Endoscopic removal of large colon polyps carries the potential risk of bleeding and perforation complications. Also, giant polyps themselves are more difficult to remove endoscopically. We present a method to reduce the size of polyps by injecting epinephrine prior to polyp removal, which can make the polyp removal easier and reduce the risk of complications. For short-tipped or subtipped giant polyps, endoscopic injection of epinephrine saline at multiple points in the polyp tissue and the tip or peri-tip tissue is performed for at least 5 minutes before polyp collar removal. The change in polyp volume before and after removal was calculated. After the polyps were injected with epinephrine saline, the volume of the polyps was reduced by approximately 72% compared to the pre-injection period. All polyps were easily removed by traps. No bleeding or perforation occurred postoperatively. Reduction of polyp volume assisted by injection of epinephrine saline for endoscopic removal of colonic giant polyps is a safer operation. It is worthwhile to promote this operation because it is simple and easy to master.
Bleeding and perforation are common complications of polyp removal by colonoscopy. The risk of endoscopic polyp removal is higher for large colon polyps (>3.0 cm in diameter). Moreover, endoscopic removal is also quite difficult due to the impact of large polyps on the operative field of view and other aspects. We first performed epinephrine volume reduction (EVR) for giant polyps according to the literature [1] and then removed the polyps, which effectively prevented the risk of surgical bleeding or perforation and reduced the difficulty of endoscopic removal of giant polyps, with better results, as reported below.
The patients were from the Department of Gastroenterology of the First Affiliated Hospital of Guangzhou Medical College from March to May 2008 for endoscopic polyp removal. The ages ranged from 46-65 years old, and all were male patients. All patients signed an informed consent form before surgery and agreed to the procedure.
The polyps we treated were subtibial or short-tibial polyps, and the EVR injection needle used was an Olympus varicose vein injection needle with a tip length of about 4-5 mm outside the cannula. after the polyps were found during endoscopy, 2-4 points were first selected in different directions (anterior and posterior or left and right) of the polyps, and each point was injected with 1:10,000 epinephrine saline Then, 2 points were selected at or near the tip of the polyp, and 1.0 mL of epinephrine saline was injected at each point, and the colonoscopy was continued. On slow retreat the scope is observed to the target polyp site. At this point, the polyp will generally be reduced in size to varying degrees and can be better visualized endoscopically. If necessary, an additional 1.0 mL of epinephrine saline can be injected into the mucosa at or adjacent to the tip. Then, routine endoscopic removal of the high-frequency electrocoagulation capsule is performed. Finally, the incision can be stained and inspected to ensure the integrity of the resection. If the incision is large, a metal titanium clip is placed to close the wound to prevent rebleeding.
For comparison, we took the smallest diameter of the polyp and referred to the calculation of the volume of polyps before and after ERV according to the formula (volume = [4/3]πR3) according to the method of literature [1].
Results The four cases of giant polyps done in our group had a large diameter of about 6.5 cm and a minimum of 3.5 cm, with an average diameter of about 5.4 ± 1.3 cm and an average volume of 302.3 ± 98.3 cm3. After performing EVR for 5 min, the polyp diameter was reduced by an average of 2.87 ± 1.25 cm and an average volume of 84.9 ± 75.9 cm3, and the average volume of polyps was only about 28%. Therefore, the polyps could be better visualized and easier to trap when trapping was performed after EVR of the giant polyps. All polyps were successfully and completely removed endoscopically with ERV without bleeding or perforation. There were 2 cases of subtibial polyps over 6.0 cm in diameter, and the wounds were closed with tongs clips after resection. None of the patients had postoperative abdominal pain and ate normally on the second postoperative day. Pathologically histologically all polyps were tubular-villous adenomas, one of which was a severe atypical hyperplasia, but histopathological examination of the tip showed no abnormality.
Typical case: Patient Wu, 59 years old, male, from Hong Kong. Physical examination colonoscopy revealed a subtibial villous polyp of about 5.0×6.5 cm in size in the sigmoid colon. Histological examination of the polyp biopsy was reported as: tubular – villous adenoma with moderate atypical hyperplasia. The endoscopic polyp was treated with ERV and removed by trap, and the procedure went smoothly without bleeding. The size of the polyp after removal was 3.5×4.5 cm in size. However, as the polyp removal left a wound about 0.5 cm in size on the mucosal surface, the wound was closed with 3 tongs clips. The patient had no bleeding after the surgery and no abdominal pain or other uneventful reactions. The histopathological report of the polyp after removal was: tubular-villous adenoma with moderate atypical hyperplasia and some active glandular hyperplasia.
Discussion Endoscopic removal of colonic polyps by trap is a routine technique. However, there are inherent risks associated with this technique, such as bleeding or perforation. This is especially true for giant polyps. On the one hand, because of the relatively low incidence of giant polyps, there is relatively little training and experience in operating on such polyps, and on the other hand, giant polyps have a relatively abundant blood supply and thicker vessels supporting the polyps, which are also prone to bleeding. Due to the large size of the polyp itself, especially in short-tipped or subtipped polyps, the whole polyp, especially the tip, cannot be effectively visualized, making the removal process somewhat blind; moreover, the cancer rate of giant polyps is also higher, which increases the chance of possible perforation.
For the removal of large polyps, the usual endoscopic techniques include piece meal resection, ligation of the tip with metal tongs or nylon cords, and then removal. However, these operations are quite time-consuming and there is still a greater possibility of bleeding during the excision of polyps. In China, high-frequency electrocoagulation removal with adjuvant epinephrine injection has also been used to perform resection of giant polyps [3], but there is still a greater chance of complications with the use of fractional resection. Therefore, sometimes, a combination of laparoscopic soft and hard removal is adopted for huge polyps. This approach significantly increases the cost of treatment. We have slightly modified the method according to the literature [1] and used epinephrine injection for volume reduction to assist in the removal of colonic giant polyps with better results. No bleeding or perforation occurred after endoscopic removal of giant polyps in all four cases. The rationale for this approach may be that by injecting epinephrine, the polyp tissue or the vasculature at the tip can be constricted, causing ischemia of the polyp tissue resulting in a reduction in tissue volume. The result would be complete endoscopic exposure of the polyp and a more favorable trapping. More importantly, the injection of epinephrine saline into the mucosa at or near the tip not only constricts the blood supply vessels of the giant polyp, reducing the risk of post-circumcision, but also reduces the risk of bowel perforation because the injected epinephrine saline acts as a fluid cushion (fluid cushion). When using EVR for removal of giant polyps, be sure to wait more than 5 min after the injection to ensure the effectiveness of EVR in reducing the size of the polyps.
It is worth drawing attention to the fact that due to the high cancer rate of giant polyps, when doing polyp removal, it is important to do a complete excision and carefully examine the histopathology of the (sub)tip to ensure that no cancer has occurred. In the pathology of this case, although the resected polyp was reported as moderate atypical hyperplasia, the histopathology of the tip and the surrounding area showed normal. However, since pathological histology of the whole tumor is rarely done in China, there is still a possible risk of pathological histological leakage. In order to avoid the possible risk of cancer and early prevention, we suggest the pathology department to actively carry out pathological histological examination of the whole tumor after removal of giant polyps, and at the same time, endoscopists ask patients to perform colonoscopy every three months within six months after endoscopic removal of giant polyps.