A 49-year-old woman, gravida 5 para 5, comes to the office due to urine leakage. Over the last 2 months, the patient has had constant urinary leaking, requiring her to wear a pad day and night. She has no dysuria, urgency, or vulvar pruritis. The patient has type 2 diabetes mellitus that is well controlled with oral medication. Two years ago, she received brachytherapy and external-beam pelvic radiation for cervical cancer. She had smoked a pack of cigarettes daily for 25 years but quit 6 years ago. BMI is 43 kg/m². Pelvic examination shows no urethral leakage with Valsalva. There are postradiation changes and a pool of clear fluid in the vagina. Postvoid residual volume is 20 mL. Urinalysis results from catheterization are as follows: Which of the following is the most likely cause of this patient's symptoms?

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Explanation: 11ec25c8_d9e7_d9dc_bc81_815d0a22635c_MD0003_00 This patient's constant urinary leaking is due to a vesicovaginal fistula, an abnormal communication between the bladder and vagina. The proximity of the bladder and vagina make them vulnerable to fistulization, and patients develop symptoms with variable time frames: immediately following intraoperative bladder injury (eg, cesarean delivery, hysterectomy) weeks or months following surgery or childbirth (eg, obstructed labor) due to tissue necrosis and sloughing years after pelvic radiotherapy as a delayed presentation of radiation-induced microvascular injury (ie, endarteritis) and progressive tissue ischemia and breakdown (as seen in this patient) The aberrant connection between the bladder and vagina allows urine to constantly drain into the vagina, creating continuous, painless urinary leaking. Diagnosis is typically clinical, with evidence of pooling of clear fluid (ie, urine) in the vagina on pelvic examination; an area of raised, red granulation tissue or a vaginal defect may also be seen. Bladder dye testing may identify small fistulas that are difficult to visualize. Treatment is with surgical repair and bladder decompression (ie, catheterization). Bladder dye testing (Choices B and F) Stress urinary incontinence (SUI) is the intermittent, involuntary loss of urine with increased intraabdominal pressure (eg, coughing, laughing). SUI is due to either decreased urethral sphincter muscle tone or urethral hypermobility from weakened pelvic floor muscles. Although this patient's multiparity puts her at risk for SUI, there is no urethral leakage with Valsalva on pelvic examination, making this diagnosis unlikely. (Choices C and E) Overflow incontinence causes continuous, painless loss of urine due to chronic urinary retention. Underlying causes include diminished contractility of the bladder detrusor (ie, neurogenic bladder from diabetes mellitus) and external compression of the urethral outlet (eg, fibroids, prolapse), impeding bladder emptying. Urinary retention causes an elevated postvoid residual (≥150 mL), not seen in this patient. (Choice D) Excessive involuntary detrusor muscle spasms (overactive bladder) create a sudden urge to urinate, typically followed by an immediate loss of urine. This patient has no urinary urgency. Educational objective: A vesicovaginal fistula, an aberrant connection between the bladder and the vagina, can have a delayed presentation years after pelvic radiotherapy. There is typically continuous, painless leakage of urine as the bladder constantly drains into the vagina. References: Urological complications after radical hysterectomy with postoperative radiotherapy and radiotherapy alone for cervical cancer. (http://www.ncbi.nlm.nih.gov/pubmed/29595646) Female voiding dysfunction and urinary incontinence. (http://www.ncbi.nlm.nih.gov/pubmed/29406060)

A 49-Year-Old Woman, Gravida 5 Para 5, Comes to the Office