Robotic- vs laparoscopic-assisted proctectomy for locally advanced rectal cancer based on propensity score matching: Short-term outcomes at a colorectal center in China

Table 1 Patient's clinicopathological features in the robotic assisted proctectomy and laparoscopic assisted proctectomy groups for locally advanced rectal cancer

Features	RAP (n = 293)	LAP (n = 293)	P value
Gender			0.8671
Male	168 (57.3)	170 (58.0)
Female	125 (42.7)	123 (42.0)
Age, yr	60 ± 12, 61 (26-89)	60 ± 11, 60 (29-86)	0.9693
Body mass index, kg/m2	23.16 ± 2.51	23.23 ± 2.48	0.7212
Serum CEA level, ng/mL	14.3 ± 46.7, 4.9 (0.8-760.3)	14.5 ± 30.9, 5.8 (0.2-412.8)	0.4293
Type of resection			0.2641
Dixon	240 (81.9)	250 (85.3)
Miles	53 (18.1)	43 (14.7)
pTNM			0.6861
II	64 (21.8)	60 (20.5)
III	229 (78.2)	233 (79.5)
ASA classification			0.5601
1	144 (49.1)	149 (50.9)
2	104 (35.5)	106 (36.9)
3	45 (15.4)	36 (12.3)
Diameter of neoplasm, cm	4.2 ± 1.5, 4.0 (0.2-10.0)	4.3 ± 1.3, 4.3 (0.3-9.0)	0.5543
Distance of tumor and anal, cm4	6.7 ± 2.8, 7.0 (2.0-14.0)	6.8 ± 2.8, 7.0 (2.0-14.0)	0.5753

¹Pearson's Chi-squared test, expressed as n (%).

²Student’s t-test, expressed as mean ± SD.

³Mann–Whitney U test, expressed as mean ± SD and median (range).

⁴The distance between the inferior margin of tumor and the anal verge. ASA: American Society of Anesthesiologists; CEA: Carcinoembryonic antigen; LAP: Laparoscopic assisted proctectomy; RAP: Robotic assisted proctectomy; SD: Standard deviation; TNM: Tumor node metastasis staging.

Table 2 Operative outcomes between the robotic assisted proctectomy group and laparoscopic assisted proctectomy group

Operative outcomes	RAP (n = 293)	LAP (n = 293)	P value
Operative time, min	171 ± 42, 160 (120-385)	145 ± 42, 133 (80-350)	0.0003
Operative blood loss, mL	106 ± 114, 80 (30-1500)	138 ± 111, 100 (40-1200)	0.0003
Median time to first flatus, h	57 ± 11, 56 (28-98)	56 ± 9, 56 (28-100)	0.5343
Median time to liquid diet, h	69 ± 10, 67 (38-108)	69 ± 9, 69 (38-110)	0.3963
Median time to semi-liquid diet, h	83 ± 10, 82 (51-122)	83 ± 9, 83 (53-123)	0.1943
Median volume of pelvic drainage, mL	362 ± 457, 290 (80-4020)	465 ± 564, 310 (100-3820)	0.000 3
Median time to remove pelvic drainage tube, d	7.1 ± 4.2, 6.0 (4.0-29.0)	7.8 ± 4.9, 7.0 (4.0-28.0)	0.0003
Median time to remove urinary catheter, d	3.2 ± 1.0, 3.0 (2.0-7.0)	3.8 ± 1.2, 4.0 (2.0-14.0)	0.0003
Numbers of retrieved lymph nodes	16.0 ± 3.8	15.7 ± 3.7	0.3492
Perineural invasion			0.5571
Yes	124 (42.3)	117 (39.9)
No	169 (57.7)	176 (60.1)
Vascular invasion			0.3341
Yes	91 (31.1)	102 (34.8)
No	202 (68.9)	191 (65.2)
Distal resection margin, cm	2.7 ± 0.6, 2.7 (1.8-7.1)	2.5 ± 0.5, 2.5 (1.6-6.8)	0.0003
Conversion to open laparotomy	7 (2.4)	17 (5.8)	0.0371
Postoperative length of stay, d	9.1 ± 4.9, 8.0 (5.0-32.0)	9.2 ± 5.0, 8.0 (5.0-30.0)	0.4613

¹Pearson's Chi-squared test, expressed as n (%).

²Student’s t-test, expressed as mean ± SD.

³Mann–Whitney U test, expressed as mean ± SD and median (range). LAP: Laparoscopic assisted proctectomy; RAP: Robotic assisted proctectomy; SD: Standard deviation.

Table 3 Complications in the robotic assisted proctectomy group and laparoscopic assisted proctectomy group, n (%)

Complications	RAP (n = 293)	LAP (n = 293)	P value
Patients with complications	39 (13.3)	46 (15.7)	0.4121
Single complication	31 (10.6)	35 (11.9)	0.6011
Multiple complications	8 (2.7)	11 (3.8)	0.4841
Overall complications	47 (16.0)	57 (19.5)	0.280 1
Wound infection	8 (27)	6 (2.0)	0.5881
Delayed gastric emptying	0 (0.0)	1 (0.3)	1.0003
Intestinal obstruction	2 (0.7)	3 (1.0)	1.0002
Intra-abdominal hemorrhage	1 (0.3)	2 (0.7)	1.0002
Anastomotic leakage	13 (4.4)	14 (4.8)	0.8441
Anastomotic bleeding	1 (0.3)	1 (0.3)	1.0002
Pneumonia	4 (1.4)	5 (1.7)	1.0002
Pleural effusion	1 (0.3)	1 (0.3)	1.0002
Infection of presacral space	1 (0.3)	5 (1.7)	0.2182
Intra-abdominal infections	1 (0.3)	2 (0.7)	1.000 2
Infection of incision in perineum	6 (2.0)	5 (1.7)	0.7611
Small intestinal fistula	1 (0.3)	1 (0.3)	1.0002
Peristomal wound infection	1 (0.3)	0 (0.0)	1.0003
Necrosis of enterostomy	1 (0.3)	0 (0.0)	1.0003
Urinary retention	6 (2.0)	10 (3.4)	0.3111
Cerebral infarction	0 (0.0)	1 (0.3)	1.0003
Clavien-Dindo classification
I	15 (5.1)	16 (5.5)	0.8541
II	13 (4.4)	20 (6.8)	0.2101
IIIa	14 (4.8)	16 (5.5)	0.7081
IIIb	4 (1.4)	3 (1.0)	1.0002
V	1 (0.3)	2 (0.7)	1.0002
≥ III	19 (6.5)	21 (7.2)	0.7431
Reoperation	4 (1.4)	3 (1.0)	1.0002
Mortality	1 (0.3)	2 (0.7)	1.0002
Unplanned readmission within 30 d after operation	2 (0.7)	5 (1.7)	0.4472

¹Pearson's Chi-squared test.

²Continuous correction Chi-squared test.

³Fisher’s exact test. LAP: Laparoscopic assisted proctectomy; RAP: Robotic assisted proctectomy.