A particular challenge presented in surgical instrumentation relates to the delivery of non-viscous or viscous solutions such as pharmaceutical agents, hemostatic solutions, anti-adhesives, wound-healing agents, analgesics, and the like. Non-viscous solutions can be sprayed into a surgery site using various instruments, but the solutions often drip off desired target site and pool in the body cavity before the active component can provide its intended benefit. For example, when bleeding occurs during surgery, it may obstruct the surgeon's vision, and increase patient risks from loss of blood. Thus, the surgeon may deliver an active hemostat component, such as thrombin compositions reconstituted in saline, or other tissue sealant to a bleeding target site. For example, a thrombin solution can be sprayed into an insufflated lumen using a laparoscopic tool, but the solution typically does not adhere to the bleeding target site and instead pools to the floor of the cavity. In contrast, a more viscous, tacky thrombin solution may adhere better to a bleeding target site, but such viscous solutions are often opaque and obstruct the surgeon's view. Hence, there remains a need for a fluid-delivery apparatus for use in surgery for administering a continuous infusion of beneficial fluids, such as thrombin solutions, optionally with the application of pressure, at the site in need.
Tissue sealants (or tissue adhesives) are used for providing hemostasis and closing incisions during many surgical procedures. Tissue sealants may include fibrin, comprised of thrombin and a fibrinogen material, although other multiple component materials are available. Tissue adhesives for making fibrin clots use different concentrations of fibrinogen solution in conjunction with a thrombin solution. Depending upon the percentages of fibrin and thrombin in each respective tissue adhesive solution, as well as the other components found in each solution, various factors impact the mixing and application of the components. These factors include viscosity of the initial fibrinogen and thrombin solutions and of the final mixed solution. When mixed together, thrombin and fibrinogen components usually coagulate very quickly, often yielding an adhesive gel within 10 or 20 seconds. When applied to a body's exterior, or when considerable access to the application site is possible, the tissue sealant's rapid coagulative properties are welcomed. Conversely, when a fibrin sealant is used during internal surgical procedures, such fast-acting properties may cause problems such as fouling or clogging of the applicator device during application.
Additionally, other considerations for laparoscopic instrument-based delivery of fibrin sealants include diameters or sizes of the fluid passages and the mixing compartment of the laparoscopic instrument, and mixing rate of the fibrinogen and thrombin solutions particularly in comparison to ejection rate if mixing occurs within the system. Typically, the individual components of the adhesive material are stored in isolated reservoirs.
There remains a need, however, for a fluid applictor system that is useful in surgery for delivering viscous fluids, or fluids that should be well-mixed for maximal activity. There is also a need for an applicator tip useful for both applying the fluid and holding it against the target site with a desired amount of pressure. Additionally, in particular cases, it may be beneficial to leave a biodegradable, bioadsorbable, fluid-laden applicator tip or pledget at a desired surgical site as a sustained release implant.