A multilevel posterior tension band-sparing laminectomy for intraspinal lesions: patient series

BACKGROUND

Minimally invasive spine surgery (MISS) represents a major development in spinal tumor surgery. However, considering that many intradural lesions compromise multiple spinal segments, MISS has certain limitations. Thus, some intraspinal lesions still require traditional approaches. Because laminectomy has been shown to predispose patients to kyphosis, laminoplasty and hemilaminectomy are the most widely used approaches to preserve the posterior tension band (PTB). However, these techniques are not devoid of complications. To overcome these issues, the authors modified a previously described technique to preserve the PTB while removing various types of intradural lesions. This procedure was originally designed to treat lumbar stenosis and was modified to avoid muscle ischemia during long procedures.

OBSERVATIONS

Between 2014 and 2021, the authors found 17 cases of spinal lesions with a minimum of 2 years of follow-up after surgical treatment using their approach. No significant postoperative changes in the paraspinal Goutallier grade or spinal angles were observed. The cross-sectional area of the measured paraspinal muscles decreased 6% postoperatively. By performing certain technical modifications in this PTB-sparing (PBS) laminectomy, the authors avoided ipsilateral muscle ischemia.

LESSONS

In this initial series, PBS laminectomy proved to be a safe, versatile, inexpensive, and reliable technique to remove intraspinal lesions.

Awake craniotomy removal of a corticospinal tract developmental venous anomaly hemorrhage: A case report

Developmental venous anomalies (DVAs) are composed of mature venous vessels that lack malformed or neoplastic elements. Although the hemorrhage risk is considered negligible, some patients may have neurological symptoms attributable to acute infarction or intracranial hemorrhage secondary to thrombosis, in the absence of a coexisting cavernous malformation. We report the case of a 42-year-old patient who presented with acute left-hand paresis secondary to a subcortical hemorrhage. This bleeding originated from a DVA in the corticospinal tract area and was surgically drained through an awake craniotomy. To accomplish this, we used a trans-precentral sulcus approach. After the complete removal of the coagulum, small venous channels appeared, which were coagulated. No associated cavernoma was found. Although the main DVA trunk was left patent, no signs of ischemia or venous infarction were observed after coagulating the small venous channels found inside the hematoma cavity. Two weeks after the procedure, the patient's hand function improved, and he was able to resume desktop work. DVA-associated hemorrhage within the cortico-spinal tract could be safely removed with modern awake mapping techniques. This technique allowed the patient to rapidly improve his hand function.

Micromirrors in Neurosurgery: Technical Overview and Benefits Assessment

BACKGROUND

Micromirrors are 45°-angled reflectors able to bring the light beam to regions not accessible to direct vision, thus allowing for inspection of the back of the structure. Introduced in neurosurgery by Prof. Yaşargil in the \'70s, they were progressively abandoned after the advent of the endoscopes despite their cost-effectiveness and easiness to use. In the last few years, the interest for micromirrors awakened because of some theoretical advantages coming from their combination with the microscope. Notwithstanding these premises, still few studies had shed the light on the real advantages of their use in neurosurgery.

OBJECTIVE

To weight the benefits and limitations of intraoperative use of micromirrors in neurosurgery.

METHODS

Surgical cases where micromirrors were employed were retrospectively selected from the surgical database of five different surgeons in different hospitals. Complications directly attributable to the micromirrors were assessed intraoperatively and confirmed with postoperative neuroimaging studies.

RESULTS

Fourteen patients were selected. The site of the lesion was as follows: posterior fossa (43%), frontal lobe (22%), temporal lobe (14%), parietal lobe (7%), insula (7%), and basal ganglia (7%). Five tumors (35%) were gliomas, 3 (21%) epidermoid, and 3 (21 %) supratentorial metastases. Two patients underwent microvascular decompression for neurovascular conflict, and 1 harbored a brain arteriovenous malformation. A gross total resection was achieved in all the tumors and the AVM, while an effective decompression was successfully performed in both patients with conflict. No complications directly attributable to the use of the micromirror occurred. A relatively easy learning curve was noted.

CONCLUSION

Micromirrors proved to be useful in enhancing the visualization of neurovascular structures and pathology residuals within deep-seated surgical fields without the need for fixed brain retraction. Their cost-effectiveness and easy learning curve constitute solid reasons for advocating a revitalization of this "old but gold" tool in neurosurgery.

Use of Saito technique to resect an anterior lumbar spine meningioma: Technical note

Background:

Complete (Simpson Grade I: total removal) resections for anterior spinal meningiomas are especially challenging. This is largely attributed to difficulty obtaining a water-tight dural repair where the tumor has infiltrated the dura requiring duroplasty, thus often resulting in just a Simpson Grade II resection (i.e. coagulation of the dural implantation site). Here, we present a 56-year-old female who underwent resection of a ventral lumbar meningioma utilizing the Saito technique, that effectively separated the dura into two layers, removing just the inner layer but leaving the outer layer intact for direct dural repair.

Methods:

A 56-year-old female underwent a L1–L2 laminectomy. The anterior intradural resection of tumor was achieved with the Saito technique; this required cutting circumferentially around the tumor insertion site, and removing only the inner layer.

Results:

Postoperatively, the patient did well without tumor recurrence over 8 years. The postoperative biopsy confirmed a World Health Organization Grade I meningothelial meningioma.

Conclusion:

Saito’s technique proved to be a safe and effective method for achieving gross total resection of an anterior lumbar meningioma.

An alternative path to atrial lesions through a contralateral interhemispheric transfalcine transcingular infra-precuneus approach: A case report

Background:

The surgical management of lesions located in the trigone of the lateral ventricle remains a neurosurgical challenge. Previously described approaches to the atrium include the transtemporal, parietal transcortical, parietal trans intraparietal sulcus, occipital transcingulate, posterior transcallosal, and transfalcine transprecuneus. However, reaching this area specifically through the cingulate cortex below the subparietal sulcus has not been described thus far.

Case Description:

We present here the removal of a left atrial meningioma through a right parietal “contralateral interhemispheric transfalcine transcingular infra-precuneus” approach and compare it with previously described midline approaches to the atrium. To accomplish this, a right parietal craniotomy was performed. After the left subprecuneus cingulate cortex was exposed through a window in the falx, a limited corticotomy was performed, which allowed the tumor to be reached after deepening the bipolar dissection by 8 mm. Postoperative magnetic resonance imaging showed complete resection of the lesion sparing the corpus callosum, forceps major, and sagittal stratum. Although this approach disrupts the posterior cingulate fasciculus, no deficits have been described so far after unilaterally disrupting the posterior cingulate cortex or the posterior part of the cingulate fasciculus. In fact, a thorough postoperative cognitive examination did not show any deficits.

Conclusion:

The “contralateral interhemispheric transfalcine transcingular infra-precuneus” approach combines the advantages of several previously described approaches. Since it conserves the major white matter tracts that surround the atrium and has a shorter attack angle than the contralateral transfalcine transprecuneus approach, we believe that it could be a potentially new alternative path to reach atrial lesions.

A novel temporary cranial fixation device for awake cranial surgery: Technical report of 14 cases

Background

Awake craniotomy has become the gold standard in various cranial procedures. As part of the awake technique, three-point pin fixation of the patient's head is important. One of the issues we encountered is the problem of matching the scalp infiltration site with the final pin position. To overcome this problem, we developed a flat plunger type fixator that adapts to the Mayfield holder.

Methods

Our fixator has a 2.5 cm metallic shaft that articulates in a ball and socket joint to allow its concave surfaces to adapt to the patient's scalp. After placing the patient in the desired position, the head is fixed with the three plungers, circles are drawn around each plunger, and they are then removed for the circles to be infiltrated with bupivacaine. Standard fixation pins are then placed in the Mayfield holder and aimed at the center of the circles.

Results

So far, we have operated on 14 patients with this technique. No patient experienced pain during temporary fixation, and the drawn circles ensured that there were no mismatches between the local anesthetic and pin locations. The technique was particularly useful on hairy scalps, where infiltration sites were hidden. We also used only 22.5 mg bupivacaine at the pin sites, freeing a dose for the field block around the scalp incision.

Conclusion

The temporary plunger type fixator provided a simple method to economize on local anesthetic use, check the patient's head position before final fixation, and ensure that the Mayfield pins matched with the anesthetized area.

Awake C1-2 laminectomy, instrumentation, and fusion: case report

Surgery of the cervical spine under conscious sedation has been rarely reported in the literature. The main indications are the lack of neurophysiological monitoring and surgery in patients with high cardiovascular risk. To date, no reports of awake C1-2 instrumentation have been published in the English-language literature. The authors present the case of a 76-year-old patient with multiple myeloma and severe cardiomyopathy associated with primary amyloidosis who experienced severe myelopathy from a C2 pseudotumor associated with an odontoid fracture. Due to his high cardiovascular risk, the patient underwent C1 decompression and C1-2 instrumentation and fusion via an awake technique. To accomplish this task, the authors performed multilayered muscular infiltration of local anesthetics and avoided manipulating the C2 root by anchoring C1 with a rod-claw system. The procedure did not last longer than that of general anesthetic approaches, and no complaints were reported by the patient during surgery, which he described as an overall "good experience." The patient was discharged on the 7th postoperative day and resumed his previous work 3 months later. Performing surgery under local anesthesia and conscious sedation reduces the risk of perioperative cardiovascular and respiratory complications in these high-risk patients by avoiding the use of drugs with cardiodepressant effects and endotracheal intubation.

One-stage open reduction of an old cervical subluxation: case report

Study Design Case report. Objective The recommended treatment of cervical subluxation is currently closed or open reduction. These treatments are better accomplished in the acute setting, when muscular and ligamentous laxity allows the required maneuvers to realign the dislocated segments. However, subsets of patients are still being treated subacutely. The majority of the literature addressing subacute subluxations reports treatment through "front and back" approaches, many of them performed in two, three, or even four stages. Other authors recommend days or weeks of traction to reduce the subluxation, followed by anterior or posterior approaches. Herein, we present a one-stage open posterior surgical treatment of a 2-month standing C5-C6 subluxation with "jumped facets," describing a useful technique to reduce these challenging cases without the need of traction or multistage procedures. Methods After opening and exposing the posterior elements, we performed a wide C5-6 bilateral foraminotomy; we then put lateral mass screws and rods from C4 to C6. Resembling the technique used in the reduction of high-grade lumbar spondylolisthesis, we used a rod reducer to bring back the C5 screw head toward the rod, thus realigning the lateral mass screw heads and reducing the subluxation. Results No changes were observed in the motor evoked or somatosensory potentials during this maneuver. Following an uneventful procedure, the patient was transferred to the postanesthetic care unit and discharged 3 days later. Conclusions This open single-stage posterior approach dramatically reduces operating time. This technique could be added into the decision-making armamentarium for cases without disk herniation.

Utility of neurophysiological monitoring using dorsal column mapping in intramedullary spinal cord surgery

OBJECT

Intramedullary spinal cord tumors can displace the surrounding neural tissue, causing enlargement and distortion of the normal cord anatomy. Resection requires a midline myelotomy to avoid injury to the posterior columns. Locating the midline for myelotomy is often difficult because of the distorted anatomy. Standard anatomical landmarks may be misleading in patients with intramedullary spinal cord tumors due to cord rotation, edema, neovascularization, or local scar formation. Misplacement of the myelotomy places the posterior columns at risk of significant postoperative disability. The authors describe a technique for mapping the dorsal column to accurately locate the midline.

METHODS

A group of 10 patients with cervical and thoracic intramedullary spinal cord lesions underwent dorsal column mapping in which a strip electrode was used to define the midline. After the laminectomy and durotomy, a custom-designed multielectrode grid was placed on the exposed dorsal surface of the spinal cord. The electrode is made up of 8 parallel Teflon-coated stainless-steel wires (76-microm diameter, spaced 1 mm apart) embedded in silastic with each of the wires stripped of its insulating coating along a length of 2 mm. This strip electrode maps the amplitude gradient of conducted spinal somatosensory evoked potentials elicited by bilateral tibial nerve stimulation. Using these recordings, the dorsal columns are topographically mapped as lying between two adjacent numbers.

RESULTS

The authors conducted a retrospective analysis of the preoperative, immediate, and short-term postoperative neurological status, focusing especially on posterior column function. There were 8 women and 2 men whose mean age was 52 years. There were 4 ependymomas, 1 subependymoma, 1 gangliocytoma, 1 anaplastic astrocytoma, 1 cavernous malformation, and 2 symptomatic syringes requiring shunting. In all patients the authors attempted to identify the midline by using anatomical landmarks, and then proceeded with dorsal column mapping to identify the midline electrophysiologically. In the 2 patients with syringomyelia and in 5 of the patients with tumors, the authors were unable to identify the midline anatomically with any certainty. In 2 patients with intramedullary tumors, they were able to identify the midline anatomically with certainty. Dorsal column mapping allowed identification of the midline and to confirm the authors' anatomical localization. In 2 patients with intramedullary tumors, posterior column function was preserved only on 1 side. All other patients had intact posterior column function preoperatively.

CONCLUSIONS

Dorsal column mapping is a useful technique for guiding the surgeon in locating the midline for myelotomy in intramedullary spinal cord surgery. In conjunction with somatosensory evoked potential, motor evoked potential, and D-wave recordings, we have been able to reduce the surgical morbidity related to dorsal column dysfunction in this small group of patients.

IMPACT OF COMPENSATORY HYPERHIDROSIS ON PATIENT SATISFACTION AFTER ENDOSCOPIC THORACIC SYMPATHECTOMY

OBJECTIVE

Endoscopic thoracic sympathectomy (ETS) remains the definitive treatment for primary focal hyperhidrosis. Compensatory hyperhidrosis (CH) is a significant drawback of ETS. We sought to identify the predictors for the development of severe CH after ETS, its anatomic locations, and its frequency of occurrence, and we analyzed the impact of CH on patient satisfaction with ETS.

METHODS

Bilateral ETS for primary focal hyperhidrosis was performed in 220 patients, and a retrospective chart review was conducted. Follow-up evaluation was conducted using a telephone questionnaire, and 73% of all patients were contacted. Patients' responses regarding CH and their level of satisfaction after ETS were analyzed. Statistical analysis was performed using SPSS software (Version 14.0; SPSS, Inc., Chicago, IL). A P value of <0.05 was considered statistically significant.

RESULTS

Some degree of CH developed in 94% of patients. The number of levels treated was not related to the occurrence of severe CH. Isolated T3 ganglionectomy led to a significantly lower incidence of severe CH, when compared with all other levels (P < 0.03). Ninety percent of patients were satisfied with the procedure. The development of severe CH, as opposed to mild or moderate CH, significantly correlated with a lower satisfaction rate (P = 0.003).

CONCLUSION

CH is common after ETS procedures, and the occurrence of severe, but not mild or moderate, CH is a major source of dissatisfaction after ETS. The overall occurrence of severe CH is reduced after T3 ganglionectomy as opposed to ganglionectomies performed at all other levels. The level of satisfaction with ETS is high.

Surgical management of chordomas of the cervical spine

OBJECT

Chordomas of the cervical spine are rare tumors. Although en bloc resection has proven to be the ideal procedure in other areas, there is controversy regarding this approach in the cervical spine. The goal in this study was to determine whether piecemeal tumor resection was efficient in the management of chordomas that arise in this location.

METHODS

The authors retrospectively reviewed all 74 cases of chordoma treated by their group. Seven patients with isolated cervical chordomas who were treated between October 1992 and January 2006 were identified. There were four male and three female patients, whose ages ranged from 6 to 61 years (mean 34.4 years). Follow-up duration ranged from 7 to 169 months (median 23 months). All cases were managed using a retrocarotid approach with mobilization of the vertebral artery. When the tumor could not be completely resected via the initial anterior approach, a subsequent posterior resection was performed. Tumor resection was intralesional in all cases, and gross-total tumor resection was achieved in six cases. One patient required a second resection 4 months later. In all cases, a posterior stabilization procedure was performed. Five patients underwent anterior fusion (three with fibular allograft and two with iliac crest), whereas two underwent occipitocervical fusion. In two patients with dedifferentiated chordoma metastasis developed, and one of them died 7 months later. The other patient with metastasis died suddenly at home 26 months postsurgery, presumably from aspiration. At the time of this submission, there were no signs of recurrence in five patients.

CONCLUSIONS

The authors believe that, in most cases, en bloc resection of cervical chordoma is not feasible. This is due to the tendency of chordomas to involve multiple compartments at the time of diagnosis. In the authors' experience, intralesional radical resection remains an effective surgical approach to this disease entity.

Endoscopic resection of thoracic paravertebral and dumbbell tumors

OBJECTIVE

Neurogenic paravertebral tumors are uncommon neoplasms arising from neurogenic elements within the thorax. These tumors may be dumbbell shaped, extending into the spinal canal or exclusively paraspinal. Generally encapsulated, they are located in the posterior mediastinum. In this report, we present our experience in the thoracoscopic resection of these tumors, including surgical technique and potential pitfalls.

METHODS

A retrospective review of patients undergoing endoscopic surgery for paravertebral tumors was undertaken. Patient demographics, charts, operative reports, and pre- and postoperative images were reviewed.

RESULTS

Between 1997 and 2004, 13 patients were treated thoracoscopically for paravertebral tumors in our departments. Our population consisted of four men and nine women. The median age was 44.9 years (range, 29-66 yr). Eight patients presented with pain, dyspnea, cough, and weakness. Five patients had tumors found incidentally. Sizes of the tumors varied from 3 to 9 cm. Final pathology included four neurofibromas, eight schwannomas, and one unclassified granular cell tumor. Gross total resection was achieved endoscopically in all cases. Three patients required a hemilaminectomy for resection of the intraspinal dumbbell component of the tumor during the same operation. The mean operative time was 229.5 minutes. The mean estimated blood loss was 371.1 ml. Postoperative morbidities included one each of tongue swelling, ulnar neuropathy, and intercostal hyperesthesia. The mean hospital stay was 2.8 days.

CONCLUSION

Paravertebral tumors in the posterior mediastinum are amenable to endoscopic removal, even in hard to reach locations. Tumors with intraspinal extension can be removed concurrently by performing a hemilaminectomy, followed by thoracoscopy, without the need for a thoracotomy.

Diagnosis and treatment of spinal cord herniation: a combined experience

OBJECT

Idiopathic spinal cord herniation (ISCH) is an uncommon clinical entity typically presenting with lower-extremity myelopathy. Despite the existence of 85 ISCH cases in the literature, misdiagnosis and delayed diagnosis remain a major concern.

METHODS

The authors conducted a retrospective review of patients who underwent surgery for ISCH at their institutions between 1993 and 2004. Seven patients were treated for ISCH, five in New York and two in Buenos Aires. The patients' ages ranged from 32 to 72 years. There were three men and four women. The interval between the onset of symptoms and surgery ranged from 12 to 84 months (mean 42.1 months). Preoperatively, spinal cord function in four patients was categorized as American Spinal Injury Association (ASIA) Grade D, and that in the other three patients was ASIA Grade C. In all patients a diagnosis of posterior intradural arachnoid cyst had been rendered at other institutions, and three had undergone surgery for the treatment of this entity. In all cases, the herniation was reduced and the defect repaired with a dural patch. The follow-up period ranged from 10 to 147 months (mean 49.2 months). Clinical recovery following surgery varied; however, there was no functional deterioration compared with baseline status. Syringomyelia, accompanied by neurological deterioration, developed post-operatively in two patients at 2 and 10 years, respectively.

CONCLUSIONS

Patients presenting with a diagnosis of posterior intradural arachnoid cyst should be evaluated carefully for the presence of an anterior spinal cord herniation. Based on the authors' literature review and their own experience, they recommend offering surgery to patients even when neurological compromise is advanced.

Occipitocervical fusion after resection of craniovertebral junction tumors

Object

Surgical access to tumors at the craniovertebral junction (CVJ) requires extensive bone removal. Guidelines for the use of occipitocervical fusion (OCF) after resection of CVJ tumors have been based on anecdotal evidence. The authors performed a retrospective study of factors associated with the use of OCF in 46 patients with CVJ tumors. The findings were used to develop recommendations for use of OCF in such patients.

Methods

The authors retrospectively reviewed the cases of 51 patients with CVJ tumors treated by their group between March 1991 and February 2004. Forty-six patients were available for follow up. Charts were reviewed to obtain data on demographic characteristics, presenting symptoms, and perioperative complications. Preoperative computerized tomography scans and magnetic resonance imaging studies were obtained in all patients. Occipitocervical fusion was performed in patients who had undergone a unilateral condyle resection in which 70% or more of the condyle was removed, a bilateral condyle resection with 50% removal, or C1–2 vertebral body destruction. Of the 46 patients, 16 had foramen magnum meningiomas, 17 had chordomas, one had a chondrosarcoma, two had Schwann cell tumors, two had glomus tumors, and eight had other types of tumors. Twenty-three (50%) of the 46 patients underwent OCF, including 15 of the 17 patients with chordomas (88%). None of the patients with meningiomas required fusion. Seventeen (71%) of the 24 patients presenting with neck pain preoperatively underwent OCF.

Conclusions

Patients presenting with neck pain had a 71% chance of undergoing OCF. Patients with chordomas and metastatic tumors were most likely to require OCF. One patient with a 50% unilateral condylar resection returned with OC instability for which OCF was required. Based on their clinical experience and published biomechanical studies, the authors recommend that OCF be performed when 50% or more of one condyle is resected.