ORIGINAL RESEARCH  
Holmium laser vs. conventional (cold knife) direct visual internal  
urethrotomy for short-segment bulbar urethral stricture:  
Outcome analysis  
Ankur Jhanwar, MD; Manoj Kumar, MD; Satya Narayan Sankhwar, MD; Gaurav Prakash, MD  
King George’s Medical University, Lucknow, India  
Cite as: Can Urol Assoc J 2016;10(5-6):E161-4. http://dx.doi.org/10.5489/cuaj.3382  
Published online May 12, 2016.  
The three most commonly performed procedures for urethral  
stricture disease are urethral dilatation, optical urethrotomy,  
and urethroplasty.  
Abstract  
We are curently in an era focused on minimally inva-  
1
,2  
sive endoscopic procedures; however, urethral stricture  
is one of the rare medical issues for which the success rate  
of open reconstructive urethroplasty is far better than more  
minimally invasive alternatives.  
Introduction: Our goal was to analyze the outcome between hol-  
mium laser and cold knife direct visual internal urethrotomy (DVIU)  
for short-segment bulbar urethral stricture.  
Methods: We conducted a prospective study comprised of 112  
male patients seen from June 2013 to December 2014. Inclusion  
criterion was short-segment bulbar urethral stricture (1.5cm).  
Exclusion criteria were prior intervention/urethroplasty, pan-anter-  
ior urethral strictures, posterior stenosis, urinary tract infection,  
and those who lost to followup. Patients were divided into two  
groups; Group A (n=58) included cold knife DVIU and group B  
Cold knife optical internal urethrotomy was popularized  
after the work of Sachse in 1974. Since then, several other  
3
endoscopic alternatives have been included in the urological  
armamentarium for the treatment of urethral stricture disease.  
Holmium laser was one of them, introduced for the treatment  
of urethral stricture disease in the early 90s. Holmium YAG  
laser works based on vaporization at a wavelength of 2140  
nm and its depth of penetration is approximately 0.5mm.  
Other lasers used for urethral stricture disease include car-  
bon dioxide, Nd:YAG, KTP, argon, and excimer lasers, but  
superiority of one laser over the other has not been mentioned  
(
n=54) included holmium laser endourethrotomy patients. Patient  
followup included uroflowmetry at postoperative Day 3, as well  
as at three months and six months.  
Results: Baseline demographics were comparable in both groups.  
A total of 107 patients met the inclusion criteria and five patients  
were excluded due to inadequate followup. Mean stricture length  
was 1.31 ± 0.252 cm (p=0.53) and 1.34 ± 0.251 cm in Groups A  
and B, respectively. Mean operating time in Group A was 16.3 ±  
4,5  
in literature. Urethrotomy has been performed either under  
general or regional anaesthesia. Some authors reported excel-  
6,7  
lent results under local anaesthesia.  
1
.78 min and in Group B was 20.96 ± 2.23 min (p=0.0001). Five  
patients in Group A had bleeding after the procedure that was  
managed conservatively by applying perineal compression. Three  
patients in Group B had fluid extravasation postoperatively. Qmax  
Methods  
(
ml/s) was found to be statistically insignificant between the two  
This prospective study — conducted after obtaining ethical  
review board committee approval and an informed written con-  
sent from all included patients — looked at patients in the urol-  
ogy department of a tertiary care teaching institute in Northern  
India from June 2013 to December 2014. A total of 107 patients  
of aged 1764 years met the inclusion criteria of having short-  
segment bulbar urethral stricture (1.5cm), evident by symp-  
toms of weak urinary stream and confirmation on radiological  
studies (i.e., retrograde urethrography [RGU] and micturating  
cystourethrography [MCU]). Exclusion criteria were patients  
with multiple strictures, pan-anterior urethral strictures, poster-  
ior stenosis, failed prior intervention, lichen sclerosis changes,  
urinary tract infection, and those lost to followup.  
groups at all followups.  
Conclusions: Both holmium laser and cold knife urethrotomy are  
safe and equally effective in treating short-segment bulbar urethral  
strictures in terms of outcome and complication rate. However,  
holmium laser requires more expertise and is a costly alternative.  
Introduction  
Urethral stricture is one of the oldest known urological prob-  
lems and it continues to be common and often challenging.  
Multiple treatment modalities have evolved over the years.  
CUAJ • May-June 2016 • Volume 10, Issues 5-6  
2016 Canadian Urological Association  
E161  
©
Jhanwar et al.  
Prior to intervention patients underwent complete physic-  
al examination, urine routine with culture and sensitivity,  
uroflowmetry, and blood investigation. The site and size  
of urethral stricture was noted. Appropriate antibiotic was  
administered pre- and post-intervention.  
Per urethral catheter removal and voiding trial was given  
at postoperative Day 3 in both groups.  
Statistical analysis  
Patients were allocated into either Group A or Group B  
in a 1:1 ratio. Group A consisted of those who underwent  
cold knife (Sachse) procedure and Group B of those who  
underwent holmium laser internal urethrotomy. Patients  
were followed with uroflowmetry (as there was no uniformly  
accepted method of followup after DVIU) and any com-  
plaints noted at postoperative Day 3, as well as after three  
and six months. The Visual Analogue Scale score (VAS) was  
taken in both groups at three, six, 12, and 24 hours pos -  
toperatively. Our protocol for postoperative analgesics was  
patients demand or VAS >5. Operating time was calculated  
from insertion of cystoscope into meatus to the removal of  
urethrotome or laser fibre with the cystoscope out of meatus.  
The results were presented in mean ± standard deviation  
(SD) and percentages. The unpaired t-test was used to  
compare two independent means. Paired t-test was used  
to compare the variables in preoperative and postopera-  
tive periods. A p value <0.05 was considered statistically  
significant. All the analysis was carried out using SPSS 16.0  
versions (Chicago, Inc., U.S.).  
Results  
Baseline demographics were comparable in both groups  
(Table 1). Data from 107 patients were analyzed. Five  
patients were excluded due to inadequate followup. The  
mean + SD age in Groups A and B was 39.38 ± 13.4 and  
38.13 ± 12.3 years, respectively (p=0.61). The mean ± SD  
operating time in Group A was 16.3 ± 1.78 minutes, while  
in Group B it was 20.96 ± 2.23 minutes (p=0.0001). The  
mean length of stricture in Group A was 1.31 ± 0.252 cm  
and in Group B was 1.34 ± 0.251cm (p=0.53).The mean  
VAS (pain score) in Group A was 4.1 ± 1.68 and in Group  
B was 3.9 ± 1.59. The duration of per urethral catheteriza-  
tion was 72 hours in both groups. Preoperative Qmax (ml/s)  
in Group A was 5.3 ± 1.98 and in Group B was 5.8 ± 2.1  
(p=0.207). The mean Qmax (ml/s) on postopertive Day 3,  
as well as at three months and six months in Group A was  
21.4 ± 2.75, 23.4 ± 2.71, and 23.7 ± 2.74, respectively.  
The mean Qmax (ml/s) on postopertive Day 3, as well as at  
Technique  
Both the procedures were done under local anaesthesia  
using mixture of 20 ml of 2% lignocaine jelly mixed with  
2
ml of 1% lignocaine solution, pushed slowly into the  
urethral lumen with the help of syringe and left for 57 mins.  
Cold knife  
In lithotomy position, a cystoscopic-assisted guidewire was  
negotiated beyond the stricture site. Once the position of the  
guidewire in the urinary bladder was confirmed, the cysto-  
scope was withdrawn and the Sachse cold knife urethrotome,  
using 21 Fr sheath and 0 degree telescope, advanced into the  
urethra. The stricture was incised at the 12 o’clock position  
Table 1. Baseline demographics, pre- and postoperative  
data  
(
single or multiple times until it adequately opened up and  
allowed negotiation of the scope into the bladder). While  
withdrawing the scope, the stricture site was inspected; if  
there was some fibrosis remaining, then it was incised. A  
Foley catheter (14 Fr) was then placed per urethraly.  
Cold knife  
DVIU  
Holmium  
laser  
Parameter  
p value  
Age  
39.38 ± 13.4 38.13 ± 12.3  
1.31 ± 0.252 1.34 ± 0.251  
0.61  
0.53  
Mean length of stricture  
Mean operating time  
Preoperative Qmax (ml/s)  
16.3 ± 1.78  
5.3 ± 1.98  
20.96 ± 2.23  
5.8 ± 2.1  
0.0001  
0.207  
The holmium laser  
Postoperative Qmax (ml/s)  
At Day 3  
At 3 months  
Once the stricture site was located, the holmium laser fibre  
21.4 ± 2.75  
23.4 ± 2.71  
23.7 ± 2.74  
21.7 ± 2.73  
23.6 ± 2.72  
23.8 ± 2.78  
0.569  
0.703  
0.851  
(
365 µm) was introduced through a side channel of 17  
Fr sheath and 0 degree scope. The holmium laser (Versa  
PowerSuite) with power settings (0.61.2 Joules, 612  
Watts) was used. To avoid thermal injury, the fibre was  
placed a few mm away from the scarred tissue. The stricture  
was incised at the 12 o’clock position and once the scope  
was negotiated beyond the stricture and up to the bladder,  
the scope was withdrawn slowly and a 14 Fr foley catheter  
was inserted per urethrally.  
At 6 months  
Complications  
Bleeding  
Fever  
12.7%  
9.6%  
5
0
2
0
2
3
0.764  
Fluid extravasation  
Mean VAS pain score  
4.1 ± 1.68  
3.9 ± 1.59  
0.51  
1
Number of patients  
require reintervention  
4
(7.27%)  
4 (7.69%)  
DVIU: direct visual internal urethrotomy; VAS: Visual Analogue Scale.  
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CUAJ • May-June 2016 • Volume 10, Issues 5-6  
Holmium laser vs. conventional urethrotomy for urethral stricture  
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2
1
1
5
0
5
0
5
0
impact on outcome. Albers et al reported that urethral cath-  
eterization left for 3 days following DVIU is associated with  
lower recurrence rate compared with longer duration (34%  
1
2
vs. 43%). Dutkiewicz et al reported increased chance of  
Cold knife  
urinary tract infection following prolonged catheterization.13  
Holmium laser  
In their studies, Heyns et al and Steenkamp et al reported  
1
4,15  
1
4 days of catheterization following urethrotomy.  
No major complications occurred in our study. Five  
patients (9.1%) in Group A had bleeding, two patients in  
each group had fever, and three patients (5.7%) in Group B  
had fluid extravasation. All were managed conservatively.  
No patient in our study had post-procedural incontinence  
or impotence.  
Preoperative Postoperative At 3 months At 6 months  
Day 3  
Fig. 1. Qmax (ml/s) at followup between two modalities.  
As the outcome criteria is not standardized following  
DVIU, we followed our patients with uroflowmetry (Qmax  
ml/s). In this study, we did not observe any statistically signifi-  
cant difference in followup Qmax between the two groups.  
Hussain et al reported that good results are achieved if  
post-procedure Qmax is >15ml/s and there is no need for  
three months and six months in Group B was 21.7 ± 2.73,  
3.6 ± 2.72, and 23.8 ± 2.78, respectively (Fig. 1).  
2
Discussion  
16  
Urethral stricture is the narrowing of urethral lumen due to  
fibrosis secondary to inflammation or trauma. Different treat-  
ment modalities with variable results are available. The one  
that is most appealing to urologists and patients is DVIU, as  
it is a minimally invasive, outpatient, endoscopic procedure.  
DVIU as a surgical treatment for urethral stricture was  
popularized after the initial report of Sachse in 1974.3,8 Since  
any other intervention. In this study, four patients in Group  
A required one more urethrotomy, two at three-month and  
two others at six-month followups. Similarly, four patients in  
Group B required another intervention, one at three-month  
and three at six-month followups. In all eight patients, Qmax  
was <10 ml/s, which was considered failure according to  
our protocol. The recurrence in Group A might have been  
due to inadequate division of fibrous tissue leading to non-  
separation of scarred tissue and, subsequently, no healing by  
secondary intention. The recurrence in Group B might have  
been due to inadequate cutting of scarred tissue, as there  
is lack of sense of depth perception with holmium laser.  
In our study, clean intermittent catheterization (CIC) was  
advised for all patients following their procedure. Our proto-  
col for CIC was once-daily for a week, then twice-weekly for  
three weeks, then once-weekly for three months. Surprisingly,  
no patient found difficulty in doing CIC. The theory behind  
CIC following DVIU is that the process of self-catheterizsation  
prevents the scar from contracting while it matures. Lawrence  
et al conducted a study on 42 patients and demonstrated  
excellent results for postoperative CIC for three months.17  
Kjaeergard et al and Harris et alalso observed lower recur-  
1984, different lasers have been introduced in the stricture  
treatment armamentarium. No currently available data  
report superiority of one laser over another. The advantage  
of Ho:YAG laser is its coagulation ability and shallow absorp-  
tion (0.5 mm); it is presumed to reduce scar tissue formation.  
In their studies, Steenkamp et al (1997), Choong et al  
(
1997), and Munks et al (2010) reported that the procedure  
of internal urethrotomy is very well-tolerated by the patient  
under local anesthesia. Similarly, in this study we also use  
local anesthesia and observed that patients tolerate the pro-  
cedure well.  
In their study of 51 male patients with single, iatrogenic  
stricture, Atak et al observed shorter operative time in laser-  
treated patients (n=21, 16.4 ± 8.04 minutes) vs. cold knife-  
9
treated patients (n=30, 23.8 ± 5.47 minutes). Kamal reported  
10  
18,19  
mean operative time of 22.3 minutes using a diode laser.  
rence rate in those who were on CIC.  
In our study, mean operative time for the cold knife group  
was 16.3 ± 1.78 minutes, which is shorter than in the study  
done by Atak et al (23.8 ± 5.47 minutes) and longer than the  
In our study, we did not observe any statistically signifi-  
cant difference between the recurrence rates in both group.  
Four patients had recurrence in each group. This result may  
be due to short-term followup and strict inclusion criteria,  
as it may be different for long-term followup; other seg -  
ments may have different recurrence rates, which was not  
analyzed in this study.  
9
,11  
study by Jain et al (7.44 minutes).  
The mean operative  
time in the holmium laser group was 20.96 ± 2.23 minutes  
in our study, which is comparable to the study done by Jain  
1
1
et al (19.8 minutes). The VAS score in Groups A and B was  
4
.1 ± 1.68 and 3.9 ± 1.59, respectively.  
In our study, catheter removal and voiding trial was given  
Jin et al did a meta-analysis including 3230 cases from  
2
0
44 articles. They reported a better success rate with hol-  
mium laser urethrotomy compared to cold knife technique  
(74.9% vs. 68.5%).  
on Day 3, as there is no convincing evidence in the literature  
that increasing the duration of catheterization has a positive  
CUAJ • May-June 2016 • Volume 10, Issues 5-6  
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Jhanwar et al.  
7
.
Ather MH, Zehri AA, Soomro K, et al. The saꢀety and eꢀfcacy oꢀ optical urethrotomy using a spongiosum  
block with sedation: A comparative nonrandomized study. J Urol 2009;181:2134-8. http://dx.doi.  
org/10.1016/j.juro.2009.01.017  
The limitations of our study were selection of only short-  
segment bulbar urethral stricture and short followup.  
8
9
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.
Sachse H. Die transurethrale scharꢀe Schlitzung der Harnrohrenstriktur unter Sicht. Munsch Med Wschr  
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974;116: 2147.  
Conclusion  
Atak M, Tokgoz H, Akduman B, et al. Lowpower holmium: YAG laser urethrotomy ꢀor urethral stricture  
disease: Comparison oꢀ outcomes with the coldkniꢀe technique. Kaohsiung J Med Sci 2011;27:503-7.  
http://dx.doi.org/10.1016/j.kjms.2011.06.013  
Both conventional (cold knife) and holmium laser urethrot-  
omy are equally effective in terms of outcome and safety for  
short-segment bulbar urethral stricture. The holmium laser  
offers a significant advantage with its coagulation ability.  
However, use of holmium laser requires more expertise and  
its availability is a limitation. As urethral stricture may recur,  
further long-term comparative studies comparing these two  
modalities are required.  
1
0. Kamal BA. The use oꢀ the diode laser ꢀor treating urethral strictures. BJU Int 2002;87:831-3. http://  
dx.doi.org/10.1046/j.1464-410x.2001.02183.x  
11. Jain SK, Kaza RC, Singh BK. Evaluation oꢀ holmium laser versus cold kniꢀe in optical internal urethrot-  
omy ꢀor the management oꢀ short segment urethral stricture. Urol Ann 2014;6:328-33. http://dx.doi.  
org/10.4103/0974-7796.140997  
1
2. Albers P, Fichtner J, Bruhl P, et al. Long-term results oꢀ internal urethrotomy. J Urol 1996;156:1611-4.  
http://dx.doi.org/10.1016/S0022-5347(01)65461-2  
13. Dutkiewicz SA, Wroblewski M. Comparison oꢀ treatment results between holmium laser endourethrotomy  
and optical internal urethrotomy ꢀor urethral stricture. Int Urol Nephrol 2012;44:717-24. http://dx.doi.  
org/10.1007/s11255-011-0094-8  
Competing interests: The authors declare no competing fnancial or personal interests.  
1
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5. Steenkamp JW, Heyns CF, de Kock MI. Internal urethrotomy versus dilatation as treatment ꢀor male urethral  
strictures.A prospective randomized comparison. J Urol 1997;157:98-101. http://dx.doi.org/10.1016/  
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This paper has been peer-reviewed.  
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Correspondence: Dr. Ankur Jhanwar, King George’s Medical University, Lucknow, India ;  
drankurstanley01@gmail.com  
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