 laminectomy and found that dorsal root ganglion neurons and the macrophages infiltrating into the wound area released sphingolipids.In vitro experiments revealed that type 1 macrophages secreted substance P,which promoted differentiation of type 1 macrophages towards a type 2 phenotype.High-throughput mRNA-seq analysis revealed that the sphingolipid metabolic pathway may be involved in the regulation of type 2 macrophages by substance P.Specifically,sphingomyelin synthase 2,a component of the sphingolipid metabolic pathway,promoted M2 differentiation in substance P-treated macrophages,while treating the macrophages with LY93,a sphingomyelin synthase 2 inhibitor,suppressed M2 differentiation.In addition,substance P promoted the formation of neutrophil extracellular traps,which further boosted M2 differentiation.Blocking substance P with the neurokinin receptor 1 inhibitor RP67580 decreased the number of M2 macrophages in the wound area after spinal surgery and alleviated epidural fibrosis,as evidenced by decreased fibronectin,α-smooth muscle actin,and collagen I in the scar tissue.These results demonstrated that substance P promotes M2 macrophage differentiation in epidural fibrosis via sphingomyelin synthase 2 and neutrophil extracellular traps.These findings provide a novel strategy for the treatment of epidural fibrosis.

Is It Safe to Perform an Autologous Epidural Blood Patch on Patients with Underlying Spinal Stenosis or Lumbar Disc Disease? Case Report and Literature Review

The most common spinal pathology seen in the obstetric population is lumbar disc herniation. There is currently no literature documenting the safety of performing an epidural blood patch on obstetric patients with underlying spinal pathology. We present a case of a patient with known severe lumbar spinal stenosis with compressive radiculopathy who received a successful epidural blood patch without worsening her underlying neurologic symptoms. Epidural blood patches can be safely performed in this patient population. However, the anesthesiologist should be aware of the risk of potentially worsening preexisting neurological deficits. Thus, we advise caution prior to placing an epidural blood patch on these patients. The risks and benefits of the procedure should be carefully weighed and considered. It is important to have a thorough discussion with the patient regarding the risks of an epidural blood patch prior to performing the procedure.

Extensive Spinal Epidural Abscess: Cord Compression with Permanent Neurological Defects

Spinal epidural abscesses (SEA) are considerably rare and tend to present over two to five vertebral segments. Occasionally, there will be two or more noncontiguous areas of pyogenic collections [1]. Minimal cases have been reported to span the entire vertebral column;a meta-analysis estimates that 1% of all SEA are holospinal [2]. The triad of presenting symptoms includes fever, back pain (often midline), and neurologic defects [1] [2] [3]. Early detection is identified as a critical aspect of improved outcomes. Cases that do not present in this manner or with other masking symptoms can lead to delayed diagnosis, thus delaying treatment. In the event of cord compression, the occurrence of neurologic defects increases. Time from the onset of clinical manifestations to the operating room is crucial in reversing symptoms [2]. This article seeks to review a case of a 65-year-old male that presented to the emergency department (ED) due to a falling second to weakness and thigh pain. On presentation, he was also noted to have rhabdomyolysis causing acute kidney injury (AKI) with tubular necrosis. The patient was admitted to the hospital with a complex history of progressive leg weakness, pain in the lower back, incontinence, and elevated white blood cell count. Days into the admission, a magnetic resonance imaging (MRI) study was performed, which revealed a continuous posterior SEA from C4 to S2 with anterior mass effect causing spinal cord compression. Emergency neurosurgery was scheduled for laminectomies in the cervical, thoracic and lumbar spine to drain the abscess. Evaluation of this complex medical course, surgical approach to drainage of an incessant spinal column abscess, and sustained neurologic defects will be discussed.

Eye Movement Modeling Examples as a Teaching Tool for Epidural Block

Introduction: Video examples with task demonstrations by experts, with the expert’s eye movements superimposed on the task, are known as “eye movement modeling examples” (EMME). We performed this study to evaluate if there were improvements in the performance of anesthesia novice trainees when executing the epidural technique after an EMME of epidural block procedure. Methods: We developed an eye movement modeling example (EMME) from eye tracking recordings made by experienced anesthesiologists with more than 20 years of experience. Forty-two PGY3 anesthesia trainees who had never previously performed an epidural block were randomized to receive (study group) or not receive (control group) the EMME video before their institutional training. All the trainees were evaluated every 10 epidural blocks until the end of the rotation period, by an independent, blinded observer using the Global Rating Scale for Epidural Anesthesia (GRS). Results: Trainees who received the EMME training exhibited more respect for the patient’s tissues (P Discussion: This is the first study that has used the EMME for a practical, clinical teaching purpose on real patients and that has used it as an aid in teaching epidural anesthesia. We demonstrated that inexperienced trainees who received the EMME training improved their proficiency at epidural blocks as compared to those who had no EMME training beforehand. Given this result, we welcome further studies to investigate the impact and the role of EMME on clinical teaching in the field of anesthesia.

Epidural Blood Patches Performed with Miethke Sensor Reservoir for Continuous Intracranial Pressure Monitoring

An epidural blood patch (EBP) is a procedure performed by injecting autologous blood into a patient’s epidural space, usually at the site of a suspected CSF leak. It is typically performed in patients with characteristic postural headaches due to low intracranial pressure. We report a case of a young female with an implanted Miethke Sensor Reservoir, which was used for continuous intracranial pressure (ICP) monitoring during a two-level epidural blood patch. ICP increased only with thoracic injection, suggesting thoracic EBP may have greater efficacy than lumbar EBP in treating SIH and PDPH when the site of CSF leak is unknown.

Dural puncture epidural technique provides better anesthesia quality in repeat cesarean delivery than epidural technique:Randomized controlled study

BACKGROUND Repeat cesarean deliverys involve a longer surgery and more severe visceral traction than primary cesarean deliverys.The dural puncture epidural(DPE)technique provides faster and more effective analgesia for labor,but there is no sufficient evidence to indicate whether it is suitable for parturients undergoing repeat cesarean delivery.AIM To determine the efficacy and safety of the DPE anesthesia technique in patients undergoing repeat cesarean delivery.METHODS Patients undergoing repeat cesarean delivery were randomly divided into the DPE and epidural anesthesia(EA)groups.A 25-G spinal needle was used for dural puncture via a 19-G epidural needle.The patients in the two groups were injected with 5 mL of 2%lidocaine followed by 15 mL of a mixture of 1%lidocaine+0.5%ropivacaine as the epidural dosage.The primary outcome was the onset time of sensory block to the T6 dermatome level and the sensory and motor block degree.RESULTS A total of 115 women were included(EA:57,DPE:58).The mean time to sensory block to the T6 Level was significantly shorter in the DPE group than in the EA group(14.7 min vs 16.6 min;95%confidence interval,13.9 to 15.4 vs 15.8 to 17.4;P=0.001).The cranial sensory block level was significantly higher at 5,10,and 15 min after the initial dose in the DPE group than in the EA group(P<0.05).The sacral sensory block level was significantly higher and the modified bromage score was significantly lower in the DPE group at each time point(P<0.05).Adverse effects and neonatal outcomes were comparable between the two groups(P>0.05).CONCLUSION The DPE technique provided higher-quality anesthesia than the EA technique,with a rapid onset of surgical anesthesia,better cranial and sacral sensory block spread and a higher motor block degree,without increasing the incidence of maternal or fetal side effects in patients undergoing repeat cesarean delivery.

Preprocedure ultrasound imaging combined with palpation technique in epidural labor analgesia

BACKGROUND For parturients with paroxysmal uterine contraction pain,rapid analgesia is needed.We used preprocedure ultrasound imaging combined with the palpation technique in epidural analgesia for labor,and evaluated the usefulness of this technique in epidural labor analgesia.AIM To evaluate the usefulness of preprocedure ultrasound imaging in epidural analgesia for labor.METHODS In this prospective randomized observational study,72 parturients were assigned to two groups(combined or palpation group).The target interspace of all parturients was first identified by the palpation technique.Then in the combined group,preprocedure ultrasound imaging was used before epidural puncture.In the palpation group,only the traditional anatomical landmarks technique(palpation technique)was performed.The primary outcome was total duration of the epidural procedure(for the ultrasound group,the duration of the preprocedure ultrasound imaging was included).The secondary outcomes were the number of skin punctures,the success rate at first needle pass,the number of needle passes,the depth from the skin to epidural space,and the complications of the procedure.RESULTS Total duration of the epidural procedure was similar between the two groups(406.5±92.15 s in the combined group and 380.03±128.2 s in the palpation group;P=0.318).A significant improvement was demonstrated for epidural puncture and catheterization in the combined group.The number of needle passes was 1.14 in the combined group and 1.72 in the palpation group(P=0.001).The number of skin puncture sites was 1.20 in the combined group and 1.25 in the palpation group(P=0.398).The success rate at first needle pass was 88.89%in the combined group and 66.67%in the palpation group(P=0.045).CONCLUSION This study demonstrated that the total duration of epidural procedures with preprocedure ultrasound imaging combined with the palpation technique was not longer than the traditional anatomical landmarks technique,which were performed by six experienced anesthesiologists in parturients with normal weights undergoing labor analgesia.

Modified surgical method of supra-and infratentorial epidural hematoma and the related anatomical study of the squamous part of the occipital bone

BACKGROUND Supra-and infratentorial acute epidural hematoma(SIEDH)is a common posterior cranial fossa epidural hematoma located at the inner surface of the squamous part of the occipital bone(SOB).Traditionally,surgical treatment of the SIEDH requires a combined supra-infratentorial craniotomy.AIM To analyze the morphological characteristics of the SOB and introduce a single supratentorial craniotomy for SIEDH.METHODS Skull computed tomography(CT)scan data from 32 adult patients were collected from January 1,2019 to January 31,2020.On the median sagittal plane of the CT scan,the angle of the SOB(ASOB)was defined by two lines:Line A was defined from the lambdoid suture(LambS)to the external occipital protuberance(EOP),while line B was defined from the EOP to the posterior edge of the foramen magnum(poFM).The operative angle for the SIEDH(OAS)from the supra-to infratentorial epidural space was determined by two lines:The first line passes from the midpoint between the EOP and the LambS to the poFM,while the second line passes from the EOP to the poFM.The ASOB and OAS were measured and analyzed.RESULTS Based on the anatomical study,a single supratentorial craniotomy was performed in 8 patients with SIEDH.The procedure and the results of the modified surgical method were demonstrated in detail.For males,the ASOB was 118.4±4.7 and the OAS was 15.1±1.8;for females,the ASOB was 130.4±5.1 and the OAS was 12.8±2.0.There were significant differences between males and females both in ASOB and OAS.The smaller the ASOB was,the larger the OAS was.The bone flaps in 8 patients were designed above the transverse sinus intraoperatively,and the SIEDH was completely removed without suboccipital craniotomy.The SOB does not present as a single straight plane but bends at an angle around the EOP and the superior nuchal lines.The OAS was negatively correlated with the ASOB.CONCLUSION The single supratentorial craniotomy for SIEDH is reliable and effective.