Archivos de la categoría Articulos

New proposed classification for lumbar and thoracolumbar deformity

Lumbar and thoracolumbar deformity in the adult is a condition with impairment of health status that can need surgical treatment.

Classification

In contrast with adolescent spinal deformity, where magnitude of the spinal curvature plays a significant role in surgical indication, the aspects relevant in adult spinal deformity are pain and dysfunction that correlate with segment degeneration and imbalance. Previous classifications of adult deformity have been of little use for surgical planning.

Berjano and Lamartina from the IVth Spine Surgery Division, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy, presented a chart review and classification of radiographic and clinical findings.

A classification of degenerative disc disease based on distribution of diseased segments and balance status of the spine is presented.

Four main categories are presented:

Type I (limited nonapical segment disease)

Type II (limited apical segment disease)

Type III (extended segment disease-apical and non apical)

Type IV (imbalanced spine: IVa, sagittally imbalanced; IVb, sagittally and coronally imbalanced).

Types I and II can be treated by fusion of a selective area of the curve.

Type III needs fusion of all the extension of the coronal curve.

Type IV usually needs aggressive corrective procedures, frequently including posterior tricolumnar spine osteotomy. This classification permits interpreting the extension, magnitude and can help establish a surgical plan regarding selective fusion and methods of sagittal correction. Future research is needed to validate the classification 1).

1) Berjano P, Lamartina C. Classification of degenerative segment disease in adults with deformity of the lumbar or thoracolumbar spine. Eur Spine J. 2014 Sep;23(9):1815-24. doi: 10.1007/s00586-014-3219-9. Epub 2014 Feb 23. PubMed PMID: 24563272.

Microsurgery for cerebral arteriovenous malformations: postoperative outcomes and predictors of complications in 264 cases

A total of 264 patients with cerebral arteriovenous malformation were treated with microsurgical resection between 1994 and 2010 at the Jefferson Hospital for Neuroscience. Initial hemorrhage, clinical presentation, Spetzler-Martin AVM grading system (SM), treatment modalities, clinical outcomes, and obliteration rates were reviewed.

Univariate analysis and multivariate analysis were used to determine predictors of operative complications.

Of the 264 patients treated with microsurgery, 120 (45%) patients initially presented with hemorrhage. There were 27 SM Grade I lesions (10.2%), 101 Grade II lesions (38.3%), 96 Grade III lesions (36.4%), 31 Grade IV lesions (11.7%), and 9 Grade V lesions (3.4%). Among these patients, 102 (38.6%) had undergone prior endovascular embolization. In all patients, resection resulted in complete obliteration of the AVM. Complications occurred in 19 (7.2%) patients and resulted in permanent neurological deficits in 5 (1.9%). In multivariate analysis, predictors of complications were increasing AVM size (OR 3.2, 95% CI 1.5-6.6; p = 0.001), increasing number of embolizations (OR 1.6, 95% CI 1.1-2.2; p = 0.01), and unruptured cerebral arteriovenous malformation (OR 2.7, 95% CI 1-7.2; p = 0.05).

Microsurgical resection of AVMs is highly efficient and can be undertaken with low rates of morbidity at high-volume neurovascular centers. Unruptured and larger AVMs were associated with higher complication rates 1).

1) Theofanis T, Chalouhi N, Dalyai R, Starke RM, Jabbour P, Rosenwasser RH, Tjoumakaris S. Microsurgery for cerebral arteriovenous malformations: postoperative outcomes and predictors of complications in 264 cases. Neurosurg Focus. 2014 Sep;37(3):E10. doi: 10.3171/2014.7.FOCUS14160. PubMed PMID: 25175429.

Spinal myxopapillary ependymoma and the role of Radiotherapy

Treatment for spinal myxopapillary ependymoma mainly involves surgical excision of the tumour.

Radiotherapy

If the capsule ruptures or the tumour is not confined to the filum terminale, the mass could infiltrate and adhere to the cauda equina and/or conus medullaris or disseminate via the cerebral spinal fluid 1) 2).

Therefore, adjuvant radiotherapy is recommended when en bloc excision (removal of the entire tumour as one piece) cannot be accomplished 3) 4).

However, the efficacy of radiation therapy has not been established and can result in adverse effects such as radiation myelopathy 5) 6) and residual dysuria 7).

In the series of Tsai et al., the median age at diagnosis was 35 years (range, 8-63 years). Twenty patients (39%) had surgery alone, 30 (59%) had surgery plus radiotherapy (RT), and 1 (2%) had RT only. At a median follow-up of 11 years (range, 0.2-37 years), 10-year overall survival (OS), progression free survival (PFS), and local control (LC) for the entire group were 93%, 63%, and 67%, respectively. Nineteen patients (37%) had disease recurrence, and the recurrence was mostly local (79%). Twenty-eight of 50 patients who had surgery (56%) had gross total resection; 10-year LC was 56% after surgery vs 92% after surgery and RT (log-rank P = .14); the median time of LC was 10.5 years for patients receiving gross total resection plus RT, and 4.75 years for gross total resection only (P = .03). Among 16 patients with subtotal resection and follow-up data, 10-year LC was 0% after surgery vs 65% for surgery plus RT (log-rank P = .008). On multivariate analyses adjusting for resection type, age older that 35 years at diagnosis and receipt of adjuvant radiation were associated with improved PFS (hazard ratio [HR]: 0.14, P = .003 and HR: 0.45, P = .009) and LC (HR: 0.22, P = .02 and HR: 0.45, P = .009).

Postoperative radiotherapy after resection of MPE was associated with improved PFS and LC 8).

1) , 5) Sakai Y, Matsuyama Y, Katayama Y, et al. Spinal myxopapillary ependymoma: Neurological deterioration in patients treated with surgery. Spine. 2009;34:1619–1624.
2) , 3) , 7) Nakamura M, Ishii K, Watanabe K, et al. Long-term surgical outcomes for myxopapillary ependymomas of the cauda equine. Spine. 2009;34:E756–760.
4) , 6) Volpp PB, Han K, Kagan AR, Tome M. Outcomes in treatment for intradural spinal cord ependymomas. Int J Radiation Oncology Biol Phys. 2007;69:1199–1204.
8) Tsai CJ, Wang Y, Allen PK, Mahajan A, McCutcheon IE, Rao G, Rhines LD, Tatsui CE, Armstrong TS, Maor MH, Chang EL, Brown PD, Li J. Outcomes after surgery and radiotherapy for spinal myxopapillary ependymoma: update of the MD anderson cancer center experience. Neurosurgery. 2014 Sep;75(3):205-14. doi: 10.1227/NEU.0000000000000408. PubMed PMID: 24818785.

Management of small vestibular schwannoma: UptoDate

Management of small  vestibular schwannoma consists of 3 options:

Observation with imaging follow-up

Radiosurgery

And/or tumor removal.

Iwao Yamakami et al., report the long-term outcomes and preservation of function after retrosigmoid approach removal and clarify the management paradigm for small tumors.

A total of 44 consecutively enrolled patients with small tumor and preserved hearing underwent retrosigmoid tumor removal in an attempt to preserve hearing and facial function by use of intraoperative auditory monitoring of auditory brainstem responses (ABRs) and cochlear nerve compound action potentials (CNAPs). All patients were younger than 70 years of age, had a small AN (purely intracanalicular/cerebellopontine angle tumor ≤ 15 mm), and had serviceable hearing preoperatively.

According to the American Academy of Otolaryngology Head and Neck Surgery hearing preservation reporting guidelines of the 44 patients were as follows: Class A, 19 patients; Class B, 17; and Class C, 8. The surgical technique for curative tumor removal with preservation of hearing and facial function included sharp dissection and debulking of the tumor, reconstruction of the internal auditory canal, and wide removal of internal auditory canal dura.

For all patients, tumors were totally removed without incidence of facial palsy, death, or other complications. Total tumor removal was confirmed by the first postoperative Gadolinium enhanced MRI performed 12 months after surgery. Postoperative hearing levels were Class A, 5 patients; Class B, 21; Class C, 11; and Class D, 7. Postoperatively, serviceable (Class A, B, or C) and useful (Class A or B) levels of hearing were preserved for 84% and 72% of patients, respectively. Better preoperative hearing resulted in higher rates of postoperative hearing preservation (p = 0.01); preservation rates were 95% among patients with preoperative Class A hearing, 88% among Class B, and 50% among Class C. Reliable monitoring was more frequently provided by CNAPs than by ABRs (66% vs 32%, p < 0.01), and consistently reliable auditory monitoring was significantly associated with better rates of preservation of useful hearing. Long-term follow-up by MRI with Gd administration (81 ± 43 months [range 5-181 months]; median 7 years) showed no tumor recurrence, and although the preserved hearing declined minimally over the long-term postoperative follow-up period (from 39 ± 15 dB to 45 ± 11 dB in 5.1 ± 3.1 years), 80% of useful hearing and 100% of serviceable hearing remained at the same level.

As a result of a surgical technique that involved sharp dissection and internal auditory canal reconstruction with intraoperative auditory monitoring, retrosigmoid removal of small ANs can lead to successful curative tumor removal without long-term recurrence and with excellent functional outcome. Thus, Yamakami et al., suggest that tumor removal should be the first-line management strategy for younger patients with small tumor and preserved hearing 1).

1) Yamakami I, Ito S, Higuchi Y. Retrosigmoid removal of small acoustic neuroma: curative tumor removal with preservation of function. J Neurosurg. 2014 Sep;121(3):554-63. doi: 10.3171/2014.6.JNS132471. Epub 2014 Jul 4. PubMed PMID: 24995779.

Lateral inferior cerebellar peduncle approach

4 patients (3 woman and 1 man) who had a symptomatic dorsolateral brainstem cavernous malformation with radiographic and clinical evidence of hemorrhage, underwent excision via a far lateral suboccipital craniotomy through the foramen of Luschka and with an incision in the cerebellar peduncle.

On intraoperative examination, 2 of the 4 patients had hemosiderin staining on the surface of the peduncle. All lesions were completely excised and all patients had a good or excellent outcome (modified Rankin Scale scores of 0 or 1).

Case series of Deshmuk et al., illustrates that intrinsic lesions of the dorsolateral medulla can be safely removed laterally through the foramen of Luschka and the inferior cerebellar peduncle 1).

1) Deshmukh VR, Rangel-Castilla L, Spetzler RF. Lateral inferior cerebellar peduncle approach to dorsolateral medullary cavernous malformation. J Neurosurg. 2014 Sep;121(3):723-9. doi: 10.3171/2014.5.JNS132276. Epub 2014 Jun 27. PubMed PMID: 24972129.