Lecture 15: Benign Diseases of the Prostate and Urinary Tract Obstruction Flashcards
definition of benign prostatic hyperplasia
BPH refers to the non-cancerous enlargement of the prostate gland, particularly the transition zone, leading to the compression of the urethra and subsequent lower urinary tract symptoms (LUTS).
BPH aetiology
The exact cause of BPH remains unclear, but age and hormonal changes, particularly the influence of dihydrotestosterone (DHT), play pivotal roles in its development. Genetic predisposition and lifestyle factors may also contribute.
BPH pathophysiology
BPH is characterised by the nodular overgrowth of prostatic tissue, predominantly in the transition zone. This growth impinges on the prostatic urethra, causing dynamic and static obstruction, leading to urinary symptoms.
signs and symptoms of BPH
- hesitancy
- weak stream
- frequency
- urgency
- nocturia
- sensation of incomplete emptying
BPH investigations
- urinalysis: MSSU, flow-rate study etc.
- international prostate symptom score (IPSS): assessing the severity of LUTS
- digital rectal examination (DRE): assess prostate size, consistency and the presence of nodules.
- prostate specific antigen (PSA) test: to rule out prostate cancer and guide further investigations.
- 2 week wait referral PSA levels are above age-specific range.
BPH management
- watchful waiting: for mild symptoms, particularly in older individuals.
- lifestyle modifications: fluid restriction, avoidance of caffeine and alcohol, and timed voiding.
- alpha-blockers (e.g. tamsulosin): for dynamic obstruction, provides symptom relief.
- 5-alpha reductase inhibitors (e.g. finasteride): to reduce prostate size.
- minimally invasive therapies: transurethral resection (TURP) of the prostate or laser prostatectomy.
- surgical intervention
describe the international prostate symptom score (IPSS)
- used to assess the severity of LUTS.
- score 20-35: severely symptomatic
- score 8-19: moderately symptomatic
- score 0-7: mildly symptomatic
how do alpha-blockers work to treat LUTS due to BPO?
- smooth muscle of bladder neck (i.e. intrinsic urethral sphincter) and prostate innervated by sympathetic alpha-adrenergic nerves (mostly alpha-1a subtype).
- alpha-blockers cause smooth muscle relaxation and antagonise the ‘dynamic’ element to prostatic obstruction.
how do 5alpha-reductase inhibitors treat BPE?
- 5alpha-reductase converts testosterone to dihydrotestosterone.
- blocks this conversion.
- reduces prostate size and reduces risks of progression of BPE (but only if > 25cc prostate)
- also reduces LUTS (to a lesser extent than alpha-inhibitors, combination therapy is the most effective)
what procedure is the gold-standard for surgical management of BPE causing BOO?
- transurethral resection of prostate (TURP) (except for prostate size > 100cc)
- can be done using glycine (monopolar TURP) or saline (bipolar TURP)
TURP complications
- bleeding
- infection
- retrograde ejaculation
- stress urinary incontinence
- prostatic regrowth causing recurrent haematuria or BOO
why can TURP not be performed if the prostate size > 100cc
High risk of intra-operative or post-operative complications including:
- bleeding
- fluid overload
- hypothermia
- TUR syndrome (triad of dilutional hyponatraemia, fluid overload and glycine toxicity) (only for monopolar TURP).
what are the complications of BPO?
- progression of LUTS
- acute urinary retention
- chronic urinary retention
- urinary incontinence (overflow)
- UTI
- bladder stone
- renal failure from obstructed ureteric outflow due to high bladder pressure
discuss the treatment of complicated BPO
most patients will require surgery:
- e.g. cystolithoplaxy and TURP for patients with BPO and bladder stones
alternative treatment options (e.g. for patients unfit for surgery):
- long-term urethral or suprapubic catheterisation
- clean intermittent self-catheterisation
complication of acute urinary retention
- UTI
- post-decompression haematuria
- pathological diuresis
- renal failure
- electrolyte abnormalities
features of pathological diuresis
- urine output > 200ml/hr
- postural hypotension (systolic differential > 20mmHg between lying and standing)
- weight loss
- electrolyte abnormalities
list the absolute indications for surgical intervention in patients with BPO
- refractory acute urinary retention
- chronic high-pressure urinary retention
- renal failure
- recurrent UTI
- failure of medical therapy to control symptoms
short-term urethral catheters (e.g. latex-based) should not be left in-situ for longer than?
4 weeks
long-term urethral catheters (e.g. silicone-based) should not be left in-situ for longer than?
12 weeks
upper urinary tract obstruction symptoms and signs
symptoms:
- pain
- frank haematuria
- symptoms of complications
signs:
- palpable mass
- microscopic haematuria
- signs of complications
upper urinary tract obstruction complications
- infection and sepsis
- renal failure (only if bilateral obstruction, single kidney or concurrent systemic upset e.g. sepsis, dehydration, nephrotoxicity)
if the upper urinary tract is obstructed, USS will show what?
- hydronephrosis
- hydroureter
- however, cause of obstruction may not be visualised (obscured by gas)
what type of imaging can be used for chronic unilateral upper urinary tract obstruction, esp. chronic PUJ obstruction?
MAG-3 renogram
management of upper urinary tract obstruction
- resuscitation
- investigations (including imaging)
- emergency treatment of obstruction (for unremitting pain or complications): percutaneous nephrostomy insertion or retrograde stent insertion
- treat underlying cause: e.g. stone, ureteric tumour, PUJ obstruction
clinical presentation of LUT obstruction
- LUTS: voiding and storage and urinary incontinence (overflow or urge)
- acute or chronic urinary retention
- recurrent UTI and sepsis
- frank haematuria
- bladder stones
- renal failure
- PV bleeding (for women)
what is the gold-standard standard investigation for renal colic?
CT-KUB (kidney, ureter, bladder)
what is the first-line treatment for 50 year old man with moderate LUTS, slightly enlarged prostate (25cc) and poor urinary flow?
alpha-blockers
treatment for 64 year old man with 2nd episode of acute urinary retention? He is already on an alpha blocker
TURP
35 year old lady with temperature 40 degrees celcius and right loin and flank pain. CT-KUB has shown a 10mm stone at upper right ureter causing severe hydronephrosis. Most appropriate treatment option?
nephrostomy insertion
