5 ways to easily fix colon polyps

It is only for medical professionals to read and refer to different types of colon polyps, the choice of endoscopic resection.

Colorectal cancer is one of the main cancers that threaten the lives and health of our residents, causing a serious social burden.

According to the latest data released by the National Cancer Center, in 2020, there were 555,500 new cases of colorectal cancer in China, accounting for 12.
2% of all malignant tumors; 286,100 deaths caused by colorectal cancer, accounting for 9.
5% of all malignant tumor deaths [1].

About 95% of colorectal cancer develops from polyps, which can be divided into adenomatous polyps and non-adenomatous polyps according to histological characteristics.
The former includes villous, tubular and mixed polyps, and the latter includes juveniles.
Polyps, inflammatory, proliferative and hamartomatous polyps.
The malignant transformation of polyps mostly follows the "adenomas-carcinoma" sequence, but studies have reported that inflammatory polyps and hyperplastic polyps can also become cancerous, progressing from precancerous lesions to cancer It usually takes 5 to 10 years [2-3].

Therefore, the principles of early detection and early resection should be followed for colon polyps.

The resection of polyps is currently mostly treated by endoscopic resection.
The main surgical methods include biopsy forceps polypectomy, snare polypectomy, endoscopic mucosal resection (EMR), and endoscopic submucosal resection ( endoscopic submucosal dissection, ESD) etc.

There are many types of colonic polyps for endoscopic polypectomy, and the choice of surgical method depends on the specific shape and size of the polyp; the polyp shape is simply divided into the uplift type and the flat type, and the specific shapes are as follows: 1.
Protruding lesions clearly bulge in the intestinal cavity, and the diameter of the base is significantly smaller than the maximum diameter of the lesion (pedicle or sub-pedicle); or the lesion is hemispherical, and the diameter of the base is significantly larger than the diameter of the head of the lesion.

①Type Ⅰp, namely the pedicle type, the base of the lesion has an obvious pedicle connected to the intestinal wall; ②Type Ⅰsp, namely the sub-pedicle type, the base of the lesion has an pedicle connected to the intestinal wall; ③Type Ⅰs, the lesion is obviously raised on the mucosal surface, but The base of the lesion has no obvious pedicle structure, and the diameter of the base is obviously larger than the maximum diameter of the head of the lesion.

2.
Flat type lesions with low height or flat raised type are collectively referred to as flat type.

①Type Ⅱa, that is, the diameter of the lesion is less than 10 mm, the lesion is flat or slightly taller than the surrounding mucosa.

②Type Ⅱb, that is, there is almost no height difference between the lesion and the surrounding mucosa; ③Type Ⅱa+dep, that is, the type Ⅱa lesion has shallow depressions; ④Non-granular LST: The tumor group with a diameter greater than 10 mm and mainly developed laterally Collectively referred to as laterally spreading tumor (LST), the ones without grains and nodules on the surface are called non-granular LST, which can be further divided into flat and protruding and pseudo-recessed types; ⑤Granular LST: the previous The particle cluster type lesions, nodular cluster-like lesions, IIa cluster type, stolon shaped tumors, etc.
, once called, can be divided into uniform particle type and mixed nodule type.

Figure 1 Figure 2 (This picture comes from the Internet) Different types of polyps, how to choose endoscopic resection? Considering the shape and size of polyps, the "Guidelines for Screening and Early Diagnosis and Treatment of Colorectal Cancer in China (2020, Beijing)" recommends: (1) Snare resection is recommended for small lesions with a diameter less than 5mm; biopsy forceps can still be considered Clamping surgery; (2) For small lesions with a diameter of 6 to 9 mm, snare resection, especially cold snare resection is recommended; in addition, endoscopic mucosal resection can be considered for treatment of difficult-to-resectable lesions; (3) ) For uplifted lesions (type Ip, Isp, and Is) with a diameter> 10mm, it is recommended to select an appropriate snare resection based on the characteristics of the pedicle.
For flat types that can be completely resected in one go (type IIa, type IIb) Type, type IIc) and some type Is lesions, EMR treatment is recommended.

In principle, the maximum diameter of lesions that can be resected in one piece by EMR is less than or equal to 20mm; (4) For lesions with a maximum diameter greater than 20mm that are difficult to use EMR for complete resection, lesions with negative lift signs, and residual EMR greater than 10mm or after treatment Recurrence of lesions that are difficult to treat with EMR is recommended to use ESD for treatment.

(5) When ESD is indeed difficult to carry out due to technical difficulties, the use of segmented EMR technology (endoscopic piecemeal mucosal resection, EPMR) can be considered for lesions with the largest diameter> 20mm [4].

At the same time, there are also reports in the literature that for flat polyps of 6 to 20 mm, modified EMR (modified-endoscopic piece meal mucosal resection) can be used [5].

What is the difference between the above surgical methods, the following is a brief introduction: (1) Biopsy forceps polypectomy: including cold biopsy forceps polypectomy and hot biopsy forceps polypectomy, biopsy forceps are usually used to remove colorectal polyps below 5mm.

A recent study of biopsy forceps polypectomy for 3-5mm colorectal polyps by scholars has shown that as the size of polyps increases, the clearance rate of one-clamp occlusion will decrease, and the rates of polypectomy with one-bite biopsy forceps for 3mm, 4mm and 5mm polyps are respectively It is 92%, 60% and 31% [6].

Hot forceps biopsy is another method to remove tiny polyps (≤5mm).

Although hot biopsy forceps are an option for polypectomy, it is easy to cause unnecessary injury area to increase, and easy to form penetrating injuries, so it is usually not recommended.

Figure 3.
Polypectomy with cold biopsy forceps (2) Snare polypectomy: Snare is divided into cold snare and hot snare.

① The basic principle of thermal snare polypectomy is that if enough current is passed through, the heat generated will rupture the cells and cause the tissue to be cut.

For small polypectomy, thermal snares are not recommended because of the risk of thermal adverse events.

It is recommended that the thermal snare be used for 10-19mm pedunculated polyps.
Because the stem of pedunculated polyps has penetrating blood vessels, some form of pre-prevention of blood is required.

The cauterization caused by thermal snare polypectomy is a means to prevent immediate bleeding.

②The cold snare has the ability to remove the entire polyp, avoiding fragmentary removal, and can be used for larger polyps found in the same process.

Its advantage is that it can prevent the damage to the submucosal vascular tissue caused by electrocautery, and there are fewer restrictions on the patient's postoperative activities or diet.

Because electrocautery is not used during cold snare polypectomy, the incidence of postoperative bleeding and perforation is low [7].

Figure 4.
Snare polypectomy (3) EMR: commonly used to remove sessile polyps, by injecting buffer into the submucosal space to separate the epithelium from the underlying tissue and separate the lesion.

Including en bloc resection and fractional resection.
At present, submucosal injection resection is the most commonly used EMR resection method.
Other EMR resection methods include transparent cap assisted EMR, water injection/underwater EMR, etc.
EMR is in the realization of colorectal polyps The complete endoscopic resection is significantly better than the cold snare, but it requires submucosal injection and electrocautery, so complications such as delayed bleeding, post-polypectomy syndrome and perforation are inevitable.

Figure 5.
Endoscopic mucosal resection (4) ESD: Compared with EMR, ESD can minimize the residual and recurrence of tumors.

ESD usually applies> 20mm, non-granular lateral developmental lesions.

ESD is a technique with a low recurrence rate and better pathological specimens compared to traditional sliced ​​mucosal resection.

The disadvantage of ESD is the high perforation rate and the time-consuming process.

A number of studies have shown that the ESD perforation rate is about 5%.

A large number of studies have reported the clinical results of ESD, the good curative effect of en bloc resection, and the long-term low recurrence rate of large superficial colorectal tumors.

Figure 6.
Endoscopic submucosal dissection (5) Modified EMR (M-EMR): M-EMR uses partial ESD technology.
After fully injecting the submucosa around the polyp, push the tip of the snare 3mm outside the periphery of the polyp After a little out of the sheath, cut the normal mucosal tissue with the tip.
A round-shaped groove is formed around the lesion.
The metal ring of the snare is slightly shaken and placed in the groove.
Slowly tightened and then coagulated.

Advantages of M-EMR: ①The edge is accurate and can be excised according to the pre-set edge; ②The resection is complete without residual lesions, reducing the recurrence rate, especially for lesions that require complete resection of microvascular and gland changes that are indicated by magnifying endoscopy; ③No need Increase the treatment accessories, only use the tip of the snare to cut the mucosa, which is convenient to operate and does not increase the patient's medical expenses.

Disadvantages of M-EMR: Part of the ESD technology is adopted, which has higher technical requirements for doctors than traditional EMR in operation.
Therefore, doctors are required to have more mature technology, which is less popular.

Endoscopic resection has become the main surgical method for the treatment of colon polyps.
It has the advantages of simple operation, safety, and less trauma, and is currently widely promoted in clinical practice; understand the advantages and risks of each surgical method, and choose the appropriate surgical method , It can reduce the risks during and after the operation and benefit the patients.

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