We aimed to compare the efficiency of cold knife urethrotomy and laser urethrotomy in endoscopic surgery of urethral strictures.

A total of 171 patients who underwent endoscopic surgery for urethral strictures between 2010 and 2018 were evaluated retrospectively. Since laser was not used in our clinic until 2015, the patients were treated with cold knife urethrotomy (group-1). Group-2 patients include all patients who consulted after 2015, and underwent laser urethrotomy. The patients underwent urethral surgery or urethral dilatation, under 14 years of age, had a urethral stricture longer than 2 cm, and who did not have one year regular follow-ups were excluded from the study.
A 53 patients out of the 118 patients with complete data underwent cold knife urethrotomy (group 1), and 65 patients (group 2) underwent laser urethrotomy. Both groups were compared in terms of length of the stricture, operation time, preoperative and postoperative 3rd, 6th and 12th-month Qmax values, recurrence and the presence of complications (such as bleeding, extravasation, fever etc.). The Q max values below 10 mm/s were accepted as recurrence. "SPSS 11 for Windows" statistical package program was used for statistical calculations and the data were expressed as an arithmetic average, standard deviation. Chi-square distribution test was used for the calculation of categorical variables and Mann-Whitney U test was used to compare the averages. 95% confidence interval (p <0.05) was accepted as statistically significant.

The mean age was 57.47 ± 12.57 in group 1 patients, and 59.49 ± 11.37 in group 2 patients (p=0.305). No significant difference was observed between the two groups in terms of the aetiology (traumatic, inflammatory, iatrogenic, idiopathic; p=0.696). The stricture was located in the bulbar urethra in 41 (77.4%) patients, and penile urethra in 12 (22.6%) patients in group 1; versus bulbar urethra in 57 (87.7%) patients, and penile urethra in 8 (12.3%) patients in group 2 (p=137 ). While there was no difference between the two groups for the mean stricture length (10.39 ± 3.12 mm vs 10.8 ± 3.06 mm, p=0.321), the operation time was found to be shorter in patients who underwent cold knife urethrotomy (14.01 ± 3.86 min vs 25.03 ± 4.43 min, p=0.001) (Table 1). 
In addition, while no difference was observed between the two groups for preoperative average Qmax values (p=0.921), the Q max values in the postoperative 3rd, 6th and 12th months were higher in the group that underwent laser urethrotomy (p=0.03, p=0.001, p=0.001, respectively). At the end of a one-year follow-up, recurrence was determined in 28 (52.83%) patients in group 1, and 12 (18.46%) patients in group 2 (p = 0,001). It was determined that 2 patients had recurrence in the 3rd months, 4 patients in the 6th month, 22 patients in the 1st year in group 1, versus 1 patient had recurrence in the 3rd months, 3 patients in the 6th month, and 8 patients in the 1st year in group 2 (Table 2). 
In the postoperative period, the following complications were observed as, bleeding in 10 (18.8%) patients, fever in 2 (3.7%) patients, fluid extravasation in 2 (3.7%) patients in group 1, and bleeding in 3 (4.61%) patients, fever in 7 (10.7%) patients and fluid extravasation in 1 (1.5%) patient, in group 2 (p=0.209).

Recently, we have hopes of increased success and lower recurrence compared to classical method thanks to the laser practice (Holmium, Argon, carbon dioxide, excimer, diode, KTP and Nd:YAG lasers). The widest meta-analysis conducted by Jin et al found that laser urethrotomy results were better, however, there was no statistically significant difference between laser urethrotomy and cold knife urethrotomy (1). Unfortunately, it was stated that laser urethrotomy caused more side effects than cold knife urethrotomy. With the increasing use of laser urethrotomy, the number of publications comparing the two methods has recently increased. In these publications, generally, laser urethrotomy is found to be more effective. Aboulela et al. compared the two methods in children. A significant increase in Qmax was detected better in laser urethrotomy. Additionally, the success rate in the second operation was determined to be higher in the laser urethrotomy group (2). Although the recurrence rates in the first 3 months were observed to be similar in both methods in a recent meta-analysis, the recurrence rates in the 6th and 12th months were determined to be lower in the laser urethrotomy group (3). In the current study, a significant increase in Q max values in the 3rd, 6th and 12th months in favour of laser urethrotomy was determined (p=0.03, p=0.001, p=0.001, respectively).

Our study showed that laser urethrotomy technique had lower recurrence rate and better Qmax values compared to cold knife urethrotomy at the 3rd, 6th and 12th months. None of these techniques had serious complications, and both were found to be reliable. The increase in the number of studies performed on laser urethrotomy in recent years constitutes the belief that this method can be performed more widely and it will be more preferred.

Jin T, Li H, Jiang LH, Wang L, Wang KJ. Safety and efficacy of laser and cold knife urethrotomy for urethral stricture. Chin Med J. 2010; 123: 1589–95.
Aboulela W, ElSheemy MS, Shoukry M, Shouman AM, Shoukry AI, Ghoneima W, et al. Visual internal urethrotomy for management of urethral strictures in boys: a comparison of short-term outcome of holmium laser versus cold knife. Int Urol Nephrol. 2018; 50: 605-9.
Torres Castellanos L, Moreno Bencardino MC, Bravo-Balado A, García Mayorga CA, Vargas Manrique I, Fernández N. Evaluation of the efficacy and safety of laser versus cold knife urethrotomy in the management of patients with urethral strictures: a systematic review and meta-analysis of randomized clinical trials. Urol Int. 2017; 99: 453-9.