MR imaging of thoracic disk herniations

Prevalence and Distribution of Incidental Thoracic Disc Herniation, and Thoracic Hypertrophied Ligamentum Flavum in Patients with Back or Leg Pain: A Magnetic Resonance Imaging-Based Cross-Sectional Study

OBJECTIVE

This study is aimed to comprehensively assess the prevalence and distribution of thoracic disc herniation (TDH) or thoracic hypertrophied ligamentum flavum causing stenosis (HLFS) by magnetic resonance image (MRI) in patients with back or leg pain.

METHODS

The study participants included 2212 patients who underwent MRI evaluation for back or leg pain. The prevalence and distribution of TDH or thoracic HLFS were assessed using lumbar MRI with cervicothoracic sagittal images. The presence of TDH or HLFS and the clinical parameters such as age, sex, lumbar surgical need, and thoracic operation were retrospectively reviewed. Logistic regression analysis of the data was followed.

RESULTS

The prevalence rates of TDH and thoracic HLFS in all patients were 6.5% (145/2212) and 19.0% (421/2212), respectively. The prevalence of TDH was demonstrated as a relatively even distribution across age groups, higher in male participants (8.0%) than in female participants, and more frequent in patients with lumbar surgical lesions (8.2%) than without surgical lesions. Whereas, the prevalence of thoracic HLFS tended to increase with age, was higher in female participants (21.6%) than in male participants, and had no association with presence of lumbar surgical lesions. The most frequently involved segments of TDH and HLFS were T8/9 and T10/11, respectively. Six of 145 patients with TDH and 15 of 421 patients with HLFS underwent surgery.

CONCLUSIONS

The prevalence of TDH had a significant association with the presence of lumbar surgical lesions and no association with age. The prevalence of thoracic HLFS had a strong association with age and no association with lumbar surgical lesions.

THORACIC DISC HERNIATION: CASE SERIES AND PROTOCOL FOR SURGICAL APPROACHES

ABSTRACT Objective To describe the surgical results of a prospective series of five patients operated according to an approach indication protocol. Methods: Patients were classified according to surgical risk: Group A (high risk) or B (low risk) and subsequently into subgroups according to characteristics of the herniation and ultimately the surgical approach was defined: A.1) calcified central herniations - thoracoscopy; A.2) soft lateral herniations - posterolateral approach; A.3) centrolateral herniations - partial calcification in lateral position - posterolateral approach; higher density central calcification - thoracoscopy; B.1) central or centrolateral calcified herniations - thoracotomy or thoracoscopy; B.2) soft lateral herniations - posterolateral approach. Results: The duration of symptoms ranged from 2 months to 3 years; the age bracket was from 37 to 58 years; sex distribution was 3 female and 2 male patients and the length of hospital stay ranged from 2 to 20 days. The most affected level was T11/12. A patient classified as Group A.3 underwent posterolateral approach. The remaining patients were Group B.1, 3 submitted to thoracotomy and 1 to thoracoscopy. The herniation removal was completed in 5 cases; 3 patients improved and 2 remained stable. The morbidity and the recovery time were higher in patients who underwent anterolateral approaches. Conclusions: Classify patients according to surgical risk and the anatomical characteristics of disc herniation allows for complete decompression, minimizing morbidity and mortality.

Surgical management and clinical outcomes of multiple-level symptomatic herniated thoracic discs

Object

Symptomatic herniated thoracic discs (HTDs) are rare, and patients infrequently require treatment of 2 or more disc levels. The authors assess the surgical management and outcomes of patients with multiple-level symptomatic HTDs.

Methods

A retrospective review of a prospectively maintained database was performed of 220 consecutive patients treated surgically for symptomatic HTDs. Clinical and surgical results were compared between patients with single-level disease and patients with multiple-level disease and also among the different approaches used for surgical decompression.

Results

Between 1992 and 2012, 56 patients (mean age 48 years; 26 male, 30 female) underwent 62 procedures for 130 HTDs. Forty-six patients (82%) had myelopathy, and 36 (64%) had thoracic radiculopathy; 24 patients had both conditions in varying degree. Symptom duration averaged 28 months. The surgical approach was dictated by disc size, consistency, and location. Twenty-three thoracotomy, 26 thoracoscopy, and 13 posterolateral procedures were performed. Five patients required a combination of approaches. Patients underwent 2-level (n = 44), 3-level (n = 7), 4-level (n = 4), or 5-level (n = 1) discectomies. Instrumented fusion was performed in 36 patients (64%). Thirteen patients harbored 19 additional discs, which were deemed asymptomatic/nonoperative.

The mean hospital stay was 6.5 days. Complete disc resection was verified with postoperative imaging in every patient. The procedural complication rate was 23%, and the nature of complications differed based on approach. No patients had surgery-related spinal cord injury or new myelopathy.

At a mean follow-up of 48 months, myelopathy and radiculopathy had resolved or improved at a rate of 85% and 92%, respectively. Using a general linear model, preoperative symptom duration (p = 0.037) and perioperative hospital length of stay (p = 0.004) emerged as negative predictors of myelopathy improvement. Most patients (96%) were satisfied with the surgical results.

Compared with 164 patients who underwent single-level HTD decompression, patients requiring surgery for multiple-level HTDs were more often myelopathic (p = 0.012). Surgery for multiple-level HTDs was more likely to require a thoracotomy approach (p = 0.00055) and instrumented fusion (p < 0.0001) and resulted in greater blood loss (p = 0.0036) and higher complication rates (p = 0.0069). The rates of resolution for myelopathy (p = 0.24) and radiculopathy (p = 1.0), however, were similar between the 2 patient groups.

Conclusions

The management of multiple-level symptomatic HTDs is complex, requiring individualized clinical decision making. The surgical approaches must be selected to minimize manipulation of the compressed thoracic spinal cord, and a patient may require a combination of approaches. Excellent surgical results can be achieved in this unique and challenging patient population.

Surgical management of multiple thoracic disc herniations via a transfacet approach: a report of 15 cases

OBJECTIVE

Symptomatic thoracic disc herniations (TDHs) are rare, and multiple TDHs account for an even smaller percentage of symptomatic herniated discs. Most TDHs are found in the lower thoracic spine, with more than 75% occurring below T-8. The authors report a series of 15 patients with multiple symptomatic TDHs treated with a modified transfacet approach.

METHODS

Fifteen patients (9 women and 6 men) with a total of 32 symptomatic TDHs were treated surgically at the authors' institution between 1994 and 2010. The average patient age was 51.1 years. Thirteen patients had 2-level herniation and 2 patients had 3-level disease. The most commonly involved level was T7-8 (10 herniations), followed by T6-7 and T8-9 (6 herniations each). All patients had long-standing myelopathic and/or radicular complaints at the time of presentation. Each disc that exhibited radiographically confirmed compression of the spinal cord or nerve root was considered for resection. Only patients with lateral disc herniations were considered for the modified transfacet approach; patients with a centrally herniated disc underwent ventral or ventral-lateral procedures. The average follow-up time was 30 months.

RESULTS

All patients had successful resection of their herniated discs. All patients with preoperative weakness demonstrated improved strength, and 11 of 12 patients with preoperative pain showed improvement in pain. Sensory loss was less consistently improved. The 2 patients who underwent posterior fixation and fusion achieved radiographically confirmed fusion by the 1-year follow-up. Nine of 10 patients who were working returned to their jobs. Eleven of 12 patients with preoperative back or radicular pain had drastic or complete pain resolution; 1 patient had no change in pain. All 7 patients with preoperative ambulatory difficulty had postoperative gait improvement. Complications were minimal.

CONCLUSIONS

Multiple symptomatic herniated thoracic discs are rare causes of pain and disability, but should be treated surgically because good outcomes can be achieved with acceptably low morbidity.

Experience in the surgical management of 82 symptomatic herniated thoracic discs and review of the literature

OBJECT

The authors aimed to develop management strategies for the treatment of herniated thoracic discs and to define indications for selection of surgical approaches. Symptomatic thoracic discs requiring surgery are rare. Between 1971 and 1995, 71 patients with 82 herniated thoracic discs were surgically treated by the authors. The treated group included 34 men and 37 women whose ages ranged from 19 to 75 years, with a mean age of 48 years. The most common sites of disc herniation requiring surgery were from T-8 to T-11. Evidence of antecedent trauma was present in 37% of the patients. Preoperative symptoms included pain (localized, axial, or radicular) in 54 (76%) of the 71 patients, evidence of myelopathy, that is, motor impairment in 43 (61%), hyperreflexia and spasticity in 41 (58%), sensory impairment in 43 (61%), and bladder dysfunction in 17 (24%).

METHODS

Radiological diagnosis for the patients in this series was accomplished by means of myelography, computerized tomography myelography, or magnetic resonance imaging. Classification of the disc location into two groups reveals that 94% were centrolateral and 6% were lateral. Evidence of calcification was present in 65% of patients, and in 7% intradural extension was noted at surgery. Ten patients (14%) were found to have multiple herniations. Four surgical approaches were used for the removal of these 82 disc herniations: transthoracic in 49 (60%), transfacet pedicle-sparing in 23 (28%), lateral extracavitary in eight (10%), and transpedicular in two (2%). Postoperative evaluation revealed improvement or resolution of pain in 47 (87%) of 54, hyperreflexia and spasticity in 39 (95%) of 41, sensory changes in 36 (84%) of 43, bowel/bladder dysfunction in 13 (76%) of 17, and motor impairment in 25 (58%) of 43. Complications occurred in a total of 12 (14.6%) of 82 discs treated surgically. Major complications were seen in three patients and included perioperative death from cardiopulmonary compromise, instability requiring further surgery, and an increase in the severity of a preoperative paraparesis.

CONCLUSIONS

Review of this series, with the attendant complications, together with evaluation of several contemporary thoracic disc series, has facilitated the authors' decision-making process when considering the comprehensive management of these patients, including the selection of a surgical approach.

Experience in the surgical management of 82 symptomatic herniated thoracic discs and review of the literature

Object

The authors aimed to develop management strategies for the treatment of herniated thoracic discs and to define indications for selection of surgical approaches. Symptomatic thoracic discs requiring surgery are rare. Between 1971 and 1995, 71 patients with 82 herniated thoracic discs were surgically treated by the authors. The treated group included 34 men and 37 women whose ages ranged from 19 to 75 years, with a mean age of 48 years. The most common sites of disc herniation requiring surgery were from T-8 to T-11. Evidence of antecedent trauma was present in 37% of the patients. Preoperative symptoms included pain (localized, axial, or radicular) in 54 (76%) of the 71 patients, evidence of myelopathy that is, motor impairment in 43 (61%), hyperreflexia and spasticity in 41 (58%), sensory impairment 43 (61%), and bladder dysfunction in 17 (24%).

Methods

Radiological diagnosis for the patients in this series was accomplished by means of myelography, computerized tomography myelography, or magnetic resonance imaging. Classification of the disc location into two groups reveals that 94% were centrolateral and 6% were lateral. Evidence of calcification was present in 65% of patients, and in 7% intradural extension was noted at surgery. Ten patients (14%) were found to have multiple herniations. Four surgical approaches were used for the removal of these 82 disc herniations: transthoracic in 49 (60%), transfacet pedicle-sparing in 23 (28%), lateral extracavitary in eight (10%), and transpedicular in two (2%). Postoperative evaluation revealed improvement or resolution of pain in 47 (87%) of 54, hyperreflexia and spasticity in 39 (95%) of 41, sensory changes in 36 (84%) of 43, bowel/bladder dysfunction in 13 (76%) of 17, and motor impairment in 25 (58%) of 43. Complications occurred in a total of 12 (14.6%) of 82 discs treated surgically. Major complications were seen in three patients and included perioperative death from cardiopulmonary compromise, instability requiring further surgery, and an increase in the severity of a preoperative paraparesis.

Conclusions

Review of this series, with the attendant complications, together with evaluation of several contemporary thoracic disc series, has facilitated the authors' decision-making process when considering the comprehensive management of these patients, including the selection of a surgical approach.

Thoracic disc disease: experience with the transpedicular approach in twenty consecutive patients

TWENTY CONSECUTIVE PATIENTS were treated for symptomatic thoracic disc herniation with the transpedicular approach. Most patients had severe, incapacitating local or radicular pain. Myelopathy was uncommon as magnetic resonance imaging allowed an early diagnosis. Computed tomography, after myelography, provided further information necessary for surgical planning. Three patients had disc disease at two levels. Nine central and 14 lateral disc herniations were found. Disc calcification or an associated osteophyte was identified in six instances. Although the size of the disc herniation correlated with the amount of cord compression, no radiological features were found to be correlated with neurological function. The transpedicular approach was used in all patients. New curettes, specifically designed for the procedure, allowed the removal of all discs, including central and calcified fragments. A modified arthroscope was used to confirm neural decompression in some instances. One year after surgery, all 20 patients were significantly improved and 8 patients were asymptomatic. Apart from the duration of the symptoms, no other factors were found to affect outcome. The findings suggest that the prognosis of thoracic disc herniation is excellent if the disease is recognized early. The transpedicular approach, using curettes specifically designed for the procedure, can be an effective and safe method of surgical decompression in carefully selected patients.

Multiple thoracic disc herniations

Multiple thoracic disc herniation is a rare disease. There are only 12 cases reported in the literature. They were treated surgically. Two cases of multiple thoracic disc herniations subjected to laminectomy without discectomy are presented in this report.

Prolapsed thoracic intervertebral disc: the importance of CT assisted myelography

We present six new cases of prolapsed thoracic intervertebral disc (PTIVD), and review the clinical and radiological features, particularly with regard to the role of computed tomography (CT) examination in the diagnosis and management. In patients with atypical lower limb pain, particularly when associated with sphincter disturbances, lumbar myelography is incomplete unless supplemented by an examination of the conus region and lower thoracic cord. The supplementary use of CT in suspected PTIVD is of considerable value to the surgeon in determining the size, position, and volume of the sequestration, and the extent of excavation of the spinal cord by prolapsed disc material.

Current status of myelography in the evaluation of the thoracic spinal cord

The myelographic features in 35 patients with clinical thoracic spinal cord disease and normal plain radiographs were reviewed to re-evaluate the role of pre-operative myelography since the advent of computed tomography and magnetic resonance. The most frequent lesions were meningioma (9 cases), prolapsed intervertebral disc (9 cases), and metastases (8 cases). The extent and anatomical location of the lesion was demonstrated in all 19 patients without myelographic block. In 16 cases with complete block, the anatomical location was demonstrated in 14, and the extent of the lesion in four, using cervical puncture in two and CT myelography in one. Myelography remains a valuable method of assessment of the thoracic spinal cord and canal and is sufficient to allow the preoperative planning of surgical management in the absence of complete block. Additional investigation by computed tomography or magnetic resonance imaging is advised in the presence of complete block or an intramedullary lesion.

'Benign thoracic pain' syndrome: role of magnetic resonance imaging in the detection and localization of thoracic disc disease

The syndrome of 'benign thoracic pain' is seen in young women who have pain and tenderness in the mid-thoracic spine radiating around the chest and aggravated by spinal movement. Ten consecutive patients with this syndrome and 15 controls were evaluated with magnetic resonance imaging (MRI). This showed thoracic intervertebral disc dehydration with no associated prolapse in 90% of the patients and 13% of the controls. We postulate that the clinical features are due to impaired shock absorption of these degenerate discs rather than direct compression of surrounding structures. MRI is non-invasive and does not use ionizing radiation; it allows direct visualization of the entire thoracic spine and cord, and accurate detection of early disc degeneration. Thus, it is the imaging modality of choice for defining the subtle intervertebral disc abnormalities that characterize the 'benign thoracic pain' syndrome.

Thoracic disc herniation versus spinal metastases: optimizing diagnosis with magnetic resonance imaging

Thoracic disc herniation has been difficult to diagnose, both on clinical grounds and by conventional radiologic methods. This entity may masquerade as a neoplastic mass, particularly if there is a history of primary malignancy. Magnetic resonance imaging was able to establish the correct diagnosis in each of the four cases presented here.