Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12612000780853
Ethics application status
Not yet submitted
Date submitted
20/07/2012
Date registered
24/07/2012
Date last updated
24/07/2012
Type of registration
Prospectively registered

Titles & IDs
Public title
A trial comparing minimally invasive spinal surgery with open spinal surgery to treat narrowing of the spinal canal
Scientific title
Randomised Controlled Non-inferiority Trial Of Minimally Invasive Versus Standard Open Decompression For Degenerative Lumbar Canal Stenosis, comparing functional outcomes, pain scores, and complications in both procedures.
Secondary ID [1] 280885 0
Nil
Universal Trial Number (UTN)
U1111-1132-8416
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Degenerative lumbar canal stenosis 286955 0
Condition category
Condition code
Surgery 287293 287293 0 0
Surgical techniques
Neurological 287298 287298 0 0
Other neurological disorders
Musculoskeletal 287315 287315 0 0
Other muscular and skeletal disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Minimally invasive decompressive laminectomy - the hypertrophied ligamentum flavum and facets are undercut with surgical access through a small working tube, as opposed to a long midline incision. In this manner the spinal canal and neural elements are decompressed, whilst preserving the spinal extensor muscles, and the spinous processes. The procedure takes approximately 90-120 minutes of operating time.
Intervention code [1] 285317 0
Treatment: Surgery
Comparator / control treatment
Standard treatment - open decompressive laminectomy. Through a midline skin incision, the lamina and spinous processes of the vertebrae are removed, and hypertrophied ligamentum flavum removed. This allows decompression of the spinal canal and neural elements. An open decompressive laminectomy takes approximately 90-120 minutes of operating time.

Open decompressive laminectomy has been shown to be superior to non-surgical treatment in previous randomised trials, but has not been directly compared to the newer minimally invasive techniques.
Control group
Active

Outcomes
Primary outcome [1] 287568 0
Oswestry Disability Index at 6 months post operatively
Timepoint [1] 287568 0
6 months post op
Secondary outcome [1] 298424 0
Post operative pain - Visual Analogue Score
Timepoint [1] 298424 0
One day post operatively
Secondary outcome [2] 298425 0
Operative complications
1. Intraoperative dural tear - as observed at theatre
2. Post operative CSF leak - if clinically observed in post operative
period.
3. Post operative infection - diagnosied clinically, and if necessary with post operative blood tests and/or MRI imaging
4. Blood transfusion requirements - retrieved from the medical record of the inpatient episode
5. Second surgical procedure at the operative level - retrieved from the medical record of the inpatient episode
6. Post operative spondylolisthesis - diagnosed on post operative MRI and X-ray
Timepoint [2] 298425 0
At time of intervention

Long term spondylolisthetic complications will be detected at follow up imaging at 6 months
Secondary outcome [3] 298426 0
EuroQuol EQ-5D Quality of Life outcome
Timepoint [3] 298426 0
4 weeks post op
6 months, 12 months, and 24 months post op
Secondary outcome [4] 298430 0
Post operative MRI and X-ray at 6 months to assess extent of canal decompression, and exclude late onset of post operative spondylolisthesis or instability.
Timepoint [4] 298430 0
6 months post op
Secondary outcome [5] 298431 0
Oswestry Disability Index at 12 months and 24 months post op
Timepoint [5] 298431 0
12 months and 24 months post op

Eligibility
Key inclusion criteria
Patients with symptomatic degenerative lumbar canal stenosis with neurogenic claudication and/or lumbar radiculopathy
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Cauda equina syndrome
Requirement for instrumentation
Prevous lumbar spine surgery at the affected level(s)
Dependent in ADLs (Karnofsky Score <60)
Psychiatric illness
Other significant comorbidities that may affect pain scores

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Randomisation by off site techniques
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation - "coin toss"
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Phase 3
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
1/08/2012
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
30
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 285676 0
Self funded/Unfunded
Name [1] 285676 0
Jason McMillen/Martin Wood
Country [1] 285676 0
Australia
Primary sponsor type
Individual
Name
Jason McMillen
Address
Mater Misericordiae Private Hospital
301 Vulture Street
South Brisbane Queensland 4101
Country
Australia
Secondary sponsor category [1] 284505 0
None
Name [1] 284505 0
Address [1] 284505 0
Country [1] 284505 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 287663 0
Mater Medical Research Institute Human Research Ethics Committee and Governance
Ethics committee address [1] 287663 0
MMRI HREC
Level 3, Quarters Building
Mater Hospital
Raymond Terrace
South Brisbane Qld 4101
Ethics committee country [1] 287663 0
Australia
Date submitted for ethics approval [1] 287663 0
22/06/2012
Approval date [1] 287663 0
Ethics approval number [1] 287663 0

Summary
Brief summary
Surgical decompression of the lumbar canal in patients with significant symptoms of claudication or radicular pain and a radiological diagnosis of canal stenosis is both efficacious and well tolerated, with sustained long term benefits. Historically, lumbar canal stenosis was treated with complete laminectomy but recognition that the pathology is largely at the level of the disc and interlaminar space has led to less destructive approaches such as interlaminar decompression or laminotomy. Despite this, all published series report some morbidity and complications from surgery in what is typically an elderly population, such as dural tear, infection, persistent back pain and the need for blood transfusion or further surgical intervention. One concern is that of post-operative spondylolisthesis, which is thought to occur from disruption of the spinous processes and interspinous ligament, observed in up to 30% in some series.

Minimally invasive techniques for decompression of the lumbar canal using a micro-endoscopic approach have been described and are growing in popularity. Instead of a midline posterior approach to the spinal canal, where the muscles are dissected bilaterally and the posterior spinal structures removed, a minimally invasive technique uses a unilateral, paramedian approach where the muscles are preserved and surgery is carried out through an 18mm diameter working tube. The surgical field is illuminated and magnified under the operating microscope and custom designed bayoneted instruments are employed to avoid obscuring vision. The spinal canal is decompressed in the same way as one would using an open approach but the posterior spinal structures are largely preserved, which offers a biomechanical advantage with the potential to reduce late spondylolisthesis. The less destructive approach should also reduce early post-operative back pain, promote more rapid mobilisation, and consequently reduce the number of inpatient hospital days.

There is a growing body of evidence supporting the efficacy of this technique for treating patients with lumbar canal stenosis though there are concerns over the adequacy of decompression through a small operating tube and the learning curve associated with the adoption of this less invasive but potentially more restricted technique. Thus far, a number of observational studies have implied early advantages to patients offered minimally invasive over open lumbar canal decompression, there has yet to be a properly conducted and appropriately powered randomised controlled trial to confirm that the techniques are similarly effective in terms of medium to long-term functional outcome. A phase III non-inferiority trial design, i.e., to show that minimally invasive lumbar canal decompression is not inferior to standard open lumbar decompression, is considered to be the most stringent and statistically appropriate trial design to answer this important question.

Trial participants will be recruited from patients undergoing elective open or minimally invasive decompressive lumbar laminectomy for degenerative lumbar canal stenosis at the Mater Misericordiae Private Hospital. After obtaining consent for the patients’ participation in the trial, they will undergo pre-operative clinical and radiological assessment by their consultant surgeon, including MRI and X-ray lumbar spine, in the usual way. Baseline questionnaires will be obtained pre-operatively. After randomisation to either surgical arm, open or minimally invasive lumbar decompression surgery will proceed in the usual way. There will be no changes to the usual surgical management of the patient resulting from the trial.

Post operative management will proceed in the usual way, with no changes to normal post operative surgical management. Patients will complete outcome questionnaires prior to discharge. Patients will be assessed for discharge by a physiotherapist and their surgeon, and discharged at a clinically appropriate time in the usual way. Patients will be followed up at their routine appointment with the consultant surgeon. Outcome questionnaires will be completed at periods up to 24 months post operatively, and a follow up X-ray and MRI lumbar spine will be obtained. Data obtained will allow comparison of the outcomes of the two surgical procedures, including patient outcome measures, morbidity and adverse events, and radiological outcomes including extent of decompression and development of late spondylolisthesis.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 34465 0
Address 34465 0
Country 34465 0
Phone 34465 0
Fax 34465 0
Email 34465 0
Contact person for public queries
Name 17712 0
Dr Martin Wood
Address 17712 0
Suite 5.02, Fifth Floor
Mater Private Clinic
550 Vulture Street
South Brisbane Qld 4101
Country 17712 0
Australia
Phone 17712 0
+61 7 3163 2830
Fax 17712 0
+61 7 3163 2829
Email 17712 0
[email protected]
Contact person for scientific queries
Name 8640 0
Dr Martin Wood
Address 8640 0
Suite 5.02, Fifth Floor
Mater Private Clinic
550 Vulture Street
South Brisbane Qld 4101
Country 8640 0
Australia
Phone 8640 0
+61 7 3163 2830
Fax 8640 0
+61 7 3163 2829
Email 8640 0
[email protected]

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

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