Composite tissue allotransplantation and dysregulation in tissue repair and regeneration: a role for mesenchymal stem cells.

Vascularized composite tissue allotransplantation is a rapidly evolving area that has brought technological advances to the forefront of plastic surgery, hand surgery, and transplant biology. Composite tissue allografts (CTAs) may have profound functional, esthetic, and psychological benefits, but carry with them the risks of life-long immunosuppression and the inadequate abilities to monitor and prevent rejection. Allografts may suffer from additional insults further weakening their overall benefits. Changes in local blood flow, lack of fully restored neurologic function, infection, inflammation with subsequent dysregulated regenerative activity, and paucity of appropriate growth factors may all be involved in reducing the potential of CTAs and therefore serve as new therapeutic targets to improve outcomes. Strategies involving minimized immunosuppression and pro-regenerative therapy may provide a greater path to optimizing long-term CTA function. One such strategy may include mesenchymal stem cells (MSCs), which can provide unique anti-inflammatory and pro-regenerative effects. Insights gained from new studies with MSCs on composite allografts, advances in tissue regeneration reported in other MSC-based clinical studies, as well as consideration of newly described capacities of MSCs, may provide new regenerative based strategies for the care of CTAs.

A comparison of robotic, laparoscopic, and hand-sewn intestinal sutured anastomoses performed by residents.

BACKGROUND: Robotic surgery offers all the advantages of laparoscopy with additional increased accuracy. The use of robotic surgery has increased in the past 5 years. It has proven particularly useful in complex surgical procedures such as intracorporeal intestinal anastomosis. As the prevalence of robotic surgery increases, so will the need for residents to be able to perform surgery using the robotic system. Our goal was to compare hand-sewn, laparoscopic, and robotic suturing techniques performed by midlevel residents using a porcine intestinal model. METHODS: Fifteen residents unfamiliar with the robotic suturing technique participated in performing an initial hand-sewn suture line and then were randomized with cross-over to laparoscopic or robotic suturing. Completion time, leak pressure, number of sutures per cm, and difficulty level were assessed. RESULTS: The mean leak pressure for hand-sewn, laparoscopic, and robotic suturing was 9.5, 3.2, and 11.4 mm Hg, respectively. The laparoscopic group had 6 and the robotic group had 1 suture line that was inadequate for testing. Suture breakage was common in the robotic group. The anastomosis was considered hard by 92% in the laparoscopic group versus 17% in the robotic group. The time it took to complete 1 cm of anastomosis was .9, 8.7, and 8.3 minutes for hand-sewn, laparoscopic, and robotic suturing, respectively. CONCLUSION: The robotic suture line performed by midlevel residents was superior to laparoscopy, although the time for anastomosis was equivalent.

Muscle fragment welding for control of massive presacral bleeding during rectal mobilization: a review of eight cases.

INTRODUCTION: Although massive presacral bleeding during rectal mobilization is uncommon, it can rapidly destabilize a patient. Traditional attempts at control include tamponade with pelvic packing and application of sacral thumbtacks. The aim of this review is to describe the anatomic basis of injury and summarize our experience with this challenging problem, with emphasis on the simple, readily available, effective technique of rectus abdominis muscle fragment welding. METHODS: A retrospective review of eight patients who underwent muscle fragment welding for presacral bleeding incurred during rectal mobilization was undertaken. This technique involves harvesting a small piece of rectus abdominis muscle, which is held in place with a forceps to occlude the bleeding site. Electrocautery adjusted to the highest setting is then applied to the forceps to "weld" closed the bleeding point. RESULTS: Control of presacral bleeding was achieved in all eight patients (3 males) with this technique without complications attributable to this method. Previous attempts at pelvic packing failed in all eight patients. CONCLUSION: Muscle fragment welding is a safe, readily available, and highly effective method of controlling massive presacral bleeding.

Virtual reality: new method of teaching anorectal and pelvic floor anatomy.

PURPOSE: A clear understanding of the intricate spatial relationships among the structures of the pelvic floor, rectum, and anal canal is essential for the treatment of numerous pathologic conditions. Virtual-reality technology allows improved visualization of three-dimensional structures over conventional media because it supports stereoscopic-vision, viewer-centered perspective, large angles of view, and interactivity. We describe a novel virtual reality-based model designed to teach anorectal and pelvic floor anatomy, pathology, and surgery. METHODS: A static physical model depicting the pelvic floor and anorectum was created and digitized at 1-mm intervals in a CT scanner. Multiple software programs were used along with endoscopic images to generate a realistic interactive computer model, which was designed to be viewed on a networked, interactive, virtual-reality display (CAVE or ImmersaDesk). A standard examination of ten basic anorectal and pelvic floor anatomy questions was administered to third-year (n = 6) and fourth-year (n = 7) surgical residents. A workshop using the Virtual Pelvic Floor Model was then given, and the standard examination was readministered so that it was possible to evaluate the effectiveness of the Digital Pelvic Floor Model as an educational instrument. RESULTS: Training on the Virtual Pelvic Floor Model produced substantial improvements in the overall average test scores for the two groups, with an overall increase of 41 percent (P = 0.001) and 21 percent (P = 0.0007) for third-year and fourth-year residents, respectively. Resident evaluations after the workshop also confirmed the effectiveness of understanding pelvic anatomy using the Virtual Pelvic Floor Model. CONCLUSION: This model provides an innovative interactive educational framework that allows educators to overcome some of the barriers to teaching surgical and endoscopic principles based on understanding highly complex three-dimensional anatomy. Using this collaborative, shared virtual-reality environment, teachers and students can interact from locations world-wide to manipulate the components of this model to achieve the educational goals of this project along with the potential for virtual surgery.