Diagnostic value of drain amylase for detecting intrathoracic leakage after esophagectomy

Table 1 Patient characteristics

	Anastomotic leakage (n = 15)	No anastomotic leakage (n = 74)	P value
Sex			1.001
Male	12 (80)	59 (80)
Female	3 (20)	15 (20)
Age	71 (64-76)	65 (57-69)	0.012
Steroid use	1 (7)	2 (3)	0.431
Comorbidity	11 (73)	51 (69)	1.001
Cardiac	2 (13)	18 (24)	0.511
Vascular	4 (27)	34 (46)	0.251
Diabetes	4 (27)	18 (24)	1.001
Pulmonary	5 (33)	17 (23)	0.403
Renal	0 (0)	1 (1)	1.001
BMI > 30 kg/m2	3 (20)	13 (18)	0.731
ASA score			0.462
I	1 (7)	5 (7)
II	11 (73)	46 (62)
III	3 (20)	23 (31)
Neoadjuvant therapy			0.762
None	0 (0)	6 (8)
Chemotherapy	0 (0)	4 (5)
Chemoradiotherapy	15 (100)	65 (87)
Jejunostomy	6 (40)	24 (32)	0.573
Start of oral feeding (POD)	1 (1-1)	1 (1-1)	0.462

¹Fisher’s exact test;

²Mann Whitney U test;

³χ² test. Values are presented as absolute numbers (percentage) or medians (lower quartile-upper quartile). POD: Postoperative day.

Table 2 Intrathoracic anastomotic leakage n (%)

	n = 15/89 (16.9)
Intervention type
Antibiotics and NPO	8 (9.0)
Endoscopic stent	3 (3.4)
Surgical reintervention	4 (4.5)
According to Clavien-Dindo
Grade II	0 (0)
Grade IIIa	9 (10.1)
Grade IIIb	0 (0)
Grade IVa	6 (6.7)

NPO: Nil-by-mouth.

Table 3 Diagnostic value of drain amylase

Time of measurement	AUC	Cut-off (IU/L)	Sensitivity	Specificity	RR
Per postoperative day
POD 1	0.672	350	21.4	95.6	3.5a
POD 2	0.676	200	26.4	95.7	4.0a
POD 3	0.685	160	35.7	94.0	4.4a
Any POD
Same cut-off as Machens et al[17]		600	53.3	97.3	9.0a
Most accurate in our cohort		1900	53.3	98.7	10.2a

Values are presented as international units per liter or as percentages.

^aP < 0.05 vs control. POD: Postoperative day; AUC: Area under the curve; RR: Risk ratio.