Fig. 2.

Mechanisms of simple tools for the diagnosis of obstructive complications. Hegar dilators Nos. 5 to 7 and bougies à boule Charrière 21 to 24. a Rotation of the Hegar dilator during retraction through the urethra will show a snap phenomenon if the sling is too tight, i.e., not tension-free in patients presenting with signs of obstructive sling complications. b Retraction of the bougie à boule exerting slight pressure on the posterior urethral wall will elicit severe pain at the proximal edge of the sling in patients with a sling penetrating the urethral lumen or lying very close to the lumen