Resorbable laparoscopically deployable hemostat
The present invention is directed to a resorbable hemostatic nonwoven felt suitable for use in laparoscopic procedures and to methods for manufacturing said felt.
1. A method of manufacturing a resorbable hemostatic dressing comprising a single layer of three-dimensionally entangled nonwoven felt that is not separable into distinct layers by hand consisting essentially of oxidized cellulose fibers, wherein the felt has sufficient mechanical strength and flexibility to retain its structural integrity when deployed laparoscopically, said method comprising the steps of:
a) providing cellulose yarn having filaments of minimal twist;
b) forming a multi-yarn, single feed circular knitted cellulose fabric having minimal twist;
c) scouring the cellulose fabric;
d) oxidizing the scoured fabric;
e) pliabilizing the oxidized fabric;
f) de-knitting the pliabilized fabric to form a continuous strand having a crimp from about 5 crimps/inch to about 12 crimps/inch;
g) cutting the continuous strand to form staples, said staples having length from about 1½ to about 4¼ inches;
h) carding the staples into a carded batt; and
i) needle-punching and three-dimensionally entangling the carded batt to form a single layer non-woven felt.
2. The method according to claim 1 , wherein the steps of de-knitting and cutting are performed at low tension or minimal time at high tension.
3. The method according to claim 1 , wherein the step of de-knitting is performed without subsequent spooling and followed immediately by cutting.
4. The method according to claim 1 , wherein the carded batt comprises approximately 10 to 17 layers of carded web.
5. The method according to claim 4 , wherein the carded batt comprises about 12 layers of carded web.