Microendoscopic suture of incidental durotomy and its
influence on surgical outcomes in patients undergoing
microendoscopic lumbar surgery
Kazuhito Soma, MD,1,2 Yasushi Oshima, MD, PhD,2 Hiroyuki Oka, MD, PhD,2 Ko Matsudaira, MD, PhD,2 Hisashi Koga, MD, PhD,1
Yuichi Takano, MD, PhD,1 Hiroki Iwai, MD, PhD,1 Masayoshi Fukushima, MD,1 Sakae Tanaka, MD, PhD,2 Hirohiko Inanami, MD,1
1Iwai
Orthopaedic Medical Hospital, 2The University of Tokyo Hospital,
【Background】
【Conclusion】
Microendoscopic spine surgery has been widely conducted as minimally invasive surgery for spinal diseases.
Microendoscopic surgery is less invasive than open lumbar spine surgery, and duration of hospital stays is shorter.
Because of it, needs of patients for microendoscopic surgery is becoming higher.
Dural tear is one of the most common complications in microendoscopic spine surgery, and sometimes pretty difficult to
repair under the total microendoscopic procedure, which might require conversion to open surgery. Therefore, it is very
important to know the risk, management, and influence of dural tears in microendoscopic spine surgery. Influence of dural
tears on surgical outcomes was investigated in patients who responded to the questionnaire using a propensity-matched
analysis.
The purpose of this study is to investigate the incidence and influence of dural tears in microendoscopic spine surgery.
This study demonstrates that the
questionnaire outcomes are not
influenced with or without dural tear,
when dural tears are properly repaired in
lumbar microendoscopic surgery.
Table 4. Summary of outcome Data
【Material and Methods】
A total of 922 patients underwent
microendoscopic surgery of the lumbar
spine at Iwai Orthopaedic Medical
Hospital between February and
December 2012 (Table1).
Table 1
Sex
male
female
Surgery
MED
MEL
PLIF
Age
total
DTs
DTs
n = 922
690 ( 74.8 % )
232 ( 25.2 % )
474 ( 51.4 % )
271 ( 29.4 % )
177 ( 19.2 % )
66.2 ( SD = 5.83 )
MED, Microendoscopic Disectomy; MEL, Microendoscopic Laminectomy;
PLIF, Posterior Lumbar Interbody Fusion; DTs, Dural tears
Dural tears occurred in 49 patients (5.3 %), of these, 23 patients (2.5 %) required
suture repair of the dura mater under a total microendoscopic procedure (Table 2). In
the rest of 26 cases, there was only a pin hole without a massive cerebrospinal fluid
leakage or the arachnoid membrane was maintained, which merely required fixation
with fibrin glue.
Table 2. Summary of DTs
n = 49
MED
51.4 ( SD = 12.4 )
MEL
68.0 ( SD = 10.9 )
PLIF
66.2 ( SD = 5.83 )
12
2
18
4
5
8
60
44.1
87.8
59.9
157.7
107.6
6
8
9
13
8
5
10.3 ( SD = 5.38 )
10.0 ( SD = 6.25 )
14.6 ( SD = 4.50 )
14
-
14
8
8
5
male
female
Location
ipsilateral side
opposite side
600 patients who responded
to the questionnaire both preand postoperatively, and
dural tears occurred in 38
patients of them. Using the
propensity score-matching
technique, an equal number
of 38 patients without dural
teas were used as a casecontrol comparison group
(Table 3).
no
p
JOA
ODI
NRS
Back Pain
Leg Pain
Dysesthesia Intensity
SF-36
PF
RP
BP
MH
Postoperative
JOA
ODI
NRS
Back Pain
Leg Pain
Dysesthesia Intensity
SF-36
PF
RP
BP
MH
Changes in scores
JOA (%)
12.1
38.6
12.1
36.2
0.28
0.31
4.34
6.22
6.57
4.35
6.42
5.27
0.72
0.68
0.23
51.5
44.4
29.3
52.1
56.6
44.7
27.7
58.8
0.64
0.79
0.88
0.53
16.2
17.0
15.9
17.4
0.85
0.51
2.46
2.47
3.27
2.4
2.28
3.08
0.67
0.61
0.35
76.0
73.0
63.2
62.2
76.5
67.9
58.9
62.9
0.96
0.93
0.46
0.70
24.3
22.5
0.906
JOA indicates Japanese Orthopaedic Association; ODI, Oswestry Disability Index;
PF, Physical Function; RP, Role Physical; BP, Body Pain; MH, Mental Health
Operation time
DTs (+)
DTs (-)
Suture
yes
no
Hospital stay
yes
Preoperative
49 ( 5.3 % )
Age
Sex
n = 38
【Results】
Table 3. Summary of patients data
DTs
no DTs
P
male
26
26
1.00
female
12
12
total
63.6 (SD=12.3)
63.6 (SD=12.3
MED
51.0 (SD=13.1)
51.0 (SD=13.1)
MEL
68.1 (SD=9.2)
68.1 (SD=9.2)
PLIF
68.2 (SD=6.8)
68.2 (SD=9.2)
MED
10
10
MEL
19
19
PLIF
9
9
Sex
Age
1.00
Type of surgery
The pre- and postoperative questionnaire scores are summarized (Table 4).
All patients had a statistically significant improvement from preoperative to
postoperative for all questionnaires. There were no significant differences in
pre- and postoperative NRS for back and leg pain, dysesthesia intensity,
ODI, JOA score, and 36-Item Short Form Health Survey PCS, 36-Item
Short Form Health Survey MCS between the groups.
【Disuccusion】
The strengths of this study were its propensity-matched analysis and the
large number of patients who were included. Repairing the dural sac under
the total microendoscopic procedure, which requires a longer operation time,
is technically demanding, because the small working space available using a
tubular retractor makes suturing the dura difficult. When dural tears occur at
the opposite side of surgical approach, it is technically difficult to repair the
dural sac, which would take a longer time. However, we were able to repair
dural tears under the total microendoscopic procedure in all cases without
converting to the open method.
Since a steep learning curve exists in the microendoscopic surgery,
surgeons require to master surgical skills to prevent and repair dural tears.
1.00
【Surgical technique】
Our technique of repairing dural tears using microendoscopic procedure was as follows: first, we moved a double-arm needle
to suture the dura mater inside-out to prevent nerve damage. Then, we made a knot outside the tube-retractor, and pushed
the knot by a probe, and finally, we covered the tear using fibrin glue.
(A)
(B)
(C)
(D)
(E)
Illustrations showing our technique of repairing
dural tears using microendoscopic procedure.
(A) Black arrow shows the tear.
(B, C) We moved a double-arm needle to suture
the dura mater inside-out to prevent nerve
damage.
(D, E) We made a knot outside the tuberetractor, and pushed the knot by a probe.