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Polyglycolic acid (PGA) mesh fabric is widely used for reinforcing injured tissues during surgeries. However, PGA induces chronic inflammation and adhesion. The purpose of this study is to develop PGA reinforcement "without PGA-induced adhesion." We developed a reinforcement fabric unified with PGA mesh and alginate foam. The antiadhesive effects of sodium alginate foam and calcium alginate foam were evaluated in rats. Sodium alginate foam unified with PGA mesh fabric exhibited strong effects that limit the extent and severity of adhesion, whereas calcium alginate foam unified with PGA mesh was less effective in preventing adhesion. In the sodium alginate group, fibroblasts and collagen fibers around implanted sites were sparse and the material degraded rapidly by macrophage ingestion. Fibroblasts and collagen fibers play a major role in adhesion formation and their excessive proliferation results in postoperative adhesion. Thus, inhibiting their increase is the key in preventing PGA-induced adhesion. The reinforcement that is composed of PGA mesh unified with sodium alginate foam strongly inhibited PGA-induced adhesion and showed excellent handling during surgery and could be easily applied with a one-step procedure.

Postoperative air leaks remain a major cause of morbidity after lung resection. This study evaluated the effect of a combination of polyglycolic acid (PGA) sheet and alginate gel on pulmonary air leaks in rats. Four pulmonary sealing materials were evaluated in lung injury: fibrin glue, combination of PGA sheet and fibrin glue, alginate gel, and combination of PGA sheet and alginate gel. With the airway pressure maintained at 20 cmH 2 O, a 2 mm deep puncture wound was created on the lung surface using a needle. Lowering the airway pressure to 5 cmH 2 O, each sealing material was applied. The lowest airway pressure that broke the seal was measured. The seal-breaking pressure in each experimental group was fibrin, 10.4 ± 6.8 cmH 2 O; PGA + fibrin, 13.5 ± 6.5 cmH 2 O; alginate gel, 10.3 ± 4.9 cmH 2 O; and PGA + alginate, 35.8 ± 11.9 cmH 2 O, respectively. The seal-breaking pressure was significantly greater in the PGA + alginate gel group than in the other groups ( p < 0.01). There were no significant differences among the other three groups. Alginate gel combined with a PGA sheet is a promising alternative to fibrin glue as a safe and low-cost material for air leak prevention in pulmonary surgery.

Postoperative intra-abdominal or intrathoracic adhesions sometimes cause significant morbidity. We have designed three types of alginate-based treatments using strongly cross-linked (SL), weakly cross-linked (WL), and non-cross-linked (NL) alginate with calcium gluconate. In rat experiments, we compared the antiadhesive effects of the three types of alginate-based treatments, fibrin glue treatment (a standard treatment), and no treatment against adhesions caused by polyglycolic acid (PGA) mesh (PGA-induced adhesions). The antiadhesive materials were set on the PGA sheet fixed on the parietal peritoneum of the abdomen. Fifty-six days later, the adhesions were evaluated macroscopically by the adhesion scores and microscopically by hematoxylin-eosin staining and immunostaining. We also tested the fibroblast growth on the surface of the antiadhesive materials in vitro. The antiadhesive effects of WL and NL were superior to the no treatment and fibrin glue treatment. A microscopic evaluation confirmed that the PGA sheet was covered by a peritoneal layer constructed of well-differentiated mesothelial cells, and the inflammation was most improved in the NL and WL. The fibroblast growth was inhibited most on the surfaces of the NL and WL. These results suggest that either the WL or NL treatments are suitable for preventing PGA-induced adhesions compared to SL or the conventional treatment.

Objective: Recently, linear staplers have been used frequently in thoracic surgery; however, air leakage from the staple line is still unresolved. Various buttress materials have been developed to prevent air leakage, but performance is still not satisfactory. We are therefore developing a new material, consisting of calcium alginate nonwoven fabric covered with sodium alginate sponge., Methods: Thirty-three beagle dogs were divided into 7 groups, and each underwent thoracotomy. Right middle lobe incision was performed with a linear stapler and 1 of the following buttress methods: group A, no buttress; group B, polyglycolic acid nonwoven fabric; group C, fibrin glue alone; group D, polyglycolic acid nonwoven fabric with fibrin glue; group E, polyglycomer sheet; group F, new alginate material; and group G, polyglycolic acid nonwoven fabric plus new alginate material. Burst pressures were measured under mechanical ventilation management., Results: Burst pressures were 12.0 ± 6.8 cm H(2)O in group A, 31.3 ± 6.6 cm H(2)O in group B, 13.9 ± 3.8 cm H(2)O in group C, 26.9 ± 2.8 cm H(2)O in group D, 24.8 ± 1.8 cm H(2)O in group E, 48.5 ± 4.9 cm H(2)O in group F, and 54.2 ± 12.4 cm H(2)O in group G. F and G group pressures reached the target of 40 to 50 cm H(2)O and were significantly higher than those of the 5 conventional groups (P < .0005), Conclusions: This alginate buttress should be effective for preventing air leakage during operations because it has both sealant and bolster effects working in conjunction., (Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Purpose: Postoperative intra-abdominal adhesion sometimes causes significant morbidity. The aim of this study was to compare the efficacy of our newly developed antiadhesive material, alginate flakes, to the most commonly used combination of hyaluronic acid and carboxymethyl cellulose film., Methods: Sodium alginate was formed into a gel, powder, or flakes. In the ex vivo study, these different alginate forms were attached onto pig skin and their antisolubility properties in saline and attachment stability were compared. In the in vivo study, a rat surgical adhesion model was used to study the properties of the alginates, and the rats were euthanized on day 14 after surgery. The efficacy of the antiadhesive materials was evaluated using an adhesion scoring system, and the locations that were treated with the antiadhesives were histologically examined., Results: In the alginate groups, the alginate flakes were superior with respect to the antisolubility and the attachment stability ex vivo as well as with respect to the antiadhesive efficacy in vivo. The adhesion score was almost the same as that observed in the alginate flake and cellulose film groups., Conclusions: We developed an alginate flake material and demonstrated its antiadhesive effects both ex vivo and in vivo. This is the first reported study using this flake-like material, which has a unique characteristic in that it can be applied by spraying in compressed air. Alginate flakes may therefore be especially useful in the field of laparoscopic surgery.