Example of the use of 3D video technology in rectal resection

Introduction

Barmherzigen Brüder Regensburg Hospital is, with 900 beds, the largest Catholic hospital in Germany and the teaching hospital of the University of Regensburg.
The department of general and visceral surgery has 78 beds and performs approximately 3,000 operations per year. The department has a senior physician, a senior proctologist, six attending physicians, five specialists and 12 medical assistants.

With the exception of organ transplants, it performs the full range of general and visceral surgical operations. Our hospital has been certified by the German Cancer Society as an intestine center, pancreas center and oncology center. Our hospital has been designated by the German Society for General and Visceral Surgery as a center of excellence for the surgical treatment of pancreases and as a center of excellence for the surgical treatment of malignant peritoneal diseases.

The department is recognized nationally for the treatment of malignant peritoneal diseases. Around 120 operations in peritoneal cancer are performed every year. During these operations, as part of what is known as cytoreductive surgery, multivisceral resection is required in addition to the peritoneal peritonectomy. Following the operation, the abdomen is rinsed with a hyperthermic chemotherapy solution.

Another therapy specialization is colorectal cancer. In the intestine center, we operate on around 100 primary cases with colon cancer and approx. 60 primary cases with rectal cancer every year. Where possible, modern minimally invasive surgical techniques are used for these operations. So, for example, around 60% of the rectal cancer operations are carried out using minimally invasive techniques.

The department has an MIS theater with fixed integrated 2D video tower and three additional permanently installed HD monitors. In addition, there is a portable 2D video tower so laparoscopic operations can be carried out in two operating theaters at the same time. In May 2014, a 3D video tower manufactured by the company Aesculap (EinsteinVision®) was purchased as a third laparoscopy unit. This is also equipped with an HD 2D camera so it can also be used as a fully-fledged laparoscopy unit.

Use of the 3D video technology at Barmherzigen Brüder Regensburg hospital

The 3D tower can be used for all current laparoscopic operations. Due to the improved three-dimensional representation imaging, during routine operations such as a laparoscopic cholecystectomy, TAPP hernia or laparoscopic gastric sleeve, less experienced surgeons in training also benefit from the simplified display of the anatomy thanks to the zoom and accurate representation of anatomical structures. In addition to improved comfort for the surgeon, this may also lead to a reduction in the duration of the operation and prevent mistakes. ^{[1], [6]}

From our point of view, the stereoscopic imaging has the advantage, in complex laparoscopic operations such as distal pancreatectomy, ^[2] gastric resection or laparoscopic Roux-en-Y gastric bypass in particular, of reliable and intuitive spatial orientation with improved depth perception. Even experienced laparoscopic surgeons can benefit from this during such operations. ^{[5], [6]}

After the training required according to the German medical devices act, a surgeon can immediately cope with the new technology so, in our opinion, almost no learning curve is required. Other departments report that it took five operations to learn how to handle the technology. ^[3]

In laparoscopic operations that require sutures and intracorporeal knot tying, such as laparoscopic fundoplication, rectopexy, TAPP or gastric resection with anastomotic sutures, the advantages relate, above all, to the three-dimensional orientation in space, above all when maneuvering without a direct spatial reference, for example when aligning the needle during laparoscopic suturing. ^[4]

For a comfortable spatial impression, a minimum distance must be kept between the laparoscope and the object. Therefore, during 3D laparoscopic adhesiolysis in abdominal adhesions, in TEP hernia surgery or transanal minimally invasive surgery (TAMIS), the 3D view is fairly cumbersome. In the event of distorted three dimensional images, it helps to switch to 2D mode occasionally or to operate primarily in 2D. ^[1] The use of the 3D video tower is described below in rectal resection by way of example.

Rectal resection in general

Following comprehensive TME in rectal resection, the prognosis of rectal carcinoma improves dramatically. The local relapse rate can be significantly reduced by the complete removal of the surrounding fatty tissue with intact mesorectum. ^[10] Thanks to the now anatomically correct dissection, there is now also lower blood loss, and maintenance of the autonomic nerves leads to a better functional outcome in terms of bladder and sexual function. ^{[8], [9]}

With increasing use and experience of MIS, it was soon widely used in the surgical treatment of colorectal carcinoma. ^[11] In addition to the cosmetic effect, other advantages of MIS include lower use of pain medication, earlier bowel function, and shorter hospitalization with quicker post-operative recovery. For colon cancer, an equivalent oncological standard with regard to radicality and long-term survival was quickly demonstrated. ^[12]

The evaluation of laparoscopic rectal resection in terms of radicality and long-term survival is still controversial. The data from the Color II study published to date demonstrate, at least, equivalence between MIS in rectal cancer in terms of radicality and long-term survival. ^[13]

According to the current German S3 guidelines, colon cancer and rectal cancer can be treated laparoscopically with the same oncological outcome as with open surgical techniques, provided the surgeon has the appropriate expertise and selection is appropriate.

The laparoscopic rectal resection

As a result of the literature data, patient advantages and patient desires mentioned above, rectal cancer is increasingly being operated on laparoscopically in increasing numbers at every anatomical level. At our clinic, the figure is 50 %, with a significant upward trend, so that sooner or later the lap. rectal operation will also be a training operation.

The 3D video tower is being used more and more in laparoscopic rectal resection. While in the previous model, the camera head was bulky and heavy and had to be supported by a special supporting arm, the new 3D camera head is significantly easier to manage and small and, in terms of size and weight, similar to a conventional 2D camera head so it can now be held by the medical assistant with no problems. We use a 30 degree camera, which allows the perspective to be adjusted electronically 30 degrees down and 30 degrees up.

The patient is placed in a modified lithotomy position with the legs extended along the axis of the torso, the tower with the 3D unit is on the left, at around the same height as the patient's back, the 3D monitor is turned so that the surgeon standing to the right of the patient and the cameraman are looking at the monitor at a right angle. The surgeon and assistant wear special 3D glasses. The surgical nurse stands between the patient's legs and generally looks at the 2D screen that is turned towards her and does not wear the glasses.

Once the skin has been disinfected and sterile drapes positioned, the 3D camera, which is two separate cameras and covered and handled with a tube (10 mm diameter), is connected to the disposable visual bearing and is thus sterile packaged. The light conductor is integrated into the system and does not have to be separately delivered.

From our perspective, the system with the sterile camera cover has two separate advantages. The 3D camera has a longer lifespan as the required sterilization procedures are omitted. Secondly, the same camera can be used again in a subsequent operation on the same day without having to perform sterilization procedures so it is not necessary to have several expensive 3D cameras available.
The first trocar is inserted paraumbilically either through minilaparotomy under visual control or using a Veress needle after the usual safety tests have been carried out. The subsequent trocars are then applied at the usual sites (right middle and lower abdomen, lower left abdomen) under visual control. During this process, the camera can be switched electronically to a 30 degrees upwards view. This means that the trocars can be positioned as normal under visual control.

Start the dissection from the right at around the level of the promontory. After making an incision in the visceral peritoneum, a very important surgical step is started, namely the mobilization of the upper mesorectum with display and preservation of the dorsal hypogastric nerves.

The mesorectum is a cylindrical three-dimensional structure that is displayed three-dimensionally with superb depth of field using the 3D camera. This scenelike view enables the relationships to the environment to be shown directly, with the hypogastric nerves also shown more clearly in reference to the mesorectum so that they can be preserved more safely.

The next stage of the operation is the radical transection of the inferior mesenteric artery. For this, the mesosigmoid is further separated from the right from the prerenal fascia (Gerota's fascia) laterally and cranially to the left and, where possible, to the inferior edge of the pancreas and the left ureter displayed. The circumferential dissection of the inferior mesenteric artery takes some getting used to if the 30 degree perspective cannot be rotated mechanically upwards to the right – as is normal in 2D laparoscopy. However, this can be achieved after a quick learning curve. The inferior mesenteric artery can be shown in three dimensions and radically transected between clips. Further cranial preparation and transection of the inferior mesenteric artery between endoclips at the inferior edge of the pancreas.

Completion of the mobilization of the sigmoid colon and descending colon from the lateral side up to the spleen and complete mobilization of the left colic flexure. For this the lesser sac is opened by surgical removal of the greater omentum from the left transverse colon. Again, the stereoscopic representation helps provide reliable orientation in space between the transverse mesocolon, pancreas and posterior gastric surface.

Dissection in the pelvis minor with completion of the TME. Start presacrally progressing laterally on both sides. In full TME, the dorsal dissection in the pelvic floor in the region where the rectum changes section and rises ventrally is made easier by rotating the camera and switching to a 30 degree upwards view. The three-dimensional depth perception improves the anatomical visualization, which is oriented to the outline of the mesorectum. For TME dissection up to the area where the mesorectum runs circularly. The rectum is removed in the pelvic floor region immediately orally of the sphincter with an endo-GIA.

A minilaparotomy with Pfannenstiel incision, oral removal of the intestine with tying of a counter-pressure plate, repositioning of the intestine and anastomosis through descending colorectostomy side to end or colo-pouch-anal anastomosis. Connecting the pressure plate to the transrectally lowered pin is made easier with 3D view, as is the suturing of the posterior vaginal wall in infiltration and resection. The operation is completed by attaching a double protective ileostomy to the preoperatively marked site.

Conclusion

The initial experiences with the 3D laparoscopy tower are positive. It is easy to manage with a very short learning curve. The 3D laparoscopy tower has been integrated into our daily work and is used in both common routine operations as well as complex oncological operations.

The main advantage is the three-dimensional spatial display with improved depth perception. This means that anatomical structures, for example nerves in the lesser pelvis, can be visualized better along their course and with regard to neighboring structures and that some stages of the operation, for example, intracorporeal suturing, are made significantly easier. As a result, both less experienced and more experienced laparoscopic surgeons benefit from this technology.

Our experiences so far in rectal resection with total mesorectal excision were described as an example. Whether there is an improvement in the quality of the outcome in addition to improved comfort for surgeons should be further investigated in clinical studies.