Endoluminal Surgery of Rectum and Colon

The first endoscopic procedure for the rectal cavity was designed in 1980 [14] and has been in clinical application for more than 22 years. Figure 12.14 demonstrates the principle of the procedure [15]: Stereoscopic optic gives optimal view, gas dilatation allows good exposition of the rectal cavity, and the curved instruments allow a better access in typical positions of the tumor, so that optimal surgical performance is given.

This image with the three instruments also demonstrates the problem of integrating three instruments. When the active instruments of the surgeon are moved, they often collide with a third instrument, which normally is the suction device. Another disadvantage of this technique is that to prevent a collision, the suction device is often pulled backward and is therefore out of view. In this position, the suction device cannot remove the smoke from the cavity, so that the quality of view is diminished.

Together with ERBE (Tübingen, Germany), we have designed a highly complex combination instrument. This instrument by ERBE [16] has a specific design (Fig. 12.15): The curves at the tip allow optimal access to the area of the rectal wall and perirectal space. The curve close to the handle is necessary to prevent conflicts with optic and other instrument handles.

The instrument does include four different main functions: a needle for cutting; in the upper tube (dem

Fig. 12.13 A graphical demonstration of the Wolf combination instruments. Rinsing, suction, and coagulation by the tip are possible by the outer sheath of the combination instrument. The integrated hook allows sharp dissection. The tip can be pulled backward into the shaft of the combination instrument for unrestricted rinsing, suction, and coagulation

Fig. 12.13 A graphical demonstration of the Wolf combination instruments. Rinsing, suction, and coagulation by the tip are possible by the outer sheath of the combination instrument. The integrated hook allows sharp dissection. The tip can be pulled backward into the shaft of the combination instrument for unrestricted rinsing, suction, and coagulation

Fig. 12.14 The instrumentation for transanal endoscopic microsurgery (TEM) introduced into the rectal cavity; stereoscopic optic view above gives optimal view. Three curved instruments used in this application
Fig. 12.15 TEM-Erbe combination instrument. Through the upper tube the cutting needle can be pushed forward and backward. The tip of the upper tube allows coagulation, the lower tube suction

onstrated in blue) the channel for rinsing; at the tip of the upper tube a metal ring for coagulation; and in the lower tube a suction channel for the removal of fluids and smoke.

When cutting is performed, the needle has to be pushed forward; for coagulation, it must be pulled backward into the lumen. This task is completed by an electronic controlled pneumatic drive. When the yellow foot pedal is pressed, the pneumatic pushes the needle forward. When coagulation is activated or when for a short period no activation of the cutting electrode is performed, the needle is automatically pulled backward.

As in many situations, the combination does not only add different functions, but also giveesclear additional advantages. The fact that no change of instrument is necessary allows in the case of a bleeder no time loss, and suction is quickly possible, as is coagulation [17]. At the same time, the smoke generated by cutting or co agulation is automatically removed at the tip of the instrument, so the view during dissection is much better.

The combination instrument allows that during all the TEM procedure it is never necessary to use more than two instruments, which gives much more freedom in movement and as mentioned above, clear additional advantages. These advantages are specifically important in endoluminal surgery, where the lumen of the organ is restricting significantly the possibility to introduce additional instruments.

12.4 Full-Thickness Resection Device, the Concept of a New Device for Removal of Polyps from the Rectum and Descending Colon

More than 20 years ago, we worked on the design of a semicircular stapler, to be introduced into the TEM instrument [18]. The idea of this concept was to make full-thickness resections as simple as possible and to reduce possible complications by opening the perirec-tal spaces.

Years later, we were approached by Boston Scientific [19] with the aim to jointly develop a stapling device that allows full-thickness resection. After a long development period, we had the chance for experimental evaluation of a short and a long version of the new full-thickness resection device (FTRD). This device (Fig. 12.16) consists of a handle, which allows the insertion of two graspers, and a thin-lumen flexible endoscope. Attached is a flexible shaft with two different lengths, which allow either to reach the rectosigmoid junction or the splenic flexure. Into the head is integrated a resection chamber that includes a semicircular stapler for resection of full-thickness parts of the bowel.

Under the endoscopic view of the flexible endoscope, the healthy wall beside the tumor is grasped with special retraction forceps, which builds a fold of the bowel wall (Fig. 12.17). Using two graspers simultaneously, the tumor with the tumor-bearing wall is pulled inside the resection chamber. After localization of clear safety margins, the stapling function is activated, and with a knife, the semicircular resection is completed. The advantage of the FTRD device is that the bowel wall is already fused, and the vessels are occluded by the stapling mechanism before the wall is cut.

Fig. 12.16 The full-thickness resection device (FTRD). This instrument allows full -hickness stapling resection under en-doscopic control

Fig. 12.17 Bowel wall in the resection chamber

Fig. 12.17 Bowel wall in the resection chamber

This allows possible resection without any blood loss or risk of perirectal or pericolic infection. We have performed a series of animal experiments that allowed us to resect a bowel area of up to 6 cm in diameter, which means that tumors up to around 3 cm could be safely dissected with this device [20].

The development was stopped by Boston Scientific for different reasons. Our discussion dealt with the continuation of the program with the aim to make the stapling head thinner in diameter and more flexible, which would mean that the risk of moving upward into the descending colon would be reduced.

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