Because of the advantages such as real-time orientation, easy operation, no pain and so on, intraoperative colonoscopy in laparoscopic colectomy is regarded as an efficient lesion positioning approach for selected patients with large or broad-based polyps [9, 10]. As we know, the accuracy of lesion location is very important, which directly determines the accuracy of colonic resection margin, especially for patients with benign lesions who intend to undergo local bowel segmental resection. By precise colonoscopic localization of the lesions, long segment colectomy usually could be avoided. Generally speaking, slight deviations of colonic resection margin can be accepted. Large deviations like this case are relatively fewer.
In this case, we took the bright spot of colonoscopy as the center of the lesion under laparoscopy. And the bilateral surgical margins were 4cm away from the center. Therefore, we thought that the lesion should be in the specimen. Then, we anastomosed the colonic stumps firstly and removed the specimen from the abdominal cavity secondly. However, there was no lesion in the specimen. This situation was frustrating. The possible causes were as follows: 1. The distance between the endoscopic light source and the reflective bowel wall can be long or short, which is uncertain. It mainly depends on the angle of the endoscopic light. 2. Pedicle polyps have certain mobility. Therefore, there is a certain deviation if operators focus on the polyp itself rather than the polyp pedicle. In other words, polyp-pedicle localization is more accurate than polyp-body localization.
After analyzing the different irradiation angles of colonoscopy light on polyps, we believe that there are three situations of maximum localization errors as showed in Fig. 2A. These polyps are situated in either direct colonic segments or tortuous colonic segments. The irradiation angle of colonoscopy light on the polyp head and parallel to the colon is responsible for these localization errors. However, these are the most common situations of colonoscopy, and so is gastroscopy actually. In other words, we need to adjust the angle of the endoscopic light source so that the light scattering is the least, and the localization is more accurate. And necessary verification methods should be carried out to ensure accurate localization.
In order to avoid the recurrence of similar incidents, we try to learn from this mistake. There are some suggestions given to peers for ensuring the accuracy of endoscopy localization in laparoscopic segmental colectomy: 1. The direction of colonoscopy light should be toward the root of polyp. Operators do a small push action using endoscopy top, and look for the undulating light spot outside the colon with laparoscope. 2. A small push action is performed with a laparoscopic forcep at this light spot outside the colon. Operators observe whether the undulating point is the root of polyp with colonoscopy. If the internal and external localizations are consistent, make a mark such as metal clips outside the colon. 3. Before colonic anastomosis, the specimen should be taken out immediately after being cut off for localization check(Fig. 2B). These three-step measures provide three-tier insurance. Their advantages include simplicity, practicality and reliable localization. These three-step measures deserve to be popularized not only in colonoscopy assisted operations, but also in gastroscope assisted operations.