Effect of Kono-S anastomosis on reducing postoperative recurrence rates in Crohn's disease: a systematic review and meta-analysis

BACKGROUND

Kono-S anastomosis has gained increasing interest although evaluation of its impact on reducing Crohn's recurrence shows conflicting results. This study aimed to evaluate the short- and long-term outcomes for patients with Crohn's disease requiring surgery with Kono-S compared to conventional anastomosis.

METHODS

A systematic review and meta-analysis included patients with Crohn's disease treated with bowel resection and Kono-S anastomosis reconstruction versus a comparator arm of conventional anastomosis technique. Recurrence outcomes examined were endoscopic recurrence rates, mean postoperative Rutgeerts score, surgical recurrence, clinical recurrence, and postoperative biologics use. Short-term postoperative outcomes include anastomotic leaks, surgical site infection, postoperative ileus, and mean operative time.

RESULTS

A total of 873 studies were identified with 15 remaining after abstract review encompassing 1501 patients, 765 with Kono-S and 736 with conventional anastomosis. Recurrence was significantly lower in the Kono-S arm, with endoscopic recurrence rates of 41% vs 48% (RR 0.86, 95% CI 0.73-1.00, p = 0.05) and surgical recurrence rates of 2.7% vs 21.0% (RR 0.13, 95% CI 0.06-0.30, p < 0.001). There was a significantly lower anastomotic leak rate in the Kono-S arm when compared to conventional anastomosis, 1.7% vs 4.9% (RR 0.37, 95% CI 0.19-0.74, p = 0.005). Mean operative time was similar between both groups.

CONCLUSIONS

Kono-S is a safe and feasible anastomotic technique with lower rates of endoscopic and surgical postoperative recurrence. While we await further trials to substantiate this benefit, Kono-S anastomosis should be considered as an important tool in the armamentarium of a surgeon in anastomotic construction to reduce recurrence.

Positive resection margins in Crohn's disease are a relevant risk factor for postoperative disease recurrence

Postoperative disease recurrence in Crohn's disease represents a relevant issue despite recent advancements in surgical and medical therapies. Additional criteria are necessary to improve the identification of patients at risk and to enable selective therapeutic approaches. The role of resection margins on disease recurrence remains unclear and general recommendations are lacking. A single-center retrospective analysis was performed including all patients who received ileocecal resection due to Crohn's disease. Resection margins were analyzed by two independent pathologists and defined by histopathological criteria based on previous consensus reports. 158 patients were included for analysis with a median follow up of 35 months. While postoperative morbidity was not affected, positive resection margins resulted in significantly increased rates of severe endoscopic recurrence at 6 months (2.0% versus 15.6%, p = 0.02) and overall (4.2% versus 19.6%, p = 0.001), which resulted in significantly increased numbers of surgical recurrence (0% versus 4.5%, p = 0.04). Additionally, positive margins were identified as independent risk factor for severe endoscopic disease recurrence in a multivariate analysis. Based on that, positive margins represent an independent risk factor for postoperative endoscopic and surgical disease recurrence. Prospective studies are required to determine whether extended resection or postoperative medical prophylaxis is beneficial for patients with positive resection margins.

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.

Postoperative Use of Biologics was Less Common among Patients with Crohn's Disease With Emergent/Urgent Versus Elective Intestinal Resection

Background & Aims

Given the risk of intestinal resection for Crohn's disease, postoperative treatment may be informed by several risk factors, including resection type. We compared postoperative treatment strategies for Crohn's disease between emergent/urgent versus elective resection.

Methods

We identified patients with intestinal resection for Crohn's disease between 2002-2018 using the MarketScan databases. We classified emergent/urgent resections as those occurring after emergency department admission or after the second day of admission. We estimated adjusted risk differences for the association between resection type (emergent/urgent versus elective) and 6-month postoperative medication strategy (biologic monotherapy, biologic combination therapy with an immunomodulator, immunomodulator monotherapy, other non-biologic medication for Crohn's [5-aminosalicylates, antibiotics, corticosteroids], or no medications for Crohn's).

Results

During 6 months after resection among 4,187 patients, 23% received biologic monotherapy, 6% received combination therapy, 16% received immunomodulator monotherapy, and 36% received other non-biologics. Compared to elective resection, emergent/urgent resection was associated with more common use of "other non-biologic" medications (risk difference 6.4%; 95% confidence interval [CI] 2.8%, 10.0%), but less common use of biologic monotherapy (risk difference -3.2%; 95% CI -6.2%, -0.1%) and no medications (risk difference -3.6%; 95% CI -6.6%, -0.6%).

Conclusions

Although patients with emergent/urgent resection may benefit from more aggressive postoperative therapy, there was evidence that emergent/urgent resection was more associated than elective resection with postoperative use of non-biologics for Crohn's disease. Future studies of treatment patterns and comparative effectiveness of postoperative treatment strategies for Crohn's patients should consider these differences between resection types, which may be important drivers of longer-term outcomes.

Surgical Treatment for Crohn's Disease: A Role of Kono-S Anastomosis in the West

More than 80% of patients with Crohn's disease (CD) will require surgical intervention during their lifetime, with high rates of anastomotic recurrence and stenosis necessitating repeat surgery. Current data show that pharmacotherapy has not significantly improved the natural history of postoperative clinical and surgical recurrence of CD. In 2003, antimesenteric hand-sewn functional end-to-end (Kono-S) anastomosis was first performed in Japan. This technique has yielded very desirable outcomes in terms of reducing the incidence of anastomotic surgical recurrence. The most recent follow-up of these patients showed that very few had developed surgical recurrence. This new approach is superior to stapled functional end-to-end anastomosis because the stumps are sutured together to create a stabilizing structure (a "supporting column"), serving as a supportive backbone of the anastomosis to help prevent distortion of the anastomotic lumen due to disease recurrence and subsequent clinical symptoms. This technique requires careful mesenteric excision for optimal preservation of the blood supply and innervation. It also results in a very wide anastomotic lumen on the antimesenteric side. The Kono-S technique has shown efficacy in preventing surgical recurrence and the potential to become the new standard of care for intestinal CD.