Predicting portal venous anomalies by left-sided gallbladder or right-sided ligamentum teres hepatis: A large scale, propensity score-matched study

Table 1 Patient demographics in the four subgroups

Variables		RGB (n = 8516)	LGB (n = 36)	RSLT (n = 34)	typical LT (n = 8518)
Age (yr)1		70.8 ± 15.9	59.6 ± 18.9	62.9 ± 17.7	79.5 ± 19.1
Sex, n (%)	No. of men	4460 (52.4)	23 (63.9)	21 (61.8)	4462 (52.4)
	No. of women	4056 (47.6)	13 (36.1)	13 (38.2)	4056 (47.6)
Chronic liver disease, n (%)	Hepatitis B virus	962 (11.3)	6 (16.7)	6 (17.6)	962 (11.3)
	Hepatitis C virus	281 (3.3)	1 (2.8)	0 (0.0)	282 (3.3)
	Other diseases	2520 (29.6)	8 (22.2)	8 (23.5)	2520 (29.6)
	None	4753 (55.8)	21 (58.3)	20 (58.8)	4754 (55.8)
Comorbidity, n (%)	Hepatocellular carcinoma	911 (10.7)	4 (11.1)	2 (5.9)	913 (10.7)
	Non-HCC cancer	4243 (49.8)	18 (50.0)	18 (52.9)	4243 (49.8)
	Cardiovascular disease	2127 (25.0)	10 (27.8)	8 (23.5)	2129 (25.0)
	Chronic kidney disease	845 (9.9)	4 (11.1)	5 (14.7)	844 (9.9)
	Diabetes mellitus	1899 (22.3)	6 (16.7)	9 (26.5)	1896 (22.3)
	Cholelithiasis	732 (8.6)	3 (8.3)	3 (8.8)	732 (8.6)

¹Data are means ± SD.

RGB: Right-sided gallbladder; LGB: Left-sided gallbladder; RSLT: Right-sided ligamentum teres; LT: Ligamentum teres.

Table 2 Demographics and clinical characteristics of the 36 patients with left-sided gallbladder stratified by location of ligamentum teres

Variables		RSLT (n = 25)	Typical LT (n = 11)	P value
Sex (men), n (%)	-	17 (68.0)	6 (54.5)	0.439
Age (yr)	-	61.4 ± 18.2	55.5 ± 20.8	0.401
Comorbidity, n (%)	Hepatitis B virus carrier	5 (20.0)	1 (9.1)	0.643
	Hepatitis C virus carrier	0 (0.0)	1 (9.1)	0.306
	Hepatocellular carcinoma (HCC)	2 (8.0)	2 (18.2)	0.570
	Non-HCC malignancy	13 (52.0)	5 (45.5)	0.717
	Cardiovascular disease	7 (28.0)	3 (27.3)	1.000
	Chronic kidney disease	4 (16.0)	0 (0.0)	0.290
	Diabetes mellitus	6 (24.0)	0 (0.0)	0.148
Outcomes
Major portal vein anomalies1, n (%)	Overall	20 (80.0)	2 (18.2)	0.0012
	Independent right lateral type	13 (52.0)	1 (9.1)	0.025
	Trifurcation	6 (24.0)	1 (9.1)	0.400
	Absence of R’t PV	1 (4.0)	0 (0.0)	> 0.99

¹Positive predictive value of left-sided gallbladder in portal vein anomalies = 61.1%.

²Logistic regression: Odds ratio= 18; 95% confidence interval: 2.92-110.96; P = 0.002.

LGB: Left-sided gallbladder; HCC: Hepatocellular carcinoma; RSLT: Right-sided ligamentum teres; LT: Ligamentum teres.

Table 3 Demographic and clinical characteristics of the 34 patients with right-sided ligamentum teres stratified by gallbladder location

Variables		RGB (n =9)	LGB (n = 25)	P value
Sex (men), n (%)	-	4 (44.4)	17 (68.0)	0.254
Age (yr)	-	66.9 ± 16.6	61.4 ± 18.2	0.434
Comorbidity, n (%)	Hepatitis B virus carrier	1 (11.1)	5 (20.0)	0.293
	Hepatitis C virus carrier	0 (0.0)	0 (0.0)	NA
	Hepatocellular carcinoma (HCC)	0 (0.0)	2 (8.0)	> 0.99
	Non-HCC malignancy	5 (55.6)	13 (52.0)	0.855
	Cardiovascular disease	1 (11.1)	7 (28.0)	0.403
	Chronic kidney disease	1 (16.7)	4 (16.0)	1.000
	Diabetes mellitus	3 (33.3)	6 (24.0)	0.670
Outcomes
Major PVA, n (%)	Overall	8 (88.9)	20 (80.0)	> 0.99
	Independent right lateral	7 (87.5)	13 (52.0)	0.250
	Trifurcation	1 (12.5)	6 (24.0)	0.670
	Absence of R’t PV	0 (0.0)	1 (4.0)	> 0.99

RSLT: Right-sided ligamentum teres; RGB: Right-sided gallbladder; LGB: Left-sided gallbladder; PVA: Portal venous anomalies; NA: Not available.

Table 4 Characteristics of study patients before and after propensity score analysis

		Before propensity score matching				After propensity score matching
Factors		RSLT (n = 34)	Typical LT (n = 8518)	P value	SMD1	RSLT (n = 22)	Typical LT (n = 22)	P value	SMD1
Age		62.9 ± 17.7	59.5 ± 16.2	0.2282	0.197	62.7 ± 17.1	59.9 ± 17.2	0.4113	0.156
Sex, n (%)	Men	21 (61.8)	4462 (52.4)	0.3054	0.193	11 (50)	11 (50)	1.0002	0
	Women	13 (38.2)	4056 (47.6)			11 (50)	11 (50)
GB, n (%)	LGB	25 (7.35)	28 (0.3)	< 0.0014	2.327	13 (59.1)	13 (59.1)	1.0002	0
	RGB	9 (26.5)	8490 (99.7)			9 (40.9)	9 (40.9)
Outcomes
Major PVA, n (%)						17 (77.3)	1 (4.5)	< 0.0015

¹Standardized mean difference (SMD). SMD indicate very small differences for values less than 0.10; 0.1-0.3. Small differences; 0.3-0.5, moderate differences; and values higher than 0.5, large differences.

²Student’s t test.

³Paired-t test.

⁴Chi-square test.

⁵Conditional logistic regression: Odds ratio = 16.27; 95% confidence interval: 2.25-117.53; P = 0.006.

RSLT: Right-sided ligamentum teres; LT: Ligamentum teres; RGB: Right-sided gallbladder; LGB: Left-sided gallbladder; PVA: Portal venous anomalies; SMD: Standardized mean difference; GB: Gallbladder.

Table 5 Characteristics of study patients before and after inverse probability of treatment weighting

		Before IPTW				After IPTW
Factors		RSLT (n = 34)	Typical LT (n = 8518)	P value	SMD1	RSLT (n = 34)	Typical LT (n = 34)	P value	SMD1
Age		62.9 ± 17.7	59.5 ± 16.2	0.2282	0.197	62.9 ± 17.7	62.3 ± 14.6	0.879	0.034
Sex, n (%)	Men	21 (61.8)	4462 (52.4)	0.3054	0.193	21 (61.8)	19.4 (58.1)	0.9533	0.076
	Women	13 (38.2)	4056 (47.6)			13 (38.2)	14 (41.9)
GB, n (%)	LGB	25 (7.35)	28 (0.3)	< 0.0014	2.327	25 (73.5)	24.4 (73.1)	1.0003	0.011
	RGB	9 (26.5)	8490 (99.7)			9 (26.5)	9 (26.9)
Outcomes
Major PVA, n (%)						28 (82.4)	1.6 (4.7)	< 0.0014	2.514

¹Standardized mean difference (SMD). SMD indicate very small differences for values less than 0.10; 0.1-0.3. Small differences; 0.3-0.5, moderate differences; and values higher than 0.5, large differences.

²Student’s t test.

³McNemar test.

⁴Chi-square test.

IPTW: Inverse probability of treatment weighting; RSLT: Right-sided ligamentum teres; LT: Ligamentum teres; RGB: Right-sided gallbladder; LGB: Left-sided gallbladder; PVA: Portal venous anomalies; SMD: Standardized mean difference; GB: Gallbladder.