Acute appendicitis is a common surgical condition and the most common acute abdominal condition. Etiology 1. Obstruction of the appendiceal lumen is the most common cause of acute appendicitis. Fecal stones or stones in the appendiceal lumen are the common causes of obstruction, while foreign bodies, inflammatory strictures, food residues, roundworms, and tumors are less common causes. After the appendiceal lumen is blocked, the appendix still continues to secrete mucus, the pressure in the lumen rises, and blood flow becomes impaired, which makes the appendiceal inflammation intensify. 2.Bacteria invasion The appendix is connected with the colon, and when obstruction occurs, the bacteria that remain in the distal dead space can easily multiply. Bacteria cross the ulcer and enter the appendiceal muscular layer. The interstitial pressure of the appendiceal wall increases, impeding arterial blood flow and causing appendiceal ischemia, which eventually causes infarction and gangrene. Clinical symptoms 1. Metastatic right lower abdominal pain: The typical abdominal pain episode starts in the upper abdomen, gradually moves to the umbilicus, and finally metastasizes and is confined to the right lower abdomen. The length of the course of metastatic right lower abdominal pain depends on the degree of lesion development and the location of the appendix; it cannot be less than about 2 hours if it is fast, and can be 1 day or longer if it is slow, but if the abdominal pain metastasizes in a few minutes, appendicitis is unlikely. About 70% to 80% of patients have this typical feature of metastatic abdominal pain; there are also some cases in which the onset of the disease starts with right lower abdominal pain. The abdominal pain is usually persistent and may be mild at the beginning of the disease, which is easily ignored by the patient. 2, gastrointestinal symptoms: early onset may have anorexia, which may also be the first symptom. Nausea and vomiting may also occur, but to a lesser extent. Vomiting usually occurs once within a few hours after the onset of abdominal pain and is not frequent. Diarrhea may occur in some cases. 3. Systemic symptoms: early weakness. Toxic symptoms, panic, fever and elevated body temperature up to about 38℃ when inflammation is heavy. In case of appendiceal perforation, the body temperature is higher, reaching 39℃ or 40℃. However, the temperature increase does not occur before the abdominal pain. Treatment In principle, once acute appendicitis is diagnosed, the appendix should be removed surgically as soon as possible. Early surgery is safe, simple and can reduce the occurrence of recent or long-term complications. If the appendix progresses to septic gangrene or perforation, surgery is difficult and postoperative complications increase significantly. Even if nonsurgical treatment allows the acute inflammation to subside, recurrence will occur in approximately 3/4 of patients later. Non-operative treatment is only indicated in cases of simple appendicitis that do not agree to surgery, before or after undergoing surgical treatment, or when the diagnosis of acute appendicitis has not yet been established, and when there are contraindications to surgery such as the onset of the disease for more than 72 hours or the formation of an inflammatory mass. The main measures include the selection of effective antibiotics and rehydration therapy. Appendectomy can be accomplished either by conventional open or laparoscopic. Compared to both, laparoscopic treatment of patients has the advantages of less postoperative incisional complications, faster recovery, earlier return to work, and lower incidence of adhesive bowel obstruction. In simple appendicitis, no drainage is usually placed after surgical resection. Drainage should be placed in patients with localized abscess cavity and heavy inflammation. Complications of acute appendicitis 1. abdominal abscess: a consequence of untreated appendicitis. Abscesses can also be formed in other parts of the abdominal cavity, commonly in the pelvis, subdiaphragm or intestinal space. The recurrence rate of appendiceal abscess is high after its cure by non-surgical treatment, so the appendix should be removed by elective surgery about 3 months after cure, which is more effective than emergency surgery. 2. Formation of internal and external fistula: If the abscess around the appendix is not drained in time, in a few cases, the abscess can penetrate into the small intestine or large intestine, and also into the bladder, vagina or abdominal wall, forming various internal or external fistulas, at which time the pus can be discharged through the fistula. Complications of appendectomy 1, bleeding: the main cause is due to inflammation heavy appendiceal vascular ligation off, etc. 2.Incisional infection: It is the most common postoperative complication. It mostly occurs in septic, gangrenous appendicitis and combined with perforation. Treatment principle: the pus can be extracted by trial penetration first, or the sutures can be removed at the fluctuation to drain the pus and open drainage; if the location is deep, it cannot be satisfied with subcutaneous drainage only; at the same time of drainage, foreign bodies such as silk threads in the wound should be cut out and the medicine should be changed regularly. The widespread development of laparoscopic appendectomy can significantly reduce the occurrence of incisional infection. 3.Adhesive intestinal obstruction: It is a more common long-term complication after appendectomy. It occurs mostly in appendiceal perforation complicated by peritonitis, and is related to various reasons such as heavy local inflammation, surgical injury and postoperative bed rest. Early surgery, postoperative left lateral position, and early bed release can prevent this complication appropriately. The obstruction can be relieved by active anti-infective treatment and systemic supportive therapy. If it is not relieved and develops into complete intestinal obstruction, surgery is required. 4.Fecal fistula: It is rare. It mostly occurs in gangrenous appendicitis, appendiceal root perforation or severe cecum lesions. The fecal discharge is often discharged from the incision within a few days after surgery, and the rest is similar to the clinical manifestations of periappendiceal abscess. If there is no obstruction in the distal intestine, it can mostly close by itself with non-surgical treatment such as drug exchange. If it does not close after 2 to 3 months, surgery is required.