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.