Custom-tailored minimally invasive partial C2-corpectomy for ventrally located intramedullary cavernous malformation

The role of intraoperative neurophysiological monitoring in intramedullary spinal cord tumor surgery

Intramedullary tumors are a class of central nervous system tumors with an incidence of 2 to 4%. As they are located very deep and frequently cause postoperative neurological complications, surgical resection is difficult. In recent years, many surgeons have performed electrophysiological monitoring to effectively reduce the occurrence of postoperative neurological complications. Modern electrophysiological monitoring technology has advanced considerably, leading to the development of many monitoring methods, such as SSEPs, MEPs, DCM, and EMG, to monitor intramedullary tumors. However, electrophysiological monitoring in tumor resection is still being studied. In this article, we discussed the different monitoring methods and their role in monitoring intramedullary tumors by reviewing previous studies. Intratumorally tumors need to be monitored for a summary of the condition of the patient. Only by using various monitoring methods flexibly and through clear communication between surgeons and neurophysiological experts can good decisions be made during surgery and positive surgical results be achieved.

Case Report: A Case Series Using Natural Anatomical Gaps-Posterior Cervical Approach to Skull Base and Upper Craniocervical Meningiomas Without Bone Removal

Background: Removal of anteriorly located tumors of the upper cervical spine and craniovertebral junction (CVJ) is a particular surgical challenge. Extensive approaches are associated with pain, restricted mobility of neck and head and, in case of foramen magnum and clivus tumors, with retraction of brainstem and cerebellum.

Methods: Four symptomatic patients underwent resection of anteriorly located upper cervical and lower clivus meningiomas without laminotomy or craniotomy using a minimally invasive posterior approach. Distances of natural gaps between C0/C1, C1/C2, and C2/C3 were measured using preoperative CT scans and intraoperative lateral x-rays.

Results: In all patients, safe and complete resection was conducted by the opening of the dura between C0/C1, C1/C2, and C2/C3, respectively. There were no surgical complications. Local pain was reported as very moderate by all patients and postoperative recovery was extremely fast. All tumors had a rather soft consistency, allowing mass reduction prior to removal of the tumor capsule and were well separable from lower cranial nerves and vascular structures.

Conclusion: If tumor consistency is appropriate for careful mass reduction before removal of the tumor capsule and if tumor margins are not firmly attached to crucial structures, then upper cervical, foramen magnum, and lower clivus meningiomas can be safely and completely removed through natural gaps in the CVJ region. Both prerequisites usually become clear early during surgery. Thus, this tumor entity may be planned using this minimally invasive approach and may be extended if tumor consistency turns out to be less unfavorable for resection or if crucial structures cannot be easily separated from the tumor.

[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.

Transoral Removal of Ventrally Located Meningiomas of the Craniovertebral Junction

BACKGROUND

Surgical treatment of ventral pathologic lesions of the craniovertebral junction and upper cervical spine is extremely difficult due to limited accessibility, as well as the difficulty of performing surgical manipulations in a deep, narrow wound in conditions of restricted surgical freedom and angle of attack.

METHODS

In this article we present 2 clinical cases in which the transoral approach was used to treat ventral meningiomas of the craniovertebral junction. Endoscopic assistance and an original method of anterior atlantooccipital stabilization were used.

RESULTS

Subtotal removal in the first case and complete removal of the tumor in the second case were achieved. In the first case, an unsuccessful attempt of anterior stabilization was made. In the second case, there were no indications for instrumentation (anterior or posterior) as local bone autograft fusion between the condyles and lateral masses of C1 was effectively carried out.

CONCLUSIONS

Previously, the transoral approach garnered interest only from a historical point of view, but with technical progress it has acquired a "second life." Novel surgical techniques allow for a more radical resection of named tumors, as well as lower morbidity and invasiveness of the surgical procedures, which, in the long term, leads to lower complication rates.

Cervical corpectomy for resection of ventral intramedullary capillary hemangioma with circumferential involvement of the anterior spinal artery: case report

There is limited evidence to suggest that anterior approaches for the resection of ventral intramedullary lesions of the cervical spinal cord may result in superior neurological outcomes compared with those following more traditional posterior approaches. To the authors' knowledge, no report of an anterior approach to resect a ventral intramedullary capillary hemangioma exists in the literature. In the following paper, the case of a 75-year-old male who presented with progressive neck and left shoulder pain, weakness of the left hand, myelopathy, and gait imbalance is reported. Postcontrast T1-weighted MRI demonstrated a homogeneously enhancing intramedullary lesion with associated severe impingement of the cervical spinal cord at C-4. Following a C-4 corpectomy, intradural exposure revealed a vascular lesion that circumferentially enveloped the anterior spinal artery. Gross-total resection of the lesion was performed, followed by reconstruction of the corpectomy defect, without neurological deterioration. Pathology was consistent with capillary hemangioma. In this instance, the anterior approach helped to avoid unnecessary neural manipulation and allowed for early identification of normal proximal and distal segments of the anterior spinal artery, which facilitated safe dissection and gross-total removal.

Intramedullary spinal cavernoma: clinical presentation, microsurgical approach, and long-term outcome in a cohort of 48 patients

OBJECT Intramedullary spinal cavernoma (ISC) is a rare entity and accounts for approximately 5%-12% of all spinal vascular pathologies. The purpose of the present study was to examine the influence of clinical presentation, localization, and different surgical approaches on long-term outcome in patients treated for ISC. METHODS The authors performed a retrospective single-center study of 48 cases of ISC treated microsurgically over the past 28 years. Analyzed factors included preoperative clinical history, microsurgical strategies, neurological outcome (American Spinal Injury Association [ASIA] grade, Epstein and Cooper grade), and the occurrence of postoperative spinal ataxia. Univariate analysis was performed to identify factors influencing long-term outcome. RESULTS Preoperatively, 18.8% of all patients experienced a slow, progressive decline in neurological function and 33.3% suffered repetitive episodes of acute neurological deterioration over a time frame of months to years. Moreover, 16.7% noted the sudden onset of a severe neurological deficit, whereas 25% experienced the sudden onset of symptoms with a subsequent gradually progressive decline in neurological function. On long-term follow-up after treatment (mean ± SD, 79.3 ± 35.2 months), 70.8% of patients showed no change in neurological function, 6.3% suffered from a decline, and 22.9% improved neurologically. Thoracolumbar localization (p = 0.043), low preoperative Epstein and Cooper grade for the lower extremities (p < 0.001), and a low preoperative ASIA grade (p < 0.001) were identified as factors associated with an unfavorable outcome (ASIA Grade A-C). The rate of spinal ataxia related to surgical approach was 16.7%. CONCLUSION Postoperative neurological function in ISC patients is determined by the preoperative neurological status. On long-term follow-up after microsurgical treatment, 93.7% of patients presented with a stable or improved condition (ASIA grade); thus, definite microsurgical treatment should be considered as long as patients present with only mild symptoms after the diagnosis of symptomatic ISC.

Minimally invasive approach for small ventrally located intradural lesions of the craniovertebral junction

OBJECT

The surgical management of lesions ventral to the neuraxis at the level of the craniovertebral junction (CVJ) and upper cervical spine is challenging. Here, the authors describe a minimally invasive dorsal approach for small ventrally located intradural lesions at the CVJ as an alternative for the more extensive classic transoral approach or variants of suboccipital approaches.

METHODS

Between 2012 and 2014, 6 symptomatic patients with a small lesion of the ventral aspect at the CVJ level were treated using a minimally invasive dorsal approach at the University Medical Center in Hamburg-Eppendorf, Germany. The anatomical distance between the posterior atlantooccipital membrane and the posterior atlantoaxial ligament, as determined by CT images, was assessed in the treated patients and in 100 untreated persons.

RESULTS

The authors treated 6 patients (mean age 54.7 years) who had a clinical presentation of mild neurological symptoms that disappeared after resection. Minimally invasive surgical dorsal access was achieved by using tubular systems and using the natural space between the occiput (C-0) and C-1, and in 1 case between C-1 and C-2, without having to remove bony structures. The postoperative course in each of the 6 patients was uneventful. The neuropatho-logical findings confirmed a meningotheliomatous meningioma (WHO Grade I) in 5 cases and an extramedullary cavernous hemangioma in 1 case. MRI confirmed complete resection of all the lesions. The atlantooccipital distances ranged from 3 to 17 mm (mean 8.98 mm) in the supine neutral position, and the atlantoaxial distances ranged from 5 to 17 mm (mean 10.56 mm). There were no significant differences between women and men (atlantooccipital p = 0.14; atlantoaxial p = 0.72).

CONCLUSIONS

The results of this study demonstrate that the minimally invasive dorsal approach using the space between C-0 and C-1 or C-1 and C-2 provides direct and sufficient exposure for the safe surgical resection of small ventrally located intradural lesions at the CVJ level while reducing the necessity for musculoskeletal preparation to a minimum.