Anterior to Dorsal Root Entry Zone Myelotomy (ADREZotomy): A New Surgical Approach for the Treatment of Ventrolateral Deep Intramedullary Spinal Cord Cavernous Malformations

A novel lateral myelotomy approach for the treatment of lateral or ventrolateral spinal gliomas

OBJECTIVE

To describe a novel surgical approach in which myelotomy was performed lateral to the dorsal root entry zone (LDREZ), for the treatment of lateral or ventrolateral spinal intramedullary glioma.

METHODS

This study reviewed six patients with lateral or ventrolateral spinal intramedullary glioma who received surgical treatments by using myelotomy technique of LDREZ approach. The patient's clinical characteristics, magnetic resonance imaging (MRI) results, and follow-up outcomes were analyzed. The neurological function of patients before and after operation was assessed based on the Frankel scale system. The anatomical feasibility, surgical techniques, advantages and disadvantages of LDREZ approach were analyzed.

RESULTS

Myelotomy technique of LDREZ approach was employed in all 6 patients. Gross total resections were achieved in 4 patients, and 2 patients with astrocytoma (case 2, 6) underwent partial removal. The perioperative recovery was all smooth and all the patients were discharged on schedule. All the patients who suffered from neuropathic pain were relieved. After surgery, neurological function remained unchanged in 3 patients. 2 patients improved from Frankel grade B to C, and 1 patient deteriorated from Frankel grade D to C immediately after surgery and returned to Frankel grade D at 3 months follow-up. Regarding to the poor prognosis of high-grade glioma, the two cases with WHO IV glioma didn't achieve long survival.

CONCLUSION

LDREZ approach is feasible and safe for the surgical removal of lateral or ventrolateral spinal gliomas. This approach can provide a direct pathway to lateral or ventrolateral spinal gliomas with minimal damage to normal spinal cord.

Surgical timing and long-term outcomes in patients with severe haemorrhagic spinal cord cavernous malformations

BACKGROUND

Surgical resection of the lesions remains the main treatment method for most symptomatic spinal cord cavernous malformations (SCCMs) to eliminate the occupation and associated subsequent lifelong haemorrhagic risk. However, the timing of surgical intervention remains controversial, especially for patients in the acute stage after severe haemorrhage.

METHODS

Patients diagnosed with SCCMs who were surgically treated between January 2002 and December 2021 were selected and retrospectively reviewed. The Modified McCormick Scale (MMS) was used to evaluate neurological and disability status. All medical information was reviewed, and all patients were followed up for at least 6 months.

RESULTS

A total of 279 patients were ultimately included. With regard to long-term outcomes, 110 (39.4%) patients improved, 159 (57.0%) remained unchanged and 10 (3.6%) worsened. For patients with an MMS score of 2-5 on admission, in univariate and multivariate analyses, a ≤6 weeks period between onset and surgery (adjusted OR 3.211, 95% CI 1.504 to 6.856, p=0.003) was a significant predictor of improved MMS. Among 69 patients who first presented with severe haemorrhage, undergoing surgery within 6 weeks of the onset of severe haemorrhage (adjusted OR 4.901, 95% CI 1.126 to 21.325, p=0.034) was significantly associated with improvement of MMS score.

CONCLUSION

Surgical timing can influence the long-term outcome of SCCMs. For patients with symptomatic SCCMs, especially those with severe haemorrhage, early surgical intervention within 6 weeks can provide more benefit.

Intramedullary spinal cavernous malformations with high ossification: a case report and review of the literature

BACKGROUND

Cavernous malformations of the spinal cord are a rare type of vascular malformation, comprising approximately 5 to 16% of all vascular lesions in the spinal cord. Depending on their origin position, these malformations can be distributed in different locations within the spinal canal. Although intramedullary cavernous malformations have been reported in the literature, they are exceedingly rare. Furthermore, highly calcified or ossified intramedullary cavernous spinal malformations are even rarer.

CASE PRESENTATION

Here, we present a case report of a 28-year-old woman diagnosed with a thoracic intramedullary cavernous malformation. The patient had been experiencing progressive numbness in her distal limbs for a period of 2 months. During routine lung computed tomography screening for COVID-19, a hyperdense mass was noted in the patient's spinal canal. Magnetic resonance imaging revealed a mulberry-shaped intramedullary mass at the T1-2 level. The patient underwent surgical treatment, during which the entire lesion was successfully removed, resulting in a gradual improvement of her symptoms. Histological examination confirmed the presence of cavernous malformations with calcification.

CONCLUSIONS

Intramedullary cavernous malformations with calcification are rare and special type that should be treated surgically in the early stage without significant neurological impairment before rebleeding or enlargement of the lesion can occur.

Surgical approaches to intramedullary spinal cord astrocytomas in the age of genomics

Intramedullary astrocytomas represent approximately 30%–40% of all intramedullary tumors and are the most common intramedullary tumor in children. Surgical resection is considered the mainstay of treatment in symptomatic patients with neurological deficits. Gross total resection (GTR) can be difficult to achieve as astrocytomas frequently present as diffuse lesions that infiltrate the cord. Therefore, GTR carries a substantial risk of new post-operative deficits. Consequently, subtotal resection and biopsy are often the only surgical options attempted. A midline or paramedian sulcal myelotomy is frequently used for surgical resection, although a dorsal root entry zone myelotomy can be used for lateral tumors. Intra-operative neuromonitoring using D-wave integrity, somatosensory, and motor evoked potentials is critical to facilitating a safe resection. Adjuvant radiation and chemotherapy, such as temozolomide, are often administered for high-grade recurrent or progressive lesions; however, consensus is lacking on their efficacy. Biopsied tumors can be analyzed for molecular markers that inform clinicians about the tumor’s prognosis and response to conventional as well as targeted therapeutic treatments. Stratification of intramedullary tumors is increasingly based on molecular features and mutational status. The landscape of genetic and epigenetic mutations in intramedullary astrocytomas is not equivalent to their intracranial counterparts, with important difference in frequency and type of mutations. Therefore, dedicated attention is needed to cohorts of patients with intramedullary tumors. Targeted therapeutic agents can be designed and administered to patients based on their mutational status, which may be used in coordination with traditional surgical resection to improve overall survival and functional status.

The Long-Term Outcome in a Cohort of 52 Patients With Symptomatic Intramedullary Spinal Cavernous Hemangioma After Microsurgery and Emergency Rescue Surgery

Background

Surgery is the mainstay treatment for patients with symptomatic intramedullary spinal cavernous hemangioma (ISCH), however the time of surgical intervention remains controversial. In this study, we proposed emergency rescue surgery (ERS) for patients in deteriorative type. The prognostic factors of patients with ISCH after microsurgery and the clinical effect of ERS were analyzed.

Methods

From January 2013 to November 2019, 52 patients with symptomatic ISCH treated by microsurgical treatment were collected, ranging in age from 17 to 66 years old (mean: 45.8 ± 13.5 years). The course of the disease ranged from 2 days to 20 years. Of 52 lesions, 17 lesions were in the cervical segment, 25 in the thoracic segment, and 10 in the lumbosacral segment; while seven cases were at the ventral surface, 25 cases at the dorsal surface, and 20 cases at the central spinal cord. The sagittal diameter ranged from 1 to 58 mm (median: 17.3 mm). The transverse diameter ratio ranged from 20 to 80% (median: 50.7%). Thirty-two patients were diagnosed as deteriorative type and 22 were treated by ERS.

Results

At 12 months after surgery, all patients were followed up, and no residual or recurrence was found in all patients. Twenty-five patients (48.1%) showed spinal cord functional improvement after surgery; 25 (48.1%) had no functional change; 2 (3.8%) got worse. For deteriorative patients, ERS group had a significantly higher improvement rate than the non-ERS group (χ² = 5.393, P = 0.02); For all 52 patients, the factors as a lesion at the ventral surface (Z = 10.453, P = 0.015), or lumbosacral segment (χ² = 9.259, P = 0.010) and longer course of disease (Z = -2.021, P = 0.043) were potential risks in functional recovery in univariate analysis; and in multiple-factor analysis, the lesion at the lumbosacral segment (OR = 4.004, 95% CI: 1.341~11.961, P = 0.013) was the independent risk factors for the functional recovery.

Conclusions

Microsurgical resection is safe and effective for symptomatic ISCH. The ERS is an effective way to improve deteriorative patients' spinal cord function at long-term follow-up. The lesion at the lumbosacral segment is one of the poor prognostic factors.

Resection of Thoracic Intramedullary Breast Metastasis Through the Dorsal Root Entry Zone: 2-Dimensional Operative Video

Intramedullary spinal cord metastases (ISCMs) are rare, representing 8.5% of central nervous system metastases and 5% of intramedullary lesions.¹ With the advent of immunotherapy leading to longer-term survival for cancer patients, intramedullary metastases are on the rise.² A 43-year-old female presented with acute right leg weakness and sensory loss (Video 1). Magnetic resonance imaging revealed an avidly enhancing mass in the spinal cord at T6 with associated edema. Surgical resection was performed for tumor debulking to stabilize and ideally improve neurologic function, as well as for tissue acquisition for molecular profiling and targeted therapy. ISCMs are typically entered via midline myelotomy after a standard posterior exposure.³ However, on dural opening and visualization of the spinal cord, it was apparent that the tumor involved the right T6 nerve root. The decision was then made to enter the lesion via the T6 dorsal root entry zone (DREZ).⁴ Microsurgical resection of the tumor was performed with the aid of ultrasound and D-wave motor monitoring. Postoperative magnetic resonance imaging showed gross total resection and the patient was discharged to acute rehabilitation with increased right leg weakness and stable sensation. We demonstrate that for ISCM involving the exiting nerve root, DREZ myelotomy is a viable alternative to midline myelotomy. We strongly recommend use of D-wave monitoring in such cases as it clearly impacted our ability to maximize the resection. This is the first video where the DREZ approach is emphasized along with utilization of D-wave monitoring. The patient consented to the surgical procedure and the use of intraoperative video for education purposes.

[Surgical treatment of spinal cord cavernous malformations]

Cavernous malformations (CMs) of central nervous system are vascular malformations usually localized in the brain and rarely in the spinal cord. To date, these malformations are well studied. However, some problems of the management of this pathology are still unresolved. This is due to rare localization of intramedullary CMs in the spinal cord and difficult treatment of spinal pathology per se. To date, about 1000 cases of spinal CM are described in the literature. This review is devoted to natural course of disease and postoperative outcomes. These data allow getting a complete picture of modern concepts of the treatment of spinal CMs and formulating the questions requiring further discussion.

The efficacy and deficiency of contemporary treatment for spinal cord arteriovenous shunts

Contemporary treatments for spinal cord arteriovenous shunts are only based on clinicians' treatment experiences and expertise due to its rarity. We reviewed the clinical course of the largest multi-cantered cohort to evaluate the efficacy and deficiency of contemporary interventional treatments for spinal cord arteriovenous shunts. The clinical features, treatment results and clinical outcomes of 463 spinal cord arteriovenous shunts patients were retrospectively assessed. The main outcome was the neurological deterioration that was evaluated based on the modified Aminoff and Logue scale. According to post-treatment DSA, complete obliteration was defined as disappearance of the intradural lesion, whereas partial obliteration was defined as any residual intradural lesion remaining visible and was further categorized as shunt-reduction obliteration (the nidus or shunt points was reduced) or palliative obliteration (only obliterated aneurysms or feeders). Cure rate was 40.6% for whole cohort, 58.5% after microsurgery, and 26.4% after embolization. The curative resection was associated with non-metameric lesions, lesions with a maximum diameter < 3 cm and lesions without anterior sulcal artery supply. The curative embolization was associated with fistula-type lesions, non-metameric lesions, and main drainage diameter < 1.5 mm. Permanent treatment-related neurological deficits rate was 11.2% for the whole cohort, 16.1% after microsurgery, and 5.6% after embolization. The pre-treatment clinical deterioration rate was 32.5%/year, which decreased to 9.3%/year after clinical interventions. After partial treatment, the long-term acute and gradual deterioration rate were 5.3%/year and 3.6%/year, respectively. The acute deteriorations were associated with metameric lesions, craniocervical lesions, lesions with a maximum diameter ≥2 cm and residual aneurysm. Residual aneurysm was the only predictor of acute deterioration for non-metameric spinal cord arteriovenous shunts. The gradual deteriorations were associated with palliative obliteration, absence of pre-treatment acute deterioration and intact main drainage. Although clinical risks of spinal cord arteriovenous shunts were reduced after clinical interventions, contemporary treatments for spinal cord arteriovenous shunt remains associated with considerable risks and incomplete efficacy. Individualized treatment plans should be adopted according to the angioarchitectural features and major clinical risks of specific lesions. There is a higher opportunity for complete obliteration for lesions with simple angioarchitecture. However, regarding most of spinal cord arteriovenous shunts with complex vascular anatomy, partial treatment is the only choice. For these patients, palliative obliteration targeting the aneurysms is recommended for reducing hemorrhagic risk, whereas shunt-reduction obliteration is necessary for non-haemorrhagic myelopathy. Contemporary treatment is ineffective in reducing hemorrhagic risk of incurable metameric spinal cord arteriovenous shunts.

Lateral Myelotomy for Resection of a Ruptured Intramedullary Cervico-Thoracic Cavernous Malformation

BACKGROUND AND IMPORTANCE

Intramedullary spinal cord cavernous malformations represent 5% to 12% of spinal vascular disease. Most patients present with acute or progressive neurological symptoms, including motor weakness or sensory loss. Surgical resection is the only definitive management and is recommended for symptomatic lesions that are surgically accessible.

CLINICAL PRESENTATION

A 35-yr-old woman presented with a sudden onset of pain and temperature sensation loss in the left lower extremity. Magnetic resonance imaging of the spine showed a hemorrhage located ventral and slightly lateral to the right of the midline of the spinal cord from C7 through T3. Ultimately, a right lateral myelotomy between the ventral and dorsal roots was performed, and the cavernous malformation was removed. Postoperative imaging confirmed gross total resection of the cavernous malformation.

CONCLUSION

In this article, we report a highly unusual case of a multisegment, ruptured intramedullary cavernous malformation that was ultimately resected through a lateral myelotomy approach. This case demonstrates that a lateral approach to the spinal cord substance can be utilized for ruptured cavernous malformation, especially if there is hemorrhage at the surface of the spinal cord. This can be used as an entry into the anterolateral compartment of the spinal cord, which would otherwise be regarded as a highly morbid approach due to the sensory deficits induced. We believe this entry point to the spinal cord is feasible in highly select cases such as this.

Anterior Dorsal Root Entry Zone Approach in the Treatment of Spinal Intramedullary Glioma

Surgical removal of lateral or ventrolateral spinal intramedullary gliomas remains a challenge. For lateral or ventrolateral tumors, the dorsal root entry zone (DREZ) myelotomy (equivalent to dorsolateral sulcus approach) and the posterior midline myelotomy would require dissection of the posterolateral tract or posterior column tracts and cause neurologic dysfunction. In Video 1, we introduce a novel approach in which myelotomy was performed anterior to DREZ. The spinal cord was entered between the DREZ and dorsal spinocerebellar tracts, and the surgical path was posterior to the lateral corticospinal tract. Thus no important spinal cord tracts were damaged. The patients with intramedullary glioma depicted in this video had no new neurologic dysfunction postoperatively. This approach has also been reported in treating intramedullary cavernous malformations.¹ Compared with the DREZ approach, myelotomy anterior to the DREZ has 2 advantages. First, the blood vessels anterior to DREZ are always sparser than the posterolateral sulcus. Second, the injury of the somatosensory tract and posterior horn of the spinal cord caused by the dorsolateral sulcus approach can be avoided. Special technique details for this approach are as follows: 1) Myelotomy anterior to DREZ can be optional for selective cases of lateral or ventrolateral intramedullary tumor. 2) It is difficult for cervical intramedullary tumors because the cervical dorsal roots always cover the area of the anterior DREZ. 3) It is useful for a multisegment tumor to cut the dentate ligament. 4) Hemilaminectomy can be used in selective cases for this approach.

Characteristics and Long-Term Outcome of 20 Children With Intramedullary Spinal Cord Cavernous Malformations

BACKGROUND

No prior reports have focused on the natural history and long-term outcomes of intramedullary spinal cord cavernous malformations (ISCCMs) in children.

OBJECTIVE

To investigate the clinical characteristics and long-term outcomes of pediatric ISCCMs and identify the risk of hemorrhage.

METHODS

We retrospectively reviewed a series of 20 pediatric patients (<18 yr old) from a consecutive series of 254 patients with ISCCMs evaluated at a single institution.

RESULTS

Of the 20 pediatric patients, 9 (45.0%) presented with a severe neurological and disability status. The annual hemorrhagic rate in pediatric patients was 8.2%/patient/year. After initial overt hemorrhage events, the annual overt rehemorrhage rate increased to 30.7%/patient/year. In 234 adult patients, the respective rates were 2.8% and 7.4%. Thoracic or lumbar level lesions (P = .002, OR = 3.425, 95% CI = 1.588-7.387) and rehemorrhagic events (P = .005, OR = 3.209, 95% CI = 1.415-7.279) were more likely to follow an aggressive course. There were no significant differences in the sex distribution, location and size of lesions, types of symptoms, likelihood of a severe neurological and disability status, or immediate and long-term postoperative outcomes between pediatric and adult patients with ISCCMs

CONCLUSION

The annual overt hemorrhage rate and rehemorrhage rate of ISCCMs were higher in affected children than in affected adults. Surgical resection of pediatric ISCCMs remains the preferred therapeutic option and provides favorable outcomes.

Coexistence of Intracranial and Spinal Cord Cavernous Malformations Predict Aggressive Clinical Presentation

Background: Patients with spinal cord cavernous malformations (CMs) are at increased risk for multiple neuraxis CMs. Few studies focused on the natural history of patients with coexistence of intracranial and spinal cord CMs.

Methods: Forty patients who underwent both intracranial and spinal MR imaging from a single center were reviewed retrospectively. American Spinal Injury Association (ASIA) impairment scale was used to evaluate neurological and disability status.

Results: The median age of the 40 patients was 40.6 years old (range 9–69), and the male-to-female ratio was 2.1:1. The mean size of the intramedullary lesions was 10.1 ± 5.8 mm (range, 3.0–34.0 mm). Six patients (15%) harbored at least one intracranial lesion. Five of the 6 patients (83.3%) suffered aggressive clinical presentations with severe neurological and disability status; in patients with sporadic spinal CMs, the proportion was 26.5% (9 of 34). Coexistence of intracranial and spinal cord CMs is more likely to follow an aggressive course (P = 0.031, OR = 19.547, 95% CI = 1.322–289.123). In the postoperative long-term follow up, the unfavorable rate of patients with associated intracranial CMs was significantly higher than that of patients with sporadic spinal cord CMs (P = 0.049).

Conclusions: The prevalence of associated intracranial CMs in patients with spinal cord CMs was 15%. Coexistence of intracranial and spinal cord CMs is more likely to follow an aggressive course. This study highlights the necessity of intracranial MR imaging for patients with spinal cord CMs to benefit to the predicting prognosis and selection of treatment strategies.

Surgical approaches and long-term outcomes of intramedullary spinal cord cavernous malformations: a single-center consecutive series of 219 patients

OBJECTIVE

Optimal surgical strategies for intramedullary spinal cord cavernous malformations (ISCCMs) are not optimized and remain problematic. In this study the authors identify rational surgical strategies for ISCCMs and predictors of outcomes after resection.

METHODS

A single-center study was performed with 219 consecutive surgically treated patients who presented from 2002 to 2017 and were analyzed retrospectively. The American Spinal Injury Association (ASIA) Impairment Scale was used to evaluate neurological functions. Patient characteristics, surgical approaches, and immediate and long-term postoperative outcomes were identified.

RESULTS

The average ISCCM size was 10.5 mm. The spinal level affected was cervical in 24.8% of patients, thoracic in 73.4%, and lumbar in 1.8%. The locations of the lesions in the horizontal plane were 30.4% ventral, 41.6% dorsal, and 28.0% central. Of the 214 patients included in the cohort for operative evaluation, 62.6% had superficially located lesions, while 37.4% were embedded. Gross-total resection was achieved in 98.1% of patients. The immediate postoperative neurological condition worsened in 10.3% of the patients. Multivariate logistic regression identified mild preoperative function (p = 0.014, odds ratio [OR] 4.5, 95% confidence interval [CI] 1.4-14.8) and thoracolumbar-level lesions (p = 0.01, OR 15.7, 95% CI 1.9-130.2) as independent predictors of worsening. The mean follow-up duration in 187 patients was 45.9 months. Of these patients, 63.1% were stable, 33.2% improved, and 3.7% worsened. Favorable outcomes were observed in 86.1% of patients during long-term follow-up and were significantly associated with preoperative mild neurological and disability status (p = 0.000) and cervically located lesions (p = 0.009). The depths of the lesions were associated with worse long-term outcomes (p = 0.001), and performing myelotomy directly through a yellowish abnormal surface in moderate-depth lesions was an independent predictor of worsening (p = 0.023, OR 35.3, 95% CI 1.6-756.3).

CONCLUSIONS

Resection performed with an individualized surgical approach remains the primary therapeutic option in ISCCMs. Performing surgery in patients with mild symptoms at the thoracolumbar level and embedded located lesions requires more discretion.