Usefulness of endoscopic ultrasound for the prediction of intraoperative bleeding of endoscopic submucosal dissection for gastric neoplasms

Design and validation of performance-oriented injectable chitosan thermosensitive hydrogels for endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD) is a challenging procedure. The use of biomaterials to improve the operator's convenience (operating affinity) has received little attention. We prepared two thermosensitive hydrogels, lactobionic acid-modified chitosan/chitosan/β-glycerophosphate thermosensitive hydrogel (hydrogel 1) and its lyophilized powders (hydrogel 2), characterized their physicochemical properties and evaluated their performance in ESD experiments on large animals, by comparing with the commonly used normal saline (NS) and glycerin fructose (GF). These hydrogels showed good low-temperature fluidity; their viscosities at 4 °C were 92.2 mPa.s and 26.9 mPa.s, respectively. The hydrogels provided significantly better viscoelastic properties than NS and GF. The relaxation moduli of hydrogels were higher than those of NS and GF when the strains were 1 %, 5 %, and 10 %. The hydrogels can be maintained for seven days, even at pH 1, after which they degrade entirely. In pig model experiments, we performed submucosal injection and ESD procedures in the stomach and esophagus. The cushion height produced by the hydrogels was higher than those of NS and GF 30 min after injection. The ESD operation time for hydrogels was significantly shorter. Postoperative wound observation and histological analysis showed that the hydrogels promoted wound healing. The two hydrogels differed in fluidity, viscoelasticity, and other properties, which makes it possible to select the hydrogels according to the size and location of the lesion during ESD operation, and hydrogel 2 may be more suitable for use in lengthier procedures. In general, the hydrogels showed good performance, facilitated the intraoperative operation of ESD, shorten the operation time and promoted wound healing, which is of great significance for reducing the complications and reducing the threshold of ESD operation and further promoting the popularity of ESD.

Examination of Endoscopic Ultrasonographic Diagnosis for the Depth of Early Gastric Cancer

Background

Endoscopic ultrasonography (EUS) is one of the helpful tools to diagnose depth of early gastric cancer (EGC). In this study, we examined efficiencies of EUS for EGC such as overall accuracy, risk factors of over/under-staging, and accuracies of each invasive distance.

Methods

A total of 403 EGC lesions that could be investigated by EUS during pre-operation and histological diagnosis after endoscopic submucosal dissection (ESD) or surgery were enrolled in this study. For the 403 cases, we analyzed the accuracies of depth by conventional endoscopy (CE) and EUS retrospectively. We evaluated the clinical survey items of CE and EUS which will be described later to compare the differences between “accuracy group” and “over-staging group”, and between “accuracy group” and “under-staging group”, retrospectively. Additionally, 78 EGC lesions which were confined to the submucosa and for which it was possible to measure accurate invasive distance from the muscularis mucosae were examined for the relationship between preoperative diagnosis of depth by CE and EUS and invasive distance retrospectively.

Results

The overall accuracies of both CE and EUS in predicting EGC invasion depth were 87.3%. For CE staging, histological classification was the factor which influenced over-staging. Gastric regions and tumor area were the factors which influenced under-staging of CE. For EUS staging, tumor area was the factor which influenced over-staging, and gastric regions were the factors which influenced under-staging. Both CE and EUS were not sufficient for predicting the lesions confined to < 500 µm from the muscularis mucosae because the accuracies of both in predicting depth were less than 50%. However, EUS has a higher accuracy than CE for the lesions confined to 500 - 2,000 µm.

Conclusions

The overall accuracies of both CE and EUS in predicting EGC invasion depth were equal, but the contributing factors for over/under-staging were different. Both CE and EUS are not sufficient at present to predict the lesions confined to < 500 µm from the muscularis mucosae. However, the accuracy of EUS in predicting them may increase if high-performance EUS systems are developed in the future.

Feasibility of gastric endoscopic submucosal dissection without using proton pump inhibitor injection: a propensity score analysis

Purpose: Endoscopic submucosal dissection is a promising method for the resection of superficial gastric neoplasms. To date, several institutions have used proton pump inhibitor injections over the perioperative period. However, there is very little evidence regarding their efficacy. To overcome this limitation, we compared procedural outcomes and the prevention of adverse events of proton pump inhibitor injection with an orally administered active potassium-competitive acid blocker alone. Participants and Methods: We enrolled a total of 150 patients treated for superficial gastric neoplasms at a single institution between April 2015 and December 2018. Patients treated for 2 days with proton pump inhibitor injections following 12 days of oral potassium-competitive acid blocker (proton pump inhibitor group=80) were compared with patients treated for 14 days orally with potassium-competitive acid blocker alone (potassium-competitive acid blocker group=70) using propensity score analysis. We evaluated intragastric pH levels prior to endoscopic submucosal dissection, frequency of intraoperative major bleeding, procedure time, en bloc resection rate, curability, ulcer reduction rate 14 days after endoscopic submucosal dissection, and adverse events (including perforation and postoperative bleeding). Results: Propensity score analysis yielded 43 matched pairs. The comparison demonstrated similar values for the outcomes. For all cases, we observed intragastric pH levels >6.4 prior to endoscopic submucosal dissection. Postoperative bleeding rates were 2.3% (1/43) in the proton pump inhibitor group and 0.0% (0/43) in the potassium-competitive acid blocker group (P=0.315). Conclusions: Oral potassium-competitive acid blocker alone was as effective as proton pump inhibitor injection, with a low incidence of adverse events. Based on these results, proton pump inhibitor injection might be omitted during gastric endoscopic submucosal dissection.

Bleeding after endoscopic submucosal dissection of gastric lesions

Endoscopic submucosal dissection (ESD) is generally used to treat gastric mucosal and submucosal lesions. Nevertheless, ESD is more difficult and complicated to perform than a traditional endoscopic mucosal resection, which can increase the incidence of various complications including hemorrhage, perforation and infection. Hemorrhage is a major post-ESD complication. Prevention and early diagnosis of post-ESD bleeding for gastric lesions are closely associated with the efficacy and safety of the operation. Many studies have reported the risks of and the preventative measures for hemorrhage after gastric ESD, but there remain some issues to be solved. We thus reviewed the risk factors, precautions and treatments for hemorrhage after ESD of gastric lesions.

Utility of autologous fibrin glue and polyglycolic acid sheet for preventing delayed bleeding associated with antithrombotic therapy after gastric ESD

Background and study aims  Delayed bleeding is one of the most serious adverse events of gastric endoscopic submucosal dissection (ESD), especially in patients taking antithrombotic therapy. This study aimed to evaluate the utility and safety of a shielding method with autologous fibrin glue and polyglycolic acid (PGA) sheets for patients undergoing gastric ESD who are receiving antithrombotic therapy. Patients and methods  One hundred twenty-three patients who were treated with gastric ESD while receiving antithrombotic therapy between December 2014 and September 2017 were enrolled in this study. Patients who received the shielding method were classified into the shielding group. Others were classified into the conventional group. Various clinico-pathological factors were retrospectively compared between the two groups. Results  The shielding group consisted of 38 patients, and the conventional group consisted of the remaining 85 patients. In the shielding group, the rate of continuation of antithrombotic therapy was significantly higher (68.4 % vs 41.2 %). Incidence of delayed bleeding was lower in the shielding group (2.6 %, 1/38) than in the conventional group (14.1 %, 12/85). In the propensity score-adjusted logistic regression analysis, the delayed bleeding rate in the shielding group tended to be lower than in the conventional group ( P  = 0.070). Allogeneic transfusion was performed in eight patients (8/85, 9.4 %) in the conventional group and none in the shielding group ( P  = 0.047). No adverse event associated with endoscopic shielding were observed in the shielding group. Conclusions  This study suggests that a shielding method with autologous fibrin glue and PGA sheet effectively prevents delayed bleeding after gastric ESD in patients receiving antithrombotic therapy.

Feasibility of Autologous Fibrin Glue and Polyglycolic Acid Sheets to Prevent Delayed Bleeding after Endoscopic Submucosal Dissection of Gastric Neoplasms in Patients Receiving Antithrombotic Therapy

Background/Aims

Delayed bleeding is one of the most serious complications following gastric endoscopic submucosal dissection (ESD) under antithrombotic therapy. As a safety measure, for patients receiving antithrombotic therapy, we covered the ESD ulcer with autologous fibrin glue (prepared using autologous blood) alone or with polyglycolic acid (PGA) sheets.

Methods

From July 2014 to November 2015, 20 patients with gastric neoplasms who were receiving antithrombotic therapy were enrolled in this study. After ESD, the ESD ulcers were covered with autologous fibrin glue alone or with PGA sheets. We prospectively evaluated the feasibility of this safety measure.

Results

In total, 22 lesions in 20 patients were resected en bloc by ESD. The mean specimen size and tumor size were 31.5 ± 9.5 mm and 14.0 ± 8.8 mm, respectively. There were no cases of delayed bleeding or adverse events in this study. Attachment of autologous fibrin glue was observed in 81.8% (18/22) and 68.2% (15/22) of lesions at endoscopy performed 1 day and 7 days after ESD, respectively.

Conclusion

No patient in this study had delayed bleeding or adverse events. This suggests that this measure may facilitate the safety of gastric ESD in patients receiving antithrombotic therapy. This trial is registered with UMIN000019386.

Is endoscopic ultrasonography useful for endoscopic submucosal dissection?

Endoscopic submucosal dissection (ESD) is an innovative advance in the treatment of early gastrointestinal (GI) cancer without lymph node metastases and precancerous lesions as it is an effective and safe therapeutic method. ESD has also been a promising therapeutic option for removal of submucosal tumors (SMTs) for improving the completeness of resection of a large lesion. Endoscopic ultrasonography (EUS) can be used to detect the depth of invasion during the preoperative evaluation because of its close proximity to the lesion. EUS-guided fine-needle aspiration can be used to increase the diagnostic accuracy of EUS in determining the malignant lymph node. EUS is considered to be a useful imaging procedure to characterize early GI cancer, which is suspicious for submucosal invasion, and the most accurate procedure for detecting and diagnosing SMTs for further treatment. In the process of ESD, EUS can also be used to detect surrounding blood vessels and the degree of fibrosis; this may be helpful for predicting procedure time and decreasing the risk of bleeding and perforation. EUS-guided injection before ESD renders the endoscopic resection safe and accurate. Therefore, EUS plays an important role in the use of ESD. However, compared to conventional endoscopic staging, EUS sometimes can under or overstage the lesion, and the diagnostic accuracy is controversial. In this review, we summarize the latest research findings regarding the role of EUS in ESD.

Factors associated with the outcomes of endoscopic submucosal dissection in pyloric neoplasms

BACKGROUND

Pyloric neoplasms are one of the most technically difficult lesions to remove by endoscopic submucosal dissection (ESD).

OBJECTIVE

To evaluate the therapeutic outcomes of ESD in pyloric neoplasms according to clinicopathologic characteristics and to assess predictive factors for incomplete resection.

DESIGN

A retrospective, single-center study.

PATIENTS

A total of 110 cases of pyloric adenomas and early cancers treated with ESD from January 2007 to May 2013 were included.

INTERVENTION

ESD procedures with or without retroflexion maneuver were used in all qualifying cases.

MAIN OUTCOME MEASUREMENTS

Therapeutic outcomes of ESD and procedure-related adverse events.

RESULTS

Complete resection rates differed significantly in relation to location (pylorus vs pylorus with duodenal extension, 79% vs 58%), directional distribution (upper hemisphere vs lower hemisphere of the pylorus, 67% vs 90%), tumor size (≤ 10 mm vs > 10 mm, 84% vs 67%), and circumferential extent of pyloric mucosal resection (≤ 1/2 vs > 1/2, 92% vs 62%). On multivariate analysis, tumor location (pylorus with duodenal extension; odds ratio 5.747), hemispheric distribution (upper hemisphere; odds ratio 4.906), and circumferential extent of resection (> 1/2; odds ratio 3.960) were independent factors associated with incomplete resection. The rates of procedure-related bleeding, stenosis, and perforation were 8%, 1%, and 1%, respectively; none of the adverse events required surgical intervention.

LIMITATIONS

Single-center, retrospective study.

CONCLUSIONS

ESD is a safe, effective, and feasible treatment for pyloric neoplasms. However, the complete resection rate decreases for tumors that have duodenal extension, are located in the upper hemisphere, and have large circumferential extent of resection.

Submucosal tunneling endoscopic resection of esophageal submucosal tumors originating from the muscularis propria layer: A retrospective analysis

AIM: To evaluate the safety and efficacy of submucosal tunneling endoscopic resection (STER) for esophageal submucosal tumors (SMTs) originating from the muscularis propria layer.

METHODS: Between April 2012 and August 2013, 5 patients with esophageal SMTs originating from the muscularis propria layer were treated by STER. The key steps were as follows: (1) creating a submucosal tunnel to uncover the tumor; (2) resecting the tumor en bloc by endoscopic resection techniques; and (3) closing the mucosal incision site after the tumor was removed.

RESULTS: STER was successfully performed in all 5 cases (success rate: 100%). The mean tumor size was 1.6 cm (range, 1.0-2.5 cm). The mean procedure time was 108.6 min (range, 80-138 min). The average hospital stay was 5.8 d (range, 5-7 d). The mean number of clips used was 7 (5-9). Pathological diagnosis of the tumors was leiomyoma (4/5) and mesenchymal tumor (1/5) with lateral and basal resection margins free of tumor tissue. During the procedure, one patient developed subcutaneous emphysema, who recovered after conservative treatment. No residual or recurrent tumors were detected during the 6-mo (4 patients) and 12-mo (1 patient) follow-up period.

CONCLUSION: STER seems to be a safe and effective procedure for treatment of esophageal SMTs originating from the muscularis propria layer, but its indications need to be further investigated.

Preventing and controlling bleeding in gastric endoscopic submucosal dissection

Although techniques and instruments for endoscopic submucosal dissection (ESD) have improved, bleeding is still the most common complication. Minimizing the occurrence of bleeding is important because blood can interfere with subsequent procedures. Generally, ESD-related bleeding can be divided into intraprocedural and postprocedural bleedings. Postprocedural bleeding can be further classified into early post-ESD bleeding which occurs within 48 hours after ESD and late post-ESD bleeding which occurs later than 48 hours after ESD. A basic principle for avoiding intraprocedural bleeding is to watch for vessels and coagulate them before cutting. Several countertraction devices have been designed to minimize intraprocedural bleeding. Methods for reducing postprocedural bleeding include administration of proton-pump inhibitors or prophylactic coagulation after ESD. Medical adhesive spray such as n-butyl-2-cyanoacrylate is also an option for preventing postprocedural bleeding. Various endoscopic treatment modalities are used for both intraprocedural and postprocedural bleeding. However, hemoclipping is infrequently used during ESD because the clips interfere with subsequent resection. Bleeding that occurs as a result of ESD can usually be managed easily. Nonetheless, more effective ways to prevent bleeding, including reliable ESD techniques, must be developed.

Prospective Study about the Utility of Endoscopic Ultrasound for Predicting the Safety of Endoscopic Submucosal Dissection in Early Gastric Cancer (T-HOPE 0801)

Background. Intraoperative bleeding is an important determinant for safety of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). This study aimed to prospectively evaluate the usefulness of endoscopic ultrasound (EUS) for predicting ESD safety. Methods. A total of 110 patients with EGC were divided into two groups based on EUS findings: group P, almost no blood vessels in submucosa, or ≤4 small vessels per field of view; group R, remaining patients. Primary endpoint was the decrease in Hb after ESD. Secondary endpoints included procedure time and the incidence of muscle injury and clip use. Results. A total of 89 patients were evaluated. Fifty were classified into group P and 39 into group R. Mean decrease in Hb was 0.27 g/dL in group P and 0.35 g/dL in group R, with no significant difference. Mean procedure time was significantly longer in group R (105.4 min) than in group P (65.5 min) (P < 0.001). The incidence of muscle injury and clip use were significantly higher in group R (25.6%/48.7%) than in group P (8.0%/20.0%) (P = 0.02/P = 0.004). Conclusion. Preoperative EUS can predict procedure time and the incidence of muscle injury and clip use and is thus considered useful for predicting gastric ESD safety.

The current state of diagnosis and treatment for early gastric cancer

The prognosis for gastric cancer depends on its stage; so, detection in the early stage of disease is important, when complete and curative removal is possible. Accurate diagnosis can be facilitated by a sound understanding of the basic findings of white light endoscopy of early gastric cancer, and diagnosis can be refined further by the combined use of other imaging modalities such as image-enhanced endoscopy including chromoendoscopy and endoscopic ultrasonography. Minimally invasive endoscopic treatment has come to be the preferred therapeutic approach for early gastric cancer. In addition to conventional endoscopic mucosal resection, a new technique known as endoscopic submucosal dissection (ESD) has spread rapidly worldwide. Indeed, strategies for ESD have been established, devices developed, its indications expanded, and its safety and long-term results extensively reported. Some unique combination therapies involving endoscopy and surgical treatment have also been reported. It is anticipated that the number of patients undergoing endoscopic therapy will continue to increase, and the ongoing developments in endoscopic treatment are expected not only to improve gastric cancer prognosis but also to maintain good quality of life after treatment.

Management of bleeding and artificial gastric ulcers associated with endoscopic submucosal dissection

Endoscopic submucosal dissection (ESD), an endoscopic procedure for the treatment of gastric epithelial neoplasia without lymph node metastases, spread rapidly, primarily in Japan, starting in the late 1990s. ESD enables en bloc resection of lesions that are difficult to resect using conventional endoscopic mucosal resection (EMR). However, in comparison to EMR, ESD requires a high level of endoscopic competence and a longer resection time. Thus, ESD is associated with a higher risk of adverse events, including intraoperative and postoperative bleeding and gastrointestinal perforation. In particular, because of a higher incidence of intraoperative bleeding with mucosal incision and submucosal dissection, which are distinctive endoscopic procedures in ESD, a strategy for endoscopic hemostasis, mainly by thermo-coagulation hemostasis using hemostatic forceps, is important. In addition, because of iatrogenic artificial ulcers that always form after ESD, endoscopic hemostasis and appropriate pharmacotherapy during the healing process are essential.