There is a general consensus that for all endoscopic manipulations of tissue including biopsies, minimal requirements for blood coagulation (quick test result of more than 65%, thrombocytes more than 100,000) have to be proved.

Medication with 100 mg acetic acid is no longer regarded as contraindication for endoscopic manipulations. For details, there is a special chapter at the end of this book. Also see the actual recommendations on the homepages of the scientific organizations.

Pollution of the examination site by food and feces compromises the diagnostic value of the endoscopy. Furthermore, this may cause risks for aspiration and perforation. The examiner has to decide whether to abort the exam or to continue with cleansing by flushing and suction.

For endoscopic resections in particular, a clear action field is mandatory.

Mostly in the left colon, adenomas typically form a pedunculated tumor with a less or more slim polyp. This observation is the background for the term «polyp,» which is not a proper medical description. At the start of endoluminal diagnosis with barium enemas and later with the first fiber endoscopes, this type of adenoma was the first which could be detected. Later, with the progress in diagnostic sensitivity, flat adenomas have also been discovered, but the unfortunate term «polyp» was retained. Nowadays, we know that colorectal adenomas have very different shapes ranging from pedunculated, sessile, and flat adenomas to those with depressions or ulceration (◘ Figs. 1.2, 1.3, and 1.4).

The most common and relevant tumors are adenoid tumors.

Experienced examiners can rate the entity of the lesion by subtle inspection of its surface. If in doubt, a sample for histopathological exam is mandatory. Furthermore, an endosonography can clarify whether the lesion infiltrates the submucosal layer or deeper parts of the wall of the GI tract. In the majority of cases, and especially if the polyp has a visible polyp, an endosonography is not required.

A polypectomy is indicated for:

Other polyps such as lipomas require removal only if they compromise passage, are ulcerated, or are bleeding.

Under certain circumstances (patient’s wish, urgent indication for anticoagulation, and low evidence for the existence of polyps), an examination without polypectomy is acceptable. Also, for very large lesions with risky removal, the resection should not be forced. For these cases, additional patient information and different settings for the removal including referral to specialized centers are recommended.

In the colon, the resection should start at the highest (cecal) position and then in the direction of the anus. Because the resection site is a location of reduced resistance, unnecessary endoscopic passages should be avoided.

In the upper GI tract, the operation should be carried out from the aboral to the oral end.

Exceptions from this recommendation are very small or hidden polyps which can be removed by biopsy forceps immediately or can be marked within the first endoscopic passage.

If the exam reveals findings which require resectional surgery, the indication to remove further lesions depends on the following operation. If a right-sided hemicolectomy is planned due to a cecal carcinoma in the left hemicolon, every polyp should be removed to clarify its malignancy status. For small lesions, an endoscopic tattooing is recommended to improve intraoperative recognition of the tumor. Avoiding intraoperative colonoscopy has some logistic advantages.

From the endoluminal aspect, it remains unclear in which part the colonic wall is covered by meso and in which it is not. Therefore, the tattooing should be injected in three corresponding parts of the colonic wall. Beginning with submucosal deposits of saline solution, these can afterward be marked with ink (◘ Fig. 1.15) (Yeung et al. 2009; Bergeron et al. 2014; Haji et al. 2014).

Before starting the polypectomy proper, prophylactic hemostasis should be considered.

Therefore, ligation loops (as a single-use product or with reusable applicator) can be used. The placement of the ligation loop should ensure a sufficient distance to the margin of the lesion. A prophylactic injection of saline or diluted noradrenaline solution (1:10,000) to the basis of the polyp is cheaper. It has to be considered that the flattening of the polyp caused by injection may handicap the placement of the snare. Even prophylactic clipping could make further resection difficult.

In the author’s experience, bleeding prophylaxis may be dispensed with, especially in pedunculated polyps. Priority should be given to a complete resection; post-resectional hemostasis is successful in nearly all cases.

To place the polypectomy snare, an excellent overview is mandatory. Remaining feces should be removed by flushing completely. The scope position should be stabilized. Balancing insufflation and suction and if necessary Buscopan i.v. administration can help to reach good visibility of the resection side.

In large polyps, the lesion should be passed. After complete opening of the snare, the polyp should be caught by withdrawing the scope with the open snare.

Closing the snare according to the order of the examiner is a very responsible task for the assisting person. If the snare is not closed strongly enough, the lesion can slip out. If it is closed too strongly, there is a risk of «cold snaring,» i.e., a cut without electrocautery which may cause bleeding in large lesions. Of course, experience and clear communication within the team support a successful procedure.

Furthermore, there are other risks associated with failed placements of the snare. Unnoticed grasping of healthy folds beyond the polyp can cause damage. If the snare is placed very close to the base, the risk of unintended resection of deeper layers of the GI tract wall as the muscular layer increases.

If in doubt, the snare should be reopened and the situation should be reviewed. Many textbooks recommend avoiding contact with the contralateral mucosa. In large polyps, this can be very cumbersome or impossible. Due to the improvements in modern HF generators, the risks of creeping electroenergy and consequent collateral damage have been significantly reduced (◘ Fig. 1.17).

The cutting of the polyp base is carried out by moderate traction on the handle of the polypectomy snare. Modern HF generators provide special settings for polypectomy which consist of a defined alternating application of cutting energy and hemostasis. The correct setting and the use of the yellow pedal for cutting are important (this color code is a manufacturer-independent international standard).

The previously practiced so-called stutter cut (repeated short-time activation of the pedal) is not recommended anymore because this compromises the «endo cut» or other cutting modes. They contain a first-cut phase and then alternating cutting and coagulation modes.

This guarantees an optimal balance for effective prevention of bleeding and a small zone of electrocoagulation which allows an adequate histopathological exam.

Possible bleedings and visible lesions of the muscular layer (see also ► Sect. 3) can be managed easily with endoscopic clips. Small and diffuse bleedings can be treated by local injection or thermal therapy with argon plasma coagulation.

To harvest the polyp, different methods can be used. Depending on its consistency, polyps up to 8 mm in size can be sucked through the instrumentation channel. For this purpose, polyp traps can be mounted between the endoscope and the suction tube. This is very helpful, in particular if there are several polyps in the right-side colon (see ◘ Fig. 1.8).

If the polyps are too big for the transendoscopic suction, they can be grasped with the snare itself. This is sometimes difficult and the polyp can be divided by strong traction. Many manufacturers offer special polyp graspers with three or four arms or endoscopic nets. The latter are very useful, in particular for the harvesting of several polyps or fragments. They can be reopened to catch further polyps without loss of the previously caught polyps, due to their adherence to the net.

Another advantage of these devices is the ability to watch the mucosa while withdrawing the scope together with the net. Of course, large polyps can be sucked directly to the scope and transported by that. Because this compromises the endoscopic view, this method is recommended exclusively for the sigmoid colon and rectum.

Resected polyps sometimes move away from the resection site very quickly in both directions. From time to time, it can be very frustrating to search for them. The decision to continue polyp search or to sieve the stool may be made on the basis of an individual look at the relevance.

As well as the polypectomy, EMR has a double character as a diagnostic and as a therapeutic measure. The complete resection can be regarded as a «total biopsy» and doesn’t require a previous biopsy.

But nevertheless, to start a successful and complete resection, all requirements should be given. This includes patient conditions (informed consent, coagulation, adequate follow-up), the lesion (infiltration depth, size), and the related logistics (instrumental and personal equipment, time slot, experience). An intended incomplete resection is not recommended because this compromises later completion.

Of course, the infiltration depth can be detected by endoscopic ultrasound. This is well established for the rectum, esophagus, stomach, and duodenum; for the colon and small bowel, it is not. Because the exact measurement of the tumor staging, in particular the depth of infiltration to the submucosal layer, is not reliable, some experienced endoscopists abstain from endosonography. They estimate the tumor stage on the basis of subtle endoscopic inspection (Bergeron et al. 2014; Haji et al. 2014).

Nonetheless, the author recommends routine use of endosonography prior to resection in the upper GI and in the rectum because of the possible detection of additional findings such as lymph node enlargement, its risk-free performance, and its training effect.