Damage In Surgery

BACKGROUND OF THE INVENTION

All surgical disciplines are concerned with the repair of damaged tissues and vessels. Damage can be the result of direct trauma to the body or as part of a surgical procedure in which there is a separation of normally continuous tissue such as in vein or artery anastomoses. Regardless of the cause, proper repair of the tissue or blood vessel is an essential step in the positive outcome of surgery.

The joining of separated tissues has principally been performed by suturing or stapling in which the skilled hands of the surgeon stitch or staple the separated tissues together. This procedure not only requires significant skill but also is a slow, tedious process, particularly if extensive repair is required.

Suturing

In particular, laser adhesives are difficult to apply to separated tissues. They are either in the form of semi-solids (e.g. fibrinogen) or liquid (e.g. albumin or blood). As a semi-solid, the product must be cut into strips and placed at the weld site. Quite often the solid strip will move during application requiring time consuming repositioning. Additionally, the strip may shrink when exposed to the laser beam and weld only a portion of the tissue. The unwelded portion may be large enough to permit the passage of blood. This requires the use of additional strips of welding material and time consuming repeat operations.

Liquid laser adhesives are disadvantageous because they can run off of the weld site and thus may also require repeat applications. In addition, conventional laser adhesives made of protein materials, such as fibrinogen, often form rigid welds which reduce the flexibility of the welded tissues, particularly welded blood vessels. If the vessel is subjected to normal pressure fluctuations which occur during the cardiac cycle, such as the unclamping of the blood vessel or when the patient moves suddenly, the weld can rupture causing internal bleeding and related

Additionally, the presence of multiple charged or uncharged side chains may be advantageous to facilitate gel formation, production of a high viscosity composition, and/or interaction between molecules in the composition and/or tissue. Low molecular weight, small chain polysaccharides require higher concentrations to produce viscous, gel-like materials, and tend to be less desirable. One of the preferred polysaccharides is hydroxypropylmethylcellulose which is preferably used in a sterile aqueous solution. As a sterile solution it may be formulated to have a molecular weight exceeding 80,000 daltons and a viscosity of at least about 4,000 centipoise. See, for example, Thomas J. Liesegang et al., "The Use of Hydroxypropyl Methyl Cellulose in Extracapsular Cataract Extraction with Intraocular Lens Implantation", Am. J. Ophth. vol. 102, pp 723-726 (December,