Photosealed Neurorrhaphy Using Autologous Tissue Rossi, Nicolò; Bejar-Chapa, Maria; Giorgino, Riccardo ...
International journal of molecular sciences,
06/2024, Letnik:
25, Številka:
13
Journal Article
Recenzirano
Photochemical sealing of a nerve wrap over the repair site isolates and optimizes the regenerating nerve microenvironment. To facilitate clinical adoption of the technology, we investigated ...photosealed autologous tissue in a rodent sciatic nerve transection and repair model. Rats underwent transection of the sciatic nerve with repair performed in three groups: standard microsurgical neurorrhaphy (SN) and photochemical sealing with a crosslinked human amnion (xHAM) or autologous vein. Functional recovery was assessed at four-week intervals using footprint analysis. Gastrocnemius muscle mass preservation, histology, and nerve histomorphometry were evaluated at 120 days. Nerves treated with a PTB-sealed autologous vein improved functional recovery at 120 days although the comparison between groups was not significantly different (SN: −58.4 +/− 10.9; XHAM: −57.9 +/− 8.7; Vein: −52.4 +/− 17.1). Good muscle mass preservation was observed in all groups, with no statistical differences between groups (SN: 69 +/− 7%; XHAM: 70 +/− 7%; Vein: 70 +/− 7%). Histomorphometry showed good axonal regeneration in all repair techniques. These results demonstrate that peripheral nerve repair using photosealed autologous veins produced regeneration at least equivalent to current gold-standard microsurgery. The use of autologous veins removes costs and foreign body concerns and would be readily available during surgery. This study illustrates a new repair method that could restore normal endoneurial homeostasis with minimal trauma following severe nerve injury.
Nerve xenografts harvested from transgenic α1,3-galactosyltransferase knockout (GalT-KO) pigs lack the epitope responsible for hyperacute rejection in pig-to-primate transplants. It is unknown ...whether these cold preserved nerve grafts support axonal regeneration in another species during and after immunosuppression. In this study, we compare outcomes between autografts and cold preserved xenografts in a rat sciatic model of nerve gap repair.
Fifty male Lewis rats had a 1 cm sciatic nerve defect repaired using either: autograft and suture (n=10); 1-week or 4-week cold preserved xenograft and suture (n=10 per group); 1-week or 4-week cold preserved xenograft and photochemical tissue bonding using a human amnion wrap (PTB/HAM) (n=10 per group). Rats with xenografts were given tacrolimus until 4 months post-operatively. At 4 and 7 months, rats were euthanized and nerve sections harvested. Monthly sciatic functional index (SFI) scores were calculated.
All groups showed increases in SFI scores by 4 and 7 months. The autograft suture group had the highest axon density at 4 and 7 months. The largest decrease in axon density from 4 to 7 months was in the 1-week cold preserved PTB/HAM group. The only significant difference between group SFI scores occurred at 5 months, when both 1-week cold preserved groups had significantly lower scores than the 4-week cold preserved suture group.
Our results in the rat sciatic model suggest that GalT-KO nerve xenografts may be viable alternatives to autografts and demonstrate the need for further studies of long-gap repair and comparison with acellular nerve allografts.
This proof-of-concept study in the rat sciatic model demonstrates that cold preserved GalT-KO porcine xenografts support axonal regeneration, as well as axonal viability following immunosuppression withdrawal. These results further suggest a role for both cold preservation and photochemical tissue bonding in modulating the immunological response at the nerve repair site.
Photochemical tissue bonding (PTB) is a technique for peripheral nerve repair in which a collagenous membrane is bonded around approximated nerve ends. Studies using PTB with cryopreserved human ...amnion have shown promising results in a rat sciatic nerve transection model including a more rapid and complete return of function, larger axon size, and thicker myelination than suture repair. Commercial collagen membranes, such as dehydrated amnion allograft, are readily available, offer ease of storage, and have no risk of disease transmission or tissue rejection. However, the biomechanical properties of these membranes using PTB are currently unknown in comparison to PTB of cryopreserved human amnion and suture neurorrhaphy.
Rat sciatic nerves (
= 10 per group) were transected and repaired using either suture neurorrhaphy or PTB with one of the following membranes: cryopreserved human amnion, monolayer human amnion allograft (crosslinked and noncrosslinked), trilayer human amnion/chorion allograft (crosslinked and noncrosslinked), or swine submucosa. Repaired nerves were subjected to mechanical testing.
During ultimate stress testing, the repair groups that withstood the greatest strain increases were suture neurorrhaphy (69 ± 14%), PTB with crosslinked trilayer amnion (52 ± 10%), and PTB with cryopreserved human amnion (46 ± 20%), although the differences between these groups were not statistically significant. Neurorrhaphy repairs had a maximum load (0.98 ± 0.30 N) significantly greater than all other repair groups except for noncrosslinked trilayer amnion (0.51 ± 0.27 N). During fatigue testing, all samples repaired with suture, or PTBs with either crosslinked or noncrosslinked trilayer amnion were able to withstand strain increases of at least 50%.
PTB repairs with commercial noncrosslinked amnion allograft membranes can withstand physiological strain and have comparable performance to repairs with human amnion, which has demonstrated efficacy in vivo. These results indicate the need for further testing of these membranes using in vivo animal model repairs.
Background: Lipedema is the progressive symmetrical deposition of subcutaneous fat and fluid in the lower body, ordinarily sparing the trunk, upper limbs, face, and neck. It may follow an autosomal ...dominant inheritance pattern. The gold standard treatment for lipedema is complete decongestive therapy, consisting of manual lymphatic drainage and compression garments. This scoping review assessed the existing literature on the effectiveness of liposuction as an alternative treatment for lipedema. Methods: A scoping review of electronically available literature within PubMed, Scopus, and Cochrane focused on liposuction as a treatment for lipedema considering the following inclusion criteria: human studies, case series of 10 or more, controlled trials, randomized controlled trials, patient-reported outcome measurement studies, survey analyses, descriptive studies, retrospective analyses, recurrence included, follow-up of 6 months or more, age 18 years or older, and treatment modality being liposuction. Results: Thirteen studies were selected. Nine studies reported decreased compression therapy use among patients following liposuction. No studies reported a long-term increase in compression therapy following liposuction. Studies found self-reported improvements in pain, mobility, bruising, and overall quality of life for patients following liposuction, many of whom had previously been on compressive therapy. Studies reported low rates of serious adverse events following liposuction, including deep vein thrombosis, pulmonary embolism, and infection. Conclusions: These results suggest that liposuction can be a viable treatment alternative to compression therapy for lipedema in patients whose compression therapy has not been helpful. However, there is not enough evidence to say whether liposuction is as effective as compression for patients first presenting with lipedema.
