In the description of our study design, we follow the Consolidated Standards of Reporting
Trials (CONSORT statement).
This was a randomized unblinded prospective study, which was reviewed and approved
by the Medical Ethics Committee of Wangjing Hospital of the China Academy of Chinese
Medical Sciences(WJEC-KT-2017-013-P002), and was preregistered in the Chinese Clinical Trial Registry (ChiCTR1800015825). Confidentiality was maintained with all patient records.
Currently, the negative pressure drainage is controversial and there is no literature
report of compression therapy on the postoperative course of posterior lumbar decompression
and internal fixation. Therefore, we proposed to recruit 60 patients to investigate
the effect of compression therapy on the postoperative course of posterior lumbar
decompression and internal fixation, these patients will randomly assigned into two
groups with an equal number.
From May 2018 to January 2019, a total of 76 patients with lumbar spinal stenosis
with documented evidence of symptomatic lumber spinal stenosis confirmed by clinical, computed tomography, and magnetic resonance
imaging (MRI) findings were performed posterior lumbar decompression and internal
fixation by the first author. Among them, 60 patients were recruited into the study，all
these patients provided written informed consent for the public use of their treatment
data and related pictures. Inclusion and exclusion criteria are listed in Table 1.
Patients younger than 40 years or with other risk factors[8,19,20] were excluded.
Only patients aged older than 40 years, with typical clinical symptoms of lumbar spinal
stenosis, and radiological confirmation were included in the study.
Patients were assigned to the treatment group (closed suction drain(CSD) with compression therapy) or to the control group (CSD alone) by a random number generator before the trial started. The same standard surgical
technique was performed on all patients.
In the treatment group (CSD with compression therapy), a 16 Fr silicone CSD ( Fr-16; Shandong Branden Medical Devices Co., Ltd., Shandong City, China) was inserted
into the surgical area. All CSDs were used with mild suction pressure (half negative). For compression therapy after the operation, a sterile gauze bandage was used and the aseptic dressing was folded into a shuttle shape (Fig. 1), which was preferably
thick to counteract the lumbar lordosis. At the same time, an elastic waist band (PCS-5011; Rehan Health Care Co., Ltd., Shanghai City, China)
was applied for pressure. Before operation, we laid the cuff of the cuff sphygmomanometer in the middle of
the patients’ waist in prone position, tightened the inflatable valve when the mercury
column was about to rise, pressed it with elastic waist band, and marked it when the
pressure reached 20 mmHg and 40 mmHg, respectively(Fig. 2,3). The elastic waist band was worn as far as possible to the
40 mmHg marking lines after the operation, if the patients complain problems with breathing or abdominal
discomfort, the elastic waist band was loosed according to the patient’s preference,
but cannot exceed the 20mmHg marking line (Fig. 4). If relaxing the elastic waist band to 20mmHg still does not relieve the symptoms,
remove the elastic waist band and this patient drop out of the study. The elastic
waist band was worn until the wound healed after the operation. In the control group, CSD alone was administered in the same manner as described for
the treatment group.
The patients’ back pain was assessed with the visual analogue scale (VAS). The most
painful back wound VAS score after the operation was recorded. The patients’ drainage volume (postoperatively, the CSD was removed when the amount
of bleeding did not exceed 100 mL per day, and the total drainage volume was recorded),
white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (Hb) levels,
erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels  on the 1st, 3rd, and 10th days after the operation were recorded. These indicators
were compared between the two groups to evaluate the effects of compression therapy
for postoperative posterior lumbar decompression and internal fixation. All of the
60 patients were available for follow-up, and postoperative complications were recorded
at follow-up. The mean duration of follow-up was 6.25±2.36 months.
Statistical analysis was performed using SPSS 22.0 software (IBM Corp., Armonk, NY,
USA). Measurement data are presented as the mean (standard deviation). The Kolmogorov–Smirnov
test and histograms indicated a non-parametric distribution of the data. Significance
of differences of outcome measures between the two groups was analyzed using the independent
sample test or Mann–Whitney U test (p<0.05) depending on normal distribution. Numeration
data between the two groups were compared using the chi-square test.