Urinary incontinence after prolonged labour and caesarean section

A 30 year old woman, who had had five children and two abortions, presented to the outpatients’ department with a one year history of constant dribbling of urine after her last delivery. This was a caesarean section after a prolonged obstructed labour. The baby had a transverse lie and a two day history of an impacted shoulder and hand prolapse. He had a subsequent intrauterine death.

Questions

(1) What are the possible causes for her problem?

(2) What investigations would you carry out to confirm your diagnosis?

(3) What does the unlabelled arrow in fig 1 show?

Fig 1 Gynaecological examination of the patient under anaesthesia

(4) How would you interpret the investigation in fig 2?

Fig 2 Intravenous urogram in the premicturition phase

Answers

(1) Stress incontinence after prolonged labour; overflow incontinence after prolonged labour; urinary fistula after prolonged obstructed labour; or urinary fistula after caesarean section.

(2) Vaginal examination under anaesthesia; intravenous urogram; cystoscopy; or urodynamic studies.

(3) The two clips are drawing the vaginal wall laterally to expose the midline hole (unlabelled arrow) in the anterior vaginal wall more clearly. This is a fistula, which communicates with the bladder—the pink mucosa of bladder can be seen. A fistula is an abnormal communication between two epithelial surfaces, either between two internal organs or between an organ and the exterior. Therefore, this patient had a vesicovaginal fistula.

(4) The intravenous urogram shows incomplete filling of the bladder and a constant stream of dye emerging from the vagina. Because it is in the premicturition phase there should be no escape of dye from the bladder unless there is abnormal communication.

Discussion

Obstetric fistula is still a noteworthy complication of prolonged labour in the developing world. The exact number of cases worldwide remains unknown but is estimated to be close to two million.¹

In prolonged labour the bladder is trapped between the presenting part and the pubic symphysis. This leads to pressure necrosis of the bladder wall and the vagina, leading to sloughing and fistula formation. Fistulas can be classified according to site, which is useful for further management:

• Vesicovaginal (bladder and vagina)
• Vesicouterine (bladder and uterus)
• Ureterovaginal (ureter and vagina)
• Ureterouterine (ureter and uterus)
• Urethrovaginal (urethra and vagina)

Management of obstetric fistulas involves identifying the site of the fistula followed by corrective surgery, on the basis of the history, examination, and further investigations.

History

Constant dribbling of urine implies an abnormal communication between the bladder and the vagina or a ureter and the vagina. If the patient can still pass urine voluntarily in addition to this involuntary dribbling this could be a ureterovaginal or a ureterouterine fistula in which one ureter is still functioning. Ureterouterine fistulas are rare but associated with iatrogenic injury during caesarean section, when one ureter is inadvertently stitched to the uterus.

The timing of the onset of the urine leak after operation can help in diagnosis after a caesarean section: a leak immediately after operation indicates iatrogenic injury, and a late onset leak indicates fistula formation secondary to pressure necrosis in the preceding prolonged labour. The latter can occur up to 14 days after delivery. It is important to ask about cyclical blood in the urine (menuria) because this would imply a connection between the uterus and the bladder.

Examination

In this centre patients are always examined under anaesthesia. Patients are often hesitant to be examined awake because of discomfort and embarrassment associated with the condition. With the patient relaxed it is much easier to carry out a thorough examination to identify the site and size of the fistula. An examination under anaesthesia can identify only a vesicovaginal fistula.

In this patient the fistula was easily visualised and hence the dye test was not needed. The dye test is indicated for small fistula that cannot be visualised on examination. A swab is inserted into the lateral fornices of the vagina, and methylene blue is injected into the bladder through a Foley’s catheter. A swab stained with dye implies a vesicovaginal fistula. If it is not blue but is still wet with urine there is an abnormal communication between the ureter and the vagina.

A double dye test can be used in which phenazopyridine (an orange dye) is given orally and methylene blue is given through the urethra. Orange staining of the renal urine will occur in a ureteric fistula.²

The three swab test is traditionally performed by placing three swabs vertically in the vagina to try to identify the level of the fistula. This has been replaced by the dye tests and is particularly difficult to interpret in the case of multiple fistulas.³

Cystoscopy is a useful preoperative assessment that identifies the size and site of the fistula and its precise relation to the ureters. Large fistulas may need to be blocked with a swab during cystoscopy to optimise image quality by preventing water from flowing out from the fistula.

Surgical treatment

Obstetric fistulas are usually repaired three months after obstructed labour, so that inflammation and infection are resolved. The patient is placed in the reverse Trendelenburg or lithotomy position, and the surgical approach is abdominal, vaginal, or both.

The surgical technique involves dissection along a plane between the vagina and the bladder. The vaginal wall is freed from the adherent bladder wall, resulting in mobilisation of the bladder, which is a prerequisite to closing the defect. In this woman, after tidying up the fistula margins, the bladder was stitched with polyglactin 910 (Vicryl) 2-0 in two layers, and the vagina was stitched separately.

After operation the patient is nursed in a lateral position, and the bladder is drained continuously to prevent any pressure at the site of fistula repair. At this institution this is done using a suprapubic and a urethral catheter, which are left in for two and three weeks.

Obstetric fistulas, although rare in the developed world, are a cause of morbidity in women in the developing world. The social implications are catastrophic and hence prompt recognition and treatment of these patients, including social rehabilitation, are essential parts of management.

Competing interests: None declared.

Patient consent: Obtained.

Provenance and peer review: Not commissioned, externally peer reviewed.

1. Donnay F, Weil L. Obstetric fistula: the international response. Lancet 2004;363:71-2.
2. Raghavaiah N. Double-dye test to diagnose various types of vaginal fistulas. J Urol 1974;113:811-2.
3. Clement K, Hilton PL. Diagnosis and management of vesicovaginal fistula. J Obstet Gynecol 2001;3:173-6.

      

 Printable version    Download PDF   E-mail this to a friend   Respond to this article