Surgery – Instruments – Electrical application
Patent
1997-05-20
1998-12-01
Kamm, William E.
Surgery
Instruments
Electrical application
A61B 1736
Patent
active
058430792
DESCRIPTION:
BRIEF SUMMARY
This application is the national phase of international application PCT/SE94/00790 filed Aug. 29, 1994 which designated the U.S.
The subject invention concerns a device to stop bleeding in live human and animal tissue and to form a crust by means of a plasma jet. The invention relates to plasma surgery and more particularly to a new and improved plasma surgical technique of achieving coagulation or a hemostatic effect, i.e. desiccation and coagulation by weak supply of plasma jet power to a layer of tissue and intense supply of jet power to the fluid component of the biological tissue.
The purpose of the invention resides in plasma dynamic desiccation of a surgical site and in the creation in said site of an area of thermal necrosis at a rate highly exceeding the rate of medium or intense bleeding with the aid of direct application of a plasma jet having definite thermo-dynamic characteristics.
Plasma flow, laser irradiation and electrosurgery are methods used in surgery for clean-cutting purposes, for combined cutting and hemostasis effect as well as for obtaining hemostasis of a surgical wound.
The dominant reactions induced by intense energy application on tissue are thermochemical in nature as a result of the energy absorption by the biological object. The major part of the energy is converted into heat.
The thermal effect of the application of an intense flow of energy explains the character of the biological processes developing in tissue during and after the application.
An analysis of the biological and hemostatic effect of a concentrated plasma flow and irradiation on tissue has shown that an area of thermal changes (ATC) is formed therein which comprises several zones. As a result of intense power supply the surface of the tissue is desiccated and a spongy desiccated necrosis layer is formed on the tissue surface. The surface of the spongy layer is carbonized--Carbonized Spongy Layer (CSL). Due to a conduction mode of heat transfer a compact necrosis layer (CNL) is formed This layer forms between the spongy layer and the unaffected liveg tissue. The generation of a compact necrosis layer is a result of the thermal denaturation of protein occurring as temperatures rise above 56.degree. C.
From a medical-biological point of view the elimination of bleeding is obtained by creating an ATC and the level of hemostasis reliability depends on the size of the ATC and the time of its creation. In particular, the prior utilization of different methods of application (laser irradiation, plasma jet and electrosurgery) shows that positive hemostasis and lack of hazards during the healing process occur when the average thickness of the ATC is about 1.0 mm.
In the development work of the subject invention the characteristics of different layers in the area of thermal changes occurring when using conventional methods were carefully investigated.
Taking into consideration the bleeding rate when different necrosis layers were created in the area of thermal changes, fundamental disadvantages were found with respect to the various methods of thermal applications. Consequently, a need was felt for developing new methods for the purpose of achieving a high degree of efficiency in surgery on highly bleeding organs. Various such methods for creating characteristics of various zones of ATC will be discussed in the following.
While working on the prior technique emphasis has primarily been placed on the bleeding rate as a decisive factor when applying the method on high-rate bleeding organs. When the blood flow in tissue is heavy and the bleeding from a surgical incision is high, it is necessary to create an ATC ensuring that the vaporization rate of the liquid component is higher than the flow rate of the blood moving towards the incision. This means that the thermal energy developing inside the volume unit of the tissue as a result of the outer application must exceed the amount of power expended on vaporization of the volume unit of the blood flowing towards the incision.
To create a spongy desiccation layer on the surf
REFERENCES:
patent: 3991764 (1976-11-01), Incropera et al.
patent: 4788408 (1988-11-01), Wlodarczyk et al.
patent: 4855563 (1989-08-01), Beresnev et al.
patent: 4901720 (1990-02-01), Bertrand
Kamm William E.
Nikval International AB
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