Patient Characteristics Between TRDG group and RADG group.
In this study, patients were propensity score-matched for sex, age, BMI, ASA score, maximum tumour diameter, degree of histological differentiation, pathological TNM stage, pathological T stage, pathological N stage, and Lauren classification. 306 patients were successfully matched. Before propensity matching, the distribution of Pathological TNM stage (P = 0.009) and Pathological N Stage (P < 0.001) in the TRDG and RADG groups was not balanced. After PSM, the baseline information of all 306 patients was balanced and comparable (P > 0.05) (Table 1).
Table 1
Comparison of baseline data between TRDG group and RADG group before and after propensity score matching.
Baseline
characteristics
|
Before PSM
|
After PSM
|
TRDG
(n = 160)
|
RADG
(n = 453)
|
p
|
TRDG
(n = 102)
|
RADG
(n = 204)
|
p
|
Age at surgery, median (IQR) ,years
|
59
(49–64)
|
58(52–64)
|
0.540
|
59(51–64)
|
59(52–64)
|
0.900
|
Sex, n (%)
|
|
|
0.335
|
|
|
0.626
|
Male
|
85(53.1)
|
260(57.5)
|
|
54(52.9)
|
114(55.9)
|
|
Female
|
75(46.9)
|
192(42.5)
|
|
48(47.1)
|
90(44.1)
|
|
ASA score, n (%)
|
|
|
0.254
|
|
|
0.842
|
1
|
41(25.6)
|
89(19.7)
|
|
21(20.6)
|
37(18.1)
|
|
2
|
72(45.0)
|
210(46.5)
|
|
50(49.0)
|
100(49.1)
|
|
3
|
47(29.4)
|
153(33.8)
|
|
31(30.4)
|
67(32.8)
|
|
BMI,median (IQR), kg/m2
|
21.7
(19.8–24.4)
|
21.8
(19.8–23.8)
|
0.532
|
21.5
(19.4–24.1)
|
21.8(19.8–23.9)
|
0.792
|
Maximum tumour diameter, median (IQR),cm
|
4.0(3.0–5.0)
|
4.0(3.0–5.0)
|
0.425
|
4.0
(3.0–5.0)
|
4.0(3.0–5.0)
|
0.327
|
Histological differentiation, n (%)
|
|
|
0.067
|
|
|
0.406
|
Well
|
23(14.4)
|
104(23.0)
|
|
23(22.5)
|
39(19.1)
|
|
Moderate
|
72(45.0)
|
187(41.4)
|
|
45(44.2)
|
81(39.7)
|
|
Poor
|
65(40.6)
|
161(35.6)
|
|
34(33.3)
|
84(41.2)
|
|
Pathological TNM stage,n (%)
|
|
|
0.009
|
|
|
0.969
|
I
|
51(31.9)
|
98(21.7)
|
|
21(20.6)
|
41(20.1)
|
|
II
|
62(38.7)
|
168(37.2)
|
|
36(35.3)
|
75(36.8)
|
|
III
|
47(29.4)
|
186(41.1)
|
|
45(44.1)
|
88(43.1)
|
|
Pathological T stage, n (%)
|
|
|
0.105
|
|
|
0.796
|
1
|
31(19.3)
|
89(19.7)
|
|
15(14.7)
|
30(14.7)
|
|
2
|
62(38.8)
|
138(30.5)
|
|
26(25.5)
|
60(29.4)
|
|
3
|
47(29.4)
|
178(39.4)
|
|
46(45.1)
|
91(44.6)
|
|
4
|
20(12.5)
|
47(10.4)
|
|
15(14.7)
|
23(11.3)
|
|
Pathological N Stage, n (%)
|
|
|
0.000
|
|
|
0.766
|
0
|
61(38.2)
|
126(27.9)
|
|
31(30.4)
|
60(29.4)
|
|
1
|
49(30.6)
|
95(21.0)
|
|
22(21.5 )
|
39(19.1)
|
|
2
|
21(13.1)
|
120(26.5)
|
|
21(20.6)
|
53(26.0)
|
|
3
|
29(18.1)
|
111(24.6)
|
|
28(27.5)
|
52(25.5)
|
|
Lauren classification,n (%)
|
|
|
0.771
|
|
|
0.443
|
intestinal
|
84(52.5)
|
246(54.4)
|
|
58(56.9)
|
109(53.4)
|
|
diffuse
|
49(30.6)
|
125(27.7)
|
|
30(29.4)
|
55(27.0)
|
|
mixed
|
27(16.9)
|
81(17.9)
|
|
14(13.7)
|
40(19.6)
|
|
Note: Values are presented as mean ± SD, median and IQR (interquartile range), or n (%).
Abbreviations: RADG, robotic-assisted distal gastrectomy; TRDG, total robotic distal gastrectomy. BMI, body mass index; ASA, American society of anesthesiologists.
Comparison of Perioperative Indexes Between TRDG group and RADG group.
In the perioperative data of the two groups, the operative time (TRDG group 149.3 ± 34.4 min vs RADG group 142.7 ± 36.7 min, P = 0.128) and intraoperative blood loss (TRDG group 74.4 ± 35.2 ml vs RADG group 79.1 ± 27.7 ml, P = 0.198) were similar. However, the TRDG group was superior to the RADG group in terms of postoperative recovery of gastrointestinal function (TRDG group 49.3 ± 17.3hour vs RADG group 54.4 ± 19.1hour, P = 0.025). As a result, the number of postoperative hospitalization days was significantly less in the TRDG group than in the RADG group (TRDG group 8.5 ± 4. 3day vs. RADG group 10.0 ± 4.6day, P = 0.006). However hospitalization costs remained at the same level in both groups (TRDG group 11078.6 ± 3082.0$ vs RADG group 10942.3 ± 3940.9$, P = 0.760). In addition, the total incision length was shorter in the TRDG group than in the RADG group (TRDG group 6.8 ± 0.3 cm vs. RADG group 10.6 ± 0.9 cm, P < 0.001). There were 21 complications in the TRDG group, with 4 anastomotic fistulas and 2 anastomotic hemorrhages. In the RADG group, there were 38 complications, with 8 anastomotic fistulas and 3 anastomotic hemorrhages. There were 38 complications in the RADG group, including 8 anastomotic fistulas and 3 anastomotic hemorrhages. There was no statistically significant difference between the two groups in terms of complications. It is worth mentioning that no wound-related complications occurred in the TRDG group, while seven occurred in the RADG group. In the pathologic data, the number of lymph nodes (P = 0.506), nerves (P = 0.141), and vascular invasion (P = 0.494) harvested in the two groups were not significantly different (Table 2). In the postoperative inflammatory response data of the two groups, the indexes of white blood cell counts and C protein response levels were lower in the TRDG group than in the RADG group on postoperative days 1, 3, and 5 (P < 0.001, P < 0.001). The VAS scores in the TRDG group were lower than in the RADG group (P < 0.001), and at the same time, the TRDG group required fewer additional analgesic medications than did the RADG group (P = 0.013) (Table 3, Fig. 3).
Table 2
Comparison of Postoperative Conditions between TRDG group and RADG group after PSM.
outcome
|
After PSM
|
TRDG(n = 102)
|
RADG(n = 204)
|
p
|
Operative time, mean(SD),min
|
149.3(34.4)
|
142.7(36.7)
|
0.128
|
Estimated blood loss ,mean(SD),ml
|
74.4(35.2)
|
79.1(27.7)
|
0.198
|
1st flatus, mean(SD),hour
|
49.3(17.3)
|
54.4(19.1)
|
0.025
|
1st oral feeding ,mean(SD),hour
|
68.3(20.2)
|
73.0(16.4)
|
0.031
|
Postoperative hospital stay, mean(SD),d
|
8.5(4.3 )
|
10.0(4.6)
|
0.006
|
Total length of abdominal incision,mean(SD),cm
|
6.8(0.3)
|
10.6(0.9)
|
<0.001
|
Total hospitalization cost, mean(SD),$
|
11078.6(3082.0)
|
10942.3(3940.9)
|
0.760
|
Postoperative complication,n(%)
|
21(20.6)
|
38(18.6)
|
0.682
|
Anastomotic leakage
|
4(3.9)
|
8(3.9)
|
|
Anastomotic bleeding
|
2(2.0)
|
3(1.5)
|
|
Ileus
|
3(2.9)
|
3(1.5)
|
|
Wound-related
|
0(0)
|
7(3.4)
|
|
Urinary retention or infection
|
2(2.0)
|
2(1.0)
|
|
Pulmonary infection
|
5(4.9)
|
3(1.5)
|
|
Vomiting
|
3(2.9)
|
5(2.5)
|
|
Others
|
2(2.0)
|
7(3.4)
|
|
Harvested lymph nodes, median (IQR), n
|
25.0(21.0–31.0)
|
25.0(20.0–31.0)
|
0.506
|
Perineural invasion,n(%)
|
75(73.5)
|
133(65.2)
|
0.141
|
Lymphatic or vascular invasion,n(%)
|
65(63.7)
|
138(67.6)
|
0.494
|
Positive margin
|
0(0)
|
0(0)
|
NA
|
Note: Values are presented as mean ± SD, median and IQR (interquartile range), or n (%).
Abbreviations: RADG, robotic-assisted distal gastrectomy; TRDG, total robotic distal gastrectomy.
Table 3
Comparison of postoperative stress response and pain condition of patients between TRDG group and RADG group.
Variable
|
After PSM
|
TRDG(n = 102)
|
RADG(n = 204)
|
p
|
Postoperative white blood cell,mean(SD),count /l
|
|
|
<0.001*
|
Day 1
|
12.9(2.2)
|
13.5(2.9)
|
|
Day 3
|
11.0(2.2)
|
11.2(2.7)
|
|
Day 5
|
8.7(2.2)
|
9.6(2.7)
|
|
Postoperative C-reactive protein,mean(SD),mg/l
|
|
|
<0.001*
|
Day 1
|
68.3(13.8)
|
73.3(14.8)
|
|
Day 3
|
44.0(13.6)
|
48.4(15.0)
|
|
Day 5
|
31.4(13.6)
|
37.0(14.1)
|
|
VAS score, ,mean(SD)
|
|
|
<0.001*
|
Day 1
|
3.7(1.2)
|
5.0(1.3)
|
|
Day 3
|
2.6(1.1)
|
3.5(1.4)
|
|
Day 5
|
1.5(0.7)
|
2.0(1.0)
|
|
Usage of additional analgesics,(n)%
|
18(17.6)
|
63(30.9)
|
0.013
|
Note: Values are presented as Mean (SD). *The p value was calculated by a two-way repeated measures ANOVA.
Abbreviations: RADG, robotic-assisted distal gastrectomy; TRDG, total robotic distal gastrectomy.
Comparison of Short-Term Quality of Life Between TRDG group and RADG group.
In this study, the Body image questionnaire was used to compare the body imagery of the two groups of patients at 3 months postoperatively. The questionnaire has 8 scoring items. Of these, items 1–5 assessed the Body image scale and items 6–8 assessed the Cosmetic scale. The BIQ scores in the TRDG group were better than those in the RADG group (p = 0.015) (Table 4, Fig. 4). In terms of quality of life assessment at 3 months postoperatively, the TRDG group had better physical functioning (P = 0.039), role functioning (P = 0.046), and overall health functioning (P = 0.021) than the RADG group. Meanwhile, the TRDG group had milder symptoms of fatigue (P = 0.037) and pain (P < 0.001) (Fig. 5). Meanwhile, the PASQ Total Subscale Score (P < 0.001) and Global Subscale Score (P < 0.001) were significantly lower in the TRDG group than in the RADG group at 3 months postoperatively (Table 5).
Table 4
Comparison of BIQ Scores of patients in TRDG group and RADG group after PSM.
Subscale
|
After PSM
|
TRDG(n = 102)
|
RADG(n = 204)
|
p
|
Body image scale (1–5),median(IQR)
|
7.0(6.0-7.3)
|
9.0(8.0–10.0)
|
<0.001
|
Cosmetic scale (6–8),median(IQR)
|
21.0(20.0–22.0)
|
19.0(17.0–19.0)
|
<0.001
|
Body image questionnaire,median(IQR)
|
27.0(26.0–29.0)
|
27.0(27.0–28.0)
|
0.015
|
Note: Values are presented as median and IQR (interquartile range).
Abbreviations: RADG, robotic-assisted distal gastrectomy; TRDG, total robotic distal gastrectomy.
Table 5
Comparison of PSAQ Responses of Patients between TRDG group and RADG group.
Subscale
|
Total Subscale Score
|
Global Subscale Score
|
TRDG(n = 102)
|
RADG(n = 204)
|
P
|
TRDG(n = 102)
|
RADG(n = 204)
|
P
|
Appearance
|
14.0(11.0–16.0)
|
14.0(13.0–17.0)
|
0.003
|
2.0(1.0–3.0)
|
3.0(1.0–3.0)
|
0.009
|
Symptoms
|
9.0(7.0–14.0)
|
10.0(8.0–12.0)
|
0.033
|
2.0(1.0–3.0)
|
2.0(2.0–3.0)
|
0.010
|
Scar Consciousness
|
7.0(6.0–9.0)
|
8.0(7.0-9.5)
|
0.008
|
2.0(1.0–3.0)
|
2.0(1.0–3.0)
|
0.865
|
Satisfaction with Appearance
|
9.0(8.0–9.0)
|
10.5(9.0–13.0)
|
<0.001
|
2.0(1.0–3.0)
|
2.0(2.0–3.0)
|
0.029
|
Satisfaction with Symptoms
|
8.0(6.0–9.0)
|
7.0(6.0–9.0)
|
0.366
|
2.0(1.0–3.0)
|
2.0(2.0–3.0)
|
<0.001
|
Total
|
48.0(45.0–52.0)
|
50.5(47.0–61.0)
|
<0.001
|
11.0(8.0–12.0)
|
12.0(10.0–13.0)
|
<0.001
|
Notes: Values are presented as median and IQR (interquartile range).
Abbreviations: RADG, robotic-assisted distal gastrectomy; TRDG, total robotic distal gastrectomy. PSAQ, Patient Scar Assessment Questionnaire and Scoring System.
Long-Term Survival Outcomes Between TRDG group and RADG group.
At last follow-up through June 30, 2023, the median follow-up was 26 months (6–83) in the TRDG group and 28 months (6–83) in the RADG group. The 3-year overall survival rate was 70.8% in the TRDG group and 72.8% in the RADG group, and the Lg-rank test showed no significant difference in overall survival between the two groups (P = 0.236). Moreover, no significant difference between the two groups was observed in 3-year disease-free survival (60.1% in the TRDG group vs 68.9% in the RADG group, P = 0.179) (Fig. 6).