1. Hemorrhoids, or hemorrhoids, are one of the most common anal diseases in clinic. 1975, the British Thomson put forward the concept of hemorrhoids in the modern sense [1]: hemorrhoids are pathological hypertrophy of anal pad at the lower end of rectum. Hemorrhoids can be divided into internal hemorrhoids, external hemorrhoids and mixed hemorrhoids.
2. At present, it is considered that internal hemorrhoid is the lesion or displacement of the supporting structure, vascular plexus and arteriovenous anastomosis branch of anal cushion. External hemorrhoids are pathological dilatation or thrombosis of subcutaneous vascular plexus at the distal end of dentate line. Mixed hemorrhoids are a mixture of internal hemorrhoids and external hemorrhoids.
Third, varicose vein theory: venous plexus is the main structure to form anal cushion, and the formation of hemorrhoids is bound to be related to the pathological expansion and thrombosis of venous plexus. Anatomically, the portal vein system and its branch rectal vein have no venous valve; The superior and inferior venous plexus of rectum is thin and shallow; The submucosal tissue of the terminal rectum is slack, which can easily lead to blood stasis and venous dilatation. In addition, because the anorectal tube is located in the lowest part of the abdominal cavity, many factors, such as long-term sedentary, constipation, pregnancy, prostatic hypertrophy, pelvic giant tumor and so on. , can cause rectal venous reflux obstruction. At present, it is controversial.
Fourth, the theory of anal cushion moving down: anal cushion plays the role of sealing anal canal and controlling defecation. Under normal circumstances, the anal pad is loosely attached to the anal canal muscle wall; When defecating, it is pushed down by downward pressure, and then it is retracted into the anal canal by its own contraction. After the elastic retraction ability is weakened, the anal pad is congested and moves down to form hemorrhoids. The mainstream of western medicine supports the theory that anal cushion moves down.
5. Clinically, it is commonly known as PPH (prolapse of hemorrhoids) surgery, which is mainly used to treat patients with ⅲ, ⅳ degree internal hemorrhoids, ⅱ degree internal hemorrhoids and annular hemorrhoids who have failed in non-surgical treatment, and can also be used to treat patients with rectal mucosal prolapse. Its principle is to use a specially designed stapler to annularly remove the rectal mucosa at a distance of 2-4 cm from the dentate line, so that the downward anal pad can be moved up and fixed to achieve the therapeutic purpose. It is characterized by high equipment cost.