A randomized controlled trial on effects of different hemostatic sponges in posterior spinal fusion surgeries
Xu et al. BMC Surgery
A randomized controlled trial on effects of different hemostatic sponges in posterior spinal fusion surgeries
Derong Xu 0
Zhinan Ren 0
Xin Chen 0
Qianyu Zhuang 0
Lin Sheng 0
Shugang Li 0
0 Department of Orthorpaedic Surgery, Peking Union Medical College Hospital , No.1 Shuai Fu Yuan, Wang Fu Jing Street, Beijing 100730 , People's Republic of China
Background: Spinal fusion surgery is associated with significant blood loss, which may result in potential clinical complications, it is necessary to take safe and effective measures to reduce blood loss in surgery. We perform this study to assess the impact of three different hemostatic materials on perioperative blood loss. Methods: We performed a Randomized Controlled Trial research and recruited patients with lumbar disease into the study between November 2013 and March 2015. All the participants were randomly assigned to 3 groups using a simple equal probability randomization scheme: Group A (Stypro hemostatic sponge), Group B (Collagen hemostatic sponge) and Group C (gelatin sponge). We compared postoperative blood loss between these 3 groups. Results: In our study, drainage volume in the first 24 h of patients in Group A and B is significantly smaller, as well as total postoperative volumes of drainage (p < 0.05) during their hospital stay. The drainage volumes in the second 24 h were similar in the 3 groups. We also found that the average drainage Hematocrit (HCT) reduced over time, the average HCT of drainage is 18.04% and 11.72% on the first day and on the second day respectively. Conclusions: Hemostatic collagen sponge demonstrated better hemostasis effects than gelatin sponge with lower volume of postoperative drainage volume and blood loss in posterior spinal fusion surgery. Trial registration: The trial registration number (TRN) of the study is ISRCTN29254316 and date of registration is 25/10/2016. Our trial was registered retrospectively.
Lumbar fusion surgery; Hemostatic collagen sponge; Gelatin sponge; Blood loss
Spinal fusion surgeries may result in significant blood
loss, which is often associated with cardiovascular
complications and high rates of allogeneic blood
transfusion . Therefore, it is imperative to take safe and
effective measures to reduce blood loss and rates of
transfusions after spinal fusion surgeries. In recent years,
the use of hemostatic materials, such as gelatin sponge
and other collagen sponges, has led to significant
reductions in both intraoperative blood loss and postoperative
transfusions . However, there are many differences
between gelatin sponges, which have been in use for
several decades, and collagen sponges which have been
featured with new properties. The objective of our study
was to assess the impact of three different hemostatic
materials on operative blood loss.
Our study is a randomized controlled trial. The Stypro
hemostatic sponge used in this study mainly consisted of
medicinal protein collected from pigs. The Collagen
hemostatic sponge is also a product derived from animal
original type I collagen from cows. Both of them possess
such biological properties that can activate the intrinsic
coagulation pathway. The gelatin sponges, which have
no bioactivity, control bleeding mainly by volume
expansion and mechanical compression.
This RCT study was carried out at PUMC Hospital.
We recruited patients with lumbar diseases into the study
from November, 2013 to March, 2015. The inclusion
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Fig. 1 CONSORT flow diagram
criteria were lumbar stenosis, disc disease, and instability
(e.g. grade I-II spondylolisthesis, spondylolisthesis
/spondylolysis) which were indicated for spinal surgeries. The
exclusion criteria were as follows: 1. severe medical
comorbidities such as osteoporosis, anemia and
cardiovascular disease. 2. Involvement of more than three surgical
levels 3. Patients had abnormal prothrombin time (PT),
partial thromboplastin time (PTT) and International
Normalized Ratio (INR) 4. Patients were taking
antiplatelet aggregates such as Aspirin or other anticoagulants.
All the participants were randomly assigned to 3 groups
using a simple equal probability randomization scheme:
Group A (Stypro hemostatic sponge group), Group B
(Collagen hemostatic sponge group) and Group C (gelatin
sponge group). The participants were presented in a flow
diagram in Fig. 1.
All the patients were performed posterior lumbar
decompression, internal fixation and bone graft fusion
surgery by the same surgeon. In addition, patients
Table 1 Demographic date
Preoperative HGB (g/L)
Mean duration of
hospital stay (days)
underwent discectomy if diagnosed with disc herniation
and reduction if accompanied with spondyloliosthesis.
After the decompression, we controlled the bleeding
meticulously with use of bipolar electrocautery, after which
we placed different sponges on the surface of spinal dura
mater respectively. We applied hemostatic sponges with
two different brands in group A (Stypro hemostatic sponge)
and group B (Collagen hemostatic sponge), as for group C,
we used gelatin sponges. According to the size of exposed
spinal dura, we cut the hemostatic materials into proper
corner to ensure that the entire dura would be covered.
Intraoperative estimated blood loss (EBL) were calculated
on the basis of surgical sponges soaked and volume in
suction canisters, subtracting irrigation fluid added to
the surgical field . Deep drainage was placed below
the fascia in all patients at the end of operations. We
recorded the amount of postoperative drainage in the
first 24 h, the second 24 h and the total drainage
volume. In addition, complete blood count (CBC) was
examined and analyzed for every drainage sample to
obtain data of HCT and Hemoglobin (HGB), which
were used to calculate the blood contained in drainage.
The drainage was routinely removed when the drain
output per 24 h was <50 ml. Clinical data, including age,
height, weight, body mass index (BMI), operative durations,
surgical levels, intraoperative blood loss, related
complications, and length of hospital stay were compared between
the three groups. Besides, three parameters were compared
between 3 groups: (1) volume of drainage in the first and
second 24 h, and patient’s total drain output (2) HCT of
drainage in the first and second 24 h (3) drainage blood at
different time points.
This prospective study was approved by the ethical
committee at Peking Union Medical College Hospital,
and all participants provided written informed consents
for the study and surgery.
Table 2 The information of postoperative drainage
Volume of Drainage in
the second 24 h (ml)
Total volume of drainage (ml)* 231.5 ± 18.1 248.5 ± 18.8 318.5 ± 26.7
*Data between 3 groups has siginificant difference
The difference in demographic and perioperative data
between 3 groups was analyzed using the One-Way
ANOVA. In all analyses, the level of statistical significance
was set at P < 0.05. All data analyses were performed with
the SPSS 19.0 software package.
In this study, 92 patients who met the inclusion criteria
were enrolled. Among these patients, 30 patients were
assigned to group A, 30 patients were assigned to group
B and 32 patients were assigned to group C. No
significant difference in age, height, weight, BMI, surgical level,
intraoperative blood loss, operative durations, the mean
length of hospital stay and coagulation indices were
identified between the 3 groups, as presented in Table 1.
The detailed information of drainage at various time
points is presented in Table 2 and Fig. 2. Compared with
patients in Group C, patients in Group A and B
exhibited significantly smaller drainage volume in the first
24 h, as well as total postoperative volumes of drainage
(p < 0.05) during their hospital stay. The drainage volumes
in the second 24 h were similar in the 3 groups and
exhibited no significant differences.
The HCT data of each drainage sample are presented
in Table 3, from which we learned that on the first day,
the average HCT of drainage is 18.04%, which is lower
than that in whole blood CBC by a small extent. However,
the average drainage HCT reduced over time. On the
second day, when the drainage was removed, the average HCT
dropped to 11.72%.We also found that the HCT of
drainage at different stage were similar for patients in 3 groups.
There were no perioperative complications, such as deep
venous thrombosis (DVT)/pulmonary embolism (PE),
postoperative hematomas/seromas, and postoperative
infections, in the 3 groups.
Patients undergoing spinal fusion surgeries are at risk
of large amounts of blood losses, which may result in
potential risks for subsequent postoperative hemodynamic
instability, blood transfusions, and delayed recovery. Rapid
and effective hemostasis during the operation allows the
surgeon to retain visualization of the surgical sites, thus
minimizing the potential injuries to nerve roots and
reducing procedure durations. At the same time, effective
intraoperative hemostasis plays a major role in reducing
morbidity, mortality, and health care costs . Yu-Hua
Huang reported that substantial bleeding in lumbar fusion
is associated with higher incidences of morbidities and
prolonged length of hospital stay .
Hemostatic sponges and gelatin sponges are hemostatic
material currently offered as prophylactic agents to reduce
surgery-associated blood loss. Gelatin sponge is highly
absorptive, expansile, and works through mechanical
hemostatic mechanism . Jian Wu reported that
application of absorbable gelatin sponge at the end of
multilevel posterior lumbar fusion can significantly
decrease postoperative drain outputs and length of
hospital stays . Samuel K. Cho, on that basis, added
the known coagulation factor II, thrombin, into gelatin
to endow it with both mechanical and chemical hemostatic
properties . Their results showed that the
thrombinsoaked gelatin sponges would further reduce postoperative
bleeding and subsequent drain output . However, the
preparation of thrombin-soaked gelatin sponge is complex
and time-consuming, which may increase operative
durations and anaesthetic risks . The hemostatic sponge has
characteristics of both thrombin and gelatin at the same
time, so it is widely used in various kinds of surgeries.
However, there remains no consensus regarding its efficacy in
lumbar spinal surgeries.
Fig. 2 Comparison of postoperative drainage
HCT of Drainage in the
second 24 h (%)
Drainage blood in the
second 24 h (ml)
Table 3 The Drainage blood of postoperative drainage
HCT of Drainage in 24 h (%)
18.04 ± 1.22 20.85 ± 1.16 21.06 ± 1.17
Drainage blood in 24 h (ml)* 34.95 ± 5.05 39.37 ± 3.79 54.06 ± 5.56
11.72 ± 1.17 13.22 ± 1.23 12.53 ± 1.24
39.62 ± 5.13 47.53 ± 6.08 61.84 ± 6.60
*Data between 3 groups has siginificant difference
In our study, those received hemostatic collagen
sponges exhibited lower postoperative drainage than
those received gelatin sponges in the first 24 h. However,
volume of drainage in the second 24 h was similar
between the 3 groups. We inferred that on the second day,
the postoperative bleeding is less and the effects of three
hemostasis materials were not lastingly significant.
Previous studies referred the drainage volume as a main
measurable index of postoperative blood loss. However,
the transfusion for blood loss after surgery depends not
only on the fluid loss amount but also on the pure blood
contain in drainage. We believe that postoperative
drainage volume does not necessarily equal to postoperative
blood loss because the composition of drainage varies
from person to person and also with time-lapse after
operations . These differences can be reflected through
some parameters, such as HCT and HGB of drainage.
According to our investigation, HCT of postoperative
drainage in 24 h always fluctuates in a certain range
between 15% to 25%, with HGB reaching a maximum of
80 g/L. However, after 24 h, the HCT and HGB of
drainage declined apparently, sometimes HGB was less than
10 g/L. These results demonstrated that the blood
Fig. 3 Comparison of postoperative drainage blood
contained in drainage decreases while other
components, such as tissue fluid, becomes the major
The primary function of hemostatic collagen sponge is
bleeding control, therefore, applying a precise parameter
to calculate the real volume of blood loss in drainage is
necessary. We examined CBC test for drainages and
recorded the HCT and HGB of the fluid. Then we calculated
the drainage blood to estimate patients’ postoperative
blood loss. The calculation formula is: drainage blood =
volume of drainage × HCT . We compared
postoperative drainage blood of 3 groups in Fig. 3.
As a result, we did not find statistically significant
differences of drainage HCT and HGB between the
three groups. As for blood in drainage, group A and
group B appeared less than group C because of different
drainage amount, but no differences were found between
group A and group B. These results suggested that the
hemostatic collagen sponge can reduce operative bleeding
without influencing blood contained in drainage.
Our study suggests that hemostatic collagen sponge
demonstrated better hemostasis effects than gelatin sponge
with lower volume of postoperative drainage volume and
blood loss in posterior spinal fusion surgery. These findings
are important to note as surgeons are under increasing
pressure to minimize costs and streamline the entire
surgical experience for spinal fusion surgery. We believe
that hemostatic collagen sponge is an effective tool in
reducing the surgical bleeding and its associated risks.
However, careful surgical technique always remains
crucial to the success of surgery, which cannot be
replaced by sole use of hemostatic material.
BMI: Body mass index; CBC: Complete blood count; EBL: Intraoperative
estimated blood loss; HCT: Hematocrit; HGB: Hemoglobin
There are no special acknowledgements in our study.
Availability of data and materials
The dataset supporting the conclusions of this article is included within the
additional file, which is an excel named “STK KJB data”.
In our study, SL and DX participated in the design of the study, ZR and XC
performed the statistical analysis. DX and QZ drafted of the manuscript, LS
helped to draft the manuscript. All authors read and approved the final
Ethics approval and consent to participate
This prospective study was approved by the ethical committee at PUMC
Hospital, the reference number is KS2014057, and all participants provided
written informed consents for the study and surgery.
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