Process and apparatus for harvesting tissue for processing tissue and process and apparatus for re-injecting processed tissue

There is disclosed a method and apparatus for harvesting tissue using a cannula having a diameter of from 0.5 to 4.0 mm and of a length of from 25 to 20 cm to access by minimally invasive techniques a host to withdraw autogenous tissue processed to remove loose fat and/or fragmented tissue. Thereafter, the resulting tissue substrate is morcellated to form particulate tissue of a particle size of from 1 to 200 .mu.m. The particulate material is thence passed through screens having opening sizes of from 1 to 100 .mu.m to form a material of a size for introduction into a syringe of from 16 to 30 gauge for implantation in the host. The processed tissue may be admixed with extenders, gelling agents and the like.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a process and apparatus for harvesting tissue for 
processing tissue and process and apparatus for re-injecting process 
tissue. 
2. Description of the Prior Art 
It is known to harvest tissue from one part of a body and transplanted same 
to another part of the body to correct genetic and acquired defects. 
Tissue is harvested using cutting devices designed to form sheets of 
material, such as skin or drilling devices to create plugs, such as bone. 
A major drawback to the use of harvested tissue obtained with cutting or 
drilling devices is that the graft material obtained from such processes 
has to be harvested with dimensions that exactly fit the defect to be 
filled. Additionally, the material must be either meshed in the case of a 
skin graft or trimmed in the case of a bone graft to fit into the defect. 
Such drawbacks limit the use of harvested tissues to defects that can be 
filled with the available harvested material or that can be accessed in an 
open surgical field. 
There are various methods and apparatus for cutting and removal of tissues 
from mammals; however, each of such methods and apparatus suffer from one 
or more deficiencies. For example, in U.S. Pat. No. 4,265,231, there is 
illustrated a cannula attached to an adaptor connected to a drill for 
making passageway through the bone; however, there is no description as to 
how the bone material can be collected and processed. In U.S. Pat. No. 
4,541,423, there is illustrated an apparatus for drilling a curved hole 
having a flexible shaft; however, again, no removal and processing of cut 
bone or tissue. U.S. Pat. Nos. 4,589,141; 4,603,694; 4,751,922; and 
4,832,683 also illustrate an apparatus or process for removal; however, no 
processing of tissue is disclosed. In U.S. Pat. No. 5,269,785, there is 
illustrated a percutaneous removal apparatus having a flexible drilling 
shaft with a cutting tip mounted on the shaft, a power source for 
transmitting the shaft and the container for collecting one or more 
components of harvested tissue is disclosed and wherein the harvested 
tissue fragments are subsequently implanted using surgical techniques. 
OBJECTS OF THE INVENTION 
An object of the present invention is to provide an improved process and 
apparatus for harvesting soft and hard tissue. 
Another object of the present invention is to provide an improved process 
and apparatus for harvesting soft and hard tissue to obtain extra cellular 
matrix for use as graft materials. 
Still another object of the present invention is to provide an improved 
process and apparatus for harvesting soft and hard tissue to obtain viable 
cells for transplantation. 
A still further object of the present invention is to provide an improved 
process for harvesting soft and hard tissue wherein the harvested tissue 
is processed for introduction into the host donor by injection through a 
needle. 
SUMMARY OF THE INVENTION 
These and other objects of the present invention are achieved by a process 
and apparatus for harvesting tissue using a cannula having a diameter of 
from 0.5 to 4.0 mm and of a length of from 25 to 20 cm to access by 
minimally invasive techniques a host to withdraw tissue to be processed to 
remove loose fat and/or fragmented tissue. Thereafter, the resulting 
tissue substrate is morcellated to form particulate tissue of a particle 
size of from 1 to 200 .mu.m. The particulate material is thence passed 
through screens having opening sizes of from 1 to 100 .mu.m to form a 
material of a size for introduction into a syringe of from 16 to 30 gauge 
for implantation in the donor host. The processed tissue may be admixed 
with extenders, gelling agents and the like.

DETAILED DESCRIPTION OF THE INVENTION 
In the present application, the terms used have the following meaning: 
"Autogenous tissue" means transferring a tissue or part of an organ by 
transferring it into a new position in the body of the same individual. 
"Allograft tissue" means tissue obtained from another individual of the 
same species. 
"Implant" means material either solid or liquid used to fill a tissue 
defect or augment a defect. 
"Chemically-modified autogenous tissue" means any autogenous tissue that 
has been modified by exposure to a solvent or condition that results in 
the formation of covalent bonds. 
"Connective tissue" means any soft or hard tissue containing one or more of 
the following compounds selected from the group consisting of collagen, 
proteoglycans, elastic tissue, structural glycoproteins and cells. 
In accordance with one embodiment of the present invention, there is 
provided a minimally invasive method for harvesting soft and hard tissues. 
Accordingly, referring to FIG. 1, a cannula 10 having a diameter of from 
about 0.5 to 4.0 mm and a length of from about 2.5 to 20 cm is introduced 
into the host subject from which tissue is to be withdrawn for processing 
to autogenous tissue. After filling of the cannula 10 using a detachable 
motion control unit 12 connected by an adaptor 14, the tissue is withdrawn 
from the cannula 10 into a process unit 16, referring to FIG. 2. The 
tissue is thereafter introduced into a processing vessel (not shown) and 
contacted with a physiological amount of saline or phosphate buffer to 
remove any loose fat or fragmented tissue. 
The thus partially treated tissue is then fragmented by morcellation in a 
processing unit using a spinning blade wherein the blade rotates at from 
100 to 10,000 RPM's and subjected for processing time period of between 20 
seconds to 5 minutes until the partially treated tissue is uniformly 
fragmented into pieces with an average particle size of from 1 to 200 
.mu.m. The thus fragmented tissue is passed through a screen mesh having 
openings of from 1 to 100 .mu.m until there is collected a material of 
uniform consistency. The thus processed tissue is introduced into a 
syringe and thereafter introduced as a graft material by injection into 
soft or hard tissue defects through a needle of the syringe having an 
opening of from 16 to 30 gauge. 
In another embodiment of the present invention, 1.0 to 10 ml of harvested 
soft tissue from one site is mixed with from 1.0 to 10 ml of harvested 
tissue from another site and introduced into the process vessel and 
contacted with physiologic saline or phosphate buffers to remove loose fat 
or fragmented tissue. The thus treated mixture is morcellated as 
hereinabove discussed for a period of from 3 seconds to 5 minutes to form 
a uniform mixture to be injected by a syringe. 
In still another embodiment of the present invention, 1.0 to 10 ml of 
harvested tissue is introduced into the processing unit and contacted with 
physiologic saline or phosphate buffers to remove loose fat or fragmented 
tissues. Thereafter, of from 1.0 to 100 ml of an extender: such as 
albumin, collagen, gelatin; synthetic polymers, such as poly(lactic) acid; 
and plant polymers, such as cellulose is admixed with the processed 
tissue. In addition to such extenders, other physiologic extenders may be 
added including saline, blood components, concentrated blood components, 
thrombin, phosphate buffered saline, growth factors and hormones. 
In still further embodiment of the present invention, other tissue 
components, such as blood components, may be admixed with the process 
autogenous tissue to form a gel, such as by admixing 0.1 to 3.0 ml of 
concentrated fibrinogen solution with of from 1.0 to 3.0 ml of processed 
soft or hard tissue. The mixture is permitted to gel with from 10 to 1000 
units per ml of thrombin. Additionally, other gelling agents, such as 
alginates and tissue adhesives can be used to form the solid gelled graft 
materials. 
In still another embodiment of the present invention, the processed soft or 
hard tissue is formed into autogenous implants in solid form used to 
repair soft and hard tissue. Accordingly, 1.0 to 3.0 ml of processed 
tissue is admixed with 1.0 to 3.0 ml of concentrated fibrinogen solution 
and 10 to 1,000 units per ml of thrombin. The resultant mixture in the 
process unit 16 is introduced into a mold 18 of predetermined size of 
from, for example, 1.0 to 10 cm in length referring now to FIG. 3. The 
gelled tissue is permitted to incubate at 20 to 100% relative humidity at 
temperatures between about 20.degree. to 30.degree. C. for between 5 to 60 
mins. 
In accordance with the present invention, the implant material does not 
stimulate an immune response and persist at the site of implantation. For 
example, 0.1 to 1.0 ml of harvested and processed tissue may be injected 
through a needle having a diameter of 16 to 30 gauge into the dermis with 
no concomitant associated inflammation with the results persisting for 
from 6 months to 10 years depending on the implantation site. 
FIG. 4 illustrates the introduction of extended harvest material 20 
together with extended material 22 being introduced into a syringe 24 from 
the process unit 16. 
EXAMPLES OF THE INVENTION 
The following examples are illustrative of an apparatus of the present 
invention, and it is understood that the scope of the invention is not to 
be limited thereby. 
Example 1 
The cannula having a hollow shaft of a diameter of 2.0 mm is inserted into 
a 2.0 mm incision made in the skin and inserted into the dermis above the 
fat layer. One ml of dermis is removed and the tissue is placed in a 
processing unit for morcellation for a period of 5 minutes. The 
morcellated tissue is collected in a 5.0 mm syringe and passed through a 
series of mesh screens beginning with 100 micrometers down to 0.5 
micrometers until the resulting material easily passes through an 18 gauge 
needle. 
Example 2 
One ml of dermis is harvested as described in Example 1 and admixed with 
1.0 ml of physiological saline (0.9% W/V sodium chloride). The mixture is 
morcellated as described in Example 1 until the morcellated tissue easily 
passed through an 18 gauge needle. 
Example 3 
Ten ml of blood is collected from a host in a sealed sterile tube 
containing sodium citrate providing a final citrate concentration of 1% 
(W/V). The blood sample is centrifuged at 600 g for 20 min. and plasma 
removed with a sterile syringe and transferred to another sterile sealed 
tube. The plasma is then frozen at -15.degree. C. for 24 hours and thawed 
at 4.degree. C. Thereafter, the thawed plasma is centrifuged for 5 min. at 
3000 g. The supernatant is discarded and the resulting solid material 
re-solubilized in 1.0 ml of distilled water. The resolubilized material is 
admixed with 1.0 ml of processed tissue as discussed in Example 1 together 
with 200 units of bovine thrombin. The resulting mixture is placed on a 
flat surface and allowed to form a sheet of 200 micrometer in diameter and 
incubated at room temperature for 10 min. 
Example 4 
A processed dermis as described in Examples 1 and 2 is injected into 
depressed skin areas using a 2.0 ml syringe with an 18 gauge needle. The 
depressed areas are overcorrected by introducing sufficient graft material 
to elevate the defect area beyond the height of the surrounding skin. 
The graft materials of the present invention overcome many of the 
difficulties in the prior art and have a combination of advantageous new 
properties. The autogenous tissue is biocompatible and persistent, and 
does not require skin testing as is necessary with the use of processed 
animal collagen. Still further, carefully processed harvested tissue 
results in maintaining of cell viability for successful implantation. 
The filler materials described in the present invention overcome many of 
the problems associated with the use of foreign materials as well as 
tissue cultured materials. More significant materials of the present 
invention may be processed during an operation or medical procedure or 
prepared and then stored for use at a future time. The filler materials 
include both cells as well as components of connective tissue, and the 
product is persistent when implanted and as hereinabove discussed. The 
process of the present invention permits harvesting autogenous tissue, 
extension and processing of such tissue in the operating room or an 
outpatient facility or a surgi-center in order to be able to immediately 
re-introduce the material into the host as an injectable or solid state 
filler. 
The autogenous process tissue of the present invention are especially well 
suited for the repair of soft tissue injuries as distinguished from prior 
attempts using autogenous tissues requiring lengthy processing which 
modifies the chemistry of the connective tissue macromolecules or 
devitalizes the cellular components. 
While the invention herein has been described in connection with an 
exemplary embodiment thereof, it will be understood that many 
modifications will be apparent to those of ordinary skill in the art and 
that this application is intended to cover any adaptations or variations 
thereof. Therefore, it is manifestly intended that this invention be only 
limited by the claims and the equivalents thereof.