Keywords
anxiety - depression - estenosis - minimally invasive surgical procedures - spine
Introduction
The main reason for surgery on the spine is lumbar neural compression, which promotes
the sensation of paresthesia, pain, loss of sensitivity, and strength in the lower
limbs.[1] The most common reasons for lumbar neural compression are spinal canal stenosis
and herniated discs. In the failure of conservative treatment or the presence of motor
neurological damage, operative treatment should be indicated, with the gold standard
being neural decompression. The procedure can be performed openly or microsurgically,
with tubular retractors or endoscopy.[2]
[3] Minimally invasive lumbar decompression is a relatively new technique that represents
an alternative to open decompression.[4] The minimally invasive technique demonstrates similar effectiveness to open laminectomy
but with lower blood loss, shorter hospital stays, and lower incidence of reoperation.[5]
[6]
Previous studies have shown an association between symptoms of anxiety, depression,
and chronic low back pain.[7] However, the relationship between anxiety symptoms and surgical outcomes in individuals
with radiculopathy is not well-established in the literature. Thus, the present study
investigates the association between surgical outcomes and the presence of preoperative
anxiety symptoms, in addition to the effects of surgery on patients' mental health
over time.
The objectives were: Primary - to evaluate the association between anxiety symptoms
and clinical and functional outcomes of patients undergoing minimally invasive lumbar
decompression. Secondary - compare anxiety symptoms before and after minimally invasive
lumbar decompression surgery.
Methodology
This is a prospective cohort study with 44 patients, with follow-up for 6 months after
surgery between January 2020 and July 2022. All procedures were performed at the Hospital
Israelita Albert Einstein, a private quaternary hospital, a reference in spine surgery,
located in the city of São Paulo. The study was approved by the institution's Ethics
Committee (CAAE: 94868618.7.0000.0071).
Inclusion criteria: Individuals who had symptoms of lumbar neural compression, radiculopathy or neurogenic
lameness, single-level lumbar neural compression, with failure of conservative treatment
for at least 6 weeks (or less, in the presence of acute motor damage with a motor
force of less than or equal to 3), underwent single-level minimally invasive lumbar
decompression.
Exclusion criteria: Open surgeries, placement of implants in the spine, reoperations, complications,
or the absence of response to questionnaires after 6 months of surgery.
The collected data was sent and stored in the REDCap software (Vanderbilt University,
Nashville, TN, USA[8]
[9]), at the time before and 6 months after surgery. The preoperative questionnaires
were collected shortly after the informed consent form (ICF) was completed.
Operative Technique
The patients were positioned in the genupectoral position without needing bladder
probing. The fluoroscopic image in profile incidence confirmed the anatomical level,
with the needle positioned at the height of the intervertebral disc. After placing
sterile drapes, a paramedian incision was made, located 1 cm lateral to the midline
and 14 mm long, corresponding to the size of the tubular retractor used. After opening
the fascia, the musculature was progressively dilated with sequential cannulas until
the placement of the 14-mm-diameter closed tube. The tube length varied according
to each patient, between 50 and 90 mm deep. The tube was attached to the operating
table using a mechanical arm, and from that moment on, the surgery was performed using
microscopy (Pentero microscope, Zeiss, Germany). Neural decompression was performed
according to the needs of each case. It may include microdiscectomy for cases of a
herniated disc, foraminotomy for foraminal stenosis, decompression of lateral recess
stenosis, or over-the-top decompression for central stenosis. After that, the wound was closed with continuous intradermal
suture and simple dressing. Drains were not inserted. Ambulation was authorized on
the same day of surgery, and discharge occurred the day after surgery. The surgeries
were performed by a senior physician who specialized in minimally invasive spine surgery.
Collected Outcomes
Visual Analog Pain Scale
(VAS):[10] The visual pain scale describes the intensity of the patient's leg and back pain-related
pain. The score can range from 0 (non-existent pain) to 10 (pain with extreme intensity)
Global Perceived Effect of Change
(GPE) (self-perceived improvement)[11]: Scale designed to quantify patient improvement or deterioration over time, usually
to determine the effect of an intervention or to chart the clinical course of a condition.
Hospital Anxiety and Depression Scale
(HADS):[12] The questionnaire consists of 14 questions. Each of its items can be scored from
0 to 3, composing a maximum score of 21 points for each scale.
Oswestry Disability Index
(ODI) Version 2.0:[13] This version was adapted for Brazil to measure functional disability in individuals
with low back pain. It has 10 scales of 6 points each. The total ODI score ranges
from 0 (no disability) to 100 (maximum disability).
Categorization of patients with and without anxiety symptoms
Patients were stratified into two groups depending on the score at the presurgical
moment of anxiety (HADS). The chosen cutoff point (≥ 9) in the anxiety score was based
on the description of Zigmond and Snaith[14] on the interpretation of results.
-
Group 1: non-anxious patients. Hospital Anxiety and Depresseion Scale subscale anxiety collected presurgically < 9
points
-
Group 2: anxious patients. Hospital Anxiety and Depression Scale subscale anxiety collected presurgically ≥
9 points
Statistical analysis
To evaluate the different associations between the groups, the variations of scores
(depression HADS, VAS, GPE) and final scores in the groups were calculated separately.
The data were submitted to Shapiro-Wilk normality tests. Subsequently, non-parametric
statistical tests were applied to measure the difference in postoperative outcomes
between patients' “cases” versus “non-cases” of anxiety. Categorical variables were
followed by the percentage that each category occupies and continuous variables by
the standard deviation. Nonparametric statistical tests were performed to compare
the initial and postoperative scores. The statistical tests applied for continuous
variables were Mann-Whitney and, for categorical variables, the Pearson chi-square
test. Subsequently, an analysis was performed comparing the evolution of anxious patients
with that of non-anxious patients. This comparison was made by evaluating the variation
of scores (final score–initial score) and comparing them between the groups.
Results
The sample consisted of 44 patients, 22 males and 22 females, with a mean age of 42.5
years (20–70 years). The mean body mass index (BMI) of the sample was 27.1 kg/m2. Most of the patients have completed higher education. [Table 1] presents the patients' demographic data stratified in relation to the HADS score
at the preoperative time, with 20 patients in the non-anxious group and 24 patients
in the anxious group. Demographic data, such as BMI, age, height, weight, education,
and sex, are similar between groups.
Table 1
|
|
Group
|
|
All
|
Non-anxious
|
Anxious
|
|
(n = 44)
|
(n = 20)
|
(n = 24)
|
|
Gender
|
|
|
|
|
Male (%)
|
22
|
12
|
10
|
|
Female (%)
|
22
|
8
|
14
|
|
Schooling
|
|
|
|
|
Undergraduate degree
|
33
|
17
|
16
|
|
Unfinished undergraduate degree
|
4
|
0
|
4
|
|
High school degree
|
5
|
2
|
3
|
|
Middle school degree
|
1
|
0
|
1
|
|
Technical degree
|
1
|
1
|
0
|
|
Age
|
42.5 ± 10.4
|
45.6 ± 10.4
|
39.9 ± 9.76
|
|
BMI (Kg/m2)
|
27.1 ± 3.8
|
26.8 ± 3.52
|
27.3 ± 4.09
|
|
Height (m)
|
1.7 ± 0.1
|
1.71 ± 9.13
|
1.71 ± 12.1
|
|
Weight (Kg)
|
79.4 ± 14.4
|
79.3 ± 16
|
79.6 ± 13.2
|
In the comparison between preoperative clinical scores and those 6 months after the
procedure, improvement was observed in all scores (p < 0.05), regardless of the group. Clinical improvement was observed by the increase
in self-perceived improvement (GPE), reduction in leg and back pain scores, and HADS
scores for both subscales (depression and anxiety), according to [Table 2].
Table 2
|
|
Preoperative
|
|
|
|
6 months after surgery
|
|
|
|
Score variation 6 months
|
|
|
Non-anxious
|
|
Anxious
|
p
|
Non-anxious
|
|
Anxious
|
p
|
Non-anxious
|
|
Anxious
|
|
HADS
|
|
|
|
|
|
|
|
|
|
|
|
|
Anxiety
|
5.65 ± 2.06
|
|
11.3 ± 2.07
|
<0.001*
|
3.9 (±3.42)
|
|
7.29 (± 3.66)
|
0.003
|
-1.75 (±3.61)
|
|
-3.96 (±3.84)
|
|
Depression
|
4.7 ± 2.13
|
|
8.83 ± 3.41
|
<0.001*
|
4.1 (±1.83)
|
|
6.67 (±3.29)
|
0.003
|
-0.6 (±2.76)
|
|
-2.17 (±3.06)
|
|
VAS
|
|
|
|
|
|
|
|
|
|
|
|
|
Back
|
4.6 ± 3.22
|
|
5.92 ± 2.7
|
0.16
|
2.45 (±3.22)
|
|
2.58 (±2.41)
|
0.562
|
-2.15 (±3.9)
|
|
-3.33 (±3.41)
|
|
Legs
|
6.6 ± 2.89
|
|
7.72 ± 2.4
|
0.44
|
1.8 (±2.78)
|
|
1.62 (±2.24)
|
0.919
|
-4.8 (±4.21)
|
|
-6.08 (±2.73)
|
|
GPE
|
-0.6 ± 3.55
|
|
-0.38 ± 3.51
|
0.73
|
2.6 (±2.89)
|
|
2.33 (±2.56)
|
0.457
|
3.2 (±5.4)
|
|
2.71 (±4.36)
|
|
ODI
|
36.5 ± 20.8
|
|
52.8 ± 22.9
|
0.02*
|
10.4 (±10.4)
|
|
13.8 (±10.9)
|
0.29
|
-26.1 (±21.4)
|
|
-37.9 (±21.9)
|
Six months after surgery, anxious patients maintained statistically worse mental health
scores compared to non-anxious patients. However, the score reduction in the 6 months
was higher in anxious patients. That is, anxious patients maintained lower mental
health scores after surgery compared to non-anxious patients but obtained a more significant
reduction in points (-3.96 vs -1.75); this pattern is repeated in depression scores.
Another finding was the different variations of the ODI score between the groups.
While the anxious group had a drop of 37.9 points, on average, the non-anxious group
had a reduction of 26.1 points. In this sense, the anxious group had a 74% reduction
in the average ODI score, and the non-anxious group had 71.5%.
The other scores showed similar variation between the groups. Except for the GPE score,
all scores showed more significant variation between preoperative and postoperative
moments in the anxious group. Regarding the back VAS score, there was a reduction
of 47% in not anxious and 56% in anxious patients. The leg VAS, in turn, had a reduction
of 79% in anxious and 72.8% in non-anxious patients.
[Table 3] presents the evolution of patients without considering the classification of anxiety
and depression, showing significant variation in mental health indicators. After 6
months of the procedure, there was a reduction in the HADS scores in both anxiety
and depression subscales and in the other scores. The GPE and ODI scores increased
in the sample, respectively, demonstrating increased self-perception of improvement
and functionality.
Table 3
|
Preoperative
|
6 months after surgery
|
|
|
|
|
|
|
p
|
|
HADS
|
|
|
|
|
|
|
Anxiety
|
8.7 (±3.48)
|
5.91 (±4.01)
|
< 0.001
|
|
Depression
|
6.95 (±3.54)
|
5.6 (±3.03)
|
0.005
|
|
VAS
|
|
|
|
|
|
|
Back
|
5.32 (±3.03)
|
2.52 (±2.70)
|
< 0.001
|
|
Legs
|
7.2 (±2.66)
|
1.70 (±2.47)
|
< 0.001
|
|
GPE
|
-0.48 (±3.48)
|
2.45 (±2.69)
|
< 0.001
|
|
ODI
|
45.4 (±23.2)
|
12.2 (±10.70)
|
< 0.001
|
A positive correlation was observed between preoperative ODI (p < 0.001) and preoperative anxiety ([Fig. 1A]); that is, patients with higher anxiety scores reported greater dysfunction function
at the preoperative time. In addition, a negative correlation was observed between
preoperative anxiety and ODI score variation, that is, patients with initially higher
anxiety scores reported greater functional gain after surgery.
Fig. 1 Anxiety scatter plot x ODI. Spearman rank coefficient.
Discussion
Spine surgeries have evolved in recent years, and techniques considered less invasive
become increasingly used.[15] In the present study, microtubular and endoscopic surgery was used, which proposes
little tissue aggression and an early return to normal preoperative activities.[16] This approach promoted pain improvement, self-perceived improvement, anxiety, and
depression symptoms 6 months after surgery.
The age of the patients in this study corresponds to that reported in other studies,
with the mean age of patients with neural compression being 35 to 55 years.[17]
Previous studies correlate chronic low back pain with worsening mental health.[18]
[19] However, the impact of anxiety symptoms on the clinical and functional outcomes
of patients with neural compression undergoing minimally invasive lumbar decompression
is not well established in the literature. Specific studies on the subject suggest
that anxiety symptoms do not modify the prognosis of patients.[20] However, the initial hypothesis of the present study was that anxious patients would
have worse clinical and functional outcomes. Contrary to the initial hypothesis, and
in agreement with previous studies, it was observed that more anxious patients had
similar clinical outcomes to those of non-anxious patients. However, studies on the
effects of anxiety on clinical outcomes should continue since it is a comorbidity,
and these, in turn, are obstacles in the postoperative treatment of patients.
Regarding the modulation of the anxiety score in patients after surgical treatment,
the data obtained suggest that, in individuals adequately selected for neural compression
surgery, anxiety symptoms would be caused by pain, not originate it. Six months after
surgery, a significant reduction in anxiety symptoms was observed, accompanied by
an improvement in pain and quality of life scores.
The mean variation of the functionality scale during the 6 months was significant
(33.2 points), similar to the variation of surgical decompression described in the
systematic review by Ma et al.[21] (28.1–34.5).
Concerning the association tables analyzed, the association between dysfunction and
preoperative anxiety follows that analyzed in previous studies, which suggests worse
anxiety symptoms in patients with more intense lumbar compression symptoms. Simultaneously,
the positive correlation between functional gain and preoperative anxiety demonstrates
that patients with more anxiety symptoms had more significant benefits from surgery
in terms of functionality.
The main limitations of this study are its small sample size, its limitation to a
private hospital center, and its potential inability to represent the reality of other
services. The use of the HADS questionnaire for anxiety screening can be considered
limited due to the lack of face-to-face evaluation by a psychologist. Due to the absence
of evaluation of psychiatric comorbidities in patients and their medication use, it
was not possible to evaluate possible effects between psychiatric comorbidities, medication
use, and the development of anxiety symptoms in patients after surgery. However, the
consistency of the data suggests that the presence of neuropathic pain and dysfunction
in individuals with lumbar neurological compression promoted the appearance of anxiety
symptoms. The factors that corroborate this hypothesis are the initial correlation
between dysfunction and anxiety, followed by a decrease in both due to the therapeutic
effect of surgery on dysfunction, consequently reducing anxiety.
Conclusions
Minimally invasive lumbar decompression surgery promoted clinical and functional improvement,
not being affected by preoperative anxiety symptoms. These, in turn, improved 6 months
after surgery.
