Transthoracic removal of midline thoracic disc protrusions causing spinal cord compression

Thoracoscopic microdiscectomy

The thorascopic approach for the microsurgical removal of herniated thoracic discs is described, and perioperative management is also discussed. The microsurgical techniques used for decompression of the spinal canal in the thoracic spine are presented in detail. The diagnostic imaging, surgical positioning, approach, port placement, localization of the thoracic level, exposure of the surgical field, excision of the rib head, exposure with removal of the herniated disc, and postoperative management are outlined. Surgical and operative "pearls" in thoracoscopic spinal surgery for removing herniated thoracic discs when possible are described and illustrated.

Symptoms of thoracolumbar junction disc herniation

STUDY DESIGN

A retrospective clinical review of patients with thoracolumbar junction disc herniation.

OBJECTIVES

To evaluate the clinical features of thoracolumbar junction disc herniation and to prepare a chart for the level diagnosis in the neurologic findings and symptoms.

SUMMARY OF BACKGROUND DATA

Thoracolumbar junction disc herniations show a variety of signs and symptoms because of the complexity of the upper and lower neurons of the spinal cord, cauda equina, and nerve roots. Furthermore, much is still unknown about thoracolumbar junction disc herniations because of their rare frequency.

METHODS

The clinical features of 26 patients who had undergone operations for single disc herniations at T10-T11 through L2-L3 were investigated. Affected levels were as follows: 2 patients with disc herniation at T10-T11 disc, 4 patients at T11-T12, 3 patients at T12-L1, 6 patients at L1-L2, and 11 patients at L2-L3. The level of disc space of interest was confirmed with whole-spine plain roentgenograms. The caudal end of the cord was judged by magnetic resonance imaging and computed tomographic myelogram.

RESULTS

Two patients with T10-T11 disc herniation showed moderate lower extremity weakness, increased patellar tendon reflex, and sensory disturbance of the entire lower extremities. Three of four patients with T11-T12 disc herniation experienced lower extremity weakness, and three patients had accentuated patellar tendon reflex. Sensory disturbance was observed in the anterolateral aspect of the thigh in one patient and on the entire leg in three patients. Bowel and bladder dysfunction was noted in three patients. In the T12-L1 disc herniation group (n = 3), muscle weakness and atrophy below the leg were advanced, and bowel and bladder dysfunction were also noted. Two of these three patients had bilateral drop foot, and one patient had unilateral drop foot; sensory disturbance was noted in the sole or foot and around the circumference of the anus, and the patellar tendon reflex and Achilles tendon reflex were absent. All six patients with L1-L2 disc herniation showed severe thigh pain and sensory disturbance at the anterior aspect or lateral aspect of the thigh. On the other hand, there were no clear signs of lower extremity weakness, muscle atrophy, deep tendon reflex, or bowel and bladder dysfunction in these patients. In the L2-L3 disc herniation group (n = 11), all patients had severe thigh pain and sensory disturbance of the anterior aspect or the lateral aspect of the thigh. Weakness in the quadriceps was noted in five patients and weakness in the tibialis anterior in two patients. Decreased or absence of patellar tendon reflex was observed in nine patients. Five patients had positive straight leg raising test results, and eight patients showed positive femoral nerve stretch test results.

CONCLUSION

Among thoracolumbar junction disc herniations, T10-T11 and T11-T12 disc herniations were considered upper neuron disorders, T12-L1 disc herniations were considered lower neuron disorders, L1-L2 disc herniations were considered mild disorders of the cauda equina and radiculopathy, and L2-L3 disc herniations were considered radiculopathy. These findings had relatively distinct differences among herniated disc levels.

Biomechanics of thoracic discectomy

The thoracic spine is a structurally unique region that renders it uniquely suceptible to thoracic disc herniation. Surgical management strategies are complicated, in part, by the regional anatomical and biomechanical nuances. Surgical approaches include posterior, posterolateral, and anterior routes. Each isassociated with specific indications and contraindications. The biomechanical principles and safe anatomical trajectories must be considered in the surgical decision-making process. These issues are discussed in the pages that follow.

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.

Transcostovertebral approach for thoracic disc herniations

OBJECT

The authors describe a new posterolateral transcostovertebral approach for the removal of herniated thoracic discs.

METHODS

From January 1994 to January 2000, 28 thoracic discs in 22 patients were excised via a new transcostovertebral surgical approach. Seventeen patients (77%) presented with axial pain, 14 (64%) with radicular pain, 13 (59%) with myelopathy, eight (36%) with sensory loss, and 10 (45%) with genitourinary (GU) symptoms such as urinary hesitancy or incontinence. The affected discs were approached using a midline incision to gain access of the costovertebral junction. The surgical corridor was posterolateral; the costovertebral joint and lateral edge of the vertebral endplates were drilled to expose the lateral annulus. The ribs were preserved, obviating the need for insertion of a chest tube postoperatively. The average operating time per level was 200.5 minutes (range 90-360 minutes). The average blood loss was 231 ml (50-750 ml). The average length of stay was 3.8 days. Most patients were discharged home on postoperative Day 2 or 3. No patients were worse postoperatively. Improvement was demonstrated in 13 (76%) of 17 patients with axial pain, 11 (79%) of 14 patients with radicular pain, 11 (85%) of 13 patients with myelopathy, seven (88%) of eight patients with sensory loss, and six (60%) of 10 patients with GU symptoms.

CONCLUSIONS

This procedure is well suited for any thoracic disc level and offers several advantages over the traditional costotransversectomy or transthoracic approaches: shorter operating time, less blood loss, less extensive soft-tissue and bone dissection, reduced postoperative pain, and shorter hospital stays.

Treatment of thoracic disc herniation: evolution toward the minimally invasive thoracoscopic technique

Thoracic disc herniation has always carried with it the potential for serious adverse neurological consequences if not treated appropriately. The authors review the historical evolution of treatment for thoracic disc herniation from the early surgical series using dorsal approaches (which were known to involve a significant risk of paraplegia) to later surgical series in which lateral and then ventral approaches to the disc were increasingly emphasized, with significant improvement in patient outcome. The evolution of minimally invasive thoracoscopic techniques is discussed, together with the results of several surgical series demonstrating significant reductions in morbidity compared with more traditional methods. The technique of thoracoscopic discectomy is presented in detail.

Laminotomy/medial facet approach in the excision of thoracic disc herniation

OBJECT

The author describes a technique of thoracic discectomy that has evolved from the posterolateral transfacet and the transpedicular approaches but that spares the pedicle and most of the facet joint.

METHODS

This approach was used to remove a total of 11 discs (T6-12) in seven patients. The follow-up period ranged from 8 months to 3 years. In four patients with axial and/or girdle pain significant improvement was demonstrated. The paraparesis in one patient with myelopathy improved postoperatively; that in another patient improved but recurred 8 months postoperatively. In one patient who experienced preoperative leg weakness, the weakness was slightly increased postoperatively, but this sequela was only transient. There were no other complications, and there were no deaths.

CONCLUSIONS

This technique appears safe and effective. It can be adapted to the conventional laminectomy known to spine surgeons and requires no specialized instruments. Further trials appear warranted.

Transpedicular approach for thoracic disc herniations

OBJECT

Patients with symptomatic herniated thoracic discs may require operation for intractable radiculopathy or functionally disabling myelopathy. In the past, laminectomy was the procedure of choice for the treatment of thoracic herniations, but it was found that the approach was associated with an unacceptably high rate of neurological morbidity. Several strategies have been developed to excise the disc without manipulating the spinal cord. The focus of this paper is the transpedicular approach.

METHODS

The author retrospectively reviewed the cases of 20 consecutive patients presenting with herniated thoracic discs in whom surgery was performed via a transpedicular approach. Fourteen patients presented with acute myelopathy and six with radiculopathy. Of those with myelopathy six of six regained ambulation and six of seven regained normal bladder function. No patient with myelopathy experienced neurological worsening. In four patients presenting with radiculopathy postoperative pain resolved, and in two it remained unchanged. Three minor complications (15%) occurred. No patient suffered postoperative spinal instability-related pain or delayed kyphosis.

CONCLUSIONS

As experience accumulates in the use of multiple approaches for the treatment of thoracic disc herniations, the role of each is becoming more clearly defined. The transpedicular approach is most applicable to lateral or centrolateral calcified or soft discs. The more anterior (transthoracic or thoracoscopic) and lateral (costotransversectomy or lateral extracavitary) approaches may be more useful for excision of central calcified discs.

Transthoracic approaches to thoracic disc herniations

The transthoracic approach to herniated thoracic discs is an important procedure in the management of these uncommonly encountered lesions. Whereas posterior and posterolateral microsurgical approaches and thoracoscopic procedures have been widely advocated in the recent neurosurgical literature, the transthoracic operation continues to offer significant advantages in appropriately selected cases. The authors discuss the preoperative considerations, relevant anatomical structures, and surgical technique.

Endoscopic transpedicular thoracic discectomy

Object

To reduce the invasiveness and risk of thoracic disc surgery, a transpedicular endoscopic approach has been created. The surgical technique and outcome of endoscopic transpedicular thoracic discectomy are reported.

Methods

The surgical technique of posterior transpedicular thoracic discectomy was modified to endoscopic transpedicular surgery. A 1.5-cm trocar was placed in the interlaminar space via a 2-cm transverse paramedian skin incision. At the ventral aspect of the spinal cord discectomy was performed under direct visualization by using a 70°-lens endoscope. This surgical technique was used in 25 patients. Twelve patients were men and 13 were women, aged 29 to 70 years (median 46 years). Myelopathy, with or without radiculopathy was present in 13 patients, radiculopathy in 10, and segmental pain in two. The follow-up periods ranged from 4 to 60 months (median 27 months).

In 12 of the 13 patients with myelopathy excellent improvement was shown postoperatively; the remaining patient suffered recurrence of symptoms after a motor vehicle accident three months postoperatively. In nine of the 10 patients with radiculopathy, pain was resolved completely. In one patient with right-sided hypochondral pain and two patients with segmental pain, relief was not achieved despite excellent results of discectomy demonstrated on postoperative magnetic resonance imaging. The average length of hospital stay was one night.

Conclusions

Endoscopic transpedicular thoracic discectomy was found to be a minimally invasive and effective surgical treatment.

Endoscopic thoracic discectomy

Object

Thoracoscopic discectomy is a minimally invasive procedure simulating a thoracotomy and is an alternative to the costotransversectomy and transpedicular approaches. In recent studies authors have concluded that thoracoscopic discectomy is the preferred procedure; however, relative historical comparisons were difficult to interpret.

The authors conducted a prospective nonrandomized study in which they compared data on 36 patients undergoing thoracoscopic discectomy with eight patients undergoing thoracotomy between 1995 and 1999.

Methods

Patients affected with one- or two-level lesions underwent a thoracoscopic discectomy, and patients with three-level lesions or more underwent thoracotomy and discectomy. Data were collected on operative time, blood loss, chest tube duration, narcotic agent use, and hospital length of stay (LOS). Longer-term follow-up study of pain-related symptoms and neurological function was conducted.

Patients who underwent thoracoscopic discectomy had shorter operative times, less blood loss, a shorter period of chest tube drainage dependence, less narcotic usage, and a shorter LOS. These findings were statistically significant (p < 0.05) for narcotic usage and shorter LOS. Pain related to radiculopathy was improved by means of 75%, and no patients exprienced worsened pain. In patients with myelopathy there was an improvement of two Frankel grades in the thoracoscopic group and one Frankel grade in the thoracotomy discectomy group, but patients in the thoracotomy group were significantly worse preoperatively. One myelopathic patient from each group suffered a worsened outcome postoperatively, although this was not attributed to the method of surgery. The incidence of complications (minor and major) was 31% in the thoracoscopic group and greater than 100% (that is, more than one complication per patient) in the thoracotomy/discectomy group.

Conclusions

One advantage to thoracoscopic discectomy is its reduced incidence of morbidity compared with thoractomy, but its steep learning curve and unfamiliar surgical techniques make this procedure less practical for surgeons not performing it frequently. The more familiar costotransversectomy, transpedicular, and thoracotomy procedures remain viable alternatives for surgeons more experienced in these procedures.

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.

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.

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.

Endoscopic transpedicular thoracic discectomy

OBJECT

To minimize the invasiveness and maximize the adequacy of the decompressive procedure in thoracic discectomy, a 70 degrees endoscope was adapted to perform transpedicular thoracic discectomy.

METHODS

A posterior transpedicular approach was performed via a 2-cm transverse skin incision, aided by an operating microscope or a 0 degrees lens endoscope. Using a 70 degrees lens endoscope, discectomy was performed after obtaining direct visualization of the ventral aspect of the spinal cord dura mater. This surgical technique has been used in 25 patients. There were 12 men and 13 women whose ages ranged from 29 to 74 years (median 46 years). Thirteen patients experienced myelopathy, with or without radiculopathy, 10 presented with radiculopathy, and two patients suffered from segmental pain. The follow-up period ranged from 4 to 60 months (median 27 months). In 12 of 13 patients with myelopathy, excellent improvement was shown postoperatively. In the remaining patient, symptoms recurred after she was injured in a motor vehicle accident 3 months postsurgery. In nine of 10 patients with radiculopathy, pain resolved completely. In the one patient with right-sided hypochondral pain and in the two patients with segmental pain, no relief was obtained despite excellent discectomy results demonstrated on postoperative magnetic resonance images. The average length of hospital stay was overnight.

CONCLUSIONS

The use of a 70 degrees lens endoscope through a transpedicular route has made thoracic discectomy comparable with cervical or lumbar discectomy in terms of minimal surgical invasiveness, recovery time, and complexity of the procedure.

Reoperation for herniated thoracic discs

OBJECT

In this review the authors address the surgical strategies required to resect residual herniated thoracic discs.

METHODS

Data obtained in 15 patients who had undergone prior thoracic discectomy and who harbored residual or incompletely excised symptomatic thoracic discs were reviewed retrospectively. The surgical procedures that had failed to excise the herniated discs completely included 11 posterolateral approaches, one thoracotomy, and three thoracoscopy-guided surgical procedures. Of the lesions that were incompletely resected or residual, there were 13 central calcified, two soft. 12 extradural, and three intradural discs. Indications for reoperation were often multiple in each patient and included misidentification of the level of disc disease at the initial operation (five cases), abandoning the procedure because of intraoperative spinal cord injury (three cases), inadequate visualization of the pathological entity (eight cases), migration of a soft disc fragment within the spinal canal (one case), and intradural disc extension (three cases). The symptoms at the time of reoperation included myelopathy in 13 patients and radicular pain in two patients. The mean interval before reoperation was 150 days (range 1 day-4 years). The reoperation procedures included one thoracotomy and 14 video-assisted thoracoscopic procedures performed ipsilateral (11 cases) or contralateral (four cases) to the site of the initial surgery. The herniated disc material was excised completely in all 15 cases without causing new neurological deficits. Reoperation complications included atelectasis in three patients, intercostal neuralgia in two, a loosened screw that required removal in one, residual intradural disc herniation that required a second reoperation in one patient, and a cerebrospinal fluid leak in one patient. Of the 13 patients who experienced myelopathy prior to operation, 10 recovered neurological function and three stabilized. All patients with radicular pain improved.

CONCLUSIONS

Calcified, large, broad-based, centrally located, or transdural thoracic disc herniations can be difficult to resect. These lesions require a ventral operative approach to visualize the dura adequately for a safe and complete resection.

[Transthoracic approach to the spinal column]

Thoracotomy is used to approach and treat anterior spinal lesions arising from various causes. Between 1990 and 1997, we treated 56 patients (40 men and 16 women) between 14 and 67 years old (mean 38.4). All had spinal lesions that were impossible or difficult to reach by a posterior approach. Thirty-one (55.3%) had suffered spinal damage, 8 (14.3%) had spinal deformities, 7 (12.5%) had metastatic tumors, 5 (8.9%) had herniated discs, 4 (7.1%) had Pott's disease and 1 (1.8%) had osteolysis at D6. Thoracotomy was left-sided in 35 cases (62.5%) and right-sided in 19 (33.9%). Video-assisted thoracoscopy was used twice (3.6%). The level of incision was based on the site of the lesion, and the pleural cavity was opened in all cases except one. The posterolateral pleuro-diaphragmatic fold was dissected and the diaphragm opened for retroperitoneal access in 37 cases (66.1%) of thoracolumbar disease. Orthopedic treatment consisted of autologous bone grafts in all cases and placement of a Kaneda splint in 32 cases (57.1%). One patient had to undergo surgery a second time due to inappropriate placement of the vertebral splint. Pneumothorax occurred in one patient after removal of pleural drains. The incision became infected in one patient, and one case of ileal paralysis was observed. Overall, morbidity was 7.1%. We conclude that thoracotomy offers a good alternative approach to spinal lesions. Results are good and morbidity low.

Clinical outcome after fusion of the thoracic or lumbar spine in the adult patient

This article highlights those disease processes for which fusion is used most frequently in the adult. Although the focus is on clinical outcome after fusion, the indications and natural history of the process itself are also briefly discussed to provide a comparative basis on which outcomes may be judged.

Thoracoscopic microsurgical excision of herniated thoracic discs

OBJECT

The authors began using thoracoscopy to treat pathological conditions of the spine in 1992. In this study they delineate their clinical experience in which this procedure was used to resect herniated thoracic discs.

METHODS

Fifty-five patients underwent thoracoscopy for the resection of herniated thoracic discs. Thirty-six patients presented with myelopathies and 19 with incapacitating thoracic radicular pain. Forty-three patients underwent a single-level, 11 a two-level, and one a three-level discectomy. The mean operative time for thoracoscopic microdiscectomy was 3 hours and 25 minutes (range 80-542 minutes) and the mean blood loss was 327 ml (range 124-1500 ml). Compared with thoracotomy, which was performed in 18 patients, thoracoscopy was associated with a mean of 1 hour less operative time and less than one-half of the blood loss, duration of chest tube drainage, usage of pain medication, and length of hospitalization. Compared with costotransversectomy, which was performed in 15 patients, thoracoscopy permitted more complete resection of calcified and midline thoracic discs because it provided a direct view of the entire anterior surface of the dura. Thoracotomy was associated with a significantly greater incidence of prolonged, disabling intercostal neuralgia compared with the mild transient episodes of intercostal neuralgia associated with thoracoscopy (50% compared with 16%). Thoracotomy also was associated with a significantly higher incidence of postoperative atelectasis and pulmonary dysfunction than thoracoscopy (33% compared with 7%). Clinical and neurological outcomes were excellent (mean follow-up period 15 months). Among the 36 myelopathic patients, 22 completely recovered neurologically; five improved functionally but had some residual myelopathic symptoms; and nine stabilized. Among the 19 patients with isolated thoracic radiculopathies, 15 recovered completely and four improved moderately; no patient had worsened radicular pain.

CONCLUSIONS

Thoracoscopic microdiscectomy is a reliable surgical technique that can be performed safely with excellent clinical and neurological results.

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.

Endoscopic microscopic transpedicular thoracic discectomy. Technical note

In an effort to make thoracic discectomy simple and less invasive while using direct visualization, a 70 degrees-angled lens endoscope has been adopted to visualize the ventral aspect of the spinal cord dura mater during microsurgical thoracic discectomy via a transpedicular approach. The patient is positioned in a 60 degrees forwardly inclined lateral position with the side of the lesion facing upward. After radiographic corroboration of the correct level, a transpedicular approach is made using a 1.5-cm-diameter tubular retractor through a 2-cm-long paramedian transverse skin incision. With the aid of an operating microscope, the ipsilateral facet joint, including the upper portion of the pedicle, is removed using a high-speed drill, thus exposing the neural foramen, intervertebral disc, and upper portion of the pedicle leading to the vertebral bodies. When the herniated disc and bone spur have been removed laterally in relation to the spinal cord, creating a cavity under the operating microscope, a 4-mm-diameter rigid endoscope with a 70 degrees-angled lens is mounted to an endoscope holder so that the ventral aspect of the spinal cord dura mater can be visualized directly. With the aid of direct endoscopic visualization, the disc and bone spur, which compress the spinal cord anteriorly, are pushed away toward a cavity created at the intervertebral space and are removed using a downward-biting long-armed curette. Patients with myelopathy are kept overnight in the hospital; however, those with radiculopathy are discharged home on the same day as their operation. The surgical technique and two illustrative cases are reported.

Surgical treatment of thoracic disc herniation: a reappraisal of Larson's lateral extracavitary approach

Twenty patients with thoracic disc herniations underwent removal of the transverse process, articular facet, pedicle, and rib--a procedure described by Larson as the lateral extracavitary approach. Eleven patients presented with myelopathy: five mild, nine moderate, and four severe. Fifteen patients showed significant neurologic improvement after the operation and five patients none. Postoperative follow-up ranged from 1 to 8 years. The pros and cons of each of the surgical approaches to this type of lesion are considered with reference to the published data.

The transfacet pedicle-sparing approach for thoracic disc removal: cadaveric morphometric analysis and preliminary clinical experience

A number of operative techniques have been described for the treatment of herniated thoracic discs. The transfacet pedicle-sparing approach allows for complete disc removal with limited spinal column disruption and soft-tissue dissection. Fifteen cadaveric spinal columns were used for evaluation of exposure, development of thoracic microdiscectomy instrumentation, and establishment of morphometric measurements. This approach was used to remove eight thoracic discs in six patients. Levels of herniation ranged from T-7 through T-11. Preoperatively, all patients had moderate to severe axial pain, and three (50%) of the six had radicular pain. Myelopathy was present in four (67%) of the six patients. Through a 4-cm opening, the ipsilateral paraspinal muscles were reflected, and a partial facetectomy was performed. The disc was then removed using specially designed microscopic instrumentation. Postoperatively, the radiculopathy resolved in all patients. Axial pain and myelopathy were completely resolved or significantly improved in all patients. The minimal amount of bone resection and muscle dissection involved in the operation allows for: 1) decreased operative time and blood loss; 2) diminished perioperative pain; 3) shorter hospitalization time and faster return to premorbid activity; 4) avoidance of closed chest tube drainage; and 5) preservation of the integrity of the facet-pedicle complex, with potential for improvement in outcome related to axial pain. This technique appears best suited for the removal of all centrolateral discs, although it has been used successfully for treating a disc occupying nearly the entire ventral canal. The initial experience suggests that this approach may be used to safely remove appropriately selected thoracic disc herniations with good results.

Video-assisted endoscopic spinal surgery: thoracoscopic discectomy

The use of new endoscopic techniques to conduct a thoracic discectomy is presented. The development of these endoscopic techniques through live porcine and cadaver models are outlined. It is concluded that the use of multiple ports for the endoscopic approach to the thoracic spine provides an exposure to the anterior and lateral spinal theca that is equal to the exposure afforded by the more extensive thoracotomy. Current techniques are being developed for transperitoneal and retroperitoneal endoscopic lumbar spine surgery.

Posterolateral approach to intradural extramedullary thoracic tumors

Six ventrally located intradural thoracic tumors were successfully resected through the posterolateral approach. This approach allows direct visualization of the ventral and dorsal boundaries of the tumor with minimal manipulation of the spinal cord. Compared to the traditional laminectomy, the operative time is increased but visualization of the tumor and spinal cord is markedly improved. Compared to the transthoracic approach, the posterolateral approach has fewer potential complications and eliminates the necessity of vertebrectomy. Neurological improvement occurred in all six patients. It is believed that this approach offers significant advantages for the treatment of ventrally located intradural thoracic tumors, and should be considered an alternative to the transthoracic 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.

Thoracic approaches to anterior spinal operations: anterior thoracic approaches

We performed a retrospective review of 36 patients aged 23 to 71 years (mean age, 52 years) who underwent 46 operations through a thoracic or thoracolumbar approach for orthopedic or neurosurgical procedures at Emory University Affiliated Hospitals. Pathologic indications for operation were metastatic disc disease in 10, herniated nucleus pulposus in 11, osteomyelitis in 6, vertebral fracture in 2, spinal deformities in 4, spinal abscess in 1, Pott's disease in 1, and liposarcoma in 1. Major indications for operation were infection and progressive paraparesis or paresthesias. Surgical approach consisted of a posterior lateral thoracotomy in 23, thoracotomy with retroperitoneal exposure in 6, thoracoabdominal exposure in 4, and cervical/upper sternotomy in 3. Diaphragmatic mobilization was required in 12. Surgical approach is dictated by the level of the lesion and its length. Lesions of T1 to T6 are approached through an upper sternotomy or right thoracotomy; lesions of T6 to L3, through a left thoracotomy with or without diaphragmatic mobilization. Specific techniques of segmental vessel division, diaphragmatic mobilization, and evaluation of artery of Adamkiewicz are emphasized. Rib grafts are harvested as needed. The thoracic surgeon can greatly enhance preoperative assessment, operative exposure and closure, and postoperative care for patients undergoing thoracotomy for spinal conditions.

Thoracic disc herniation. Analysis of 14 cases and review of the literature

Fourteen cases of thoracic intervertebral disc prolapse are reported and analysed. Eleven were women, 3 men, and the peak incidence was in the 5th decade. No trauma was reported in our cases. The T8/9 interspace was the most frequently involved. A sensory level was noticed in 6 cases and in four a clear cut sensory level at T10 was observed. Results of surgical treatment show that using microsurgical techniques costotransversectomy and its modifications are equally effective; laminectomy is contraindicated.

Anterolateral transthoracic transvertebral resection of an intramedullary spinal arteriovenous malformation. Case report

The case is reported of a 16-year-old girl with an anterior thoracic spinal cord arteriovenous malformation (AVM) who presented with subarachnoid hemorrhage and sudden change in lower-extremity strength. Spinal angiography revealed a Type II (glomus) intramedullary AVM at the T7-8 level fed by multiple branches of the anterior spinal artery. The AVM was successfully resected using an anterolateral transthoracic approach. The details of this approach and its use for surgery of anterior thoracic spine lesions are described.

Surgical approaches to thoracic disc herniations

Early diagnosis of thoracic disc herniations has become more common with the advent of spinal magnetic resonance imaging (MRI). This early diagnosis combined with choosing the optimal surgical approach, to ensure adequate decompression without excessive cord and root manipulation, will achieve the optimum results. It is now clear that more lateral and anterior approaches to the thoracic spine are required to achieve this goal. We report our experience in the operative management of 21 patients with thoracic disc herniation using three different surgical approaches: transpedicular-transfacetal, posterolateral-extrapleural (costotransversectomy) and transthoracic-transpleural. The clinical and radiologic findings and results in all of our cases are reviewed as are the technique of and indication for each of the three surgical approaches.

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.

Spinal cord compression due to thoracic disc herniation: results of microsurgical posterolateral costotransversectomy

Fifteen consecutive patients with thoracic disc herniation treated by posterolateral microsurgical costotransversectomy are described. With appropriate modifications to the standard technique, costotransversectomy was found to be a suitable approach even for calcified central discs, and discs which had eroded intradurally. All patients had evidence of spinal cord compression preoperatively with varying degrees of leg weakness. The results of surgery are discussed. Ten patients who were disabled but ambulant showed marked improvement in symptoms and signs. Of the remaining five, all of whom were severely disabled and nonambulant preoperatively, four demonstrated significant improvement. Most patients mobilised rapidly, 13 being able to walk unaided within 24 hours. One patient developed an intrathoracic meningocoele postoperatively, which resolved after multiple percutaneous aspirations. Otherwise there were no serious pulmonary complications. We believe that costotransversectomy is the approach of choice for central as well as centrolateral and lateral thoracic disc herniations.

Thoracic intervertebral disc protrusion: experience of 67 cases and review of the literature

Sixty-seven cases of thoracic intervertebral disc protrusion are reported with an analysis of clinical and radiological findings. The findings include the fact that male: female ratio is approximately equal, peak incidence is in the 3rd to 5th decade with another peak at age 30-40 in men. This latter peak appears to be associated with trauma which is otherwise uncommon. Results of surgical treatment indicate that the transthoracic and costotransversectomy routes are almost equally effective; laminectomy is not advised.

Multiple thoracic disc herniations. Case report

A patient with herniated thoracic discs in tandem is reported. The previous literature is reviewed. Difficulties with the preoperative diagnosis and the surgical approach to these lesions are discussed.

Bilateral posterolateral approach to the thoracolumbar spine through transversoarthropediculectomy with corporectomy

Surgery of the dorsolumbar spine is currently benefiting from diverse approaches and the advent of computed tomography. This report describes a bilateral posterolateral approach with transversoarthropediculectomy and corporectomy. The advantages and disadvantages of this approach and its indications are discussed.

The ominous discoloration of the spinal cord due to thoracic disk protrusions: a historical note

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