Surgicel: its fate following implantation.

Surgicel, a local haemostatic gauze, is claimed to consist of oxidised regenerated cellulose. It is a polyanion, the functional unit of which is termed polyanhydroglucuronic acid. The ability of tissues to absorb Surgicel and its inherent haemostatic properties have been extensively investigated. This study was undertaken a) to determine the time required for absorption of Surgicel from implantation sites in the chest wall muscles of rats, and b) to establish mechanisms for its removal. Data derived from sequential uronic acid assays, histochemistry using the stain alcian blue, and transmission electron microscopy of implanted Surgicel were interpreted to reveal that Surgicel consists of at least two active components. These are a soluble uronic acid component which is lost after 6 h, and a fibrous component which persists. The latter material resembles Surgicel in the electron microscope and is still evident at the implantation site at 48 h post-implantation. Moreover, Surgicel can be characterized in vitro into at least two components according to its solubility under dissociative salt conditions (4M guanidinium chloride). A residual fibrous material could then be hydrolysed with 0.3N sodium hydroxide. We postulate that the absorption of the former salt soluble uronate in vivo is by early degradation and/or systemic clearance, whilst removal of the fibrous material requires phagocytosis.