Unilateral Laminectomy Approach for the Removal of Spinal Meningiomas and Schwannomas: Impact on Pain, Spinal Stability, and Neurologic Results

Accepted Manuscript Unilateral Laminectomy Approach for the removal of spinal meningiomas and schwannomas. Impact on Pain, Spinal stability and Neurological Results Alfredo Pompili, MD, Fabrizio Caroli, MD, Francesco Crispo, MD, Maddalena Giovannetti, MD, Laura Raus, MD, Antonello Vidiri, MD, Stefano Telera, MD PII:

S1878-8750(15)01300-5

DOI:

10.1016/j.wneu.2015.09.099

Reference:

WNEU 3288

To appear in:

World Neurosurgery

Received Date: 31 May 2015 Revised Date:

23 September 2015

Accepted Date: 24 September 2015

Please cite this article as: Pompili A, Caroli F, Crispo F, Giovannetti M, Raus L, Vidiri A, Telera S, Unilateral Laminectomy Approach for the removal of spinal meningiomas and schwannomas. Impact on Pain, Spinal stability and Neurological Results, World Neurosurgery (2015), doi: 10.1016/ j.wneu.2015.09.099. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT Unilateral Laminectomy Approach for the removal of spinal meningiomas and schwannomas. Impact on Pain, Spinal stability and Neurological Results.

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Alfredo Pompili MD, Fabrizio Caroli MD, Francesco Crispo MD, Maddalena Giovannetti MD*, Laura Raus MD, Antonello Vidiri MD §, Stefano Telera MD

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Department of Neurosurgery, Services of Anesthesiology* and Department of Radiology and Diagnostic Imaging §, “Regina Elena” National Cancer Institute, Rome, Italy

Corresponding author:

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Alfredo Pompili MD

Department of Neurosurgery “Regina Elena” National Cancer Institute. Via Elio Chianesi 53, 00144 Roma, Italy Phone: +390652662721, +393356606945, Fax: +390652666144

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Email : [email protected], [email protected]

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Key words: spinal surgery, spinal schwannoma, spinal meningioma, pain, hemilaminectomy, minimally invasive neurosurgery

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Abbreviations: KPS: Karnofsky Performance Score, MRI: Magnetic Resonance Imaging, CT: Computerized Tomography, CSF: Cerebrospinal Fluid, QoL: Quality of Life, SRS: Stereotactic Radiosurgery

Introduction Total single and/or multi-level laminectomy/laminotomy has been widely used in neurosurgery for the removal of spinal intradural/extramedullary tumors (4, 9, 11, 16). This approach has been advocated to widely expose cord, roots and tumor, thus minimizing the risk of damage due to improper surgical manipulation (11). However, this approach causes the destruction of the posterior bony structures, the interspinous ligament, and detaches the paraspinal muscles bilaterally (2, 19). This may result in at least a 1

ACCEPTED MANUSCRIPT temporary external bracing, severe and prolonged post-operative pain, risk of late spine instability and/or kyphosis (13, 14, 29, 36), as well as persistent back pain (33). For anteriorly placed tumors the cord must be manipulated or rotated after section of the dentate ligament, with increased risk of neural damage.

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Despite the use of microsurgery (5, 35) and the development of minimally invasive techniques, the unilateral approach does not appear to be very popular and/or the approach of choice. Few papers have been published in literature in recent years (1, 3, 20, 23, 27, 30, 31, 32, 34) and neurosurgical textbooks mention its use only for small, laterally located tumors (7, 10, 16). Only recently it has been suggested as a definite valuable surgical option (17). There are no literature data on the length of hospital stay of these patients. As far as post-operative pain is concerned, Tarantino and coworkers report recently about 59,6% of residual back or wound pain after one year, having used the bilateral approach (33).

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In 2008, one of the largest series of spinal schwannomas was published (26). Conventional laminotomy or hemilaminotomy was employed to remove the majority of the lesions. Pain was recognized as the most common presenting symptom irrespectively from tumor level or locations. Even if the Karnofsky Performance Score (KPS) was reported to be significantly higher at the follow-up than pre-operatively, no details specifically addressing pain management and results were given.

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Materials and Methods

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In 2004, we published our first experience with a small series of 10 patients with thoraco-lumbar schwannomas who were operated upon using the unilateral approach (23). At present, we report the results that we obtained in a larger series of patients with both spinal schwannomas and meningiomas.

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97 patients diagnosed with intradural extramedullary tumor were operated upon at our Institution using the limited hemilaminectomy approach between June 2000 and March 2014: 70 had schwannomas (73 tumors), 27 had meningiomas (29 tumors). Other intradural extramedullary tumors were excluded, as well as 5 more patients with posterior meningiomas and bilateral dural involvement, that were operated upon with a bilateral laminotomy. Four patients had multiple tumors: one had 3, the second 2 distinct lumbar schwannomas (Fig. 4A, B), the third and fourth had 2 distinct dorsal meningiomas (Fig. 2A, B).

Surgical Technique The surgical technique was similar to the one that was pioneered by Yasargil in 1991 we described with less details in previous papers (23, 24).

(35)

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The genupectoral position was used for small lumbar tumors in young patients. For all the others the prone position was used to avoid venous stasis in the lower limbs. For dorsal and cervical tumors, the patient was placed in the prone position with his/her head fixed in the cranial 3-pin 2

ACCEPTED MANUSCRIPT headrest to avoid prolonged neck rotation or facial decubitus. Combined motor and somatosensory evoked potentials were routinely monitored in thoracic and cervical tumors. SSEP and MEP did never significantly change during surgery from the baseline recorded after patient positioning on the operating table. Stimulation was used to identify the unaffected rootlets in lumbar and cervical lesions. This allowed safer dissection of the tumor from the main root.

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After careful radioscopic identification, the skin was incised medially for the required length (5-10 cm). A paramedian incision was used for fascial opening and the paraspinal muscles were detached on that site and retracted. Flavectomy of the nearest interlaminar space to the tumor was performed under microscope. Then, a single-level hemilaminectomy was performed with bone forceps and/or high-speed drill. Lateral extension to the joint is generally unnecessary, but partial facetectomy may be sporadically required in patients with bone hypertrophy. Hemilaminectomy should also be extended to the cranial or caudal interlaminar space, and, if necessary, also to a second lamina (Fig.1). Additional space may be gained by removing the most deep portion of the interspinous ligament for 2-3 mm with Kerrison bone forceps. However, it is worth mentioning that, given the patient’s prone position (contrary to the supine used in MRI diagnosis), the tumor (lumbar but also thoracic schwannomas) may migrate cranially with the extension of the cord, due to the position on the operating table. Thus, if the mass is not identified, it should be sought firstly by extending the opening cranially. Intraoperative echography imaging using dedicated probes is helpful before meningeal opening. The dura was then opened paramedially leaving enough medial flap to permit an easy suture. Cord and/or roots are then visualized through a tangential corridor. Visualization may be enhanced by rotating the operating table, to obtain good exposure of the ventral cord. The tumor may be removed “en bloc” (Fig. 3, 4) or piecemeal (Fig. 5), depending on its consistency and size. The use of an ultrasonic aspirator device is required to reduce tumor volume. We resected rather easily only the involved rootlet sparing the main root in schwannomas. In thoracic meningiomas a root may be sacrificed to gain more working space. Section of the dentate ligament to rotate the cord may be unnecessary with this tangential approach (Fig 2, 5)

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Up until 6 years ago, the dura was closed with 5-0 or 6-0 long-term resorbable sutures. Having had two patients requiring surgical revision because of dural closure failure, we prefer at present unresorbable suturing material (6-0 Prolene). In 8 patients with meningioma, whose dura had been partially resected, a patch with fascia and fat was used for a good closure. In these cases and in others where the suture does not seem acceptable, an application of a sheet of dural sealant was useful. The duration of surgery ranged from 100 to 320 minutes (average 160 min). The cases of doublelevel thoracic meningioma, removed in one stage, and the huge cervical dumbbell schwannoma were the most time-consuming. One patient with 3 schwannomas required a second operation after 6 months, due to a missed third tumor. Post-operative pain was treated routinely for 24 hrs through the application of an elastomeric pump which intravenously infused the following analgesics: Morphine hydrochloride 10 mg and Ketorolac 90 mg. Ranitidine 150 mg and Ondansetron 8 mg were also added to the infusion to prevent gastric complications and vomiting. In patients with post-operative radicular and meningeal pain (10/97, 10%), Methylprednisolone 40 to 80 mg/day was administered for 3 to 5 days to 3

ACCEPTED MANUSCRIPT decrease the inflammation due to CSF blood contamination. This limited number of patients also received a more prolonged analgesic therapy, if requested. At six months, all the patients underwent plain dynamic x-rays and MRI. MRI was then repeated every year for the next three years.

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Pain was evaluated preoperatively, at discharge, and 12 months post-operatively using the Dennis Pain Scale (8) (Table 1). Neurological functions and Quality of Life (QoL) were evaluated at admission, at discharge, and the 12 months follow up, either with a modified McCormick Scale as applied by Klekamp (Table 2) for intramedullary tumors (12), or with a standard Karnofsky Performance Score (KPS). Results were then matched and evaluated with the Wilcoxon signed rank test and paired Student t-test.

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We considered 12 months an adequate temporal limit for an honest clinical evaluation of our surgical results.

Results

Meningioma patients included 25 females and 2 males; their average age was 59.5 yrs (17-85). 36 females and 34 males had schwannomas; their average age was 52.5 yrs (28-77).

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Meningiomas were 5 cervical (all F), 21 thoracic (2 double tumors), (20 F, 1 M), 3 lumbar (2F, 1M).

Symptoms

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Schwannomas were cervical in 6 patients (1M, 5 F), dorsal in 27 (17 F, 10 M) and lumbar in 37 (14 F, 23 M). There were 5 dumbbell tumors: 2 cervical and 3 dorsal. One lady had 3 separate lumbar tumors; another 2 (Fig. 4).

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All the 37 lumbar schwannoma patients presented with back and/or leg pain (Table 5); 7 had neurological impairment (4 severe, 3 moderate). Of the 27 with thoracic location, 19 had pain and 8 no pain; 11 had paraparesis/monoparesis: moderate in 5, severe in 6. For cervical locations, pain was present in all 6, severe to moderate tetraparesis in 3 (Table 3). 24/27 patients with meningioma had pain, 18/27 had moderate to severe neurological impairment (Table 4). Sphincter dysfunction was evident in 10 patients (5 schwannomas and 5 meningiomas).

Size At surgery, the intradural schwannomas’ size ranged from 1 to 3.5 cm. Dumbbell tumors had a large extradural portion in 4 out of 5 cases. Meningiomas’ size ranged from 1.5 to 3 cm. 19 of them 4

ACCEPTED MANUSCRIPT were removed with Simpson grade 2 resection (all anterolateral): the dura was coagulated with laser or bipolar cautery; the other 10 had Simpson grade 1 removal. One patient with cervical anterolateral melanocytic schwannoma had incomplete removal due to pial invasion and adhesion to the anterior spinal artery. Complications and immediate post-operative results (Table 3, 4, 5)

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No deaths and/or major complications due to the technique were recorded in this series.

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Pre-operative pain improved dramatically in all those patients reporting it. All the schwannoma patients with pre-operative neurological deficit, as well as 17/18 of the meningioma patients improved neurologically from the first post-operative day (Table 3, 4). Only one with cervical meningioma had transient upper limb weakness with no immediate improvement. 10 patients, 8 with lumbar schwannoma and 2 with thoracic meningioma had persistent orthostatic headache due to CSF loss. Two of the earliest cases had a pseudomeningocele which required reoperation. Ten had some bilateral leg pain and signs of meningeal inflammation owing to blood contamination, which regressed promptly with corticosteroids. Post-operative dysesthesia or hypoesthesia related to the section of the involved rootlet and/or manipulation of the root was recorded in 50% of the patients with lumbar schwannoma. This improved in a short time and was well tolerated by the patients.

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Uncomplicated patients were mobilized on the third day post-operatively, while patients affected by orthostatic headache or meningeal inflammation were mobilized within five days after surgery.

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Continuous analgesic intravenous infusion via the elastomeric pump was discontinued after 24 hrs in 69 cases and analgesic drugs were given only “on demand”. In 28 patients analgesics were given with a scheduled daily regimen for more days and they were progressively tapered accordingly to the pain reduction observed during follow-up. Our suggested pain medication at discharge when requested, was Paracetamol 2000 - 3000 mg/day.

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The overall average length of hospital stay was 8 days (range 5-19). Mean hospital stay in uncomplicated patients was 6 days (range 5-7) None of them required external bracing. According to the Dennis Pain Scale (8) among the schwannoma patients with preoperative pain, 11 were graded P5 (constant pain), 39 P4 and 12 P3. (Table 5) Meningioma patients were 6 P5, 7 P4, 9 P3, and 2 P2. (Table 5) At discharge the grading improved to P2 in 40 and P3 in 22 schwannoma; and to P2 in 21, and P3 in 3 meningioma patients, respectively. The decrement was calculated with the Wilcoxon signedrank test: admission versus discharge: p<0.0001 (schwannomas), p<0.001 (meningiomas).

Follow-up (Table 3, 4, 5) Follow-up duration ranged from 12 to 156 months (average 72 months). 5

ACCEPTED MANUSCRIPT At six months, none of the patients had any residual tumor/recurrence and/or instability at dynamic X-rays and MRI. MRI was then repeated each year for the following 3 years, 62 patients have at present at least 3 years follow up. The patient with malignant melanocitic schwannomas died at 12 months, one patient with C1-C2 meningioma had a small recurrence at 4 years.

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9 patients died due to unrelated diseases in the following years. 12 patients were lost to late followup (more than 12 months). Pain evaluation at 12 months was graded P1 (no pain) for 22 and P2 for 34, and P3 for 6 of the schwannoma patients, those with meningiomas had respectively P1 14, P2 9, P3 1. Grading at discharge versus follow up was calculated with the Wilcoxon test: p<0.0001 (schwannomas), p<0.001 (meningiomas)

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The overall results on pain were also evaluated: discharge versus admission the decrement of pain was significant p<0.0001, as well as discharge versus follow up: p<0.0001 (Table 5).

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Neurological deficits as evaluated at 12 months had improved in all the 39 patients that had preoperative neurological impairment (Table 3, 4). 19 patients recovered neurologically completely, 17 hade some residual spasticity and clinically irrelevant disesthesia/hypoesthesia, 3 were able to walk autonomously with still moderate spasticity and the need of occasional aid. Sphincter dysfunction was the most difficult to recover completely: 5/10 (1 schwannoma, 4 meningioma).

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Both KPS, and modified McCormick scoring (12) applied to the patients with deficit were evaluated with paired Student t-test, and Wilcoxon test. The overall median KPS improved from 60 at admission to 90 at follow up (p<0.0001). For schwannoma patients it improved from an average of 63 to 90 (p<0.0001), for meningiomas from an average of 55 to 80 (p<0.0002). As for modified McCormick scale the overall preoperative score for schwannomas was 63 and dropped to 31 at follow up ( p<0.0001). Similar results were obtained for meningiomas in which the values were 50 and 24 respectively.

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The overall calculation on 39 cases was 121 pre-op and 55 at follow up (p<0.0001). The patient with melanocytic schwannoma died 12 months post-op due to tumor malignant transformation and CNS dissemination. One patient had a recurrent C1-C2 meningioma four years after surgery and was subsequently treated with Stereotactic Radiosurgery (SRS) To note, none of the patients developed iatrogenic kyphosis or required any delayed fusion/instrumentation due to spine instability at follow-up.

Illustrative case #1 (Fig. 2) 6

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77 year old lady, moderately obese with severe and worsening paraparesis for 1 year. Arterial hypertension, no diabetes. MRI revealed 2 distinct spinal intradural extramedullary lesions, both on the left: T7-T8 and T11-T12. The patient was operated upon in a single session. Two separate approaches were adopted: first the cranial tumor, then the caudal one. Both were meningiomas and were removed completely. Early rehabilitation enabled the patient to promptly recover autonomous ambulation. Spasticity regressed 6 months post-op; lower limb strength improved almost completely. Two major procedures (traditional bilateral approach) in a single session would have been contraindicated in the elderly. In addition, external bracing would have been necessary for stability and pain, and mobilization and rehabilitation would have been delayed. Illustrative case #2 (Fig. 3)

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Male, 42 years. Severe left radicular and back pain for 9 months. MRI had showed a small left L2L3 schwannoma and the corresponding root. Thanks to correct positioning and space identification, this schwannoma was removed “en bloc” with microdiscectomy instrumentation by applying a simple interlaminar approach. Post-operatively: complete and immediate pain remission; discharge on day 5. This case represents a paradigm for correct level identification. Illustrative case #3 (Fig. 4)

Illustrative case #4 (Fig. 5)

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Female 45 years. Severe, incapacitating left leg pain. MRI had showed double (triple ?) L4-L5 left intradural tumor. At operation one separate small tumor was removed at first, then a second matryoshka-shaped, larger mass “en bloc”. Immediate postoperative disappearance of pain.

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Discussion

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Female 66 years. Moderate paraparesis worsening since several weeks, back thoracic pain since 2 years. MRI shows an anterior right paramedian T3-T4 meningioma. The operative view shows how the cord is posteriorly displaced and the removal of the tumor is done with minimal cord manipulation thanks to the tangential corridor and view.

The cardinal principles of intraspinal benign tumor resection are: minimizing the intra-operative risk of cord and/or root damage; removing the tumor completely; and avoid spinal deformity and/or instability(14, 16, 17, 26, 29, 30, 35, 36). As the exposure of the cranial and caudal margins of the tumor is crucial, a transosseous, transligamentous corridor is necessary. The question is: how large should this corridor be to ensure safe and effective tumor removal? The rationale for minimally invasive approaches is to preserve structures that may be important for spinal stability (26, 35) In a large series, Guidetti, in late 70’(9), stressed the high risk of cord injury with limited approaches. His pupils published his late series (but with no technical details) in 1995 (4) . Very recently they published a large series where the surgical technique is more detailed and the majority of the patients were operated upon with a standard complete posterior laminectomy or laminotomy (33). Hentchel wrote in a recent textbook: “ …nothing is to be gained by performing a hemi- rather than a complete laminectomy…” (11). By contrast, Ogden, in 2011, reports that 7

ACCEPTED MANUSCRIPT hemilaminectomy is an option that may reduce pain and preserve spinal stability in schwannomas and that this limited corridor should be used for ventral and lateral meningiomas (17).

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Furthermore laminotomy does not avoid potential post-operative spinal instability (13, 18, 36), since the interspinous ligament is sectioned, muscles are bilaterally stripped, denervated and retracted, and the ligamentum flavum is bilaterally disrupted (18). Laminectomy and laminotomy need an external bracing. Post-operative myelopathy is rare but may occur, preceded by spinal deformity, instability and epidural fibrosis (2, 35). Yasargil (35), with his experience in microneurosurgery, and others (5, 20, 27), suggested and pioneered the unilateral approach to almost any type of intradural extramedullary tumor.

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Experience with microsurgical technique applied to disc surgery has demonstrated that limited hemilaminectomy is effective for both visualization and dural closure. Several papers provide technical details to enhance visualization through a narrow corridor (1, 15, 23, 26, 34, 35). Another advantage of this posterolateral approach is in that the tumor is visualized first, facilitating its dissection from roots and cord. The visualization of anteriorly located tumors is easy without any or minimal cord rotation and/or manipulation (3, 35). As far as the results of our series are concerned, it is remarkable that all the patients presented an improvement of their pre-operative pain and more than two thirds were able to suspend a scheduled administration of analgesic drugs soon after surgery.

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Only one of the most recently published papers calls attention to the problem of post-operative and late “pain” (33). Tarantino reported that pain was independent either from tumor location or histology. These parameters were indeterminate also for late postoperative pain. In his series late pain (1 year post-op) was present in 59,6% of the cases, mainly as back or “wound” pain. By contrast, in our series less than 10% had late back pain.

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Prolonged and severe pain of muscular and/or spinal origin lengthens hospital stay, causes patient discomfort and depression, longer home convalescence, higher social and health costs, and possibly leading to litigation (27, 31, 34). This paper does not provide detailed analysis on chronic pain treatment. However our results on pain as a generic main symptom show that the unilateral approach may be superior to the bilateral one. Our results should stimulate more detailed studies which should include drug schedules, consumption, treatment duration, and also an analysis of the overall costs of the treatment of patients with benign intradural tumors, notably meningiomas and schwannomas. In our series the average length of hospital stay after surgery, was 8 days (those cases with orthostatic headache and the two requiring reoperation modified the curve). Excluding them the mean postoperative hospital stay would have been 6 days. This, together with postoperative pain, is an important parameter that must not be ignored and should further be considered in papers dealing with spinal tumor surgery. Our clinical results are excellent in 87% of the cases, good in 11%, and fair in 2% (“fair” identifying a patient with still autonomous ambulation) (Table 3, 4). Autonomic deficits are the most difficult to recover from (16, 26); 5/10 in our series. It is interesting to note, that only one of the 8

ACCEPTED MANUSCRIPT patients with schwannoma and sphincter dysfunction recovered, by contrary 4/5 meningioma patients had a good result for this function. This was independent from tumor location. We do not have any explanation, nor we found data in the literature. Neurological recovery was independent from tumor location. These data are in agreement with all the published series (6, 21, 26, 28, 29, 30) and independent of the approach used.

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From an oncological view, removal was complete and fairly easy in all but one of the schwannoma patients. 19 of the meningiomas were removed with Simpson grade 2 resection (all anterolateral); the other 10 were removed with Simpson grade 1. Among the 62 patients that had 3 years control MRI, one C1-C2 recurrent meningioma was detected MRI. This patient was seen very recently and referred for radiosurgery (less than one cm recurrent tumor). Hence, the minimal approach does not preclude a good oncological result.

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Melanocytic schwannomas are rare and a possibility of malignant transformation exists (17, 22). Our patient had a minimal residual tumor at her 6-month MRI and had successfully recovered from her tetraparesis. Unfortunately, her disease became disseminated with rapid and uncontrolled leptomeningeal diffusion.

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None of our cases had early or late spinal deformity or instability, or needed external bracing. Our complication rate is low: one case had a transient new neurological deficit due to cervical root manipulation; postural headache and meningeal inflammation were practically negligible. The only serious complication was early pseudomeningocele in two patients, which required reoperation. This was due to improper dural closure probably having used absorbable suture. Since we started using unresorbable suturing material and a dural sealant (last 44 cases), this problem did not arise anymore.

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If the limited unilateral approach is used correctly and after a reasonable learning curve, it provides an effective and “large enough” path to the dural sac. Thus, ensuring safe resection of practically all schwannomas and/or meningiomas that are encountered in “normal daily” neurosurgical practice. This approach is a real technical advancement. It prevents instability (14), permits early mobilization and rehabilitation, gives safe exposure minimizing cord manipulation, reduces blood loss, and postoperative pain either at discharge or follow up, avoids the use of bracings, and provides a high percentage of good/excellent results. In our opinion, it should be included as one of the preferred options in current neurosurgical practice.

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29. Seppälä MT, Haltia MJ, Sankila RJ, Jääskeläinen JE, Heiskanen O: Long-term outcome after

removal of spinal schwannomas: a clinicopathological study of 187 cases. J Neurosurg 83: 621-

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626, 1995

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30. Setzer M, Vatter H, Marquardt G, Seifert V, Vrionis FD: Management of spinal meningiomas:

surgical results and a review of the literature. Neurosurg Focus 23 (4): E14, 2007

31. Sim JE, Noh SJ, Song YJ, Kim HD: Removal of intradural-extramedullary spinal cord tumors

with unilateral limited laminectomy. J Korean Neurosurg Soc 43:232-236, 2008

32. Sridhar K, Ramamurthi R, Vasudevan M.C, Ramamurthi B: Limited unilateral approach for

extramedullary spinal tumours. Br.J. Neurosurg, 12:430-433, 1998

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extramedullary tumors: retrospective analysis of 107 cases. Neurosurgery 75: 509-514, 2014

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34. Tredway TL, Santiago P, Hrubes MR, Song JK, Christie SD, Fessler RG: Minimally Invasive

Resection of intradural- extramedullary spinal neoplasms. Neurosurgery 58 (1 Suppl): ONS 52-

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35. Yasargil MG, Tranmer BI, Adamson TE: Unilateral Partial Hemilaminectomy for the Removal

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of Extra- and Intramedullary Tumours and AVMs, in Symon L. (ed.): Advances and Technical Standards in Neurosurgery, Wien: Springer Verlag, 1991, Vol 18, pp 113-132

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36. Yasuoka S, Peterson HA, Laws ER Jr. MacCarty CS: Pathogenesis and prophylaxis of post-

laminectomy deformity of the spine after multilevel laminectomy: difference between children

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and adults. Neurosurgery 9:145-52, 1981

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Table 1 Dennis Pain Scale

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P1: No pain P2: Occasional minimal pain; no need for medication

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P3: Moderate pain, occasionally medications and no interruption of work or activity of daily living P4: Moderate pain, occasionally absent from work; significant changes in activities of daily living

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P5: Constant, severe pain; chronic pain medications

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Modified McCormick Scale (Klekamp)

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Definition Neurologically intact, minimal dysesthesia Mild motor and/or sensory deficit, independent Moderate deficit, functionally impaired, external aid Severe deficit, limited function, dependent Paraplegia or quadriplegia

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Grade I II III IV V

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Table 2

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Patient Location

F, 66

Deficit

Follow-up at 12 months KPS, McCormick

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(C,D,L )

KPS McCormick Post-Op Results at Discharge

L2-L3 left, Limb: severe 3 tumors

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(sex, age)

Neurological

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Table 3. Clinical details of neurologically impaired schwannoma patients

60, III

Unchanged

80, II

mild spasticity 2nd operation for a 3rd tumor

Limb: moderate

70, II

M, 52

L3, right

Limb: severe

60,III

M, 49

T12, left

monoparesis: severe

70, III

Improved

100, I

Improved

90, II

Improved

90, I

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L3, right

F, 64

T12, right monoparesis: severe

M, 51 F, 54

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F, 59

mild spasticity

70, II

Improved

100, I

T12, left

monoparesis: moderate 80, II

Improved

100, I

T9, right

Paraparesis: moderate 70, III

Improved

90, I

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T6, right

Paraparesis:severe, sphincter dysfunction

50, IV

Unchanged,

70, III moderate spasticity, walks autonomously, occasional aid persistent sphincter dysfunction

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F, 63

C2-C3, left Tetraparesis: moderate 60, III

Subtotal removal, Improved

80, II (some weeks before dissemination and death, 12 months post-op), malignant tumor

M, 32

T2-T3, right

Paraparesis:severe

Improved

80, II

F, 55

T12-L1, left

monoparesis, severe

F, 60 M, 68

50, IV

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F, 57

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mild spasticity 100, I

T12, left monoparesis, moderate 60, III

Improved

100, I

C3-C4, right

Tetraparesis, severe, sphincter dysfunction

40, IV

Improved

70, III

M, 48

L1-L2 right

sphincter dysfunction

80, II

F, 48

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Improved

moderate spasticity, walks autonomously, occasional aid persistent sphincter dysfunction 100, I

C5-C6, left Tetraparesis, moderate 60, IV to severe

Improved

90, I

T11, left

Improved

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Improved

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M, 62

70, II

Paraparesis, moderate, 70, III sphincter dysfunction

mild spasticity 80, II mild spasticity, persistent sphincter dysfunction

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M, 30

T4-T5 left Paraparesis, severe

50, IV

M, 47

T2-T3 left Monoparesis, moderate 80, II

Improved

100, I

Improved

90, I

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mild spasticity L1-L2 right

Foot paresis, moderate 80, II

Improved

100, I

M, 64

L1-L2 right

Limb, severe

Improved

90, I

L1, left

Limb, severe sphincter 60, IV dysfunction

Legend:

Improved

80, II mild spasticity, persistent sphincter dysfunction

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C: cervical, T: Thoracic, L: lumbar

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mild spasticity

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M, 25

70, III

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M, 52

KPS: Karnofsky scoring

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Severe paraparesis: ambulation impossible. Moderate: ambulation only with aid. Mild: spasticity, autonomous ambulation.

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Table 4: Clinical details of neurologically impaired meningioma patients Location Neurological

KPS

Post-Op Results at Discharge

Follow-up at 12 months

(sex, age) (C,D,L,)

Deficit

F, 71

C1-C2, right

Tetraparesis: moderate 60, III

F, 48

C1-C2, right

Tetraparesis: moderate 60, III

Improved

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Patient

F, 49

C3-C4, right

Tetraparesis: moderate 60, III

Improved

90, I

F, 71

C4, right

Paraparesis: severe

50, IV

F, 53

T3-T4, right

Paraparesis; severe

50, IV

F, 67

KPS, McCormick

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Improved

80, II

mild spasticity

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100, I

mild spasticity

T7-T8 and Paraparesis: severe D11-D12, left

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Unchanged, transient 80, II Rt upper limb deficit

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Improved

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F, 77

McCormick

50, IV

T3-T4 left Paraparesis: moderate, 60, III sphincter dysfunction

Improved

90, I moderate spasticity, walks autonomously, occasional aid 90, II mild spasticity

Improved

100, I

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T2-T3 right

50, IV

Improved

90, I

F, 59

T1-T2 left Paraparesis: severe 50, IV sphincter dysfunction

Improved

90, I

F, 66

T5-T6 Left Paraparesis: moderate 60, III

Improved

90, I

F, 79

T4-T5 Left Paraparesis: moderate, 60, III sphincter dysfunction

Improved

80, II

T10-T12, Paraparesis: moderate, 60,III Left sphincter dysfunction

Improved

F, 60

T5-T6, Left

Brown- Sequard Syndrome

60,III

Improved

F, 85

T 10, median

Paraparesis, severe

50, IV

F, 69

T7, Right Paraparesis: moderate 60, III to severe, sphincter dysfunction T4-T5, Median

Paraparesis: moderate 70, III

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mild spasticity

90, I

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mild spasticity

Improved

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F, 64

mild spasticity

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F, 62

Paraparesis: severe

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F, 54

Improved

Improved

90, I

70, III moderate spasticity, walks autonomously, occasional aid 80, II mild spasticity, persistent sphincter dysfunction 90, I mild spasticity

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T3-T4,

Paraparesis: moderate 70, III

Improved

Median F, 50

T1-T2 Left Paraparesis: mild

90, I mild spasticity

80, II

Improved

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Legend:

100, I

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F,66

C: cervical, T: thoracic, L: lumbar

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Severe paraparesis: ambulation impossible. Moderate: ambulation only with aid. Mild: spasticity, autonomous ambulation.

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KPS: Karnofsky scoring

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Table 5: Details of the symptom “pain”

Discharge pain

P5 P4

11 39

None None

P3 P2 P1

12 none none

22 40 none

Follow up pain (12 months) None None

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Dennis Grade Preoperative pain

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Schwannoma Patients # 62

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6 34 22

Meningioma Patients # 24 Preoperative pain

Discharge pain

None

Follow up pain (12 months) None None

P5 P4 P3 P2 P1

6 7 9 2 None

None

3 21 None

1 9 14

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Dennis Grade

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Preoperative pain

Discharge pain

P5 P4 P3 P2

17 46 21 2

None None

P1

None

Follow up pain (12 months) None None

61

7 43

None

36

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25

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Dennis Grade

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Patients # 86

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Figures Fig.1. Postoperative 3D CT scan from a patient with low thoracic right schwannoma. The angle of view and the bony window are evident after this 2 level right laminectomy.

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Fig. 2. In A and B T1 weighted MRI after contrast medium in frontal and lateral views. Both tumors are clearly depicted. C: the cranial tumor is exposed, note the compressed cord, the thoracic root, and the wide angle of vision. D: the cord and the saved root after removal. E: the removal of the caudal meningiomas that is dissected from the cord, also at this level the entry corridor is large enough for safe working F: MRI taken after 6 months in lateral view with a small scar in the upper thoracic cord.

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Fig. 3. In A the lateral view of a T2 weighted MRI nicely shows a small roundish schwannoma with its attached rootlet. B: The tumor has been exposed through an enlarged interlaminar approach with limited cranial and caudal bone removal, using the microdiscectomy retractors. C: the affected rootlet has been identified und cut, and the tumor removed in one piece. Fig. 4. In A and B T1 weighted MRI after contrast medium in frontal and lateral views. There are multiple (3?) adjacent schwannomas (T) that displace posteriorly and laterally the cauda. C: intraoperative view of the easy dissection and removal of the most cranial tumor. D: the caudal tumor is one, shaped as a Russian matryoshka, and is also well dissected and removed. E: the cauda is gently reclined to show the filum terminalis.

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Fig. 5. In A and B T1 weighted MRI after contrast medium in lateral and axial views. This anterior, right paramedian tumor severely compresses the upper thoracic cord. C: the tumor has been exposed with a double space hemilaminectomy. It is easily dissectible from the posteriorly displaced cord. D: the tumor has been partially debulked and mobilized. Note the probe inserted cranio-caudally along the cord for continuous neurophysiologic monitoring. E: intraoperative view after the removal. The controlateral and ventral dura are well seen from this lateral approach.

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Spinal intradural-extramedullary tumors are generally removed with bilateral approach We used an unilateral approach for schwannomas and meningiomas removal Results on pain and spine stability were excellent Oncological and neurological results were similar or even better than those reported The unilateral approach should be the procedure of choice for these tumors

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