| 摘要 |
A dilator (1, 13, 22) is provided of the general type comprising a radially resilient tabular lattice (2) supporting a f1exib1e tabular sheath (3) such that the tabular lattice and sheath can be constricted to reduce the diameter thereof with a consequent elongation of the tabular lattice. The dilator has means (5, 2a, 14, 15, 23, 25) associated with both its proximal end (4, 16, 24) and distal and (6, 12, 26) for decreasing the diameter of both ends against the resilience of the dilator. The means for decreasing the diameter of the proximal and of the dilator is a generally a drawstring (5, 15, 23). The means for decreasing the diameter of the distal and may be either a series of radially extending elements (2a) connected to the distal end of the lattice and connected to each other by a leading end cap (7) carried by a control tube or a second drawstring arrangement ('14, 25) wherein, for installation purposes, the drawstring or drawstrings pass through a small diameter control tube (17, 27). |
