Usefulness and safety of 0.4% sodium hyaluronate solution as a submucosal fluid "cushion" in endoscopic resection for gastric neoplasms: a prospective multicenter trial

Endoscopic Submucosal Dissection (ESD) in Colorectal Tumors

Background

Endoscopic submucosal dissection (ESD) – initially developed for the treatment of early gastric cancer in Japan – is an attractive option for en bloc resection of larger sessile or flat colorectal neoplasia.

Methods

A review of the current literature on colorectal ESD was carried out.

Results

In contrast to conventional endoscopic mucosal resection (EMR), ESD for larger colorectal neoplasia yields high en bloc resection rates and very low recurrence rates. The frequency of delayed bleeding is similar for EMR and ESD. Higher perforation rates during ESD are mostly due to microperforations identified and treated during the intervention, and are therefore of minor clinical relevance. A major disadvantage of ESD is the necessity for high-level endoscopic skills and long procedure times. ESD also has the potential to replace laparoscopic surgery or transanal endoscopic microsurgery mainly due to its lower complication rates.

Conclusion

ESD for the resection of larger flat or sessile colorectal lesions has potential advantages over conventional EMR or minimally invasive surgery. Due to the low incidence of early gastric cancer, experience with ESD will remain limited in Western countries. The spread of colorectal ESD will depend on adequate training opportunities and also on modifications yielding a reduction in procedure time.

Endoscopic submucosal dissection for gastric tube cancer after esophagectomy

BACKGROUND

Recent improvements in the survival of patients after esophagectomy have led to an increasing occurrence of gastric tube cancer (GTC). Removal of the reconstructed gastric tube, however, can lead to high morbidity and mortality.

OBJECTIVE

To assess the feasibility and effectiveness of endoscopic submucosal dissection (ESD) for GTC.

DESIGN

Retrospective study.

SETTING

National Cancer Center Hospital, Tokyo, Japan.

PATIENTS

We investigated patients with GTC after esophagectomy undergoing ESD from 1998 to 2011.

INTERVENTION ESD MAIN OUTCOME MEASUREMENTS

Patient characteristics, endoscopic findings, technical results, histopathology including curability and Helicobacter pylori gastritis, and long-term outcomes.

RESULTS

There were 51 consecutive patients with 79 lesions including 38 lesions (48%) meeting the absolute indication, 31 (39%) satisfying the expanded indications, and 10 (13%) falling outside such indications. The median procedure time was 90 minutes. There were 73 en bloc resections (92%), 59 en bloc resections with tumor-free margins (R0 resections, 75%), and 51 curative resections (65%) based on the Japanese Gastric Cancer Association criteria. Fifty patients (98%) were assessed as H pylori gastritis positive. Adverse events included 3 perforations (3.8%) during ESD and 2 delayed perforations (2.5%) without any emergency surgery and 3 delayed bleeding (3.8%). Local recurrence was detected in 4 patients (7.8%), and metachronous GTCs were identified in 18 patients (35%). Five patients (10%) died of GTC including 3 metachronous lesions. The 5-year overall survival rate was 68.4%, and the disease-specific survival rate was 86.7% with 100% for curative and 72.7% for non-curative patients during a median follow-up period of 3.8 years (range, 0-12.1 years).

LIMITATION

Single-center retrospective study.

CONCLUSIONS

ESD for GTC was feasible and effective for curative patients; however, long-term outcomes for non-curative patients were less satisfactory.

High-pressure jet injection of viscous solutions for endoscopic submucosal dissection: a study on ex vivo pig stomachs

BACKGROUND

Long-lasting lifting is a key factor during endoscopic submucosal dissection (ESD) and can be obtained by water-jet injection of saline solution or by injection of viscous macromolecular solutions. Combination of the jet injection and the macromolecular viscous solutions has never been used yet. We assessed the ability of a new water-jet system to inject viscous solutions in direct viewing and in retroflexion. We compared jet injection of saline solution and hyaluronate 0.5 % to perform ESD on ex vivo pig stomachs in order to evaluate the benefits of macromolecular solutions when injected by a jet-injector system.

METHODS

This is a prospective comparative study in pig stomachs. Using the jet injector, four viscous solutions were tested: hydroxyethyl starch, glycerol mix, hyaluronate sodic (0.5 %), and poloxamer mix. Ten ESDs larger than 25 mm (five in direct viewing and five in retroflexion) and one larger than 10 cm were performed with each solution. ESD with hyaluronate jet injection was then compared with ESD with saline jet injection by performing 50 ESDs in each group. A single, minimally-experienced operator conducted all the procedures.

RESULTS

All 145 resections were complete, including all marking points with two perforations. Eleven jet ESDs per solution were conducted without any injection issue. In the second part of the study, when compared with saline, significant benefit of hyaluronate was observed on dissection speed (0.80 vs. 1.08 cm(2)/min, p < 0.001).

CONCLUSION

This is the first report on a jet-injector system allowing injection of macromolecular viscous solutions even with retroflexed endoscope. Jet injection of macromolecular solutions can speed up dissection in comparison with saline, and should now be tested on humans.

Endoscopic submucosal dissection for early gastric cancer in the remnant stomach after gastrectomy

BACKGROUND

Endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) after surgical gastrectomy is a technically difficult procedure because of the limited working space in the remnant stomach as well as the presence of severe gastric fibrosis and staples under the suture line.

OBJECTIVE

We evaluated clinical results including long-term outcomes to determine the feasibility and effectiveness of ESD for EGC in the remnant stomach of patients after gastrectomy.

DESIGN

Retrospective study.

SETTING

National Cancer Center Hospital, Tokyo, Japan.

PATIENTS

We investigated patients undergoing ESD for EGC in the remnant stomach from 1997 to 2011.

INTERVENTION ESD MAIN OUTCOME MEASUREMENTS

We examined the patient characteristics, endoscopic findings, technical results, adverse events, and histopathologic results including curability and evaluations of Helicobacter pylori gastritis in addition to the rates of local recurrence, metachronous gastric cancer, overall survival, and cause-specific survival.

RESULTS

A total of 128 consecutive patients with 139 lesions had previously undergone 87 distal (68%), 25 proximal (19.5%) and 16 pylorus-preserving gastrectomies (12.5%). The median period from the original gastrectomy to the subsequent ESD for EGC in the remnant stomach was 5.7 years (range 0.6-51 years), the median tumor size was 13 mm (range 1-60 mm), and the median procedure time was 60 minutes (range 15-310 minutes). There were 131 en bloc resections (94%), with curative resections achieved for 109 lesions (78%); 22 lesions (16%) resulted in non-curative resections, and 8 lesions (6%) had only a horizontal margin positive or had inconclusive results. A total of 118 patients (92%) were assessed as H pylori gastritis-positive, with 7 patients (5%) negative. Adverse events included 2 cases of delayed bleeding (1.4%) and 2 perforations (1.4%), with 1 patient requiring emergency surgery. The 5-year overall and cause-specific survival rates were 87.3% and 100%, respectively, during a median follow-up period of 4.5 years (range 0-13.7 years), with no deaths from EGC in the remnant stomach.

LIMITATIONS

Single-center, retrospective study.

CONCLUSION

ESD for EGC in the remnant stomach of patients after gastrectomy was a feasible and effective therapeutic method and should become the standard treatment in such cases, based on the favorable long-term outcomes.

Creation of simulated papillae for endoscopic sphincterotomy and papillectomy training by using in vivo and ex vivo pig model (with videos)

BACKGROUND

There are few in vivo and ex vivo models for training in endoscopic sphincterotomy (ES) and endoscopic papillectomy (EP).

OBJECTIVE

We describe in vivo and ex vivo training pig models that use a simulated papilla for hands-on teaching of ES and EP.

DESIGN

Animal experiment.

SETTING

A referral center.

MATERIALS AND INTERVENTIONS

Hyaluronate solution (0.4%) was injected submucosally using a 25-gauge sclerotherapy needle to create a submucosal bleb by using porcine in vivo stomach, ex vivo stomach, and ex vivo rectum. ES and EP were then performed by using a pull-type sphincterotome and snare, respectively.

MAIN OUTCOME MEASUREMENT

The feasibility of creating a simulated papilla for ES and EP procedures was tested by experienced and nonexperienced ERCP endoscopists.

RESULTS

Creation of a hemispheroidal bulge was successful in 13 of 17 (76%) areas within an in vivo stomach, 13 of 16 (81%) areas of an ex vivo stomach, and 16 of 16 (100%) areas in an ex vivo rectum. In the in vivo stomach model, ES was successfully and realistically performed on the anterior wall of the stomach rather than in other walls. In the ex vivo stomach model, endoscopists experienced in ERCP and trainees performed ES without difficulty, whereas it was difficult or impossible for nonexperienced trainees to perform ES. In the ex vivo rectum model, all 3 endoscopists were able to complete not only ES but also EP.

LIMITATIONS

Pilot study.

CONCLUSIONS

Although further studies are necessary to evaluate the reproducibility and cost-effectiveness, this novel pig model appears useful for ES and EP training.

Early gastric cancer and dysplasia

Since the concept of early gastric cancer was first described in Japan in 1962, its treatment has evolved from curative surgical resection to endoscopic resection, initially with polypectomy to more recently with endoscopic submucosal dissection. As worldwide experience with these endoscopic techniques evolve and gain acceptance, studies have confirmed its comparable effectiveness with historical surgical outcomes in carefully selected patients. The criteria for endoscopic resection have expanded to offer more patients improved quality of life, avoiding the morbidity and mortality associated with surgery. This article summarizes the evolutional role of endoscopic and surgical therapy in early gastric cancer.

Usefulness of sodium hyaluronate solution in colorectal endoscopic mucosal resection

BACKGROUND

In endoscopic mucosal resection (EMR), it is essential to inject submucosal fluid to prevent complications and ensure safe and complete en bloc resection of tumors. Sodium hyaluronate (SH) solution, which is effective in forming and maintaining a mucosal lift and is innocuous to mucosal tissue, is considered a useful injection solution for endoscopic submucosal dissection, a procedure associated with a high risk of perforation. This study was undertaken to assess the usefulness of this solution in EMR.

METHODS

Ninety-four patients with colorectal tumors of ≤20 mm in diameter were enrolled for this study and randomized to a SH solution group (0.2% two-fold diluted MucoUp) or to a normal saline group (control). Ease of EMR was primarily assessed based on ease of submucosal injection, ease of snaring and injection time.

RESULTS

SH solution was superior to normal saline for ease of submucosal injection (57 ± 0.7 vs 50 ± 0.7; P < 0.05), and it showed better results for ease of snaring with less variability (63 ± 0.8 vs 51 ± 1.0; P < 0.05). The mean injection time was similar between the two groups (3.0 ± 9.0 s and 3.0 ± 2.7 s, respectively). Post-procedural hemorrhage occurred in 7% patients (3/46) injected with SH solution and in 6% of patients (3/48) in the control group; there was no significant difference between the groups.

CONCLUSIONS

Use of two-fold diluted MucoUp facilitated colorectal EMR.

Endoscopic submucosal dissection--current success and future directions

More than 10 years have passed since endoscopic submucosal dissection (ESD) was first developed in Japan. ESD enables en bloc complete resection of superficial gastrointestinal neoplasms regardless of the size and location of the lesions. With improvements in techniques and devices, excellent therapeutic results have been achieved despite the inherent technical difficulties of this procedure. ESD aiming for curative treatment can be performed for gastrointestinal neoplasms without risk of lymph node metastasis. Accurate histopathologic examination of the resected specimen is required to determine the risk of lymph node metastasis, for which en bloc resection is beneficial. Owing to the high success rate of en bloc complete resection and accurate histopathologic examination, tumour recurrence rates after ESD are reported to be very low in Japan. Excellent results of ESD in a large number of cases have also been reported from other Asian countries such as South Korea, Taiwan and China. Although scepticism exists among Western clinicians regarding the application of ESD, it is developing slowly and reports indicate promising results in some European countries. With further development of technologies, such as endoscopic robotics, ESD could become the worldwide treatment of choice for early gastrointestinal neoplasms.

Supportive techniques and devices for endoscopic submucosal dissection of gastric cancer

The indications for endoscopic treatment have expanded in recent years, and relatively intestinal-type mucosal stomach carcinomas with a low potential for metastasis are now often resected en bloc by endoscopic submucosal dissection (ESD), even if they measure over 20 mm in size. However, ESD requires complex maneuvers, which entails a long operation time, and is often accompanied by complications such as bleeding and perforation. Many technical developments have been implemented to overcome these complications. The scope, cutting device, hemostasis device, and other supportive devices have been improved. However, even with these innovations, ESD remains a potentially complex procedure. One of the major difficulties is poor visualization of the submucosal layer resulting from the poor countertraction afforded during submucosal dissection. Recently, countertraction devices have been developed. In this paper, we introduce countertraction techniques and devices mainly for gastric cancer.

Endoscopic submucosal dissection of early gastric neoplasia with a water jet-assisted knife: a Western, single-center experience

BACKGROUND

Endoscopic submucosal dissection (ESD) of early gastric neoplasia has not yet been established in Western countries because of a lack of data and the difficult, time-consuming, and hazardous nature of the method. Some of the technical limitations may be overcome by use of a water jet-assisted knife, which allows a combination of a high-pressure water jet and electrosurgical interventions.

OBJECTIVE

To evaluate the efficacy and safety of water jet-assisted ESD (WESD) with a water jet-assisted knife in selected patients with early gastric neoplasia.

DESIGN

Single-center, prospective study.

PATIENTS

This study involved 29 consecutive patients (13 female; median age 61 years; age range 35-93 years) with early gastric neoplasia that met the expanded criteria of the Japanese Gastric Cancer Association. Histology of biopsies had shown gastric adenocarcinoma in 21 cases, adenoma in 8 case, and suspicion of a GI stromal tumor in 1 case. The median maximal diameter of the lesions was 20 mm (range 10-40 mm).

INTERVENTION

All procedures were done with patients under sedation with propofol. The water jet-assisted knife was used for setting coagulation markers around the neoplastic lesions, then for circumferential incision and dissection in combination with repeated submucosal injection of saline solution with a water jet system. Bleeding was treated with diathermia by use of the water jet-assisted knife or hemostatic forceps in case of failure or larger vessels. Clips were used for closure of perforations.

MAIN OUTCOME MEASUREMENTS

Complete resection of neoplasia, procedure time, complication and recurrence rates.

RESULTS

According to endoscopic criteria, complete resection of the targeted area could be achieved in all cases, with an en bloc resection rate of 90%. The median procedure duration was 74 minutes (range 15-402 minutes). Exchange of the device was needed in only 10 cases because of severe bleeding from larger vessels, which could be managed by use of hemostatic forceps. The 30-day morbidity rate was 4 of 30 (13.8%) because of postprocedure pain in 3 cases and delayed bleeding in 1 case. A 93-year-old patient died the night after WESD without evidence of a procedure-related complication. Histology of the resected specimens showed adenocarcinoma in 20 cases, adenoma in 7, no neoplasia in 2, and a plasmacytoma in 1. Complete resection (R0) was histologically confirmed in 18 of 28 patients (64.3%) with resected neoplastic specimens. A horizontal or vertical neoplasia-free margin could not be confirmed in 9 cases and 1 case, respectively. Complete local remission of neoplasia was achieved in 25 of 28 patients (89.3%) who were followed over a median period of 22 months (range 6-44 months). In 1 patient, a metachronous gastric adenocarcinoma was identified 54 weeks after initial WESD.

LIMITATIONS

Noncontrolled study with a limited number of patients.

CONCLUSION

The use of a water jet-assisted knife simplifies ESD because exchange of devices is rarely needed. WESD promises to be effective and safe. The study demonstrates that the high rates of en bloc resection of early gastric neoplasia reported in Asia can be reproduced in Western referral centers. However, histology may not always confirm complete resection of horizontal tumor margins. In spite of the unfavorable histology results, the high rate of complete local remission of neoplasia promises that surgical treatment of early gastric neoplasia can be avoided in the majority of cases.

Endoscopic mucosal resection with an over-the-counter hyaluronate preparation

BACKGROUND

Hyaluronic acid (HA) provides a long-lasting and distinct mucosal elevation for EMR, but expense and inconvenience have limited its adoption.

OBJECTIVE

To evaluate the safety and efficacy of an over-the-counter 0.15% HA preparation for EMR.

DESIGN

Retrospective study.

SETTING

Veterans Administration Hospital and university hospital.

PATIENTS

30 patients with a total of 32 colonic lesions and 1 duodenal lesion.

INTERVENTION

EMR by using HA.

MAIN OUTCOME MEASUREMENTS

En bloc resection rate and complications.

RESULTS

EMR was successful in all cases. En bloc resection was achieved in 26 of the 28 lesions up to 25 mm in diameter. Two lesions, both with fibrosis from prior attempted resection, had trace residual tissue necessitating cauterization with argon plasma. Five lesions measuring 30 mm to 60 mm all required piecemeal resection. There was one complication, a postpolypectomy bleed.

LIMITATIONS

Small number of patients and retrospective design.

CONCLUSIONS

EMR may be performed safely and effectively by using an inexpensive, over-the-counter 0.15% HA preparation. Further studies are needed to verify the results of this study and to compare the safety and efficacy of this HA preparation with saline solution.

Endoscopic full-thickness resection of a lateral spreading rectal tumor after unplanned injection of dilute hyaluronic acid into the subserosal layer (with video)

A 74-year-old woman underwent colonoscopy for investigation of a liver tumor. A lateral spreading tumor of the non-granular type (LST-NG), 25 mm in diameter, was detected at the rectosigmoid junction. As magnifying image-enhanced colonoscopy suggested a tubulovillous adenoma, endoscopic mucosal resection (EMR) was chosen for removal of the LST-NG. The lesion was effectively and evenly lifted after injection of 0.4% hyaluronic acid diluted with glycerol in the ratio of 1:1. A small amount of indigo-carmine dye was also added for coloration of the plane of resection. The lesion was completely removed en bloc. Although a blue-colored layer was identified in the resection defect, a small amount of a whitish layer was detected above the blue layer. The muscle layer was clearly located on the underside of the resected polyp. A total of 14 endoclips were used to close the defect completely. The patient was successfully treated conservatively without surgery. Histology of the resected specimen showed that it contained a tubulovillous adenoma with the submucosal layer and both layers of the muscularis propria. The surgical margin was free of neoplastic change horizontally and vertically. To the best of our knowledge, this is the first case report of full-thickness resection associated with EMR after unplanned injection of dilute hyaluronic acid into the subserosal layer rather than the intended submucosal layer. We describe how to promptly recognize this complication during colonoscopy, in order to achieve immediate closure of the defect, with the identification of a "mirror target sign" on the colonic wall.

Sodium alginate as an ideal submucosal injection material for endoscopic submucosal resection: preliminary experimental and clinical study

BACKGROUND

Sodium alginate is used clinically in the treatment of peptic ulcer disease. Because of its viscosity, sodium alginate could possibly become a new submucosal injection material for use in endoscopic resection.

OBJECTIVE

We evaluated the feasibility of endoscopic submucosal dissection (ESD) using sodium alginate.

SETTING AND INTERVENTIONS

The lesion-lifting properties of sodium alginate were examined in porcine stomachs and were compared with those of normal saline solution and sodium hyaluronate solution. After confirming the proper concentration of sodium alginate, ESD using sodium alginate was performed in 11 patients with gastric mucosal cancer or adenoma.

MAIN OUTCOME MEASUREMENT

The lesion-lifting properties of sodium alginate and clinical outcomes were assessed.

RESULTS

The thickness of the submucosal elevation created by 3% sodium alginate in porcine stomach was equivalent to that of sodium hyaluronate. ESD using sodium alginate was completed successfully in all patients without adverse effects except in 1 patient in whom transient shrinkage of the gastric wall disappeared spontaneously after approximately 30 minutes. The mean tumor size was 15.3 mm. En bloc resection and a negative resection margin were obtained in all. Histopathologic examination revealed that all tumors were confined to the mucosal layer except for 1 that was confined to the submucosal layer without lymphovascular invasion, and there were no adverse effects such as tissue damage. No patient required additional treatment, and none showed recurrence during a median follow-up period of 28 months.

LIMITATIONS

Small sample size.

CONCLUSION

This preliminary study suggests that sodium alginate might be a novel, safe submucosal injection material for use in endoscopic resection. Further investigation of the properties of sodium alginate is warranted.

Feasibility of endoscopic submucosal dissection: a new technique for en bloc resection of a large superficial tumor in the colon and rectum

Endoscopic submucosal dissection (ESD) is a promising procedure that enables en bloc resection of large superficial tumors in the upper gastrointestinal tract. On the other hand, ESD in the colon and rectum is technically difficult to perform because of its anatomical features. At our institution, 137 consecutive superficial colorectal tumors larger than 20 mm in diameter in 137 patients were treated by ESD between April 2007 and October 2010, and 132 lesions were successfully resected. The average procedure time was 79.2 minutes, and the rate of en bloc resection was 89.1% (122/137). The rate of complete resection, defined as en bloc resection with tumor-free lateral and vertical margins, was 85.4% (117/137). The rate of perforation was 3.6% (5/137). Colorectal ESD achieved a high rate of en bloc resection and complete resection and is applicable in the colorectum.

Efficacy of hyaluronic acid in endoscopic mucosal resection of colorectal tumors

BACKGROUND AND AIM

Endoscopic mucosal resection (EMR) is the standard procedure for colorectal tumors. High mucosal elevation by submucosal injection is important for definite en bloc resection and the prevention of perforation. Hyaluronic acid (HA) is a reportedly useful injection solution for high and long-lasting mucosal elevation, but the ideal HA concentration for optimization of mucosal elevation maintenance, injection pressure, and cost is unknown. In the present study, we assessed the appropriate concentration of HA for EMR.

METHODS

A resected porcine colon and esophagus were used. The injection solutions examined were 0.9% normal saline (NS) and four concentrations of an 800-KDa HA preparation (0.4%, 0.2%, 0.13%, and 0.1%). Each solution (2 mL) was injected into the submucosa; injection pressure was calculated, and elevation was measured. The durations of mucosal elevation and EMR were additionally assessed in the living minipig colon.

RESULTS

In the resected porcine colon, the mucosal elevation was measured 0, 2, 4, and 6 min after the submucosal injection. All concentrations of HA solution maintained greater mucosal elevation at all times than NS (P < 0.05). An almost similar result was obtained in the resected porcine esophagus. The injection pressure correlated with the HA concentration. In the living minipig colon, mucosal elevation diminished 2 min after the submucosal injection with NS, but was maintained 2 min after injection with 0.4%, 0.2%, and 0.13% HA. The average duration of EMR was 139 s.

CONCLUSIONS

Mucosal elevation by HA was greater than that by NS in resected and living animal models. We recommend 0.13% HA for maintaining mucosal elevation, injection pressure, and cost.

Carbon dioxide submucosal injection cushion: an innovative technique in endoscopic submucosal dissection

AIM

Endoscopic submucosal dissection (ESD) can successfully resect large lesions en bloc, but it requires a satisfactory submucosal (sm) injection agent for proper safety and efficacy. The aim of the present study was to evaluate the effectiveness of carbon dioxide (CO(2) ) as an ESD sm injection agent.

METHODS

In vitro study using porcine stomachs compared CO(2) with normal saline (NS) and sodium hyaluronic acid (SHA) solution, both of which are currently used to provide long-lasting sm elevation during ESD. Histopathological examination assessed differences between CO(2) and NS sm cushions. ESD were then carried out in vivo in the stomach and rectum of a live pig using CO(2) sm injection.

RESULTS

CO(2) sm elevation was significantly longer lasting than either NS or SHA (P<0.001). Histopathology revealed no mucosal layer tissue damage, and dissection of honeycomb-like fibrous connective tissue in the CO(2) sm cushion. Creating and maintaining a CO(2) sm cushion of sufficient elevation combined with partial physical dissection of the sm layer was achieved, followed by complete endoscopic dissection of the sm layer with all ESD, resulting in successful en-bloc resections having a mean specimen size of 24.3mm within 15min.

CONCLUSION

Safety and efficacy of CO(2) as a satisfactory sm injection agent during ESD was successfully demonstrated in these preliminary studies, warranting further investigation of this innovative technique.

Endoscopic submucosal dissection for residual/locally recurrent lesions after endoscopic therapy for colorectal tumors

BACKGROUND AND STUDY AIM

Residual or locally recurrent lesions may occur after endoscopic therapy for epithelial colorectal tumors. Additional endoscopic mucosal resection is difficult for large lesions. Endoscopic submucosal dissection may be useful for such lesions, but may be more technically difficult for residual/locally recurrent lesions than for primary lesions. This study evaluated the efficacy of endoscopic submucosal dissection for residual/locally recurrent lesions in comparison with primary lesions.

METHOD

This retrospective case-control investigated 34 residual/locally recurrent lesions and 384 primary lesions treated using endoscopic submucosal dissection. Tumor size, resected specimen size, procedure duration, en bloc resection rate, curative resection rate, histology, associated complications, and recurrence rate were compared between groups.

RESULTS

Procedure duration tended to be longer (85 ± 53 min vs 73 ± 55 min) and tumors were significantly smaller (20 ± 13 mm vs 33 ± 20 mm; P < 0.001) in the residual/locally recurrent group, compared with primary lesions. Both groups showed similar percentages of en bloc (100% vs 97.4%) and curative resection (88.4% vs. 83.6%). Perforation rate was significantly higher in the residual/locally recurrent group (14.7% vs 4.4%, P < 0.05). However, emergency surgery was only needed in 1 of 5 cases in the residual/locally recurrent group, with the remaining 4 cases conservatively managed using endoclips.

CONCLUSIONS

Endoscopic submucosal dissection for residual/locally recurrent lesions was curative and efficacy. This procedure could help to avoid surgical resection and frequent follow-up examinations in many patients.

Submucosal injection of 0.4% hydroxypropyl methylcellulose facilitates endoscopic mucosal resection of early gastrointestinal tumors

BACKGROUND AND AIMS

Submucosal injection of a viscoelastic solution prolongs submucosal lift, thus, facilitating endoscopic mucosal resection. Our objective was to assess the safety and clinical effectiveness of 0.4% hydroxypropyl methylcellulose (HPMC) as a submucosal injectant for endoscopic mucosal resection.

PATIENTS AND METHODS

A prospective, open-label, multicenter, phase 2 study was conducted at 2 academic institutions in Brazil. Eligible participants included patients with early gastrointestinal tumors larger than 10 mm. Outcomes evaluated included complete resection rates, volume of HPMC injected, duration of the submucosal cushion as assessed visually, histology of the resected leisons, and complication rates.

RESULTS

Over a 12-month period, 36 eligible patients with superficial neoplastic lesions (stomach 14, colon 11, rectum 5, esophagus 3, duodenum 3) were prospectively enrolled in the study. The mean size of the resected specimen was 20.4 mm (10 to 60 mm). The mean volume of 0.4% HPMC injected was 10.7 mL (range 4 to 35 mL). The mean duration of the submucosal fluid cushion was 27 minutes (range 9 to 70 min). Complete resection was successfully completed in 89%. Five patients (14%) developed immediate bleeding requiring endoclip and APC application. Esophageal perforation occurred in 1 patient requiring surgical intervention. There were no local or systemic adverse events related to HPMC use over the follow-up period (mean 2.2 mo).

CONCLUSION

HPMC solution (0.4%) provides an effective submucosal fluid cushion and is safe for endoscopic resection of early gastrointestinal neoplastic lesions.

Our perspective on endoscopic resection for colorectal neoplasms

Endoscopic mucosal resection (EMR) is a minimally invasive technique for effective treatment of early stage colorectal lesions with no invasive potential. However, the high frequency of local recurrence after piecemeal EMR for large lesions is considered a serious problem. In contrast, endoscopic submucosal dissection (ESD) allows en-bloc resection, irrespective of the lesion's size. ESD has been established as a standard method for the endoscopic removal of early cancers in the upper gastrointestinal tract in Japan. Although the use of ESD for colorectal lesions has been studied clinically, ESD is not yet established as a standard therapeutic method. We define the indications for en-bloc resection, based on extensive clinicopathological analyses, as a laterally spreading tumor (LST) non-granular type (LST-NG) lesion greater than 20 mm and an LST granular (LST-G) type lesion greater than 40 mm. Both of these lesions had a high submucosal invasion rate. Especially, LST-NG type lesions greater than 20 mm are technically difficult to remove completely even by piecemeal EMR and are considered a "definite indication for en-bloc resection". The ESD procedure is undoubtedly an ideal method to achieve en-bloc resection, however, the prevalences of suitable lesions among all neoplastic lesions and among all early cancers were not high (1.0% and 5.0%, respectively). Therefore, it is crucial to master more fundamental therapeutic techniques and have knowledge of surveillance strategy after endoscopic treatment.

Comparative performance of novel solutions for submucosal injection in porcine stomachs: An ex vivo study

BACKGROUND

Submucosal injection of normal saline (NS) is commonly used during endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) but is quickly absorbed. Sodium hyaluronate (SH) produces longer lasting mucosal elevation but is expensive.

AIMS

To evaluate the performance of novel solutions for submucosal injection in comparison with NS and SH.

METHODS

One ml of the following solutions was injected in the submucosa of fresh specimens of porcine stomachs: NaCl 0.9%, SH 0.4%, human albumin 25%, two artificial tears solutions, namely, hydroxypropyl methylcellulose (HPMC) 0.3%/dextran 70.1% and polyvinyl alcohol (PVA) 1.4%, hydroxyethyl starch (HES) 6% and polyethylene glycol (PEG) 50%. The time until the disappearance of the mucosal elevation was recorded in a blind manner.

RESULTS

The median duration of mucosal elevation was significantly longer with HPMC/dextran, PVA, HES, PEG and SH (29, 26, 38, 31.5, and 41.5min, respectively) compared with NS (12min) (p<0.05 for each comparison). There were no significant time differences between SH and HPMC/dextran, HES and PEG (p>0.05).

CONCLUSIONS

Novel viscous or hypertonic solutions for submucosal injection, perform better than normal saline and equally well as sodium hyaluronate in porcine stomachs in vitro.

A second-look endoscopy after endoscopic submucosal dissection for gastric epithelial neoplasm may be unnecessary: a retrospective analysis of postendoscopic submucosal dissection bleeding

BACKGROUND

Endoscopic submucosal dissection (ESD) is one of the curative endoluminal surgical procedures for gastric epithelial neoplasms. There has been little research on bleeding after gastric ESD.

OBJECTIVE

To investigate cases of post-ESD bleeding and to verify whether a second-look endoscopy after ESD is effective in the prevention of delayed bleeding.

DESIGN

A retrospective study with consecutive data.

SETTING

A single tertiary referral center.

SUBJECTS

A total of 454 gastric epithelial neoplasms (386 early gastric cancers and 68 gastric adenomas).

INTERVENTIONS

ESD and second-look endoscopy.

MAIN OUTCOME MEASUREMENTS

Predictors on post-ESD bleeding by univariate analysis, incidence of post-ESD bleedings, and the timing of those before and after second-look endoscopy.

RESULTS

Post-ESD bleeding occurred in 26 (5.7%) lesions. Gross type (flat or depressed type) was the only factor influencing post-ESD bleeding. All cases of post-ESD bleeding occurred within 14 days after ESD (median 2; range 0-14), and bleeding tended to occur from the lower and upper stomach earlier and later, respectively. In 19 lesions with delayed bleeding more than 24 hours after ESD, the maximum delayed bleeding rates before and after the second-look endoscopy were 2.8% and 2.5%, respectively.

LIMITATIONS

A retrospective, single-center analysis.

CONCLUSIONS

A second-look endoscopy after gastric ESD may contribute little to the prevention of delayed bleeding.

Endoscopic submucosal dissection with a combination of small-caliber-tip transparent hood and flex knife for large superficial colorectal neoplasias including ileocecal lesions

BACKGROUND

Large superficial neoplasias of the ileocecal region pose an increased degree of complexity for endoscopic resection. This study aimed to evaluate the safety and efficacy of endoscopic submucosal dissection (ESD) for large superficial colorectal neoplasias including ileocecal lesions.

METHODS

A total of 33 superficial colorectal neoplasias, including eight neoplasias in the ileocecal region, were treated with ESD from December 2005 to April 2009. Therapeutic efficacy, complications, and follow-up results were retrospectively evaluated among three groups: ileocecal region, colon, and rectum.

RESULTS

The mean size of all resected neoplasias was 35 +/- 15 mm (range, 20-80 mm) and that of all resected specimens was 41 +/- 15 mm (range, 23-82 mm). The mean procedural time was 121 +/- 90 min (range, 22-420 min). The difference in mean values among the three groups was not significant. The overall rate of en bloc resection was 91% (30/33). Histopathologically, both the lateral and vertical margins in the specimens resected en bloc tested negative (30/30). The rate for en bloc resection in the ileocecal region did not differ significantly from that for the other two groups (p = 0.20 compared with the rate for the colon and p = 0.12 compared with the rate for the rectum). Complications such as perforation and postoperative bleeding did not occur in the ileocecal group. No recurrence was observed in any cases during the mean follow-up period of 20 +/- 12 months (range, 4-44 months).

CONCLUSIONS

The ESD approach is safe and effective for treating large superficial neoplasias of the ileocecal region such as other colorectal neoplasias.

Safety of carbon dioxide insufflation for upper gastrointestinal tract endoscopic treatment of patients under deep sedation

BACKGROUND

It is well known that carbon dioxide (CO(2)) is absorbed faster in the body than air and also that it is rapidly excreted through respiration. This study aimed to investigate the safety of CO(2) insufflation used for esophageal and gastric endoscopic submucosal dissection (ESD) in patients under deep sedation.

METHODS

Patients with either early gastric or esophageal cancers that could be resected by ESD were enrolled in this study from March 2007 to July 2008 and randomly assigned to undergo ESD procedures with CO(2) insufflation (CO(2) group) or air insufflation (air group). A TOSCA measurement system and TOSCA 500 monitor were used to measure and monitor both transcutaneous partial pressure of CO(2) (PtcCO(2)) and oxygen saturation (SpO(2)).

RESULTS

The study enrolled 89 patients and randomly assigned them to a CO(2) group (45 patients) or an air group (44 patients). The mean CO(2) group versus air group measurements were as follows: PtcCO(2) (49.1 +/- 5.0 vs. 50.1 +/- 5.3 mmHg; nonsignificant difference [NS]), maximum PtcCO(2) (55.1 +/- 6.5 vs. 56.8 +/- 7.0 mmHg; NS), PtcCO(2) elevation (9.1 +/- 5.4 vs. 11.4 +/- 5.6 mmHg; p = 0.054), SpO(2) (99.0 +/- 0.7% vs. 99.0 +/- 1.0%; NS), minimum SpO(2) (96.5 +/- 2.4% vs. 95.4 +/- 3.3%; p = 0.085), and SpO(2) depression (2.4 +/- 2.3% vs. 3.3 +/- 2.9%; NS). The PtcCO(2) and SpO(2) measurements were similar in the two groups, but the CO(2) group was better than the air group in PtcCO(2) elevation and minimum SpO(2).

CONCLUSIONS

The findings demonstrated CO(2) insufflation to be as safe as air insufflation for upper gastrointestinal tract ESDs performed for patients under deep sedation without evidencing any adverse effects.

A laterally-spreading tumor in a colonic interposition treated by endoscopic submucosal dissection

Herein we describe an early colonic carcinoma which developed in a colonic interposition 14 years after surgery for esophageal cancer, which was successfully treated by endoscopic submucosal dissection (ESD). An 80-year-old man underwent colonic interposition between the upper esophagus and stomach after surgery for an early esophageal squamous cell carcinoma in 1994. He received a surveillance endoscopy, and a laterally-spreading tumor of granular type, approximately 20 mm in size, was identified in the colonic interposition. An endoscopic biopsy revealed moderately differentiated adenocarcinoma histologically, however, we diagnosed the lesion as an intramucosal carcinoma based on the endoscopic findings. The lesion was safely and completely removed en bloc by ESD using a bipolar knife. Histologically, the lesion was an intramucosal moderately differentiated adenocarcinoma in a tubular adenoma.

Endoscopic submucosal dissection and preoperative assessment with endoscopic ultrasonography for the treatment of rectal carcinoid tumors

BACKGROUND

Rectal carcinoid tumors 10 mm in diameter or smaller located within the submucosal layer can be cured by local excision including endoscopic treatment. But complete resection of these tumors with endoscopic polypectomy is difficult. This study aimed to evaluate the usefulness of endoscopic submucosal dissection (ESD) and endoscopic ultrasonography (EUS) for the treatment of rectal carcinoid tumors.

METHODS

In this study, 22 rectal carcinoid tumors in 21 patients were evaluated with EUS and treated using ESD from January 2004 to December 2008.

RESULTS

The mean size of the resected tumors was 6.1 mm (range, 2.0-10 mm) on histopathologic evaluations. When the sizes of the tumors shown by EUS and histopathologic evaluation were compared, the mean values were not significantly different. All the tumors were located within the submucosal layer, and the accuracy of the preoperative depth determination with EUS was 100% (22/22). The mean duration of the ESD procedure was 37 min (range, 20-71 min). The overall rate of en bloc resection with ESD was 100% (22/22). Although postoperative bleeding occurred in two cases (9%), both cases were successfully managed by endoscopic hemostasis. No perforation or recurrence was observed during the mean follow-up period of 30 months (range, 7-66 months).

CONCLUSIONS

Endoscopic submucosal dissection and preoperative assessment with EUS are effective for treating rectal carcinoid tumors and enabling en bloc resection.

Subserosal injection of hyaluronic acid may prevent perforation after endoscopic resection

AIM: To investigate the protective effect of subserosal injection of hyaluronic acid (HA) after endoscopic resection (ER) using ex vivo and in vivo studies.

METHODS: As the first examination, technical application of subserosal injection was tested 10 times using resected porcine stomachs. As the second examination, ER was applied to make six mucosal defects per stomach in three live minipigs and thermal damage was given on the proper muscle layer by using hemostatic forceps. Following the thermocoagulation, 1 mL of normal saline and HA, respectively, was injected targeting the subserosal layer in two mucosal defects each and the rest kept no injection as the control. The minipigs were recovered from the anesthesia and kept fasting until euthanasia which was carried out around 24 h after the procedures.

RESULTS: Ex vivo study revealed that complete and partial subserosal injection was possible two (20%) and four (40%) times, respectively. In vivo study revealed that no postoperative perforation occurred at any point of the thermocoagulation. Apparent retention of hyaluronic acid was identified at only two (33%) points where HA was injected.

CONCLUSION: This study failed to show preventative effects of subserosal injection of HA on postoperative perforation due to technical faults. However, this concept has a possibility to change strategy of ER with further technical innovation.

Endoscopic submucosal dissection in the upper gastrointestinal tract: present and future view of Europe

In Western countries endoscopic mucosal resection (EMR) has been widely accepted for treatment of early Barrett;s neoplasia and flat or depressed colorectal adenomas. In contrast endoscopic submucosal dissection (ESD) is infrequently performed for several reasons. It seems to be difficult to overcome the learning curve of this difficult technique because of the low case volume of early gastric cancer. On the other hand ESD of esophageal or colorectal lesions is even more challenging and is considered to be inappropriate for learning. In addition the indication for esophageal or colorectal ESD is controversial in view of excellent results of the well established EMR technique which is less time-consuming and safer than ESD. A recent survey of leading Western endoscopy centers indicated the limited experience with ESD with a low number of cases for all potential indications. Only a few training courses have been established and the number of ongoing clinical studies is limited. Only 12 out of 340 published articles on "endoscopic mucosal dissection" were reported from Western countries. A better acceptance of ESD requires improvement of the technique to allow an easier, faster and safer approach. There is a strong demand for structured training courses and limitations of human cases to selected centers which participate in prospective trials. A close collaboration between Western and Asian centers is recommended for improvement of the ESD technique and its clinical application.

Usefulness and safety of 0.4% sodium hyaluronate solution as a submucosal fluid "cushion" for endoscopic resection of colorectal mucosal neoplasms: a prospective multi-center open-label trial

BACKGROUND

Sodium hyaluronate (SH) solution has been used for submucosal injection in endoscopic resection to create a long-lasting submucosal fluid "cushion". Recently, we proved the usefulness and safety of 0.4% SH solution in endoscopic resection for gastric mucosal tumors. To evaluate the usefulness of 0.4% SH as a submucosal injection solution for colorectal endoscopic resection, we conducted an open-label clinical trial on six referral hospitals in Japan.

METHODS

A prospective multi-center open-label study was designed. A total of 41 patients with 5-20 mm neoplastic lesions localized in the colorectal mucosa at six referral hospitals in Japan in a single year period from December 2002 to November 2003 were enrolled and underwent endoscopic resection with SH. The usefulness of 0.4% SH was assessed by the en bloc complete resection and the formation and maintenance of mucosal lesion-lifting during endoscopic resection. Safety was evaluated by analyzing adverse events during the study period.

RESULTS

The usefulness rate was high (82.5%; 33/40). The following secondary outcome measures were noted: 1) steepness of mucosal lesion-lifting, 75.0% (30/40); 2) intraoperative complications, 10.0% (4/40); 3) time required for mucosal resection, 6.7 min; 4) volume of submucosal injection, 6.8 mL and 5) ease of mucosal resection, 87.5% (35/40). Two adverse events of bleeding potentially related to 0.4% SH were reported.

CONCLUSION

Using 0.4% SH solution enabled sufficient lifting of a colorectal intramucosal lesion during endoscopic resection, reducing the need for additional injections and the risk of perforation. Therefore, 0.4% SH may contribute to the reduction of complications and serve as a promising submucosal injection solution due to its potentially superior safety in comparison to normal saline solution.