Comparison of the Effects of Neostigmine and Sugammadex on Colonic Anastomotic Strength in Rats

Multilayered Human Skeletal Muscle Myoblast Sheets Promote the Healing Process After Colonic Anastomosis in Rats

Colorectal anastomotic leakage is one of the most feared and fatal complications of colorectal surgery. To date, no external coating material that can prevent anastomotic leakage has been developed. As myoblasts possess anti-inflammatory capacity and improve wound healing, we developed a multilayered human skeletal muscle myoblast (HSMM) sheet by periodic exposure to supraphysiological hydrostatic pressure during repeated cell seeding. We assessed whether the application of an HSMM sheet can promote the healing process after colonic anastomosis. Partial colectomy and insufficient suturing were employed to create a high-risk colo-colonic anastomosis model in 60 nude rats. Rats were divided into a control group (n = 30) and an HSMM sheet group (n = 30). Macroscopic findings, anastomotic bursting pressure, and histology at the colonic anastomotic site were evaluated on postoperative day (POD) 3, 5, 7, 14, and 28. The application of an HSMM sheet significantly suppressed abscess formation at the anastomotic site compared to the control group on POD3 and 5. The anastomotic bursting pressure in the HSMM sheet group was higher than that in the control group on POD3 and 5. Inflammatory cell infiltration in the HSMM sheet group was significantly suppressed compared to that in the control group throughout the time course. Collagen deposition in the HSMM sheet group on POD3 was significantly abundant compared to that in the control group. Regeneration of the mucosa at the colonic anastomotic site was promoted in the HSMM sheet group compared to that in the control group on POD14 and 28. Immunohistochemical analysis demonstrated that surviving cells in the HSMM sheet gradually decreased with postoperative time and none were detected on POD14. These results suggest that the application of a multilayered HSMM sheet may prevent postoperative colonic anastomotic leakage.

The effects of acetylcholinesterase inhibitors on morbidity after general anesthesia and surgery

Non-depolarizing neuromuscular blocking agents are used during general anesthesia to facilitate intubation and optimize surgical conditions. When patients leave the operating room after surgery, postoperative residual neuromuscular block occurs frequently, increasing vulnerability to respiratory complications such as hypoxemia and unplanned postoperative mechanical ventilation. To restore neuromuscular transmission and skeletal muscle strength, anesthesiologists typically administer peripherally acting acetylcholinesterase inhibitors such as neostigmine. However, neostigmine's desirable effects have a narrow therapeutic range. Even at recommended dose (15-50 μg/kg), neostigmine induces nicotinic (upper airway muscle weakness leading to dysphagia and upper airway obstruction, and decreased maximum inspiratory airflow) and muscarinic (blurred vision, bronchial constriction, abdominal cramping and nausea) side effects. Recent data have questioned as to whether neostigmine reversal of neuromuscular blockade improves relevant patient outcomes such as postoperative respiratory and perioperative cardiovascular complications. A central strategy to avoid side effects of neuromuscular blocking agents is their judicious use based on quantitative monitoring of neuromuscular transmission using repetitive peripheral nerve stimulation (train-of-four ratio). Peripherally acting acetylcholinesterase inhibitors such as neostigmine should then only be administered when indicated and dosed based on results of the train-of-four ratio.