Multilevel Decompression Surgery for Degenerative Lumbar Spinal Canal Stenosis Is Similarly Effective With Single-Level Decompression Surgery

Tatsuya Yamamoto, MD, PhD; Mitsuru Yagi, MD, PhD; Satoshi Suzuki, MD, PhD; Yohei Takahashi, MD, PhD; Satoshi Nori, MD, PhD; Osahiko Tsuji, MD, PhD; Narihito Nagoshi, MD, PhD; Jun Ogawa, MD, PhD; Morio Matsumoto, MD, PhD; Masaya Nakamura, MD, PhD; Kota Watanabe, MD, PhD

Disclosures

Spine. 2022;47(24):1728-1736.

Abstract and Introduction

Abstract

Study Design: Retrospective case series.

Objective: The purpose of this study was to investigate the outcome of multilevel posterior decompression surgery for degenerative lumbar spinal stenosis compared with single-level surgery.

Summary of Background Data: The clinical outcomes of multilevel decompression surgery are still controversial because previous studies have not been designed to randomize or adjust the patient background.

Materials and Methods: A retrospective review of prospectively collected data from 659 surgically treated lumbar spinal stenosis patients with a minimum 2-year follow-up was performed. Among them, we compared baseline and 2-year postoperative patient-reported outcomes (PROs) including the Visual Analog Scale and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire scores of 122 patients who underwent three or more levels of surgery (M group) and 304 patients who underwent single-level surgery (S group). Further analyses were performed of 116 paired patients from both groups who were propensity score matched by age and baseline PROs.

Results: The number of perioperative complications including extradural hematoma, surgical site infection, and spinal fluid leakage [M vs. S: 10 (8%) vs. 19 (6%), P = 0.47], and frequency of revision surgery [5 (4%) vs. 23 (8%), P = 0.10] were similar between the two groups. In the analysis of propensity score–matched patients, there were comparable improvements in the Visual Analog Scale score for lower back pain (2.6 vs. 2.4, P = 0.55), buttock-leg pain (3.1 vs. 3.4, P = 0.48), and buttock-leg numbness (2.9 vs. 2.9, P = 0.77) in both groups. There were also similar improvements in the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire scores including lower back pain, lumbar function, walking ability, and mental health domains, except for the social life function domain (20.7 ± 26.5 vs. 28.0 ± 27.5, P = 0.04).

Conclusions: Despite the longer surgical time and a larger volume of estimated blood loss, multilevel decompression surgery showed similar improvement to that of single-level surgery in terms of recovery of PROs and frequency of revision surgery. Multilevel decompression surgery provides good clinical outcomes with acceptable complication and revision rates when selecting appropriate patient and spinal levels.

Introduction

Lumbar spinal canal stenosis (LSS) is a common degenerative disorder that presents as lower back pain (LBP), radicular leg pain, and intermittent claudication. The prevalence of LSS in the United States was previously reported to range from 11% to 38% in individuals between the ages of 60 and 69.^[1] Conservative treatment for LSS is effective in patients with mild to moderate symptoms, whereas surgical treatment is desirable for patients presenting with severe gait disturbance, lower extremity muscle weakness, or bladder and bowel dysfunction.^[2,3] Laminectomy has been the gold-standard technique for lumbar decompression surgery, however, several potential postoperative issues must be acknowledged. Damage to the posterior element and subsequent spinal instability are associated with LBP.^[4] Biomechanical studies have indicated that multilevel decompression surgery induces the lumbar spinal instability in flexion.^[5] Furthermore, paravertebral muscle atrophy due to enthesis injury may cause trunk extensor weakness and LBP. The damage to posterior supporting structures, such as the ligamentum complex and paravertebral muscles, tends to increase in severity with the number of decompression levels. As a result, the incidence of postoperative spondylolisthesis was reported to increase in patients treated with multilevel laminectomy than in those treated with single-level laminectomy.^[6] Intraoperative bleeding also tends to increase with the number of decompression levels, which leads to a high incidence of postoperative spinal epidural hematoma.^[7] To date, only a few previous studies have reported the results of posterior decompression surgery for multilevel LSS cases only. Since these preceding studies have not been designed to randomize or adjust the patient background, the clinical outcomes of multilevel decompression surgery are still controversial. When selecting the decompression level in multilevel LSS cases, these information may help us to decide whether to decompress mild stenosis level in addition to severe stenosis level. The purpose of this study was to investigate the various outcomes of multilevel posterior decompression surgery for LSS compared with those of single-level decompression surgery after adjusting the patient background.

1 2 3 4 5

Next Section

Table 1. Demographic and Perioperative Data
	Mean ± SD/n (%)		P Value
	Multilevel Group	Single-level Group	P Value
No. of patients	122	304
Age (y)	72.2 ± 8.5	70.6 ± 9.3	0.057
Sex (male)	86 (70.5)	199 (65.5)	0.318
BMI (kg/m²)	25.0 ± 3.6	23.9 ± 3.4	0.006*
Etiology
LSS	110 (90.2)	270 (88.8)	0.685
DS (Meyerding grade I)	12 (9.8)	34 (11.2)
Smoking status
Current smoker	8 (6.6)	13 (4.3)	0.614
History of smoking	48 (39.3)	121 (39.8)
No smoker	66 (54.1)	170 (55.9)
Comorbidities
Hypertension	65 (53.5)	152 (50.0)	0.541
Diabetes mellitus	30 (24.6)	67 (22.0)	0.570
COPD	4 (3.3)	26 (8.6)	0.054
Coronal disease	10 (8.2)	24 (7.9)	0.917
No. of comorbidities	1.84 ± 1.32	1.81 ± 1.43	0.638
0	16 (13.1)	51 (16.8)
1	40 (32.8)	97 (31.9)
2	33 (27.0)	69 (22.7)
3	20 (16.4)	57 (18.8)
≥4	13 (10.7)	30 (9.9)
mFI-5
Robust	25 (20.5)	72 (23.7)	0.896
Prefrail	55 (45.1)	123 (40.5)
Frail	42 (34.4)	109 (35.9)
Operative data
No. of decompression level	3.2 ± 0.4	1
Time of surgery (min)	105.8 ± 35.4	60.3 ± 28.3	<0.001*
Estimated blood loss (mL)	123.5 ± 158.7	26.9 ± 47.5	<0.001*
Length of hospital stay (d)	12.1 ± 4.8	10.9 ± 4.8	0.006*
Perioperative complication	10 (8.2)	19 (6.3)	0.471
Revision surgery	5 (4.1)	23 (7.6)	0.192

BMI indicates body mass index; COPD, chronic obstructive pulmonary disease; DS, degenerative spondylolithesis; LSS, lumbar spinal stenosis; mFI-5, modified frailty index-5.
*Statistically significant.

Table 2. Comparison of HRQoLs Between the M and S Groups
	Multilevel Group	Single-level Group	P Value
No. of patients	122	304
Baseline HRQoLs
VAS score
Lower back pain	5.9 ± 2.6	5.7 ± 2.8	0.499
Buttock-leg pain	6.2 ± 2.8	6.5 ± 2.7	0.284
Buttock-leg numbness	6.2 ± 2.9	5.8 ± 2.9	0.198
JOABPEQ score
Lower back pain	47.9 ± 34.7	40.1 ± 34.5	0.038*
Lumbar function	55.0 ± 31.2	50.7 ± 30.8	0.198
Walking ability	29.1 ± 26.0	33.0 ± 27.7	0.198
Social life function	39.1 ± 20.4	37.7 ± 20.7	0.597
Mental health	45.4 ± 20.0	43.4 ± 17.4	0.487
2-yr postoperative HRQoLs
VAS score
Lower back pain	3.5 ± 2.7	3.0 ± 2.6	0.105
Buttock-leg pain	3.3 ± 2.8	2.9 ± 2.7	0.267
Buttock-leg numbness	3.6 ± 3.0	2.9 ± 2.9	0.047*
JOABPEQ score
Lower back pain	75.0 ± 29.5	77.1 ± 29.0	0.453
Lumbar function	71.9 ± 23.9	71.6 ± 27.2	0.686
Walking ability	62.9 ± 30.4	71.0 ± 28.9	0.013*
Social life function	58.7 ± 22.1	67.5 ± 24.7	0.001*
Mental health	55.4 ± 20.0	57.4 ± 17.7	0.497
Change of HRQoLs (2-year post-op - baseline)
VAS score
Lower back pain	2.5 ± 3.3	2.7 ± 3.3	0.914
Buttock-leg pain	2.9 ± 2.7	3.6 ± 3.4	0.080
Buttock-leg numbness	2.7 ± 3.4	2.9 ± 3.5	0.650
JOABPEQ score
Lower back pain	28.1 ± 37.0	36.6 ± 38.5	0.034*
Lumbar function	18.0 ± 31.6	20.5 ± 30.2	0.805
Walking ability	34.3 ± 34.8	38.7 ± 34.5	0.316
Social life function	20.7 ± 26.3	29.5 ± 27.6	0.004*
Mental health	11.3 ± 20.9	13.8 ± 18.1	0.230

HRQoL indicates health-related quality of life; JOABPEQ, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire; VAS, Visual Analog Scale.
*Statistically significant.

Table 3. Demographic and Perioperative Data After Propensity Score Matching by Age, Sex, and Baseline Japanese Orthopaedic Association Back Pain Evaluation Questionnaire Score
	n (%)
	Multilevel Group	Single-level Group	P Value
No. of patients	116	116
Age (y)	72.1 ± 8.7	71.5 ± 8.2	0.360
Sex (male)	85 (73.3)	76 (65.5)	0.200
BMI (kg/m²)	25.0 ± 3.5	23.6 ± 3.0	0.010*
Etiology
LSS	105 (90.5)	102 (87.9)	0.525
DS (Meyerding grade I)	11 (9.5)	14 (12.1)
Smoking status
Current smoker	8 (6.6)	5 (4.1)	0.481
History of smoking	47 (60.3)	42 (36.2)
No smoker	61 (51.7)	69 (59.5)
Comorbidities
Hypertension	61 (52.6)	56 (48.3)	0.511
Diabetes mellitus	28 (24.1)	24 (20.7)	0.529
COPD	4 (3.4)	13 (10.7)	0.023*
Coronal disease	9 (7.8)	9 (7.8)	1
No. of comorbidities	1.81 ± 1.33	1.78 ± 1.36	0.820
0	16 (13.8)	17 (14.7)	0.773
1	39 (33.6)	42 (36.2)
2	31 (26.7)	25 (21.6)
3	18 (15.5)	19 (16.4)
≥4	12 (10.3)	13 (11.2)
mFI-5
Robust	25 (21.6)	27 (23.3)	0.391
Prefrail	53 (45.7)	43 (37.1)
Frail	38 (32.8)	46 (39.7)
Operative data
No. of decompression level	3.2 ± 0.4	1
Time of surgery (min)	104.8 ± 35.3	57.2 ± 26.3	<0.001*
Estimated blood loss (mL)	119.8 ± 157.0	20.5 ± 38.0	<0.001*
Length of hospital stay (d)	11.9 ± 4.8	10.7 ± 5.3	0.014*
Perioperative complication	9 (7.8)	9 (7.8)	1
Revision surgery	4 (3.4)	9 (7.8)	0.153

Table 4. Comparison of HRQoLs Between the M and S Groups After Propensity Score Matching by Age, Sex, and Baseline JOABPEQ Score
	Mean ± SD
	Multilevel Group	Single-level Group	P Value
No. of patients	116	116
Baseline HRQoLs
VAS score
Lower back pain	5.9 ± 2.5	5.6 ± 2.8	0.367
Buttock-leg pain	6.3 ± 2.7	6.5 ± 2.7	0.399
Buttock-leg numbness	6.3 ± 2.8	5.9 ± 2.9	0.284
JOABPEQ score
Lower back pain	48.1 ± 34.3	43.3 ± 35.4	0.322
Lumbar function	56.2 ± 30.9	54.0 ± 30.7	0.559
Walking ability	29.3 ± 26.1	34.6 ± 27.8	0.110
Social life function	39.9 ± 20.2	38.9 ± 21.1	0.827
Mental health	45.7 ± 20.1	44.3 ± 18.0	0.647
2-yr postoperative HRQoLs
VAS score
Lower back pain	3.4 ± 2.7	3.2 ± 2.7	0.514
Buttock-leg pain	3.2 ± 2.8	3.2 ± 2.9	0.942
Buttock-leg numbness	3.5 ± 3.1	3.4 ± 3.7	0.353
JOABPEQ score
Lower back pain	76.5 ± 28.7	75.8 ± 28.7	0.879
Lumbar function	73.1 ± 23.6	69.6 ± 28.1	0.668
Walking ability	64.1 ± 29.8	71.8 ± 28.9	0.055
Social life function	59.6 ± 21.5	67.3 ± 24.7	0.018*
Mental health	55.8 ± 20.0	58.1 ± 17.9	0.498
Change of HRQoLs (2-yr postoperative−baseline)
VAS score
Lower back pain	2.6 ± 3.1	2.4 ± 3.2	0.546
Buttock-leg pain	3.1 ± 3.2	3.4 ± 3.7	0.483
Buttock-leg numbness	2.9 ± 3.2	2.9 ± 3.7	0.772
JOABPEQ score
Lower back pain	28.6 ± 36.3	31.2 ± 36.3	0.554
Lumbar function	17.8 ± 31.6	15.6 ± 30.4	0.331
Walking ability	34.9 ± 34.9	36.4 ± 34.3	0.719
Social life function	20.7 ± 26.5	28.0 ± 27.5	0.042*
Mental health	11.0 ± 20.8	13.8 ± 17.8	0.322

HRQoL indicates health-related quality of life; JOABPEQ, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire; VAS, Visual Analog Scale.
*Statistically significant.