Dilatation

Sallami S, Mouine Y, Rhouma SB, Cherif K, Dahmani A, Horchani A (2011)
Clean Intermittent Catheterization Following Urethral Stricture Surgery Using a Low Friction Catheter Versus Conventional Plastic Catheter: A Prospective, Randomized Trial 
RCT on the prevention and/or treatment of recurrent strictures after endoscopic urethrotomy using LoFric and plastic catheters. Study was favorable for Lofric.
2 year follow-up on 31 LoFric users and 28 PVC-users.

Lauritzen M, Greis G, Sandberg A, Wedren H, Ojdeby G, Henningsohn L (2009)
Intermittent self-dilatation after internal urethrotomy for primary urethral strictures: a case-control study 
Evidence of the preventative effects of intermittent self-dilatation (ISD) on stricture recurrence. For example, stricture recurrence was 8% among those who practiced ISD with hydrophilic catheters and 32% in the control. The median time to first recurrence was 2 years for the ISD group and 6 months for the control.
3-6 year study on 55 LoFric and other hydrophilic catheter- users and 162 control patients.

Harriss DR, Beckingham IJ, Lemberger RJ, Lawrence WT (1994)
Long-term results of intermittent low-friction self-catheterization in patients with recurrent urethral strictures 
Evidence that Lofric is a safe and effective way to prevent stricture recurrence in the long term (>12 months)
6-36 months study on 101 LoFric users.

Kjaergaard B, Walter S, Bartholin J, Andersen JT, Nohr S, Beck H, Jensen BN, Lokdam A, Glavind K (1994)
Prevention of urethral stricture recurrence using clean intermittent self-catheterization
Provides evidence for the use of LoFric to effectively reduce the frequency of recurrent urethral strictures. For example, 68% of patients not treated with intermittent catheterization experience recurrent strictures during the first year after urethrotomy compared to 19% in the LoFric group.
1-4 year study on 31 LoFric users and 24 control patients.

Bodker A, Ostri P, Rye-Andersen J, Edvardsen L, Struckmann J (1992)
Treatment of recurrent urethral stricture by internal urethrotomy and intermittent self-catheterization: a controlled study of a new therapy 
No recurrent strictures in patients actively practicing intermittent catheterization. Study suggests prolonged or permanent use of intermittent catheterization in order to prevent recurrence of urethral strictures (refers to Lawrence et al, 1991 and Zambon et al, 1990 on the use of LoFric).
12 month follow-up on 23 patients on intermittent catheterization with LoFric and 28 control patients.

Robertson GS, Everitt N, Lamprecht JR, Brett M, Flynn JT (1991)
Treatment of recurrent urethral strictures using clean intermittent self-catheterisation
Evidence on LoFric use to treat and prevent recurrent urethral strictures.
6-month study on 65 patients with LoFric.

Lawrence WT, MacDonagh RP (1988)
Treatment of urethral stricture disease by internal urethrotomy followed by intermittent 'low-friction' self-catheterization: preliminary communication 
Study shows that postoperative urine flow-rates can be maintained if 'low-friction' catheterization is adopted. Study on LoFric, Preliminary results of Harriss et al, 1994.