Regeneration of Transected Recurrent Laryngeal Nerve Using Hybrid-Transplantation of Skeletal Muscle-Derived Stem Cells and Bioabsorbable Scaffold

Hybrid transplantation of skeletal muscle-derived multipotent stem cells (Sk-MSCs) and bioabsorbable polyglyconate (PGA) felt was studied as a novel regeneration therapy for the transected recurrent laryngeal nerve (RLN). Sk-MSCs were isolated from green fluorescence protein transgenic mice and then expanded and transplanted with PGA felt for the hybrid transplantation (HY group) into the RLN transected mouse model. Transplantation of culture medium (M group) and PGA + medium (PGA group) were examined as controls. After eight weeks, trans-oral video laryngoscopy demonstrated 80% recovery of spontaneous vocal-fold movement during breathing in the HY group, whereas the M and PGA groups showed wholly no recoveries. The Sk-MSCs showed active engraftment confined to the damaged RLN portion, representing favorable prevention of cell diffusion on PGA, with an enhanced expression of nerve growth factor mRNAs. Axonal re-connection in the HY group was confirmed by histological serial sections. Immunohistochemical analysis revealed the differentiation of Sk-MSCs into Schwann cells and perineurial/endoneurial cells and axonal growth supportive of perineurium/endoneurium. The number of axons recovered was over 86%. These results showed that the stem cell and cytokine delivery system using hybrid transplantation of Sk-MSCs/PGA-felt is a potentially practical and useful approach for the recovery of transected RLN.

Polyglycolic Acid Felt Sealing Method for Prevention of Bleeding Related to Endoscopic Submucosal Dissection in Patients Taking Antithrombotic Agents

Background and Study Aims. When performing endoscopic submucosal dissection (ESD) for patients on antithrombotic agents, the frequency of delayed bleeding is expected to increase. The endoscopic polyglycolic acid (PGA) felt and fibrin glue sealing method could be a new method for prevention of delayed bleeding.Patients and Methods. The safety and efficacy of the endoscopic tissue sealing method with PGA sheets and fibrin glue for the prevention of post-ESD bleeding were examined in 104 patients taking antithrombotic agents. During the study period, 70 patients taking antithrombotic agents did not undergo the sealing method, 36 patients discontinued antithrombotic agents, and 724 patients had not received antithrombotic therapy.Results. Delayed bleeding rates were 3.8% (4/104) in the sealing group, 12.9% (9/70) in the nonsealing group, 8.3% (3/36) in the discontinuation group, and 4.6% (33/724) in the nonantithrombotic therapy group. Thus, the delayed bleeding rate was significantly lower in the sealing group than in the nonsealing group and comparable to that in the nonantithrombotic therapy group.Conclusions. This PGA felt and fibrin glue sealing method might become a promising post-ESD bleeding prevention method in patients taking antithrombotic agents (UMIN000013990,UMIN000013993).