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the dura mater is the outermost layer of the meningeal tissue . defects often arise from trauma or surgical procedures .
the commonly accepted approach is surgical repair of the dural defect to restore tissue homeostasis and barrier functions .
the repair must be fluid - tight to prevent , among others , postoperative cerebrospinal fluid ( csf ) fistula , infections , and pseudomeningocele .
since the 1890s , several materials have been used as dural grafts . at this point ,
the most commonly used substitutes are autologous grafts , e.g. fascia lata and galea - pericranium , or synthetic meshes .
acellular dermal matrices ( adm ) have been used in soft tissue reconstructions since 1995 , initially applied for treatment of burns .
chaplin and colleagues presented an experimental study evaluating the use of a porcine adm ( xenoderm ; acelity , san antonio , tx ) in a porcine model . in 2000 ,
warren and colleagues were the first to report their experiences on human adm ( alloderm ; acelity , san antonio , tx ) as a dural substitute in humans .
their experiences were promising and in accordance with a minor long - term study published later the same year .
we present two cases of dural defect repair using strattice pliable ( acelity , san antonio , tx ) , a porcine adm . to our knowledge , this has not previously been reported from other institutions .
a 60-year - old man with the birt  hogg  dub syndrome , and a history of five solid tumors , developed a malignant peripheral nerve sheath tumor in the sacral area .
it was initially treated with excision and radiotherapy ( 66  gy in 33 fractions ) . however , two years later , the malignant tumor recurred .
eighteen days postoperatively , magnetic resonance images ( mri ) revealed a csf accumulation superficial to the dura .
a second repair with a fascia lata autograft and a synthetic mesh was done . a few days after the second surgery , a new csf accumulation formed . with assistance from the department of plastic surgery ,
a suitable piece of strattice pliable was placed over the defect and with single - sutures , through drill holes , fixed to the sacral bone and by running sutures to the adjacent muscles .
after undermining the muscles superficial to the fascia , the soft tissue was closed layer by layer .
three months later , a computed tomography of thorax , abdomen , and pelvis ( ct - tap ) revealed new entrant bone and lung metastasis , and the patient was offered palliative radiotherapy .
the patient did not experience further csf - leakage and did unfortunately died two months later .
a 29-year - old woman diagnosed with arnold chiari malformations had an occipitocervical decompression surgery , due to progressive headache , in 2013 .
two years later , a second decompression surgery was done due to progressive ataxia and paraesthesia in her right arm . during the surgery ,
a titanium plate was attached to the remains of c1 , and a synthetic dural substitute was inserted .
postoperatively two mri scans within a month revealed accumulation of csf superficial to the dural repair site .
when the patient for the third time leaked csf from the wound , the leakage was sealed with porcine adm ( strattice pliable ) .
a suitable piece of strattice pliable was placed over the leak site and sutured , see figure 1 . before closing
a 60-year - old man with the birt  hogg  dub syndrome , and a history of five solid tumors , developed a malignant peripheral nerve sheath tumor in the sacral area .
it was initially treated with excision and radiotherapy ( 66  gy in 33 fractions ) . however , two years later , the malignant tumor recurred .
eighteen days postoperatively , magnetic resonance images ( mri ) revealed a csf accumulation superficial to the dura .
a second repair with a fascia lata autograft and a synthetic mesh was done . a few days after the second surgery , a new csf accumulation formed . with assistance from the department of plastic surgery ,
a suitable piece of strattice pliable was placed over the defect and with single - sutures , through drill holes , fixed to the sacral bone and by running sutures to the adjacent muscles .
after undermining the muscles superficial to the fascia , the soft tissue was closed layer by layer .
three months later , a computed tomography of thorax , abdomen , and pelvis ( ct - tap ) revealed new entrant bone and lung metastasis , and the patient was offered palliative radiotherapy .
the patient did not experience further csf - leakage and did unfortunately died two months later .
a suitable piece of strattice pliable was placed over the defect and with single - sutures , through drill holes , fixed to the sacral bone and by running sutures to the adjacent muscles .
after undermining the muscles superficial to the fascia , the soft tissue was closed layer by layer .
three months later , a computed tomography of thorax , abdomen , and pelvis ( ct - tap ) revealed new entrant bone and lung metastasis , and the patient was offered palliative radiotherapy .
the patient did not experience further csf - leakage and did unfortunately died two months later .
a 29-year - old woman diagnosed with arnold chiari malformations had an occipitocervical decompression surgery , due to progressive headache , in 2013 .
two years later , a second decompression surgery was done due to progressive ataxia and paraesthesia in her right arm . during the surgery
, a titanium plate was attached to the remains of c1 , and a synthetic dural substitute was inserted .
postoperatively two mri scans within a month revealed accumulation of csf superficial to the dural repair site .
when the patient for the third time leaked csf from the wound , the leakage was sealed with porcine adm ( strattice pliable ) .
a suitable piece of strattice pliable was placed over the leak site and sutured , see figure 1 . before closing
a suitable piece of strattice pliable was placed over the leak site and sutured , see figure 1 . before closing
despite more than a century of investigation and experimentation , research for the ideal substitute for dural repair continues . in spite of promising results using alloderm as a dural substitute , experiments with other adm products have , to our knowledge , not been reported . at our institution , we have great experience with porcine adm strattice for a wide range of reconstructive procedures , i.e. breast reconstructions , thoracic wall and abdominal wall reconstructions .
in addition , the adm has also been used for static reconstructions after facial nerve paralysis . moreover , the porcine adm ( strattice ) was chosen as the other available bovine adm ( surgimend prs ; tei biosciences inc . , boston , ma )
strattice pliable is the porcine counterpart to alloderm and widely used in breast reconstructions . here
it must be strong , be flexible , maintain structural integrity after suturing , be fluid - tight , be fully incorporative , not induce host response , not form adhesion to the underlying tissue , and act as a barrier to acute and chronic infections .
, the matrix contains only collagen fibers , elastin , hyaluronic acid , fibronectin , proteoglycans , and releasable growth factors .
all cellular components are removed in the process . among others , the properties of the adm
strattice pliable is flexible but has been shown to be both stronger and stiffer compared to alloderm . when suturing strattice pliable , deformity may hardly be considerable .
hence , a repair using strattice pliable will most likely be fluid - tight , if placed correctly .
previously it has been questioned whether incorporation of non - human grafts into the human body would induce a stronger immunologic / inflammatory response compared to allografts .
strattice pliable seems fully incorporated within six months . only during the first two weeks , moderate to significant inflammatory response consistent to normal wound healing
hence , only the first two weeks seems critical in regard to undesirable adhesion to the underlying tissue .
. however , warren and colleagues did not experience any cases of adhesion formation or rejection using alloderm . due to great similarity between allederm and strattice
another favorable feature of strattice is the supposed protective effect to microbial penetration of staphylococcus aureus and staphylococcus pyogene , two very common skin bacteria .
therefore , one may think that in case of infection , it does not necessarily lead to removal of the allograft , as it does not seem to get penetrated by bacteria .
this could be due to the neoangiogenesis that ensure the presence of immune cells inside the adm .
they managed to refrain from removing the adm , treating the infection with antibiotics only .
the use of vacuum therapy is shown to significantly increase blood flow and decrease the rate of infection in the treated area .
it can be hypothesized that combining vacuum therapy with implantation of an adm would decrease the incorporative process in a time perspective , due to higher infiltration rate . besides cost , and the above - mentioned requirements ,
autografts is not always available / obtainable opposite to allografts , and not to mention the absence of donor - site morbidity , e.g. pain , bleeding , and infection .   in our two cases , strattice pliable
was introduced after several attempts to repair a dural lesion using more traditional methods . despite this ,
but introducing adm at an earlier stage may however lower the total costs , by lowering the number of surgical interventions and days of admission . based on the published literature
, strattice pliable seems to meet the requirements for an ideal dural substitute . in our experience ,
abstractthe use of acellular dermal matrices ( adm ) for dural repair is very scantily described in the literature . 
 we report two cases of dural repair using porcine adm and a literature review . 
 adm and especially stratticetm pliable may be a useful alternative to other dural substitutes . 
 further evaluation would be favorable .