Thermal Conductivity of Surgical Metals
Many surgical procedures require the use of electrocautery instruments to control and stop bleeding intra operatively. Using these delicate instruments can be challenging. This is due to the tissue where the surgeon is operating will be at an elevated temperature. This is because of the exposure to high powered lights, and the related heat generated that is necessary for surgeons to see what they are doing. Instruments sticking to adjacent tissue or vessels can create serious complications. Constantly keeping the surgical field hydrated with non-sterile saline will always help. However, advances in metals with higher thermal conductivity ratings make surgeries much safer.
A variety of metals are used to conduct the electrical current used to stop bleeding. Thermal conductivity refers to the ability to transfer or conduct heat along a temperature gradient. This ranges from an area of high heat (the tips of the instrument) to an area of low heat (the tissue that the instrument is being applied to). The most common metals used are Stainless Steel (SS), Gold and Silver. These are either applied as a solid metal or applied in the form of a plate. This covers another metal at the area of application.
Metals
Silver has the highest thermal conductivity rating amongst these commonly used metals. It is also an ideal surface for the desired non-stick properties needed in surgery. With an average rating of 406 Watts per meter Kelvin (W/m K, K-Value), silver is the ideal surface for such applications. This is why silver is one of most used metals amongst these instruments since it is relatively inexpensive to produce compared to its other counterparts.
Gold is also used often for electrosurgery with a very high thermal conductivity rating. The average being 314 W/m K. Although Gold has many positive qualities, it is much more expensive than other materials. Since it has a high cost per oz, it is often used as a plate. This may have other unintended consequences as a result.
Stainless steel for years was the metal of choice because of its availability and low cost. However, with an average K-Value of 50.2 W/m K, it is not a very good option if non-stick is a priority. Often times Stainless steel is used as a base metal because of its rigidity with another metal plated over the top. This too has its inherent disadvantages.
Plating
Plating is a technique where a metal is overlayed on top of another metal. This is done to give the instrument a better K-Value. The necessity to clean and reprocess leads to oxidation. This breaks down the surface material (usually either Gold or silver) giving a lower thermal conductivity. When the outer surface bleeds through to the base (usually SS), it then has the conductive properties of the inferior metal. In addition, completely plating a small surface (sometimes as small as .3mm) requires you to ‘bend’ the non-stick metal to conform to its specification. With this, you create ‘weak spots’ in the metal. This will accelerate the breakdown of the non-stick surface, leading to an undesired performance. It is always best to use solid alloys in areas where K- Values are important.
ace bipolars, ace mis bipolars are all made with our proprietary solid silver alloy tips that will always remain non-stick for the life of the forceps. Exceptional manufacturing and the worlds best natural resources make for more sustainable solutions.
