1 INTRODUCTION

Urethral prolapse (UP) is a very rare benign condition which occurs in up to 80% of cases in prepubertal girls, the rest occurs in postmenopausal women.1, 2 UP was first described by Solingen in 1732.3 The etiology is still unknown, but lack of estrogen and hypermobility in the perineum have previously been described as possible underlying factors.4 Another theory was put forward by Lowe et al, claiming that UP occurs because of a cleavage plane between the outer circular and the inner longitudinal smooth muscle layers in the urethra together with increasing intra-abdominal pressure.5 UP occurs when the distal urethral mucosa emerges through the external meatus and creates a circular protrusion.6 This causes urogynecological symptoms such as vaginal bleeding, hematuria, dysuria, frequency, and urinary retention.7

It can be difficult to differentiate UP from other conditions in this area including urethral caruncle, prolapsing ureterocele, and even urethral cancer. The optimal management remains controversial between conservative approaches and through surgical repair. The nonoperative treatments include local estrogen, topical antibiotics, or sitz baths.8 Surgical management through a circumferential excision of prolapsed urethral mucosa has previously been described.4 Herein, we present a case of UP in a postmenopausal woman who presented with acute urinary retention (AUR).

2 CASE REPORT

An 86-year-old woman with a normal body mass index (BMI) of 24 presented to the emergency room with AUR for the past 6 hours and perineal pain that she had experienced for approximately 1 month. A residual urine volume of 950 mL was measured. Under a local anesthetic gel, an indwelling 14F catheter was placed with 10 mL in the catheter balloon. Urinalysis revealed leukocytosis and a positive nitrite test. A urine culture of midstream urine, undertaken with the necessary hygiene steps in order to minimize contamination, revealed two different bacterial colonizations: Klebsiella pneumonia and Escherichia coli. A treatment with 200 mg pivmecillinam three times a day according to national guidelines was commenced. Her medical history included atrial fibrillation, chronic obstructive pulmonary disease (COPD, grade IV), and hiatus hernia. She had undergone unilateral oophorectomy for ovarian cancer 13 years ago. She had no previous history of pelvic radiation, pelvic inflammatory disease, or other traumatic injuries to the pelvic region. Her obstetric history included four normal vaginal deliveries and menopause at the age of 49 years. She had a cystocele for which she had a topical estrogen and a prolapse ring.

The patient was admitted to the Department of Urology where physical examination revealed an atrophic vulva and vagina. Around the urethral meatus, a 2 × 3-cm severely sore, blue/purple polyp was identified. The polyp looked incarcerated with signs of necrosis (Figures 1 and 2). A preliminary diagnosis of UP was made based on the abovementioned macroscopic findings. One day after admission, she underwent an excision of the UP. She underwent cystourethroscopy preoperatively which showed a 3-cm normal urethral mucosa with a slight edema. The surgery was performed using the four-quadrant excisional technique,8 whereby the base of the prolapsed mucosa was defined and excised circumferentially around a Foley catheter in quadrants. The healthy urethral mucosal margin was sutured to the vestibule using absorbable sutures (size 4-0) at positions 12, 2, 4, 6, 8, and 10 o'clock to effectively achieve a mucocutaneous anastomosis (Figure 3).

Urethral prolapse in a premenopausal woman, preoperative

Urethral prolapse in a premenopausal woman, preoperative

Urethral prolapse in a premenopausal woman, postoperative

She was discharged after 1 day with a local estrogen ointment. The histopathological examination of the excised specimen revealed a non-keratinized squamous epithelium with abundant inflammatory cells, and no atypia was found. On her first-month follow-up visit to the operating surgeon, the patient remained asymptomatic, continent, and with no further episodes of perineal pain. The physical examination revealed a complete anatomical resolution with no prolapse.

3 DISCUSSION

As previously mentioned, UP is an infrequent diagnosis and easily confused with a urethral caruncle. In our case, a urethral caruncle was the initial suspected diagnosis in the emergency room. Pelvic examination is sufficient for a diagnosis9 because UP has a typical appearance on physical examination as a hemorrhagic and pink mass surrounding the external urethral meatus. A caruncle is usually described as a solitary nodule arising from the posterior lip of the external urethral meatus; UP, however, is circumferential around the external urethral meatus.10 The main complaint is usually discomfort in the external genitalia or bleeding and sometimes AUR, as in our case. The mechanism behind UP is still unclear, but a multifactorial etiology including weakness in the perineal musculature coupled with chronic increasing intra-abdominal pressure might be assumed. A relative weakness in perineal muscles and advanced COPD are assumed to have played a role in the occurrence of UP in our patient, a finding consistent with Lowe's theory.5

It has previously been speculated on possible predisposing factors for UP, including COPD, recurrent urinary tract infections, constipation, estrogen deficits, cystocele, and post incontinence procedures with bulking agents.11 Furthermore, overweight children might be more susceptible to UP secondary to an elevated resting abdominal pressure3 in contrast to our patient who had a normal BMI. In some cases, it is easy to perform a manual reduction of the UP provided the patient presents in an early phase. However, in the case of late arrival to the emergency room and/or an increase of the protruding mass, the mucosal vascularity could worsen. As a result of this, it may be strangulated and necrotized making a manual reduction painful or even impossible.4

The conservative management was presented by Ko et al, who described an intralesional injection of hyaluronidase and 2% lignocaine followed by manual reduction of the prolapse. However, the patient still had to undergo an excision 3 weeks later because of recurrence.12 As such, in patients with severe symptoms and a prolonged history with accompanying pelvic weakness, surgery excision remains a reasonable choice. Therefore, due to the symptoms that had persisted for weeks and the presence of suspected strangulating, the only treatment option for our patient was a surgical excision, and no attempt to manually reduce the mass was undertaken. Yi Wei et al. found that 84% of UP cases (75/89 girls <16 years) were successfully treated by surgery.13 In another study reported by Ballouhey et al, all patients who underwent surgery had no recurrence after a mean follow-up time of 28 months.14 Similarly, Herzberg et al reported on 24 girls (mean age of 4.9 years) presenting with urogenital bleeding, where 88% underwent surgical repair with good results.15

The total removal of the prolapsed urethral mucosa and anastomosis of the remaining urethral wall to the vestibule margin were considered as a standard treatment in previous studies.4 Some urologists remove the catheter immediately postoperatively and others after 3 to 5 days. In our case, the patient needed continued care in another surgical unit because of cholestasis, and therefore she had the catheter for 11 days. There is usually no need for antibiotics in ordinary cases, but since our patient had a positive urine culture, she received antibiotics. To the best of our knowledge, there are not many cases in the English literature describing UP in postmenopausal women presenting with AUR which disappears after surgical excision.

In conclusion, UP is an uncommon, sometimes misdiagnosed condition, and a necrotized UP is an even rarer urological emergency. The increase of abdominal pressure, the lack of estrogen, and the perineal muscle weakness have been suggested as possible risk factors. The management is controversial, and to date no consensus exists. This review has confirmed that the clinical picture is sufficient for a diagnosis, and surgical excision of the prolapsed urethral mucosa is appropriate if there are signs of strangulation.

DISCLOSURE STATEMENT

The authors report no conflicts of interest.

PATIENT CONSENT

Written informed consent was obtained from the patient for both the publication of this case report and the accompanying images.