Robotic natural orifice specimen extraction surgery I-type F method vs conventional robotic resection for lower rectal cancer

Table 1 Clinical and pathological features of the patient

Baseline characteristics	R-NOSES I-F (n = 22)	RLRC (n = 76)	Ρ value
Age (year)	56.5 ± 8.9	59.5 ± 11.1	0.107
BMI (kg/m2)	21.8 ± 2.5	22.6 ± 2.0	0.136
Gender			0.580
Male	8 (36.4)	45 (59.2)
Female	14 (63.6)	31 (40.8)
ASA score			0.552
I, II	5 (22.7)	11 (14.5)
III	17 (77.3)	65 (85.5)
Previous history of abdominal surgery	4 (18.2)	13 (17.1)	1.000
Maximum circumferential diameter of specimen (cm)			0.217
< 5	19 (86.4)	56 (73.7)
≥ 5	3 (13.6)	20 (26.3)
Tumour location from anal verge (cm)	4.3 ± 1.2	4.5 ± 0.9	0.278
Abnormal serum CEA (ng/mL)			0.700
≤ 5	16 (72.7)	52 (68.4)
> 5	6 (27.3)	24 (31.6)
Specimen length (cm)	11.4 ± 2.2	12.8 ± 3.1	0.068
Distal margin (cm)	1.1 ± 0.7	1.1 ± 0.8	0.737
Grade of differentiation			0.976
Well	3 (13.6)	12 (15.8)
Moderate	16 (72.7)	52 (68.4)
Poor	2 (9.1)	7 (9.2)
Mucinous	1 (4.5)	5 (6.6)
T stage			0.376
T0, Tis, T1	6 (27.3)	12 (15.8)
T2	7 (31.8)	17 (22.4)
T3	5 (22.7)	27 (35.5)
T4	4 (18.2)	20 (26.3)
N Stage			0.511
N0	14 (63.6)	46 (60.5)
N1	7 (31.8)	20 (26.3)
N2	1 (4.5)	10 (13.2)
pTNM			0.110
0, I	12 (54.5)	23 (30.3)
II	4 (18.2)	23 (30.3)
III	6 (27.3)	30 (39.5)
Number of lymph nodes harvested (n)	14.2 ± 7.3	13.7 ± 6.0	0.759
Nerve violation	9 (40.9)	30 (39.5)	0.904
Lymphovascular violation	7 (31.8)	17 (22.4)	0.364

R-NOSES I-F: Robotic resection using the natural orifice specimen extraction surgery I-type F method; RLRC: Robotic-assisted low rectal cancer resection; BMI: Body mass index; ASA: American Society of Anesthesiologists; CEA: Carcinoembryonic antigen; TNM: Tumor node metastasis staging.

Table 2 Perioperative outcomes

Outcomes	R-NOSES I-F (n = 22)	RLRC (n = 76)	Ρ value
Surgery time (min)	173.0 ± 39.5	187.3 ± 50.9	0.389
Intraoperative blood loss (mL)	89.6 ± 47.9	74.5 ± 62.8	0.068
Prophylactic stoma, n (%)	7 (31.8)	36 (47.4)	0.196
VAS score
POD1	1.7 ± 0.7	2.2 ± 0.6	0.003
POD3	1.5 ± 0.6	1.6 ± 0.6	0.411
POD5	1.1 ± 0.6	1.2 ± 0.4	0.247
Time to pass flatus (d)	2.7 ± 0.6	3.5 ± 0.7	< 0.001
Postoperative hospital stay (d)	11.1 ± 5.2	9.9 ± 5.1	0.091
Hospitalization costs ($)	85098.7 ± 11067.9	82267.9 ± 14993.9	0.130
Postoperative complications, n (%)			0.632
Anastomosis Leakage, n (%)	2 (9.1)	2 (2.6)
Pelvic hemorrhage	0	1 (1.3)
Abdominal infection	0	1 (1.3)
Ileus, n (%)	1 (4.5)	1 (1.3)
Incision infection, n (%)	0	2 (2.6)
Incisional hernia of the abdominal wall, n (%)	0	4 (5.3)
Urinary retention	0	1 (1.3)
White blood cell count (× 109/L)
POD1	9.0 ± 2.8	9.4 ± 2.9	0.462
POD3	7.6 ± 2.2	8.5 ± 3.0	0.321
POD5	6.8 ± 2.1	8.1 ± 4.3	0.112
Neutrophil count (× 109/L)
POD1	7.8 ± 2.6	8.1 ± 2.7	0.579
POD3	6.0 ± 2.0	6.6 ± 3.0	0.563
POD5	5.1 ± 2.0	5.9 ± 2.7	0.266
Body temperature (℃)
POD1	36.9 ± 0.4	37.0 ± 0.4	0.600
POD2	37.1 ± 0.6	36.9 ± 0.4	0.057
POD3	37.0 ± 0.4	36.9 ± 0.4	0.295
POD4	36.8 ± 0.4	36.7 ± 0.4	0.300
POD5	36.9 ± 0.7	36.7 ± 0.5	0.166

R-NOSES I-F: Robotic resection using the natural orifice specimen extraction surgery I-type F method; RLRC: Robotic-assisted low rectal cancer resection; VAS: Visual analog scale; POD: Postoperative days.

Table 3 Postoperative chemotherapy and follow-up results

Outcomes	R-NOSES I-F (n = 22)	RLRC (n = 76)	Ρ value
Postoperative chemotherapy			0.995
XELOX	7 (31.8)	24 (31.6)
Fluorouracil monotherapy	3 (13.6)	11 (14.5)
Defecation and urination function scores
Wexner	4.9 ± 2.6	5.2 ± 3.1	0.817
LARS	15.3 ± 9.1	12.8 ± 10.1	0.177
IPSS	3.7 ± 4.6	3.5 ± 2.9	0.255
Status at last follow-up			0.291
Local recurrence	1 (4.5)	0
Liver metastasis	0	4 (5.3)
Lung metastasis	0	3 (3.9)
Pelvic metastasis	0	2 (2.6)
Dead	0	2 (2.6)

R-NOSES I-F: Robotic resection using the natural orifice specimen extraction surgery I-type F method; RLRC: Robotic-assisted low rectal cancer resection; Wexner: Wexner Incontinence Score; LARS: Low Anterior Resection Syndrome rating scale; IPSS: International Prostate Symptom Score.