Gross and histologic evaluation of 5 suture materials in the skin and subcutaneous tissue of the California sea hare (Aplysia californica).

Invertebrates are increasing in their importance in biomedical research and as popular display animals in public and private aquariums. The California sea hare (Aplysia californica) is 1 of the most widely used invertebrate animals in neurophysiology research. Because of its easily accessible ganglia and neurons and greater ease of rearing in captivity, Aplysia has replaced the squid giant axon in much neurophysiology research. Surgical techniques used in Aplysia research include probe placement within various nerves and ganglia.3,17,18 These techniques require surgical closure of the skin over the probe. An inflammatory reaction around a nerve can alter its excitability and associated research findings.5 Therefore, using a suture material that causes minimal inflammation and tissue reaction around the target nerve is prudent. Silk is perhaps the most commonly used suture material in Aplysia research,14,18,20 even though silk causes some of the greatest tissue reactions in several domestic and nondomestic species.11,13,24,26,28 As the popularity of invertebrates in the aquarium trade grows, an impetus is arising to provide more complete veterinary care for these animals. An increased demand for improved care, the environmental impact of collecting animals from the wild, and the cost of obtaining new animals have led many to pursue treatment of invertebrates over replacement.9,27 When surgery becomes necessary, suture choice can have a marked effect on incision healing: a suture that causes minimal inflammation and tissue disruption can facilitate the process. To this end, the current study evaluates the gross and histologic reactions of Aplysia to 5 commonly used suture materials: silk, monofilament nylon, polydioxanone, polyglactin 910, and poliglecaprone.