Non-surgical management of stone disease

Non-surgical management of stone disease

This involves watchful waiting, medical expulsive therapy , SWL and stone dissolution therapy . Watchful waiting Patients with small (<5 /uni00A0 mm), non-obstructive, asymptomatic, lower pole renal calculi with preserved renal function may be kept on follow-up. Up to 90% of 4-mm stones and 50% of 6- to 10-mm stones pass spontaneously . Medical expulsive therapy Tamsulosin is an α -adrenergic adrenoreceptor blocker 1 ( α -blocker) that causes smooth muscle relaxation of the distal ureteric muscle. It can be used for distal ureteric stones larger than 5 /uni00A0 mm and to assist passage of fragments following SWL. Extracorporeal shockwave lithotripsy SWL is a non-invasive method introduced in 1980 by Christian Chaussy that allowed stones to be treated on an outpatient basis. Mechanism of action The stone is localised using either fluoroscopy or US or both. Then acoustic pulse waves are generated and focused on the stone. Stone fragmentation occurs as a result of mechanical stress caused directly by the energy transmitted by the incident shockwave and indirectly by the collapse of bubbles. The e ffi cacy of SWL reduces with an increasing number of stones and volume of stone burden. Steinstrasse is a German word meaning ‘street of stones’. It describes a row of closely gathered stone fragments that line the distal end of the ureter ( Figure 82.10 ). This occurs when the stone burden is high or when the stones are hard. These stones are usually asymptomatic and pass spontaneously; how ever, they may cause obstruction, requiring surgical interven tion. ‘Clinically insignificant residual fragments’ are residual stone fragments of 4 /uni00A0 mm in size or less after treatment that are expected to pass spontaneously . However, 20–40% of these fragments may not clear and for m a nidus for stone regrowth.