The roles of connective tissue growth factor in the development of anastomotic esophageal strictures

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.

Anastomotic stenosis following proximal gastrectomy with single flap valvulopasty successfully managed with endoscopic stricturotomy: a case report

Background

Due to its nutritional advantages over total gastrectomy, proximal gastrectomy (PG) with anti-reflux techniques has gained significant attention in East Asian countries in recent years. The double flap technique (DFT) and modified side overlap and fundoplication by Yamashita (mSOFY) are two promising anti-reflux interventions following PG. However, anastomotic stenosis after DFT and gastroesophageal reflux after mSOFY have been reported in several patients. To address these concerns, a hybrid reconstruction procedure was designed, namely, right-sided overlap with single flap valvulopasty (ROSF), for proximal gastrectomy, with the aim of reducing anastomotic stricture and reflux. Among the 38 patients who underwent ROSF at our hospital, one developed Stooler grade II anastomotic stenosis. Herein, we present the successful management of this patient through endoscopic stricturotomy (ES).

Case summary

A 72-year-old female complaining of "epigastric pain and discomfort for more than 1 month" was diagnosed with adenocarcinoma of the esophagogastric junction (Siewert type II). She underwent laparoscopic-assisted PG and ROSF procedures at our hospital and recovered well after surgery. However, she started experiencing progressive difficulty in eating and vomiting approximately 3 weeks after the intervention. Endoscopy revealed Stooler grade II esophagogastric anastomotic stenosis. ES with insulated tip (IT) Knife nano was eventually performed, and the patient was able to resume a normal diet without experiencing any discomfort during the 5-month follow-up period.

Conclusion

Endoscopic stricturotomy using IT Knife nano successfully treated anastomotic stenosis following ROSF with no associated complications. Thus, ES to treat anastomotic stenosis after PG with valvulopasty can be considered a safe option and should be performed in centers with the required expertise.

Management of benign anastomotic strictures following rectal resection: a systematic review

AIM

Benign anastomotic strictures following colorectal surgical resection are a commonly under-reported complication in up to 30% of patients, with a significant impact upon quality of life. In this systematic review, we aim to assess the utility of endoscopic techniques in avoiding the need for surgical reintervention.

METHOD

A literature search was performed for published full text articles using the PubMed, Cochrane and Scopus databases. Additional papers were found by scanning the references of relevant papers.

RESULTS

A total of 34 papers were included, focusing upon balloon dilatation, endoscopic stenting, electroincision, stapler stricturoplasty and cortiocosteroids alone and in combination, with success rates varying from 20% to 100%. The most challenging strictures were reported as those with a narrow lumen, frequently observed following neoadjuvant chemoradiotherapy or an anastomotic leak. Endoscopic balloon dilatation was the most commonly used first-line method; however, repeated dilatations were often required and this was associated with an increased risk of perforation. Although initial success rates for stents were good, patients often experienced stent migration and local symptoms. Only a small number of patients experienced endoscopic management failure and progressed to surgical intervention.

CONCLUSION

Following identification of an anastomotic stricture and exclusion of underlying malignancy, endoscopic management is both safe and feasible as a first-line option, even if multiple treatment exposures or multimodal management is required. Surgical resection or a defunctioning stoma should be reserved for emergency or failed cases. Further research is required into multimodal and novel therapies to improve quality of life for these patients.

Role of endoscopic interventions and electroincision in benign anastomotic strictures following colorectal surgery

BACKGROUND/AIMS

The anastomotic strictures are one of the most common colorectal surgery complications, and various endoscopic techniques have been defined. Balloon dilation is the most well-known and the simplest procedure. In this article, we aimed to present our series of endoscopic interventions and electroincision management for anastomotic strictures.

MATERIALS AND METHODS

The files of 59 patients, who underwent colorectal surgery between January 2010 and September 2017 in our hospital and were diagnosed during the follow-up with anastomotic stricture, were analyzed. The outcomes of endoscopic interventions such as balloon dilation and electroincision were compared and reported.

RESULTS

The mean age of the 59 patients included in the study was 59.5±16.26 years. The primary operative indications were colorectal cancer in 46, inflammatory bowel disease in 7, diverticulum in 5, and penetrating trauma in one patient. Single- or multiple-balloon dilations were successful in 48 patients. Electroincision was performed in 11 patients because of the balloon dilation failure. None of the patients needed a secondary surgery. During the mean 33.75 months of the follow-up, the stricture recurred in seven patients who had undergone balloon dilation. Repeated balloon dilation was successful in these patients without any need for an additional surgical intervention.

CONCLUSION

Balloon dilation can be performed safely as the primary treatment option, because of its easy access and noninvasive application. Electroincision is also a safe and effective endoscopic technique that can be preferred especially when the balloon dilation fails.

Lentivirus-mediated silencing of the CTGF gene suppresses the formation of glial scar tissue in a rat model of spinal cord injury

BACKGROUND CONTEXT

One of the many reactive changes following a spinal cord injury (SCI) is the formation of a glial scar, a reactive cellular process whereby glial cells accumulate and surround the central nervous system injury sites to seal in the wound. Thus, the inhibition of glial scar is of great importance for SCI recovery.

PURPOSE

This study aimed to explore the effect of lentivirus-mediated silencing of the CTGF gene on the formation of glial scar tissue in a rat model of SCI.

STUDY DESIGN

This is a prospective study.

STUDY SAMPLE

A total of 56 Wistar female rats aged 8 weeks were randomly selected for this study.

OUTCOME MEASURES

The motor function of the rats was assessed using the Basso, Beattie, and Bresnahan (BBB) functional scale, footprint analysis of gait, and the Basso Mouse Scale (BMS). Quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry were performed to detect the mRNA and protein expressions of glial fibrillary acidic protein (GFAP), vimentin, fibronectin, and laminin in the spinal cord tissues.

METHODS

A rat model of SCI was successfully established. Fifty-six male Wistar rats were randomly selected and assigned into four groups (14 rats in each group): the sham operation group, the SCI model group, the negative control (NC) group (SCI rats transfected with empty vector plasmids), and the siRNA-CTGF group (SCI rats transfected with lentivirus CTGF siRNA).

RESULTS

The SCI rats showed decreased activity and were dragging their bodies while moving. Compared with the sham operation group, the BBB and BMS scores in the SCI model, NC, and siRNA-CTGF groups significantly decreased. However, the BBB and BMS scores in the siRNA-CTGF group were higher than those in the SCI model and NC groups. The mRNA and protein expressions of GFAP, vimentin, fibronectin, and laminin significantly increased in the SCI model, NC, and siRNA-CTGF groups in comparison with those in the sham operation group. Furthermore, the mRNA and protein expressions of GFAP, vimentin, fibronectin, and laminin in the siRNA-CTGF group were lower than those in the SCI model and NC groups 28 days after transfection.

CONCLUSIONS

These findings indicate that lentivirus-mediated silencing of the CTGF gene can suppress the formation of glial scar tissue after SCI.

Stem cell factor in the serum of patients with esophageal cancer in relation to its histological types

INTRODUCTION

Hematopoietic growth factors (HGFs), such as stem cell factor (SCF), may stimulate proliferation and differentiation of hematopoietic progenitor cells. Stem cell factor is also able to affect the growth of malignant tumors, including esophageal cancer (EC). The prognosis of EC patients' survival is still unfavorable. Thus, novel biomarkers are necessary to improve the diagnosis and prognosis of EC patients. The aim of this study was to determine the serum SCF concentrations in EC patients in relation to its histological types and compare these levels with the classical tumor marker - carcinoembryonic antigen (CEA).

MATERIAL AND METHODS

The study included 56 EC patients and 65 healthy controls. Serum SCF and CEA concentrations were measured using immunoenzyme assays. Moreover, diagnostic criteria of both proteins tested and the survival of EC patients were assessed.

RESULTS

The serum SCF concentrations were lower in EC patients compared to healthy controls, but the difference was not significant, whereas CEA levels were higher in EC patients than in healthy subjects. The serum SCF concentrations were significantly higher in patients with adenocarcinoma of the esophagus (AC) than in patients with esophageal squamous cell carcinoma (ESCC). Moreover, the diagnostic sensitivity of SCF (88%) was higher than for CEA (29%) and increased for combined analysis of SCF with CEA.

CONCLUSIONS

Our findings suggest the potential role of serum SCF in the diagnosis of EC patients, especially in combination with the classical tumor marker. However, due to the non-specific nature of SCF, this issue requires further investigations performed on a larger population of EC patients.

EW-7197, an activin-like kinase 5 inhibitor, suppresses granulation tissue after stent placement in rat esophagus

BACKGROUND AND AIMS

Self-expanding metallic stent (SEMS) placement is a well-established method for treating malignant esophageal strictures; however, this procedure has not gained widespread acceptance for treating benign esophageal strictures because of granulation tissue formation. The aim of the present study was to investigate whether EW-7197, a novel per-oral transforming growth factor-β type I receptor kinase inhibitor, suppressed granulation tissue formation after SEMS placement in the rat esophagus.

METHODS

Sixty rats underwent SEMS placement and were randomly divided into 4 groups. Group A (n = 20) received vehicle-treated control for 4 weeks. Group B (n = 20) received 20 mg/kg/day EW-7197 for 4 weeks. Group C (n = 10) received 20 mg/kg/day EW-7197 for 4 weeks followed by vehicle-treated control for 4 weeks. Group D (n = 10) received 20 mg/kg/day EW-7197 for 8 weeks.

RESULTS

SEMS placement was technically successful in all rats. Eleven rats, however, were excluded because of stent migration (n = 9) and procedure-related death (n = 2). The luminal diameter in group A was significantly smaller than those in groups B, C, and D (all P < .001). The percentage of granulation tissue area, number of epithelial layers, thickness of submucosal fibrosis, percentage of connective tissue area, and degree of collagen deposition were significantly higher in group A than in groups B, C, and D (all P < .001); however, there were no significant differences among groups B, C, and D. EW-7197 decreased the expression levels of phospho-Smad 3, N-cadherin, fibronectin, α-smooth muscle actin, and transforming growth factor-β1 and increased the expression level of E-cadherin (all P < .01).

CONCLUSIONS

EW-7197 suppressed granulation tissue formation after SEMS placement in the rat esophagus.

Evaluation of efficacy of endoscopic incision method in postoperative benign anastomotic strictures of gastrointestinal system

INTRODUCTION

Postoperative benign anastomotic strictures (POBAS) which develop after surgical resections of the gastrointestinal system (GIS) present with symptoms depending on location of the stricture. Diagnosis is confirmed by endoscopic and radiological methods. Although bougie or balloon dilatation is preferred in management, the endoscopic incision method (EIM) is also used with considerable success. In this trial, we aimed to evaluate EIM, which is one of the endoscopic dilatation techniques used in postoperative anastomotic stricture of GIS.

MATERIAL AND METHODS

A total of 20 POBAS patients, 12 men and 8 women, subjected to EIM intervention for strictures, were enrolled in the trial. The number of patients with upper GIS strictures was 6 (30%), while the number of cases with lower GIS strictures was 14 (70%).

RESULTS

Dilatation of the stricture was achieved in 15 (75%) patients with one treatment session, while more than one session of EIM was needed in 5 (25%) cases. Mean duration of follow-up of patients was 10.65 ±5.86 (0-25) months. Procedure-related complications developed in 8 patients. Among them, 7 were minor complications and improved without any treatment. In only 1 (5%) patient, perforation was observed as a major complication. Following EIM, recurrence of POBAS was observed in 5 (25%) patients. The following parameters were found to have an impact on successful outcome in EIM: presence or absence of a tortuous lumen in POBAS (p = 0.035) and length of stricture (p = 0.02), complications during the procedure (if any), and presence of single or multiple strictures.

CONCLUSIONS

Endoscopic incision method may be regarded as a favorable approach among first choice treatment alternatives in uncomplicated anastomotic strictures of GIS, or it may be used as an adjunctive dilatation method.