Mitomycin C decreases the rate of stricture formation in caustic esophageal burns in rats

Effect of castor oil on esophageal stricture in rats and expression of ST-2, neopterin proteins in corrosive burn model

Corrosive esophageal burn (CEB) is a disease with high mortality and morbidity rates. The aim of this study was to determine the efficacy of castor oil, in preventing stricture development at the experimental CEB model. In addition to studying standard histopathological damage data, neopterin, IL-33, and ST-2 proteins were also studied for the first time. Fifty Wistar-Albino rats were divided into randomized 5 groups. [Sham group (G1) (n:10), Control group (G2) (n:10), Early Stage Topical Application group (G3)(n:10), Late Stage Topical Application group (G4) (n:10), Oral Application group (G5) (n:10)]. Weight measurement, esophageal length, histopathological damage score (HDS) and total stenosis score (TSS), tissue caspase-3 and VEGF staining, tissue hydroxyproline (HYP), blood TNF-alpha, IL-6, IL-33, Neopterin, and ST-2 levels were measured. In the castor oil application groups, weight gain was observed, the acute phase reaction decreased, submucosal/tunica muscularis fibrosis (TMF) and muscularis mucosal damage (MMD) were reduced, and TSS and HDS decreased. While no significant difference was detected in the ST-2 protein, which was used for the first time in this study model, a significant increase in neopterin protein was observed in the application groups. Results indicate the nutritional contribution of castor oil, as well as its tissue healing and esophageal stricture-preventing efficacy at histopathological and immune-histochemical levels.

A Novel Rat Model to Simulate the Benign Esophageal Stricture Induced by Endoscopic Submucosal Dissection

OBJECTIVE

This study aimed to establish a rat model that simulates benign esophageal strictures induced by endoscopic submucosal dissection (ESD).

MATERIALS AND METHODS

Sixteen male Sprague-Dawley rats were randomly divided into mucosal resection (n = 8) and sham-operated groups (n = 8). The rats in the mucosal resection group underwent a 5-mm three-fourths mucosal resection by way of a 3-mm incision in the distal esophagus under direct visualization via laparotomy. Rats in the sham-operated group underwent a 3-mm incision of the muscularis propria layer in the distal esophagus via laparotomy without mucosal resection. Dysphagia score, weight gain, mucosal constriction rate, and histology were evaluated 2 weeks after surgery.

RESULTS

Technical success was achieved in all the animals. One rat in the mucosal resection group died of infection, and no other complications were observed. Weight gain (P < 0.001) and luminal diameter derived from the esophagograms (P < 0.001) were significantly lower in the mucosal resection group than those in the sham-operated group. Dysphagia score (P < 0.001) and mucosal constriction rate (P < 0.001) were significantly higher in the mucosal resection group than those in the sham-operated group. The inflammation grade (P = 0.002), damage to the muscularis propria (P < 0.001), number of nascent microvessels (P = 0.006), and degree of α-SMA positive deposition (P = 0.006) were significantly higher in the mucosal resection group.

CONCLUSION

A rat model of benign esophageal stricture induced by ESD was successfully and safely established by mucosal resection.

Infigratinib, a Selective Fibroblast Growth Factor Receptor Inhibitor, Suppresses Stent-Induced Tissue Hyperplasia in a Rat Esophageal Model

PURPOSE

Stent-induced tissue hyperplasia remains a challenge for the application of self-expanding metal stents in the management of esophageal stricture. This study aimed to evaluate the efficacy of infigratinib, which is a selective fibroblast growth factor receptor inhibitor, in the prevention of stent-induced tissue hyperplasia in a rat esophageal model.

METHODS

Twenty-four male Sprague-Dawley rats underwent esophageal stent placement and were randomized to receive 1 ml of vehicle, 5 mg/kg infigratinib in 1 ml of vehicle, or 10 mg/kg infigratinib in 1 ml of vehicle via naso-gastric tube once daily for 28 days. Follow-up fluoroscopy was performed on postoperative day 28, and the stented esophageal tissues were harvested for histological and immunofluorescence examinations.

RESULTS

All rats survived until euthanasia on postoperative day 28 without procedure-related adverse events. The incidence of stent migration was 12.5%, 12.5% and 25% in the control group, the 5 mg/kg infigratinib group and, the 10 mg/kg infigratinib group, respectively. The percentage of granulation tissue area, the submucosal fibrosis thickness, the number of epithelial layers, the degree of inflammatory cell infiltration, the degree of collagen deposition, the number of fibroblast growth factor receptor 1 (FGFR1)-expressing myofibroblasts, and the number of proliferating myofibroblasts were all significantly lower in both infigratinib groups than in the control group (P < 0.05) but were not significantly different between the two infigratinib groups (P > 0.05).

CONCLUSIONS

Infigratinib significantly suppresses stent-induced tissue hyperplasia by inhibiting FGFR1-mediated myofibroblast proliferation and profibrotic activities in a rat esophageal model.

The effects of hesperidin on stricture formation in corrosive esophageal burns: an experimental study

AIM/BACKGROUND

Esophageal strictures in children that develop as a result of accidental ingestion of corrosive substances remain an important health problem. The purpose of this study is to determine the effects of Hesperidin, an effective bioflavonoid in the proliferative and exudative phase of inflammation, on the stricture formation in corrosive esophageal burns.

METHODS

Experimental esophageal burns in rats were created using a modified Gehanno and Guedon model with 20% NaOH. Rats were divided into 5 groups. In the Sham group, the distal esophagus was prepared and cannulated according to the model, but no NaOH was administrated. The esophageal burn was created with NaOH in the other groups. The burned groups were divided into two groups as untreated (T¹⁴, T²¹) and treated with 100 mg/kg/day Hesperidin (H¹⁴, H²¹) intraperitoneally, and these groups were divided into two according to their sacrification periods (14 and 21 days). Inflammation, fibrosis, and necrosis were graded by histopathological evaluation in all groups. The efficacy of treatment was evaluated using the weight of rats, stenosis index, and histopathological parameters.

RESULTS

Histopathologic damage scores such as inflammation, necrosis, and fibrosis were lower in the H¹⁴ and H²¹ groups and higher in the T¹⁴ and T²¹ groups. And also stenosis index was found higher in T¹⁴ and T²¹ groups (p < 0.05), while it was similar to the Sham group in H¹⁴ and H²¹ groups. No statistically significant difference was found between the H¹⁴ and H²¹ groups in terms of stenosis index. When weights of the rats at the beginning and end of the experiment were compared, weights of the H¹⁴ and H²¹ groups and the Sham group were similar. There was a significant decrease in the weight of the rats in the T¹⁴ and T²¹ groups (p < 0.001).

CONCLUSIONS

This study is the first to use Hesperidin in preventing esophageal damage in an esophageal caustic burn model. It was shown that Hesperidin was effective in reducing macroscopic and microscopic histopathologic damage in the corrosive esophageal burn model, preventing the stricture formation, and has positive effects on nutrition in rats with an esophageal burn.

Effectiveness of Hypericum perforatum Extract in the Treatment of Corrosive Esophageal Burns

PURPOSE

The purpose of our study is to determine the effectiveness of "Hypericum perforatum" extract in corrosive esophageal burns and to shed light on the search for new treatments.

MATERIALS AND METHODS

A total of 32 Sprague Dawley rats were separated into 4 groups. A standard esophageal burn model was created. Group 1 was identified as the sham group. Group 2 was burned and no treatment was performed afterward. Group 3 was burned and then 2 cc/day H. perforatum extract was given for 21 days. Group 4 was not applied any process and 2 cc/day H. perforatum extract was given for 21 days. The rats were sacrificed and biopsy specimens were taken for histopathological examination for the presence of inflammation, fibrosis, and necrosis.

RESULTS

There was a significant difference between groups in terms of inflammation, fibrosis, and necrosis. Furthermore, in the bilateral comparisons between the groups, there was a meaningful difference in terms of inflammation and fibrosis between Group 2 and Group 3. However, there was no meaningful difference between the same groups in terms of necrosis.

CONCLUSION

H. perforatum extract may be effective on inflammation, fibrosis, and necrosis in corrosive esophageal burns.

Evaluation of the efficacy of Hypericum perforatum (St. John's wort) oil in the prevention of stricture due to esophageal corrosive burns

BACKGROUND/PURPOSE

The inflammatory response that follows the caustic burns results in fibrosis on the esophageal wall leading to esophageal stricture, dysphagia, and malnutrition. The controversy over the use of corticosteroids warrants alternative therapeutic interventions. We investigated the effect of extracts from St. John's wort (SJW) with known wound-healing activity on stricture formation in rat esophageal injury models.

METHODS

Five experimental groups were involved: sham group with no injury, control group with injury without treatment, and three different treatment groups (methylprednisolone, SJW extract, and combination of the two). Histopathological examination of esophageal damage and collagen accumulation, stenosis index, and tissue hydroxyproline levels were used to assess stricture and the effect of treatments.

RESULTS

There was a significant weight loss in all groups except for those without injury and those treated with SJW extract, the latter gained weight albeit not significant. Stenosis index was increased in all groups compared to sham but not significantly in those treated with SJW extract. Histopathological and biochemical analyses produced mixed results.

CONCLUSIONS

Some of the experimental indicators such as weight gain and stenosis index suggested the treatment of esophageal injury models using extracts of St. John's wort effective while other histopathological indicators show no significant benefit.

Effects of Carvacrol in an Experimentally Induced Esophageal Burn Model: Expression of VEGF and Caspase-3 Proteins

INTRODUCTION

We investigated the therapeutic effects of carvacrol in an experimental esophageal burn rat model with immunohistochemical techniques. Materials and Methods: Three groups were included in this study, composed of eight Wistar albino rats each. The control group was given 1 mL 0.9% (wt/vol) NaCl; esophageal burns were induced in groups 2 and 3 by administration of 1 mL 40% NaOH in the distal 2 cm of the esophagus. The treatment group was administered 75 mg/kg carvacrol in 2 mL 0.9% NaCl for 10 days. After a routine histological examination of the tissues, sections were stained with vascular endothelial growth factor (VEGF) and caspase-3 for immunohistochemical analysis and were examined under a light microscope. Results: In the control group, there were regular cells in the cornified epithelial tissue and cylindrical cells in the basal layer, which faced toward the apical surface in the mitotic phase. The burn group displayed wide degeneration, necrosis, and abundant apoptotic cells in the epithelial tissue as well as intense inflammatory cell infiltration. In the treatment group, there was an increase in mitotic activity in the basal cells of the epithelial layer and degenerative changes, but a preserved epithelial layer and significant cornified structures. The treatment group showed positive caspase-3 expression in some apoptotic cells within the epithelial layer and in connective tissue, and there were only a small number of degenerated cells in the muscle layer. Additionally, in the treatment group, VEGF expression was evident in small numbers of inflammatory cells in the papillary region of the epithelium, and in dilated vascular endothelial cells. Conclusions: Carvacrol may contribute to a reduction in fibrosis by decreasing inflammation and preventing cell apoptosis.

Comparison of two porcine benign esophageal stricture models using radiofrequency ablation and endoscopic submucosal tunnel dissection

BACKGROUND/AIMS

Large-animal benign esophageal stricture (BES) models are needed for the development of new endoscopic therapies and related devices. This study was undertaken to develop and compare swine BES models produced by radiofrequency ablation (RFA) or endoscopic submucosal tunnel dissection (ESTD).

MATERIALS AND METHODS

RFA and ESTD were each performed on three pigs. Follow-up endoscopy and esophagography were performed immediately after the procedures and then 2, 3, and 4 weeks later. Four weeks after the procedures, all animals were sacrificed, and gross and histologic examinations were performed.

RESULTS

BES was successfully achieved in both the RFA and ESTD groups, and all animals survived without any serious adverse events during the 4-week follow-up period. Mean procedural times were 9.3 min for RFA and 89.3 min for ESTD. ESTD caused long segment strictures whose average length was 4.5 cm, whereas RFA produced short strictures whose average length was 1.4 cm. BES began to form 2 weeks after both procedures. Degrees of strictures were similar at 3 and 4 weeks in the ESTD group; however, it started deteriorating over time in the RFA group. Histologic examinations showed that ESTD caused inflammation and fibrosis in the submucosal layer, whereas RFA induced extensive inflammation in the submucosal and muscularis propria layers.

CONCLUSION

BES was successfully achieved using RFA or ESTD in swine without serious complications. The methods have different characteristics; therefore, researchers should choose the method more appropriate for their purposes.

Topical Mitomycin C Application Is Effective Even in Esophageal Strictures Resistant to Dilatation Therapy in Children

PURPOSE

Several treatment techniques may be used in the treatment of esophageal strictures. The purpose of this study was to present the effects of topical mitomycin C (TMC) as an useful adjunct to dilatation therapy in esophageal strictures.

MATERIALS AND METHODS

A retrospective analysis of patients who underwent TMC between February 2015 and July 2016 was performed. Dysphagia score, periodic dilatation index, and number of dilatations were compared before and after intervention to investigate the efficacy of TMC.

RESULTS

TMC was performed on 20 patients with a median age of 3.5 years (2 to 17 y). The diagnosis was corrosive esophageal strictures in 14 patients, anastomotic strictures in 5 patients, and congenital esophageal stricture in 1 patient. The length of the stricture was long in 10 patients (50%). The median dysphagia score decreased from 2 (1 to 3) to 0 (0 to 2) after application (P<0.001). The median number of dilatation sessions decreased from 5 (1 to 41) to 1 (0 to 11) after intervention (P<0.001). The median periodic dilatation index decreased from 1 (0.66 to 1.34) to 0 (0 to 1.33) after TMC (P<0.001). Regular esophageal dilatation was not necessary in 16 patients after application (80%). The length of the stricture did not affect the efficacy of TMC. The success of treatment was lower in patients with a long treatment period before TMC (>3 y) (50%). No complications were seen in a median follow-up period of 16 months (7 to 22 mo).

CONCLUSIONS

TMC application has a significant positive effect as an adjunct to dilatation therapy in most of the patients with different types of esophageal strictures. It should be performed as a safe and efficient treatment option even in patients who were resistant to dilatation therapy.

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.

Management of esophageal caustic injury

Ingestion of caustic substances and its long-term effect on the gastrointestinal system maintain its place as an important public health issue in spite of the multiple efforts to educate the public and contain its growing number. This is due to the ready availability of caustic agents and the loose regulatory control on its production. Substances with extremes of pH are very corrosive and can create severe injury in the upper gastrointestinal tract. The severity of injury depends on several aspects: Concentration of the substance, amount ingested, length of time of tissue contact, and pH of the agent. Solid materials easily adhere to the mouth and pharynx, causing greatest damage to these regions while liquids pass through the mouth and pharynx more quickly consequently producing its maximum damage in the esophagus and stomach. Esophagogastroduodenoscopy is therefore a highly recommended diagnostic tool in the evaluation of caustic injury. It is considered the cornerstone not only in the diagnosis but also in the prognostication and guide to management of caustic ingestions. The degree of esophageal injury at endoscopy is a predictor of systemic complication and death with a 9-fold increase in morbidity and mortality for every increased injury grade. Because of this high rate of complication, prompt evaluation cannot be overemphasized in order to halt development and prevent progression of complications.

Caustic ingestion in children-A review

Various domestic or industrial chemicals may cause significant upper aerodigestive tract burns. Preventive measures should be up-scaled, especially in the developing world, to reduce the epidemic of accidental victims, largely unsupervised preschool children. External signs do not predict degree of injury. Non-invasive diagnostic screening includes radio-nuclear imaging, but early oesophago-gastroduodenoscopy remains the standard to predict stricture formation from circumferential submucosal scarring. Serial dilation is the mainstay of oesophageal stricture therapy, with oesophageal replacement reserved for severe refractory strictures. Intra-lesional steroid or mitomycin C may decrease the dilatations required for severe strictures, although long-term effects are unknown. Risk of secondary oesophageal carcinoma mandates long-term surveillance.

Treatment of Refractory Gastrointestinal Strictures With Mitomycin C: A Systematic Review

BACKGROUND AND AIMS

Refractory benign gastrointestinal (GI) strictures represent a difficult management problem given the limited therapeutic interventions available. We performed a systematic review of all published cases using mitomycin C in the treatment of GI strictures.

METHODS

Searches of MEDLINE and Embase databases were performed to identify studies reporting application of mitomycin C for GI strictures. Review of titles/abstracts, full review of potentially relevant studies, and data abstraction were performed independently by 2 authors.

RESULTS

Of 549 citations, 24 studies with 145 patients (74% pediatric and 26% adult) met inclusion criteria. Esophageal strictures were the most common (79%) site of refractory strictures treated with mitomycin C, with caustic injury the most common underlying etiology. The concentration (range, 0.1 to 2 mg/mL; median, 0.4 mg/mL), number of applications (range, 1 to 12; median, 1), duration of applications (range, 1 to 5; median, 2 min), and technique of application (cotton pledget, spray, injection, special catheters) varied among studies. Ninety-one patients (73%; children: 80%, adults: 59%) had a complete response; 26 (21%) had a partial response. Only 1 (0.7%) adverse event was reported: cutaneous sclerosis attributed to microperforation and mitomycin C extravastion after injection. Mean follow-up was 23 (4 to 60) months.

CONCLUSIONS

Local mitomycin C application seems to be a safe and effective therapy for benign refractory GI strictures of varying etiology in both pediatric and adult populations. Although the results of this systematic review are highly encouraging, it should be considered investigational. Additional randomized trials and larger prospective studies are needed to confirm these results and to better define the optimal dose, concentration, duration and technique of mitomycin C application.

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.

Topical mitomycin-C application in recurrent esophageal strictures after surgical repair of esophageal atresia

OBJECTIVES

The aim of the present study was to evaluate the efficacy and short-term safety of topical mitomycin-C, an antifibrotic agent, in preventing the recurrence of anastomotic strictures after surgical repair of esophageal atresia (EA).

METHODS

We retrospectively reviewed the medical records of patients with recurrent anastomotic strictures after EA surgery who underwent at least 3 esophageal dilations. We compared the outcome (ie, resolution of the stricture) of the group that received topical mitomycin-C treatment with endoscopic esophageal dilation with a historical cohort treated by dilations alone.

RESULTS

A total of 11 children received mitomycin-C concurrently with endoscopic dilations. After a median follow-up of 33 months (range 18-72), and a mean number of 5.4 dilations per patient (range 3-11), 8 of 11 patients achieved a resolution of their strictures, 2 patients remained with stenosis, and 1 patient needed a surgical correction. In the control group, 10 patients required an average of 3.7 (range 3-7) total dilations. After a follow-up of 125 months (range 35-266) after the last dilation, strictures in 9 of 10 children disappeared and the remaining patient was symptom free. No dysplasia related to mitomycin-C was demonstrated.

CONCLUSIONS

There is no benefit in the resolution of the stricture when adding mitomycin-C treatment compared with repeated esophageal dilations alone in historical controls. Further randomized controlled studies and a short- and long-term evaluation of safety are needed.

Esophageal stricture induced by an ultraslim upper endoscope in a novel rabbit model of corrosive injury

OBJECTIVE

Benign esophageal strictures are regularly encountered problems in clinical practice. The management of refractory benign esophageal stricture, which fails to establish adequate food passage despite multiple dilatation sessions, has been considered challenging. Experimental animal models are essential for the development of effective treatment methods. The aim of this study was to establish a new animal model of benign esophageal stricture using rabbits.

MATERIAL AND METHODS

Corrosive injury of the esophagus was induced by administration of 1 ml of 1.5% sodium hydroxide in eight rabbits using an ultraslim upper endoscope equipped with a 5-Fr polytetrafluoroethylene tube and 5-Fr balloon catheter. Two weeks after corrosive injury, endoscopic examination was performed to confirm the state of the injury site. Four weeks after corrosive injury, the esophageal stricture was assessed by endoscopy and esophagography. All animals were then euthanized.

RESULTS

Two weeks after corrosive injury, endoscopic examination showed that ulceration had been induced. Four weeks after corrosive injury, endoscopic, radiologic and gross examinations showed that esophageal stricture had been induced without complications in all animals. The esophageal lumen diameter was reduced by an average of 51.8% (range, 48.3%-57.2%), and the mean stricture length was 25.7 mm (range, 20.1-29.3 mm). Microscopic examination revealed focal ulceration and submucosal thickening secondary to fibrosis.

CONCLUSIONS

Rabbit esophageal stricture induced by endoscopic delivery of a small amount of low-concentration sodium hydroxide is a relatively simple, safe, and reproducible animal model. This model may be useful in the development of new treatment methods for esophageal stricture.

Preliminary results of antiscarring therapy in the prevention of postendoscopic esophageal mucosectomy strictures

BACKGROUND

Esophageal endoscopic submucosal dissection (ESD) is an effective minimally invasive therapy for early esophageal cancer and high-grade Barrett dysplasia. However, esophageal stricture formation after circumferential or large ESD has limited its wide adoption. Mitomycin C (MMC), halofuginone (Hal), and transforming growth factor β3 (TGF-β3) exhibits antiscarring effects that may prevent post-ESD stricture formation.

METHODS

Using endoscopic mucosectomy (EEM) technique, an 8- to 10-cm-long circumferential esophageal mucosal segment was excised in a porcine model. The site was either untreated (control, n = 6) or received 40 evenly distributed injections of antiscarring agent immediately and at weeks 1 and 2. High and low doses were used: MMC 5 mg (n = 2), 0.5 mg (n = 2); Hal 5 mg (n = 2), 1.5 mg (n = 2), 0.5 mg (n = 2); TGF-β3 2 μg (n = 2), 0.5 μg (n = 2). The degree of stricture formation was determined by the percentage reduction of the esophageal lumen on weekly fluoroscopic examination. Animals were euthanized when strictures exceeded 80 % or the animals were unable to maintain weight.

RESULTS

The control group had a luminal diameter reduction of 78.2 ± 10.9 % by 2 weeks and were euthanized by week 3. Compared at 2 weeks, the Hal group showed a decrease in mean stricture formation (68.4 % low dose, 57.7 % high dose), while both TGF-β3 dosage groups showed no significant change (65.3 % low dose, 76.2 % high dose). MMC was most effective in stricture prevention (53.6 % low dose, 35 % high dose). Of concern, the esophageal wall treated with high-dose MMC appeared to be necrotic and eventually led to perforation. In contrast, low dose MMC, TGF-β3 and Hal treated areas appeared re-epithelialized and healthy.

CONCLUSIONS

Preliminary data on MMC and Hal demonstrated promise in reducing esophageal stricture formation after EEM. More animal data are needed to perform adequate statistical analysis in order to determine overall efficacy of antiscarring therapy.

Topical mitomycin C application is effective in management of localized caustic esophageal stricture: a double-blinded, randomized, placebo-controlled trial

BACKGROUND

Frequent sessions of endoscopic dilatation are usually required in the management of benign esophageal strictures, especially caustic induced ones. Topical mitomycin C (MMC) has been recently used in the management of resistant strictures. This study evaluated the efficacy of MMC application in prevention of stricture recurrence after endoscopic dilatation.

PATIENTS AND METHODS

This double-blind, randomized, placebo-controlled trial included forty patients with caustic esophageal strictures dating from January 2008 to October 2010. Patients were randomized into 2 groups to undergo endoscopic dilatation with application of either MMC versus placebo on stricture site. Regular follow up and re-evaluation were done after 6 months of management. The number of dilatation sessions needed for resolution of dysphagia in each group was our primary outcome.

RESULTS

During the specified follow up period, 80 % of strictures in the MMC group got completely resolved compared to only 35% in the placebo group. The mean number of dilatation sessions needed in the MMC group was n = 3.85 ± 2.08 compared to n = 6.9 ± 2.12 in the placebo group which was statistically significant (p < 0.001).

CONCLUSION

Mitomycin C application significantly reduced the number of dilatation sessions needed to alleviate dysphagia in patients with caustic esophageal strictures.

Topical Mitomycin C application for esophageal stricture: safe, precise, and novel endoscopic technique

PURPOSE

The first line of management of benign esophageal stricture is endoscopic dilatation; however, multiple sessions are usually indicated especially in resistant cases. Topical Mitomycin C (MCC) application is a new adjuvant treatment in the management of esophageal stricture with promising results in different case series. Several techniques have been reported for application; nevertheless, the ideal technique has not been described yet.

MATERIAL AND METHODS

In this series we have devised a new technique using both the flexible and the rigid endoscope and a specially designed Nelaton catheter.

RESULTS

This technique was applied in 38 sessions for 16 caustic esophageal strictures with technical success in all cases. No procedure-related complications were observed in this series.

CONCLUSION

This novel technique is feasible and effective and can be considered as standard for topical MMC application on esophageal stricture.

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.

Topical mithramycin-A modulates submucosal collagen deposition after esophageal burn injury in rats

OBJECTIVE

To evaluate efficacy of a drug-eluting, dissolvable esophageal (DEDE) stent for the prevention of submucosal collagen deposition in a rat model of acute esophageal injury.

SETTING

University laboratory.

STUDY DESIGN

Interventional randomized controlled trial.

SUBJECTS AND METHODS

Forty two adult, male, age-matched Sprague Dawley rats were randomized to undergo either sham esophageal surgery, esophageal burn injury, or esophageal burn injury and placement of a DEDE stent. All animals underwent open gastrotomy under anesthesia. In group 1, a cautery device was inserted through the gastrotomy into the distal esophagus and removed without creating an injury. In group 2, the cautery was placed in the distal esophagus and a circumferential thermal burn injury was created. In group 3, an identical burn injury was created and a DEDE stent was placed at the site of injury and secured. On postoperative day 28, animals were sacrificed, and the distal esophagi were harvested and processed for histology. Submucosal collagen area was quantified histologically and compared across the 3 experimental groups.

RESULTS

After the investigators controlled for luminal circumference and multiple measurements, submucosal collagen area was increased in group 2 (burn) compared with group 1 (sham) (P = .012). Submucosal collagen area was decreased in group 3 (DEDE stent) compared with group 2 (P = .042). No statistically significant difference in submucosal collagen area was observed between animals in group 1 and group 3 (P = .800). CONCLUSIONS;Topical application of mithramycin-A via a DEDE stent modulates collagen deposition after acute thermal injury in the rat esophagus.

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.