Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT04611464 |
Other study ID # |
19-006 |
Secondary ID |
|
Status |
Completed |
Phase |
|
First received |
|
Last updated |
|
Start date |
July 11, 2019 |
Est. completion date |
June 1, 2020 |
Study information
Verified date |
October 2020 |
Source |
Dallas VA Medical Center |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
This single-group cross-sectional cohort study will enroll approximately 25 patients at the
North Texas VA Health Care System (VANTHCS) who have previously received off-label
prescriptions of misoprostol for lumbar spinal stenosis for any duration and who are willing
to provide verbal and informed consent. Patients will answer a questionnaire regarding pain
and functional improvement especially in reference to misoprostol treatment. Patients will
also be selected to have their walking tolerance (claudication distance) measured in an
outpatient clinic setting to determine the severity of their lumbar spinal stenosis symptoms
after having received misoprostol.
Description:
Lumbar spinal stenosis (LSS) is clinically described as a neurogenic claudication that is
associated with increased mechanical compression on the spinal nerve roots as well as
potential compromise of the vascular supply of the spinal nerve roots. This compression
typically leads to symptoms of lumbar pseudoclaudication, which include pain, paresthesias,
and discomfort in the lower extremities, commonly exacerbated by walking. Broadly speaking,
this compression can be the result of a degenerative narrowing of the spinal or nerve root
canals. While spinal stenosis is typically considered idiopathic, causes can also include
malignancy, injury, and chronic inflammation. It is often debilitating to patients and can
lead to a wide variety of negative health outcomes (pre-operative lower levels of function,
psychological distress, high self-reported disability scores and operative risks of surgical
correction) related to attempted surgical correction of lumbar spinal stenosis. Spinal
stenosis continues to be a leading indication for spine surgery in adults older than 65 years
old. Furthermore, estimated total Medicare costs for surgeries treating lumbar spinal
stenosis amounted to over $1.65 billion for 37,598 individual operations.
Physiologically, the venous blood flow in the lumbar spinal region is disproportionately
affected by pressure gradients generated secondary to normal movement and pathologic
constriction. Studies have found that patients diagnosed with lumbar spinal stenosis with
intermittent claudication, while walking on a treadmill, experienced larger amounts of
vascular congestion which resolved with sitting. This was measured with a myeloscope in the
intrathecal space.
The current vascular pathologic mechanism of the symptomatic effects of lumbar spinal
stenosis is thought to be a consequence of constriction leading to increasing vascular
congestion and inflammation. Authors first described the effect of constriction on vascular
flow through a post mortem study of a patient with chronic lumbar spinal stenosis at L4-L5.
Most significantly, they found that venous supply proximal to constriction in fact showed
reduced and collapsed veins with gross congestion proximal to the lesion. Further
investigation found that venous congestion led to increased inflammatory markers in nerves
with atrophy, Wallerian degeneration, and perineural fibrosis in more severe patients. Most
importantly, these pathologic changes were associated with vascular changes in the absence of
direct nerve root compression at these sites. This venous congestion is a potential target
for therapy.
There has been previous work done with medications that are PGE1 analogs such as limaprost
and lipo-PGE1. PGE1 analogs hypothetically treat the above lumbar spinal stenosis pathology
by improving blood flow to nerve roots through vasodilatory and antiplatelet aggregation
effects. However, misoprostol (PGE1 analog) has not been thoroughly evaluated as a possible
treatment for symptoms of lumbar spinal stenosis.