|Year : 2020 | Volume
| Issue : 1 | Page : 97-101
Thoracic discectomy by tubular retractor: Clinical case
Amit C Jhala, Shivam K Kiri, Sharvil Gajjar
Department of Spine Surgery, Chirayu Hospital, Ahmedabad, Gujarat, India
|Date of Submission||30-Apr-2019|
|Date of Decision||24-Oct-2019|
|Date of Acceptance||02-Dec-2019|
|Date of Web Publication||05-Feb-2020|
Dr. Amit C Jhala
Dr. Amit Chandrakant Jhala, Department of Spine Surgery, Chirayu Hospital, Ahmedabad, Gujarat.
Source of Support: None, Conflict of Interest: None
Thoracic disc herniation is a rare condition in spine surgery. Surgical treatment is indicated for myelopathy, intractable radiculopathy, or persistent axial back pain. Various open approaches (anterior, anterolateral, posterior, or posterolateral), for thoracic discectomy have been described. These approaches have morbidity and a lot of collateral muscle damage. Minimally invasive approaches have been developed to decrease the morbidity of the open approaches. Here we describe the case of central thoracic disc herniation, which was operated by a minimally invasive transforaminal approach with technical details.
Keywords: Minimally invasive, thoracic disc, tubular retractor
|How to cite this article:|
Jhala AC, Kiri SK, Gajjar S. Thoracic discectomy by tubular retractor: Clinical case. Indian Spine J 2020;3:97-101
| Introduction|| |
Thoracic disc herniation (TDH) is one of the rare conditions in spine surgery. The incidence ranges from 1 in 1,000 to 1 in 1,000,000 in the general population, and thoracic discectomy constitutes only 0.15%–4% of all discectomies. Surgical treatment for TDH is indicated for severe or progressive myelopathy, persistent axial back pain, or intractable radiculopathy. Depending on the type of disc prolapse, central or paracentral, many different approaches, either anterior or posterior, have been described. Here we describe a case of central TDH, which was removed by a minimally invasive approach with the help of a tubular retractor.
| Case Report|| |
A 47-year-old woman presented with complaints of back pain, difficulty in maintaining balance, and numbness in both lower limbs since the last 3 months. There was no involvement of bladder or bowel. The patient had a history of diabetes and hypertension. On examination, the patient had generalized spinal and paraspinal tenderness. There was no step or gibbus. The result of bilateral straight leg raise test was found to be negative. Neurologically, there was a weakness of left lower limb with hip flexion, knee flexion, and knee extension power grade 3/5 according to MRC (Medical Research Council) grading. The muscle power of all muscle groups of the right lower limb was 5/5. The sensory examination was normal. Knee jerks were exaggerated, ankle jerks were absent, and bilateral Babinski sign was positive. The patient’s bowel and bladder were uninvolved. Plain X-ray showed decreased disc space at D11 and D12 [Figure 1]. Magnetic resonance imaging (MRI) showed central disc herniation between D11 and D12 vertebrae [Figure 2].
|Figure 1: X-ray D/L spine (A) AP view and (B) lateral view showing decreased disc space between D11 and D12 vertebrae|
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|Figure 2: (A) T2-weighted sagittal MRI showing D11-D12 superiorly migrated disc herniation. (B) T2-weighted axial MRI showing D11-D12 central disc herniation|
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| Surgical Technique|| |
The patient was kept in a prone decubitus position under general anesthesia with abdomen kept free to reduce pressure. Percutaneous screws were inserted on the right side and K wires for the percutaneous screws were inserted on the left side in D11 and D12 pedicle under fluoroscopic guidance. The docking point for the tubular retractor was marked by tilting the fluoroscope to 15° on the left side and end-on view of the left D11-D12 foramen was obtained. The disc space, facet complex, pedicle, and pars were aligned and one could see the D11-D12 foramen. The docking site was at the inferior transverse process (D12), facet, and pedicle complex junction. Then series of sequentially larger tubular dilators were inserted. Finger dissection was used to palpate the transverse process–facet junction. Expandable tubular retractor was used for docking. Docking was one-third on the facet and two-third outside the facet in anteroposterior (AP) view and parallel to D11 and D12 disc space in lateral view. Visualization of space between the costotransverse joint and facet joint was carried out. The microscope was used for a dissection through the tube. Facet joint, part of the lamina, and inferior transverse process were removed. The working tube was inserted deeper and medially directed toward the disc and foramen. The inferior pedicle was identified and disc space was entered with its guide. Thorough discectomy was carried out. Dura could be visualized posteriorly, laterally, and anteriorly on the left side. Endplate preparation was carried out with curettes and shavers. Bone graft was inserted in the disc-space. The screws on the left-side D11 and D12 pedicles were then inserted over the K wire. Compression was carried out and closure was carried out in layers [Figure 3].
|Figure 3: (A) Oblique view of thoracic spine showing the foramen. (B) Incision between the two ribs on the lateral border of the vertebra. (C) Peroperative picture showing expandable tubular retractor in position. (D) Close-up view through expandable tubular retractor|
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| Postoperative Course|| |
The patient had decreased power by grade 1. Postoperative steroids were given with physical therapy. At 3-month follow-up, patient showed motor power recovery with persistent residual sensory paresthesias. [Figure 4] shows the postoperative X-ray and [Figure 5] shows the immediate postoperative MRI. Postoperative MRI shows good decompression compared to the preoperative compression.
|Figure 4: Immediate postoperative X-ray: (A) AP view and (B) lateral view|
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|Figure 5: (A) Postoperative T2-weighted sagittal MRI. (B) Postoperative T2-weighted axial MRI showing decompression. (C) Postoperative CT scan axial view|
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| Discussion|| |
Surgery for TDH is rare. There are many approaches for TDH. Laminectomy and discectomy for TDH are easiest of the procedures but the outcomes are poor with high chances of postoperative deterioration because of spinal cord manipulation, which may be required for performing anterior discectomy. The first authors to report clinical data for this treatment were Mixter and Barr in 1934. Their results and the results of other series reporting the use of a standard laminectomy approach were disappointing, yielding major morbidity rates of 18%–75% and mortality rates up to 50%., As a result, many alternative surgical approaches, including the transpedicular, transfacet pedicle sparing, costotransversectomy, lateral extracavitary, and transthoracic approaches, were developed. Open transthoracic approaches have a high rate of postoperative morbidity. The thoracoscopic approach was developed to reduce the morbidity but it has a high learning curve. Menard et al. first developed open costotransversectomy approach in 1894. Hulme used this approach for thoracic discectomy in 1960. It allows access to both the anterior and lateral parts of the vertebra with safe circumferential decompression and no morbidity of the transthoracic approach and allows posterior stabilization if required. Similarly, the lateral extracavitary approach gives a wider anterior and posterior exposure, which was developed by Larson et al. in 1976. Anterior and anterolateral approaches are better for central TDHs as they have the least manipulation of the thoracic cord. However, both these approaches also are morbid with a lot of collateral tissue damages. Posterolateral approaches such as transpedicular or transfacetal can decrease the spinal cord manipulation and give good access for posterolateral disc prolapse. The bilateral transpedicular approach or transfacetal approach can also be used for central disc herniation. Although these approaches enable the safe decompression of disc fragments, they necessitate a fairly large surgical incision, soft-tissue dissection, and resection of vertebral osseous structures, which may result in significant operative blood loss, postoperative pain, and prolongation of the postoperative hospital stay. Minimally invasive approaches have developed with the advent of the tubular retractors, which decrease the collateral tissue damage and clinically decrease the bleeding, postoperative pain, and morbidity with early postoperative rehabilitation. Minimally invasive posterior approaches for thoracic discectomy using tubular retractors through foraminal or extracavitary approaches have been reported., However, this approach requires removal of the rib head, resulting in morbidity. Regev et al. developed minimally invasive transforaminal thoracic discectomy using tubular retractor. This approach does not require removal of the rib head and gives adequate access to the anterior and posterior aspects of the dura and can be used for central TDH. We have used this approach in our case for thoracic discectomy. We had deterioration in neurology of patient by grade 1 power immediately postoperatively, which could be due to some cord manipulation and edema. But at 3 months postoperatively, patient had recovered from the neurological deterioration in motor power although she had some residual sensory paresthesias. This procedure requires technical experience with use of tubular retractor. We did instrumentation in our case as it was at D11-D12 region, which is not inherently stable region, and we had to completely remove facet joints from one side. The outcomes of the thoracic discectomy by minimally invasive tubular approach have been reported with excellent clinical outcomes in different series.,,,
| Conclusion|| |
Adequate decompression by minimally invasive tubular approach of TDH in this case could be achieved safely with less collateral muscle damage, less morbidity, and less postoperative pain.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]