Learning curve for a surgeon in robotic pancreaticoduodenectomy through a “G”-shaped approach: A cumulative sum analysis

Table 1 Preoperative characteristics of all the patients in the two phases

Variable	Total	Early (n = 16)	Late (n = 44)	P value
Gender (male/female)	35/25	8/8	27/17
Age	57.32 ± 1.58	55.74 ± 3.45	57.89 ± 1.77	0.55
ASA score
1	42	13	29
2	18	3	15
3	0	0	0
Preoperative
BMI	22.91 ± 0.38	22.99 ± 0.86	22.88 ± 0.42	0.90
CA 19-9 (U/mL)	311.4 ± 81.24	313.4 ± 148.6	337.9 ± 97.66	0.89
ALT	184.1 ± 22.78	103.0 ± 28.08	213.6 ± 28.20	0.03
AST	123.1 ± 13.19	89.79 ± 24.12	135.5 ± 15.45	0.12
Total bilirubin	186.3 ± 17.08	94.45 ± 30.06	218.3 ± 18.29	0.001
Direct bilirubin	110.9 ± 11.33	45.11 ± 16.31	1340 ± 12.32	0.0003
Pathological parameters				0.53
Pancreatic cancer	13	2	11
Solid pseudopapillary tumor	5	0	5
Cholangiocarcinoma	22	6	16
Ampulla cancer	15	7	8
Neuroendocrine tumor	2	0	2
IPMN	2	1	1
Chronic pancreatitis	1	0	1

ASA: American Society of Anesthesiologists; BMI: Body mass index; CA: Carbohydrate antigen; ALT: Alanine transaminase; AST: Aspartate transaminase; IPMN: Intraductal papillary mucinous neoplasm.

Table 2 Details of operation-related information in the two phases

Variable	Total	Early (n = 16)	Late (n = 44)	P value
Operative time (min)	378.55 ± 94.30	480 ± 81.65	331 ± 76.54	< 0.01
Estimated blood loss (mL)	223.3 ± 31.94	308 ± 54.78	169.2 ± 35.33	< 0.01
Conversion to OPD	3 (5%)	2 (12.5%)	1 (2.27%)	0.11
Postoperative stay (d)	19 ± 6.09	22 ± 4.53	17 ± 6.08	< 0.01
Overall complication
Pancreatic fistula	17 (28.3%)	6 (37.5%)	11 (25%)	0.34
Grade A	11 (18.3%)	3 (18.75%)	8 (18.2%)	0.95
Grade B	6 (10%)	3 (18.75%)	3 (6.82%)	0.17
Grade C	0	0	0
Bile leakage	4 (6.67%)	3 (18.75%)	1 (2.27%)	0.024
Gastric fistula	0	0	0
Delayed gastric emptying	16 (26.67%)	8 (50%)	8 (18.18%)	0.01
Wound healing	1	0	1
30-d reoperation	0	0	0
30-d mortality	0	0	0
Postoperative hospital stay (d)	18.8 ± 11.8	22.5 ± 14.5	17.5 ± 9.3	< 0.01

OPD: Open pancreaticoduodenectomy.