Late biliary complications in human alveolar echinococcosis are associated with high mortality

Table 1 Comparison of patients with and without late biliary complications

	Patients with late biliary complications (n = 26)	Control group without late biliary complications (n = 32)	P1value
Male	42.30%	37.50%	NS
Year of AE diagnosis	1967-1997	1979-2003
Age at AE diagnosis, (yr)	55.5 (35.5-65)	60.0 (44.2-64.6)	NS
Previous liver surgery	13 (50)	5 (15.6)	0.009
Years between AE diagnosis and first biliary complication, (yr)	15.0 (8.3-19.0 )	NA
Age at first biliary complication, (yr)	64.5 (54.0-75.8)	NA
Deaths during follow-up until 2006	15 (57.7)	5 (15.6)	NA2
Liver related	5	1
Non-liver related	10	4
Age at death, (yr)	80.0 (67.5-81 )	78.5 (65.0-85.1)	NS
Benzimidazole treatment (total) , (yr)	13.0 (8.1-20.0)	7.2 (4.2-16.1)	0.0404
Follow-up (total) , (yr)	23.0 (13.0-25.0)	8.6 (5.1-18.8)	< 0.0001
Follow-up of survivors until study endpoint (end of 2006 or drop-out), (yr)	11	27
From AE diagnosis	- 24.0 (23.0-29.0)	7.1 (5.0-14.7)	0.0001
From biliary complication	- 9.0 (7.3-11.8)	NA
Follow-up until death, (yr)	15	5	NS
From AE diagnosis	15.0 (11.0-24.5)	21.2 (9.7-25.1 )
From biliary complication	2.0 (1.5-5.0)	NA

Data are expressed as absolute numbers (percentage) or median (quartiles). Comparison of patients with and without late biliary complications. ¹For statistical analyses Fisher’s exact test was used for gender and outcome (death); for all other comparisons the Mann-Whitney U test was employed;

²Direct comparison is not appropriate at this point since time of follow up is different for both patient groups. After adjustment for this difference in the survival analysis (compare Figure 2), no significant difference remained. AE: Alveolar echinococcosis; NA: Not applicable; NS: No significant.

Table 2 Summary of 44 late biliary symptoms and complications occurring in 26 patients and their respective outcome

Biliary complication	No. of patients	Outcome Number deaths during follow-up	Time to death of non-survivors, (yr)	Length of follow-up after BC, (yr)
Sclerosing cholangitis-like lesions (subtype2)	8 (31)	7/8 (87.5)	3 (1.5-5)	3.75 (1.75-6)
Stenosis of the common bile duct (subtype 4)	7 (27)	4/7 (57)	4 (1.75-6.75)	6 (4-10)
Late cholangitis (subtype 1)	14 (54)	5/14 (35)	2 (2.5-6)	7 (4-10.25)
Hepatolithiasis (subtype 3)	5 (19)	3/5 (60)	2 (2-3)	4 (2-6)
Secondary biliary cirrhosis(subtype 5)	7 (27)	4/7 (57)	3 (2-4.5)	6 (3-7)
Postoperative biliary stenosis after hepaticojejunostomy (subtype 7)	1 (4)	No deaths		11
Biliary fistula (subtype 8)	2 (8)	No deaths		8

Since one patient can have more than one late biliary complication, numbers do not add up to 100%. Data are expressed as absolute numbers (percentage) or median (IQR).

Table 3 Correlation and linear regression analysis for the risk of developing biliary complications

		Pearson correlation		Linear regression analysis
Variable number	Variable	Pearson correlation coefficients	P value for Pearson correlation	Unadjusted regression coefficients	P value for regression coefficients
1	Gender	0.049	NS	0.141	NS
2	Age at diagnosis of AE	-0.146	NS	Redundant	-
3	Mebendazole treatment	0.403	0.001	Redundant	-
4	Albendazole treatment	-0.351	0.003	-0.037	0.016
5	Benzimidazole treatment	0.274	0.019	0.030	0.013
6	Whether or not surgery was performed	0.370	0.02	0.354	0.031
7	Age at diagnosis of biliary complication	-0.069	NS	0.001	NS
8	Years from diagnosis of AE until endpoint (either BC or end of follow up)	0.198	NS	-0.024	NS

Pearson correlation coefficients show the interdependence between pairs of variables, positive values indicate correlation and negative values anticorrelation. Regression coefficients from a multivariate linear-regression model are shown in column 5. Redundant variables (Var2 = Var7-Var8 and Var3 = Var5-Var4) do not appear in regression coefficients. R-square of the regression model is: 0.291. P values (95%CI) for Pearson correlation and regression coefficients are also indicated.

Table 4 Previous surgery and biliary complications

	Previous surgery (n = 13)	No previous surgery (n = 13)
Late cholangitis	8	6
Sclerosing-cholangitis like lesions	2	6
Hepatolithiasis	3	2
Affection of big bile ducts	3	4
Secondary biliary cirrhosis	4	3
Postoperative biliary stenosis (after hepaticojejunostomy)	1	0
Biliary fistula	2	0

Distribution of various late biliary complications among patients with and without previous surgery. None of these differences reached statistical significance (Fisher’s exact test).