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Year : 2020  |  Volume : 33  |  Issue : 4  |  Page : 1358-1361

Holmium laser vs cold knife – direct vision internal urethrotomy in management of bulbar urethral stricture

1 Department of Urology, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2 Department of Urology, Sohag Teaching Hospital, Sohag, Egypt

Date of Submission04-Apr-2020
Date of Decision09-Jun-2020
Date of Acceptance15-Jun-2020
Date of Web Publication24-Dec-2020

Correspondence Address:
Ayman F Adli
MBBCH, Assiut 71631
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/mmj.mmj_113_20

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The aim was to compare the safety and efficacy of using Holmium: YAG laser vs the cold knife in the treatment of short-segment bulbar urethral stricture.
Male urethral stricture is a common condition in urological practice. Cold knife urethrotomy is the most appealing therapeutic method among urologists, as it is an easy and minimally invasive endoscopic procedure.
Patients and methods
This is a randomized prospective study that was done on 60 patients divided into two groups: group A included 30 patients subjected to cold knife urethrotomy (direct VIU), and group B included 30 patients subjected to HO: YAG laser urethrotomy (laser VIU).
After 6 months, the success rate was 77.8% with less than 1-cm stricture length of direct VIU cases vs 78.3% with less than 1-cm stricture length of laser VIU cases. On the contrary, it was 41.7% with stricture greater than 1 cm of direct VIU cases vs 42.9% with more than 1 cm stricture length of laser VIU cases. After 12 months, we had the same results obtained at 6 months.
Laser VIU by using Ho: YAG laser can be used as a method of treatment of this disorder. It is an effective, low-invasive technique, with results are comparable to those of cold knife (direct VIU).

Keywords: bulbar urethra, cold knife, Holmium laser, internal urethrotomy, urethral stricture

How to cite this article:
Elgharbawy MS, Adli AF, Abdallaha MM, Elserafy FA. Holmium laser vs cold knife – direct vision internal urethrotomy in management of bulbar urethral stricture. Menoufia Med J 2020;33:1358-61

How to cite this URL:
Elgharbawy MS, Adli AF, Abdallaha MM, Elserafy FA. Holmium laser vs cold knife – direct vision internal urethrotomy in management of bulbar urethral stricture. Menoufia Med J [serial online] 2020 [cited 2021 Apr 18];33:1358-61. Available from: http://www.mmj.eg.net/text.asp?2020/33/4/1358/304475

  Introduction Top

Urethral stricture refers to deposition of fibrotic tissue that narrows urethral lumen and renders the normal compliant lumen inelastic[1]. Urethral stricture is a common problem in urology; the incidence of urethral stricture has been estimated as 200–1200 cases per 100 000 individuals, with the incidence rising sharply in people aged greater than or equal to 55 years in the USA[2]. In the UK, 12 000 patients need surgical intervention per year[3]. The prevalence is more in the developing worlds than the developed ones[4]. The traditional therapeutic methods are urethral dilatation and cold knife urethrotomy, which is a minimally invasive endoscopic procedure[5]. Laser urethrotomy is used in the hope of reducing the high recurrence rate of the cold knife by both cutting and vaporizing the scar tissue thought to be responsible for these recurrences[6],[7]. Good results are known to be obtained by using open urethroplasty. In many studies, the effectiveness is ∼93%, and other studies had effectiveness of approximately 92 and 85%[8],[9],[10]. End-to-end urethral anastomosis has a high success rate, and it is considered as the gold standard by most of the researchers despite its morbidity. Endoscopic methods are minimally invasive, safe for patients with little complications, and reduce the period of hospitalization. The endoscopic Ho: YAG laser incision appears to be less traumatic and less morbid, with a high success rate[11],[12]. The major advantages of using a laser include less blood loss and a shorter hospital stay, which is the same as endoscopic cold knife urethrotomy[13]. Bülow and colleagues performed the first laser application for the treatment of urethral stricture using an Nd: YAG laser with the idea of reduced scar formation[14].

This study aims to compare the safety and efficacy of Ho: YAG laser vs the cold knife in the treatment of short-segment bulbar urethral stricture.

  Patients and Methods Top

A total of 60 patients were included in this random prospective controlled study at Menoufia University Hospital from April 2016 to September 2018 by using retrograde endoscopic Ho: YAG laser (sphinx, Holmium laser; Lisa Laser Co., Katlenburg-Lindau, Germany) and cold knife (Karl-Storz, Tuttlingen, Germany). They were divided into two groups: group A included 30 patients (18 cases with stricture length <1 cm and 12 >1 cm) subjected to cold knife urethrotomy and group B included 30 patients (23 cases with stricture length <1 cm and 7 >1 cm) subjected to HO: YAG laser urethrotomy. Inclusion criteria included fresh, short, and single stricture, whereas exclusion criteria included long stricture segments more than 1.5 cm, urethral stricture following rupture urethra, recurrent cases, and complicated cases. The diagnosis was based on history (obstructive symptoms), uroflowmetry, and retrograde urethrography [Figure 1]. The length of the urethral stricture ranged from 0.5 to 1.5 cm. The length of stricture was measured on ascending and micturating cystogram and confirmed by the cystoscope. Postoperative follow-up was done by uroflowmetry as shown in [Figure 2] after 2 weeks and retrograde urethrography after 6 and 12 months [Figure 3]. According to the American Society of Anesthesiologists score (ASA), cases of direct VIU were divided into 18 cases with score ASA I, 10 cases of ASA II, and two cases of ASA III score, and laser VIU cases were 15 cases of ASA I, 12 cases were ASA II, and three cases of ASA III.
Figure 1: Ascending urethrocystogram showing bulbar urethral stricture.

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Figure 2: Uroflowmetry, preoperative flowmetry shows the characteristic obstructive curve with Qmax less than 15 ml/s.

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Figure 3: Ascending urethrocystogram showing bulbar urethral stricture.

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Ethical considerations

The study was approved by the Research Ethics Committee, Menoufia University, and written informed consent was signed by every patient for laboratory investigations and instrument used in the study such as retrograde urethrography (1000 ml; Philips, Hamburg, Germany) and the cystoscope (Karl-Storz).


For cold knife (direct VIU) group, a cystoscope (22 Fr) was inserted. Once the position of the guidewire in the urinary bladder was maintained, the cystoscope was withdrawn, and the cold knife urethrotomy was performed using 21-Fr sheath and 0° telescope. The stricture was incised at the 12 o' clock position until it allowed proceeding of the scope into the bladder. On withdrawing the scope, the stricture site was inspected for any residual stricture. An 18-Fr silicone catheter was fixed and kept for 7 days and then removed. In the holmium laser (laser VIU) group, a 0.365-mm fiber with 1 J pulse energy, 10 Hz frequency, and 10-W total power were set up, respectively. Stricture was incised at the 12 o'clock position till fresh edges appeared. Then cystoscope was moved till the bladder and pulled back through the lesion where the stricture was dilated. Finally, 18-Fr silicone catheters were indwelled and kept for 7 days.

Statistical method

Data entry and data analysis were done using SPSS version 19 (Statistical Package for the Social Sciences; IBM Collaboration and Deployment Service, Chicago, Illinois, USA). Data were presented as a number, percentage, mean, and SD. χ2 test and Fisher exact test were used to compare qualitative variables. Independent samples t-test was used to compare between two quantitative variables. A paired samples t-test was done to compare quantitative data between preoperative and postoperative quantitative variables. P value considered statistically significant when less than 0.05.

  Results Top

A total of 60 male patients with bulbar urethral stricture fulfilling the inclusion criteria in the absence of the exclusion criteria were scheduled for urethrotomy by either laser or cold knife [Diagram 1]. The mean postoperative Qmax at 2 weeks was 22.18 ± 6.14 ml/s (range: 10.7–30.4) for direct VIU cases and for laser cases was 24.59 ± 4.88 ml/s (range: 16.8–30.4). This difference was statistically insignificant (P = 0.104) [Table 1]. According to length of stricture, after 6 months, no recurrence occurred in 14 (77.8%) of 18 cases with less than 1-cm stricture length of direct VIU cases vs 18 of 23 (78.3%) cases with less than 1 cm stricture length of laser VIU cases, and this difference was not statistically significant (P = 0.970). Follow-up of the same patients at 12 months revealed the same results. On evaluating results obtained from urethral strictures more than 1 cm after 6 months, no recurrence occurred in 5 (41.7%) of 12 cases in direct VIU cases vs 3 of 7 cases (42.9%) of laser VIU cases, and this difference was not statistically significant (P = 0.960). Follow-up of the same patients at 12 months revealed the same results. This study showed better results in short strictures less than 1 cm than in long strictures more than 1 cm [Table 2]. According to the Modified Clavien System of surgical complications, at direct VIU group, one case of ASA II was complicated by postoperative edema, which was managed conservatively, and two cases of ASA III were complicated by postoperative bleeding and managed by blood transfusion. For cases of laser VIU group, two cases of ASA I were complicated by postoperative edema and also managed conservatively, whereas no case of ASA III had any complication, which supports the advantage of using laser VIU over direct VIU in comorbidity cases, especially cases with coagulopathy and those who are on anticoagulant treatment [Table 3].

Table 1: Postoperative flowmetry of the studied groups

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Table 2: Comparison between results according to length of stricture

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Table 3: Comparison between direct VIU and laser VIU according to modified Clavien system

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  Discussion Top

Many types of lasers have been used for the treatment of urethral stricture disease include carbon dioxide (CO2), argon, potassium titanyl phosphate: (KTP), neodymium: Yttrium-Aluminum-Garnet (Nd: YAG), Holmium: Yttrium-Aluminum-Garnet (Ho: YAG), and excimer lasers[15]. In our study, we used Ho: YAG laser. Our mean operative time was longer than Atak and colleagues. It was longer in the first cases done and then decreased gradually. All previous studies observed increasing postoperative Qmax in both groups in short- and long follow-up, with no significant difference between both groups. The study by Dutkiewicz and colleagues concluded that the therapy was of equal result for both groups at 1 year. In the study by Kumar and colleagues, the Qmax increased in both groups postoperative, with no significant difference in Qmax values for both groups in short- and long-term follow-up at day 1, 15, 30, and 180 of the study. At 6 months, recurrence in the study by Jhanwar and colleagues was seen in four (7.27%) patients in group A and four (7.69%) in group B. The study by Kumar and colleagues observed no recurrence in group A and six (13.3%) cases in group B. In our study, recurrence was 11 (36.7%) cases in group A and nine (30%) in group B. The difference between results may be attributed to the optimal laser power applied, selection of the appropriate laser fiber, age of patients, duration of catheter fixation, and the follow-up period[2],[16],[17],[18].

  Conclusion Top

Ho: YAG laser urethrotomy is a safe and effective minimal invasive therapeutic modality for treatment of short-segment bulbar urethral stricture with the same results of the cold knife. However, longer follow-up studies are recommended. The laser urethrotomy might at least be an alternative to urethroplasty in patients with high comorbidity who are not suitable for open reconstruction.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Hampson LA, McAninch JW, Breyer BN. Male urethral strictures and their management. Nat Rev Urol 2014; 11:43–50.  Back to cited text no. 1
Santucci RA, Joyce GF, Wise M. Male urethral stricture disease. J Urol 2007; 177:1667–1674.  Back to cited text no. 2
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Heyns CF, Steenkamp JW, De Kock ML, Whitaker P. Treatment of male urethral strictures: is repeated dilation or internal urethrotomy useful? J Urol 1998; 160:356–358.  Back to cited text no. 5
Smith JAJr, Dixon JA. Neodymium: YAG laser treatment of benign urethral strictures. J Urol 1984; 131:1080–1081.  Back to cited text no. 6
Rothauge CF. Urethroscopic recanalization of urethral stenosis using argon laser. Urology 1980; 16:158–161.  Back to cited text no. 7
Barbagli G, Palminteri E, Lazzeri M, Guazzoni G, Turini D. Long-term outcome of urethroplasty after failed urethrotomy vs primary repair. J Urol 2001; 165(6 Pt 1):1918–1919.  Back to cited text no. 8
Micheli E, Ranieri A, Peracchia G, Lembo A. End-to-end urethroplasty: long-term results. BJU Int 2002; 90:68–71.  Back to cited text no. 9
Palminteri E, Lazzeri M, Guazzoni G, Turini D, Barbagli G. New 2-stage buccal mucosal graft urethroplasty. J Urol 2002; 167:130–132.  Back to cited text no. 10
Dogra PN, Ansari MS, Gupta NP, Tandon S. Holmium laser core-through urethrotomy for traumatic obliterative strictures of urethra: initial experience. Urology 2004; 64:232–235. discussion 5–6.  Back to cited text no. 11
Hossain AZ, Khan SA, Hossain S, Salam MA. Holmium laser urethrotomy for urethral stricture. Bangladesh Med Res Counc Bull 2004; 30:78–80.  Back to cited text no. 12
Noe HN. Endoscopic management of urethral strictures in children. J Urol 1981; 125:712–714.  Back to cited text no. 13
Fallah Karkan M, Razzaghi MR, Karami H, Ghiasy S, Tayyebiazar A, Javanmard B. Experience of 138 transurethral urethrotomy with holmium: YAG laser. J Lasers Med Sci 2019; 10:104–107.  Back to cited text no. 14
Gibod LB, Le portz B. Endoscopic urethrotomy: does it live up to its promises? J Urol 1982; 127:433–435.  Back to cited text no. 15
Atak M, Tokgoz H, Akduman B, Erol B, Donmez I, Hanci V, et al. Low-power holmium: YAG laser urethrotomy for urethral stricture disease: comparison of outcomes with the cold-knife technique. Kaohsiung J Med Sci 2011; 27:503–507.  Back to cited text no. 16
Dutkiewicz SA, Wroblewski M. Comparison of treatment results between holmium laser endourethrotomy and optical internal urethrotomy for urethral stricture. Int Urol Nephrol 2012; 44:717–724.  Back to cited text no. 17
Jhanwar A, Kumar M, Sankhwar SN, Prakash G. Holmium laser vs. conventional (cold knife) direct visual internal urethrotomy for short-segment bulbar urethral stricture: outcome analysis. Can Urol Assoc J 2016; 10:E161–E164.  Back to cited text no. 18


  [Figure 1], [Figure 2], [Figure 3]

  [Table 1], [Table 2], [Table 3]


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