Managing the consequences of obstruction

Nowadays, it is widely accepted that bladder outflow obstruction (BOO) is not the only cause of lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH), the aetiology is multifactorial. It is increasingly recognised that the bladder as well as the central and peripheral nervous system may be directly involved in the development of LUTS. This review focuses on the consequences of BOO for the bladder. As a response to obstruction, the bladder compensates for the progressive increase of pressure overload with detrusor hypertrophy. Initially, this response is sufficient to maintain detrusor contractility and bladder emptying, but sustained obstruction may finally induce (irreversible) bladder damage with subsequent risk of detrusor failure. It is therefore important, in the treatment of LUTS/BOO, not only to relieve LUTS, but also to prevent or reduce alterations in the bladder, such as the development of smooth muscle cells hyperplasia, collagen deposition, detrusor ischaemia and reperfusion injury. Limited data are currently available that evaluate the effect of LUTS/BPH therapies on disease progression at the bladder level. Reduction of the bladder mass has been observed following BPH surgery, confirming the results obtained following the relief of experimental obstruction in the rabbit and mini-pig models. Preliminary clinical data suggest a similar effect of the α1-adrenoceptor (AR) antagonist tamsulosin in BPH patients. In the management of LUTS/BPH, it is no longer sufficient to focus treatment on the prostate, but protection of bladder function has also become an important target for treatment. Patients should be treated soon enough to prevent the effect of BOO on the bladder and to lower the risk of BPH adverse events. The question remains as to when treatment should be initiated and for how long it should be maintained to prevent permanent bladder damage. This makes the pharmacological treatment of obstruction and its consequences a fascinating new approach in the management of LUTS/BPH patients.