Last time we talked about the surgical treatment of ulcerative colitis (UC), this time we talk about the surgical treatment of another inflammatory bowel disease, Crohn’s disease (CD). Unlike ulcerative colitis, Crohn’s disease cannot be cured by surgery, but it would be a mistake to underestimate the important role of surgery in the comprehensive treatment of Crohn’s! I. Introduction to Crohn’s disease Crohn’s disease, once called segmental enteritis, is a transmural inflammation occurring in the GI tract, most commonly in the ileocecal region, but can occur anywhere in the GI tract. The common manifestations of Crohn’s disease are abdominal pain and diarrhea, which are distinguished from ulcerative colitis by left-sided abdominal pain common in ulcerative colitis and right lower abdominal pain common in Crohn’s disease, and mucopurulent stools common in ulcerative colitis and pasty stools common in Crohn’s disease. Intestinal fistulas and perianal lesions are also common manifestations of Crohn’s disease. Intestinal fistulas are penetrating lesions of the intestine. If they penetrate the body surface, they are called external fistulas; if they penetrate the adjacent intestine, they are called internal fistulas; if they penetrate the abdominal cavity or the retroperitoneum, they form abscesses; others are small intestine bladder fistulas, rectovaginal fistulas, etc. The most common perianal lesions are anal fistulas and perianal abscesses. Crohn’s disease may also present with extraintestinal manifestations such as iritis, erythema nodosum, gangrenous pyoderma, and oral aphthous ulcers. The diagnosis of Crohn’s disease relies on gastrointestinal endoscopy, gastrointestinal imaging, abdominal CT, and pelvic MRI. The internal medications are similar and different compared to ulcerative colitis: (a) Aminosalicylates: still the basic medication, but less effective for upper gastrointestinal and small intestinal lesions. Only ethylcellulose semipermeable membrane-controlled release mesalachin tablets have some effect on the distal jejunum and ileum. (II) Glucocorticoids: In addition to various commonly used systemic-acting hormones, there are budesonide tablets acting locally, which have the effect of inducing and maintaining remission for lesions limited to the ileum and ileocecal region. (iii) Immunosuppressants: They are more effective in the treatment of lesions in the upper gastrointestinal tract and small intestine. (iv) Biologics (infliximab): used as a remedy when conventional treatment is ineffective in “step-up” therapy and first used in “step-down” therapy to achieve a high remission rate and reduce complications and surgery. The timing of surgery for Crohn’s disease Crohn’s disease cannot be cured by surgery. The indications for surgery are mainly acute and chronic complications, such as acute perforation, acute hemorrhage, intestinal stricture, intestinal obstruction, intestinal fistula, etc.; surgery should also be considered when medical treatment is ineffective, or when hormone dependence and severe side effects occur. The timing of surgery for Crohn’s disease has a great impact on the outcome and safety of surgery. There are several principles for determining the timing of surgery: (1) surgery in remission is safer than surgery during the active phase; (2) inappropriate prolongation of hormone and infliximab use increases the risk of emergency surgery; and (3) patients with combined malnutrition and abdominal infection are at high risk for surgery. ”Surgery in remission is safer than surgery in active phase”, which applies to both Crohn’s disease and ulcerative colitis, but in practice physicians and patients often have a poor or biased understanding of this statement. For patients with non-emergency complications, such as incomplete bowel obstruction, abdominal infection, etc., surgeons will allow patients to be treated conservatively first and then operate after remission and systemic improvement. However, some patients are reluctant to have surgery after remission, thinking that surgery will not cure Crohn’s disease anyway, and that I’m doing fine after remission, and that my condition may get worse after surgery. This idea is not correct, the intestinal canal where obstruction and intestinal fistula occur is often the intestinal canal that has been fibrotic after recurrent attacks, and even if the disease is in remission, the fibrosis cannot be reversed. Third, the fibrotic intestine is an important origin of future disease recurrence, a source of future intestinal fistula, a high-risk area for intestinal stricture, and a time bomb for perforation or bleeding. Therefore, for patients with Crohn’s disease who already have irreversible lesions such as intestinal fibrosis, remission does not mean that surgery is not necessary, but rather that they have encountered a rare opportunity for surgery and should actively communicate with their surgeon to determine the timing and plan for surgery. ”Surgery in remission is safer than surgery in active disease,” but it would be a misunderstanding to exclude emergency surgery in critically ill patients because of this. Some patients with Crohn’s disease may suddenly worsen during the course of the disease and develop severe active Crohn’s disease. Such patients often have a combination of severe systemic symptoms, such as hyperthermia, sepsis, and so on. Hormones are usually given immediately to induce remission in such cases, but they are not effective in all cases, and they can have an impact on the risk of surgery. Studies have shown that preoperative hormone use for more than 1 week in emergency patients significantly increases the rate of surgical complications. Therefore, when hormone use is ineffective for 3 days, infliximab should be added promptly, and active surgery is required if observation is still ineffective for 3 days. If the patient’s condition is already particularly critical or continues to worsen during the hormone treatment phase, it is expected that infliximab treatment is not promising when surgery should be performed directly instead of wasting time on unnecessary medical treatment. The “top of the line” combination of hormones and infliximab is now advocated for patients with severe active Crohn’s disease, also with the aim of shortening the observation period for patients who have failed to respond to treatment and taking the necessary surgical treatment in a timely manner. Due to gastrointestinal dysfunction, systemic inflammation and drug side effects, patients with Crohn’s disease often have reduced or increased intake of protein, energy, vitamins and trace elements, resulting in malnutrition such as wasting, anemia and hypoproteinemia. More than 85% of Crohn’s disease patients requiring surgery have malnutrition, a much larger percentage than in ulcerative colitis. Patients with combined malnutrition undergoing surgery tend to be more prone to incisional infections, incisional hernias, anastomotic fistulas, abdominal infections, and pulmonary infections. According to European studies, preoperative nutritional support for about 2 weeks can significantly improve clinical outcomes in patients at nutritional risk, but nutritional support in Crohn’s disease can be anything but straightforward. Since patients have impaired gastrointestinal function and poor tolerance to the speed and dosage of nutrition, they often need to be placed nasogastric tubes and nasal-intestinal tubes for homogeneous tube feeding, and comprehensive management is required in the selection and use of preparations, which not only increases the workload of doctors and nurses, but also places demands on patient compliance. Only with mutual trust, full communication and harmonious cooperation between doctors and patients can the best treatment effect be achieved. Patients with Crohn’s disease are prone to abdominal abscesses, which are a risk factor for increased surgical complications. Therefore, for patients with abdominal abscesses, abscesses should be drained by puncture or surgery first, and definitive surgery such as bowel resection should be performed after the infection is controlled or disappears, rather than dealing with the abscess and diseased bowel at the same time. Abscess drainage should be performed while flushing, which can adequately reduce colonization and necrotic tissue and prevent thick pus from blocking the drainage tube. In some patients, drainage of abscesses allows healing of the intestinal canal lesions, thus avoiding surgery, and even if bowel resection is still required, the risk of surgery is significantly reduced. Therefore, to summarize the timing of surgery for Crohn’s disease, hormonal therapy should not be observed for more than 1 week for severely active lesions; patients with non-emergency conditions should be scheduled for surgery in remission if possible, and interventions should be given before surgery if malnutrition and abdominal abscesses are present. Third, surgical methods Different from ulcerative colitis, Crohn’s disease cannot be cured by surgery, which contains two levels of meaning: first, even if all the diseased intestinal tubes are removed, they may still recur in the remaining gastrointestinal tract; second, Crohn’s disease recurrence may require another or multiple surgeries to remove the intestinal tubes, and may even have too many intestinal tubes removed to develop short bowel syndrome, etc. Therefore, the scope of surgery for Crohn’s disease should be limited to the “criminal” intestinal tube that causes complications, rather than blindly expanding the scope in an attempt to “clean up” the lesion. The common surgical procedure for Crohn’s disease is bowel resection anastomosis. It is important to note that only bowel tubes without active inflammation can be anastomosed, while if the bowel tube is significantly inflamed and edematous, only an enterostomy or a protective enterostomy can be made proximal to the anastomosis. In order to reduce recurrence, there are a number of considerations for resection anastomosis in Crohn’s disease: First, as shown below, a traditional lateral anastomosis in the retrograde peristaltic direction requires a “U-turn” when food is transferred to the anastomosis, whereas a lateral anastomosis in the prograde peristaltic direction requires only a “lane change” when food is transferred to the anastomosis. The lateral anastomosis in the cis-peristaltic direction only requires a “lane change”, which is certainly more laborious than a lane change. In patients with intestinal tumors and trauma, the difference between the two types of anastomosis is not significant because the intestinal dynamics are basically normal; however, in Crohn’s disease, because the intestinal dynamics are impaired, the use of lateral anastomosis in the cis-peristaltic direction can reduce the burden on the intestine, so that the retention of food residues and bacteria in the anastomosis is reduced and the chance of recurrence is reduced. Secondly, the typical manifestation of Crohn’s disease is a cleft-like ulcer, and all cleft-like ulcers are in the mesenteric side of the intestinal wall, so the anastomosis should be performed with an anastomosis to the mesenteric side of the intestinal wall. Thirdly, traditional intestinal anastomosis uses silk thread, the material of which is silk protein, which is prone to tissue rejection and even the formation of infected small abscesses at the anastomosis; therefore, we advocate the use of anastomosis and absorbable thread, the material of which is metal and polyester, which can significantly reduce tissue rejection and thus reduce recurrence. In addition to intestinal resection anastomosis, there are some offenders whose intestinal tubes cannot be resected due to adhesions and other reasons, which may require intestinal short-circuiting, stenoplasty, stoma, etc. The above principles should also be followed. Laparoscopy is a trend in the development of gastrointestinal surgery, and this technology has gone from initial questioning, to gradual acceptance, to promotion, and now to full development. A doctor who does not understand laparoscopy is unlikely to gain a foothold in the future of gastrointestinal surgery. For the application of laparoscopy in inflammatory bowel disease, it was thought to have the disadvantage of a long learning curve, but in our department, because the doctors have already mastered the more demanding laparoscopic techniques through other surgeries, they are comfortable applying it to inflammatory bowel disease. The use of laparoscopy for Crohn’s disease not only implies technical advancement, but also brings tangible benefits to patients. It has been shown that laparoscopic surgery can speed recovery from Crohn’s disease, reduce incisional and abdominal infections, and shorten the length of hospital stay. However, because Crohn’s disease is prone to abdominal infections and repeated surgery may aggravate abdominal adhesions, it requires not only preoperative screening of appropriate cases but also strong resilience on the part of the surgeon in charge.