Tissue expander and method
First Claim
1. A soft tissue expander device comprising a flexible base and an expandable cover joined to the periphery of the base to define a fluid tight chamber between the cover and base, a fluid injection port communicating with the interior of the chamber for admitting fluid into the chamber to expand the cover, the cover including a first limited expansion portion expandable by initial fluid injected through the port and into the chamber from a collapsed position overlying the base to a taut position a distance above the base and a differential expansion portion adjacent said limited expansion portion expandable by said initial injected fluid from a collapsed position overlying the base said distance above the base, said limited expansion portion including limiting means preventing further expansion of such portion beyond said taut position by fluid injected into the chamber in addition to the initial injected fluid and said differential expansion portion including expansion means permitting further expansion of such portion beyond said distance whereby upon implantation of the base and collapsed cover beneath a soft tissue layer of skin and subcutaneous tissue injection of fluid through the port and into the cavity first expands both the first and second cover portions together with the tissue overlying such portions said distance above the base and then expands the second cover portion together with the tissue overlying the second cover portion only beyond said distance to form a differentially expanded tissue flap.
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Accused Products
Abstract
A soft tissue expander device adapted to be implanted beneath a layer of skin and subcutaneous tissue and filled with fluid to differentially expand the overlying tissue including methods for differentially expanding soft tissue and treating male pattern baldness.
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Citations
46 Claims
- 1. A soft tissue expander device comprising a flexible base and an expandable cover joined to the periphery of the base to define a fluid tight chamber between the cover and base, a fluid injection port communicating with the interior of the chamber for admitting fluid into the chamber to expand the cover, the cover including a first limited expansion portion expandable by initial fluid injected through the port and into the chamber from a collapsed position overlying the base to a taut position a distance above the base and a differential expansion portion adjacent said limited expansion portion expandable by said initial injected fluid from a collapsed position overlying the base said distance above the base, said limited expansion portion including limiting means preventing further expansion of such portion beyond said taut position by fluid injected into the chamber in addition to the initial injected fluid and said differential expansion portion including expansion means permitting further expansion of such portion beyond said distance whereby upon implantation of the base and collapsed cover beneath a soft tissue layer of skin and subcutaneous tissue injection of fluid through the port and into the cavity first expands both the first and second cover portions together with the tissue overlying such portions said distance above the base and then expands the second cover portion together with the tissue overlying the second cover portion only beyond said distance to form a differentially expanded tissue flap.
- 17. An expander device adapted to be implanted beneath a soft tissue layer of skin and subcutaneous tissue and to differentially expand the overlying skin and tissue in two steps, comprising a flexible base and an expandable cover joined to the peripheral edge of the base to define a fluid tight chamber between the cover and base, a fluid injection port communicating with the interior of the chamber for admitting fluid into the chamber to expand the cover, the cover including a limited expansion portion and a differential expansion portion adjacent said limited expansion portion, said limited expansion portion including means preventing expansion beyond a taut position and the differential expansion portion including means permitting expansion beyond the taut position of the limited expansion portion, the device having a collapsed position when implanted with the cover overlying the base, a partially expanded position where fluid injected through the port and into the chamber expands the limited expansion portion of the cover a distance above the base to the taut position and the differential expansion portion of the cover a corresponding distance above the base, and a fully expanded position where further fluid injected through the port and into the chamber moves the differential expansion portion a further distance above the base beyond the limited expansion portion without further moving the limited expansion portion above the base whereby the skin and subcutaneous tissue overlying the cover are differentially expanded.
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24. A surgical method of expanding and applying soft tissue by use of a soft tissue expander device having an expandable cover comprising the step of:
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(a) Separating a layer of skin and subcutaneous soft tissue connected to surrounding skin and soft tissue from underlying support tissue to form a pocket; (b) Placing a collapsed soft tissue expander device in the pocket with the cover of the device facing the separated tissue layer; (c) Forcing the cover against the separated tissue to expand the tissue layer substantially uniformally away from the underlying tissue; (d) Retaining a first portion of the cover in the expanded position and further forcing a second portion of the cover against the overlying portion of the separated tissue layer to further expand such overlying portion only; (e) Collapsing and removing the soft tissue expander device from the pocket; (f) Severing edges of the expanded layer from surrounding soft tissue to form a differentially expanded tissue flap; and (g) Flattening and applying the tissue flap to a recipient area larger than the area of the separated layer. - View Dependent Claims (25, 26)
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27. The method of treating male pattern baldness using a pair of soft tissue expander devices comprising the steps of:
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(a) Forming pockets on both sides of the head between the skull and adjacent layers of hair-bearing occiputal and hair-bearing temporal scalp; (b) Placing a soft tissue expander device in each pocket; (c) Differentially expanding the devices in the pockets to form a differentially expanded hair-bearing scalp layer above each device with the length of the expanded temporal scalp being greater than the length of the expanded occiputal scalp; (d) Collapsing and removing the soft tissue expander devices from the pockets; (e) Removing the bald scalp area between the expanded scalp layers on each side of the head; (f) Severing the upper, anterior and posterior edges of the expanded scalp layers from the adjacent scalp tissue to form flaps; (g) Drawing the severed flaps upwardly around the head so that the flaps join at the center line and cover the former bald area; and (h) Applying the flaps to underlying tissue. - View Dependent Claims (28, 29, 30)
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- 31. A soft tissue expander device adapted to be implanted collapsed beneath a soft tissue layer of skin and subcutaneous tissue, the device comprising flexible wall means defining a fluid impervious chamber, and an injection port communicating with the interior of the chamber for admitting fluid into the chamber to expand the chamber, said wall means including an expandable cover in contact with the layer of skin and subcutaneous tissue when the device is implanted, the cover including a first limited expansion portion expandable by initial fluid injected through the port and into the chamber from a collapsed implantation position to a taut position above the collapsed position and a second differential expansion portion adjacent said limited expansion portion expandable by said initial injected fluid with the limited expansion portion above the collapsed implantation position, said limited expansion portion including limiting means preventing further expansion of such portion beyond said taut position by further fluid injected into the chamber in addition to the initial injected fluid and said differential expansion portion including expansion means permitting further expansion of such portion by said further fluid whereby fluid injected through the port and into a chamber of an implanted device first expands both the first and second cover portions together with the tissue overlying such portions and then further expands the second cover portion together with the tissue overlying the second cover portion only to form a differentially expanded tissue flap.
Specification