Keywords
GCS (Glasgow Coma Scale) - GOS (Glasgow Outcome Scale) - nonwatertight dural closure
- watertight dural closure - decompressive craniectomy
Introduction
High intracranial pressure (ICP) is a critical issue encountered in neurosurgery.
It is defined as an ICP raised above the level of 20 mm Hg, which is measured “within
the subdural, intraventricular, or intraparenchymal compartments.”[1]
The incidence of raised ICP is significantly associated with traumatic brain injury
(TBI), which can occur when a force transmitted to the head or body results in neuropathological
damage and neurological dysfunction that manifests as either new-onset or worsening
of at least one of the following clinical signs: any period of loss of or decreased
level of consciousness, any loss of memory, any alteration in mental state (confusion
or disorientation or slowed thinking, etc.), neurological deficits (weakness, loss
of balance, change in vision, praxis, paresis, plegia, sensory loss, aphasia), that
may or may not be transient, or intracranial lesion.[2]
In many situations, primary watertight (WT) dural closure could not be done,[3]
[4]
[5]
[6]
[7] and in others, the dura is left intentionally open as in extraintracranial bypass
surgery the dura is completely excised over the cortical area of anastomosis between
the superficial temporal and recipient cortical arteries without increased risk of
cerebrospinal fluid (CSF) leak or wound infection.[8]
[9]
[10]
With the recent advancements in the management and resuscitative measures, morbidity
and mortality associated with high ICP and its incidence per se, has been brought
down, especially in TBI. The primary focus is to maintain the ICP and cerebral perfusion
pressure, thereby preventing secondary brain injury.[1]
Decompressive craniectomy (DC) remains a primary modality to treat refractory elevated
ICP that is unresponsive to medical management. TBI, middle cerebral artery (MCA)
infarction, and aneurysmal subarachnoid hemorrhage (SAH) are three conditions for
which DC has been predominantly used in the past.[1] DC improves brain tissue perfusion and oxygenation, as well as improving patient
outcomes when performed for MCA stroke and TBI.[2]
[11]
[12]
DC is performed together with dura opening, and it was believed that this could maximize
brain expansion after removal of part of the skull. However, opening the dura with
no protection for the underlying brain tissue may increase the risk of several secondary
surgical complications and CSF leakage through the scalp incision or contralateral
intracranial lesion.[2]
[11]
[12]
[13]
[14]
Nowadays, DC combined with duraplasty is widely performed and is recommended. The
dura suturing technique is traditionally known to require WT closure to prevent complications
such as CSF leakage and infection.
Several studies have reported that nonwatertight (NWT) duraplasty may also be used
as an alternate procedure after DC because NWT duraplasty can reduce the operative
time while the probability of complications remains the same.[2]
The present study was conducted to compare the efficacy, surgical time, and complications
between the two surgical interventions: WT duraplasty and without WT duraplasty (rapid-closure
DC).
Aims and Objectives
To compare the safety and efficacy of two surgical techniques—WT dural closure and
NWT dural closure for DC by comparing the incidence of postoperative complications,
clinical outcome, average blood loss, and average operative time.
Materials and Methods
Study design: A prospective randomized comparative study was conducted from May 15,
2021 to April 15, 2022 at the department of neurosurgery of a tertiary care hospital
in India. Using the block randomization method, a total of 56 patients were included
(28 patients per group: group WT including those undergoing WT dural closure and group
NWT undergoing NWT dural closure).
Study population: Patients with indication for DC including TBI, infarction, aneurysmal
SAH, and dural venous sinus thrombosis were registered from the department of neurosurgery.
Inclusion criteria: Adult patients of both genders with indication for DC including
TBI, infarction, aneurysmal SAH, and dural venous sinus thrombosis.
Exclusion criteria: Patients who had previously undergone any surgical treatment for
other brain lesions, patients with interaxial contusions or hematomas requiring surgical
evacuation with risk of CSF leak, patients planned for posterior fossa surgery, or
patients suffering with polytrauma.
The study was ethically approved by the institutional ethical committee. All study
participants provided their written informed consent. At every stage, privacy and
confidentiality were guaranteed.
Sampling Methodology
Sample size: The values as reference were taken from the study of Vieira et al,[15] assuming standard deviation (SD) of 40 minutes, the minimum required sample size
with 80% power of study and 5% level of significance was 27 patients in each study
group. To reduce margin of error, total sample size taken was 56 (28 patients per
group).
Sampling method: Block randomization was done with sealed envelope system where eight
sealed opaque envelopes were prepared and assigned as A and B in 4 envelopes each,
where A represented group WT and B represented group NWT. Once a patient consented
to enter a trial, an envelope was opened, and the patient was then offered the allocated
group. In this technique, patients were randomized in a series of blocks of eight.
So basically, there were 7 blocks, and, in each block, 8 patients were taken and among
those 8 patients, 4 patients were allocated in the WT group and 4 patients were allocated
in the NWT group.
Methodology of Data Collection
The patients were fully explained about the procedure and approvals were taken with
patient information sheet and the informed consent form. The demographic parameters
such as age, gender, and comorbidities were noted. Detailed record was taken including
vitals (pulse rate, systolic blood pressure [SBP], diastolic blood pressure [DBP])
and anisocoria, and operative parameters included operative time and blood loss. The
patients' details were recorded as per study pro forma. Lax duraplasty (WT/NWT) was
performed with pericranium patch as per the intervention group. Wound was closed in
layers after placement of subgaleal drain. A linear incision was performed in the
designated area of the right lower quadrant of the abdomen. A monopolar was used to
create a pocket of adequate size within Camper's fascia. The bone flap was introduced
with convex side out into the subcutaneous pocket and the wound was closed in layers.
Outcome measures assessed included operative time, blood loss, postoperative Glasgow
Coma Scale (GCS) score, Glasgow Outcome Scale (GOS) score in the follow-up, hospital
stay, and mortality, and the follow-ups of the patients were done at 1, 2, and 3 months
for GOS score.
GCS score assessed preoperatively and postoperatively the severity of consciousness
impairment. The scale rates patients based on their eye-opening, motor, and verbal
responses—the three components of responsiveness. “Best eye response (E), best verbal
response (V), and best motor response (M)” are the three components of the GCS. The
GCS's response levels are “scored” on a scale of 1 for no response to 4 for eye-opening,
5 for verbal response, and 6 for motor response. Thus, the total GCS score ranges
from 3 to 15, with 3 being the worst and 15 being the best.[16]
GOS score was assessed for the follow-up outcomes to evaluate the overall outcome
following severe brain injury.
Routine neuroimaging (computed tomography head) was done from 5th to 10th postoperative
day. Patients were assessed for incidence of complications, namely, CSF leak (CSF
drainage through surgical wound), subgaleal fluid collections and ipsilateral/contralateral
subdural hygroma (CSF drainage to the subcutaneous/epidural space, but not through
surgical wound), wound infection (limited to the subcutaneous/epidural space), or
brain abscess (infection involving the brain parenchyma) and were compared between
the two groups.
Data Compilation Presentation and Analysis
The information collected was tabulated and analyzed using standard statistical software
(SPSS) version 25. Data was compiled on Microsoft Excel version 2010 and was presented
in tabular form. The presentation of the categorical variables was done in the form
of number and percentage (%). On the other hand, the quantitative data were presented
as means ± SD and as median with 25th and 75th percentiles (interquartile range).
The data normality was checked by using the Kolmogorov–Smirnov test. The cases in
which the data was not normal, nonparametric tests were used. To compare the quantitative
variables, the Mann–Whitney test (variables which were quantitative and not normally
distributed) and independent t-test (variables which were quantitative and normally distributed) were used. To compare
qualitative variables the chi-square test and Fisher's exact test (cell had an expected
value of less than 5) were used. For statistical significance, a p-value of less than 0.05 was considered statistically significant.
Results
Sixty-eight patients were assessed for eligibility out of which five were excluded
due to not meeting the inclusion criteria and seven declined to participate in the
study. Of the remaining 56 patients, 28 were assigned to each group. A total of 28
patients each were analyzed for operative characteristics and postoperative complications,
while GOS outcomes was done in 25 patients in group A and 27 patients in group B ([Fig. 1]).
Fig. 1 Flowchart of the study.
Fifty-six patients within the range of 16 to 84 years were included. Thirty-six patients
were male. In the WT group, hypertension was present in 5 patients and diabetes mellitus
was present in 4 cases, while in the NWT group, both diabetes mellitus and hypertension
were present in 5 patients each. Compared with group WT, NWT had significantly lesser
operative time (200.36 ± 39.09 vs. 263.21 ± 33 minutes, p < 0.0001), showing that the morbidity associated with the operation was controlled
faster in the NWT group ([Table 1]). The mean preoperative GCS was 7.25 ± 2.15 in the WT group, while in the NWT group
it was 7.36 ± 1.97. Twenty-eight patients were randomized to each group ([Table 2]).
Table 1
Patients characteristics
|
Variables
|
WT group (n = 28)
|
NWT group (n = 28)
|
p-Value
|
|
Age (mean ± SD)
|
44.5 ± 16.28
|
45.79 ± 20.33
|
0.795
|
|
Gender
|
|
Female (%)
|
9 (32.14%)
|
11 (39.29%)
|
0.577
|
|
Male (%)
|
19(67.86%)
|
17 (60.71%)
|
|
Associated comorbidities
|
|
No comorbidities
|
22(78.57%)
|
20 (71.43%)
|
0.537
|
|
Diabetes mellitus
|
4 (14.29%)
|
5 (17.86%)
|
1
|
|
Hypertension
|
5 (17.86%)
|
5 (17.86%)
|
1
|
|
Type of index diseases
|
|
Traumatic brain injury
|
12 (42.8%)
|
14 (50%)
|
0.7
|
|
Cerebral infarction
|
9 (32.1%)
|
8 (28.5%)
|
0.8
|
|
Aneurysmal SAH
|
3 (10.7%)
|
3 (10.7%)
|
0.1
|
|
Dural vein thrombosis
|
4 (14%)
|
3 (10.7%)
|
0.7
|
|
Vitals
|
|
Pulse rate (mean ± SD)
|
95.32 ± 12.82
|
97.11 ± 13.06
|
0.608
|
|
SBP (mean ± SD)
|
124.29 ± 10.3
|
125 ± 11.09
|
0.804
|
|
DBP (mean ± SD)
|
76.32 ± 11.74
|
75.86 ± 12.01
|
0.884
|
|
Anisocoria (pupil size)
|
|
Absent
|
20 (71.43%)
|
26 (92.86%)
|
0.078
|
|
Present
|
8 (28.57%)
|
2 (7.14%)
|
|
Operative parameters
|
|
Operative time (min) (mean ± SD)
|
263.21 ± 33
|
200.36 ± 39.09
|
<.0001
|
|
Blood loss (mL) (mean ± SD)
|
462.5 ± 126.6
|
410.71 ± 103.06
|
0.109
|
|
Postoperative complications
|
|
No
|
17 (60.71%)
|
15 (53.57%)
|
0.589
|
|
Yes
|
11 (39.29%)
|
13 (46.43%)
|
|
Hospital stay (d) (mean ± SD)
|
13.79 ± 5.37
|
16.21 ± 5.83
|
0.12
|
|
Mortality rate
|
|
No
|
25 (89.29%)
|
27 (96.43%)
|
0.611
|
|
Yes
|
3 (10.71%)
|
1 (3.57%)
|
Abbreviations: DBP, diastolic blood pressure; NWT, nonwatertight; SAH, subarachnoid
hemorrhage; SBP, systolic blood pressure; SD, standard deviation; WT, watertight.
Table 2
Comparison of preoperative and postoperative Glasgow Coma Scale between the WT group
and the NWT group
|
Pre- and postoperative Glasgow Coma Scale
|
WT group (n = 28)
|
NWT group (n = 28)
|
p-Value
|
|
Preoperative
|
|
Moderate (9–12)
|
5 (17.86%)
|
9 (32.14%)
|
0.217[c]
|
|
Severe (3–8)
|
23 (82.14%)
|
19 (67.86%)
|
|
Mean ± SD
|
7.25 ± 2.15
|
7.36 ± 1.97
|
|
Median
|
7 (6–8)
|
7.5 (6–9)
|
0.648[b]
|
|
Range
|
4–12
|
4–11
|
|
Postoperative
|
|
Mean ± SD
|
6.46 ± 1.67
|
7.43 ± 3.07
|
0.473[a]
|
|
Median
|
6.5 (5–7)
|
6 (6–8)
|
|
Range
|
3–10
|
4–15
|
Abbreviations: NWT, nonwatertight; SD, standard deviation; WT, watertight.
a Mann–Whitney test.
b Fisher's exact test.
c Chi-square test.
Postoperative complications were present in 11 out of 28 patients (39.29%) in the
WT group whereas 13 out of 28 patients (46.43%) in the NWT group. Complications included
subgaleal fluid collection in four cases and two cases, CSF leak in two cases and
four cases, meningitis in two cases and one case, wound infection/surgical site infection
in one patient and in three cases, and abscess in one patient and three cases of the
WT and NWT groups, respectively. Two cases were complicated with fever in the WT group
only.
Compared with group WT, NWT had significantly lesser operative time (200.36 ± 39.09
vs. 263.21 ± 33 minutes, p < 0.0001), showing that the morbidity associated with operation was controlled faster
in the NWT group ([Table 1]). Using GCS, both interventions were effective in managing patients of TBI. In the
WT group, 3 (10.71%) patients died and in the NWT group, 1 (3.57%) patient died. Though
the mortality percentage was lesser in the NWT group, statistically it was comparable
(p = 0.611). Despite fast surgery, the hospital stay in the NWT and WT groups were statistically
similar (16.21 ± 5.83 vs. 13.79 ± 5.37 days, p = 0.12) ([Table 1]).
GOS score was determined at 1, 2, and 3 months for determining the outcomes. GOS score
improved significantly in both the groups. In the WT group, GOS from a score of 2
(42.86%) and 3 (46.43%%) at 1 month improved to score of 2 (25%), 3 (57.14%), and
4 (7.14%) at 2 months and to a score of 3 (32.14%) and 4 (57.14%), while in the NWT
group, GOS from a score of 2 (71.43%) and 3 (25%%) at 1 month improved to score of
2 (0%), 3 (78.57%), and 4 (17.86%) at 2 months and to a score of 3 (14.29%) and 4
(82.14%). Statistically, the outcomes were comparable at 1 month (p = 0.105) and 3 months (p = 0.188) ([Table 3]).
Table 3
Comparison of GOS between the WT group and the NWT group
|
GOS
|
WT group (n = 28)
|
NWT group (n = 28)
|
p-Value
|
|
At 1st month
|
|
1 (Dead)
|
3 (10.71%)
|
1 (3.57%)
|
0.105[a]
|
|
2 (Vegetative)
|
12 (42.86%)
|
20 (71.43%)
|
|
3 (Severe disability)
|
13 (46.43%)
|
7 (25%)
|
|
At 2nd month
|
|
1 (Dead)
|
3 (10.71%)
|
1 (3.57%)
|
0.01[a]
|
|
2 (Vegetative)
|
7 (25%)
|
0 (0%)
|
|
3 (Severe disability)
|
16 (57.14%)
|
22 (78.57%)
|
|
4 (Moderate disability)
|
2 (7.14%)
|
5 (17.86%)
|
|
At 3rd month
|
|
1 (Dead)
|
3 (10.71%)
|
1 (3.57%)
|
0.188[a]
|
|
3 (Severe disability)
|
9 (32.14%)
|
4 (14.29%)
|
|
4 (Moderate disability)
|
16 (57.14%)
|
23 (82.14%)
|
Abbreviations: GOS, Glasgow Outcome Scale; NWT, nonwatertight; WT, watertight.
a Fisher's exact test.
Discussion
This study was conducted with an objective to compare the two interventions of DC
with WT dural closure and NWT dural closure for treatment of patients of TBI with
respect to the outcomes and operative characteristics.
In the present study, compared with group WT, NWT had comparable mean age (45.79 ± 20.33
vs. 44.5 ± 16.28, p = 0.795), gender distribution (60.71% vs. 67.86% males, p = 0.577), comorbidities (diabetes: 17.86% vs. 14.29%; hypertension: 17.86% vs. 17.86%,
p = 1), vitals (pulse rate: 97.11 ± 13.06 vs. 95.32 ± 12.82, p = 0.608; SBP: 125 ± 11.09 vs. 124.29 ± 10.3, p = 0.804; DBP: 75.86 ± 12.01 vs. 76.32 ± 11.74, p = 0.884), and anisocoria (7.14% vs. 28.57%, p = 0.078). In comparison, Vieira et al[15] conducted a study including 57 patients, who underwent unilateral DC where the patients
were categorized into: those with WT duraplasty (WT, n = 29) and without WT duraplasty (NWT, n = 27). The results showed that the mean age of the patients was 33.4 years, with
no significant difference in age between the NWT and WT groups (p > 0.05). Compared with WT, NWT also had similar anisocoria (44.5% vs. 25%, p = 0.130).
In the present study, compared with group WT, NWT had significantly lesser operative
time (200.36 ± 39.09 vs. 263.21 ± 33 minutes, p < 0.0001), showing that the morbidity associated with the operation was controlled
faster in the NWT group. Similar to the present study results, NWT dural closure is
reported to take lesser operative time than WT closure technique in previous studies
also. Vieira et al[15] reported that compared with WT, NWT had significant lesser time of surgery (101
vs. 132 minutes, p = 0.001). Similar to this, Barth et al[16] reported that in the NWT dural closure group, surgeries were faster as closure time
was significantly lesser in the NWT group than the primary and secondary WT groups
(5.3 vs. 13.1 vs. 14.6 minutes, p < 0.05). It must be stressed here that NWT holds superiority to WT in this aspect
since such a time reduction may decrease morbidity associated with longer surgeries,
which are often associated with greater blood loss and this may ultimately lead to
better neurosurgical outcomes.[15]
Concurrent with this notion of lesser morbidity with respect to lesser time of surgery,
in the present study compared with group WT, NWT had lesser blood loss (410.71 ± 103.06
vs. 462.5 ± 126.66 mL) but statistically it was not significantly different (p = 0.109). To the best of our knowledge, none of the similar previous studies evaluated
the amount of blood loss between WT and NWT dural closure.
It was observed that preoperatively, both groups had comparable GCS, with a mean value
of 7.25 ± 2.15 in the WT group and 7.36 ± 1.97 in the NWT group (p = 0.648). Postoperatively also, both groups showed comparable GCS (WT group vs. NWT
group: 6.46 ± 1.67 vs. 7.43 ± 3.07, p = 0.473). This showed that both interventions were effective in managing patients
of TBI. This was supported by the findings of Vieira et al,[15] who reported that compared with WT, NWT had similar postoperative GCS scores (GCS
score 3–8: 48.1% vs. 50%; GCS score 3–8: 51.9% vs. 42.9%; 14–15: 0% vs. 7.1%; p = 0.524).
In the present study, complications were present in 39.29% (n = 11) patients in the WT group and in 46.43% (n = 11) patients in the NWT group ([Fig. 2]); but statistically, it was found that complication rate was comparable among the
two groups (p = 0.589). The common complications were subgaleal fluid collection and CSF leak in
group WT and CSF leak and wound infections in the NWT group. In corroboration with
the present study, Vieira et al[15] reported that compared with WT, NWT had comparable complications (14.8% vs. 17.9%,
p = 1). CSF leak developed in two patients in each group, wound infection in one patient
in each group, and subgaleal fluid collection developed in two patients in the control
group and one patient in the test group. It was concluded that no increased risk of
CSF leaks exists once the arachnoid is intact. Additionally, attempts to achieve WT
closure may cause small defects on suture lines, creating a “one-way valve” effect
that may increase CSF leakage development. Cho et al[17] analyzed the occurrence of CSF leakage after NWT closure. Comparable rate of CSF
leakage between NWT closure and WT closure was seen in supratentorial approach. In
infratentorial approach, higher rate of CSF leakage was seen in NWT closure than that
in WT closure.
Fig. 2 Comparison of various postoperative complications between the watertight (WT) group
and the nonwatertight (NWT) group.
Similar to the present study, Abouelmaaty and Molla[18] found that compared with the WT group, the NWT group had similar subcutaneous CSF
collection (8% vs. 4%), delayed wound healing (8% vs. 4%), meningitis (4% vs. 0%),
and CSF leak (4% vs. 4%) (p > 0.05). Thus, NWT dural closure was suggested to be safe option to WT dural closure
in patients who undergo supratentorial craniotomies; however, it was not considered
to be superior to WT. Wang et al[19] in their study explained the higher rate of infection was by the fact that in patients
who undergo NWT dural closure, circulation of CSF occurs between the epidural and
subdural space and contacts the skull, galea, muscle, and scalp. The probability of
infection is raised due to this process.
In the present study, in the WT group 3 (10.71%) patients died and in the NWT group
1 (3.57%) patient died. Though the mortality percentage was lesser in the NWT group,
statistically it was comparable (p = 0.611). This was in line with the findings by Vieira et al,[15] who reported that compared with WT, NWT had comparable mortality rate (37% vs. 25%,
p = 0.334).
Despite fast surgery, the hospital stay in the NWT and WT groups was statistically
similar (16.21 ± 5.83 vs. 13.79 ± 5.37 days, p = 0.12), which might be because of comparable rate of postoperative complications
and management. Moreover, the hospital stay also gets affected by the mortality of
the serious patients. None of the similar previous studies evaluated hospital stay
between WT and NWT dural closure.
In the present study, GOS score was determined at 1, 2, and 3 months for determining
the outcomes. GOS score improved significantly in both the groups. In the WT group,
GOS from a score of 2 (42.86%) and 3 (46.43%%) at 1 month improved to score of 2 (25%),
3 (57.14%), and 4 (7.14%) at 2 months and to a score of 3 (32.14%) and 4 (57.14%);
while in the NWT group, GOS from a score of 2 (71.43%) and 3 (25%%) at 1 month improved
to score of 2 (0%), 3 (78.57%), and 4 (17.86%) at 2 months and to a score of 3 (14.29%)
and 4 (82.14%). Statistically, the outcomes were comparable at 1 month (p = 0.105) and 3 months (p = 0.188). The findings were in line with the study of Vieira et al,[15] who reported that compared with WT, NWT had comparable GOS scores (GOS score 1:
37% vs. 25%; 2: 18.5% vs. 10.7%; 3: 25.9% vs. 25%; 4: 1% vs. 14.3%; 5: 7.4% vs. 25%;
p = 0.428). This shows that overall, both interventions fair equally well with respect
to the outcomes of the patients with the only difference being in the operative time.
Limitations
The present study did not compare the cost-effectiveness of WT and NWT dural closure
in TBI patients. The patient care guidelines for elective cranial surgery differ from
one institution to the next. As a result, the study results that were determined through
the analysis might not be applicable to other institutions.
Conclusion
This study indicates that the NWT group had significantly lesser operative time as
compared with the WT group. However, amount of blood loss, hospital stay, complications,
and mortality were similar among the two groups. Even the follow-up outcome response
was comparable among the two groups. It can be concluded that although not significantly
superior to WT dural closure in supratentorial craniotomies, adaptive NWT dural closure
may be a good, safe, and time-saving alternative to it.
