Development of a novel difficulty scoring system for laparoscopic liver resection procedure in patients with intrahepatic duct stones

Table 4 Difficulty factor score classification associated with laparoscopic liver resection

Variables	Variables category	Score
Location of stones	TL	0
	TR	1
Number of stones ≥ 3	No	0
	Yes	2
Stone located in the bile ducts of several grades	Primary bile duct	0
	Secondary bile duct	1
	Tertiary bile duct	2
Previous biliary surgery less than twice	No	0
	Yes	2
Distal bile duct atrophy	No	0
	Yes	1
Total score
≤ 3: Low difficulty
4-5: Medium difficulty
≥ 6: High difficulty

TL: Type left; TR: Type right.