"Mesentery-based surgery" to prevent surgical recurrence in Crohn's disease: from basics to surgical practice

Aspects Towards the Anastomotic Healing in Crohn’s Disease: Clinical Approach and Current Gaps in Research

Anastomotic leakage is a major complication in gastrointestinal and colorectal surgery and its occurrence increases morbidity and mortality. Its incidence is even higher in Crohn’s disease surgeries. Several authors have identified factors involved in the pathophysiology of anastomotic leak in the literature, aiming to reduce its occurrence and, therefore, improve its surgical treatment. Surgical technique is the most discussed topic in studies on guiding the performance of side-to-side stapled anastomosis. Preoperative nutritional therapy also has been shown to reduce the risk of anastomotic leakage. Other factors remain controversial – immunomodulator use and biologic therapy, antibiotics, and gut microbiota – with studies showing a reduction in the risk of complication while other studies show no correlation. Although mesenteric adipose tissue has been related to disease recurrence, there is no evidence in the literature that it is related to a higher risk of anastomotic leakage. Further exploration on this topic is necessary, including prospective research, to support the development of techniques to prevent anastomotic leakage, in this way benefiting the inflammatory bowel disease patients who have to undergo a surgical procedure.

Intriguing Role of the Mesentery in Ileocolic Crohn's Disease

Crohn's disease (CD) is a chronic relapsing inflammatory bowel disease with unknown etiology. Up to 80% of patients will eventually require surgery throughout their lifetime, and often repeated resections are required for disease recurrence. Observations of “creeping fat” surrounding the diseased intestine renewed interest in the mesentery, recently defined as an organ with endocrine and immune functions. According to the inside-out model, the mesentery may be primarily affected in CD and subsequent cause alterations in the mucosa. Recently, lower surgical recurrence rates have been reported with en-bloc excision of the mesentery adjoining the diseased intestine. Results of ongoing randomized controlled trials may clarify the role of the mesentery in CD and possibly lead to its adoption as standard during surgery for Crohn's disease.

Surgical Strategies to Reduce Postoperative Recurrence of Crohn's Disease After Ileocolic Resection

Postoperative recurrence after ileocaecal resection for fibrostenotic terminal ileal Crohn's disease is a significant issue for patients as it can result in symptom recurrence and requirement for further surgery. There are very few modifiable factors, aside from smoking cessation, that can reduce the risk of postoperative recurrence. Until relatively recently, the surgical technique used for resection and anastomosis had little or no impact on postoperative recurrence rates. Novel surgical techniques such as the Kono-S anastomosis and extended mesenteric excision have shown promise as ways to reduce postoperative recurrence rates. This manuscript will review and discuss the evidence regarding a range of surgical techniques and their potential role in reducing disease recurrence. Some of the techniques have been shown to be associated with significant benefits for patients and have already been integrated into the routine clinical practice of some surgeons, while other techniques remain under investigation. Current techniques such as resection of the mesentery close to the intestine and stapled side to side anastomosis are being challenged. It is looking more likely that surgeons will have a major role to play when it comes to reducing recurrence rates for patients undergoing ileocaecal resection for Crohn's disease.

Surgical features to reduce anastomotic recurrence of Crohn's disease that requires reoperation: a systematic review

Anastomotic recurrence after intestinal resection is one of the main embarrassing problems encountered during Crohn's disease (CD) management. This complication is often associated with an expected consequence, mainly a multiple intestinal resection. This systematic review evaluates published evidence on surgical features to reduce surgical recurrence after bowel resection and provide surgeons with recommendations based on published evidence. We conducted bibliographic research on September 05, 2020, through PubMed, Cochrane database, and Google scholar. We retained meta-analysis, randomized clinical trials, and controlled clinical trials. The strength of clinical data and subsequent recommendations were graded according to the Oxford Centre for Evidence-Based Medicine. Fourteen articles were retained. Early resection reduces surgical relapse and the need for additional medical treatment. There was no difference between conventional and laparoscopic bowel resection. Mesenteric excision seems to reduce surgical recurrence. Stapled side-to-side anastomosis reduces surgical recurrence. However, no difference was observed between Kono-S anastomosis ensure at least similar anastomotic recurrence rate compared to conventional anastomosis. Surgical recurrence was reduced after bowel resection when compared to stricturoplasty. There was no difference between the one and two steps resection. Several surgical features have been investigated. Some of them were unanimously found to be effective in lengthening the disease-free relapse. However, others are still controversial.

Mesenteric excision surgery or conservative limited resection in Crohn's disease: study protocol for an international, multicenter, randomized controlled trial

Background

The structures of the mesentery including adipose tissue, nerves, and lymphatics play an important role in the pathogenesis and disease progression of Crohn’s disease (CD). Conventional surgical resection for CD usually does not involve resecting the mesentery en bloc with the specimen. This contrasts with complete mesocolic excision (CME) in colorectal cancer, which involves radical resection of the mesentery. Preliminary evidence from smaller studies suggests that applying the principle of mesocolic excision to CD surgery may reduce the risk of postoperative recurrence. This randomized controlled trial is designed to test whether applying the principles of mesocolic excision to CD results in reduced postoperative recurrence. It also aims to evaluate intra- and postoperative morbidity between the two approaches.

Methods

This international, multicenter, randomized controlled trial will randomize patients (n = 116) scheduled to undergo primary ileocolic resection to either receive extensive mesenteric excision (EME) or conventional ileocolic resection with limited mesenteric excision (LME). Five sites will recruit patients in three countries. In the EME group, the mesentery is resected following CME, while avoiding the root region, i.e., 1 cm from the root of the ileocolic artery and vein. In the LME group, the mesentery is retained, i.e., “close shave” or < 3 cm from the border of bowel. The primary end point will be surgical recurrence after surgery. The secondary end points will be the postoperative endoscopic and clinical recurrence, and intra- and postoperative morbidity. Demographics, risk factors, laboratory investigations, endoscopy, postoperative prophylaxis and imaging examination will be assessed. Analysis of the primary outcome will be on an intention-to-treat basis.

Discussion

If mesocolic excision in CD reduces postoperative disease recurrence and does not increase morbidity, this trial has the potential to change practice and reduce recurrence of CD after surgical resection.

Trial registration

Clinical Trials.gov, ID: NCT03769922. Registered on February 27, 2019.