Definition Abnormal communications between urinary & genital organs. Remember 2 golden rules 1st rule: urine may escape from ureter tube, uterus, cervix, vagina bladder tube, uterus, cervix, vagina urethra always vaginal. 2nd rule in naming a fistula, Part of the urinary tract is 1st to be described
Necrotic Obstetric Fistula Prolonged compression of soft tissues between head & brim of a narrow pelvis. → ischaemia, pressure necrosis & sloughing of base of the bladder. Urethra is also often involved. Slough takes some days to separate → Incontinence develops 5-7 days after labour Such fistulae are often surrounded by dense fibrosis
Traumatic Obstetric Fistula Direct injury to bladder wall by sharp instrument (perforator or decapitation hook) during a difficult labour Forceps rarely cause it Incontinence Appears immediately After Labour
Traumatic Fistula Surgical trauma: Bladder may be injured during vaginal operation as anterior colporrhaphy during abdominal operations as hysterectomy. Direct trauma: is a rare cause, but cases have occurred as a result of impalement.
Other Causes Inflammatory disease: result from Bilharziasis of bladder Tuberculosis of bladder. A pelvic abscess may open into bladder & vagina Malignant neoplasms: As advanced carcinoma of cervix or of bladder, or vagina By direct invasion of the wall and ulceration. Radium necrosis: Sloughing of the bladder As a complication of radium treatment used for cure of malignant disease in pelvis
Symptoms Incontinence of urine Complete (large fistula) OR Partial (small or high fistula) DD: uretero-vaginal fistula. Symptoms of vulvitis: Pruritus, burning pain due to continuous discharge of urine. Cystitis Due to ascending infection from vulva
Diagnosis History of incontinence following labour or operation. Several days after labour necrotic obstetric fistula Immediately after difficult labour traumatic fistula. Palpation of anterior vaginal wall: Large fistula Can be felt Small fistulas cannot be felt, but surrounding fibrosis is usually palpable
Diagnosis Inspection of the anterior vaginal wall In Sims’ position or left lateral (semi-prone) position With the use of Sims’ speculum.
Diagnosis For small and high fistula Dye test: Injection of methylene blue into bladder by a catheter to outline the fistula while anterior vaginal wall is inspected by use of Sim’s speculum. DD: uretrovaginal fistula Sometimes a metal catheter or sound is passed through the urethra to appear at the fistulous opening.
ManagementProphylaxis: Antenatal: Diagnosis of abnormalities that possibly result in fistula formation contracted pelvis malpresentations During labour Diagnose and deal with: prolonged labour contracted pelvis Malpresentations Risky operations should all be avoided high forceps forceps with incompletely dilated cervix risky destructive operations.
Management If injury to the bladder is discovered during a difficult labour, Don’t suture the tear due to tissue oedema and friability. fix rubber catheter for 10 days The tear may heal completely or be much smaller If the injury is detected some time after labour, as in cases of necrotic fistulas, operations done except at least 3 months after delivery to allow for maximum involution of the tissues.
Preoperative Preparation Treat vulvitis: Cover skin of the vulva, and inner thighs by a thick layer of Vaseline, zinc oxide ointment or any bland ointment, to prevent maceration of the skin by the continuous discharge of urine. Renal function tests: Culture of urine, if pathogenic organisms are found, patient is given urinary antiseptics until urine is sterile.
Methylene blue test to differentiate a small vesico-vaginal fistula from a uretero-vaginal fistula. 3 pieces of gauze are placed in the vagina 200 cc of sterile fluid coloured with methylene blue is Injected into the bladder The lowest piece of gauze is discarded as it is usually stained during filling the bladder. If the middle or upper pieces stain → fistula is vesical If none of the pieces stain and the upper one is wet with uncoloured urine → fistula is ureteric. If all are dry and unstained → excludes vesical or ureteric fistula.
Cystoscopy Determine relation of the fistula to ureteric openings in bladder Exclude multiple fistulas Reveal associated bladder pathology. Chromocystoscopy IV Injection of 4 c.c. of 0.4% indigocarmine solution If kidney function is good → Blue efflux from the ureter in 4 minutes.
Operationflap-splitting operation, or dedoublement Circular incision around the fistula. The 2 short longitudinal cuts upwards and downwards Long. incision Through the thickness or the vagina but not the bladder. → 2 flaps of vaginal wall. Circular incision Free mobilization of the vaginal Fistula flaps from the bladder over a wide area, at least 1.5 cms around the fistula.
Operation The hole in bladder is then closed by 2 layers of interrupted sutures going through muscle wall only & not piercing the mucous membrane. The vagina is then closed by interrupted sutures going through its whole thickness. A rubber catheter is fixed in the urethra Tight vaginal pack to prevent reactionary haemorrhage.
The saucerisation operation(Sim’s operation) Indicated If tissues are too adherent and fibrosed to do flap splitting After failure of the flap splitting. Technique: Edge of the fistula is excised removing a wider part of the vagina than of the muscle wall of the bladder Edges of both organs are simultaneously coapted together by the use of nonabsorbable sutures Certain high fistulae are better treated by abdominal (transperitoneal or transvesical) repair.
Postoperative Care Recumbent position The bladder should be constantly empty. Fluids (3 litres/day). Urinary antiseptics & antibiotics. Vaginal pack is removed 24 hours after operation. Catheter is removed after 10 days. After its removal the patient is instructed to void urine every two hours by day & every four hours by night, to avoid over-distension of bladder & disruption of suture line.
Subsequent Management Patient is instructed to avoid sexual intercourse for 3 months avoid pregnancy for 1 year Caesarean section is almost absolutely indicated.
URETERO-VAGINAL FISTULA Cause: Injury to ureter during a gynaecological operation as hysterectomy may develop following a difficult labour. It leads to incomplete incontinence Urine from affected ureter escapes from vagina while bladder fills up & empties normally from other ureter It is always small & high up in vagina lateral to cervix. Differentiated from a vesico-vaginal fistula by: by methylene blue test. Cystoscopy shows ureteric efflux on one side only.
Prophylaxis Ureteric injury can be avoided by pre-operative intravenous pyelography ureteric catheterization proper surgical technique.
Treatment Abdominal re-implantation of ureter into bladder. If not possible, ureter is transplanted into sigmoid colon. If kidney function is very poor on the affected side → kidney can be sacrificed.
Kidney Function Tests Blood urea: Normally 20-40 mg%. Specific gravity of urine before and after water administration (water concentration test): Normally high before, low after In chronic nephritis → low fixed S.G. of about 1010. Urea concentration test: Normally urea in urine should be 2% or over after administration of 15 grams of urea by mouth. Urea clearance test: It is a delicate test. It indicates the no. of cm3 of blood cleared of urea per minute Average = 70-120% < 50% → renal impairment. Intravenous pyelography.
Types Of Incontinence Of Urine1. True incontinence genito-urinary fistula.2. Stress (Sphincter) incontinence weakness of Internal urethral sphincter.3. Urgency incontinence severe inflammation leading to marked irritation of bladder & so urge to pass urine cannot be inhibited & some urine will pass involuntary while patient is in her way to W.C.4. False incontinence retention with overflow5. Nocturnal enuresis.
Causes Of Retention Of Urine Cause of urinary retention is an impacted pelvic mass. Diagnosis is made clear by attention to associated symptoms
Associated Conditions Condition DiagnosisPrimary amenorrhea → HaematocolposSecondary amenorrhea → Retroverted gravid uterusMenorrhagia → Uterine fibroidNo menstrual upset → Ovarian or broad ligament tumourIrregular bleeding → (1) threatened abortion from a retroverted gravid uterus, → (2) pelvic haematocele → (3) pelvic abscessLabour → Descent of the foetus to from a pelvic tumour