Is intraperitoneal isoperistaltic side-to-side anastomosis a safe surgical procedure in radical colon cancer surgery

Table 1 Clinical characteristics in the intraperitoneal anastomosis and extraperitoneal anastomosis groups before and after matching, n (%)

	Before matching, IA (n = 70)	Before matching, EA (n = 266)	Before matching, P value	After matching, IA (n = 63)	After matching, EA (n = 63)	After matching, P value
Sex			0.266			0.372
Male	34 (48.6)	149 (56)		32 (50.8)	27 (42.9)
Female	36 (51.4)	117 (44)		31 (49.2)	36 (57.1)
Age, years (mean ± SD)	60.86 ± 11.79	59.72 ± 11.97	0.479	61.33 ± 11.56	60.52 ± 11.35	0.638
BMI, kg/m2 (mean ± SD)	22.40 ± 2.60	22.92 ± 3.08	0.194	22.58 ± 2.60	22.93 ± 2.66	0.481
ASA score			0.762			0.433
2	66 (94.3)	245 (92.1)		59 (93.7)	60 (95.2)
3	4 (5.7)	20 (7.5)		4 (6.3)	2 (3.2)
4	0 (0)	1 (0.4)		0 (0)	1 (1.6)
Comorbidity			1.000			0.854
None	45 (64.3)	171 (64.3)		39 (61.9)	40 (63.5)
Yes	25 (35.7)	95 (35.7)		24 (38.1)	23 (36.5)
Tumor site			< 0.001			1.000
Ileocecum	8 (11.4)	14 (5.3)		7 (11.1)	7 (11.1)
Ascending colon	26 (37.2)	61 (22.9)		26 (41.3)	26 (41.3)
Transverse colon	24 (34.3)	21 (7.9)		18 (28.5)	18 (28.5)
Descending colon	11 (15.7)	43 (16.2)		11 (17.5)	11 (17.5)
Sigmoid	1 (1.4)	103 (38.7)		1 (1.6)	1 (1.6)
Upper rectum	0 (0)	24 (9.0)		0 (0)	0 (0)

IA: Intraperitoneal anastomosis; EA: Extraperitoneal anastomosis; BMI: Body mass index; ASA: American Society of Anesthesiologists.

Table 2 Surgical characteristics in the intraperitoneal anastomosis and extraperitoneal anastomosis groups before and after matching, mean ± SD

	Before matching, IA (n = 70)	Before matching, EA (n = 266)	Before matching, P value	After matching, IA (n = 63)	After matching, EA (n = 63)	After matching, P value
Operation time, minutes	217.47 ± 43.33	177.17 ± 46.04	< 0.001	219.11 ± 43.04	194.00 ± 47.04	0.001
Blood loss, mL	55.29 ± 35.21	71.88 ± 55.99	0.010	56.19 ± 36.21	84.76 ± 63.45	0.002
Incision size, cm	3.57 ± 0.97	5.48 ± 1.16	< 0.001	3.49 ± 0.83	5.63 ± 1.32	< 0.001

IA: Intraperitoneal anastomosis; EA: Extraperitoneal anastomosis.

Table 3 Postoperative characteristics in the intraperitoneal anastomosis and extraperitoneal anastomosis groups before and after matching, mean ± SD

	Before matching, IA (n = 70)	Before matching, EA (n = 266)	Before matching, P value	After matching, IA (n = 63)	After matching, EA (n = 63)	After matching, P value
Exhaust time, days	3.21 ± 1.19	4.79 ± 1.84	< 0.001	3.22 ± 1.24	4.86 ± 1.62	< 0.001
Defecation time, days	6.67 ± 1.59	8.26 ± 2.60	< 0.001	6.70 ± 1.64	8.17 ± 1.72	< 0.001
Eating time, days	4.33 ± 1.61	5.52 ± 1.94	< 0.001	4.38 ± 1.68	5.57 ± 1.71	< 0.001
Peritoneal drainage time, days	8.11 ± 2.72	10.62 ± 7.32	0.003	8.24 ± 2.83	9.95 ± 3.26	0.002
Postoperative hospital stay, days	10.64 ± 4.05	12.13 ± 6.21	0.030	10.92 ± 4.18	11.97 ± 5.31	0.124
Complication, n (%)			0.273			0.660
Yes	13 (18.6)	66 (24.8)		12 (19.0)	14 (22.2)
No	57 (81.4)	200 (75.2)		51 (81.0)	49 (77.8)

IA: Intraperitoneal anastomosis; EA: Extraperitoneal anastomosis.

Table 4 Postoperative complications in the intraperitoneal anastomosis and extraperitoneal anastomosis groups after matching

	IA (n = 63)	EA (n = 63)	P value
All, n (%)	12 (19.0)	14 (22.2)	0.660
CD2	10	13	0.489
Paralytic ileus	1	6	0.052
Anastomotic leak	1	0
Delayed healing of incision	1	3
Intra-abdominal infection	3	1	0.310
Pneumonia	2	3
Chyle leak	2	0
CD3	2	1	0.559
Incisional infections	2	1

IA: Intraperitoneal anastomosis; EA: Extraperitoneal anastomosis; CD: Clavien-Dindo classification.

Table 5 Pathological features in the intraperitoneal anastomosis and extraperitoneal anastomosis groups before and after matching, n (%)

	Before matching, IA (n = 70)	Before matching, EA (n = 266)	Before matching, P value	After matching, IA (n = 63)	After matching, EA (n = 63)	After matching, P value
Tumor size, mm (mean ± SD)	4.32 ± 1.74	4.15 ± 1.78	0.463	4.29 ± 1.79	4.11 ± 1.82	0.587
Gross type			0.871			0.202
Protuberant type	33 (47.1)	129 (48.5)		27 (42.8)	34 (54.0)
Ulcerative type	35 (50.0)	132 (49.6)		34 (54.0)	29 (46.0)
Infiltrative type	2 (2.9)	5 (1.9)		2 (3.2)	0 (0)
Histological type			0.599			0.405
Well	3 (4.3)	12 (4.5)		2 (3.2)	2 (3.2)
Mod	58 (82.8)	197 (74.1)		54 (85.7)	47 (74.6)
Por	7 (10.0)	44 (16.5)		5 (7.9)	9 (14.3)
Muc	2 (2.9)	12 (4.5)		2 (3.2)	5 (7.9)
Else	0 (0)	1 (0.4)		0 (0)	0 (0)
Pathological T status			0.568			0.291
Tis	3 (4.3)	4 (1.5)		2 (3.2)	2 (3.2)
1	7 (10.0)	27 (10.2)		7 (11.1)	5 (7.9)
2	6 (8.6)	32 (12.0)		5 (7.9)	6 (9.5)
3	36 (51.4)	120 (45.1)		32 (50.8)	22 (34.9)
4a	18 (25.7)	82 (30.8)		17 (27.0)	28 (44.5)
4b	0 (0)	1 (0.4)		0 (0)	0 (0)
Cleared lymph nodes (mean ± SD)	34.71 ± 16.21	26.29 ± 12.35	< 0.001	33.51 ± 1.86	28.71 ± 11.91	0.031
Pathological N status			0.253			0.137
0	38 (54.3)	171 (64.3)		32 (50.8)	43 (68.3)
1a	16 (22.9)	32 (12.4)		16 (25.4)	9 (14.3)
1b	8 (11.4)	24 (9.0)		8 (12.7)	6 (9.5)
1c	0 (0)	4 (1.5)		0 (0)	0 (0)
2a	5 (7.1)	23 (8.6)		4 (6.3)	5 (7.9)
2b	3 (4.3)	11 (4.2)		3 (4.8)	0 (0)
Neurovascular invasion			0.910			1.000
Yes	30 (42.9)	112 (42.1)		26 (41.3)	26 (41.3)
No	40 (57.1)	154 (57.9)		37 (58.7)	37 (58.7)
Surgical margin			1.000			1.000
Positive	0 (0)	0 (0)		0 (0)	0 (0)
Negative	70 (100)	266 (100)		63 (100)	63 (100)

IA: Intraperitoneal anastomosis; EA: Extraperitoneal anastomosis; Well: Well differentiated adenocarcinoma; Mod: Moderately differentiated adenocarcinoma; Por: Poorly differentiated adenocarcinoma; Muc: Mucinous carcinoma; Else: Other types of tumors.

Table 6 Characteristics in the right-side group after the stratified analysis, mean ± SD

	R-IA (n = 47)	R-EA (n = 47)	P value
Age, years	62.32 ± 10.55	60.19 ± 11.97	0.363
Sex, n (%)			1.000
Male	22 (46.8)	22 (46.8)
Female	25 (53.2)	25 (53.2)
BMI, kg/m2	22.69 ± 2.38	5.66 ± 1.83	0.777
Incision size, cm	3.65 ± 0.85	5.72 ± 1.41	< 0.001
Blood loss, mL	55.96 ± 34.56	88.09 ± 68.45	0.005
Operation time, hours	226.06 ± 40.48	193.57 ± 44.68	< 0.001
Exhaust time, days	3.15 ± 1.32	4.94 ± 1.75	< 0.001
Defecation time, days	6.81 ± 1.61	8.19 ± 1.81	< 0.001
Eating time, days	4.38 ± 1.71	5.66 ± 1.83	0.001
Peritoneal drainage time, days	8.15 ± 3.07	9.98 ± 3.44	0.008
Postoperative hospital stay, days	11.26 ± 4.55	11.63 ± 5.43	0.712
Cleared lymph nodes	37.15 ± 14.17	29.74 ± 11.11	0.006
Complication, n (%)			0.797
Yes	10 (21.3)	9 (19.1)
No	37 (78.7)	38 (80.9)

R: Right; IA: Intraperitoneal anastomosis; EA: Extraperitoneal anastomosis; BMI: Body mass index.

Table 7 Characteristics in the left-side group after the stratified analysis, mean ± SD

	L-IA (n = 16)	L-EA (n = 16)	P value
Age, years	58.44 ± 14.1	61.50 ± 9.57	0.478
Sex, n (%)			0.077
Male	10 (62.5)	5 (68.7)
Female	6 (37.5)	11 (31.3)
BMI, kg/m2	22.23 ± 3.21	23.21 ± 2.90	0.370
Incision size, cm	3.03 ± 0.53	5.38 ± 1.02	< 0.001
Blood loss, mL	56.88 ± 41.91	75.00 ± 46.19	0.254
Operation time, hours	198.69 ± 45.12	196.56 ± 54.95	0.254
Exhaust time, days	3.44 ± 0.96	4.63 ± 1.15	0.004
Defecation time, days	6.38 ± 1.75	8.13 ± 1.45	0.004
Eating time, days	4.38 ± 1.63	5.31 ± 1.30	0.082
Peritoneal drainage time, days	8.50 ± 2.03	9.88 ± 2.78	0.121
Postoperative hospital stay, days	9.94 ± 2.72	12.94 ± 5.00	0.046
Cleared lymph nodes	22.81 ± 11.14	25.69 ± 13.94	0.524
Complication, n (%)			0.200
Yes	2 (12.5)	5 (31.3)
No	14 (87.5)	11 (68.7)

L: Left; IA: Intraperitoneal anastomosis; EA: Extraperitoneal anastomosis; BMI: Body mass index.