The treatment for stricture and urethral stone is a complicated and acute issue in urologic surgery. A combination of urethral stricture with the urethral stone is a rear event. Urethral stones are observed in not more than 0.3% of all cases of urinary stone disease [1]. Stones were localized in the posterior urethra in around 88% of cases [2].

As a rule, urethral stones result from urine stagnation in the dilated part of the urethra that is proximal to the area of stricture. At the same time, the formation of a stone can be associated with urethral diverticulum, urethrocele, or the growth of hair after the previous urethroplasty with a skin flap [3]. Besides, a combination of urine stagnation and such factors as alkalinuria and urinary tract infection (UTI) play an important role in the process of lithiasis. In particular, the process of lithiasis is greatly affected by the factors associated with pelvic bone fractures and long-term complete bed rest in patients with traumatic urethral strictures. There are data that the development of urolithiasis in patients with urethral stricture directly depends on the disease duration and the number of underwent operations [4].

The treatment of urethral stones can include different surgical interventions such as stone extraction with forceps or baskets, extracorporeal shock wave lithotripsy, transurethral contact ultrasonic, laser, and pneumatic lithotripsy, open techniques, etc. [5][6][7][8][9].

Presently, there are few publications devoted to the issue of urethral stones. In the majority of cases, they are based on the retrospective approach and include only isolated observations with the specified pathology. There are even fewer publications on the approaches to the management of patients with a combination of urethral stricture and urethral stones. Thus, the issue of the development of optimal tactics for the treatment of such patients remains acute. The present study aimed to analyze the authors’ experience of treatment for patients with a combination of short urethral stricture and urethral stone.

The retrospective study included 7 men with urethral stricture and urethral stone that underwent balloon dilatation with urethral stone extraction from January 2017 to September 2019. All patients had their diagnosis verified before the surgery using ultrasonic investigation (USI), non-enhanced computed tomography, and retrograde urethrography.

The patients’ age varied from 47 to 65 years old (median – 52 years old). The length of the urethral stricture ranged from 3 to 10 mm (median – 7 mm). In 2 cases (28.6%), the stricture was localized in the penile urethra, and 5 cases (71.4%), in the bulbose urethra. The authors established the following causes of the urethral stricture: traumatic – in 2 patients (28.6%) patients, inflammatory – 1 patient (14.3%), and idiopathic – in 4 patients (57.1%). Each patient had one urethral stone. The stone sizes ranged from 4 to 9 mm (median – 6 mm). The duration of symptoms varied from 2 months to 1 year (median – 8 months). None of the patients had pre-operative bladder drainage through cystostomy.

Uroflowmetry showed that all the observed patients had an obstructive type of urination. At the same time, the maximal urinary flow rate (Q max) ranged from 5.3 to 8.7 ml/s (median – 6.8 ml/s) and the residual urine volume was 50–150 ml (median – 106 ml).

The most common comorbid diseases included ischemic heart disease, hypertonic disease of II stage, femoral neck fracture, prostate adenoma, and diabetes mellitus type 2.

All patients underwent complex therapy that included anti-inflammatory (considering the results of bacterial urine tests and sensitivity to antibacterial drugs) and antisclerotic drugs to prevent infectious complications and urethral stricture recurrence.

The surgery was performed under local anesthesia (intraurethral introduction of an anesthetic agent) and the control of an electron-optical image converter in the conditions of an X-ray operating room by the following method. First, a hydrophilic guidewire was introduced into the urethra via a stricture segment up to the urinary bladder neck. Then, a 3.6 mm balloon catheter 6 Fr was introduced above the guidewire (Rapid Exchange; iVascular Xperience Inc., Spain) (Fig. 1). The distal end of the catheter is equipped with an inflatable balloon, which gets inflated through a contrasting agent infusion and expands the urethra. The balloon is set to achieve different diameters at different pressure. The distal part of the catheter is covered with a durable hydrophilic layer (HYDRAX), which minimizes friction and improves the catheter position control. When the balloon is placed in the area of the urethral stricture, a regular 10 ml syringe is used for inflating the balloon by injecting a radiological contrasting agent until the resolution of the stricture (Fig. 2). Dilatation of the area of the urethral stricture was provided by the pressure in this area to 10–15 atm (1 atm = 101,325 Pa). The average time to dilation was 5 minutes. The urethral lumen was dilated to 20 Fr.

The next step of the surgery included the grasping of the stone with a Dormia basket under the X-ray control (Fig. 3). This manipulation was made before the introduction of the endoscopic tool into the urethra so that the stone did not migrate to the proximal sections of the urethra or into the bladder under the pressure produced by the irrigation fluid. After an X-ray verification of the stone grasping with a Dormia basket, a ureteroscope Ch 9.5 was introduced in the urethra parallel to the basket tube to the level of the urethral stone fixation. After a visual verification of the fixation and mobility of the urethral stone, the stone was extracted using a Dormia basket with synchronous removal of the ureteroscope out of the urethral cavity (Fig. 4). The last step of the surgery included the installation of a 20 Fr urethral catheter for 21 days.

Postoperative follow-up of patients included uroflowmetry and USI evaluation of the residual urine volume 3, 6, 12, 18, and 24 months after the surgery. Urethrography was indicated to patients with suspected stricture recurrence based on subjective patients’ signs and uroflowmetry results. The criteria of the urethral stricture recurrence included patients’ complaints about the worsening of the urination quality in combination with a decrease in Qmax (less than 12 ml/s) and presence of a significant volume (more than 100 ml) of residual urine, as well as the necessity of any additional manipulations and surgical interventions for the restoration of the normal urine passage.

Statistical analysis. Statistical processing of the data was made using the software package StatSoft STATISTICA v. 17.0. The dynamics of the specified clinical parameters were evaluated using Wilcoxon’s test. The differences were significant at (p) < 0.05.

The time of surgery varied from 11 to 19 minutes (median – 13 minutes). None of the patients had any complications. In the early postoperative period, one patient had UTI. The time of postoperative hospitalization varied from 1 to 5 days (median – 3 days). The time of postoperative observation varied from 3 to 24 months (median – 14 months).

The results of a postoperative examination of patients are presented in Table 1. Statistical analysis showed that during the postoperative follow-up, in 6 out of 7 patients, Q max significantly increased in comparison with the baseline preoperative values (p < 0.05). Eighteen months after the surgery, only 1 patient (14.3%) had urethral stricture relapse verified by the results of uroflowmetry and retrograde urethrography, which was resolved by laser endoureterotomy. Thus, the rate of a successful outcome was 85.7% in the group of patients that were treated by the proposed method (6/7).

An example of successful treatment for a patient with ureteral stricture and urethral stone with the proposed method is the clinical case of Patient C. who was included in the study.

Clinical case. Patient C., 49 years old, male. The patient noticed a worsening of the process of urination. Half a year later, he applied to the hospital. The examination revealed a stricture in the bulbous part of the urethra approximately 0.6 cm and a 5 mm urethral stone. The patient underwent balloon dilatation of the urethra and extraction of the urethral stone. Within 24 months after the surgery, urethral recurrence was not observed. The examination 24 months after the surgery showed that Q max was 17.6 ml/s. There was no residual urine and no signs of narrowing of the urethral lumen by the results of retrograde urethrography (Fig. 5).

The obtained results of the application of the proposed treatment method for patients with urethral stricture and urethral stone using balloon dilatation in combination with stone extraction proved it to be promising. However, it is necessary to understand that this method of urethral dilatation is not a routine and frequently used technique in the treatment of urethral stricture, even though different international recommendations say that this technology is feasible for short strictures in some share of patients [10][11][12].

The mechanism of action of balloon dilatation on the urethral scar tissue has been described in several publications over the past years. A high-pressure balloon allows for adequate dilation of the urethral lumen. The dilation of the stricture is achieved via radial cracking and expansion of the surrounding fibrous tissue due to the applied high pressure. At the same time, radial expansion of the balloon dilator is provided via the distribution of radial impact along the balloon lumen and the radial impact is perpendicular to the mucous layer. This leads to a decrease in the shear load to the mucous layer and is associated with a reduction of tissue traumatization [13][14]. Thus, the vascularization in the spongy urethra can be preserved, which leads to less frequent postoperative hemorrhages and spongiofibrosis.

Several recent studies confirmed the high efficiency and safety of balloon dilatation. Yu et al. [15] compared the results of the application of balloon dilatation in 31 patients and direct vision internal urethrotomy (DVIU) in 25 patients with anterior urethral stricture. It was revealed that the time of surgery using balloon dilatation was significantly shorter than using DVIU (13.19 ± 2.68 min vs 18.44 ± 3.29 min). Besides, in the group of balloon dilatation, the main postoperative complications (urethral bleeding, UTI) were observed significantly rarer than in the group of DVIU (urethral bleeding: 2/31 vs 8/25; UTI: 1/31 vs 6/25). A 12-month follow-up showed that the rate of successful outcome was significantly higher in the group of balloon dilatation than in the group of DVIU (77.4% vs 44%, respectively). However, 36 months after the surgery, the difference between the groups was insignificant, and the rate of successful outcome was 35.5% after balloon dilatation vs 28.0% after DVIU. At the same time, the median time of recurrence was 17 months after balloon dilatation and 11 months after DVIU. These data indicate that urethral stricture recurrence can occur later after balloon dilatation. This hypothesis explains the only case of recurrence in the present study that was registered in a patient 18 months after the surgery.

Veeratterapillay and Pickard [16] in their review article also admit that the issue of the advantage of balloon dilatation over DVIU in the long-term perspective is understudied. These authors reported that the rate of successful treatment in patients with balloon dilatation and DVIU varied from 10 to 90% within a 12-month follow-up, although additional intermittent sessions of balloon dilatation can prolong the recurrence-free period of the disease.

Presently, there are no published references to the management of patients with urethral stricture and urethral stones that underwent balloon dilatation with further urethral stone extraction. The most frequent options of treatment for such patients are contact methods of lithotripsy in combination with DVIU [3][17][18]. Thus, the proposed approach is innovative in terms of a combination of two techniques for the treatment of short urethral stricture and urethral stone extraction (Patent RU 2745238 C1). Still, there are some limitations to the study. First, a small sampling of patients (7 people). Second, a short follow-up period (4 patients had an 18-month follow-up and 1 patient had a 24-month follow-up). Third, a decrease in the efficiency of the approach in a long-term perspective (among 4 patients with an 18-month follow-up, a favorable outcome was observed in 75%, while the evaluation of all follow-up results showed 85.7%). Thus, despite the promising results of the proposed approach, it is still early to make conclusions on the feasibility of the clinical application of this innovation. The authors believe that the approach requires further research via randomized studies with larger samplings and long-term postoperative follow-up. At this stage, the approach can be recommended only for specialists and clinics with major experience in this area.

The proposed endoscopic approach to the treatment of men with a combination of two nosology forms (urethral stricture and urethral stone) showed significant results. Still, it must be mentioned that such results can be obtained only in men with a short anterior urethral stricture, primarily, in the bulbous part of the urethra. Thus, it is important to follow a procedure of adequate choice of patients for this treatment option. Besides, this tactic of treatment can be considered as an alternative to DVIU and reconstructive surgeries on the urethra in patients with severe associated pathology who have contraindications to general anesthesia or refuse surgical manipulations for their reasons. Although this study is a pioneer in the management of patients with a combination of urethral stricture and urethral stone, its significant limitations include a small sampling, a short follow-up, and a retrospective design. The conclusion on the efficiency of this approach can be made based on further prospective evaluation of this approach application results in studies with larger samplings.