Practical limitations of bioresorbable membranes in the prevention of intra-abdominal adhesions.
BACKGROUND
Intra-abdominal adhesions are a significant source of postoperative morbidity. Bioresorbable barriers composed of hyaluronic acid and carboxymethylcellulose (HA/CMC) reduce adhesion formation by physically separating injured or healing peritoneal surfaces. To assess whether the efficacy of a physical barrier can extend beyond the site of application, we evaluated the effectiveness of an HA/CMC barrier in preventing adhesions distal to the site of placement.


METHODS
Adhesions were induced in rats by creating peritoneal ischemic buttons on either side of a midline incision. An HA/CMC barrier (Seprafilm Genzyme) was intraoperatively placed either under the midline incision, unilaterally over half the ischemic buttons, or bilaterally over all ischemic buttons. Control buttons received no HA/CMC. On day 7 adhesions were scored. In similar experiments, peritoneal fluid was collected at 24 h to assess the effects of HA/CMC on tissue plasminogen activator activity.


RESULTS
Placement of HA/CMC under the midline incision did not reduce adhesion formation to distal ischemic buttons (72 +/- 7%) compared to controls (80 +/- 8%). Unilateral placement of HA/CMC significantly (p < 0.05) reduced adhesion formation to those ischemic buttons over which the barrier was applied (35 +/- 7%) compared to both contralateral (83 +/- 9%) and control (80 +/- 8%) ischemic buttons. The bilateral application of HA/CMC also significantly (p < 0.05) reduced adhesion formation to all ischemic buttons compared to controls (22 +/- 7% vs. 66 +/- 7%, respectively). HA/CMC did not affect peritoneal tPA activity.


CONCLUSIONS
Effective adhesion reduction by the physical barrier HA/CMC appears to be limited to the site of application in this rat model. Despite the presence of a bioresorbable membrane at predicted sites of adhesion formation in the peritoneal cavity, adhesions readily form to distal unprotected sites.
Department of Surgery, Boston University School of Medicine, 88 East Newton Street, Boston, MA 02118, USA.
Rizal
R
Lim
Jonathan M
JM
Morrill
Ryan C
RC
Lynch
Karen L
KL
Reed
Adam C
AC
Gower
Susan E
SE
Leeman
Arthur F
AF
Stucchi
James M
JM
Becker
D000005:Abdomen; D020341:Absorbable Implants / Q000592:standards*; D000818:Animals; D013505:Digestive System Surgical Procedures / Q000009:adverse effects*; D004195:Disease Models, Animal; D008297:Male; D008567:Membranes, Artificial; D011183:Postoperative Complications / Q000473:pathology / Q000517:prevention & control; D051381:Rats; D017208:Rats, Wistar; D000267:Tissue Adhesions / Q000473:pathology / Q000517:prevention & control*
D008567:Membranes, Artificial