Parameter

Outcome

Total

p-value (<0.05)

Failed

Successful

Age (yrs)

65 - 69

1

19

20

0.446

70 - 74

2

12

14

75+

2

7

9

Number of procedures

1

2

34

36

0.004849

2

3

4

7

Number of strictures

1

3

33

36

0.126

2

2

5

7