Post-Operative Voiding Dysfunction Challenges in Obstetrics & Gynecology Kuwait Feb 8, 2017 Dante Pascali MD, FRCS(C) Urogynecology Division Head Assistant professor, University of Ottawa Canada

Disclosures Consultant for Pfizer, Astellas and Duchesnay.

Outline Introduction Incidence Risk Factors Etiology Diagnosis Management

Definition Post-operative urinary retention (POUR) is impaired voiding after a procedure despite a full bladder that results in an elevated post-void residual1. Baldini et al, Anesthesiology 2009

Introduction POUR is common after gynecologic surgery, especially pelvic reconstructive surgery. Retention rate after pelvic surgery is 2-43%1 Bladder volume >400 ml (when no catheter in situ) Post-surgical impaired voiding Elevated post-void residual Usually resolves spontaneously by 6 weeks post-op. 1. Geller et al., Int J of Women’s health,

Perioperative Risk Factors Age greater than 50 (2x) History of pre-existing urinary retention Neurological conditions >750 ml IV fluid intraoperatively Surgery > 2 hours Intraoperative anticholinergic use (atropine, glycopyrrolate) Regional anesthesia Opioid analgesia Incontinence surgery (varies with type of procedure) Radical pelvic surgery Constipation Pain Blood loss

Predicting Post-op Voiding Dysfunction ?Association between peak flow rate, detrusor pressure during voiding and presence of straining with voiding 12 fold risk of retention in patients who are valsalva voiders. Other study (Lemack ‘08) showed no association between preoperative urodynamic studies and post-op voiding dysfunction or the risk of surgical revision in pubovaginal sling group. Mostafa ‘11 – Pre-op UDS not predictive of post TVT-O VD Kirby ‘11 – Pre-op EMG not predictive of post-op VD Wheeler ‘08 - Max flow rate on pre-op uroflow best predictor of passing initial trial of voiding after MUS. Not correlated with passing second voiding trial. ‘Sanses ‘11 hesitating urinary stream associated with voiding dysfunction Chung ‘10 – concomitant anterior repair was associated with voiding dysfunction

Etiology of postoperative voiding dysfunction in women Failure to sense bladder filling Anesthesia/narcotics Nerve injury Surgical Acute overdistention injury Failure to contract the bladder Pre-existing voiding dysfunction Mechanical obstruction of the urethra Incontinence procedures POP Urethral perforation/foreign body Constipation / pelvic mass Functional obstruction of the urethra Failure to relax the pelvic floor

Types of pelvic surgical procedures and risk of POUR Cystocele repair (OR 2.5) Levator plication (OR 4.3) Kelly plication (OR 5.1) Anorectal surgery (16.7%) TVT (2-4%) Burch (4-22%) Pubovaginal sling (4-10%) Radical hysterectomy (20%) Low anterior resection (68%)

Causes of Post-op Voiding Dysfunction Pre-op voiding dysfunction (except where prolapse as the causative agent is corrected) Regional anesthesia (spinal, epidural) Ambulation returns before bladder function. Denervation at time of surgery (radical hyst. – 20%) Cystotomy (2-5 % with retrobubic MUS) Bladder overdistention injury Post-op analgesics Urethral obstruction Vaginal pack Hematoma Incontinence procedure Prolapse Urethral injury Pelvic floor hypercontraction

Anesthetic Agents Conduction anesthesia (epidural or spinal) Blocks the sensory and motor nerve impulses of the sacral spinal cord. Suppresses the micturition reflex. Decreases detrusor contractions. Increases bladder capacity. Bladder function returns once regresses to S2 or S3. Normal bladder function returns 1-3.5 hours after ambulation returns.

Bladder Overdistention Injury >120 % of a normal bladder capacity for >24 hours Chronic bladder distention evolves slowly. Acute overdistention can result in bladder wall ischemia in 30 minutes. Ischemia can be followed by reperfusion injury which results in prolonged bladder dysfunction. Can occur during labour and delivery, yet only diagnosed post-partum.

Diagnosis Clinical Bladder Catheterization Bladder Ultrasound Lower abdominal pain Palpable bladder Straining to void Slow urine stream has has the highest sensitivity and specificity for predicting an elevated PVR (Lukacz et al 2007) Bladder Catheterization Volume > 400 ml Elevated PVR > 150ml or > 1/3 voided volume Bladder Ultrasound

Trial of Voiding Retrograde (more accurate and preferred by patients) Fill to 300ml and void >200ml Spontaneous Await strong urge to void and check PVR Patients who report a stream of 50% or greater can safely be discharged home regardless of PVR (Ingber 2011)

Management Early identification prior to discharge Initial continuous bladder drainage with indwelling foley catheter. Teach intermittent self-catherization Record of voided volumes and PVRs Continue until PVRs consistently less than 1/3 of voided volume and total bladder volumes are not causing overdistention. Trial of voiding in outpatient setting Assessment of pelvic floor tone and consider pelvic PT Assessment of prolapse and excessive suburethral support. Avoid overdistension injury to bladder

Treatment of sling obstruction Most cases of POUR will resolve spontaneously. Surgical options: sling stretching, sling release, sling resection or urethrolysis. Early vs Late release of sling. Usual release by 6 weeks post-op. Early release may have higher success rate in improving voiding function. (South ‘09) 70-90% resolution of voiding dysfunction. 10-20% risk of de novo SUI.

Sling Release “J” cut of sling – Kasturi ‘11 Cut at 9 or 3 o’clock 100% resolution of VD May help in avoiding de novo SUI

Urodynamic Studies Indicated where there is no obvious obstruction on clinical exam or where patient’s symptoms are inconsistent with the medical and surgical history. Can help to explain issues with bladder contractility, urethral tone and urethral obstruction. A pressure-flow study can be helpful when the patient is unable to void. Obstruction is defined as a maximum flow rate < 15 ml/sec with a simultaneous detrusor pressure >20 cm H20 (Chassagne et al, 1998)

Voiding dysfunction remote from surgery May occur months to years after surgery. May be due to pelvic organ prolapse or urethral erosion of mesh.

OAB and urethral obstruction Beware of patients that have incontinence surgery for mixed incontinence. PVR’s may be normal as the overactive detrusor contraction overcomes the urethral resistance. If this is unrecognized this can result in irreversible bladder dysfunction Can be diagnosed with an elevated urethral pressure profile or by measuring peak detrusor pressure associated with maximal urinary flow.

Conclusion Pre-op counseling of patients of possible post-op voiding dysfunction is important. Identify risk factors that may predispose patient to urinary retention. Early identification. Trial of voiding Sling release as necessary