Thoracic Disc Disease Research Articles

Transthoracic discectomy without interbody fusion

Background Transthoracic discectomy is an established surgical procedure for the treatment of thoracic disk disease. Most authors advocate interbody fusion after transthoracic discectomy. The purpose of this study was to determine if there were any adverse consequences in foregoing interbody fusion after transthoracic discectomy. Methods Eighteen consecutive patients underwent transthoracic discectomy without fusion between 1996 and 2002 at Mayo Clinic (Rochester, MN). There were 11 women and 7 men with the mean age of 54 years (range, 28-84 years). Surgical indications were radiculopathy in 1 patient and myelopathy in 17. Follow-up data were obtained from the clinic visits and telephone surveys. We used the available pre- and postoperative radiographs for 16 patients at the last follow-up to establish the incidence of postoperative kyphosis and/or scoliosis at the operated level. Mean duration of the radiographic follow-up was 22 ± 24 (SD) months. Results None of the patients reported the onset of a new axial spine pain postoperatively. No patient developed segmental kyphosis or scoliosis at the operated level during the follow-up period. Fifteen of 18 (83%) patients had significant improvement in their neurological symptoms and signs. Two patients remained unchanged. An 83-year-old patient had a slight worsening of her gait after surgery. Specifically, the only 3 nonambulatory patients regained ambulation after discectomy. There were 4 complications: 1 wound infection, 1 pleural effusion requiring pleurodesis, 1 cerebrospinal fluid leak, and 1 case of disabling intercostal neuralgia. Conclusions These results indicate that interbody fusion may not be necessary for selected patients undergoing transthoracic discectomy. Further long-term follow-up is needed to evaluate the development of late spinal instability and resultant deformity after this procedure.

Thoracic spine disc-related abnormalities: longitudinal MR imaging assessment.

To describe and characterize the temporal changes in disc-related disorders of the thoracic spine using MR imaging. A retrospective longitudinal cohort study was carried out of 40 patients with two sequential thoracic spine MR images at variable intervals. The images were assessed for baseline presence of, new incidence of and changes in disc herniation, degenerative disc disease, endplate marrow signal alteration and Schmorl nodes. The range of follow-up was 4-149 weeks. Baseline presence was: disc herniation, 10% (49/480); degenerative disc disease, 14% (66/480); endplate marrow signal alteration, 2.3% (11/480); Schmorl nodes 9.6% (46/480). Most pre-existing lesions tended to remain unchanged. Herniations showed the most change, tending to improve in 27%. New incidence was: disc herniation, 1.5% (7/480), degenerative disc disease, 2% (10/480); endplate marrow signal alteration, 1.6% (8/480); Schmorl nodes, 2.1% (10/480). Disc degeneration was first visible at an 11-week interval and once established almost never changed over many weeks to months. Endplate signal alterations (Modic changes) were uncommon. Schmorl nodes show no change from baseline for up to 2 1/2 years. All findings predominated in the lower intervertebral levels from T6 to T10. The most prevalent thoracic spine disc-related findings are degeneration and herniation. Disc herniations predominate in the lower segments and are a dynamic phenomenon. Disc degeneration can be rapidly evolving but tends to remain unchanged after occurrence. Endplate marrow signal changes were an uncommon manifestation of thoracic disc disease. Schmorl nodes showed the least change over time.

Posterolateral thoracic disc disease: clinical presentation and surgical experience with a modified approach

Posterolateral thoracic disc disease is often misdiagnosed and labelled as demyelination. A high index of suspicion and awareness of this disease entity is the key to diagnosis and treatment. Our experience with a modified posterolateral facetal-sparing pedicle-sparing approach is highlighted.

Upper thoracic-spine disc degeneration in patients with cervical pain.

To study the relationship of upper thoracic spine degenerative disc contour changes on MR imaging in patients with neck pain. The relation between upper thoracic and cervical spine degenerative disc disease is not well established. One hundred and fifty-six patients referred with cervical pain were studied. There were 73 women and 77 men with a mean age of 48.6 +/- 14.6 years (range, 19 to 83 years). All MR studies were performed with a large 23-cm FOV covering at least from the body of T4 to the clivus. Discs were coded as normal, protrusion/bulge or extrusion. Degenerative thoracic disc contour changes were observed in 13.4% of patients with cervical pain. T2-3 was the most commonly affected level of the upper thoracic spine, with 15 bulge/protrusions and one extrusion. Upper degenerative thoracic disc contour changes presented in older patients than the cervical levels (Student-Newman-Keuls test, P < 0.001). Degenerative disc contour changes at the C7-T1, T1-2, T2-3 and T3-4 levels were significantly correlated ( P = 0.001), but unrelated to any other disc disease, patient's gender or age. Degenerative cervical disc disease was closely related together ( P < 0.001), but not with any thoracic disc. A statistically significant relation was found within the upper thoracic discs, reflecting common pathoanatomical changes. The absence of relation to cervical segments is probably due to differences in their pathomechanisms.

Video-Assisted Thoracoscopic Surgery for Thoracic Disc Disease

Prospectively collected data from regular clinical follow-up evaluations were tabulated, analyzed, reviewed using a patient self-reported questionnaire. To develop a classification system and present the long-term functional outcome of video-assisted thorascopic surgery for refractory thoracic disc disease. Recent studies have found an 11.1% to 14.5% prevalence of thoracic disc herniations. Surgical approaches have included laminectomy, pediculectomy, costotransversectomy, lateral extracavitary, transverse arthropediculectomy, transthoracic-transpleural thoracotomy, and thoracoscopy. Recent reports have documented encouraging early results with video-assisted thorascopic surgery for thoracic disc herniations. Comparisons between thoracoscopy and open thoracotomy have demonstrated improvement in postoperative pain and morbidity with the use of endoscopic techniques. This study included 100 consecutive patients (45 women and 55 men) with an average follow-up evaluation of 4 years (range, 2-6 years). The average age of the patients was 42 years (range, 22-76 years). The average duration of symptoms was 26 months (range, 6-96 months), and 18 patients had undergone prior spine surgery. Patients were graded as follows according to the presenting symptoms (Table 1): Grade 1 (pure axial; n = 28), Grade 2 (pure radicular; n = 5), Grade 3A (axial and thoracic radicular; n = 38), Grade 3B (axial with lower leg pain; n = 19), Grade 4 (myelopathic; n = 8), or Grade 5 (paralytic = 2). A total of 117 discs were excised in 100 patients. Of the 40 patients who underwent fusion, 27 had autologous rib struts and 13 had threaded fusion. The mean operative time was 173 minutes, blood loss 259 mL, average ICU stay less than 1 day, and average hospital stay 4 days. Minor complications occurred in 21 patients, all of which resolved with no untoward effect. No patient's neurologic status worsened. Four patients underwent a secondary fusion, and a pseudarthrosis developed in one patient. Clinical success was defined objectively as an improvement in Oswestry score of 20% or more at 2 years and at final follow-up assessment, as compared with the preoperative Oswestry score. Overall, objective clinical success was observed at 2 years in 73% of the patients, and at final follow-up assessment in 70% of patients. The average percentage of improvement in Oswestry scores was most marked in Grade 4 patients (myelopathy; 60%), followed by Grade 3A patients (axial and thoracic radicular pain; 37%), Grade 3B patients (axial with leg pain; 28%), and Grade 1 patients (pure axial; 24%). The Oswestry disability score (Table 2) and back pain visual analog score (Table 3) also were significantly improved (P < 0.05) at 2 years and at final follow-up assessment in these patients. In the Grade 2 patients, those pure thoracic radicular pain, Oswestry scores initially improved significantly up to 1 year (P < 0.05). At 2 years, no significant improvement could be shown, and four of the five Grade 2 patients reported increased axial pain as their main symptom at the final follow-up assessment. Significant improvement also was seen in patients with no prior spine surgery and patients with preoperative Oswestry disability scores greater than 50. Of the 68 patients who responded to the final questionnaire, 12 rated the procedure as excellent, 37 as good, 11 as fair, and 8 as poor. Also, 57 (83.8%) of these 68 patients were satisfied and indicated they would recommend the surgery. Of the 36 patients at the final follow up assessment who had severe disability, 34 (94%) were satisfied, as compared with 23 of the 32 patients (72%) who had presented with milder disability. The clinical classification system helps in differentiating different presentations of thoracic disc disease and their final outcome. Video-assisted thorascopic surgery appears to be a safe and efficacious method for the treatment of refractory symptomatic thoracic disc herniations. The current data suggest that the procedure has an acceptable long-term outcome, with an 84% overall subjective patient satisfaction rate, and with objective long-term clinical success achieved in 70% of patients.

Concomitant lower thoracic spine disc disease in lumbar spine MR imaging studies.

Our objective was to study the coexistence of lower thoracic-spine disc changes in patients with low back pain using a large field of view (FOV) in lumbar spine MR imaging. One hundred fifty patients with low back pain were referred to an MR examination. All patients were studied with a large FOV (27 cm), covering from the coccyx to at least the body of T11. Discs were coded as normal, protrusion, and extrusion (either epiphyseal or intervertebral). The relationship between disc disease and level was established with the Pearson chi(2) test. The T11-12 was the most commonly affected level of the lower thoracic spine with 58 disc cases rated as abnormal. Abnormalities of T11-12 and T12-L1 discs were significantly related only to L1-L2 disease ( p=0.001 and p=0.004, respectively) but unrelated to other disc disease, patient's gender, and age. No correlation was found between other discs. Magnetic resonance imaging of the lumbar spine can detect a great amount of lower thoracic disease, although its clinical significance remains unknown. A statistically significant relation was found within the thoracolumbar junctional region (T11-L2), reflecting common pathoanatomical changes. The absence of relation with lower lumbar spine discs is probably due to differences in their pathomechanisms.

Endoscopic instrumentation, correction, and fusion of idiopathic scoliosis

Background context: Endoscopic techniques have been used since 1993 to treat thoracic disk disease. Thorascopic techniques evolved into means of treating not only disk disease but also correcting thoracic spinal deformity with instrumentation and fusion. Purpose: To evaluate the efficacy of endoscopic instrumentation, correction, and fusion of thoracic idiopathic scoliosis. Study design: A retrospective review of 50 patients who have undergone endoscopic instrumentation, correction, and fusion for scoliosis. Patient sample: Fifty consecutive patients undergoing treatment for primary thoracic idiopathic scoliosis. Outcome measures: Evaluation of operative time, curve correction, and fusion rates were evaluated. Methods: Fifty patients with the diagnosis of primary thoracic scoliosis underwent thoracoscopic techniques of instrumentation, correction, and fusion. On follow-up, the patients were evaluated for spinal alignment restoration, axial derotation, postoperative pain, rehabilitative time, and complications. Results: The initial curve correction averaged 50%, improving to over 68% in the last 10 cases. Hypokyphosis correction averaged 21 degrees. Additionally, there has been a decrease in rehabilitation time, less time off work or school, and decreased blood loss and postoperative pain. There were 14 complications and no deaths recorded. The factors involved in a successful fusion include total diskectomy, complete cartilaginous end plate removal, and autogenous bone graft. Conclusions: The initial results of the thoracoscopic-assisted techniques for primary thoracic scoliosis are promising. As with most evolving techniques, surgical times are decreasing and rates of correction are improving.

Retropleural thoracotomy

Herniated thoracic discs, unlike their lumbar counterparts, are difficult to read and safely resect using traditional posterior approaches. Historically, the use of a laminectomy for thoracic disc resection has yielded poor clinical outcomes. Posterolateral and anterolateral approaches have become the standard surgical means of treating these lesions. The traditional anterolateral approach, the transpleural thoracotomy, is an extensive procedure that requires direct retraction of the lung, a deep surgical field, and postoperative closed-chest drainage. An alternative to this anterior approach, the retropleural thoracotomy, is described here. This approach provides the shortest direct route to the thoracic spine and leaves the pleura intact. A smaller incision and less retraction than traditional approaches may reduce postoperative pain and pulmonary-related complications. The retropleural thoracotomy is a valuable technique for the neurosurgeon treating thoracic disc disease.

Surgery for thoracic disc disease. Complication avoidance: overview and management

The operative approach for discectomy in the treatment of thoracic disc disease has changed from standard laminectomy to a variety of dorsolateral and ventral approaches. The procedure-related complications have been reported in numerous clinical studies over the last seven decades: death, neurological deterioration, postoperative vertebral column instability, incomplete disc resection, cerebrospinal fluid leak and fistula, infection, misdiagnosis, pulmonary embolism, pneumonia, and intercostal neuralgia. The authors conducted a Medline search to identify series reporting clinical data related to thoracic discectomy. They analyzed the morbidity and mortality resulting from the various surgical approaches for thoracic disc disease, with special attention to the avoidance and management of surgery-related complications.

Artificial disc technology

After approximately 40 years of research and development, artificial disc technology may finally be coming of age. A number of devices are either at the late stage of preclinical study or in the early stage of clinical trial, and the results are promising so far. Due to the multicomponent structure of the disc, surgeons performing disc arthroplasty have the option of replacing either the entire disc or a portion of it. The decision will be largely dependent on the pathological entity addressed, the condition of the patient's spinal disc and surrounding tissues, and the cost and potential risk of the procedure. Driven by demand, almost all the emphasis in artificial disc development has been placed on the lumbar disc, with a smaller effort directed toward the cervical disc. No attempt has been made to develop an artificial thoracic disc. However, by examining the differences and similarities in structure, anatomy, function, mechanism of degeneration, pathology, surgical technique, and complications between the lumbar and thoracic disc, the authors believe it is feasible to apply artificial disc technology in the treatment of thoracic disc disease. Nonetheless, due to the rarity of thoracic disc disease and the more stable structure of this spinal component, the demand for artificial disc or artificial nucleus technology for the thoracic disc probably will be smaller than that for lumbar disc technology.

Thoracoscopic surgery: historical perspectives

Recent technical advances have revolutionized the fields of surgical endoscopy, laparoscopy, thoracoscopy, and microsurgical spinal endoscopy. The authors discuss the rich history and recent evolution of these techniques. Thoracoscopy had been widely used for the treatment of pleural conditions associated with tuberculosis. It was largely abandoned in the 1950s when effective antituberculosis medications were introduced. In the 1980s the development of video-assisted endoscopic procedures in the fields of general surgery, orthopedics, and otolaryngology provided new impetus to revive thoracoscopy. As a result of these advances thoracoscopy replaced open thoracotomy in many cardiothoracic procedures. These improvements led to the application of these techniques to treat disorders of the spine. By the mid-1990s microsurgical endoscopy was being used effectively to treat thoracic disc disease, perform anterior surgical release procedures for scoliosis, resect tumors, and even to conduct complex spinal fusions and reconstructions. As technology continues to improve, there is no doubt that thoracoscopic surgery will find a permanent place in the armamentarium of techniques used to treat pathological entities of the spine.

The pathophysiology of thoracic disc disease

Nucleus pulposus herniations are far less common in the thoracic spine than at the cervical and lumbar regions. Traditionally, diagnosis of thoracic disc herniations has been challenging because the signs and symptoms are often subtle early in their course. As a result, delays in diagnoses are common. Because they are uncommon as well as difficult to diagnosis, the neurosurgical community has sparse data on which to base good clinical decision making for the treatment of these herniations. In this review the authors seek to place the phenomenon of thoracic disc disease into the context of its pathophysiology. After a careful evaluation of the available clinical, pathological, and basic science data, a case is made that the cause of nucleus pulposus herniations in the thoracic spine is similar to those occurring in the lumbar and cervical regions. The lower incidence of herniations is ascribed primarily to the reduced allowable flexion at the thoracic level compared with the lumbar and cervical levels. To a lesser extent, the contribution of the ribs to weight-bearing may also play a role. Further review of clinical data suggests that thoracic disc herniations, like herniated cervical and lumbar discs, may be asymptomatic and may respond to conservative therapy. Similarly, good surgery-related results have been reported for herniated thoracic discs, despite the more challenging nature of the surgical procedure. The authors conclude that treatment strategies for thoracic disc herniations may logically and appropriately follow those commonly used for the cervical and lumbar levels.

Imaging-guided costotransversectomy for thoracic disc herniation

The surgical management of thoracic disc disease remains challenging. Outcomes after laminectomy had been poor, and modern posterolateral, lateral, and anterior approaches have evolved to replace this older procedure. Each has its own set of complications, and all are hampered, to varying degrees, by the limited visualization of the ventral disc space and spinal cord during decompression. The authors present their early experience with computer-assisted image guidance as an adjunctive tool for preoperative planning and navigation in the treatment of thoracic disc disease. Five consecutive patients underwent image-guided costotransversectomies between January 1999 and April 2000. The levels of herniation were T8-9 in three and T7-8 and T5-6, respectively, in the other two. There were four centrolateral herniations and one midline herniation. Three discs were soft and two hard. Two patients had previously undergone failed disc excisions. All patients had axial pain and myeloradiculopathies preoperatively. Three were unable to walk. Four patients enjoyed good or excellent outcomes, with return of ambulation. One patient experienced only mild improvement in her severe paraparesis. Image-guidance was invaluable in planning the corpectomy and aiding visualization in situations in which the dura or disc were obscured; its use allowed successful surgical excisions in the most challenging circumstances.

Thoracic disk disease: diagnosis and treatment.

Symptomatic degenerative disk disease is much less common in the thoracic spine than in the cervical and lumbar regions. Accurate diagnosis relies on a strong clinical suspicion that is confirmed with appropriate diagnostic imaging. Presenting symptoms vary tremendously, from atypical pain patterns to myelopathy. The use of computed tomography in combination with myelography and magnetic resonance imaging have greatly increased the ability to accurately visualize thoracic spine disorders. The superior resolution of available imaging modalities has made the incidental detection of asymptomatic thoracic disk abnormalities more frequent. Most patients with symptomatic thoracic disk disease will respond favorably to nonoperative management. Surgery is indicated for the rare patient with an acute thoracic disk herniation with progressive neurologic deficit (i.e., signs or symptoms of thoracic spinal cord myelopathy). Once surgical intervention has been chosen, careful preoperative planning is necessary. The level, anatomic location, and morphology of the herniation must be precisely determined to select the optimal approach. Posterior laminectomy has largely been abandoned for the treatment of symptomatic thoracic disk protrusions. Surgeons still may choose among anterior, lateral, and posterior approaches when surgically addressing the thoracic intervertebral disk.

Review: Complications of Surgery For Thoracic Disc Disease

Background Thoracic discectomy has evolved over the last 60 years from resection through standard laminectomy, to posterolateral procedures to open thoracotomy and finally thoracoscopy. Comparison of relative morbidity and mortality between these approaches is now possible. Methods Peer-reviewed publications reporting clinical data relating to thoracic discectomy, and which provided sufficient information to enable adequate assessment of mortality and morbidity were reviewed. These articles were determined via review of the results of MedLine searches and articles gathered through compilation of references from those articles. Results Articles reviewed spanned a period of over 60 years. Surgical procedures used for thoracic discectomy included laminectomy, pediculectomy, costotransversectomy, lateral extracavitary, transverse arthropediculectomy, anterolateral thoracotomy, and thoracoscopy. Complications included death, paralysis, paresis, loss of bowel and/or bladder control, pulmonary embolism, pneumonia, atelectasis, compression fracture, infection, pleural tear, bowel obstruction, and anesthesia dolorosa. Mortality dropped to nearly zero after development of anterior and posterolateral approaches. Morbidity seems relatively similar between most procedures other than laminectomy. Not enough procedures have been reported using thoracoscopy to adequately assess its morbidity. Conclusion Comparison of relative rates of morbidity and mortality between surgical approaches to thoracic discectomy suggest that laminectomy does not provide adequate access for the safe removal of these lesions. Choice of approach among the alternatives should be based on the evacuation of the herniated fragment and experience of the surgeon. Thoracoscopy, although promising, has not had sufficient time for evaluation of morbidity to make definite statements regarding its safety.

Thoracoscopic exposure of intervertebral discs

Video-assisted thoracic surgical techniques provide access to the anterior thoracic spine without the morbidity of open thoracotomy. Improved diagnostic methods now give better awareness of the incidence and clinical significance of thoracic herniated nucleus pulposus. We present video-assisted thoracic surgical exposure techniques that have been used successfully to treat thoracic disc disease from T-2 to T-12.

Thoracic disk disease

Thoracic disk disease

Thoracic Disc Herniations

Because of the protean nature of thoracic disc disease, surgeons should maintain a high order of suspicion of a thoracic disc herniation in the patient with unexplained localized back or torso pain and sensorimotor deficits. These patients should have MR imaging performed as a screening test, and, if suspicious for a thoracic disc herniation, confirmatory myelogram and postmyelogram CT imaging. Though the natural history is anecdotal, there appears to be a tendency for myelopathic symptoms and signs to be progressive, warranting surgical intervention. For radicular dysfunction or localized back pain, a conservative therapeutic plan is recommended. If intractable pain is demonstrated, and the diagnosis is certain, then surgical intervention is recommended. Once surgical intervention is recommended the surgical approach needs to be individualized according to the surgeon's skills and experience and the specifics of the patient's pathology. Appropriate surgical decision-making depends on an understanding of the variety of surgical options and their advantages and disadvantages, and an understanding of the biomechanical factors of the spine of the individual patient. Surgical concepts important to successful thoracic disc removal are (1) minimal spinal cord manipulation, (2) preservation of the neurovascular supply whenever possible, (3) minimal manipulation of the intercostal nerve, and (4) preservation of maximal bony and ligamentous attachments allowable for adequate exposure. Lastly it is recommended that the posterior longitudinal ligament be removed to ensure complete spinal cord decompression.

Thoracic Disc Disease and Stenosis

Disc herniation and stenosis in the thoracic spine are relatively uncommon compared with their occurrence in the cervical or lumbar spine. They are usually degenerative, although trauma may be an aggravating or initiating factor. The clinical presentation includes local and/or radicular pain with or without signs and symptoms of cord dysfunction. Radicular pain may be secondary to mechanical compression or vascular impingement. MR imaging is the best way to define the specific abnormality as well as the effect on the adjacent spinal cord. CT after myelography may be useful as well, especially in those patients in whom there is involvement of the posterior ligamentous and osseous structures of the thoracic spinal canal. MR imaging may finally reveal the true incidence of thoracic disc herniation.

'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.