The bladder’s response to outlet obstruction is adaptive.
Obstruction induced changes in bladder function can cause symptoms on top of the direct effect of the obstruction itself.
The result is changes in detrusor contractility (obstructive LUTS) and changes in detrusor instability or compliance (storage LUTS).
There is also normal ageing related change to the bladder (reduced contractility and compliance) which compounds the problem.
Compensatory changes:
- Detrusor smooth muscle hypertrophy
- Increasing in bladder wall thickness
- Fibrosis and collagen deposition
- Above leads to increasing bladder contractility and higher voiding pressures
- Compliance may start to fall
Decompensation:
- Increasing fibrosis and collagen deposition
- Diverticula and trabeculations secondary to combination of hypertrophy and collagen
- Trigonal and inter-ureteric hypertrophy combined with increased intravesical pressures can lead to VUJ obstruction and obstructive uropathy
- Decreased bladder compliance causing overactivity and storage symptoms
- End stage is severely reduced contractility due to fibrosis and chronic stretch
