An optical navigation system was adapted for abdominal surgical purposes, The feasibility and potential usefulness was investigated in 24 patients with a colorectal tumor or diverticulitis. The information from a preoperative CT scan was integrated in the real time live video images. Instruments were marked and identifiable during the navigation. All patients underwent a laparoscopic colorectal resection.
The feasibility of the system was established. The accuracy of finding the tumor [21 patients]was evaluated, as well as the identification of the tumot borsers,the optimal placement of the trocarts, the accuracy of localization of the ureters [19 patients], the accuracy of localization of arterial vessels supplying the bowel, and the number of conversions and positive margins. The feeling of safety of the surgeon was evaluated during the procedure.
The feasibility of the system was established, and the images were accurate within a 0,5 cm. All 21 tumors were accurately foung by navigation. Extension and ingrowth were visible on the navigation images [3 patients]. All ureters except for one were easily found using the navigation system. Th placement of the trocarts was changed by a mean of 1,9 cm using the navigation system. When the arterial phase was scanned preoperatively an accurate imaging of the arteries was obtained draining the bowel part to be resected [5 patients]].
No patient was converted during the procedure to an open version. There were no positive tumor margins in the 21 patients with colorectal cancer.
The feeling of safet during the procedure increase by a mean of 28% as assessed by the operating surgeon using the navigation system.
Conclusion: The navigation system is a useful addition to laparoscopic colon resectioni. The reduced sense of feeling , and the increased problem of orientation by 2D images during the laparoscopic procedure can be translated into an advantage by being able to see through the tissues and identifying landmarks and the tumor. These are otherwise not visible to the surgeon. The 3D information of a preoperative CT scan which is integrated in the real time live video images during the procedure appeared to be accurate and reproducable.
Localization of the tumor is often diffiult, but was easy and reliable by using the navigation system. Potential complications like transecting the ureter or leaving positive margins are less probable by using the navigation system.
The surgeon is able to able to feel more secure about the orientation of the instruments in relationship to the tumor and other important structures. Possibly conversions to an open procedure will be reduced, although tjhis was not proven by this feasibility study. We have the impression that this navigation system might prove to be advantageous in laparosopic colorectal surgery.
Session: Podium Presentation
Program Number: S042