Thoracic disc herniation:Thoracic disc herniation:Postero-lateral approachPostero-lateral approach

Antonino Raco MDProfessor and Chairman  of Neurosurgery

Department of Neurosciences, Mental Health and Sense Organs (NESMOS),Sapienza Università di Roma

Azienda Ospedaliera Sant’Andrea, Rome

Thoracic disk herniation

• Minority of disk hernations• 1 symptomatic patients per million per year• The majority are located below T8• 70-90% are centrally located• 20-60% are calcified• 5-6% are intradural

Clinical presentation

• Axial or radicular pain in more then 60%• Motor signs (weakness, spasticity or hyperreflexia

due to mielopathy) in 50%• Bladder disfunction in 20-30 %• Sensory changes (radicular or medullary) in more

then 60 %

• J Neurosurg. 1998 Apr;88(4):623-33. Experience in the surgical management of 82 symptomatic herniated thoracic discs and review of the literature. Stillerman CB, Chen TC, Couldwell WT, Zhang W, Weiss MH

• Neurol Med Chir (Tokyo). 2011;51(1):67-71. Thoracic disk herniation manifesting as sciatica-like pain two case reports.Cho HL, Lee SH, Kim JS.

Clinical presentation

• Approximately 4% of TDHs present with an acute myelopathy. They are often situated between T9-10 and T11-12, large or giant, and even calcified

• A precipitating event or trauma is rarely present, dorsalgia frequently precedes profound myelopathy and may help to make an early diagnosis. Remarkable recovery is possible even with profound neurological deficit, a delay of several days, in the elderly, and in the presence of myelomalacia, provided the spinal cord is adequately decompressed and intraoperative hypotension is strictly avoided

• “every single patient should undergo surgical treatment”

• J Neurosurg Spine. 2011 Apr;14(4):520-8. Epub 2011 Feb 11. Thoracic disc herniation and acute myelopathy: clinical presentation, neuroimaging findings, surgical considerations, and outcome. Cornips EM, Janssen ML, Beuls EA

Indications to surgery

• The natural history of thoracic disk herniation is not completely understood

• Mielopathy is an absolute indication for surgery

• While a conservative attempt is indicated for radicular symptoms (77% of patients returned to work symptom free without surgical intervention)

Spine (Phila Pa 1976). 1992 Jun;17(6 Suppl):S97-102. The natural history of thoracic disc herniation.Brown CW, Deffer PA Jr, Akmakjian J, Donaldson DH, Brugman JL.

Surgical approach: anterior or postero-lateral ?

• Level of herniation• Mediolateral localisation of herniation• Calcification• Intradural location• Comorbidity• Experience of surgeon

Postero-lateral approaches: anatomical remarks

Posterolateral approaches: anatomical remarks

Extended Fessler’s approach for cervico-thoracic junction

Extended Fessler’s approach for cervico-thoracic junction

Postero-lateral approaches: anatomical remarks

adamkiewicz artery

Adamkiewicz artery

Postero-lateral approaches

• They do not allow true ventral view of the spinal canal• They offers gradually increasing exposures toward the

midline of the canal• They are indicated for more laterally located disks, for soft

disk without evidence of calcifications and for extradural herniation

Is there still space for Laminectomy ?

Is there still space for Laminectomy ?

Because of the associated high rates of morbidity and mortality, standard laminectomy alone is not an acceptable approach for the treatment of thoracic disc disease.

Neurological deterioration is rarely associated with the alternative surgical approaches, and its incidence is comparable among the approaches

No single complication appears to be definitively associated with any single approach

Transpedicular approach

• A unilateral exposure can be performed to minimize trauma to controlateral paravertebral musculature• Vertical midline or curvilinear (convexity toward midline) skin incision

•Identification of pedicle projection (2 mm beneath the edge of the inferior facet of superior vertebra)

Transpedicular approach

• Laminotomy to enter the spinal canal• Drilling of medial facet and visualisation of nerve root• Drilling of the interior of pedicle, preserving the medial and superior part, which will be removed once reached the depth of the disk space/vertebral body

Transpedicular approach

•20 consecutive patients

•No patient experienced worsening of neurological status

•The TP approach is most applicable to lateral calcified or median soft herniation

Transfacet approach

• The approach is similar to transpedicular but avoids the resection of pedicle

• Ideal for lateral and intraforaminal disk herniation

Transfacet approach

• Medial facet can be only partially removed and approach can be completed with laminotomy

Transfacet approach

• J Neurosurg Spine. 2011 Jul;15(1):76-81. Epub 2011 Apr 8. Surgical management of multiple thoracic disc herniations via a transfacet approach: a report of 15 cases. Arnold PM, Johnson PL, Anderson KK.

• “Only patients with lateral disc herniations were considered for the modified transfacet approach”

• “Complications were minimal…”

Transfacet approach

“All patients underwent a transfacet pedicle-sparing decompression and segmental instrumentation with interbody fusion”

“The mean estimated blood loss was 870 ml with no dural tears." “Five patients developed postoperative wound infections or seromas

…One patient had a misplaced screw and suboptimally positioned interbody graft requiring revision. One transient neurological deterioration occurred postoperatively associated with an inferior segment fracture 20 days after surgery”

Transcostovertebral approach

•Less invasive then costotrasversectomy beacuse only the posterior cortex of the rib head is removed

•The exposure is extended to transverse process, which is removed to reveal the rib head

•Drilling the lateral part of the facet joint and the upper one half of pedicle to visualize the spinal cord and nerve root

•Further drilling through the posterior part of the rib head untill the annulus is identified

•The key point is “ staying within the costovertebral joint…”

•If nerve root is mantained, the authors noted frequent postop radiculopathy…

J Neurosurg. 2001 Jan;94(1 Suppl):38-44. Transcostovertebral approach for thoracic disc herniations. Dinh DH, Tompkins J, Clark SB.

Transcostovertebral approach

“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”

J Neurosurg. 2001 Jan;94(1 Suppl):38-44. Transcostovertebral approach for thoracic disc herniations. Dinh DH, Tompkins J, Clark SB

Costotransversectomy

•The skin is medially and muscles are laterally reflected to allow visualisation of the ribs and transverse process, wich are dissected and removed

•Visualisation of pedicle, neurovascular bundle, superior rib and pleura

•Pedicle should be drilled just inferior to the affected disk space, to identify dural sac and nerve root without causing any damage

•Closure requires inspection of the dura and eventually the placement of a chest tube

Lateral extracavitary approach

Larson et al 1976, modification of Capener’s technique 1954

It is most aggressive posterolateral approach, and it offers the greatest visualisation of the anterior canal via a posterior incision

Compared to costotransversectomy, a larger lateral resection of the inferior rib is performed

Lateral extracavitary approach

•20 patients•11 with mielopathy•15 showed significant neurologic improvement after the operation and five patients none.• No significant approach related morbidity

Surgical Neurology 1996

Postero-lateral approaches: potential complications

• Injury to neurovascular bundles.• Injury to pleura.• Lung contusion.• Injury to great vessels lying anterior to the

vertebral body.• Dural tears.• Postoperative atelectasis of lung.• Infection.

Intradural herniation

• Br J Neurosurg. 2007 Feb;21(1):32-4. Thoracic intradural disc herniation. Almond LM, Hamid NA, Wasserberg J.

“Intradural thoracic disc herniation at the T11-T12 level, the intradural nature of which was not diagnosed on preoperative MRI…”

Intradural herniation

• “posterolateral transpedicular approach with partial removal of the facet and pedicle of the vertebral body inferior to TDH”

• “when there is a combination of BSS and a large radiological calcified herniation we recommend opening the dura mater”

Transdural approach

“After the laminectomy, at the involved level, the dorsal dura was opened with a longitudinal paramedian incision. The cerebrospinal fluid was drained to gain more operating space. After sectioning of the dentate ligaments, gentle retraction was applied to the spinal cord. Between the rootlets above and below, the ventral dural bulging was clearly observed. A small paramedian dural incision was made over the disc space and the protruded disc fragment was removed.”

Difficulty in suturing ventral duraNeurological symptoms were improved, and no surgery-related complication

was encountered.Recommended only for soft disks!

Miniopen Retropleural approach

Results: posterior vs anterior

Surg Neurol. 1998 Jun;49(6):599-606; discussion 606-8. Thoracic disc herniations: transthoracic, lateral, or posterolateral approach? A review. Mulier S, Debois V.

• 331 patients• Partial or total neurological recovery was found in 93% after a

transthoracic procedure versus 87% after a posterolateral technique and 80% after a lateral approach (P < 0.05). A trend toward superior results after a transthoracic technique was also noted in subgroups of patients with radiculopathy, patients with intradural disc herniations, and patients with multiple lesions

• Pulmonary complications occurred in 7% of transthoracic techniques versus 5% in lateral and 0% in posterolateral techniques (p < 0.025).

• The transthoracic approach is recommended for all thoracic disc herniations below the T4 level except for patients with serious pulmonary compromise

Results: posterior vs anterior

• This review has evaluated in 1998 the morbidities and mortalities reported over the last 60 years for the surgical treatment of thoracic disk disease

Results: posterior vs anterior

• Laminectomy does not provide adequate access for the safe removal of these lesions.

• The other postero-lateral approaches should be choosed according to the location of herniated disk (medial or lateral), the general health of the patient and the surgeon’s experience

Results: posterior vs anterior

Results: posterior vs anterior

“Posterior approaches remain a viable alternative for a large proportion of patients with symptomatic thoracic disc herniations.”

“ it appears not appropriate to perform primary fusion procedures in patients with thoracic disc herniations”

Minimally invasive surgery

• The authors describe a minimally invasive lateral extracavitary tubular approach for discectomy and fusion

• In 13 patients (5 men, 8 women; mean age 51.8 years) with myelopathy and 15 noncalcified TDHs, the authors achieved a far-lateral trajectory by dilating percutaneously to a 20-mm working portal docked at the transverse process-facet junction, which then provided a corridor for a near-total discectomy, bilateral laminotomies, and interbody arthrodesis requiring minimal cord retraction.

Minimally invasive surgery

MIS

• Orthop Clin North Am. 2007 Jul;38(3):351-61. Techniques for the operative management of thoracic disc herniation: minimally invasive thoracic microdiscectomy. Sheikh H, Samartzis D, Perez-Cruet MJ

• Tubular retraction and microscope• Lateral herniation or central soft herniation• Not for calcified central herniation

• Minim Invasive Neurosurg. 2011 Aug;54(4):167-71. Epub 2011 Sep 15.Minimally invasive retropleural approach for central thoracic disc herniation. Kasliwal MK, Deutsch H.

Case #1

R.P. 45 years womanDorsal Mielopathy

Case #1

Transfacet pedicle sparing approach

Case #1

Case #2

Case #2

Case #2: Positioning and Monitoring

Case #2: Surgery

Case #2: Surgery

Case #2

Case #3

52 years-old womanSevere radicular pain for 6 months, not responsive to medical therapy

Case #3

Transpedicular approach

Conclusions

• Posterolateral approaches may be used for lateral or median soft herniated disk

• The more median is the herniation, the more lateral has to be the approach

• Transfacet and transpedicular approaches are in general sufficient to treat the majority of cases

• Transthoracic approach can be reserved for large, median and calcified herniation

Conclusions

• Minimally invasive tubular approaches to facet and pedicle represents probably the surgical evolution and every surgeons should be familiar with them

• Results for MIS need to be validated