Urinary retention: includes male LUTS lecture

Question 1

LO: Explain the mechanisms by which urinary retention occurs:

obstruction of the urethra, weakened bladder muscle, and innervation problem

Define urinary retention

What are the two types of urinary retention?

Answer 1

• Define urinary retention: bladder that does not empty completely, or at all
• Acute urinary retention:
  
  • sudden inability to pass urine
  • usually painful/ uncomfortable, tender distended bladder
  • residual urine ~600 ml
  • requires emergency catheterisation
  • It can cause: UTI, AKI, post obstructive diuresis, hydronephrosis
• Chronic urinary retention:
  
  • Gradual (months- years) development of urinary retention
  • often asymptomatic and painless with postvoidal residual urine
  • High pressure- affects renal function
  • BPH is the most common cause
  • Can cause: UTI, AKI, post obstructive diuresis, hydronephrosis
• Can get acute on chronic –> painful with large residual urine

Question 2

What are the causes of acute urinary retention?

Answer 2

• Obstruction of the urethra:
  
  • BPH
  • urethral stricture - narrowing or closure of urethra, post UTI, surgery/ injury, prostatitis, meatal stricture (opening at end of urethra becomes constricted)
  • urinary tract stones or clot retention following haematuria
  • cystocele - bulging of bladder into the vagina, abnormal position causes compression of urethra
  • rectocele - bulging of rectum into vagina, may compress urethra
  • constipation - hard stools in rectum compress urethra
  • tumour - renal cancer, ureter, bladder, prostate, urethral, retroperitoneal masses
  • gravid uterus
  • fibroid or ovarian cyst - obstruct urethra
• Nerve problem -
  
  • cauda equina
  • cord compression
  • trauma
  • parkinson’s
  • MS
  • diabetes
• Medication
  
  • anticholinergics
  • opiods
  • BZDs
  • NSAIDs
  • alcohol
  • CCB’s
  • antihistamines
  • TCA’s
• Weakened bladder muscle

Question 3

Explain the physiology underlying the micturition process:

Explain underlying neurology of storage phase

Answer 3

• micturition has two discrete phases: storage/continence phase and voiding phase
• Continence phase:
  
  • controlled by continence centres in the brain –> control continence centres of spinal cord
  • storage requires detrusor relaxation and simultaneous contraction of both internal and external urethral sphincters
  • bladder and IUS under control of SNS
  • EUS under control of somatic NS
  • SNS –> From cerebral cortex to pons (pontine continence centre) –> sympathetic nuclei spinal cord –> Sympathetic hypogastric nerve (T10-L2) –> detrusor muscle relaxation (B3 adrenoreceptors) and contraction IUS (stimulates alpha 1 adrenoreceptors) at bladder neck.
  • EUS under voluntary somatic control –> impulses to EUS travel via Pudendal nerve (S2-S4) to nAchR on muscle of EUS.

Question 4

Explain underlying physiology of voiding process:

Answer 4

• Destrusor muscle relaxes as the bladder fills, rugae distend and constant pressure in bladder is maintained = stress- relaxation phenomenon
• capacity of bladder 300-550 ml, afferent nerves in bladder wall signal need to void at ~400ml
• passing of urine under parasympathetic control - bladder afferents signal ascend through spinal cord and project to pontine micturition centre and cerebrum
• upon voluntary decision to urinate neurones from pontine micturition centre fire to excite sacral preganglionic neurones
• subsequent parasympathetic stimulation of pelvic nerve (S2-S4) causes release of Ach –> M3 muscarinic Ach receptors on destrusor muscle –> contraction
• Pontine micturtion centre inhibits SNS stimulation of internal urethral sphincter –> relaxation
• conscious reduction in voluntary contraction of external urethral sphincter from cerebral cortex allows distention of urethra and urine passing.

Question 5

LO: Understand common and important causes of urinary retention including:

BPH pathophysiology

Answer 5

• BPH pathophysiology: increased proliferation of stromal and epithelial cells of prostate gland with decreased apoptosis, arises in periurethral and transition zones of the prostate. Results in bladder outlet obstruction - both due to increased epithelial tissue and increases in stromal smooth muscle tone. Large number of alpha adrenergic receptors in prostate caspule/stroma/bladder neck.

Question 6

LO: understand the common and important causes of urinary retention including:

BPH History/ Key Features

Answer 6

Presentation: Storage symptoms and Voiding symptoms

• Frequency
• urgency
• nocturia
• incontinence
• weak stream
• dribbling
• dysuria
• straining
• incomplete emptying

Question 7

LO: understand the common and important causes of urinary retention including:

BPH Key examination features

Answer 7

• DRE:
  
  • prostate volume > 30 g
  • nodules or tenderness–> suspicious of prostate cancer or prostatitis.
  • Assess anal sphincter tone
  • assess prostate for nodule or rectal masses
  • Smooth, soft prostate with pain = prostatitis
  • Smooth rubbery = BPH
  • Lumps/ hard/ irregular areas = prostate cancer.
• Abdo exam for palpable bladder –> inspection of external meatus
• neurological assessment

Question 8

LO: describe what bedside/clinical/lab/radiological investigations appropraite to investigate urinary retention

BPH: investigations

Answer 8

• Urinary frequency/ volume chart for a few days
  
  • polyuria > 3 L urine in 24 hours
• Bedside urinalysis to rule out UTI
• Lab: Serum PSA - dependent on findings of DRE
  
  • Offer PSA testing in men > 50 yrs who request/ symptomatic men
  • consider if LUTS present, ED, visible haematuria, unexplained symptoms that could be due to advanced Prostate CA - lower back pain, WL, bone pain
  • PSA produced by normal and cancerous prostate cells.
  • secreted into prostate fluid and semen, small amounts present in blood
  • due to altered architercture higher leakage into blood w prostate CA
  • Blood PSA inaccurate marker - CA can be present w/out increased PSA, PSA can be increased due to BPH/ prostatitis/ UTI
• International prostate symptom score (IPSS) - reliable accurate predictor of LUTS, self reported questionnaire QOL
• USS scan –> of renal tract and used to calculate the volume of the prostate, alongside investigation for urinary retention and hydronephrosis. Prostate > 30 ml considered enlarged.
• Urodynamic studies:
  
  • Uroflowmetry (pee into funnel calculates volume/ rate of flow/ length of time).
  • post voidal residual bladder volume USS/ catheter removal of remaining urine volume
  • Cystometric test - bladder emptied, then filled with warm water via catheter which also measure the pressure within the bladder, individual asked when need to urinate arises, may measure leak point measurement. Pressure flow study also possible, indivudal asked to urinate, pressure within bladder and flow rate calculated.
  • Pressure flow rate identifies bladder outlet blockage vs detrusor inactivity.
• Imaging –> if chronic retention/ recurrent UTI/Haematuria, renal insufficiency or urolithiasis.

Question 9

Describe the initial approach of management for the patient with urinary retention:

BPH management

Answer 9

• Minimal symptoms –> watchful waiting + reassurance, can have medication review, + moderate caffiene and alcohol
• moderate- severe symptoms –> Medication:
  
  • Alpha adrenoreceptor antagonist/ Alpha blockers –> Alpha 1a Receptors on prostate, bladder neck, urethra
    
    • Tamsulosin –> smooth muscle relaxant acting on bladder neck, can cause hypotension
    • Doxazosin - non selective alpha 1 receptor blocker - vasodilator
  • If they remain symptomatic –> 5 alpha reductase inhibitor - Finasteride
    
    • inhibits synthesis of dihydrotestosterone which stimulates prostatic growth (can take up to 6 months to feel symptomatic benefit).
  • Surgery –> If recurrent retention unresponsive to medication, recurrent haematuria, renal insufficiency, bladder stones.

Question 10

What are the surgical approaches to resect the prostate?

What are the complications of this procedure?

Answer 10

TURP - transurethral resection of the prostate:

Involves accessing the prostate through the urethra and shaving the excess prostate tissue using diathermy, aiming to create a wider space for urinary flow.

Other options:

Transurethral electrovaporisation of the prostate (TUVP)

Holmium laser enucleation of the prostate (HoLEP)

Open prostatectomy via abdominal or perineal incision

Complications:

• FIRES - failure to resolve symptoms, incontinence, retrograde ejaculation, erectile dysfunction, strictures. (+ bleeding and infection).

Question 11

Understand the common causes of urinary retention:

Urethral stricture Pathophysiology

Answer 11

• Urethral stricture = narrowing of the urethra, normally from scar tissue
• result of inflammatory, ischemic, or traumatic processes –> lead to scar tissue formation which contracts and reduces caliber of the urethral lumen, increased resistance to antegrade flow of urien
• Uncommon in men + rare in women.

Question 12

LO: Describe key questions from the history that differentiate causes:

Urethral stricture

Answer 12

• Few symptoms at the start
• decrease in force of stream
• spraying or double stream
• terminal dribbling
• frequency
• urinary intermittency
• urine infection
• decrease force ejaculation
• dysuria

Question 13

LO: Describe key findings from the examination which could help differentiate between causes

Urethral stricture examinations?

Answer 13

• General abdo
• palpate bladder
• DRE
• prostate

Question 14

Investigations for urethral stricture?

Answer 14

• max voiding flow rate
• cystoscope
• endoscopic evaluation
• radiography –> retrograde urethrogram (RUG) or antegrade cystourethrograms if suprapubic catheter –> document location and extent or stricture.
• ultrasonography –> evaluate stricture length, degree, depth

Question 15

Management of urethral strictures?

Answer 15

• treat UTI prior to surgical intervention
• surgical treatment –> indicated when patient has severe voiding sx/ bladder calculi/ increased postvoid residual/ UTI/ conservative management fails
  
  • urethral dilation (often requires repeats)
  • internal urethrotomy –> incising stricture transurethrally to release scar tissue
  • permanent urethral stent –> urethroplasty
• Open reconstruction –> complete excision of fibrotic urethral segment with reanastamosis

Question 16

What are the complications of a urethral stricture?

Answer 16

Residual urine –> bladder/ kidney/ prostate infection.

Risk of abscess

Question 17

LO: Understand the important causes of urinary retention:

Medication

What classes of medication and pathophysiology underlying them?

Answer 17

• Anticholinergics/ TCA’s –> parasympathetic which decreases detrusor contractility
• CCB –> decreased smooth muscle contractility
• antihistamine –> muscarinic receptor antagonists
• Botulinum toxin –>
• anaesthetics
• opiods –> increase sphincter tone of urinary bladder via SNS overstimulation
• alcohol –> alcoholic neuropathy
• Opiods + anticholinergic –> decreases bladder sensations

Question 18

LO: Understand common and important causes of urinary retention:

Damage to the nervous system?

Parkinson’s

Multiple sclerosis

Alzheimer’s

Answer 18

• Parkinson’s –>Associated with urgency related problems. Basal ganglia contributes to control of urination, underactivation of D1 receptors (which inhibit urination) –> failure to inhibit urination reflex
• Multiple Sclerosis –> underactive bladder/ outlet obstruction from destrusor sphincter dyssynergia (disturbance of muscular condition)
• Alzheimer’s disease –> UTI/ constipation/ Stroke or muscular disorder

Question 19

LO: understand common and important causes of urinary retention:

obstructive causes in women and pathophysiology + RF’s

Answer 19

• Cystocele
  
  • damage to pubocervical fascia in central/lateral areas, allows bladder to protrude into the vagina. Poor pelvic tone and weak pelvic ligaments
  • risk factors –> childbirth, menopause, coughing and straining, congenital CT disorders
• pregnancy
  
  • impacted retroverted gravis uterus = emergency
  • Risk of hydronephrosis of pregnancy (USS)
• Postnatal
  
  • sore in vaginal area, swelling, epidural altering sensation, injury to pelvic nerves
  • risk increased with prolonged labour, instrumental delivery, C -section
• fibroid
  
  • uterine leiomyomas, benign tumour of smooth muscle of myometrium which compress the ureters
  • subserosal types grow out from uterus and bulge into peritoneum
  • Intramural is w/in myometrium
  • submucusoal is inner mucosal uterine surface and into uterine cavity
  • RF’s: menopause, early puberty and obesity
• ovarian cyst
  
  • compression against bladder or obstructing the urethra
  • fluid filled sac in ovarian tissue
  • can be physiological –> infection/abscess
  • can be benign –> fibroma, dermoid cyst
  • malignant –> ovarian, endometrial

Question 20

LO: describe key questions from history and findings from exam to differentiate causes:

Gynaecological problems:

Cystocele

LO: What investigations would you do?

Answer 20

In history: sensation of vaginal pressure, incontinent, constipation, sexual dysfunction

In exam: vaginal protrusion

Investigations: Bladder USS

Question 21

Describe approach to management for patient with urinary retention:

Cystocele management

Answer 21

• Asymptomatic patients with grade 1 or 2 cystoceles do not usually require treatment –> watchful waiting and pelvic floor exercises
• patients with grade 3/4 require tx due to debilitating sx
• Reduce prolapse using vaginal pack/pessary or swab, ask patient to complete stress maneuvers to asses for stress urinary incontinence
• assess post void residual urine –> retention if volume above 100ml
• Urinalysis –> UTI rule out
• evaluate for bulge in urethra for possible urethral diverticulum (causes dysuria, dyspareunia, postvoid dribbling).
• Surgical fixation/ reconstructive surgery --> central cystocele reapproximates pubocervical fascia in midline, lateral defects -> vaginal attachments to pelvic sidewall reconstituted.

Question 22

LO: key qus from hx that differentiate between causes of urinary retention

Features of Fibroid history?

Signs on exam?

Answer 22

Key diagnostic hx features:

• Risk factors present = increasing age, black ethinicity, overweight
• often asymptomatic
• menorrhagia
• Pelvic pain or pressure
• period pain
• bloating
• urinary complaints - frequency
• constipation
• enlarged uterus

Key features on exam:

• irregular firm central pelvic mass

Question 23

LO: describe what investigations would be app to investigate causes of urinary retention

What investigations are appropriate for uterine fibroids?

What management?

Answer 23

Investigations:

• MSU - to exclude UTI
• USS
• endometrial biopsy
• hysteroscopy/ sonohysteroscopy/MRI/Laparoscopy

Management:

• majority uterine fibroids asymptomatic require no further investigation unless rapid growth/ suspicion malignancy
• tx symtoms, minimise persistence/recurrence of sx, address future fertility desires
• Medical tx: GnRH agonists - increased gonadotropin releasing hormone, induce low oestrogen state and fibroid shrinkage. Mifepristone- antiprogestogen, shrink fibroid. Levonorgestrel IUD - decrease bleeding in fibroid associated menorrhagia. NSAIDs for excessive bleeding and pain.
• Surgical tx: Myomectomy (surgical removal of fibroid). If fertility not desired hysterectomy.
• uterine artery embolisation for patients not suitable for hysterectomy and not desiring fertility.

Question 24

LO: features of history and exam

For Ovarian cysts

Answer 24

History:

• RF’s: Premenopausal women, history of early menarche, endometriosis, treatment for infertility, PCOS, tamoxifen or first trimester of pregnancy
• Pelvic pain
• bloating and early satiety

Exam:

Palpable adnexal mass (mass near uterus/ovaries/ fallopian tubes/ connecting tissues).

Question 25

**LO: what investigations are appropraite for ovarian cysts?**

Answer 25

* If abdominal exam reveals abnormalities: * ***Transvaginal ultrasonography*** --\> reveal enlarged ovary/portion of ovarian tissue, characterise size/consistency/location/ unilateral vs bilateral, determine if any pelvic free fluid * ***Fixed nodular mass --\> think malignancy*** * ***If malignancy suspected:*** * ***​Serum cancer antigen (CA-125) --\> levels \> 35U/mL warrants concern for ovarian cancer in post menopausal women. Not accurate in premenopausal women, associated with many benign conditions.*** * ***​C***ould consider MRI/USS/CT abdo pelvis

Question 26

LO: understand common and important causes of urinary retention: **What is the underlying pathology of prostate cancer?** **Define prostate cancer**

Answer 26

* **Definition: Prostate cancer: a malignant tumour of glandular origin situated in the prostate** * **Glandular cancers = adenocarcinomas (majority 95%)** * rates of cell division vs cell death no longer equal, leading to uncontrolled tumor growth --\> following initial transfomation even further mutations of tumour suppressor genes or oncogenes lead to tumour progression and metastasis. * when metastatic - transitional zone tumours can spread to bladder neck, peripheral zone to ejaculatory ducts and seminal vesicles. Penetration through prostatic capsule to perineural (surrounding nerve axons) or vascular spaces is late.

Question 27

LO: important features of hx and exam that differentiate causes of urinary retention: **Prostate cancer:** **1) key features in history** **2) key features of exam**

Answer 27

History: Risk factors ---\> increasing age (over 50 yrs), black ethnicity and family hx * LUTS (frequency, urgency, decreased stream) and retention * Haematuria * erectile dysfunction * Back and bone pain (advanced disease) * lethargy and anaemia * anorexia * weight loss * neurological deficit from spinal cord compression * lower extremity oedema or DVT from nodal compression of venous and lymphatic return **Examination features:** * DRE - Hard nodule, asymmetry, difference in texture, bogginess, change in texture overtime--\> PSA level * palpable lymph nodes associated with advanced metastatic disease * Note: most patients with prostate CA have normal DRE but abnormal PSA

Question 28

**What investigations are appropriate for prostate cancer?**

Answer 28

* PSA --\> initial investigation of choice, especially if over 50 yrs, requested, unexplained history or obstructive LUTS symptoms. * If \> 4 micrograms/ L or raised 0.75 micograms/L per year - sign of prostate cancer. * Note PSA not very specific --\> both positive and negative results can be false, most useful in monitoring progression of the disease and response to treatment. Also should be done prior to DRE (traditionally). Rises with age naturally. * Diagnostic investigation = Prostate biopsy: * Transrectual USS guided biopsy (TRUS)- ultrasound probe inserted in rectum and needle biopsy taken through rectal wall usually around 10 biopsies. * Transperineal approach allows more biopsies to be taken + higher sensitivity but takes longer and requires a GA. * Urinalysis (haematuria and exclude UTI) * Bloods: * U&E's renal function tests to exclude renal or bladder pathology/ UTI * FBC --\> anaemia * LFTs basline for therapy (antiandrogen therapy risk of hepatitis) * testosterone (baseline for androgen deprivation therapy) * Bone scan for patients with very raised PSA/high grade on biopsy, followed by plain xray * Pelvic CT or MRI if suspecting advanced disease, lymph infiltration and metastases

Question 29

Prostate anatomy: Outline What region is felt during DRE what is the vasculature (link to metastasis) and innervation?

Answer 29

* Prostate = size of walnut, 2/3rds glandular, 1/3 fibromuscular, surrounded by thin fibrous capsule (adventitia) * Histologically divided into three zones: * **Central zone** - surrounds ejaculatory ducts (25% volume) --\> ducts of the glands empty into prostatic urethra * **transitional zone** - located centrally, surrounds urethra (5-10% volume) - glands of transitional zone typically under BPH * ***peripheral zone - main body of the gland (65%) and located posteriorly.*** * ***​Peripheral zone is mainly the area felt against the rectum on DRE*** * ***ducts of glands of peripheral zone empty vertically --\> may permit urine reflux, higher incidence of inflammation in these compartments and linked to high incidence of prostate carcinoma*** * 4th zone - fibromuscular stroma - situated anteriorly in the gland smooth and striated muscle forms around internal and external urethral sphincter. **_Vasculature:_** * **Prostatic arteries** derived from **internal iliac arteries** (receives some branches from internal pudendal and middle rectal arteries) * venous drainage --\> **prostatic venous plexus --\> drains to internal iliac veins --\> via batson's plexus (valveless plexus connect deep pelvic veins to internal vertebral venous plexus).** **Innervation --\> inferior hypogastric plexus**

Question 30

management of prostatic cancer?

Answer 30

* If the prostate specific antigen level in men \> 50 yrs is \> 3 ng/mL or higher --\> refer urgently for 2WW pathway to urological cancer * If within normal range there is a low risk of prostate cancer, refer only if abnormal DRE or symptomatic. * If low risk --\> watchful waiting which includes regular GP appt and PSA testing. * If patients with confirmed prostate cancer but low prognostic risk can do active surveillance --\> repeated PSA/DRE and biopsies at regular intervals, if disease progresses they are eligible for radical treatment. * If higher risk prostate cancer (e.g. locally advanced, relapse after radiocal radiotherapy) radical prostatectomy which involves a number of options. * External beam radiotherapy (EBRT) directed at prostate * Brachytherapy --\> radioactive seeds implanted into the prostate, delivers continuous targeted radiotherapy to the prostate. * Hormonal therapy --\> antiandrogen therapy: prostate grows in response to androgens like testosterone, block hormones and therefore stop or slow prostate cancer growth. SE's of hot flushes, sexual dysfunction, gynaecomastia, fatigue and osteoporosis. * Bilateral orchidectomy = gold standard, surgical castration, removal of both testicles, option for locally advanced and metastatic prostate cancer, stops production of androgens. * Advanced -\> adjunctive and palliative --\> androgen withdrawal - bilateral orchidectomy or LHRH agonists e.g. ***goserelin- synthetic LHRH, leads to sustained reduction in testosterone)*** or, androgen blockade (e.g. bicalutamide) chemotherapy. * prevention: 5 alpha reductase inhibitor.

Question 31

What is the Gleason score?

Answer 31

When prostate is biopsied, 10-12 cores will be taken from different parts of the gland. The commonest and second most common tumour patterns are analysed and graded from 1 -5. Grade 1 well differentiated cancer Grade 2: moderately differentiated Grade 3: "" Grade 4: poorly differentiated cancer Grade 5 : anaplastic - poorly differentiated cancer Gleason score - sum of these two grades, can range from 2 to 10 Tumour grade is classified into either three risk categories on the basis of the Gleason Score: Low: 6 or less Intermediate : 7 High 8-10