Edema of the anal verge (edema of crissum) is one of the common complications after hemorrhoid surgery. Edema of the anal verge is the presence of edema, congestion, bulging and painful swelling of the anal canal and anal verge skin (1). Its edematous tissue is transparent and petechial hemorrhage is visible for a little time, commonly on one side of the anus, even for a week. Once the postoperative anal edge edema occurs, it brings great pain to the patient, prolongs the healing process and affects the healing of the wound. I. Causes 1. Anatomical aspects Hemorrhoid surgery is near the anal dentate line, which is easy to injure the dentate line. Because the submucosal arteries and veins near the dentate line are connected by direct anastomosis and form cavernous veins, in addition the tiny branches of the external and internal hemorrhoidal plexus also traffic with each other. When the hemorrhoid nucleus is congested after treatment such as internal hemorrhoid ligation or injection or after hemorrhoid surgery causing sphincter spasm, through the special structure of the tooth line, it can cause the blood and lymphatic return below the tooth line to be obstructed and form anal edge edema. Ding Xiaohong, Department of Anorectal Medicine, Nantong Hospital of Traditional Chinese Medicine 2. Surgery 2.1 Poor timing of surgery Mostly seen in those with inflammatory external hemorrhoids, embedded hemorrhoids inflammation, and thrombosed external hemorrhoids that are not fully controlled and operated in haste, postoperative inflammation worsens and inflammatory edema forms. Masahiro Takano (2) believes that surgery for acute embedded hemorrhoids may cause the spread of infection or even hemorrhage as a “hypothetical complication” and advocates surgery, but if the infection is already present, the author believes that the inflammation needs to be controlled first. 2.2 Weak concept of asepsis Most of the incisions are infected and cause inflammatory edema due to non-compliance with the principles of aseptic operation. 2.3 Inappropriate injection of drugs When local anesthesia is used, too many drugs are injected or too shallowly accumulated under the skin of the anal verge, resulting in edema of the external venous plexus of hemorrhoids that has to be retained; internal hemorrhoids sclerosis injection of drugs is mistakenly injected below the tooth line. Local anesthesia inadvertently injures the blood vessels in the anus leading to subcutaneous bleeding and easy formation of edema after surgery. 2.4 Incomplete excision Hemorrhoid tissue, especially varicose vein tissue and thrombus stripping is not complete, the residual hemorrhoid tissue within the venous and lymphatic network is destroyed, venous and lymphatic reflux obstruction, causing edema. Wang Yanmei, An Ahh et al. (3) believe that it mostly occurs at the retained skin bridge and in the external hemorrhoid area when the internal hemorrhoid is ligated but the external hemorrhoid is not treated. 2.5 Inappropriate ligation Mixed hemorrhoids are ligated together with a hemostatic clamp on the stump of the external hemorrhoid and part of the base of the internal hemorrhoid before the V-shaped incision is made to the dentate line, and the pain-sensitive area is distributed outside the dentate line, which can cause severe pain and spasm of the sphincter muscle, resulting in obstruction of venous and lymphatic return and edema. (4) According to the theory of anal cushion, the use of external stripping and internal ligation of the dentition line reduces the occurrence of postoperative anal edge edema compared with the traditional external stripping and internal ligation, but the ligation of the pain-sensitive area outside the dentition line should be avoided. 2.6 Poor drainage of the incision Mostly occurs in cases where the incision is too short. Duan et al. (5) believe that the hemorrhoid surgery should be performed by making a radial extension of about 1-3 cm at the distal end of the original incision to reduce the tension incision. Shi RJ et al. (6) believe that the incision is too short due to factors such as relaxation of the anal canal during anesthesia and outward displacement, resulting in the postoperative incision being retracted above the anal skin line and poor drainage of the wound resulting in edema. 2.7 High tension of the incision If too much skin is excised and the width of the skin bridge is small, the skin and subcutaneous tissues of the anus are stretched and compressed during suturing, affecting lymphatic and venous reflux and forming edema. Duan Haitao et al. (7) used “V” shaped, distal extension and parallel 3 kinds of reduction incisions on both sides to prevent anal edge edema and achieved good results; or the skin tissue (skin bridge) was not reset in time after surgery, the dressing was too tightly compressed, and the anal skin and skin bridge could not return to normal position after anesthesia disappeared, resulting in the anal canal skin or skin bridge embedded in the anal opening, and the venous and lymphatic return flow was impaired, resulting in edema. 2.8 Inappropriate surgical operation Unskilled operation, intraoperative clamping of tissues, prolonged operation and aggravation of local injury can cause anal edge edema. 3. Objective causes 3.1 Acute impaction of hemorrhoids, gangrenous hemorrhoids, etc. require emergency surgery, and the potential infection causes postoperative inflammatory edema; for mixed hemorrhoids of large scope, surgery leads to a large anal canal defect, and the pressure at the defect is imbalanced, and the residual skin bridge tissue is squeezed to the defect causing edema. 3.2 Some patients cannot defecate normally due to fear of pain and surgical trauma causing spasm of the sphincter muscle after surgery, and the stagnation of feces compresses the blood vessels, causing obstruction of venous and lymphatic reflux, resulting in edema. Second, prevention After analyzing the causes of postoperative anal edge edema of hemorrhoids, comprehensive Zou Yujuan et al. (8) put forward three-step preventive measures, which are summarized as follows: 1. Prevention-oriented Careful planning of the surgical incision before surgery and comprehensive prevention of the preoperative, intraoperative and postoperative links. Preoperative cleansing enema, so that the patient can defecate after 24 hours after surgery. For embedded hemorrhoids, thrombosed external hemorrhoids, and inflammatory external hemorrhoids, inflammation should be actively controlled before surgery, and surgery should be performed after the inflammation is controlled. During the operation, aseptic operation, design the operation plan according to the condition, execute the operation order, pass the sacral anesthesia, minimize the local anesthesia again after the sacral anesthesia, or the amount of medicine should not be too much when the local anesthesia, move gently and accurately, level the incision, make a radial incision, keep the tension balance between the trauma on both sides of the skin bridge, for the skin bridge movement is large, use suture to fix 1 to 2 stitches, extend the decompression incision appropriately, make the drainage smooth, hemorrhoid nucleus Avoid excessive ligation, otherwise it will cause postoperative edema due to blood and lymphatic circulation disorders, for hemorrhoid subcutaneous thrombosis and varicose veins should be carefully stripped, if the anal stenosis is narrow then part of the internal sphincter should be appropriately cut to reduce the effect of sphincter spasm on local blood circulation, the sclerosing agent should be injected on the tooth line, after injection it can be massaged to make the drug dispersed evenly, after surgery check the bleeding of the wound, fully stop bleeding, the anus should be pressurized bandage for 24 hours. After surgery, control the stool for 24 to 48 hours, eat more vegetables and fruits, and give laxative drugs appropriately to prevent the stool from drying out and squatting for too long, which can cause anal edge edema after earning; however, it is also not possible to use a steep agent, which can cause diarrhea and repeated defecation can also cause anal edge edema. Use antibiotics appropriately to prevent infection after surgery. When changing medication, strictly implement aseptic operation, should first clean the sitz bath, change medication with gentle movements, clean the wound thoroughly, place drainage strips in place, and can massage the perianal area appropriately. 2.Exploration of the operation style Circumcision of mixed hemorrhoids has been eliminated due to many postoperative complications; domestic treatment mostly adopts the method of external incision and internal ligation, but it is still impossible to avoid the occurrence of anal edge edema after the operation. In order to reduce postoperative anal pain and high pressure in the anal canal caused by pressure bandaging, Xu Qiuling et al. (10) used drainage gauze wrapped with small catheters placed in the anal canal to reduce rectal pressure and improve local microcirculation. Based on the special circulation structure of the anal cushion above and below the dentate line, Rong Chun and Rong Xinqi (11) believed that hanging the anal cushion and preoperative anal dilation could help local blood and lymphatic return to the anal canal; Li Jianping and Zhao Ke (12) used in situ flap grafting to preserve the dentate line plus partial internal sphincter dissection to preserve local anatomy and physiological function without blocking blood and lymphatic circulation and prevent postoperative edema of hemorrhoids; based on continuous exploration, China is also absorbing international advanced technology, such as Wen Yuling et al (13) used Takano The Masahiro procedure for multiple mixed hemorrhoids reduces the occurrence of anal edge edema. Once postoperative anal edema appears, it must be actively treated to reduce the patient’s pain and promote the healing of the incision, and the clinical treatment is often both internal and external. 1. Internal treatment The main method is to clear heat, detoxify dampness, benefit qi, moisten bowels, activate blood circulation and relieve pain. Commonly used to cool the blood, Dihuang Tang, Cistanches Rundown Pill and Intestinal Wind San with addition and reduction. Commonly used are Phellodendron Bark, Scutellaria Baicalensis, Atractylodes Macrocephalae, Radix Polygalaeum, Rhizoma Atractylodis Macrocephalae, Herba Cistanches, Dangpi, Radix Paeoniae Alba, Citrus aurantium, Rhizoma Daguerreotis, Radix et Rhizoma Yanhuzo. In modern clinical practice, the use of the drugs (14), (15) and (16) is effective in preventing post-operative edema of hemorrhoids. The effect of these drugs is to reduce vascular permeability, increase venous reflux and improve post-operative edema of hemorrhoids. 2.External treatment Chinese herbal sitz bath Commonly used decoction of 1000ml of water with bitter ginseng, cypress, atractylodes, elm, acacia, cyperus, wupei, lychee grass, park nitro, angelica, red spoon, lactobacillus, xuanhu, etc. first smoked and then washed. Ointment is commonly used to apply Scutellaria baicalensis oil ointment and general anti-swelling powder, which is effective. Inflammatory edema has can be applied externally with oxyfloxacin gel, or Ma Yinglong hemorrhoid cream, compound Yuhong oil cream, Qingliang cream, etc. Medicated wet dressing Inflammatory edema combined with congestive edema can be metronidazole injection (to reduce wound pain and promote healing efficacy (17)) and other rinses and then wet dressing with 50% magnesium sulfate gauze or hypertonic saline gauze, the effect is exact. Anal plugging For smaller anal edge edema that can be held back in the anus by hand, intra-anal plugging of suppositories such as Puji hemorrhoidal suppositories that have the effect of clearing damp heat and reducing swelling is effective. Drug injection Davies J (18) applied local injection of botulinum toxin to reduce the spasm of sphincter muscle, thus preventing and controlling anal edema. Surgical therapy For those with more edema, or those who do not go away for a long time, or those with residual hemorrhoids or subcutaneous thrombi, surgical trimming can be performed again. 3.Other therapies There are also clinical reports of qigong therapy (anal retraction exercise), He-Ne laser, microwave, magic lamp, infrared ray, etc.