Table 1 Preoperative patient characteristics

Age (days)

54.4 ± 22.6

52.5 ± 27.6

.35

Sex (males)

22

28

.69

Weight (kg)

3.9 ± 0.6

4.1 ± 0.5

.84

Pyloric muscle thickness (mm)^a

4.6 ± 1.0

4.2 ± 0.8

.25

Pylorus length (mm)^a

20.8 ± 2.1

21.3 ± 2.3

.72

Chloride

103.1 ± 5.4

102.8 ± 7.1

.86

Bicarbonate

27.1 ± 4.3

26.7 ± 5.4

.73

Sodium

137.6 ± 3.2

139.1 ± 4.3

.56

Duration of symptoms (days)

10 (4–40)

9 (7–35)

.23