Pentoxifylline Inhibits Epidural Fibrosis in Post-Laminectomy Rats

Effect of Ozone Therapy on Epidural Fibrosis in Rats

OBJECTIVE

To demonstrate the effect of medical ozone therapy on the development of epidural fibrosis.

METHODS

A total of 25 Sprague-Dawley male rats were randomly divided into 3 groups: a control group (L3-L4 laminectomy only), a systemic ozone therapy (SOT) group (L3-L4 laminectomy only + intraperitoneal 15 mL [30 μg/mL] ozone), and a local ozone therapy (LOT) group (L3-L4 laminectomy only + subcutaneous 15 mL [30 μg/mL] ozone). Ozone therapy was administered 4 times on a 3-day interval during the wound-healing process, with the first dose immediately administered after surgery. The effects of ozone therapy on vascular endothelial growth factor, inflammation, and epidural fibrosis between groups were evaluated.

RESULTS

Staining with vascular endothelial growth factor was significantly less in the group that received SOT compared with the control group (P = 0.021). When the groups were compared in terms of inflammation, it was found that inflammation was less common in the SOT and LOT groups compared with the control group (SOT vs. control: P = 0.004 and LOT vs. control: P = 0.024), whereas inflammation was found to be significantly less in the SOT group compared with the LOT group (P = 0.008). In the histopathologic evaluation of epidural fibrosis, there was no significant difference between the SOT and LOT groups but less epidural fibrosis was observed in both groups compared to the control group (LOT vs. control: P = 0.037; SOT vs. control: P = 0.018).

CONCLUSIONS

Medical ozone therapy may be an alternative method that can be used effectively and safely in the prevention of epidural fibrosis after laminectomy.

Efficacy of Surgical Excision and Adjuvant High-dose Rate Brachytherapy in Treatment of Keloid: Our Experience

Background

Keloids are dermal tumors that are due to increased production of collagen caused by abnormal and prolonged wound healing. The incidence of recurrence is extremely high if only conservative measures are used. This study was conducted to evaluate the feasibility and efficacy surgery and high dose rate brachytherapy as an adjuvant therapy for treatment of keloids.

Materials and Methods

50 patients with clinically diagnosed 71 keloids were treated with excision of keloid and post-operative high-dose rate brachytherapy were studied. Complete excision of the keloid till the healthy skin margin was excised. The wound were closed in 2 layers. Subcutaneous tissue closed using absorbable suture, over which a 6F flexible polyethylene tube was placed. High dose rate cobalt-60 brachytherapy was administered. Total of 15 Gy in divided dose, 5 Gy in 3 fractions were administered.

Results

50 patients with 71 keloids were studied. Out of the 50 patients, 12 were male (24%) and 38 were females (76%). Age of the patients ranged between 14 and 71 years. Recurrence rate was 2% with 2 keloids recurring at 5 months interval. 4 patients scored the results as unacceptable, remaining 45 patients rated their results as excellent during their follow up at 10 days, 3 months and 6 months.

Conclusion

Treatment of keloids in the plastic surgeon's practice even today is still challenging. Many therapies have been described, but recurrence rate is high with mono-therapy. Combination therapy especially surgical excision with postoperative radiotherapy is best in preventing recurrence.

The histopathological effects of reabsorbable polyethylene glycol hydrogel (Coseal) on epidural fibrosis in an experimental postlaminectomy model in rats

Background/aim

To investigate the histopathological effects of reabsorbable polyethylene glycol hydrogel (RPGH, Coseal) on epidural fibrosis (EF) following laminectomy in rats.

Materials and methods

A total of 24 rats were equally divided into three groups. In the first group, no treatment was applied after laminectomy (control group, Group 1). In the second group, hemostasis was achieved after laminectomy, and 2 mm absorbable gelatin sponge soaked in saline was placed over the epidural space and the wound was closed (Group 2). In the third group, hemostasis was achieved following laminectomy, and 0.5 mL RPGH (Coseal, Group 3) was squeezed over the dura mater, and the wound was closed. A histopathological examination was undertaken to evaluate arachnoidal invasion and EF.

Results

The results of EF in the Group 2 and Group 3 were significantly lower compared to the Group 1 (p = 0.023 and p = 0.002, respectively). No statistically significant difference was found between the Group 2 and Group 3 in terms of EF (p = 0.957). There was also no statistically significant difference between the mean arachnoidal invasion of the three groups (p > 0.171). However, the rate of arachnoidal invasion was the lowest in the Group 3.

Conclusion

Intraoperative Coseal, a polyethylene glycol polymer, tends to reduce the risk of epidural fibrosis, although this is not statistically significant.

Impact of radial extracorporeal shock wave therapy in post-laminectomy epidural fibrosis in a rat model

Objectives

This study aims to investigate the effect of radial extracorporeal shock wave therapy (rESWT) treatment in the prevention of epidural fibrosis after laminectomy in rats.

Materials and methods

Eighteen 16-month-old male Sprague-Dawley rats weighing 300 g were used in this experimental study between November 2019 and February 2020. The rats were randomly divided into two groups as the control group (L3-L4 total laminectomy without any treatment) and the study group (L3-L4 total laminectomy plus rESWT). The rats were sacrificed at the postoperative sixth week and the lumbar spine was excised en bloc, fixed, and decalcified. Sections were stained with hematoxylin-eosin to evaluate epidural fibrosis, acute inflammation, chronic inflammation, and vascular proliferation.

Results

The median value and standard deviations were obtained based on histological examinations. Accordingly, epidural fibrosis decreased significantly in the study group compared to the control group. There was no statistically significant difference between the groups in terms of acute and chronic inflammation response and vascular proliferation.

Conclusion

The rESWT application immediately after surgery is effective in preventing epidural fibrosis after laminectomy in rats.

A Novel Radiotherapy Approach for Keloids with Intrabeam

Background

Keloids are hard nodules or plaques formed by excessive proliferation of connective tissue. Radiotherapy, widely used in various benign and malignant skin diseases, is an effective treatment for keloids. This work evaluates Intrabeam photon radiotherapy in the management of keloids.

Methods

Fourteen patients who have undergone Intrabeam radiotherapy for a total of 15 sites of keloids were followed up. Twelve cases were first onset and the other two had recurrent diseases. Thirteen patients underwent surgical resection of keloids before radiotherapy. One relapsing patient received only 2 rounds of radiation therapy as she could not be reoperated. Radiotherapy was divided into 2 sessions on days 0 and 3 after surgery. The dose was 4 or 5 Gy each time for 3 min 14 s to 12 min 1 s. In addition, we compared our data to the recurrence of keloids in fourteen patients who had previously been exposed to electron beam using conventional accelerators.

Results

We analyzed the treatment for adverse reactions and recurrence. In the Intrabeam group, one patient developed superficial skin ulcers a month after treatment. No one experienced wound rupture, bleeding, infection, skin contractures, or obvious hyperpigmentation. None of the fourteen cases showed any recurrence so far after on median 22.5 months of follow-up. Five patients in the electron beam group relapsed 3 to 10 months after treatment.

Conclusion

Here, Intrabeam photon radiotherapy was shown to be an effective treatment for keloid scars and it is therefore recommended for management of this disease.

Prospective application of stem cells to prevent post-operative skeletal fibrosis

Post-operative skeletal fibrosis is considered one of the major complications causing dysfunction of the skeletal system and compromising the outcomes of clinical treatment. Limited success has been achieved using current therapies; more effective therapies to reduce post-operative skeletal fibrosis are needed. Stem cells possess the ability to repair and regenerate damaged tissue. Numerous studies show that stem cells serve as a promising therapeutic approach for fibrotic diseases in tissues other than the skeletal system by inhibiting the inflammatory response and secreting favorable cytokines through activating specific signaling pathways, acting as so-called medicinal signaling cells. In this review, current therapies are summarized for post-operative skeletal fibrosis. Given that stem cells are used as a promising therapeutic approach for fibrotic diseases, little effort has been undertaken to use stem cells to prevent post-operative skeletal fibrosis. This review aims at providing useful information for the potential application of stem cells in preventing post-operative skeletal fibrosis in the near future. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1236-1245, 2019.

Artesunate inhibits fibroblasts proliferation and reduces surgery-induced epidural fibrosis via the autophagy-mediated p53/p21waf1/cip1 pathway

Fibroblast proliferation is considered to be a major cause in the process of epidural fibrosis formation. Autophagy is a tightly-regulated catabolic process in charge of degrading intracellular components. Although autophagy has been associated with fibrosis of different tissues, the effect of autophagy on epidural fibrosis is still unknown. The aim of this study was to investigate the function and mechanism of autophagy induced by Artesunate (ART), a classical antimalarial agent extracted from the Chinese medicinal herb. In vitro, the effect of ART on inducing fibroblast autophagy was evaluated via LC3 immunofluorescent staining, Transmission Electron Microscopy (TEM) and western blotting analysis. Moreover, the effect of ART on inhibiting fibroblast proliferation was investigated by CCK-8 assay, EdU incorporation assay, flow cytometry and western blotting analysis. Results indicated that ART could induce autophagy and inhibit proliferation in fibroblasts. The inhibitory effect of ART on fibroblast proliferation was associated with the upregulation of p53 and p21^waf1/cip1 proteins. Intriguingly, 3-MA, a classical autophagy inhibitor, attenuated ART-induced p53/p21^waf1/cip1 pathway activation and fibroblast proliferation inhibition. In vivo, the effect of ART on reducing epidural fibrosis was detected by histological macroscopic assessment, hydroxyproline content analysis, histological and immunohistochemical staining. The results revealed that ART had significant suppressive effects on epidural fibrosis following laminectomy in rats. In conclusion, this research demonstrated that ART could inhibit fibroblast proliferation and reduce epidural fibrosis formation after laminectomy, and the potential mechanism might through autophagy cascade-mediated p53/p21^waf1/cip1 pathway. It might provide a novel reagent for reducing epidural fibrosis after spinal laminectomy surgery.

Repurposing Pentoxifylline for the Treatment of Fibrosis: An Overview

Fibrosis is a potentially debilitating disease with high morbidity rates. It is estimated that half of all deaths that occur in the USA are attributed to fibrotic disorders. Fibrotic disorders are characterized primarily by disruption in the extracellular matrix deposition and breakdown equilibrium, leading to the accumulation of excessive amounts of extracellular matrix. Given the potentially high prevalence of fibrosis and the paucity of agents currently available for the treatment of this disease, there is an urgent need for the identification of drugs that can be utilized to treat the disease. Pentoxifylline is a methylxanthine derivative that is currently approved for the treatment of vascular diseases, in particular, claudication. Pentoxifylline has three main properties: improving the rheological properties of blood, anti-inflammatory, and antioxidative. Recently, the effectiveness of pentoxifylline in the treatment of fibrosis via attenuating and reversing fibrotic lesions has been demonstrated in several clinical trials and animal studies. As a result of the limited availability of antifibrotic agents in the long-term treatment of fibrosis that can attenuate and even reverse fibrotic lesions effectively, it would be of particular importance to consider the potential clinical utility of pentoxifylline in the treatment of fibrosis. Thus, this paper discusses the evolving roles of pentoxifylline in the treatment of different types of fibrosis.

Salvianolic acid B reduced the formation of epidural fibrosis in an experimental rat model

Background

Salvianolic acid B (Sal B) was newly reported to be able to attenuate fibrosis in the animal model. The aim of the present study was to investigate the effect of the intragastric application of Sal B on the prevention of epidural fibrosis (EF).

Methods

Forty healthy adult male Wistar rats were divided into four treatment groups (n = 10 per group): (1) 10 mg/kg Sal B, (2) 30 mg/kg Sal B, (3) 50 mg/kg Sal B and (4) Saline (vehicle treatment, control group). All animals underwent a laminectomy at the lumbar 1–2 (L 1–2) level. After intragastric treatment, all rats were sacrificed at post-operative week 8. The extent of the epidural scar, the regeneration of the vasculature and the expression levels of vascular endothelial growth factor (VEGF) were analysed.

Results

The animals’ recovery was uneventful during the experimental period. The extent of the epidural scar, the regeneration of the vasculature and the expression levels of VEGF suggested better outcomes in the Sal B-treated groups. Sal B exerted the ability to prevent the formation of an epidural scar and vascularization at the laminectomy sites. The effects of Sal B were dose-dependent, with the 50 mg/kg Sal B group showing the best outcomes compared with the other groups.

Conclusions

Post-operative intragastric application of Sal B can prevent the formation of epidural scarring. Sal B exerted these effects in a dose-dependent manner, and 50 mg/kg dose was shown to be the best effect in the present study. The results of this study reveal that Sal B could be a potential therapy for EF and valuable for further research.