Sharma, Ayushman

Biliary complications (strictures and leaks) represent major limitations in living donor liver transplantation. Mesenchymal stem cells (MSCs) are a promising modality to prevent biliary complications because of immunosuppressive and angiogenic properties. Our goal was to evaluate the safety of adipose‐derived MSC delivery to biliary anastomoses in a porcine model. Secondary objectives were defining the optimal method of delivery (intraluminal versus extraluminal) and to investigate MSC engraftment, angiogenesis, and fibrosis. Pigs were divided into 3 groups. Animals underwent adipose collection, MSC isolation, and expansion. Two weeks later, animals underwent bile duct transection, reanastomosis, and stent insertion. Group 1 received plastic stents wrapped in unseeded Vicryl mesh. Group 2 received stents wrapped in MSC‐seeded mesh. Group 3 received unwrapped stents with the anastomosis immersed in an MSC suspension. Animals were killed 1 month after stent insertion when cholangiograms and biliary tissue were obtained. Serum was collected for liver biochemistries. Tissue was used for hematoxylin‐eosin and trichrome staining and immunohistochemistry for MSC markers (CD44 and CD34) and for a marker of neoangiogenesis (CD31). There were no intraoperative complications. One pig died on postoperative day 3 due to acute cholangitis. All others recovered without complications. Cholangiography demonstrated no biliary leaks and minimal luminal narrowing. Surviving animals exhibited no symptoms, abnormal liver biochemistries, or clinically significant biliary stricturing. Group 3 showed significantly greater CD44 and CD34 staining, indicating MSC engraftment. Fibrosis was reduced at the anastomotic site in group 3 based on trichrome stain. CD31 staining of group 3 was more pronounced, supporting enhanced neoangiogenesis. In conclusion, adipose‐derived MSCs were safely applied to biliary anastomoses. MSCs were locally engrafted within the bile duct and may have beneficial effects in terms of fibrosis and angiogenesis.

Objective: Several techniques are described in the literature for nasal septal perforation repair. Most of these involve interposition grafts in conjunction with local pedicled mucosal flaps. The following article describes our experience using acellular dermis as a bioscaffold to support the regrowth of nasal septal mucosa by secondary intention. Methods: Retrospective chart review of all patients who underwent repair of nasal septal perforations by the senior author using acellular dermis placed between the 2 sides of the perforation and covered with silastic splints to allow for mucosalization. Results: Thirteen patients underwent nasal septal perforation repair using this technique. All perforations repaired were under 2 cm in greatest dimension. Two-thirds of patients had complete closure of the perforation upon initial use of bioscaffolding technique. The remaining third achieved near-total closure with bioscaffolding technique and were able to be completely closed with a single additional procedure. Conclusions: Acellular dermis offers an alternative to most currently described complex flaps. The method can be used in patients with defects less than 2 cm, but initial data suggest caution when using in those with wound healing impediments. This technique is also an excellent choice for patients with multiple small septal perforations.