Is bowel anastomosis indicated in a patient with hyperglycemia (elevated Hemoglobin A1c (HbA1c))?

From the Guidelines

Bowel anastomosis should not be performed on a patient with hyperglycemia (elevated Hemoglobin A1c (HbA1c)) without first optimizing their glucose control, aiming for an HbA1c below 8% (<64.0 mmol/L) whenever possible, as recommended by the most recent guidelines 1. This is because an elevated HbA1c indicates poor glycemic control, which significantly increases the risk of surgical complications, particularly poor wound healing, anastomotic leakage, and infection. Before elective surgery, it is crucial to work on optimizing the patient's glucose control with appropriate diabetes management, which may require several weeks to months of intensive diabetes management including medication adjustment (potentially including insulin therapy), dietary modifications, and close monitoring 1. During this optimization period, consider consulting with an endocrinologist to establish an effective diabetes management plan. If surgery cannot be delayed due to urgent indications, ensure extremely vigilant perioperative glucose monitoring, aggressive insulin management, and heightened surveillance for complications, following the guidelines for blood glucose goals in the perioperative period of 100–180 mg/dL (5.6–10.0 mmol/L) within 4 h of the surgery 1. Key considerations in the perioperative management include holding metformin on the day of surgery, discontinuing SGLT2 inhibitors 3–4 days before surgery, and adjusting insulin doses, such as reducing NPH insulin to one-half of the dose or long-acting basal insulin analogs 1. The rationale for postponing surgery when possible is that hyperglycemia impairs neutrophil function, increases oxidative stress, promotes inflammation, and compromises microvascular circulation - all factors that directly interfere with tissue healing and anastomotic integrity. Therefore, prioritizing the optimization of glucose control before proceeding with bowel anastomosis is essential to minimize the risk of complications and ensure the best possible outcomes for the patient, in line with the latest recommendations from Diabetes Care 1.

From the Research

Bowel Anastomosis in Patients with Hyperglycemia

• The decision to perform a bowel anastomosis in a patient with hyperglycemia (elevated Hemoglobin A1c (HbA1c)) should be made with caution, as elevated HbA1c levels are associated with an increased risk of postoperative complications, including anastomotic leaks and wound infections 2.
• A study found that patients with a high HbA1c had a greater risk of anastomotic leaks, wound infections, major complications, and overall complications after elective major abdominal surgery 2.
• The optimal HbA1c threshold for bowel anastomosis is not well established, but an HbA1c between 6% and 7% is associated with higher risks of anastomotic leaks, wound infections, major complications, and overall postoperative complications 2.
• Surgeons can control the technique used for creating anastomoses, and protecting and ensuring a vigorous blood supply is fundamental, as is mobilizing bowel completely, and employing adjunctive techniques to attain reach without tension 3.

Anastomotic Techniques and Hyperglycemia

• There are numerous ways to create anastomoses, with variations on the segment and configuration of bowel used, as well as the materials used and surgical approach 3.
• Despite numerous studies on the optimal techniques for anastomoses, no one method has prevailed, and surgeons should focus on adhering to good technique and being comfortable with several configurations for a variety of conditions 3.
• A novel linear magnetic compression anastomosis device has been shown to be feasible, safe, and effective for weight loss and type 2 diabetes resolution in patients with class III obesity, with no anastomotic bleeding, leakage, stricture, or mortality reported 4.

Management of Hyperglycemia in Surgical Patients

• The management of hyperglycemia in surgical patients is crucial to minimize the risk of postoperative complications, and a discharge strategy based on admission HbA1c can guide therapy in general medicine and surgery patients with type 2 diabetes 5.
• The co-administration of sitagliptin with metformin has been shown to be safe and effective in improving glycemic control after hospital discharge in patients with type 2 diabetes 5.