Urinary Tract Obstruction Flashcards
What is obstruction causing dilation of the renal pelvis and/or ureter called?
Hydronephrosis
Common causes of UTO in children.
Most likely congenital abnormalities or urethral valves.
Common causes of UTO in women.
In young women it is probably a pelvic tumour, pregnancy or stones.
Common causes of UTO in men.
Young men = stones
Elderly men = prostatic disease
Explain the pathophysiology of UTO.
Urine continues to form despite the obstruction.
This leads to progressive rise in intraluminal pressure, there is dilation proximal to the site of obstruction and compression and thinning of the renal parenchyma. This leads to reduced size of the kidney.
Acute obstruction is followed by transient renal arterial vasodilation succeeded by vasoconstriction.
Causes of UTO
Calculus, blood clot, sloughed papilla or tumour of renal pelvis, ureter or bladder.
Pelviureteric neuromuscular dysfunction, ureteric stricture, ureterovesical stricture, congenital megaureter, congenital bladder neck obstruction, neuropathic bladder.
Pelviureteric compression, tumours, diverticulitis, aortic aneurysm, retroperitoneal fibrosis, prostatic obstruction.
Clinical features of acute upper tract obstruction.
Loin pain radiating to groin. Can have sumperimposed infection +/- loin tenderness or an enlarged kidney
Clinical features of chronic upper tract obstruction.
Flank pain
Renal failure
Superimposed infection
Polyuria may occur due to the impaired urinary concentration.
Clinical features of acute lower tract obstruction.
Severe suprapubic pain +/- confusion (elderly).
Distended, palpable bladder containing around 600 ml
Dull percussion of bladder
Causes of acute lower tract obstruction.
Prostatic obstruction
Urethral strictures
Anticholinergics
Blood clots
Alcohol
Constripation
Post-op
Infection
Neurological
Clinical features of chronic lower tract obstruction.
Urinary frequency
Hesitancy
Poor stream
Terminal dribbling
Overflow incontinence
Distended palpable bladder +/- large prostate
Causes of chronic lower tract obstruction.
Prostatic enlargement
Pelvic malignancy
Rectal surgery
CNS disease such as transverse myelitis
Complications of chronic lower tract obstruction.
UTI
Urinary retention
Renal failure
Investigations for UTO.
Bloods - U&Es, Crea, FBC, PSA
Urine - Dipstick for blood and MC&S
Ultrasound
If there is hydronephrosis or hydroureter arrange a CT scan
Radionuclide imaging to do a functional assessment
Treatment of upper tract obstruction.
Nephrostomy or ureteric stent
(Stent may cause significant discomfort to patients and they should be warned before)
Alpha blockers can help reduce ureteric stent pain.