Effects of hyperbaric oxygen therapy on caustic esophageal injury in rats

Update on hyperbaric oxygen therapy in burn treatment

Hyperbaric oxygen therapy (HBOT) has been shown to improve tissue hypoxia, neovascularization and ischemia reperfusion injury and reduce pathologic inflammation in various clinical settings and was proposed to be a game changer in treatment of burns. Improved and faster wound healing as well as a reduction of morbidity and mortality after thermal and concomitant carbon monoxide poisoning are expected. In defiance of the observed benefits for burn wounds and carbon monoxide poisoning in animal models and few randomized controlled trials there is an ongoing controversy regarding its use, indications and cost effectiveness. Furthermore, the use of HBOT, its indications and the evidence behind its efficiency are still widely unknown to most physicians involved in the treatment of burn patients. Therefore, a review of the up to date evidence-based literature was performed with a focus on available data of HBOT in burn care, to elaborate its use in acute thermal injury and carbon monoxide intoxication. Although beneficial effects of HBOT seem very likely insufficient evidence to support or disprove the routine use of HBOT in the treatment of burn care was found. Although difficult to carry out because of the high interindividual variability of burns and chronic wounds, the need for larger high-quality prospective randomized double-blinded controlled multicenter trials are necessary to be able to evaluate useful applications, expense and cost-efficiency of HBOT for burn care.

Esophageal Stricture Following Radiation, Concurrent Immunochemotherapy, Treated With Hyperbaric Oxygen and Dilation

Low-dose palliative radiation may offer symptomatic relief in patients with spinal metastases from primary renal cell cancer and is unlikely to result in radiation injury. Patients with advanced malignancy requiring palliative radiation are often also receiving chemotherapy. Synergistic adverse effects resulting from combined palliative radiation and novel antiprogrammed cell death-1 (anti-PD 1) and/or multityrosine kinase inhibitors are rare.

We report about a 60-year-old woman with metastatic clear-cell renal cancer, status post-left nephrectomy, with debilitating mid-back pain from metastatic tumor burden and foraminal nerve compression. Her chemotherapeutic regimen was repeatedly altered because of progression of disease until she was maintained on the anti-PD 1 checkpoint inhibitor, nivolumab. She received palliative radiation to her thoracic spine over a 2-week period, and nivolumab was then switched to cabozantinib midway through a course of palliative radiation. The patient rapidly developed severe esophagitis, progressing to esophageal stricture, and required placement of a percutaneous endoscopic gastrostomy tube. She was successfully treated with serial esophageal dilation and hyperbaric oxygen treatments to diminish inflammation and improve tissue vascularity. Concurrent use of anti-PD 1 and/or multityrosine kinase drugs may accelerate development of radiation injury regardless of radiation dosage. Radiation-induced esophageal stricture was managed successfully in this patient with serial esophageal dilation and adjuvant hyperbaric oxygen.

Effect of polaprezinc on experimental corrosive esophageal burns in rats

Unconsciously caustic ingestion is one of the most common causes of serious esophageal strictures in children. The aim of this study is to determine the efficiency of polaprezinc in preventing stricture formation after corrosive esophageal burns (CEB); this was the first time it has been used to treat experimental CEB in rats. Twenty-four rats were divided into four groups, three of which received CEB by the instillation of 1 mL of 10% NaOH solution into their isolated esophageal segments for three minutes. Group C (control) was uninjured and untreated. Group B (esophageal burn) received CEB but were left untreated. Groups PT1 and PT2 had CEB and received 100 mg/kg/day and 200 mg/kg/day, respectively, of intraperitoneal polaprezinc treatment (PT) for the first two weeks, then oral PT for another two weeks. We assessed the treatment's efficiency of the treatment after the fourth week by evaluating the stenosis index (SI) and the histopathological damage score, determining tissue hydroxyproline content (HP), and measuring the weight of the rats before and after the experiment. Mean SI was statistically lower in the groups PT1 and PT2 when compared with Group B (p = 0.006, 0.004, respectively). HP levels were highest in Group B, but it was insignificant (P> 0.05). In terms of histopathological damage score, treatment groups demonstrated less collagen deposition, mucosal, and submucosal damage than both Group B (p = 0.01) and Group C (p = 0.02). Group PT1 and Group PT2 (P> 0.05) showed similar results, indicating the treatment's effectiveness was independent of dosage. Outside of Group C, weight gain was detected only in Group PT2, though it was statistically insignificant. In Group PT1, weight loss was lower than in Group B. Polaprezinc, with its antifibrotic, antioxidant, anti-inflammatory, wound-healing and antiapoptotic effects, was efficient in reducing stricture formation by decreasing HP levels and histopathologic damage, preventing stenosis, and weight gain in higher dosages in the treatment group.

Effectiveness of thymoquinone, zeolite, and platelet-rich plasma in model of corrosive oesophagitis induced in rats

Purpose

The effectiveness of platelet-rich plasma (PRP), thymoquinone, and zeolite in corrosive esophageal burns was investigated in a rat model.

Methods

Four groups were comprised as containing 10 rats in each group. For group I, oesophagitis was induced and no other procedure was performed (control group). For group II, oesophagitis was induced and thymoquinone was administered for 1 week via oral gavage once a day (thymoquinone group). For group III, oesophagitis was induced for 1 week via oral gavage once a day (PRP group). For group IV, oesophagitis was induced and zeolite was administered for 1 week via oral gavage once a day (zeolite group). On the 10th day, the rats were sacrificed under anaesthesia and venous blood sampling was performed from the vena portae. The oesophaguses were totally excised. Biochemically, interleukin (IL)-1B, IL-6, TNF-α, and MCP-1 were examined from venous blood. Inflammation score was evaluated histopathologically in oesophageal tissue that was collected.

Results

There was a statistically significant difference among groups in terms of IL-1, IL-6, MCP levels, compared to the control group; median IL-1, IL-6, MCP levels of thymoquinone, PRP, and zeolite groups were statistically significantly lower. There was a statistically significant difference among groups in terms of inflammation scores, compared to group I; median inflammation scores of groups II, III and IV were statistically significantly lower thymoquinone.

Conclusion

PRP, and zeolite exhibited positive effect on recovery in oesophagitis by reducing inflammation in the involved segment.

Effects of tenoxicam in experimental corrosive esophagitis model

Esophageal stricture, one of the important complications of corrosive esophagus, develops following edema and granulation tissue that forms during and after the inflammatory reactions. Tenoxicam, a non-steroid anti-inflammatory drug with a long half-life, prevents various leukocyte functions including phagocyte and histamine secretion by inhibiting prostaglandin synthesis and removes various oxygen radicals in the region of inflammation. We designed this as a histopathological study using tenoxicam in rats for which we created a corrosive esophagus model. After necessary authorizations were obtained, the study was performed in Çanakkale 18 Mart University experimental animal laboratory. Twenty-four Wistar albino rats, weighing 220-240 g, were used for the experiment. Experimental animals were randomized into three groups: tenoxicam group (group T, n:8), control group (group C, n:8), and sham group (group S, n:8). Tenoxicam 0.5 mg/kg/day was administered to animals in group T, where esophageal burn was developed experimentally, 5 mg/kg 0.9% NaCL was administered i.p. to rats in group C for 15 days, once in 24 hours. No procedure was applied to rats in group S. After 15 days, all animals were sacrificed under general anesthesia and their esophagi were extracted. As a result of histopathological evaluation, inflammation and fibroblast proliferation was not observed in rats in the sham group (group S). Intense inflammation was observed in six rats (6+/2-) in the control group, and fibroblast proliferation was observed as 5+/3-. And in treatment groups, inflammation was evaluated as 3+/5-, and fibroblast proliferation as 3+/5-. In our study, histopathologic damage score was higher in the control group (P < 0.005). We deduce that tenoxicam can be useful in the treatment of caustic esophageal injuries in the acute phase, but think that these drugs require further researches and clinical studies before routine clinical use.

Efficacy of keratinocyte growth factor (palifermin) for the treatment of caustic esophageal burns

Current treatment strategies against the development of corrosive esophageal strictures remain unsatisfactory. Thus, the aim of the present study was to investigate the efficacy of keratinocyte growth factor, in the form of palifermin, for the prevention of stricture development following esophageal caustic injuries in a rat model. A total of 32 female Wistar albino rats were divided into four groups, which included the control (C), burn (B), steroid (S) and steroid plus palifermin (S/P) groups. An experimental corrosive esophageal burn model was established in the B, S and S/P groups. Weight gain was recorded and histopathological evaluation was performed for each group. Weight gain in the S and B groups was compared with the control group and statistically significant differences were observed. In addition, statistically significant differences in weight gain were observed between the S/P group and the B group. Histopathologically, statistically significant differences were identified with regard to submucosal collagen deposition, muscularis mucosa and tunica muscularis damage when comparing the B group with the C group. In addition, statistically significant differences were observed when comparing the S and S/P groups with the B group. Furthermore, significant submucosal collagen deposition and tunica muscularis damage were observed in the S group when compared with the S/P group. The stenosis indexes in the C and S groups were significantly lower compared with the B group. In addition, the stenosis index in the S/P group was significantly lower compared with the S group. To the best of our knowledge, the present study is the first to investigate the effect of palifermin on corrosive esophageal burns. The addition of palifermin to the corrosive esophageal burn standard treatment regimen was found to reduce the degree of fibrosis and ameliorate histopathological damage in an experimental model of corrosive esophagitis in rats.

Preliminary study of efficacy of hyaluronic acid on caustic esophageal burns in an experimental rat model

BACKGROUND

The aim of this study was to investigate the effectiveness of hyaluronic acid on the prevention of esophageal damage and stricture formation after experimental caustic (alkaline) esophageal injury in rats.

MATERIALS AND METHODS

Twenty-one Wistar albino rats were randomly divided into three groups. A caustic esophageal burn was created following the Gehanno model: Group l (n=7) underwent operation, but no injury; Group 2 (n=7) was injured and left untreated; and Group 3 (n=7) was injured and treated with hyaluronic acid, first topically and then orally by gavage (2×0.3mL; 12.5mg/mL for 7days). The caustic esophageal burn was created by instilling 25% NaOH into the distal esophagus. All rats were euthanized on day 22 for evaluation. The efficacy of hyaluronic acid treatment was assessed histopathologically and biochemically via blood determination of the total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and sulfhydryl group (SH) and lipid hydroperoxidase (LOOH) levels. Statistical analyses were performed.

RESULTS

Weight gain was significantly lower in Group 2 than in the other two groups (P<0.05). The mean stenosis index, histopathologic damage score, TAS, TOS, OSI, and SH and LOOH levels were higher in Group 2 than in the other two groups. The mean stenosis index, inflammation, TAS, SH and OSI in Group 2 were significantly different than those in the other two groups (P<0.05).

CONCLUSION

Hyaluronic acid treatment is effective in treating damage and preventing strictures after caustic esophageal burn in rats.

Beneficial effects of Ankaferd Blood Stopper on caustic esophageal injuries: an experimental model

Ankaferd Blood Stopper (ABS) is an herbal extract that enhances mucosal healing. The aim of this study was to investigate the efficacy of ABS on the healing of the esophagus and prevention of stricture development after esophageal caustic injuries in rats. The study included 50 rats. Rats were divided into five groups: group 1 (no injury, sham surgery), group 2 (injury + no ABS + study after 2 weeks of injury), group 3 (injury + ABS + study after 2 weeks of injury), group 4 (injury + no ABS + study after 4 weeks of injury), and group 5 (injury + ABS + study after 4 weeks of injury). Standard esophageal burn injury was created by applying 50% NaOH solution to distal esophagus of about 1.5 cm. To rats in the sham group, isotonic solution was given instead of NaOH. ABS (2 mL/day) was given via oral route to group 3 and 5 rats. Fourteen days (group 2 and 3) and 28 days (group 4 and 5) later, all the live rats were killed. The distal esophageal segments of all rats were removed and divided into two equal parts for biochemical and histopathological examination. Mortality rate, weight changes, inflammation, stenosis index (SI), and biochemical measurements were evaluated. The SI was found as 0.31 ± 0.03 in group 1, 0.533 ± 0.240 in group 2, 0.568 ± 0.371 in group 3, 0.523 ± 0.164 in group 4, and 0.28 ± 0.03 in group 5. The SI and inflammation in ABS-treatment group 5 was significantly lower than that in non-treatment group 4 (P= 0.005). There were no significant differences between inflammation and SI among other groups. The mortality rate was 14.2% in group 1, 37.5% in untreated group 2, 14.2% in ABS-treated group 3, 80% in untreated group 4, and 33.3% in ABS-treated group 5. The mortality rate in group 4 was significantly higher than other groups (P= 0.025). Decrease rates in mean body weights of the groups were as follows: group 1, 1%; group 2, 15%; group 3, 14%; group 4, 46%; and group 5, 15%. Biochemical tests other than albumin and creatinine were comparable among the groups. Treatment with ABS prevents inflammation, scar formation, weight loss, and mortality in esophageal caustic injuries. Additional studies to evaluate the clinical benefits of ABS in esophageal caustic injury are recommended.

Development of a model of benign esophageal stricture in rats: the optimal concentration of sodium hydroxide for stricture formation

PURPOSE

To investigate the optimal concentration of sodium hydroxide (NaOH) on esophageal stricture formation in rats to establish an animal model of benign esophageal stricture (BES).

METHODS

Corrosive esophageal burn was produced by internal application of different concentrations of NaOH to the distal esophagus in rats. As much as 66 male rats were randomly divided into eight groups: Group A (control, n = 6), Group B (sham-operated group, n = 6), Group C (5% NaOH, n = 8), Group D (10% NaOH, n = 8), Group E (20% NaOH, n = 8), Group F (30% NaOH, n = 10), Group G (40% NaOH, n = 14), and Group H (50% NaOH, n = 6). Surviving rats were killed at 28 days. The survival rate, body weight gain, symptoms, and histopathological changes were assessed.

RESULTS

The mortality rate was high in Groups G and H (73 and 67%). The prevalence of symptoms of BES was 43% in Groups D and E, 50% in Group F, 75% in Group G, and 100% in Group H. Statistically significant stricture formation of the esophagus was observed in Groups F and G. The degree of tissue damage was significantly higher in Groups E, F, and G.

CONCLUSION

A high concentration of NaOH of 30% was required to establish a survivable BES model in rats.

Protective effects of ibuprofen against caustic esophageal burn injury in rats

PURPOSE

The aim of this study was to investigate the efficacy of ibuprofen on the healing of esophagus and the prevention of stricture development after esophageal caustic injuries in rats.

MATERIALS AND METHODS

Rats were divided into three groups as: group 1(sham), group 2(esophageal burn injury), group 3(injury + ibuprofen). In groups 2 and 3, a standard esophageal burn injury was created by applying 10% NaOH solution to distal esophagus of about 3 cm. To rats in the sham group, isotonic solution was given instead of NaOH. Ibuprofen (90 mg/kg/day) was given via oral route to group 3 rats. Normal saline as placebo was given via the same route to rats in groups 1 and 2. 28 days later, all the live rats were killed. The distal esophageal segments of all rats were removed and divided into two equal parts for biochemical and histopathologic examination. In the tissue samples, biochemically hydroxyproline and histopathologically collagen content and stenosis indices were evaluated for efficacy of treatment.

RESULTS

The hydroxyproline level (microg/mg wet tissue) in the groups was 1.54 +/- 0.08, 4.82 +/- 0.60, and 3.28 +/- 0.27, respectively. The hydroxyproline level increased significantly in group 2 compared with group 1 (P < 0.01). Although the hydroxyproline level was significantly increased in group 3 compared with group 1, it decreased significantly in group 3 compared with group 2 (P < 0.05) by treatment of ibuprofen. In group 3, the collagen content score (1.50 +/- 0.26) was significantly lower than in group 2 (2.62 +/- 0.37) (P < 0.05). The stenosis index was found as 0.37 +/- 0.02 in group 1, 0.84 +/- 0.02 in group 2, and 0.67 +/- 0.03 in group 3. The stenosis index in group 2 was significantly higher than group 1 and group 3 (P < 0.01). Although the stenosis index was significantly higher than in group 1, a significant decrease in stenosis index was found in group 3 compared with group 2, by ibuprofen treatment (P < 0.01).

CONCLUSION

Based on these results, we concluded that the treatment with ibuprofen in acute phase esophageal burn injury has beneficial effects on healing of esophagus and may decrease the stricture formation. For these reasons, ibuprofen may effectively be used in the acute phase treatment of caustic esophagus injury and after esophageal dilatation procedures.

The efficacy of ozone therapy in experimental caustic esophageal burn

INTRODUCTION

Ozone has been proposed as an antioxidant enzyme activator, immunomodulator and cellular metabolic activator. This study was designed to investigate the efficacy of ozone therapy in the prevention of esophageal damage and stricture formation developed after esophageal caustic injuries in the rat.

MATERIALS AND METHODS

Forty-five rats were allocated into three groups; sham-operated, un-treatment and treatment groups. Caustic esophageal burn was created by instilling 15% NaOH in the distal esophagus. The rats were left untreated or treated with 1 mg/kg/day ozone intraperitoneally. All rats were sacrificed at 28 days. Efficacy of the treatment was assessed by measuring the stenosis index (SI) and histopathologic damage score, and biochemically by determining tissue hydroxyproline content (HP), superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA) and protein carbonyl content (PCC) in esophageal homogenates.

RESULTS

Whereas seven (47%) rats died in the un-treatment group, all rats in the sham-operated and the treatment group survived during the study. SI, the histopathologic damage score, was significantly lower in the ozone-therapy group than the un-treatment group. HP levels were significantly higher in the un-treatment group than the group treated with ozone. Caustic esophageal burn increased MDA and PCC levels and also decreased SOD and GPx enzyme activities. In contrast, ozone therapy decreased the elevated MDA and PCC levels and also increased the reduced SOD and GPx enzyme activities.

CONCLUSION

Ozone has a preventive effect in the development of fibrosis by decreasing tissue damage and increasing the antioxidant enzyme activity in an experimental model of corrosive esophageal injury.