Table 2 Similarities and differences with similar studies

Our study

Meta-analysis of single-arm

62

2439

28

ASIA impairment scale grade, urinary system function, gastrointestinal system function

1) Stem cells can improve ASIA grade, urinary system function, and gastrointestinal system function.

2) Stem cell transplantation may cause 28 kinds of AEs, of which the incidence of neuropathic pain, abnormal feeling, muscle spasms, vomit, and urinary tract infection exceeds 20%.

Li et al. [111]

Meta-analysis of head-to-head comparisons

7

275

5

ASIA impairment scale grade, residual urine volume

1) Compared with conventional treatment, stem cells can significantly improve ASIA and improve residual urine volume to a certain extent.

2) More AEs occurred after stem cell transplantation, mainly including fever (22.2%), headache and dizziness (13.1%), neuropathic pain (10.6%), myologic pain (5.09%), and skin rash and itching (3.32%).

Fan et al. [113]

Meta-analysis of head-to-head comparisons

10

377

5

ASIA impairment scale grade, ADL score, residual urine volume

1) Compared with rehabilitation therapy, stem cells can significantly improve ASIA grade and residual urine volume, but have no significant effect on ADL score.

2) Stem cell transplantation has a higher incidence of AEs (RR = 14.49, 95%CI [5.34, 34.08], p < 0.00001), mainly including fever, headache, backache, numbness, and abdominal distension.

Xu et al. [109]

Meta-analysis of head-to-head comparisons

11

499

5

ASIA impairment scale grade, ADL score, residual urine volume

1) Compared with conventional treatment, stem cells can significantly improve ASIA, ADL, and residual urine volume.

2) There were more AEs after stem cell transplantation (RR = 20.34, 95%CI [8.09–51.18], p < 0.001), mainly including fever, headache, backache, numbness, and abdominal distension.

Muthu et al. [110]

Meta-analysis of head-to-head comparisons

19

670

3

ASIA impairment scale grade, ADL score, residual urine volume, bladder function improvement, SSEP improvement

1) The stem cells group showed statistically significant improvement in ASIA grade, bladder function, residual urine volume, and SSEP. However, no significant difference was noted in ADL.

2) More AEs occurred after stem cell transplantation (RR = 4.342, 95%CI [2.248, 6.436], p < 0.001), mainly including fever, headache, and neuropathic pain.

Liu et al. [21]

Network meta-analysis

12

642

3

ASIA impairment scale grade, Barthel index

1) Stem cells combined with rehabilitation training were significantly more effective than rehabilitation training alone in improving ASIA and Barthel index.

2) More adverse effects occurred after stem cell transplantation, mainly including fever (7.59%), headache (5.69%), and neuropathic pain (4.88%).

Tang et al. [20]

Meta-analysis of head-to-head comparisons

9

328

3

ASIA impairment scale grade; urodynamic indices

1) Compared with conventional treatment, stem cells can significantly improve ASIA and improve bladder function.

2) More AEs occurred after stem cell transplantation, mainly including neuropathic pain (RR = 1.58, 95%CI [0.92, 2.72], p = 0.10), fever (RR = 4.22, 95%CI [1.74, 10.22], p = 0.001), and headache (RR = 2.40, 95%CI [0.57, 10.17], p = 0.23).

Johnson et al. [112]

Meta-analysis of head-to-head comparisons

19

224

0

ASIA impairment scale grade

Compared with conventional treatment, stem cells can significantly improve ASIA.

Chen et al. [114]

Network meta-analysis

18

949

4

ASIA impairment scale grade, Barthel index

1) Stem cells significantly improved ASIA grade and Barthel index compared to rehabilitation.

2) More AEs occurred after stem cell transplantation (OR = 14.35, 95%CI [4.28, 48.07], p < 0.001), mainly including fever, headache, back pain, and numbness.