TiLENE® Guard

Implantation

Parastomal hernias are an ideal indicaton for laparoscopic procedures, as all work is done outside of the opened intestines. For this, three trocars are introduced into the abdomen at a distance from the stoma: a 10 mm trocar for the optic, and 10 mm and 5 mm trocars for the instruments. The trocars are arranged in a semicircle with the opening towards the stoma. Then begin with the preparation. Here, with the aid of electricity or ultrasound, the instruments are used to remove the parts of the large mesh from the gap around the stoma or parts of the small intestine which are attached inside this gap. The site then presents itself in such a way that the section of the bowel forming the artificial opening pulls into the gap in the abdominal wall.

For the next step, there are different procedures depending on the size of the gap. If the size of the gap around the bowel is not that large, the TiLINE Guard is introduced to the abdomen using the 10 mm trocar, placed around the bowel and spread across the gap. It is important that the mesh extends 5 cm in all directions beyond the edge of the hernia. In this position, the mesh is then firmly secured to the abdominal wall using staples or sutures. This way, the bowel is enclosed by mesh on all sides and the gap closed with mesh.

However, if the gap around the bowel is too large, an all-round overlap of the mesh of at least 5 cm is no longer ensured. In these cases, the gap around the bowel is first closed using a strong continuous suture thus achieving a reduction in the size of the defect. Subsequently, here, too, the mesh is positioned around the bowel and on top of the reducing suture.  Again, the mesh is secured to the abdominal wall using staples or sutures.

If necessary, a Robinson drain can be put into place at the end of the operation.

Titanisation

Chemical vapour deposition (CVD) is a process for the metallisation of complex components while at the same time achieving strong bonds. However, as this process involves temperatures in excess of 150°C, it is not an option for many prosthetic materials which would not be shape retentive at such temperatures (e.g. polypropylene).

For that reason, the titanisation of plastic implants takes place at low temperatures using a special plasma-coating process known as PACVD (plasma-activated chemical vapour deposition).

Plasma is the term used for an excited (ionised) gas. In that stage, atoms/molecules are highly energetic. However, plasma is not hot. In everyday life, we are familiar with plasma in fluorescent tubes. The electrically charged gas components emit light as the result of their highly energetic state, but the fluorescent tube remains cold.

In the titanisation process, gaseous titanium is introduced into the coating chamber as a precursor. By adding energy in form of plasma, the precursor is split into individual ionised atoms. These ionised titanium atoms have free electrons at their surfaces.

In addition to the precursor, the plasma also excites the surfaces of the plastic implants with the result that their surfaces also have free electrons. The ionised titanium atoms come into contact with the ionised surface of the implant resulting in the formation of covalent bonds with the free electrons. Covalent bonds are seen as the strongest of chemical bonds; the titanium is thus almost permanently bonded to the plastic.

This process creates a composite material whose surface is coated with an ultra-thin, approx. 30–50 nm (1 nanometre = 1 millionth of a millimetre), highly biocompatible layer of titanium. The coating is so thin that it appears to be transparent and is also highly flexible.

Because the titanium precursor is introduced in gaseous form, it reaches all parts of the plastic implant. As the result, the entire surface, including gaps in between complex shapes, is completely and evenly titanised.