Telescopic metal dilator

The track into the collecting system is formed by serial dilatation. This can be done using either serial plastic fascial or telescopic metal dilators under fluoroscopic guidance. We prefer metal dilators, as they maintain continuous tamponade, thus preventing bleeding into the collecting system. 

Fig. 6.8 Flexible telescoping sheaths mounted on inner metal dilator sheaths. Sheaths 1,3, and 5 from the left are seen apphed over the metal dilator. (Photograph conrtesy of Cook Pacemaker Corp.)...

The EVOLUTION mechanical dilator sheath set (Cook Vascular) is composed of an inner plastic sheath with a threaded metal tip and an outer telescoping polymer sheath. The inner sheath has a stainless steel tip at its distal end, and no electrical energy supply is required. This sheath is mounted on a pistol capable of mechanically rotating the sheath. Multiple sheath sizes are available 7 F, 9 F, 11 F, and 13 F. A shortle version, with a shorter sheath length, is also available. Although this sheath has the capability of dissecting through all types of tissues, even calcified adhesions, there are only limited experiences reported in literature [20, 21], and some complications related to this tool are described [22] (Fig. 4.13). 

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