Comparison between air and carbon dioxide insufflation in the endoscopic submucosal excavation of gastrointestinal stromal tumors

Table 1 Patient characteristics

Group	CO2 insufflation	Air insufflation	P value1
	(n = 30)	(n = 30)
Age, yr, mean ± SD	52.1 ± 5.1	50.9 ± 6.6	0.83
Sex (male/female)	17/13	16/14	0.80
Mean BMI (kg/m2)	21.63	21.79	0.54
Previous surgeries, n (%)
Any prior abdominal surgery	17 (57)	16 (53)	0.80
Cholecystectomy	9 (30)	11 (37)	0.58
Hysterectomy	3 (10)	2 (7)
Liver transplantation	2 (7)	1 (3)
Other2	5 (17)	2 (7)	0.30

¹By χ² for categorical variables and t test for continuous variables;

²Other surgeries include ovarian cystectomy[2], appendectomy[2], laparoscopic gastrectomy[1]. BMI: Body mass index.

Table 2 Endoscopic submucosal excavation treatment characteristics

Group	Location (n)	Diameter (cm)	Operating time (min)	Success rate (%)	Full-thickness isolation (n)
CO2	Esophagus (4)	1.7	41	100	3
	Stomach (22)	1.3	23
	Rectum (2)	1.5	40
	Sigmoid colon (2)	1.9	47
Air	Esophagus (6)	1.1	43	100	2
	Stomach (21)	0.7	31
	Rectum (2)	0.9	38
	Sigmoid colon (1)	1.7	51

Table 3 Comparison of PetCO₂ between the two groups

Time point	CO2 group (mmHg)	Air group (mmHg)	P value
Beginning of ESE	34.01 ± 2.03	33.32 ± 2.21	0.78
Removal of the tumors	31.21 ± 2.35	30.59 ± 2.73	0.73
Wound management	32.75 ± 2.69	32.01 ± 2.22	0.92
10 min after ESE	33.23 ± 2.56	32.61 ± 2.78	0.79

ESE: Endoscopic submucosal excavation.