Submucosal injection: safety cushion at what cost?

Injectable temperature-sensitive hydrogel facilitating endoscopic submucosal dissection

Purpose: Early gastrointestinal tumors can be removed by endoscopic procedures. Endoscopic mucosal dissection (ESD) requires submucosal fluid injection to provide mucosal elevation and prevent intraoperative perforation. However, the clinically applied normal saline mucosal elevation height is low for a short time, which often requires multiple intraoperative injections that increase the inconvenience and procedure time. In addition, recently researched submucosal injection materials (SIM) suffer from complex preparation, poor economy, and poor biocompatibility. Therefore, there is an urgent need for a new type of SIM that can provide long, safe and effective mucosal elevation in support of the endoscopic procedures. Methods: The FS hydrogel is based on polyethylene-polypropylene glycol (F-127) mixed with sodium alginate (SA). The different physicochemical properties of FS hydrogels were characterized through various experiments. Afterward, various biosafety assessments were carried out. Finally, the performance of FS hydrogels was evaluated by in vitro submucosal injection and in vivo swine ESD. Results: The experimental results show that the FS hydrogel is liquid at room temperature, making it easy to inject, and when injected under the mucosa, it undergoes temperature-induced cross-linking, transforming from a liquid to a solid state to provide long-lasting mucosal augmentation. At the same time, the FS hydrogel exhibits controllable gelation, stability, and biocompatibility. The results of in vitro submucosal injections and in vivo ESD procedures showed that FS achieves high mucosal augmentation and provides good submucosal cushioning in the long term. Conclusion: In summary, the F-127/SA hydrogel is simple to synthesize, cost-effective, safe, easy to store, and able to assist ESD well from the perspective of practical clinical problems, indicating that the FS hydrogel can be an ideal potent submucosal injection substitution.

Efficacy and safety of a submucosal injection solution of sodium alginate for endoscopic resection in a porcine model

Endoscopic resection techniques require the use of submucosal injection. Normal saline and sodium hyaluronate solutions are mainly used for this purpose, but an ideal solution has not yet been developed. The aim of this study was to assess a new solution, MC-003-a novel submucosal injection solution developed with sodium alginate as the main ingredient. Normal saline, a commercial sodium hyaluronate solution (Endo-Ease), and MC-003 were examined. A total of 18 gastric submucosal cushions were created in the stomachs of six pigs. The height of mucosal elevation was measured sequentially using endoscopic sonography. After euthanizing the animals either 2 h or 5 days after the procedure, pathologic examination was performed for each injection site. Although not statistically significant over the entire study period, MC-003 showed a superior result to normal saline and an equivalent result to Endo-Ease in the submucosal cushion height and its rate of decrease. There were no adverse outcomes after injection of the three solutions and there was no pathologically identified detrimental change in the resected specimens. MC-003 creates a sufficient submucosal fluid cushion without apparent tissue damage. It can be considered as an effective submucosal injection material.

Easily-injectable shear-thinning hydrogel provides long-lasting submucosal barrier for gastrointestinal endoscopic surgery

Submucosal injection material has shown protective effect against gastrointestinal injury during endoscopic surgery in clinic. However, the protective ability of existing submucosal injection material is strictly limited by their difficult injectability and short barrier time. Herein, we report a shear-thinning gellan gum hydrogel that simultaneously has easy injectability and long-lasting barrier function, together with good hemostatic property and biocompatibility. Shear-thinning property endows our gellan gum hydrogel with excellent endoscopic injection performance, and the injection pressure of our gellan gum hydrogel is much lower than that of the small molecule solution (50 wt% dextrose) when injected through the endoscopic needle. More importantly, our gellan gum hydrogel shows much stronger barrier retention ability than normal saline and sodium hyaluronate solution in the ex vivo and in vivo models. Furthermore, our epinephrine-containing gellan gum hydrogel has a satisfactory hemostatic effect in the mucosal lesion resection model of pig. These results indicate an appealing application prospect for gellan gum hydrogel utilizing as a submucosal injection material in endoscopic surgery.

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Submucosal injection materials are widely used in endoscopic surgery to protect against gastrointestinal injury.

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Gellan gum hydrogel with shear-thinning character is a novel submucosal injection material.

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Gellan gum hydrogel simultaneously has easy injectability and long-lasting barrier performance in vivo.

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Epinephrine-containing gellan gum hydrogel has a satisfactory hemostatic effect.

Efficacy and Safety of a Novel Submucosal Injection Solution for Resection of Gastrointestinal Lesions

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are minimally invasive and efficient techniques for the removal of gastrointestinal (GI) mucosal polyps. In both techniques, submucosal injection solutions are necessary for complete effectiveness and safety during the intervention to be obtained. The main objective of this study was to evaluate the efficacy and safety of a new sterile submucosal injection solution for EMR/ESD used within a clinical protocol in patients with intestinal polyps. We carried out a prospective study between 2016 and 2017 with patients who attended the Endoscopy Consultation—Digestive Department of Primary Hospital. Patients were selected for EMR/ESD after the application of clinical protocols. Thirty-six patients were selected (≥ 66 years with comorbidities and risk factors). Lesions were located mainly in the colon. Our solution presented an intestinal lift ≥ 60 min in EMR/ESD and a high expansion of tissue, optimum viscosity, and subsequent complete resorption. The genes S100A9 and TP53 presented an expression increase in the distal regions. TP53 and PCNA were the only genes whose expression was increased in polyp specimens vs. the surrounding tissue at the mRNA level. In EMR/ESD, our solution presented a prolonged effect at the intestinal level during all times of the intervention. Thus, our solution seems be an effective and safe alternative in cases of flat lesions in both techniques.

Usefulness of Ready-to-Use 0.4% Sodium Hyaluronate (Endo-Ease) in the Endoscopic Resection of Gastrointestinal Neoplasms

BACKGROUND/AIMS

Commercially available sodium hyaluronate solutions are usually too thick to inject through catheters and need dilution with normal saline (NS) before use, which increases the risk of contamination. We evaluated the usefulness of ready-to-use 0.4% sodium hyaluronate, Endo-Ease (EE; UNIMED Pharm. Inc., Seoul, Korea).

METHODS

We performed a prospective multicenter randomized study from May 2011 to September 2012. Patients requiring endoscopic resection (ER) for gastric or colorectal neoplasm at two referral hospitals were enrolled.

RESULTS

One hundred fifty-four patients (72 with a gastric neoplasm and 82 with a colorectal neoplasm) were included in intention-to-treat analysis. Thirty-seven gastric neoplasms and 43 colorectal neoplasms were enrolled in the EE group. The usefulness rate was significantly higher in the EE group than in the NS group (89.2% vs. 60.0% for gastric neoplasms and 95.3% vs. 67.7% for colorectal neoplasms, p<0.001). In the EE group, the ease of mucosal resection was significantly higher than in the NS group (p<0.001). The injected volume was smaller in the EE group than in the NS group (p<0.05).

CONCLUSIONS

The use of EE reduced the need for additional injections and improved the ease of ER. A submucosal injection of EE is useful for the ER of both gastric and colorectal neoplasms.

Acute appendicitis following endoscopic mucosal resection of cecal adenoma

Endoscopic mucosal resection (EMR) allows the removal of flat or sessile lesions, laterally spreading tumors, and carcinoma of the colon or the rectum limited to the mucosa or the superficial submucosa. Acute appendicitis is the most common abdominal emergency requiring emergency surgery, and it is also a rare complication of diagnostic colonoscopy and therapeutic endoscopy, including EMR. In the case presented here, a 53-year-old female underwent colonoscopy due to a positive fecal occult blood test and was diagnosed with cecal adenoma. She was referred to our hospital and admitted for treatment. The patient had no other symptoms. EMR was performed, and 7 h after the surgery, the patient experienced right -lower abdominal pain. Laboratory tests performed the following day revealed a WBC count of 16000/mm³, a neutrophil count of 14144/mm³, and a C-reactive protein level of 2.20 mg/dL, indicating an inflammatory response. Computed tomography also revealed appendiceal wall thickening and swelling, so acute appendicitis following EMR was diagnosed. Antibiotics were initiated leading to total resolution of the symptoms, and the patient was discharged on the sixth post-operative day. Pathological analysis revealed a high-grade cecal tubular adenoma. Such acute appendicitis following EMR is extremely rare, and EMR of the cecum may be a rare cause of acute appendicitis.

Electrical characteristics of various submucosal injection fluids for endoscopic mucosal resection

Submucosal fluid injection, prerequisite to endoscopic mucosal resection, necessitates detailed evaluation for proper selection. We aimed to compare height of gastric tissues after submucosal injection, and to verify electrical implications of injectants. Porcine stomach pieces were cut out, and eight solutions were used: normal saline, 0.5% sodium hyaluronate (SH), 0.25% SH, hydroxypropyl methylcellulose, 10% glycerin, fibrinogen, 1% sodium alginate (SA), and 2.5% SA. Elevated heights were measured after submucosal injection of the eight fluids, and electrical impedance was measured for fluids plus a reference solution (0.01 N KCl) with a potentiostat electroimpedance spectrometry and an insulation-tipped knife. Resistivity was calculated thereafter. Normal saline and 10% glycerin solution showed greater height diminution. Resistivity were in the range of 80-110 Omega cm, except for 309.7 Omega cm for fibrinogen. Higher resistivity may improve performance of electrosurgery, probably by strengthening impedance and heat dissipation. Further studies are required to back up this basic experiment for clinical application.

En bloc endoscopic submucosal dissection of a 14-cm laterally spreading adenoma of the rectum with involvement to the anal canal: expanding the frontiers of endoscopic surgery (with video)

BACKGROUND

Endoscopic submucosal dissection (ESD) was recently developed in Japan for en bloc removal of laterally spreading tumors (LSTs). Although initially used for gastric tumors, ESD has now been applied to lesions elsewhere in the gut. Recent reports from Japan included removal of colorectal lesions up to 10 cm.

OBJECTIVE

To show the feasibility of ESD to remove en bloc, very large LSTs of the rectum, even when there is involvement to the dentate line.

DESIGN

Case report.

SETTING

The procedure was performed at an American GI unit. The patient was admitted to the hospital after the procedure for observation.

PATIENTS

A 53-year-old patient, with a 14-cm tubulovillous adenoma of the rectum, which, at its maximal extent, involved two thirds of the circumference of the rectum. The tumor extended distally to the dentate line.

INTERVENTIONS

En bloc submucosal dissection with a conventional needle-knife to remove the neoplasm.

MAIN OUTCOME MEASUREMENTS

Completeness of en bloc removal of the tumor and subsequent follow-up endoscopy that showed no residual neoplasm.

RESULTS

The tumor was able to be removed en bloc by ESD. The distal margin included squamous mucosa. At a 2.5-week endoscopic follow-up, a 3-mm focus of residual polyp was seen and removed. At the time of the last follow-up, there was complete healing of the wound and no residual neoplasm.

LIMITATIONS

Single case.

CONCLUSIONS

This case demonstrated the feasibility of using ESD to remove large laterally spreading rectal tumors, including when there was involvement to the dentate line (and the dissection line must include squamous mucosa of the anal canal). ESD is a promising alternative to conventional surgical techniques; however, additional published experience is needed.

Clinical efficacy of EMR with submucosal injection of a fibrinogen mixture: a prospective randomized trial

BACKGROUND

Submucosal injection is essential to performing EMR easily, and various solutions have been proposed to create a long-lasting submucosal fluid cushion.

OBJECTIVE

To assess the efficacy of a fibrinogen mixture (FM) as a submucosal injection solution.

DESIGN

A prospective, randomized, controlled trial.

SETTING

At a tertiary care, academic medical center.

PATIENTS

A total of 72 patients with early gastric neoplasm were randomly assigned to receive EMR with submucosal injection of normal saline solution (NS) or an FM.

INTERVENTION

We performed EMR only with a conventional method.

MAIN OUTCOME MEASUREMENTS

En bloc resection rate, complete resection rate, complications, and other procedure-related outcomes.

RESULTS

No significant differences were observed between the 2 groups (the FM group vs the NS group) in the rates of en bloc resection (80.6% vs 88.9%), complete resection rate (86.1% vs 80.6%), and recurrence rate (3% vs 6.1%). Mean procedure time was significantly shorter in the FM group vs the NS group (11.39 +/- 3.07 minutes vs 13.93 +/- 3.26 minutes; P < .05). Mean submucosal injection volume of the FM group was significantly less than that of the NS group (9.81 +/- 2.26 mL vs 14.32 +/- 2.35 mL; P < .05). Also, additional submucosal injection to maintain elevation of the lesion was less frequently required in the FM group than in the NS group (5.6% vs 33.3%; P < .05).

LIMITATIONS

The main limitations were the method of EMR (only included the conventional method) and the size of lesions (<30 mm), because a long-lasting submucosal fluid cushion was more important in the dissection method and larger tumors.

CONCLUSIONS

The FM is a reliable submucosal injection solution for conventional EMR.

Endoscopic mucosal resection of large sessile colorectal polyps with submucosal injection of hypertonic 50 percent dextrose-epinephrine solution

PURPOSE

Before endoscopic mucosal resection of large sessile colorectal polyps, injection of solution into submucosa cushions and isolates the tumor, although there is little information as to which solution with optimal effect should be used. This study investigated the effectiveness of endoscopic mucosal resection by use of a hypertonic dextrose plus epinephrine solution for large sessile colorectal polyps.

METHODS

We removed 59 large sessile colorectal polyps in 59 patients by introducing an endoscopic submucosal hypertonic dextrose plus epinephrine injection technique. Endoscopic evaluations were repeated at 3, 6, and 12 months or longer. If no residual tumor was observed endoscopically and histologically at one year or more, the patient was considered to be "cured." The main outcome measurements were the mean amount of solution injected, mean disappearance time of solution, safety, complications, and recurrence at follow-up.

RESULTS

Of the 59 large sessile colorectal polyps, 23 (39 percent) were resected en bloc and 36 (61 percent) piecemeal. The mean amount of hypertonic dextrose plus epinephrine solution injected was 24.42 +/- 17.52 ml, and its mean disappearance time was 13.61 +/- 5.21 (range, 7-21) minutes. Of the 36 patients treated with piecemeal resection, 18 (50 percent) required additional endoscopic interventions. In patients who entered the follow-up surveillance protocol for one year or longer, the cure rate by en bloc resection was 100 percent (23/23) and that by piecemeal intervention was 96.78 percent (30/31). Four patients (6.8 percent) had local bleeding after endoscopic mucosal resection that was mainly controlled endoscopically.

CONCLUSIONS

Endoscopic mucosal resection after submucosal hypertonic dextrose plus epinephrine solution injection, with an intensive follow-up program, seems to be a safe and effective treatment for large sessile colorectal polyps.