Machine learning identifies the risk of complications after laparoscopic radical gastrectomy for gastric cancer

Table 1 Demographic and clinical characteristics of the training group and validation groups (mean ± SD)

Characteristic	Training group			Validation group
	LGC (n = 998)	LTG (n = 572)	LDG (n = 426)	LGC (n = 398)	LTG (n = 165)	LDG (n = 233)
Age	59.8 (11.31)	60.0 (11.22)	59.6 (11.44)	57.8 (12.4)	59.2 (12.2)	57.0 (12.4)
Gender
Female	307	156	151	173	45	82
male	691	416	275	342	120	151
BMI	22.6 (3.2)	22.9 (3.2)	22.3 (3.2)	22.6 (3.4)	22.7 (3.6)	22.5 (3.4)
ASA score
2	964	556	408	365	148	217
3	34	16	18	33	17	16
ECOG score
0	810	460	350	142	69	73
1	158	98	60	231	89	142
2	30	14	16	25	7	18
Severe heart disease	4	1	3	22	17	5
Severe lung disease	10	5	5	18	12	6
Hypertension	140	71	69	78	39	39
Diabetes	67	30	37	52	27	25
Operative time (min)	240 (63.0)	246.8 (73.1)	230.9 (44.6)	280.9 (76.4)	308.0 (86.1)	267.2 (68.9)
Bleeding volume (min)	130.5 (115.4)	147.8 (128.5)	107.3 (90.0)	54.3 (57.6)	78.7 (67.4)	57.9 (51.6)
Blood transfusion (mL)	25.5 (138.1)	34.3 (172.3)	13.62 (67.9)	19.0 (132.4)	11.0 (65.1)	22.0 (154.0)
Complication	139	64	75	78	51	27
ClavienDindo
0	859	508	351	320	114	206
1	14	5	9	17	10	7
2	93	34	59	56	38	18
3	29	24	5	5	3	2
4	3	1	2	0	0	0

BMI: Body mass index; LDG: Laparoscopic distal gastrectomy; LTG: Laparoscopic total gastrectomy; LGC: Localized gastric cancer; ASA: Aneshesiologists; ECOG: Eastern Collaborative Oncology Group.

Table 2 Incidence of complications in the training group and validation groups

	Training group	Validation group
Complication	164	78
Anastomotic leakage	23	11
Anastomotic stricture	5	5
Anastomotic bleeding	6	0
Pancreatic fistula	3	0
Gastric and Intestinal stasis	10	0
Bleeding of peritoneal cavity	7	1
Surgical incision infection or fat liquefaction	18	3
Pulmonary infection	42	5
Abdominal infection	27	29
Sepsis	5	0
Urinary tract infection	1	13
Intestinal obstruction	14	7
Lymphorrhea	10	4
Deep vein thrombosis	1	1
Pulmonary embolism	1	1
Cardiac arrhythmia	0	0
Biliary leakage	1	0

Table 3 Univariate analysis of severe complications after laparoscopic distal gastrectomy in gastric cancer patients

Variate	No-severe complication (%)	Severe complication (%)	t/χ2	P value	OR	95%CI
Age group
Age ≤ 65	239	38	1.905	0.168
Age > 65	121	28			1.455	0.852-2.485
Gender
Male	234	41	0.095	0.758
Female	126	25			1.132	0.658-1.948
BMI group
BMI ≤ 28	347	57	9.49	0.002
BMI > 28	13	9			4.215	1.722-10.313
Hb	129.7 ± 26.6	126.8 ± 26.2	0.797	0.424	0.996	0.986-1.006
ALB	40.7 ± 4.85	40.3 ± 4.03	0.707	0.48	0.98	0.927-1.036
Tumor size	3.2 ± 1.8	3.5 ± 2.0	-1.346	0.179	1.101	0.967-1.266
Bleeding volume	103.3 ± 89.2	128.6 ± 91.9	-2.109	0.036	1.003	1.000-1.005
Operative time	230.7 ± 45.1	232.4 ± 42.2	-0.282	0.778	1.001	0.995-1.007
Blood transfusion	6.9 ± 49.86	50.00 ± 121.8	-27.381	< 0.001	1.006	1.003-1.010
Severe heart disease
No	359	64	2.748	0.064
Yes	1	2			11.219	1.002-125.553
Severe lung disease
No	358	63	4.601	0.032
Yes	2	3			8.524	1.396-52.039
Hypertension
No	302	55	0.013	0.91
Yes	58	11			1.041	0.541-2.109
Diabetes
No	329	60	0.016	0.899
Yes	31	6			1.061	0.424-2.654
Surgerical type
Totally	82	20	1.734	0.188
Assisted	278	46			0.678	0.380-1.212
Reconstruction
Billroth I	90	12	6.133	0.105
Billroth II	106	26			1.840	0.878-3.854
Roux-en-Y	113	24			1.593	0.755-3.360
Billroth II + Braun	51	4			0.588	0.180-19.19
ECOG score
0	323	27	95.605	< 0.001
1	34	26			9.148	4.804-17.421
2	3	13			51.840	13.913-193.157
ASA score
2	353	55	29.802	< 0.001	10.086	3.750-27.124

BMI: Body mass index; ASA: Aneshesiologists; ECOG: Eastern Collaborative Oncology Group.

Table 4 Univariate analysis of severe complications after laparoscopic total gastrectomy in gastric cancer patients

Variate	No-severe complication (%)	Severe complication (%)	t/χ2	P value	OR	95%CI
Age group
Age < 65	332	30	4.381	0.036
Age ≥ 65	181	29			1.733	1.032-3.047
Gender
Male	372	44	0.113	0.736
Female	141	15			0.899	0.485-1.667
BMI group
BMI ≤ 28	481	53	1.319	0.251
BMI > 28	32	6			1.702	0.680-4.257
Hb	129.1 ± 25.1	135.2 ± 25.7	-1.754	0.08	1.01	0.999-1.021
ALB	40.4 ± 3.1	39.7 ± 3.2	1.664	0.097	0.928	0.851-1.013
Tumor size	4.0 ± 2.2	3.8 ± 1.9	0.674	0.501	0.95	0.826-1.092
Bleeding volume	150.2 ± 133.5	130.2 ± 70.0	1.114	0.255	0.998	0.995-1.001
Operative time	248.9 ± 73.9	229.0 ± 62.5	1.983	0.048	0.996	0.991-1.000
Intraoperative blood transfusion	37.1 ± 180.8	10.17 ± 54.8	{0.099}	0.754	0.998	0.995-1.002
Severe heart disease
No	512	59	0.115	0.734
Yes	1	0
Severe lung disease
No	511	56	13.461	< 0.001
Yes	2	3			13.687	2.239-83.665
Hypertension
No	452	49	1.245	0.264
Yes	61	10			1.512	0.728-3.140
Diabetes
No	489	53	3.21	0.073
Yes	24	6			2.307	0.902-5.896
Surgerical type
totally	230	35	4.467	0.035
assisted	283	24			0.557	0.322-0.964
ECOG
0	426	34	22.379	< 0.001
1	77	21			3.417	1.883-6.199
2	10	4			5.012	1.493-16.824
ASA
2	505	51	28.024	< 0.001
3	8	8			9.902	3.566-27.499

BMI: Body mass index; ASA: Aneshesiologists; ECOG: Eastern Collaborative Oncology Group.