Crohn’s disease, also known as segmental enteritis or Crohn’s disease, originally referred to an inflammatory lesion predominantly of the ileum that began in the mucosa and invaded the entire intestinal wall. Nowadays, it is found that this inflammatory lesion can occur in the entire GI tract. Surgical complications of Crohn’s disease include intestinal obstruction, intestinal perforation, gastrointestinal bleeding, intestinal fistulas, and abdominal infections. These complications often alternate, leading to malnutrition and organ dysfunction in patients and, in severe cases, death.
The principles of medical treatment are mainly to induce and maintain remission of Crohn’s disease, but cannot prevent the development of complications. Surgeons should be familiar with the development of Crohn’s surgical complications and intervene at the right time to reduce the incidence of serious complications and mortality.
I. Types of surgical complications and principles of surgical treatment
1.Intestinal obstruction
The main cause of intestinal obstruction is the recurrence of inflammatory lesions and scarring stenosis combined with ulcer repair, and inflammatory edema of the mucosa can aggravate the stenosis and obstruction. Stenosis can occur in the terminal ileum and also in the ileocolonic anastomosis.
For Crohn’s disease combined with intestinal obstruction, non-surgical treatment can be tried first. The first step of non-surgical treatment is fasting, total parenteral nutrition support, gastrointestinal decompression and growth inhibitor therapy. Once the obstruction is removed, there is no urgency to quickly resume oral feeding. Instead, enteral nutrition is performed. A pre-digested enteral nutrition solution with relatively low burden on the gastrointestinal tract, such as Beprid, is selected for enteral nutrition by 24-hour continuous nasal feeding with gradual increments. The patient’s malnutrition is basically improved before the full amount of enteral nutrition is implemented and the patient resumes feeding by mouth.
If the above conservative treatment plan always results in reoccurrence or repeated obstruction after feeding, surgical removal of the obstructed intestinal segment may be considered. For the segment of intestine without obvious obstruction, resection is not necessary to avoid short bowel syndrome. For short narrow intestinal segments without intestinal wall inflammation, the obstruction can also be eliminated by cutting and shaping the obstructed intestinal segment.
2.Intestinal perforation and intestinal fistula
Acute perforation mostly occurs at the proximal end of the obstruction and causes diffuse peritonitis, which requires emergency surgery. Surgery is mainly for infection control, including abdominal flushing, resection of the perforated intestinal segment, and continuous postoperative double trocar flushing. If the inflammation of the intestinal wall is severe and the patient’s general condition is poor, anastomosis of the intestinal canal may not be performed. After controlling the source of infection, a double stoma of the small intestine or colon is performed. After three months, the infection is controlled, the nutritional status improves, and the intestinal adhesions are loosened before reconstructive surgery of the GI tract is performed.
There is a pattern of intestinal fistulas in Crohn’s patients, with the first occurrence being mainly in the terminal ileum and mostly spontaneous fistulas, which are the only spontaneous fistulas seen in patients with intestinal fistulas. Patients with spontaneous fistulas are combined with abdominal abscess formation of varying degrees. In these patients, a damage-control staged surgical protocol of drainage of the abdominal abscess followed by resection of the intestinal fistula segment can be used.
Methods of abscess drainage include: puncture placement with retention drainage; open abdominal abscess with incision and placement + proximal stoma of the diseased intestinal canal. It is not advisable to remove the intestinal canal for one-stage anastomosis at the same time as the abscess is treated. Intestinal resection and intestinal anastomosis should be performed after the general condition of the patient has improved following drainage of the abscess.
Most recurrent cases are ileocolic anastomoses. Recurrence is classified as endoscopic recurrence, symptomatic recurrence and surgical complication recurrence. Therefore, regular endoscopy should be performed in postoperative patients, especially in patients with ileocolic anastomosis by ileocolic resection. Endoscopic recurrence can be defined by the finding of three or more ulcerated surfaces, at which time endoscopic treatment should be intensified to induce Crohn’s disease remission.
The Crohn’s Disease Activity Index score (CDAI) can also be used to assess whether Crohn’s disease is a symptomatic relapse. If it is a symptomatic relapse, treatment to induce remission should be initiated immediately. If an enterocutaneous fistula has developed, the ileocolic anastomosis can be reconstructed by reoperative resection after correction of malnutrition. Postoperatively, oral salazopyridine or ryanodine should be administered to prevent recurrence.
In severe cases, ileo-duodenal fistula, intestinal vesicouterine fistula, and small intestinal colonic fistula may occur. Short bowel syndrome can occur after the occurrence of endo-enteric fistula, where the patient presents with diarrhea, malnutrition and bleeding. Such patients should not be operated urgently after a clear diagnosis, but should be treated surgically after improving their general condition.
For ileoduodenal fistulas, the ileal segment or ileocecal segment can be removed and an ileo-ileal or ileocolonic anastomosis performed. For small duodenal fistulas, resection and repair of duodenal fistulas is feasible. For larger duodenal fistulas, jejuno-duodenal Roux-en-Y anastomosis is feasible. For small intestine intravesical fistula, resection of small intestine fistula with intestinal anastomosis is feasible, and for intravesical fistula, resection of fistula with bladder repair is feasible.
3. Gastrointestinal bleeding
Gastrointestinal bleeding often occurs in Crohn’s disease, and the symptoms are mainly hemorrhagic. It occurs mainly in patients with Crohn’s disease who have extensive lesions. Patients may present with bleeding due to ulcer rupture or bleeding due to ulcer erosion of blood vessels in the intestinal wall. Patients with Crohn’s disease have a predominantly ileal lesion, which is the main site of vitamin K absorption, so patients with Crohn’s disease tend to have a combination of impaired vitamin K absorption.
The impaired absorption of vitamin K leads to impaired synthesis of hepatic coagulation factors II, VII, IX, and X. This leads to impaired coagulation mechanisms, as evidenced by increased prothrombin time and international normalized ratio. As a result, bleeding in Crohn’s patients is characterized by easy bleeding that is not easily stopped. The bleeding is characterized by a large volume and a long duration.
For the combined gastrointestinal bleeding in Crohn’s disease, cold precipitation infusion and vitamin K injection can be used to promote the recovery of coagulation mechanism. For patients with more blood loss, the principle of damage control resuscitation should be followed, focusing on replenishing the full and comprehensive blood components and avoiding transfusion of concentrated red blood cells alone.
If bleeding does not improve even after the coagulation mechanism improves, DSA is feasible to understand whether there is large vessel bleeding, and if so, embolization can be used to stop the bleeding. If necessary, surgical hemostasis is performed. For patients with active Crohn’s disease without obvious hemorrhage, hormones and immunosuppressants can also be used in appropriate amounts to induce remission of Crohn’s disease, and this method can also effectively treat part of the patients with bleeding.
4, abdominal infection
Abdominal infections can occur in patients with spontaneous and recurrent fistulas. Anastomotic fistulas occurring immediately after surgery for Crohn’s disease can also be combined with abdominal infections. The most predominant form of abdominal infection is abdominal abscess, followed by diffuse peritonitis. The treatment measures for abdominal infection in Crohn’s disease include infection control measures of drainage, debridement and definitive treatment of the source of infection, rational antimicrobial drug use and immune modulation measures.
Second, the principles of perioperative management
1.Correction of malnutrition
Malnutrition in combination with Crohn’s disease is very common. The causes of malnutrition include: extensive intestinal lesions leading to impaired digestion and absorption of nutrients. Incomplete or complete intestinal obstruction leads to impaired absorption of energy and protein. Loss of intestinal fluid due to intestinal fistulas can also lead to impaired digestion and absorption of nutritional substrates. Malnutrition can be further exacerbated by increased catabolism due to stressors such as infection, perforation, and bleeding associated with Crohn’s disease. Long-term use of corticosteroids can inhibit protein anabolism and increase catabolism.
For malnutrition, if the intestinal function is normal, enteral nutrition via nasal feeding to the stomach can be considered. If gastric function is impaired, enteral nutrition support via nasal to intestine can be considered. Nutritional fluid should be given as a 24-hour continuous drip. It is advisable to choose in vitro pre-digested enteral nutrition solution as the main choice. The choice of this type of enteral nutrition fluid can rapidly and effectively improve the nutritional status, and can reduce the antigenicity of the nutrition fluid, while playing a role in inducing and maintaining remission of Crohn’s disease.
One study found that after a period of preoperative total parenteral nutrition support in Crohn’s patients with combined malnutrition, the preoperative clearly existing inflammatory lesions were surprisingly found to be significantly reduced or disappeared during surgery. Therefore, there is a role for the use of total parenteral nutrition specifically to induce remission of Crohn’s disease. The presumed mechanism was the elimination of irritation of the intestinal mucosa by foreign antigens.
Since then, it has been found that total enteral nutrition has a similar effect, and its effect is still evident in adolescent Crohn’s disease patients. In recent years, we have observed the effect of enteral nutrition in combination with ragweed to induce remission of Crohn’s disease, and found that enteral nutrition can significantly reduce the Crohn’s disease activity score (CDAI) and also significantly improve the nutritional status of Crohn’s disease patients. All Crohn’s patients who were admitted to our department used enteral nutrition in the perioperative period and achieved ideal results.
2. Eliminate the side effects of hormones and immunosuppressive drugs
The drug regimens for Crohn’s patients are 5-ASA, hormones, immunosuppressive drugs and anti-TNF antibodies according to their effects. These drugs increase in efficacy, but also increase in toxic effects. With the exception of 5-ASA, which has a mild toxic effect, other drugs that have a significant impact on surgical patients include immunosuppression resulting in decreased resistance to infection, hormonal-induced decrease in tissue synthesis and malnutrition.
Patients who develop surgical complications are mostly in the active phase of Crohn’s disease and are generally on these drugs. Others mistakenly treat infections associated with perforations and fistulas as Crohn’s activity and increase the risk of surgical site infections (SSI) and poor tissue healing after surgery. Therefore, patients on hormones and immunosuppressive drugs should be taken off such drugs for a period of time until their toxic effects have largely disappeared before surgery is performed. For surgical complications, relatively less invasive methods are used to relieve them first. Such as percutaneous abscess puncture and drainage, gastrointestinal decompression and other measures.
3. Correction of impaired coagulation mechanisms
As mentioned earlier, in patients with Crohn’s disease, the absorption of vitamin B and vitamin K is often impaired due to the lesions at the end of the ileum. Preoperatively, prothrombin time and international standardized ratio are routinely monitored. Any abnormalities in these indicators should be corrected promptly. In case of emergency surgery, cold sedimentation and platelet transfusion can be used as a temporary solution. After surgery, routine monitoring and prevention should also be carried out.
4.Rational use of anti-infective drugs
For Crohn’s disease patients operated for obstruction, the use of anti-infective drugs is mainly prophylactic, and anti-infective drugs can be used prophylactically according to the second class abdominal incision. For Crohn’s disease patients with combined intestinal fistulas, prophylactic anti-infective drugs can be used according to the third category of incisions, and preoperative fistula specimens can be taken for bacterial culture to guide the prophylactic use of drugs.
For patients with combined abscesses, antibacterial drugs should be administered according to the principles of treatment of complicated abdominal infections. This means obtaining pus for bacterial culture and then starting the empirical use of antimicrobial drugs, usually for Enterobacteriaceae. When the culture results are available, the decision to adjust the medication is made in conjunction with the response to treatment.
Patients with Crohn’s disease are more prone to fungal infections due to the combination of immunosuppression. Antifungal drugs may be used empirically in “superinfected” patients who are already on broad-spectrum antibiotics but still have fever. While obtaining various specimens of body fluids for bacterial culture, attention should also be paid to the results of fungal culture to prevent and treat fungal infections in a timely manner. Restore enteral nutrition is also an effective means to prevent and treat fungal infections.
5.Prevention of recurrence
One of the risks of Crohn’s disease after surgery for obstruction, perforation and intestinal fistula is recurrence. Recurrence is divided into immediate recurrence and delayed recurrence. Active use of parenteral and enteral nutritional support after surgery is an effective means of preventing recurrence of Crohn’s disease. After the intestinal function is restored, 5-ASA class and rhodopsin tablets can be used in time to prevent future recurrence. Postoperative colonoscopy and blood sedimentation should be reviewed regularly, and CDAI score should be performed for timely intervention to reduce the occurrence of surgical complications.
Conclusion
With the increase in the number of patients with Crohn’s disease and better understanding, more and more patients with Crohn’s disease will require surgical intervention due to surgical complications. Surgeons should be familiar with the rules for the development of surgical complications of this disease and intervene in a timely manner to effectively prevent further deterioration of Crohn’s disease with complications such as intestinal obstruction, perforation, and intestinal fistula.