The following information represents our experience with and
philosophy for the management of a particularly difficult and
relatively rare problem. In this disease there are no two patients
who will be identical; however, some clear generalizations can be
made. We hope that the foregoing is of value in helping to explain
all of this.
We have developed considerable experience as a result of evaluating
many patients with symptomatic lumbar adhesive arachnoiditis who have
been referred to us following a previous surgical procedure for disc
disease and/or decompression for lumbar spinal stenosis. Over fifty
(50) of these patients have undergone microsurgical intradural
neurolysis and insertion of a dural decompressive patch graft
since 1973. The indications for investigation and surgical treatment
have been significant, persistent pain and neurological deficit
following "disc surgery" or "decompression" particularly if there
was a history or evidence of a dural laceration. On occasion,
postoperative patients have been referred with severe incapacitating
pain as the primary problem. Progressive loss of neurological
function, particularly bladder control, has also been a cause for
referral and among the indications for surgery.
The operation consists of a wide laminectomy extending to just
above the level of arachnoidal involvement. Microsurgical neurolysis
of the cauda equina then follows. An attempt is made to free each
nerve root to its exit zone. However, in some cases with extensive
matting this may be incompletely accomplished. With rare exception,
these patients undergo some form of dural patch grafting in an effort
to prevent further scarring of the roots and adhesions to the dura.
This has been an important feature of the treatment since it allows
for the re-establishment of cerebrospinal fluid circulation around
the nerve roots and thus reduces the risk for recurrence of scarring.
Females and males have been affected equally. All patients, except
one, had undergone previous lumbar operative procedures. Sixty (60%)
percent of patients had multiple lumbar spinal operations prior to
this operation. Although all of the patients had previous myelograms,
75% of them had two or more myelograms prior to referral. Two (2)
patients had a previous chemonucleolysis and six (6) had intrathecal
steroids injected. One patient underwent myeloscopy in addition to
having suffered a dural laceration and having undergone seven
intrathecal steroid injections and myelographic procedures before
being referred to us from Canada.
The single patient who did not undergo a previous lumbar spine
operation seems to have developed arachnoiditis consequent to four
(4) Pantopaque myelograms which were initially done for cervical
disc disease prior to referral. Twenty-five percent (25%) of
patients were known to have suffered dural laceration at the time
of their previous procedures. Four (4) patients (including 2 with
dural lacerations) suffered disastrous neurological sequelae prior
to referral. All of the patients had severe pain as a major
preoperative complaint. At least 25% of patients had bladder and
rectal sphincter dysfunctions. Two (2) of these were incontinent.
Patients were divided into three categories, according to the
extent and severity of arachnoidal involvement and degree of
disability. Involvement of more than three vertebral levels
constituted the "severely" involved group and included 50% of
patients. Involvement of 2 to 3 vertebral levels constituted the
"moderately" involved group and included 30% patients. Involvement
at one vertebral level constituted the "mild" group and included
20% of patients.
In assessing our results, we have noted that 40% of patients in
the "severe" category, 65% of the patients in the "moderate"
category and 85% in the "mild" category have had a "good" result.
(They have minimal or no pain which is easily controlled with
non-narcotic analgesics.) They are either capable of or have
returned to work or full regular activities. A "fair" result was
characterized as persistent pain which was substantially less
than the preoperative condition and controlled by medication.
This "fair" result was achieved in 33% of patients in the "severe"
group, 35% in the "moderate" group and 15% in the "mild" group.
All patients who suffered preoperative bladder disabilities
enjoyed improvement of function except for those who were
incontinent preoperatively. The patients in the "severe" group
had the most extensive cauda equina involvement and consequently
demonstrated the least improvement. Eighty-five percent (85%) of
patients in the "severe" group had significant neurological
deficits preoperatively. All patients in the "severe" category
still had some pain postoperatively requiring medication. One
patient's neurological deficit was worse postoperatively. While
all the other patients are improved after surgery, the improvement
in 27% of the "severe" group is limited and their overall result
is considered to be poor. Thirty-three percent (33%) of patients
with severe preoperative neurological deficit are improved
postoperatively. Thirty percent (30%) of patients still use
crutches or a cane to assist ambulation.
The 30% of all patients who were assigned to the "moderate" group
were primarily concerned with pain and had mild neurological
deficit preoperatively. All are improved postoperatively but
with persistent mild or intermittent pain. The neurological
deficits improved postoperatively to a nearly normal status. The
20% of all patients placed in the "mild" category all had severe
pain preoperatively but only two had neurological deficit.
Sixty-five percent (65%) are pain-free postoperatively, while
35% have mild pain.
A "poor" result was noted in 27% of patients in the "severe" group.
Although there may have been some improvement in the pain relief
and preoperative neurological status, it was minimal. Overall an
88% improvement in the patients' pain and neurological deficits
were noted. Of those patients, 58% needed to return to the
work force, 42% were able to do so. Another 36% of the patients
were either involved in housework or are retired. Maximum
improvement was generally noted to have been achieved by one
year postoperatively. There have been three cases of worsening
status and documented progression of the arachnoiditis on
long-term follow-up. One case involved extension of the
arachnoiditis above the level of our initial neurolysis procedure
while the other was a similar extension of the arachnoiditis
below the operative site. One other case experienced recurrence
of pain and scarring (at the operative site) within two months
of an initial neurolysis. All three patients underwent a repeat
operation and have improved.
The major complication was the occurrence of cerebrospinal
fluid leakage postoperatively in relation to the dural graft. This
occurred in 17% of patients. Repeat operations for closure of
the fistula were carried out in each instance. One of these
patients developed a postoperative wound infection which
responded to appropriate antibiotics. Another patient received
a one unit blood transfusion and two months later presented
with serum hepatitis.
Inspection of the previous operative area beneath the silastic
dural reconstruction graft in two of the patients demonstrated
a satisfactory situation characterized by a lack of scarring.
A "pseudo-dura" forms beneath the silastic but is separated from
the cauda equina by cerebrospinal fluid. Five (5) patients have
undergone postoperative myelography. We have been reluctant to
carry out this procedure unless there has been a strong
neurosurgical indication (such as suspected cerebrospinal fluid
fistula) since we would prefer to limit the introduction of any
instrumentation or agents which could be related to the etiology
There are several aspects of this difficult clinical problem that
have impressed us. Causative factors seem to have been surgical
misadventures during lumbar disc operations with either
over-zealous retraction of nerve roots or the laceration of dura
along with injury to the arachnoid. Additionally, there seemed
to be some relationship to the use of oil-based myelographic dyes
which are no longer available. We have been very impressed by
the extent of scarring associated with the use of intrathecal
steroids. The "carrier" substance has been found to be imbedded
in very dense scar around matted nerve roots and in several
instances was directly involved in an intradural ossification
process which incorporated the nerve roots as well. This has led
us to strongly caution against the use of intrathecal steroids
for any reason.
There have been several cases referred to us where the lumbar nerve
roots were found in dense scar outside the dura. Most of these
patients had undergone a surgical procedure for a herniated
lumbar disc up to five or ten years previously.
Postoperative cerebrospinal fluid fistula indicates an injury to
the arachnoid membrane. There is a small risk that this could
lead to arachnoiditis at a later date. Injuries to the pia mater
(usually by surgical trauma) can lead to the development of
arachnoiditis as can rare cases of intradural bacterial infection.
Our present policy when considering potential surgical candidates
requires recent myelography with post-myelographic, high-resolution
CT scanning as well as urodynamic studies. Most candidates for
surgery must have either well documented advancing neurological
deficit resulting from the arachnoiditis and/or incapacitating,
agonizing pain that has not responded to aggressive reasonable
methods of management. We are aware that early intervention may
limit the spread of the arachnoiditis. It has been clear to us
that when three or more lumbar levels are involved with this process,
that the results are not nearly so satisfactory. We now have up to
30 years follow up on patients with the results being reliable
and successful in cases where the original result was positive for
the relief of symptoms.
- Lumbar Adhesive Arachnoiditis. Letter to the editor,
Neurosurgery 5:771-772, 1979 Lazar, M.L. and Bland, J.E.
- Treatment of Pain Syndromes. Current Treatment of
Neurological Diseases edited by Rosenberg, R., Spectrum
Publications, Jamaica, NY, 1979, pp. 526-604. Bland, J.E.,
Lazar, M.L. and Naarden, A.L.
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