To rehydrate AlloDerm^® Regenerative Tissue Matrix

When preparing to use AlloDerm^® Tissue Matrix in the operating room (OR), the following rehydration procedure should begin early enough to allow for adequate rehydration prior to intended implantation.

For best results when rehydrating AlloDerm^® Tissue Matrix, use liberal amounts of warmed saline solution (up to 37°C) in a two-step bath with light agitation.

Normal rehydration of AlloDerm^® Tissue Matrix is usually accomplished in 10-40 minutes, depending on thickness.

Equipment required:

• Two sterile dishes (e.g., kidney dishes)
• Sterile normal saline or sterile lactated Ringer's solution that is sufficient to completely submerge the product
• Sterile atraumatic forceps

Step 1:

• Tear open outer foil bag at the notch and remove inner peel-pouch. (Keep both the foil bag and peel-pouch OUT of the sterile field.)
• With AlloDerm^® Tissue Matrix tissue aseptically removed from its peel-pouch packaging (backing left on), place in first bath of saline solution.
• For tissue less than 21cm², use at least 50ml of rehydration fluid per sheet. For tissue greater than 21cm², use 100ml per sheet.

Tip: Warming saline up to 37°C and using gentle movement of AlloDerm^® Tissue Matrix in the solution speeds the rehydration process. However, do not heat saline above 37°C.

Tip: When rehydrating multiple pieces, ensure that the pieces are not touching or clumping together as this may slow down the process. Use multiple bowls if necessary.

• Submerge the tissue completely and soak for a minimum of 5 minutes or until the backing separates from the AlloDerm^® Tissue Matrix.

Tip: Keep AlloDerm^® Tissue Matrix fully submerged by weighing it down, e.g. with sterile forceps.

Step 2:

• Using sterile gloves or forceps, remove and discard the backing once it separates from the tissue. Then, aseptically transfer the tissue to a second bath filled with at least 50ml of rehydration fluid per graft.
• Submerge completely and soak until the tissue is fully rehydrated (thicker grafts may take up to 40 minutes).

Tip: Keep AlloDerm^® Tissue Matrix fully submerged by weighing it down (e.g., with sterile forceps).

When AlloDerm^® Tissue Matrix is fully rehydrated, it is soft and pliable throughout. At this stage, it is ready for application to the surgical site. AlloDerm^® Tissue Matrix may be aseptically trimmed to required dimensions. Important: use AlloDerm^® Tissue Matrix within four hours of rehydration.

Considerations:

• If you are having a problem with rehydration, gently wipe/rub (with a sterile gloved hand) both sides of AlloDerm^® Tissue Matrix to remove any excess cryoprotectant that may be creating a barrier between the AlloDerm^® Tissue Matrix and the saline.
• If not completely rehydrated, AlloDerm^® Tissue Matrix will appear to be of uneven thickness and have a mottled appearance.
• Animal studies have shown that implanting dry AlloDerm^® Tissue Matrix induces a mild inflammatory response.
• Antibiotics may be added to the second rehydration solution.

To determine orientation of AlloDerm^® Tissue Matrix for an implantation procedure

AlloDerm^® Tissue Matrix has two distinct sides: the basement membrane and the dermal surface. In an implant procedure, the dermal side should rest against the most vascular tissue to speed up the revascularization process.

How to distinguish each side of AlloDerm^® Tissue Matrix

• Physical appearance
• Basement membrane side: rough and dull
• Dermal side: smooth and shiny
• Distinguishing sides using the blood test


• Add a drop of blood to both sides and rinse with rehydration solution. Since blood readily infiltrates the vascular channels within the matrix, the dermal side will look bright red. The basement membrane side will look pink.

• AlloDerm^® Tissue Matrix has the natural elasticity of human skin.
• In order to establish the shape and dimension required for the graft, AlloDerm^® Tissue Matrix should be expanded intraoperatively.
• When used for hernia repair, AlloDerm^® Tissue Matrix should be sutured intraoperatively under significant tension after proper rehydration; based on surgeons' experience, removing the laxity of AlloDerm^® will expand the surface area coverage of each piece used by up to 50%.
• For example, a 16x20cm piece of AlloDerm^® Tissue Matrix may expand to 19x25cm after complete rehydration and when significant tension is applied intraoperatively.


• The expected expansion of each graft should be considered when determining the size and number of grafts. Thicker graft sizes (those designated “X-Thick”/2.06 - 3.30mm) will expand less than the “Thick” grafts (0.79-2.03mm).


• AlloDerm^® Tissue Matrix is available in a variety of sizes and thicknesses, enabling surgeons to choose the proper product for each procedure. (Most abdominal wall repairs—especially the more complex procedures—tend to require the larger pieces of AlloDerm^®.)

Preparing to implant AlloDerm^® Tissue Matrix

• AlloDerm^® Tissue Matrix can be shaped with scissors or scalpel and rolled or folded to necessary thickness.
• When AlloDerm^® Tissue Matrix is ready, store in the second saline wash until surgical site is prepared.
• Important: Use AlloDerm^® Tissue Matrix within four hours of rehydration.

To prepare the surgical site for AlloDerm^® Tissue Matrix implantation

• AlloDerm^® Tissue Matrix can be applied to open surgical sites allowing primary closure over the top of the tissue.
• When replacing an integumental membrane, orient AlloDerm^® Tissue Matrix with the basement membrane side toward the cavity.


• If primary closure is not possible, orient AlloDerm^® Tissue Matrix with the  dermal side toward the most vascular surface and the basement membrane side exposed.


• If AlloDerm^® Tissue Matrix is covering an avascular bed, orient the dermal side  against vascularized flaps or tissues.

Plane of placement

AlloDerm^® Tissue Matrix can be used as an underlay or an onlay. AlloDerm^® Tissue Matrix is useful in for challenging procedures in patients with a range of comorbid conditions that may increase the risk of complications if a synthetic material is used (e.g., obese, smoker, diabetic, malnutrition, etc.).

In addition, AlloDerm^® Tissue Matrix is increasingly being used in challenging hernia repair—particularly in those cases where infection, hernia recurrence, and significant loss of abdominal fascia have traditionally made the surgeon’s job especially difficult.

Suturing AlloDerm^® Tissue Matrix

• Nonabsorbable 2-0 suture (e.g., Prolene) is recommended.
• Use either a running or interrupted stitch, according to preference.
• When used for hernia repair, AlloDerm^® Tissue Matrix should be sutured under significant tension after complete rehydration.

Before use, physicians should review all risk information and essential prescribing information which can be found in the AlloDerm<^® Regenerative Tissue Matrix Instructions for Use.