DEVICE FOR IN VITRO TRAINING OF SURGICAL SKILLS OR IN VITRO PERFORMING OF SURGICAL EXPERIMENTS

The present invention relates to a device for in vitro training of surgical skills, in particular microsurgical skills, or in vitro performing of surgical experiments.

In the relevant field of medicine it is widely acknowledged that surgeons in training should spend a certain period of time learning (micro)surgical skills in the laboratory before proceeding to (micro)surgery in the operating room. At present practice sessions in the animal laboratory are an obligatory part of neurosurgical training and as a result many experimental animals have been used to acquire the requisite skills for performing surgery successfully. However, the attitude towards animal experiments is changing, resulting in an increasing interest for the development of devices for in vitro training of surgical skills, which may replace the use of experimental animals. It is an object of the invention to provide a device of the type as mentioned above.

According to the present invention this object is achieved by a device of the type as described in the preamble comprising a housing having means for attaching human or animal tissue or a model thereof, means for fixating the attaching means in a desired position relative to the housing and means for supplying a fluid to the tissue or the model thereof. The technical measures of the device according to the invention effectively help to simulate operating conditions to such an extent that the amount of experimental animals otherwise necessary to acquire the desired surgeon's skills can be drastically reduced.

In a first preferred embodiment of the device the attaching means comprise hollow tubes, which can be connected to the fluid supply means. In the hollow tubes the two functions of attaching the tissue and allowing the fluid flow are combined in a cost effective manner.

According to another preferred embodiment the fixating means are slidable arranged on the housing to allow for tissues of different sizes to be fixed in the same way as they are presented to a surgeon in vivo. Preferably the housing comprises a rail for accommodating the fixating means. The rail allows selection of a desired fixation position over a relatively large area thus facilitating the use of tissue within a relatively wide range of sizes.

In a practical preferred embodiment the fixating means are arranged for clamping against part of the housing in order to make the fixation means easy to use.

According to an elegant preferred embodiment a device according to the invention comprises a base and a plate interconnected by means for adjusting the height of the plate relative to the base, wherein the attaching means, the fixating means and the fluid supply means are arranged on the plate. By adjusting the height of the tissue relative to the working height of the surgeon in training and his or her surgical instruments, such as a microscope,

the level of difficulty of the training can be changed. The height adjustment furthermore provides the opportunity to simulate different kinds of operating conditions that may be encountered in real patients.

In yet another preferred embodiment the housing defines a hollow space that is accessible from at least one side, wherein the attaching means are accommodated in the hollow space. Herein the operating space is narrowed down to the hollow space thus attributing to a realistic simulation of in vivo operating conditions. A further elaboration of this preferred embodiment further comprises fluid drainage means that are connected to the hollow space and provided with a stopcock. By means of the stopcock the level of fluid present in the hollow space can be adjusted as desired for an even more realistic simulation of in vivo operating conditions.

In a practical preferred embodiment the housing at least partly has a dark color, in particular a gray color. The dark color significantly enhances the visibility of the tissue thus optimizing the training conditions. The invention further relates to an assembly of a device according to the invention and a trestle with a trephination like hole that is arranged to be placed in front of a space defined adjacent the attaching means, which space is intended for placement of the tissue or the model thereof. By means of this assembly, preferably combined with the height-adjustable embodiment of the device, real (in vivo) operating conditions, wherein damaged tissue is found at different depths in a patient's body, can be optimally simulated.

The invention also relates to the use of the device according to the invention for training surgical skills, in particular microsurgical skills, or for in vitro performing of surgical experiments.

These and other features and advantages of the invention will be more apparent with a discussion of a preferred embodiment of the invention and reference to the associated drawings.

The invention will be explained in more detail with reference to the appended drawings, in which: Fig. 1A shows a schematic view of a device according to the invention;

Fig. 1 B shows the device shown in figure 1 with a blood vessel attached thereto; and Fig. 2 shows a schematic view of an assembly according to the invention of the device shown in figure 1 and a trestle.

Fig. 1A shows a schematic view of a device 1 according to the invention. The device 1 comprises a housing 2 defining a hollow space 3. The hollow space 3 has a lumen like shape and is accessible from above. In the lumen 3 means 4 are present for attaching tissue for training purposes or surgical experiments. Animal or human tissue can be used as well as

any models thereof. As an example a blood vessel may be used to train (micro)vascular surgery skills. For this purpose the attaching means comprise two hollow tubes 4 onto which the far ends of a blood vessel can be placed.

The attaching means 4 are arranged on fixating means for fixating the attaching means 4 in a desired position in the hollow space 3. The fixating means comprise two blocks 6 that are slidable arranged in the hollow space 3. The housing 2 is provided with a guide rail 7 on one or both of the sides thereof for accommodating two guiding elements 8 by means of a clamping screw 9. Each of the guiding elements 8 is attached to one of the blocks 6. The guide rail 7 extends over the full length of the housing 2, so allowing blood vessels with varying lengths to be attached.

The device 1 is especially suitable for use with the following types of tissue: 1) tissue comprising a cavity in which, in vivo, an internal pressure prevails, or 2) tissue that, in vivo, is run through by a fluid. Examples of a tissue of the first category are lungs, stomach, (gall)bladder etc. Examples of a tissue of the second category are blood vessels, lymphatic vessels, urinary passages, Fallopian tubes etc. In order to simulate in vivo operating conditions device 1 is provided with a flow system for supplying a fluid to the tissue. Fluid supply pipes 11 are, preferably detachably, attached to the housing 2, for instance by means of detachable blocks 6. The fluid supply pipes 11 are connected to the hollow tubes 4 in order to establish the desired internal pressure in any cavity of the tissue and/or allowing a fluid flow through any cavity of the tissue, by means of any kind of fluid suitable.

The drainage of fluid present in the hollow space, e.g. as a result of leakage, is provided for by drainage pipes 12. The fluid drainage pipes 12 are provided with stopcocks 13 which can be used to create any desired level of fluid in the hollow space 3 in order to simulate in vivo operating conditions. The housing 2 has a dark color, in particular a gray color, to make blood vessels having a naturally light color, better visible.

Two movable arms 14 are provided for facilitating attachment of the tissue. The detachable blocks 6 can be removed from the housing 2 and positioned on the arms 14. In this position the nipples 5 are easily accessible for attachment of the tissue thereto. The arms 14 are rotatably arranged on the device to facilitate the attachment of tissue with varying lengths. Once the tissue is attached the blocks 6 can be placed back in the housing 2 and fixated at any desired position.

Fig. 1 B shows the device 1 with a blood vessel 100 attached thereto. Device 1 comprises a base 10 and a plate 20 interconnected by means 16 for adjusting the height of the plate 20 relative to the base 10. The housing 2, complete with all the technical measures described above, is arranged on the plate 20.

Suitable height-adjusting means provide for evenly adjustment of the height. Preferably the height-adjusting means provide for a reproducible adjustment, such as a stepwise

adjustment. Mechanical height-adjusting means, such as a spindle 16, are very suitable for this purpose as they are reliable and cost effective.

Fig. 2 shows a schematic view of an assembly of a device 1 and a trestle 30 according to the invention. The trestle 30 is provided with a trephination like hole 31 that is arranged to be placed in front of the accessible side of the hollow space, i.e. above the housing 2 in front of the lumen 3. By adjusting the height of the plate 10 and thus of the tissue 100 present in its lumen 3 relative to the height of the hole 31 in the trestle 30 the training can be performed under varying simulated operating conditions.

It is noted that in a simpler embodiment (not shown) the housing 2 with the hollow space 3 may be left out. The plate 20 may then serve as housing or holder for the attaching means 4, 5, the fixating means 6, 8, 9 and the fluid supply means 11 , which may be directly arranged on the plate 20. A person skilled in the art will, where necessary, be able to adapt one or more of said means to this end after having read and understood the present disclosure. Different components of the device can be made of different materials. Suitable materials include plastic, such as PVC or Perspex, and rustproof metal, such as stainless steel. Using these materials the device is designed for cost effective production thus facilitating widely spread use.

Different variants of the preferred embodiment shown are possible within the scope of the invention. Although the preferred embodiment of the device has been described in the context of training vascular microsurgical skills, the invention is not limited thereto. The device according to the invention is universally suitable for training a variety of surgical skills. The device according to the invention is also very suitable for performing surgical experiments on various types of tissue or models thereof. A person skilled in the art will have no difficulty making small changes to the device, such as scaling it up or using other types of tissue/model attaching means, in order to render it suitable for use with other types of tissue than blood vessels or arteries.