The Application of an Omentum Graft or Flap in Spinal Cord Injury

Background: Spinal cord injury (SCI) causes a primary injury at the lesion site and triggers a secondary injury and prolonged inflammation. There has been no definitive treatment till now. Promoting angiogenesis is one of the most important strategies for functional recovery after SCI. The omentum, abundant in blood and lymph vessels, possesses the potent ability of tissue regeneration. Methods: The present work examines the efficacy of autologous omentum, either as a flap (with vascular connection intact) or graft (severed vascular connection), on spinal nerve regeneration. After contusive SCI in rats, a thin sheath of omentum was grafted to the injured spinal cord. Results: Omental graft improved behavior scores significantly from the 3rd to 6th week after injury (6th week, 5.5 ± 0.5 vs. 8.6 ± 1.3, p < 0.05). Furthermore, the reduction in cavity and the preservation of class III β-tubulin-positive nerve fibers in the injury area was noted. Next, the free omental flap was transposed to a completely transected SCI in rats through a pre-implanted tunnel. The flap remained vascularized and survived well several weeks after the operation. At 16 weeks post-treatment, SCI rats with omentum flap treatment displayed the preservation of significantly more nerve fibers (p < 0.05) and a reduced injured cavity, though locomotor scores were similar. Conclusions: Taken together, the findings of this study indicate that treatment with an omental graft or transposition of an omental flap on an injured spinal cord has a positive effect on nerve protection and tissue preservation in SCI rats. The current data highlight the importance of omentum in clinical applications.

Behavior of free omental grafts without vascular anastomosis implanted in cat’s experimental wounds

ABSTRACT: It is known that skin healing in cats is slower and has a higher complication rate than in dogs, what leads to search for new resources to enhance this process. Omentum properties in the aid of tissue repair are known and, among the forms of extraperitoneal omentalization, the use of free omental grafts without vascular anastomosis is advantageous, but little studied; there is no knowledge about its effect on skin healing, nor if it’s still viable when implanted in the subcutaneous space. Thus, the present study aimed to describe possible alterations produced by free omental graft without anastomosis inserted in the subcutaneous space, by means of macroscopic clinical analysis of the implantation region in cats. Twenty intact female cats were divided into two groups (Group 1: treated animals; Group 2: controls) of similar size. All animals were subjected to ovariosalpingohysterectomy (OSH) prior to the induction of an experimental wound for the implantation of the omental graft. Wounds were evaluated on days 1, 2, 4, 8, and 15 postsurgery and then weekly until no lesions were noted. Data regarding color, consistency, presence or absence of crusts, wound resistance, and volume measurements were recorded. There was activation of the omentum on the 4th day of evaluation with reduction of hemorrhage and an increase in the resistance to traction of the experimental wound. We concluded that the omentum without vascular anastomosis is capable of maintaining its viability and exert positive influence on the repair process without showing deleterious signs on the implantation site.

Angiogenic capabilities of omentomyelopexy for injured spinal cord revascularization

Introduction/Objective. Increasing incidence of spinal cord injuries presents a very important issue. These patients are usually very young, treatment is very tough, long, expensive and, in general, of little success rate. The aim of this study was to evaluate the angiogenic potential of the omental graft in spinal cord revascularization after the injury. Methods. The study included 19 patients, who underwent recurrent surgical procedure for pain syndrome or surgical complication, and one patient in whom angiography revealed no flow in distal part of omental graft. Results. Our study confirmed angiogenic capabilities of omental graft placed in the course of omentomyelopexy for the injured spinal cord revascularization, macroscopically and histopathologically. Study results are limited due to inclusion of patients, only when the postoperative period was complicated. Conclusion. Our study provides some insight into the angiogenic capabilities. Although, further (likely less invasive) studies are needed to provide more insight into omental angiogenesis and to include patients in whom the procedure went well.

Lamellar keratoplasty in rabbits using an allogeneic free omental graft and omentum-derived mesenchymal cells associated with the canine amniotic membrane

ABSTRACT: The objective of this research was to evaluate the clinical and microscopic effects in rabbits of lamellar keratoplasty using allogeneic omentum associated with canine amniotic membrane (AM). Rabbits were divided into two groups: one received the allogeneic free omental graft covered with the AM (OM-graft group), while the other received the AM graft containing omental mesenchymal cells (OM-cell group). Clinical signs were evaluated on different postoperative days. After the clinical assessments, the rabbits were euthanized and their corneas were obtained for histopathology and immunohistochemistry (Ki-67, marker for proliferation). Both groups showed chemosis, blepharospasm, eye discharge, hyperemia, and corneal opacity/edema. Neovascularization was observed in the OM-cell group. Histopathological evaluation revealed epithelial islands within the stroma of OM-cell samples. Thirty days after surgery, complete corneal re-epithelialization had occurred in both groups. The OM-cell group showed more Ki-67 positive cells. The free omentum and its cells, combined with the AM, contributed to corneal repair, a process that was completed 30 days after lamellar keratoplasty.

Augmentation of diaphyseal fractures of the radius and ulna in toy breed dogs using a free autogenous omental graft and bone plating

SummaryObjectives: Evaluation of the short-term outcome, duration of bone healing, and complications following bone plate fixation in dogs weighing [uni2264]6 kg, with and without the use of a free autogenous greater omental graft (OG).Materials and methods: A retrospective clinical study reviewed the medical records of 25 dogs of body weight <6 kg with mid to distal diaphyseal fractures of the radius and ulna (29 fractures) treated with open reduction bone plate fixation. Thirteen out of 29 fractures were implanted with an additional 2–3 cm3 OG lateral, cranial, and medial to the fracture site, adjacent to the bone plate.Results: Median time to radiographic healing in OG fractures (n = 11) was 70 days (range 28–98) compared to 106 days (range: 56–144) in non-OG grafted fractures (n = 14). The OG dogs had no major complications; minor complications included oedema, erythema, and mild osteopenia. Six of the eight non-OG dogs for which follow-up could be obtained developed osteopenia necessitating implant removal, four of which re-fractured the radius one to five months after implant removal, with one dog re-fracturing the limb a second time and resulting in amputation. Telephone follow-up of owners of OG dogs (n = 11) three to 15 months (median 10) post-surgery did not identify any signs of lameness or other complications. Owners of the non-OG dogs (n = 8) reported that there were not any signs of lameness six to 48 months (median 36) post-surgery.Clinical relevance: Free autogenous omen-tal grafting of diaphyseal fractures of the radius and ulna was associated with radial and ulnar healing with minimal complications in dogs weighing less than 6 kg.