Canh
M. Nguyen,
MD
#{149} Victor
Effect of Repeated of Chymopapain Because arachnoiditis occurred in a previous experimental study, the authors performed additional experimental injections of chymopapain in the epidural space. Four monkeys received epidural injections of 100 units of chymopapain in 1.2 mL of saline on days 1, 8, and 16 of the experiment; four control animals received injections of 1.2 mL of 0.9% saline on the same days. Both groups were killed on the 84th day. The dural sac was removed, fixed, sectioned, stained, and exammed microscopically. No significant changes were found in the arachnoid, dura, or epidural space of the treated animals. Chymopapain, even if injected
repeatedly
dural space, cant scarring
into
the
epi-
does not cause signifiin the meninges.
M. Haughton,
pain
terms:
Chemonucleolysis
#{149} Meninges.
35.458,
36.458
174:417-4
19
Radiology
1990;
.
C
HYMOPAPAIN
Ho,
arachnoiditis
injected
was
expeni-
therefore
investi-
MATERIALS Eight
AND
healthy
were assigned The animals (15
mg/kg
cynomolgus
monkeys
randomly were sedated of body
dress C
June
12; revision
reprint RSNA,
14. Supported grant no. ROl
requests 1990
received
July
by National NS 14274-09.
to V.M.H.
31; acInstiAd-
contents
canal
and
prepared. was inserted
of the
ylene
catheter
guide needle
wire and
tail;
an
18-gauge
thinspi-
dune papain
was
and minutes. in the
a fine
1 monkeys
flu-
normal 100
pain
mL
in
catheter was obIf cerebrospinal catheter, the proce-
1.2
Saline through
(controls)
mL of 0.9% keys received
dural sac and the fixed in
received
saline.
1.2
To
of Chymodiactin Northbrook,
obtain Ill)
con-
taming 4,000 units of the enzyme was meconstituted with 2 mL of sterile water; 0.2 mL of the reconstituted enzyme was then diluted with 4.6 mL of 0.9% normal saline. After the epidural injection of the enzyme, the catheter was flushed with 0.2 cm3 of air. The catheter the animal was allowed sedation. The animal to its fitness
cage and observed and neurologic
tions
were
repeated
was removed, and to recover from was then returned daily deficit. at weekly
a total of three injections. At 12 weeks after the first
without
treatment
by
a
knowledge
protocols
of
the
of
animals.
studies:
0, normal
or slight fibrosis
marked changes (Figure). rank sum test was used in the two groups, and
was
chosen
structures;
fibrosis or or inflammation;
for statistical
1, infiltra3,
The Wilcoxon to compare results the level of P 5%
significance.
for general The injecintervals injection,
RESULTS None of the monkeys displayed evidence of seizures, paralysis, on other obvious toxicity due to the epidural injections. In no case did cerebrospinal fluid flow into the catheten. After recovering from sedation, all animals returned to normal activity
within
12-24
hours.
necropsy, gross examination findings in the spinal canal were normal in all monkeys. No granulation tissue in the epidumal space or adhesions or discoloration in the durab sac or lumbar nerve root sheaths was evident. The pathologic changes evident at light microscopy are summarized in the Table. Two animals in group i had changes graded as mild. In one animal (no. 676) slight fibrosis of the arachnoid and mild fibrosis of the duna were found. In another animal (no. 685) mild degeneration of axons and myelin sheaths and slight Schwann cell proliferation were noted in the nerve roots. In group 2 mild fibrosis of the anachnoid space was noted from the level of L-3 to the 1evAt
or chymothe catheter.
saline. Group 2 monpkat units of chymopa-
of normal
canal
to the posterior root ganglia, the and cord were sectioned at T-12, dura! sac was removed carefully, 10% buffered formalin, embedded, mounted, stained, and examined
steel
the
discontinued. was injected
spinal
polyeth-
with
was introduced through that advanced cephalad in the epi-
withdrawn, for 2-3 appeared
lumbar
changes. lateral
questionable tion; 2, mild
acepro-
A 16-gauge into the
stiffened
then served fluid
for
of the
exsanguination A total laminectowas performed, and
were inspected for morphologic The spinal nerves were sectioned
previous
to two groups. with ketamine
weight)
this solution, a vial (Smith Laboratories,
August of Health
the
by
Representative axial sections of the dural sac at L-3, L-4, L-5, and L-6 were scored with the arbitrary grading system used in
METHODS
mazine (i mg/kg). The lower part of the back and the proximal tail were shaved
Group
requested
monkeys were killed under deep anesthesia. my from T-iO to S-4
the
and lateral radiographs were obtained to verify that the catheter was within the central spinal canal. The guide wire was
cepted tutes
PhD
neuropathologist
gated.
dural space to the mid-L-4 level with oroscopic monitoring. Anteropostenior
I From the Departments of Radiology (C.N., V.M.H) and Pathology (K.C.H.), Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital. 9200 W Wisconsin Ave. Milwaukee, WI 53226. Received May 18, 1989; revision
MD,
Space’
mentally into the epidunal space of animals does not regularly cause arachnoiditis (i-li). The exceptional animal in a previous experiment developed anachnoiditis after two injections of the enzyme 6 weeks apart (i). The possibility that multiple injections of the enzyme might cause
and surgically walled needle
Chymopa-
#{149} Khang-Cheng
Injections in the Epidural
nal Index
MD
the
417
c.
b.
a.
‘1
d.
e. Histologic and epidural are normal.
sections illustrating the grading of changes in the arachnoid (solid arrows) space (open arrows); d dura. (a) Dura, epidural space, and arachnoid (b-d) Grade 1, 2, and 3 changes in the arachnoid, respectively. Grade 1, 2, and 3 changes in the epidura! space, respectively.
(e-g)
Findings
after
Repeated
Epidural
Injections
of Chymopapain Maximum
or Saline
Fibrosis
Score* Epidura!
Experimental
DISCUSSION The evaluate for
study the
was not designed to safety of chymopapain
repeated
injections
in
clinical
practice. Multiple injections of chymopapain or injections at two or more disk spaces are not recommended because of increased risk of adverse neurologic events. The
418
.
dose
selected
Radiology
for
this
study
Arachnoid
Group 1 (saline injection) Animal673 Animal675 Animal 676 Animal 685 Group 2 (chymopapain injection) Animal 667 Animal 668 Animal67l Animal672
g. el of L-6 in one animal, and questionable changes were noted in another. The differences between groups 1 and 2 were not statistically significant (P > .10). With the amount and concentrations of chymopapain used, chronic meningeal changes were no greater than those induced by normal saline injected epidurally.
Group
*
Grading
fibrosis
scale:
0
no pathologic
or inflammation,
3
marked
changes fibrosis
evident,
leaks
into
the
epidural
space.
Therefore, we injected 25% of a standand clinical dose (per unit of body weight) into the epidural space of the experimental animals. The enzyme is inactivated rapidly by exposure to macroglobulins
(2,12,13),
in
but
we
the
have
blood
not
observed
Space
Roots
0 1 1 1
0 0 2 0
0 0 0 0
0 0 0 2
2 1 0 0
0 0 0 0
0 0 0 0
0 0 0 0
1
questionable
to slight
abnormality,
2
mild
or inflammation.
represents an amount that may reach the epidural space as a result of chemonucleolysis. Wiltse et al (3) estimated that in one of four patients undergoing chemonucleolysis, chymopapain
Nerve
Dura
bleeding in the epidumab space as a result of epidurab catheterization. Arachnoiditis can be detected even after epidural injections of mild irnitants, and statistically significant differences can be detected (1) in groups of experimental animals as small as those
used
in
this
study.
We
found
no evidence in the two groups of traumatic changes resulting from catheterization and no significant evidence of fibrosis secondary to injection
of
the
enzyme.
February
1990
Most not
experimental
demonstrated
that
produces arachnoiditis some studies, nerve tion
has
been
studies have chymopapain (2-4,6-11). root degenena-
attributed
to
3.
In
chymopa-
itis
6.
been
detected
in
receiving chymopapain. The data from the present study add more evidence that if chymopapain reaches the epidural space, it does not cause anachnoiditis on nerve root degeneration. U
8.
Haughton
VM,
Effect
of chymopapain
studied 2.
Nguyen-minh
in
an
Chymopapain:
toxicologic imals.
on
experimental
ogy 1988; 169:475-478. Garvin PJ, Jennings
RM.
Orthop
the
KC.
meninges
model.
in experimental 1965;
46:204-223.
9.
an-
10.
Volume
174
#{149} Number
2
Chymo-
12.
disc
231:474-478.
nerve
injury
by
chymopapain
nerves
and
intervertebral
Rydevik
B, Barnemark
after
pain. Spine Widdowson
local
15.
discs
of
P. Norberg
of chymopa-
1976; WL.
Tissue
response
Einarson
TR,
Bootman
JL,
Smith
GH.
Chymopapain. Drug Intel! Clin Pharm 1984; 18:560-568. Stern IJ. Biochemistry of chymopapain. C!in Orthop 1969; 67:42-46. Smith L, Brown JE. Treatment of lumbar intervertebral disc lesions by direct injections of chymopapain. J Bone Joint Surg [Br] 1967; 49:502-517. Weitz EM. Paraplegia following chymopapain injection. J Bone Joint Surg [Am] 1984; 7:1131-1135.
16.
Eguro H. Transverse myelitis chemonucleolysis. J Bone Joint
17.
Agre
18.
DJ. Chymodiactin lance demographic ence data in 29,075 9:480-485. Brown JE, Nordby
following Surg [Am]
1983; 65:1328-1330.
C,
3:137-148. Effects of chymopapain in the intervertebral disc of dog. J Am Vet Assoc 1967; 150:608-617. Branemark P1, Ekholm R, Lundskog J, C.
14.
Efon
J, Foge!berg M. Efon nerve tissue: an on the structure and nerve tissue in rab-
application
13.
in-
Cynomolgus monkeys. J Neurosurg 1986; 64:474-483. McNab I, McCulloch JA, Weiner DS, Hugo EP, Galway RD. Dali D. Chemonucleolysis. Can J Surg 1971; 14:280-288.
Hirsh
11.
HA.
jection. J Neurosurg 1984; 61:1-8. Zook C, Bernard DVM, Koprine Al. fects of col!agenase and chymopapain
bits
Radiol-
RB. Smith L, Gesler a pharmacologic and
evaluation Clin
C. Ho
Yuan
in lumbar
1975;
McLean G, Sjostrand fects of chymopapain experimental study function of peripheral
References 1.
JAMA
spinal
7.
EH,
Ford LT. Experimental study of chymopapain in cats. Clin Orthop Re! Res 1969; 67:68-71. Mackinnon SE, Hudson AR, Llamas F, Dellon AL, Kline DG, Hunter DA. Peripheral
patients
Widell
chemonucleolysis
disease.
4.
5.
not
LL,
papain
pain (6,8). Although adverse effects of chymopapain have been demonstrated clinically (14-19), anachnoidhas
Wiltse
K, Wilson
nucleolysis.
19.
RR,
Thorofare,
Brim
M,
McDermott
postmarketing surveiland adverse experipatients. Spine 1984; EJ, Smith NJ:
L. Slack,
Chemo1985.
Cusick JF, Ho KC, Schamberg JF. Subarachnoid hemorrhage following chymopapain chemonucleolysis: case report. Neurosurg 1987; 66:775-778.
to chymopa-
pain in different concentrations. Clin Orthop 1969; 67:52-65. Shealy CN. Tissue reactions to chymopapain in cats. J Neurosurg 1967; 26:327-330.
Radiology
#{149} 419
M. Nguyen,
MD
#{149} Victor
Effect of Repeated of Chymopapain Because arachnoiditis occurred in a previous experimental study, the authors performed additional experimental injections of chymopapain in the epidural space. Four monkeys received epidural injections of 100 units of chymopapain in 1.2 mL of saline on days 1, 8, and 16 of the experiment; four control animals received injections of 1.2 mL of 0.9% saline on the same days. Both groups were killed on the 84th day. The dural sac was removed, fixed, sectioned, stained, and exammed microscopically. No significant changes were found in the arachnoid, dura, or epidural space of the treated animals. Chymopapain, even if injected
repeatedly
dural space, cant scarring
into
the
epi-
does not cause signifiin the meninges.
M. Haughton,
pain
terms:
Chemonucleolysis
#{149} Meninges.
35.458,
36.458
174:417-4
19
Radiology
1990;
.
C
HYMOPAPAIN
Ho,
arachnoiditis
injected
was
expeni-
therefore
investi-
MATERIALS Eight
AND
healthy
were assigned The animals (15
mg/kg
cynomolgus
monkeys
randomly were sedated of body
dress C
June
12; revision
reprint RSNA,
14. Supported grant no. ROl
requests 1990
received
July
by National NS 14274-09.
to V.M.H.
31; acInstiAd-
contents
canal
and
prepared. was inserted
of the
ylene
catheter
guide needle
wire and
tail;
an
18-gauge
thinspi-
dune papain
was
and minutes. in the
a fine
1 monkeys
flu-
normal 100
pain
mL
in
catheter was obIf cerebrospinal catheter, the proce-
1.2
Saline through
(controls)
mL of 0.9% keys received
dural sac and the fixed in
received
saline.
1.2
To
of Chymodiactin Northbrook,
obtain Ill)
con-
taming 4,000 units of the enzyme was meconstituted with 2 mL of sterile water; 0.2 mL of the reconstituted enzyme was then diluted with 4.6 mL of 0.9% normal saline. After the epidural injection of the enzyme, the catheter was flushed with 0.2 cm3 of air. The catheter the animal was allowed sedation. The animal to its fitness
cage and observed and neurologic
tions
were
repeated
was removed, and to recover from was then returned daily deficit. at weekly
a total of three injections. At 12 weeks after the first
without
treatment
by
a
knowledge
protocols
of
the
of
animals.
studies:
0, normal
or slight fibrosis
marked changes (Figure). rank sum test was used in the two groups, and
was
chosen
structures;
fibrosis or or inflammation;
for statistical
1, infiltra3,
The Wilcoxon to compare results the level of P 5%
significance.
for general The injecintervals injection,
RESULTS None of the monkeys displayed evidence of seizures, paralysis, on other obvious toxicity due to the epidural injections. In no case did cerebrospinal fluid flow into the catheten. After recovering from sedation, all animals returned to normal activity
within
12-24
hours.
necropsy, gross examination findings in the spinal canal were normal in all monkeys. No granulation tissue in the epidumal space or adhesions or discoloration in the durab sac or lumbar nerve root sheaths was evident. The pathologic changes evident at light microscopy are summarized in the Table. Two animals in group i had changes graded as mild. In one animal (no. 676) slight fibrosis of the arachnoid and mild fibrosis of the duna were found. In another animal (no. 685) mild degeneration of axons and myelin sheaths and slight Schwann cell proliferation were noted in the nerve roots. In group 2 mild fibrosis of the anachnoid space was noted from the level of L-3 to the 1evAt
or chymothe catheter.
saline. Group 2 monpkat units of chymopa-
of normal
canal
to the posterior root ganglia, the and cord were sectioned at T-12, dura! sac was removed carefully, 10% buffered formalin, embedded, mounted, stained, and examined
steel
the
discontinued. was injected
spinal
polyeth-
with
was introduced through that advanced cephalad in the epi-
withdrawn, for 2-3 appeared
lumbar
changes. lateral
questionable tion; 2, mild
acepro-
A 16-gauge into the
stiffened
then served fluid
for
of the
exsanguination A total laminectowas performed, and
were inspected for morphologic The spinal nerves were sectioned
previous
to two groups. with ketamine
weight)
this solution, a vial (Smith Laboratories,
August of Health
the
by
Representative axial sections of the dural sac at L-3, L-4, L-5, and L-6 were scored with the arbitrary grading system used in
METHODS
mazine (i mg/kg). The lower part of the back and the proximal tail were shaved
Group
requested
monkeys were killed under deep anesthesia. my from T-iO to S-4
the
and lateral radiographs were obtained to verify that the catheter was within the central spinal canal. The guide wire was
cepted tutes
PhD
neuropathologist
gated.
dural space to the mid-L-4 level with oroscopic monitoring. Anteropostenior
I From the Departments of Radiology (C.N., V.M.H) and Pathology (K.C.H.), Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital. 9200 W Wisconsin Ave. Milwaukee, WI 53226. Received May 18, 1989; revision
MD,
Space’
mentally into the epidunal space of animals does not regularly cause arachnoiditis (i-li). The exceptional animal in a previous experiment developed anachnoiditis after two injections of the enzyme 6 weeks apart (i). The possibility that multiple injections of the enzyme might cause
and surgically walled needle
Chymopa-
#{149} Khang-Cheng
Injections in the Epidural
nal Index
MD
the
417
c.
b.
a.
‘1
d.
e. Histologic and epidural are normal.
sections illustrating the grading of changes in the arachnoid (solid arrows) space (open arrows); d dura. (a) Dura, epidural space, and arachnoid (b-d) Grade 1, 2, and 3 changes in the arachnoid, respectively. Grade 1, 2, and 3 changes in the epidura! space, respectively.
(e-g)
Findings
after
Repeated
Epidural
Injections
of Chymopapain Maximum
or Saline
Fibrosis
Score* Epidura!
Experimental
DISCUSSION The evaluate for
study the
was not designed to safety of chymopapain
repeated
injections
in
clinical
practice. Multiple injections of chymopapain or injections at two or more disk spaces are not recommended because of increased risk of adverse neurologic events. The
418
.
dose
selected
Radiology
for
this
study
Arachnoid
Group 1 (saline injection) Animal673 Animal675 Animal 676 Animal 685 Group 2 (chymopapain injection) Animal 667 Animal 668 Animal67l Animal672
g. el of L-6 in one animal, and questionable changes were noted in another. The differences between groups 1 and 2 were not statistically significant (P > .10). With the amount and concentrations of chymopapain used, chronic meningeal changes were no greater than those induced by normal saline injected epidurally.
Group
*
Grading
fibrosis
scale:
0
no pathologic
or inflammation,
3
marked
changes fibrosis
evident,
leaks
into
the
epidural
space.
Therefore, we injected 25% of a standand clinical dose (per unit of body weight) into the epidural space of the experimental animals. The enzyme is inactivated rapidly by exposure to macroglobulins
(2,12,13),
in
but
we
the
have
blood
not
observed
Space
Roots
0 1 1 1
0 0 2 0
0 0 0 0
0 0 0 2
2 1 0 0
0 0 0 0
0 0 0 0
0 0 0 0
1
questionable
to slight
abnormality,
2
mild
or inflammation.
represents an amount that may reach the epidural space as a result of chemonucleolysis. Wiltse et al (3) estimated that in one of four patients undergoing chemonucleolysis, chymopapain
Nerve
Dura
bleeding in the epidumab space as a result of epidurab catheterization. Arachnoiditis can be detected even after epidural injections of mild irnitants, and statistically significant differences can be detected (1) in groups of experimental animals as small as those
used
in
this
study.
We
found
no evidence in the two groups of traumatic changes resulting from catheterization and no significant evidence of fibrosis secondary to injection
of
the
enzyme.
February
1990
Most not
experimental
demonstrated
that
produces arachnoiditis some studies, nerve tion
has
been
studies have chymopapain (2-4,6-11). root degenena-
attributed
to
3.
In
chymopa-
itis
6.
been
detected
in
receiving chymopapain. The data from the present study add more evidence that if chymopapain reaches the epidural space, it does not cause anachnoiditis on nerve root degeneration. U
8.
Haughton
VM,
Effect
of chymopapain
studied 2.
Nguyen-minh
in
an
Chymopapain:
toxicologic imals.
on
experimental
ogy 1988; 169:475-478. Garvin PJ, Jennings
RM.
Orthop
the
KC.
meninges
model.
in experimental 1965;
46:204-223.
9.
an-
10.
Volume
174
#{149} Number
2
Chymo-
12.
disc
231:474-478.
nerve
injury
by
chymopapain
nerves
and
intervertebral
Rydevik
B, Barnemark
after
pain. Spine Widdowson
local
15.
discs
of
P. Norberg
of chymopa-
1976; WL.
Tissue
response
Einarson
TR,
Bootman
JL,
Smith
GH.
Chymopapain. Drug Intel! Clin Pharm 1984; 18:560-568. Stern IJ. Biochemistry of chymopapain. C!in Orthop 1969; 67:42-46. Smith L, Brown JE. Treatment of lumbar intervertebral disc lesions by direct injections of chymopapain. J Bone Joint Surg [Br] 1967; 49:502-517. Weitz EM. Paraplegia following chymopapain injection. J Bone Joint Surg [Am] 1984; 7:1131-1135.
16.
Eguro H. Transverse myelitis chemonucleolysis. J Bone Joint
17.
Agre
18.
DJ. Chymodiactin lance demographic ence data in 29,075 9:480-485. Brown JE, Nordby
following Surg [Am]
1983; 65:1328-1330.
C,
3:137-148. Effects of chymopapain in the intervertebral disc of dog. J Am Vet Assoc 1967; 150:608-617. Branemark P1, Ekholm R, Lundskog J, C.
14.
Efon
J, Foge!berg M. Efon nerve tissue: an on the structure and nerve tissue in rab-
application
13.
in-
Cynomolgus monkeys. J Neurosurg 1986; 64:474-483. McNab I, McCulloch JA, Weiner DS, Hugo EP, Galway RD. Dali D. Chemonucleolysis. Can J Surg 1971; 14:280-288.
Hirsh
11.
HA.
jection. J Neurosurg 1984; 61:1-8. Zook C, Bernard DVM, Koprine Al. fects of col!agenase and chymopapain
bits
Radiol-
RB. Smith L, Gesler a pharmacologic and
evaluation Clin
C. Ho
Yuan
in lumbar
1975;
McLean G, Sjostrand fects of chymopapain experimental study function of peripheral
References 1.
JAMA
spinal
7.
EH,
Ford LT. Experimental study of chymopapain in cats. Clin Orthop Re! Res 1969; 67:68-71. Mackinnon SE, Hudson AR, Llamas F, Dellon AL, Kline DG, Hunter DA. Peripheral
patients
Widell
chemonucleolysis
disease.
4.
5.
not
LL,
papain
pain (6,8). Although adverse effects of chymopapain have been demonstrated clinically (14-19), anachnoidhas
Wiltse
K, Wilson
nucleolysis.
19.
RR,
Thorofare,
Brim
M,
McDermott
postmarketing surveiland adverse experipatients. Spine 1984; EJ, Smith NJ:
L. Slack,
Chemo1985.
Cusick JF, Ho KC, Schamberg JF. Subarachnoid hemorrhage following chymopapain chemonucleolysis: case report. Neurosurg 1987; 66:775-778.
to chymopa-
pain in different concentrations. Clin Orthop 1969; 67:52-65. Shealy CN. Tissue reactions to chymopapain in cats. J Neurosurg 1967; 26:327-330.
Radiology
#{149} 419
