Magnetic resonance imaging-based deep learning model to predict multiple firings in double-stapled colorectal anastomosis

Table 1 Clinicopathological characteristics of patients in the training set

Number of linear stapler cartridges	≥ 3	≤ 2	P value
	n = 48 (18.5%)	n = 212 (81.5%)
Sex, n (%)			0.125
Male	38 (79.2)	144 (67.9)
Female	10 (20.8)	68 (32.1)
Age (y), median (quartile)	62 (55-71)	63 (55-68)	0.749
BMI (Kg/m2), median (quartile)	23.5 (21.1-25.3)	22.9 (21.3-25.1)	0.942
Diabetes mellitus, n (%)			0.801
Yes	7 (14.6)	28 (13.2)
No	41 (85.4)	184 (86.8)
Hemoglobin (g/L), median (quartile)	136 (124-143)	133 (124-144)	0.540
Albumin (g/L), median (quartile)	39 (36-41)	40 (37-42)	0.015
CEA (ng/mL), median (quartile)	4.27 (2.11-7.08)	3.05 (2.11-5.61)	0.147
nCRT, n (%)			0.865
Yes	13 (27.1)	60 (28.3)
No	35 (72.9)	152 (71.7)
Distance from anus (cm), median (quartile)	7.2 (5.9-8.4)	7.0 (5.6-8.7)	0.842
CRM evaluated by MRI, n (%)			0.103
Positive	16 (33.3)	47 (22.2)
Negative	32 (66.7)	165 (77.8)
Operation time (min), median (quartile)	139 (111-180)	143 (116-175)	0.526
Length of cartridges used, n (%)			0.113
Only 60 mm	42 (87.5)	200 (94.3)
45 mm ± 60 mm	6 (12.5)	12 (5.7)
Anastomotic leakage, n (%)			0.018
Yes	12 (25.0)	25 (11.8)
No	36 (75.0)	187 (88.2)
Tumor size (cm), median (quartile)	3.7 (3.1-5.1)	3.5 (2.9-4.2)	0.091
T stage, n (%)			0.213
T ≤ 2	11 (22.9)	68 (32.1)
T 3-4	37 (77.1)	144 (67.9)
N stage, n (%)			0.879
N0	25 (52.1)	113 (53.3)
N+	23 (47.9)	99 (46.7)
DRM, n (%)			0.395
≤ 5 mm	4 (8.3)	27 (12.7)
> 5 mm	44 (91.7)	185 (87.3)

BMI: Body mass index; CEA: Carcinoma embryonic antigen; nCRT: Neoadjuvant chemoradiotherapy; CRM: Circumferential resection margin; MRI: Magnetic resonance imaging; DRM: Distal resection margin.

Table 2 Risk factors of ≥ 3 linear staplers in the training set

Factors	Univariate analysis		Multivariate analysis
	OR (95%CI)	P value	OR (95%CI)	P value
Sex (M/F)	0.56 (0.26, 1.18)	0.125	NA	NA
Age (yr) (≥ 70/< 70)	1.60 (0.76, 3.29)	0.205	NA	NA
BMI (Kg/m2) (≥ 25/ < 25)	1.24 (0.63, 2.44)	0.542	NA	NA
Diabetes mellitus (Y/N)	1.12 (0.46, 2.75)	0.801	NA	NA
Albumin (g/L) (< 35/≥ 35)	2.42 (0.92, 6.37)	0.074	NA	NA
CEA (ng/mL) (> 5/≤ 5)	1.99 (1.04, 3.81)	0.038	2.11 (1.08, 4.12)	0.028
nCRT (Y/N)	0.94 (0.47, 1.90)	0.865	NA	NA
Distance from anus (cm) (< 5/≥ 5)	0.60 (0.20, 1.79)	0.358	NA	NA
CRM evaluated by MRI (+/-)	1.76 (0.89, 3.47)	0.103	NA	NA
Length of cartridges (mm) (45/60)	0.42 (0.15, 1.18)	0.113	NA	NA
Tumor size (cm) (≥ 5/< 5)	3.38 (1.55, 7.37)	0.002	3.57 (1.61, 7.89)	0.002

OR: Odds ratio; CI: Confidence interval; NA: Not applicable; BMI: Body mass index; CEA: Carcinoma embryonic antigen; nCRT: Neoadjuvant chemoradiotherapy; CRM: Circumferential resection margin; MRI: Magnetic resonance imaging.

Table 3 Comparison between the training set and the testing set

	Testing set	Training set	P value
	n = 68	n = 260
Sex, n (%)			0.543
Male	45 (66.2)	182 (70.0)
Female	23 (33.8)	78 (30.0)
Age (yr), median (quartile)	63 (57-71)	63 (55-68)	0.322
BMI (Kg/m2), median (quartile)	23.7 (22.0-25.0)	22.9 (21.3-25.1)	0.248
Diabetes mellitus, n (%)			0.303
Yes	6 (8.8)	35 (13.5)
No	62 (91.2)	225 (86.5)
Albumin (g/L), median (quartile)	39 (36-41)	40 (37-42)	0.111
CEA (ng/mL), n (%)		(Missing=5)	0.863
> 5	21 (30.9)	76 (29.8)
≤ 5	47 (69.1)	179 (70.2)
nCRT, n (%)			0.081
Yes	12 (17.6)	73 (28.1)
No	56 (82.4)	187 (71.9)
Distance from anus (cm), median (quartile)	7.1 (5.8-8.7)	7.0 (5.6-8.7)	0.828
CRM evaluated by MRI, n (%)			0.051
Positive	9 (13.2)	63 (24.2)
Negative	59 (86.8)	197 (75.8)
Tumor size (cm), n (%)			0.340
≥ 5	6 (8.8)	34 (13.1)
< 5	62 (91.2)	226 (86.9)
Number of linear stapler cartridges, n (%)			0.470
≥ 3	10 (14.7)	48 (18.5)
≤ 2	58 (85.3)	212 (81.5)
Length of cartridges used, n (%)			0.603
Only 60 mm	62 (91.2)	242 (93.1)
45 mm ± 60 mm	6 (8.8)	18 (6.9)
Anastomotic leakage, n (%)			0.686
Yes	11 (16.2)	37 (14.2)
No	57 (83.8)	223 (85.8)

BMI: Body mass index; CEA: Carcinoma embryonic antigen; nCRT: Neoadjuvant chemoradiotherapy; CRM: Circumferential resection margin; MRI: Magnetic resonance imaging.