Endoscopic mucosal resection

Optoacoustic mesoscopy for biomedicine

Fuelled by innovation, optical microscopy plays a critical role in the life sciences and medicine, from basic discovery to clinical diagnostics. However, optical microscopy is limited by typical penetration depths of a few hundred micrometres for in vivo interrogations in the visible spectrum. Optoacoustic microscopy complements optical microscopy by imaging the absorption of light, but it is similarly limited by penetration depth. In this Review, we summarize progress in the development and applicability of optoacoustic mesoscopy (OPAM); that is, optoacoustic imaging with acoustic resolution and wide-bandwidth ultrasound detection. OPAM extends the capabilities of optical imaging beyond the depths accessible to optical and optoacoustic microscopy, and thus enables new applications. We explain the operational principles of OPAM, its placement as a bridge between optoacoustic microscopy and optoacoustic macroscopy, and its performance in the label-free visualization of tissue pathophysiology, such as inflammation, oxygenation, vascularization and angiogenesis. We also review emerging applications of OPAM in clinical and biological imaging.

Potential of temperature-response collagen-genipin sols as a novel submucosal injection material for endoscopic resection

Background and study aims  We developed a novel submucosal (SM) injection material that contained pepsin-solubilized collagen (PSC), genipin (Ge) and phosphate buffer (PB). The aim of this study was to validate safety and usability of it for endoscopic resection (ER). Materials and methods  In preliminary studies, 1) appropriate warming time and concentration of Ge, and concentration of NaCl in PB, 2) storage modulus of PSC, Ge, and PB mixture (PSC/Ge), and PSC as a mechanical property, 3) histological finding after injection, and histological toxicity of PSC/Ge was evaluated. We injected PSC/Ge, PSC, sodium hyaluronate (SH), dextrose (DW), and normal saline (NS) into SM of resected porcine stomach. We compared mean height of mucosal elevation after immediate injection (MH) and mean retaining rate at 60 minutes (MR) as ex vivo study. Results  Optimal condition of PSC/Ge was Ge 5.5 mMol with 24 hours worming time and NaCl 280 mMol. PSC/Ge had better mechanical property than PSC. It was efficiently integrated and confined to the SM with acceptable toxicity. MH of PSC/Ge (5.1 ± 0.74 mm) and PSC (4.8 ± 0.84 mm) were significantly higher than NS (3.2 ± 0.84 mm). MR of PSC/Ge (100 ± 0.0%) was significantly higher than NS (61.7 ± 11.2%), DW (58.3 ± 11.8%) and SH (61.8 ± 8.6%). Conclusion  PSC/Ge and PSC has potential to be safe and usable for ER. PSC/Ge was better than PSC because of better mechanical property than PSC.

Solutions for submucosal injection: What to choose and how to do it

During the past decades, endoscopic resection techniques have gradually improved and gained more importance for the management of premalignant lesions and early cancers. These endoscopic resection techniques can be divided in 3 major groups: snare polipectomy, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD). The use of submucosal injection is essential for the majority of EMR techniques and is an integral part of ESD, whereas during polipectomy it is not crucial in most cases except to prevent bleeding in large polyps and/or those with large stalks as an alternative to mechanical methods. Injection provides a lifting up effect of the lesion separating it from the muscular layer, thereby reducing thermal injury and the risk of perforation and bleeding while also facilitating en-bloc resection by improving technical feasibility. With this work, we aim to review the most common endoscopic resection techniques and the importance of submucosal injection in each one of them. For that, we present some of the most commonly used submucosal injection solutions, taking into account their advantages and disadvantages. We also discuss, based on current recommendations and our own experience, how and when to preform submucosal injection, depending on lesions features and endoscopic resection technique that´s being used, to assure complete resection and to prevent associated adverse events. Finally, we also present and discuss some new proposed submucosal injection solutions, endoscopic resection techniques and devices that may have a major impact on the future of therapeutic endoscopy.

Identification of the critical viscoelastic factor in the performance of submucosal injection materials

High-performance submucosal injection materials (SIMs) contribute to the success of endoscopic therapy for early-stage gastrointestinal neoplasms. This study aimed to identify the most important factor (viscoelastic parameter) that determines SIM performance and the ease of injection. To determine the ideal viscoelastic parameters of SIMs, submucosal elevation heights (SEHs) and the ease of submucosal injection [characterized by injection pressures (IPs)] were evaluated using a newly developed ex vivo model, in which a constant tension was applied to the studied specimen. The strongest positive correlation was observed between the loss modulus determined at an oscillation frequency of 0.1 rad/s and SEH (correlation coefficient > 0.9) and between the loss modulus at 10 rad/s and IP (correlation coefficient > 0.9). SIMs with high loss moduli (0.1 rad/s) also contributed to maintenance of the submucosal elevation. Moreover, the SEHs of pseudoplastic fluid SIMs (whose loss moduli increased slightly with increasing angular frequency) were greater than those of Newtonian fluid SIMs (whose loss modulus increased drastically with increasing angular frequency). In this study, the ideal viscoelastic SIM parameters were clarified. The loss modulus (0.1 rad/s) was the most important viscoelastic factor affecting SIM performance. Additionally, the development of pseudoplastic fluid SIMs may lead to the creation of next-generation SIMs, with a performance superior to that of sodium hyaluronate, which is currently used widely in endoscopic treatments.

Characteristics of a Surgical Snare Using Microwave Energy

Currently, minimally invasive treatments that insert various treatment devices into an endoscope are actively being performed. A high-frequency (HF) snare is commonly used as an energy device inserted into an endoscope. However, using a high-frequency snare, problems usually occur, such as the obstruction of the visual field caused by smoke. On the other hand, microwave heating produces less smoke and provides a better visual field. In this study, a snare using microwave energy inserted into an endoscope is proposed, and its characteristics are evaluated.

Sclerotherapy needle injections can expand the subserosal and muscularis propria layers and cause a stable mucosal lift in ESD/EMR patients

Background

A mucosal lift is needed for ESD and EMR. Most lifts are made via sclerotherapy needle injection. The firm push needed to penetrate the mucosa often leaves the needle tip in the deep wall. The needle is next withdrawn and fluid injected until a sharp lift (due to submucosal expansion) begins to form; the needle is then held steady and the injection finished. The initial injection may result in a subtle deep lift that resolves quickly. It was the authors’ belief that only submucosal expansion could lead to a stable mucosal lift. A colonic ESD case in which a polyp was inadvertently resected via needle knife in an expanded subserosal plane led to a questioning of this position. This study’s purpose was to determine if stable deep wall mucosal lifts can be generated via bowel wall injection.

Methods

Transmucosal and intramural injections into bovine large bowel were carried out. Stable lifts and lift cross sections were made and examined grossly and histologically to determine the location of the lift fluid. Clinical ESD videos were also reviewed.

Results

Over 200 intact and cross-sectioned lifts were assessed. Gross inspection revealed two types of lifts (superficial and deep), whereas cross sections and histologic analyses revealed examples of stable expansion of the submucosal, muscularis propria, and subserosal layers post injection. Clinical “deep” lifts were also found. Superficial lifts are more focal and taller, whereas deep wall lifts are broader and less prominent.

Conclusion

Stable deep wall mucosal lifts occur and are likely due to the deep starting point of the needle post insertion. If ESD/EMR are attempted with a deep lift, the chances of failure or perforation are high. Lifts must be carefully scrutinized before starting ESD/EMR. Other means of lift establishment should be evaluated and considered.

Electronic supplementary material

The online version of this article (10.1007/s00464-018-6521-5) contains supplementary material, which is available to authorized users.

A New Ex Vivo Model for the Evaluation of Endoscopic Submucosal Injection Material Performance

Increasing the performance of submucosal injection materials (SIMs) is important for endoscopic therapy of early gastrointestinal cancer. It is essential to establish an ex vivo model that can evaluate SIM performance accurately, for developing high-performance SIMs. In our previous study, we developed a new ex vivo model that can be used to evaluate the performance of various SIMs in detail by applying constant tension to the specimen's ends. We also confirmed that the proposed new ex vivo model allows accurate submucosal elevation height (SEH) measurement under uniform conditions and detailed comparisons of the performances of various types of SIMs. Here, we describe the new ex vivo model and explain the detailed setup methodology of this model. Since all parts of the new model were easy to obtain, the setup of the new model could be completed quickly. SEH of various SIMs could be measured more accurately by using the new model. The critical factor that determines SIM performance can be identified using the new model. SIM development speed will drastically increase after the factor has been identified.

Role of endoscopic therapy in early esophageal cancer

Esophageal carcinoma is a highly lethal cancer associated with high morbidity and mortality. Esophageal squamous cell carcinoma and esophageal adenocarcinoma are the two distinct histological types. There has been significant progress in endoscopic diagnosis and treatment of early stages of cancer using resection and ablation techniques, as shown in several trials in the recent past. Earlier detection of esophageal cancer and advances in treatment modalities have lead to improvement in the 5-year survival from 5% to about 20% in the past decade. Endoscopic eradication therapy is the preferred modality of treatment in cancer limited to mucosal layer of the esophagus as there is very low risk of lymph node metastasis, leading to high cure rates, low risk of recurrence and with few adverse effects. The most common adverse events seen are strictures, bleeding and rarely perforation which can be endoscopically managed. In patients with recurrent advanced disease or invasive tumor, esophagectomy with lymph node dissection remains the mainstay of treatment. There is debate on post-endoscopic surveillance with some studies suggesting closer follow up with upper endoscopy every 6 mo for the first 1-2 years and then annually for the 3 years while others recommending the appropriate action only if symptoms or other abnormalities develop. Overall, the field of endoscopic therapy is still evolving and focus should be placed on careful patient selection using a multidisciplinary approach.

Endoscopic Closure of Large Defects With a Novel Clipping Device and a 4S-Modified Roeder Slipknot

Endoscopic closure is an essential procedure in gastrointestinal (GI) surgery, but currently it is difficult to close large defects endoscopically because of the lack of an appropriate device. Previously, we developed an endoscopic clipping device that has multifiring function and is equipped with an independent clamp. The goal of this study is to provide a new closure method with this device and 4S-modified Roeder (4SMR) slipknot. The feasibility of the closure method is examined by deploying two clips during one insertion onto the 4SMR slipknot to close a 5 cm full-thickness linear defect of an ex vivo porcine stomach from the center. Mechanical strengths of clip-knot closure and the slipknot as regards to tensioning forces are also evaluated. Specifically, the mechanical strength of the 4SMR slipknot is verified by mean peak forces to failure, while the knot is tensioning by 2.5, 5, 7.5, and 10 N force (n = 20 for each group), respectively. Experimental results indicate the clip-slipknot closure can withstand a distracting force of 6.3 ± 5.6 N. Tensioning force has a great influence on the mechanical strength of slipknot, with the mean peak force (tensioning force) being 7.1± 6.5, 16.3 ± 9.3, 18.9 ± 10.4, and 24.2 ± 12.0 N, respectively. The proposed closure method can be used for large defects. Tensioning force higher than 5 N is suitable to ensure a stronger 4SMR slipknot.

Endoscopic full-thickness resection for gastrointestinal submucosal tumors

Endoscopic full-thickness resection (EFTR) is a "changing-concept" endoscopic resection technique, which safely allows resecting deep submucosal tumors (SMTs) in the gastrointestinal (GI) wall. It's a highly promising endoscopic procedure that allows full-thickness excision of a small piece of the complete GI wall by using only a flexible endoscope. EFTR is a meeting point between surgery and endoscopy and probably the onset of many prospective combined minimally invasive therapeutic techniques that science will explore. In this review, use of the EFTR technique for gastrointestinal SMTs is highlighted, focusing on some technical aspects, indications, contraindications and outcomes.

Closing the Gaps: Endoscopic Suturing for Large Submucosal and Full-Thickness Defects

This article is a systematic review of relevant literature on endoscopic suturing as a primary closure technique for large submucosal and full-thickness defects after endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and endoscopic full-thickness resection (EFTR). A comprehensive literature search was conducted through 2016 by using PubMed, to find peer-reviewed original articles. The specific factors considered were the procedural indications and details, success rates, clinical outcomes including complications, and study limitations. Six original articles were included in the final review: two with non-human subjects and four with human subjects. The mean success rate of endoscopic suturing was 97.4% (100% for human subjects and 95.4% for non-human subjects). The procedural time ranged from 7 to 89 min. The average size and depth of lesions were 2.71 cm (3.74 cm [human] and 1.96 cm [non-human]) and 1.52 cm, respectively. The technique itself had no reported impact on mortality. In conclusion, endoscopic suturing is a minimally invasive technique for the primary closure of defects caused by EMR, ESD, and EFTR, with a high success and low complication rate.

EMR is superior to rectal suction biopsy for analysis of enteric ganglia in constipation and dysmotility

BACKGROUND AND AIMS

Patients with chronic constipation or motility disorders may be referred for rectal suction biopsy (RSB) to rule out Hirschsprung's disease (HD). RSB may not be successful beyond infancy because of the increased thickness of the rectal mucosa. EMR could improve the diagnostic yield for HD when compared with traditional RSB because larger and deeper samples are acquired for analysis.

METHODS

In this prospective, single-center study, patients referred for RSB were offered enrollment for concurrent EMR. Specimens were analyzed pathologically for size, submucosal ganglionic tissue, and acetylcholinesterase or calretinin staining. Biopsy results were compared with transit studies, anorectal manometry, and constipation severity through validated questionnaires.

RESULTS

Seventeen patients (2 male, 15 female; mean age, 35.8 years; range, 22-61 years) were enrolled in the study from 2008 to 2014. All patients underwent anorectal manometry (88% with anorectal dysfunction, 68% with outlet obstruction) and transit studies (41% with delayed transit). There were no reports of adverse events from the RSB and EMR procedures. The RSB sample volumes were significantly lower than the EMR sample volumes (0.023 cm³ vs 0.26 cm³, P = .001). There was diagnostic tissue for submucosal visualization by RSB in 53% (9/17) of cases compared with 100% (17/17) with EMR (P = .003). No cases of HD were diagnosed by RSB; one patient had rare ganglions observed by EMR.

CONCLUSIONS

EMR provides greater tissue volume and can improve the characterization of ganglion cells in rectal tissue compared with RSB in patients with moderate to severe constipation with suspected HD.

Splash M-knife versus Flush Knife BT in the technical outcomes of endoscopic submucosal dissection for early gastric cancer: a propensity score matching analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) is a standard treatment for early gastric cancer. A new multi-functional ESD device was developed to achieve complete ESD with a single device. A metal plate attached to its distal sheath achieves better hemostasis during the procedure than the other needle-knife device, Flush Knife BT®, that has been conventionally used. The aim of this study was to compare the technical outcomes of ESD for early gastric cancer using the Splash M-Knife® with those using the Flush Knife BT.

METHODS

We conducted a retrospective review of the case records of 149 patients with early gastric cancer treated with ESD using the needle-type ESD knives between January 2012 and August 2016 at Kitakyushu Municipal Medical Center. Lesions treated with ESD using the Splash M-knife (ESD-M) and the Flush Knife BT (ESD-F) were compared. Multivariate analyses and propensity score matching were used to compensate for the differences in age, gender, underlying disease, antithrombotic drug use, lesion location, lesion position, macroscopic type, tumor size, presence of ulceration, operator level and types of electrosurgical unit used. The primary endpoint was the requirement to use hemostatic forceps in the two groups. The secondary endpoints of procedure time, en bloc and complete resection rates, and adverse events rates were evaluated for the two groups.

RESULTS

There were 73 patients in the ESD-M group, and 76 patients in the ESD-F group. Propensity score matching analysis created 45 matched pairs. Adjusted comparisons between the two groups showed a significantly lower usage rate of hemostatic forceps in the ESD-M group than in the ESD-F group (6.7% vs 84.4%, p < 0.001). Treatment outcomes showed an en bloc resection rate of 100% in both groups; complete resection rate of 95.6% vs 100%, p = 0.49; median procedure time of 74.0 min vs 71.0 min, p = 0.90; post-procedure bleeding of 2.2% vs 2.2%, p = 1, in the ESD-M and ESD-F groups, respectively. There were no perforations in either group.

CONCLUSIONS

ESD-M appeared to reduce the usage of hemostatic forceps during ESD for early gastric cancer without increasing the adverse effects. Thus, it may contribute to a reduction in the total ESD cost.

Long-Term Clinical Efficacy and Perioperative Safety of Endoscopic Submucosal Dissection versus Endoscopic Mucosal Resection for Early Gastric Cancer: An Updated Meta-Analysis

BACKGROUND

To systematically evaluate the safety and efficacy of endoscopic submucosal dissection (ESD) versus endoscopic mucosal resection (EMR) for early gastric cancer (EGC).

METHODS

We searched the databases of PubMed, Web of Science, EMBASE, and the Cochrane Library from January 2000 to April 2017 and included studies that compared the outcomes of ESD with EMR for EGC. These eligible studies that met the inclusion criteria were screened out and were assessed by two independent investigators.

RESULT

In total, 18 retrospective cohort studies were eligible for analysis. Our results indicated that ESD is more beneficial than EMR in increasing the complete resection rate and en bloc resection rate and decreasing the local recurrence rate. However, ESD prolonged operative time and increased incidence of gastric perforation than EMR. No differences were found in postoperative bleeding rate between the two approaches.

CONCLUSION

Compared with EMR, ESD offers higher complete resection rate, higher en bloc resection rate, and lower local recurrence rate but has prolonged operative time and increased incidence of gastric perfusion. There is no statistical difference in the rate of postoperative bleeding between the two groups. However, the above conclusion needs further verification by well-designed, randomized trials with larger samples and long follow-up periods.

Development of a new ex vivo model for evaluation of endoscopic submucosal injection materials performance

BACKGROUND AND AIMS

Development of high-performance submucosal injection materials (SIMs) contribute to the advancement of endoscopic therapy for early-stage gastrointestinal neoplasms. This study aimed to develop a new ex vivo model that mimics the human gastrointestinal tract to evaluate the performance (the height and duration of the submucosal elevation) of various SIMs in detail.

METHODS

A new ex vivo model that applies a constant tension to the tested specimen (the porcine gastric specimen) was developed. SIMs were injected into the submucosa at the center or edge of the tested specimen, and submucosal elevation heights (SEHs) were measured over time.

RESULTS

The average value and standard deviation of SEH determined using the conventional model (the tested specimen was fixed with pins) were higher than those obtained using the new model, which showed that the new model could precisely measure the SEH of a given SIM. In addition, the performance (SEH) of SIMs decreased with increasing tension applied to the specimen, suggesting that the performance of SIMs deteriorates with the over-expansion of the gastrointestinal tract. The submucosal elevation formed at the specimen edge disappeared faster than that formed at the specimen's center.

CONCLUSIONS

The proposed new ex vivo model allows accurate SEH measurement under uniform conditions and detailed comparison of the performances of various types of SIMs and can contribute to the development of high-performance materials.

Thermo-sensitive isopentane aerification for mucosal lift during endoscopic resection in animal models (with video)

BACKGROUND AND AIMS

Mucosal lift is critical for successful endoscopic treatment. Normal saline (NS) solution is widely used as the submucosal filler, but its short persistency restricts clinical endoscopic submucosal dissection (ESD). In this study, thermo-sensitive isopentane was introduced for submucosal injection. With a boiling point at 27.8°C, liquid isopentane can be easily applied, and gasification inflation can provide great support for submucosal lifting at body temperature. The feasibility and efficiency of isopentane were evaluated in this study.

METHODS

Porcine stomachs were used for in vitro evaluation. A 37°C water bath was used to mimic body temperature. Compared with NS, isopentane was studied for its lifting performance, including injection dosage, persistence of lifting strength, and efficacy for assisting submucosal dissection. The changes in submucosal tissue were also compared. For in vivo evaluation, rats were used to further compare the differences between isopentane and NS, including lifting efficacy, pathologic effect, and safety.

RESULTS

Compared with NS, the maximum lifting height was achieved with less isopentane (2% NS volume). Longer persistency and faster operation for submucosal dissection were also recorded for isopentane during the in vitro study. Aerification resulted in vacuolization of submucosal connective tissue, which facilitates EMR and postoperative recovery. The same results were confirmed in the rat model. With the same dosage, isopentane produced better mucosal elevation and larger range than NS. According to the histologic examination, no tissue injury was observed with isopentane application.

CONCLUSIONS

As a submucosal injection agent, the feasibility, efficacy, and safety of isopentane has been demonstrated. Thermo-sensitive aerification may be a promising approach to facilitate ESD.

Function-preserving surgery for gastric cancer: current status and future perspectives

The number of early gastric cancer (EGC) cases has been increasing because of improved diagnostic procedures including endoscopy and screening systems. Therefore, function-preserving gastrectomy (FPG) for EGC with the expectation of better quality of life (QOL) after surgery may be increasingly utilized, due to its association with low rate of lymph node metastasis and excellent survival and the possibility of employing less invasive procedures such as laparoscopic gastrectomy in combination. Pylorus-preserving gastrectomy (PPG) with curative intent lymph node dissection is a representative FPG that has been used in EGC, and its superiorities, indications, limitations, and survival benefits have already been reported in several retrospective studies. Laparoscopic proximal gastrectomy (LAPG) has also been employed in EGC of the upper third of the stomach; however, LAPG was found to be associated with major issues in achieving a balance between swallowing and reflux prevention. In patients with EGC in the upper third of the stomach, laparoscopy-assisted subtotal gastrectomy with a preserved, albeit very small, stomach may provide a better QOL and fewer postoperative complications. FPG is recommended as a surgical treatment for EGC if the indication is accurately diagnosed and strictly confirmed; however, these techniques in laparoscopic surgery present technical difficulties to surgeons without a certain degree of skills. Although many retrospective studies revealed the functional benefits or oncological safety with FPG, further prospective studies using large case series are necessary to reveal the value of FPG compared with the conventional procedures.

Two electrosurgical endo-knives for endoscopic submucosal dissection of colorectal superficial neoplasms: a prospective randomized study

BACKGROUND AND STUDY AIMS

Few studies have directly compared endo-knives for endoscopic submucosal dissection (ESD) in humans. We compared the performances of the Mucosectom2 and SB knife Jr.

PATIENTS AND METHODS

 Two trainee endoscopists performed ESD of 36 lesions in this prospective, randomized controlled trial. Mucosal incision with a 1.5-mm Dual knife and submucosal dissection using the Mucosectom2 were performed in 1 group. Mucosal incision with a 1.5-mm Dual knife and submucosal dissection with a SB knife Jr. were performed in the other group. The primary outcome was the ESD procedure time. Secondary outcomes were total procedure time, self-completion rates, and adverse events.

RESULTS

ESD time in Mucosectom2 patients was not significantly shorter than in SB knife Jr. patients (57 ± 32 min vs. 61 ± 44 min, respectively; P  = 0.94). Total procedure time in Mucosectom2 patients was not significantly shorter than in SB knife Jr. patients (81 ± 42 min vs. 82 ± 51 min, respectively; P =  0.85). The trainee self-completion rate was slightly higher in SB knife Jr. patients than in Mucosectom2 patients, although the difference was not significant (94 % vs. 100 %, respectively; P  = 0.959). Fewer hemostatic procedures using the Coagrasper were performed in Mucosectom2 patients than in SB knife Jr. patients, although the difference was not significant (0.62 vs. 0.7, respectively; P  = 0.432).

CONCLUSIONS

 Mucosectom2 and SB knife Jr. did not significantly differ in performance for colorectal ESD to safely and reliably enhance ESD. Knife selection is not as important for learning colorectal ESD as patient- and lesion-related factors.

Endoscopic gastric polypectomy assisted by laparoscopy for giant gastric and duodenal lesion treatment: Case series from two centres

Background:

Endoscopy has developed rapidly, generating new challenges. Today, there are several procedures done endoscopically with very good results. In the past, the assisted laparoscopic colon polypectomy has been described, reducing the morbidity of a bigger procedure. Nonetheless, little has been said about the use of hybrid surgery in the management of gastric or duodenal polyps.

Objectives:

Evaluating the safety and efficacy of the assisted laparoscopic gastric endoscopic polypectomy.

Patients and Methods:

A retrospective review of the database at our two centres was performed from 1996 to 2014. Thirteen patients were found in whom an assisted laparoscopic gastric or duodenal endoscopic tumour resection was performed.

Results:

Thirteen patients, eight males and five females, with a median age of 61 years and average body mass index of 29.3. The procedure was done effectively and no need for further procedures was required for any patient. No complications were reported in the early post-operative period.

Conclusions:

The study shows that assisted laparoscopic gastric endoscopic polypectomy is a feasible and safe procedure that can be used for the management of giant polyps, which cannot be resected with the classical endoscopic polypectomy reducing the morbidity and complications associated with larger procedures.

Endoscopic closure after intraluminal surgery

Endoscopic submucosal dissection is established as a curative endoscopic method for gastrointestinal epithelial neoplasms with a high possibility of complete en bloc resection; however, postoperative adverse events of bleeding and delayed perforation remain. To prevent or minimize them, several techniques for endoscopic mucosal closure have been introduced, such as using endoscopic clips, combined use of hemoclips and supplement devices, and specially designed endoscopic suturing devices. Furthermore, endoscopic full-thickness suturing technique for gastrointestinal wall defect has been developed based on the concept in natural orifice transluminal endoscopic surgery and endoscopic full-thickness resection. Several closure techniques, including over-the-scope clip, threaded bars inserted in a hollow needle, stitches or staplers, and a curved needle and thread are reported. Secure closure of the iatrogenic defect may further expand the range of therapeutic endoscopy. Accumulation of evidence for the efficacy of endoscopic closure and establishment of these techniques are desired.

Peroral endoscopic myotomy using FlushKnife BT: a single-center series

BACKGROUND AND STUDY AIMS

Peroral endoscopic myotomy (POEM) is an evolving new treatment strategy for achalasia. Although several kinds of electrosurgical knives have been used in performing POEM, the best device has yet to be determined. The FlushKnife BT is a waterjet-emitting short needle-knife with a small ball tip (BT) that offers the potential to perform all aspects of POEM with a single device. In this study, we evaluated the safety and efficiency of the FlushKnife BT for POEM.

PATIENTS AND METHODS

 A total of 54 consecutive patients with achalasia and other spastic esophageal motility disorders, such as jackhammer esophagus or distal esophageal spasm, who underwent POEM between January 2016 and August 2016, were included in this retrospective study.

RESULTS

 The median operation time was 73.0 minutes (range 39 - 184 minutes). All procedures were completed using only the FlushKnife BT without changing to any other electrosurgical instrument. The median number of additional submucosal injections with an injection needle was 0 (range 0 - 1). Endoscopic vessel sealing was performed a mean of 3 times (range 0 - 7). The median number of bleeding episodes requiring treatment with hemostatic forceps was 0 (range 0 - 5). There were no significant adverse events. Seven of 52 patients (13.5 %) reported symptoms of gastroesophageal reflux disease such as heartburn or acid reflux at 3 month follow-up.

CONCLUSIONS

 The FlushKnife BT enabled POEM to be performed with very few device exchanges, either for re-injection or to control intraoperative bleeding. In this uncontrolled case series, the ability of the FlushKnife BT to perform nearly all aspects of the POEM procedure seems to make it particularly well suited to this procedure.

Risk factors and management for gastric stenosis after endoscopic submucosal dissection for gastric epithelial neoplasm

BACKGROUND

Only a few studies have reported treatment options for stenosis after endoscopic submucosal dissection (ESD) for gastric neoplasms. This study aimed to identify the risk factors for and evaluate the management of stenosis after ESD for gastric epithelial neoplasms in the cardia and antrum.

METHODS

We retrospectively reviewed 1218 patients (1447 gastric epithelial neoplasms) who underwent ESD at Tonan Hospital from June 2004 to November 2015. Post-ESD stenosis was defined when a standard endoscope could not be passed through the site.

RESULTS

Post-ESD stenosis occurred in 10 (21.3%) of the 47 cardia cases and 14 (3.2%) of the 432 antrum cases. A wide resection of more than three fourths of the circumferential extent was the sole significant risk factor related to post-ESD stenosis in both cardia and antrum. Prophylactic endoscopic balloon dilation (EBD) was performed in 3 of 10 patients with cardiac stenosis and 4 of 14 with antral stenosis. Post-EBD bleeding occurred in one cardia (10%) and one antrum (7.1%) case each and was endoscopically treated. Perforation during EBD occurred in two (14.3%) antrum cases, both of which required emergency open surgery. All complications were observed in patients with conventional EBD, and no complications were associated with prophylactic EBD.

CONCLUSIONS

A wide resection of more than three fourths of the circumferential extent was the significant risk factor for post-ESD stenosis in both cardia and antrum, and prophylactic EBD could be a promising procedure for the management of post-ESD stenosis.

Future Development of Endoscopic Accessories for Endoscopic Submucosal Dissection

Endoscopic submucosal dissection (ESD) has recently been accepted as a standard treatment for patients with early gastric cancer (EGC), without lymph node metastases. Given the rise in the number of ESDs being performed, new endoscopic accessories are being developed and existing accessories modified to facilitate the execution of ESD and reduce complication rates. This paper examines the history underlying the development of these new endoscopic accessories and indicates future directions for the development of these accessories.

Efficacy of a new hemostatic forceps during gastric endoscopic submucosal dissection: A prospective randomized controlled trial

BACKGROUND AND AIM

Currently, endoscopic submucosal dissection (ESD) is a widely accepted standard treatment for early gastric cancer, but one challenging aspect of ESD is hemostasis. We developed a new hemostatic forceps (FD-Y0007) with the aim of achieving more effective hemostasis and investigated the hemostatic ability of the FD-Y0007 during gastric ESD in humans.

METHODS

This study was a prospective randomized controlled trial, which was conducted at a cancer referral center. Sixty-six patients who were scheduled to undergo ESD were enrolled and randomly assigned to either the Coagrasper or the FD-Y0007, which was used for hemostasis throughout the case. The primary end point was the time required to obtain hemostasis, which was measured for the first episode of bleeding during each case.

RESULTS

Hemostasis time for the first bleeding episode during ESD was 73.0 s for the Coagrasper and 21.5 s for the FD-Y0007 (P < 0.001). When all episodes of bleeding were included, hemostasis time was 56.8 s in the Coagrasper group and 25.5 s in FD-Y0007group (P < 0.0001). The frequency of adverse events (perforation: 3.4% vs 7.1%; delayed bleeding: 0% vs 0%) was not significantly different between the two groups.

CONCLUSIONS

Compared with the Coagrasper, the FD-Y0007 efficiently reduces the hemostatic time during gastric ESD with no increase in adverse events.

Endoscopic Management of Early Esophagogastric Cancer

Esophagogastric cancer accounts for the second most common cause of cancer-related mortality worldwide. Significant efforts have been made to detect these malignancies at an earlier stage through the implementation of screening programs in high-risk individuals using advanced diagnostic techniques. Endoscopic management techniques, such as endoscopic mucosal resection and endoscopic submucosal dissection, have consistently demonstrated excellent outcomes in the management of these lesions. These techniques are associated with a lower risk of morbidity and mortality when compared with traditional surgical management.

Clinicopathological characteristics of patients who underwent additional gastrectomy after incomplete endoscopic resection for early gastric cancer

To evaluate the clinicopathological characteristics and factors that lead to residual tumors in patients who underwent additional gastrectomy for incomplete endoscopic resection (ER) for early gastric cancer (EGC).Between 2003 and 2013, the medical records of patients underwent additional gastrectomy after incomplete ER were retrospectively reviewed. Those diagnosed with the presence of histologic residual tumor in specimens obtained by gastrectomy were assigned to the residual tumor (RT) group (n = 47); those diagnosed with the absence of histologic residual tumor were assigned to the nonresidual tumor (NRT) group (n = 33).In the multivariate analysis, endoscopic piecemeal resection, Helicobacter pylori infection, large tumor size (>2 cm), and both (lateral and vertical) marginal involvement were independent factors of the presence of residual tumor in additional gastrectomy after incomplete resection ER for EGC and the rates of independent factors were significantly higher in the RT group than in the NRT group (P < 0.05).Before ER, preexamination to accurately determine the GC invasion depth and the presence of LN metastasis is very important. During ER, surgeons should attempt to perform en bloc resection and to resect the mucous membrane with adequate safety margins to prevent tumor invasion into the lateral and vertical margins.

Endoscopic Management of Large (≥2 cm) Non-pedunculated Colorectal Polyps: Impact of Polyp Morphology on Outcomes

BACKGROUND AND AIMS

Referrals for endoscopic management of large non-pedunculated (NP) colorectal polyps have increased as new techniques have emerged. The outcomes for referred large NP polyps based on the polyp morphology were investigated METHODS: A retrospective review of patients referred for large (≥20 mm) NP polyp management from January 2010 through June 2014 was completed. Polyp morphology was classified as either a NP polyp with depression (M1) or NP polyp with no depression (M0). Differences in treatment, histology, adverse events, outcomes at follow-up including residual disease, and need for surgical treatment were determined by morphology for all NP polyps ≥20 mm in size.

RESULTS

One-hundred and sixty-nine M1 and 136 M0 polyps ≥20 mm were removed endoscopically during the review period. Mean size was 31.9 ± 11.0 mm in M1, and 26.8 ± 9.5 mm in M0 group (p < 0.0001). En bloc resection was possible in 18.3 % of M1 and 30.9 % of M0 lesions (p = 0.011) with endoscopic submucosal dissection used in 13 and 2.2 % of polyps, respectively (p < 0.0001). Residual polyp was found in 26.5 % (27/102) of M1 and 13.6 % (12/88) of M0 patients at surveillance colonoscopy (p = 0.029). On multivariate analysis, piecemeal resection and M1 morphology showed significant association with residual polyp (OR 4.23, 95 % CI 1.23-14.59, p = 0.022, and OR 2.15, 95 % CI 1.004-4.62, p = 0.049, respectively).

CONCLUSION

Effective endoscopic management of large NP colorectal polyps, especially polyps without depression (M0), can be accomplished in the great majority of patients. Polyp morphology, particularly the presence or absence of depression, is a useful tool which influenced treatment, histology, and outcomes.

Surveillance after endoscopic and surgical resection of colorectal cancer

With the increase in colorectal cancer burden, surveillance following endoscopic and surgical resection is an essential issue. The aim of surveillance programs is improvement of patient survival by early detection of residual tumor tissue or local recurrence, metachronous colorectal tumors, and metastases. Appropriate surveillance should be determined according to this risk of factors. In current guidelines, only surveillance colonoscopy is recommended after endoscopic resection of polyps with high-grade dysplasia, whereas intensive, multimodality surveillance using colonoscopy, radiological imaging and tumor marker measurements is recommended following surgical resection of invasive colorectal cancer. Detailed recommendations, including the timing of surveillance, are described based on high-quality evidence. However, there are still many unresolved issues for which more high-quality evidence is required.

Prophylactic steroid administration for strictures after endoscopic resection of large superficial esophageal squamous cell carcinoma

Background and study aims: One of the major complications after endoscopic resection (ER) for large superficial esophageal squamous cell carcinoma (ESCC) is benign esophageal stricture, which can reduce quality of life even if ESCC achieves a cure without organ resection. Recently, steroid administration has been reported as a prophylactic treatment to prevent esophageal strictures. This retrospective study evaluated the stricture rate according to the different width of mucosal defects due to ER and compared it to that seen with prophylactic steroid administration. Patients and methods: Between June 2007 and December 2013, we enrolled patients with ESCC who had 3/4 or larger circumferential mucosal defects due to ER. In December 2009, steroid injections (triamcinolone acetonide 50 mg) into the ulcer bed due to ER were introduced. Beginning in November 2012, we commenced oral steroid administration (prednisolone 30 mg/day, tapered gradually for 8 weeks) in addition to steroid injection. Patients were classified into 3 groups according to the width of mucosal defect after ER (Group A, ≥ 3/4 and < 7/8; Group B, ≥ 7/8 and less than the entire circumference; and Group C, the entire circumference). We retrospectively evaluated the stricture rate by comparing no treatment, steroid injection, or steroid injection followed by oral steroid according to the width of mucosal defect. Results: A total of 115 patients met the selection criteria. In Group B, no treatment had a significantly higher stricture rate (100 %, vs. steroid injection: 56 % P = 0.015; vs steroid injection followed by oral steroid: 20 % P < 0.001). Conversely, in Group C, the stricture rate was high, regardless of treatment (no treatment: 100 %; steroid injection: 100 %; steroid injection followed by oral steroid: 71 %). Conclusions: Although prophylactic steroid administration is effective to prevent strictures for 7/8 circumference or larger mucosal defects, it is ineffective for whole-circumference defects. Further investigation is required.

Expanded endoscopic therapy criteria should be cautiously used in intramucosal gastric cancer

OBJECTIVE

Accurate estimation of lymph node metastasis (LNM) in intramucosal gastric cancer is essential to select less invasive treatment options and even avoid surgery. The aim of this study was to evaluate combined clinicopathological features to predict the presence of LNM.

METHODS

A retrospective review of data from 386 intramucosal gastric cancer patients who underwent gastrectomy with extended lymphadenectomy from 2003 to 2010 was conducted. The mutual relation between clinicopathological characteristics and LNM was analyzed.

RESULTS

LNM was detected in 40 (10.4%) of the 386 patients. Histological type and vascular or lymphatic invasion presence showed a positive correlation with LNM occurrence by univariate analysis. Multivariate analysis revealed that histological type was the only factor associated with LNM. Combined clinicopathologic characteristics would be more predictable for LNM. We found no LNM when we used combined clinicopathological characteristics conforming to Japanese absolute indications for endoscopic therapy. The LNM rate was as high as 8.7% when Japanese expanded criteria were used. Univariate analysis in cancer conformity to expand endoscopic submucosal dissection (ESD) indication also revealed that the undifferential type was the only significant factor for LNM.

CONCLUSIONS

It was possible to predict intramucosal gastric cancer cases without LNM using combined clinicopathological characteristic analysis. Extended indication for ESD should be cautiously used for intramucosal gastric cancer patients.

Correlation between endoscopic forceps biopsies and endoscopic mucosal resection with endoscopic ultrasound in patients with Barrett's esophagus with high-grade dysplasia and early cancer

BACKGROUND

Patients with Barrett's esophagus (BE) and high-grade dysplasia (HGD) or intramucosal cancer (IMC) on endoscopic forceps biopsies are referred to endoscopic therapy even though forceps biopsies do not reflect the disease extent accurately. Endoscopic mucosal resection (EMR) and endoscopic ultrasound (EUS) are frequently used for staging prior to endoscopic therapy. Our aims were to evaluate: (1) if endoscopic forceps biopsies correlated with EMR histology in these patients; (2) the utility of EUS compared to EMR; and (3) if accuracy of EUS varied based on grade of differentiation of tumor.

METHODS

This is a retrospective review of patients referred to endoscopic therapy of BE with HGD or early esophageal adenocarcinoma (EAC) who underwent EMR from 2006 to 2011. Age, race, sex, length of Barrett's segment, hiatal hernia size, number of endoscopies and biopsy results and EUS findings were abstracted.

RESULTS

A total of 151 patients underwent EMR. In 50 % (75/151) of patients, EMR histology was consistent with endoscopic forceps biopsy findings. EMR resulted in change in diagnosis with upstaging in 21 % (32/151) and downstaging in 29 % (44/151). In patients with HGD on EMR, EUS staging was T0 in 74.1 % (23/31) but upstaged in 25.8 % (8/31). In patients with IMC on EMR, EUS findings were T1a in 23.6 % (9/38), upstaged in 18.4 % (7/38) and downstaged in 57.8 % (22/38). EUS accurately identified EMR histology in all submucosal cancers. Grade of differentiation was reported in 24 cancers on EMR histology. There was no correlation between grade and EUS staging.

CONCLUSIONS

EUS is of limited utility in accurate staging of BE patients with HGD or early EAC. Endoscopic forceps biopsy correlated with EMR findings in only 50 % of patients. Irrespective of the endoscopic forceps biopsy results, all BE patients with visible lesions should be referred to EMR.

Feasibility of laparoscopic and endoscopic cooperative surgery for gastric submucosal tumors (with video)

BACKGROUND AND AIMS

Laparoscopic gastric resection is widely used for gastric submucosal tumors (SMTs). However, determining an appropriate resection line using only the laparoscopic approach is difficult. We developed a laparoscopic and endoscopic cooperative surgery (LECS) technique by combining laparoscopic gastric resection with endoscopic submucosal dissection, and we have used this procedure to resect gastric SMTs. In this study, the procedure is presented and its safety and feasibility for resecting gastric SMTs are evaluated.

METHODS

This retrospective study included 100 patients who underwent LECS for SMTs at the Department of Gastroenterological Surgery, Cancer Institute, between June 2006 and November 2014. The demographics, tumor histopathologic characteristics, and operative and follow-up data were reviewed.

RESULTS

Complete resection with negative surgical margins was achieved in all patients, and LECS was performed regardless of tumor location. The mean operation time was 174.3 minutes, with an estimated blood loss of 16.3 mL. In addition, the mean time until the initiation of oral intake was 1.4 days, and the mean postoperative hospital stay was 8.4 days. Moreover, no local or distant tumor recurrence was observed. The only severe adverse event was leakage, which was observed in 1 patient.

CONCLUSIONS

LECS was performed with a reasonable operation time, low blood loss, and minimal adverse events. Therefore LECS is safe and feasible for resecting gastric SMTs.

Endoscopic mucosal resection (EMR) versus endoscopic submucosal dissection (ESD) for resection of large distal non-pedunculated colorectal adenomas (MATILDA-trial): rationale and design of a multicenter randomized clinical trial

Background

Endoscopic mucosal resection (EMR) is currently the most used technique for resection of large distal colorectal polyps. However, in large lesions EMR can often only be performed in a piecemeal fashion resulting in relatively low radical (R0)-resection rates and high recurrence rates. Endoscopic submucosal dissection (ESD) is a newer procedure that is more difficult resulting in a longer procedural time, but is promising due to the high en-bloc resection rates and the very low recurrence rates. We aim to evaluate the (cost-)effectiveness of ESD against EMR on both short (i.e. 6 months) and long-term (i.e. 36 months). We hypothesize that in the short-run ESD is more time consuming resulting in higher healthcare costs, but is (cost-) effective on the long-term due to lower patients burden, a higher number of R0-resections and lower recurrence rates with less need for repeated procedures.

Methods

This is a multicenter randomized clinical trial in patients with a non-pedunculated polyp larger than 20 mm in the rectum, sigmoid, or descending colon suspected to be an adenoma by means of endoscopic assessment. Primary endpoint is recurrence rate at follow-up colonoscopy at 6 months. Secondary endpoints are R0-resection rate, perceived burden and quality of life, healthcare resources utilization and costs, surgical referral rate, complication rate and recurrence rate at 36 months. Quality-adjusted-life-year (QALY) will be estimated taking an area under the curve approach and using EQ-5D-indexes. Healthcare costs will be calculated by multiplying used healthcare services with unit prices. The cost-effectiveness of ESD against EMR will be expressed as incremental cost-effectiveness ratios (ICER) showing additional costs per recurrence free patient and as ICER showing additional costs per QALY.

Discussion

If this trial confirms ESD to be favorable on the long-term, the burden of extra colonoscopies and repeated procedures can be prevented for future patients.

Trial registration

NCT02657044 (Clinicaltrials.gov), registered January 8, 2016.

Examination of Surgical Specimens of the Esophagus

CONTEXT

Esophageal cancer continues to be one of the most lethal of all gastrointestinal malignancies. Its prognostic parameters are based on the gross and histopathologic examination of resected specimens by pathologists.

OBJECTIVE

To describe the implications of appropriate handling and examination of endomucosal resection and esophagectomy specimens from patients with esophageal carcinoma while considering the implications of the surgical techniques used to obtain such specimens. Parameters include histopathologic findings necessary for accurate staging, differences in the assessment of margins, residual malignancy, and criteria to evaluate for tumor regression after chemoradiation therapy as well as the role of immunohistochemistry and the judicious use of frozen sections.

DATA SOURCES

Sources were a review of the literature and the authors' experience handling these types of specimens.

CONCLUSIONS

Examining surgical specimens of the esophagus is critical in the management of patients with esophageal carcinoma, and it requires careful consideration of the diagnostic pitfalls, staging-related parameters, and results of molecular tests.

IMPROVED EXPERIMENTAL MODEL TO EVALUATE SUBMUCOSAL INJECTION SOLUTIONS FOR ENDOSCOPIC SUBMUCOSAL DISSECTION

Background :

Endoscopic submucosal dissection carries an increased risk of bleeding and perforation. The creation of a long lasting submucosal cushion is essential for the safe and complete removal of the lesion. There is not a suitable experimental model for evaluation of the durability of the cushioning effect of different solutions.

Aim :

To describe an improved experimental model to evaluate submucosal injection solutions.

Methods :

A total of four domestic pigs were employed to evaluate two different submucosal fluid solutions in the gastric submucosa. After midline laparotomy, the anterior gastric wall was incised from the gastric body to the antrum and its mucosal surface was exposed by flipping inside out the incised gastric wall. Two different solutions (10% mannitol and normal saline) were injected in the submucosa of the anterior wall of the distal gastric body. All submucosal cushions were injected until they reach the same size, standardized as 1.0 cm in height and 2.0 cm in diameter. A caliper and a ruler were employed to guarantee accuracy of the measurements.

Results :

All four animal experiments were completed. All submucosal cushions had the exact same size measured with caliper and a ruler. By using the mannitol solution, the mean duration of the submucosal cushion was longer than the saline solution: 20 and 22 min (mean, 21 min) vs 5 and 6 min (mean, 5.5 min)

Conclusions :

This experimental model is simple and evaluate the duration, size, and effect of the submucosal cushion, making it more reliable than other models that employ resected porcine stomachs or endoscopic images in live porcine models.

Thread-Traction with a Sheath of Polypectomy Snare Facilitates Endoscopic Submucosal Dissection of Early Gastric Cancers

Although the thread-traction (TT) method has been found useful during endoscopic submucosal dissection (ESD) for early gastric cancers, the movement of the thread interferes with the movement of the endoscope, and the lesion can only be pulled to the mouth side. We have developed the novel TT method using a sheath of polypectomy snare (TTSPS). The TTSPS method enables free and independent movement of the thread and the endoscope and allows pulling the lesion towards the anal as well as oral side. The median dissection times, numbers of instances of arterial bleeding, and numbers of local injections into the submucosal layer were significantly lower for ESD with TTSPS than for conventional ESD. Countertraction ESD using the TTSPS method is straightforward, safe, easy, noninvasive, and cost effective, and it uses instruments readily available in most hospitals to enhance visualization of cutting lines. Therefore, the TTSPS method can be universally applied in conventional ESD.

A feasibility study of a thermally sensitive elastin-like polypeptide for submucosal injection application in endoscopic resection in 3 animal models

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) can successfully resect large lesions en bloc by using a submucosal injection solution, but the cost of currently available submucosal injection solutions is not satisfactory. The authors' aim was to evaluate the feasibility and effectiveness of a thermally sensitive elastin-like polypeptide (ELP) used as submucosal injection solution in ESD.

METHODS

We conducted an ex vivo study to determine the optimal concentration of ELPs in rabbits, an in vivo study to evaluate the effectiveness of mucosal elevation in rats, and a large animal study to confirm the feasibility of preclinical application by using conventional clinical procedure in pigs.

RESULTS

ELP (500 μM) was proved to be the optimal injectable submucosal injection solution and elevated mucosa more efficiently than any control. The same concentration of ELP exhibited an equivalent effectiveness of mucosal elevation, the retention of the elevation, and minimal bleeding with sodium hyaluronate. The ESD procedure time with 500 μM ELP in a preclinical study with pigs was significantly shorter than with any other concentration of ELP and normal saline solution.

CONCLUSIONS

Use of ELP as submucosal injection solution was feasible, with higher and longer-lasting elevation and fewer adverse events.

Value of Magnifying Endoscopy With Narrow-Band Imaging and Confocal Laser Endomicroscopy in Detecting Gastric Cancerous Lesions

Although the respective potentials of magnifying endoscopy with narrow-band imaging (ME-NBI) and confocal laser endomicroscopy (CLE) in predicting gastric cancer has been well documented, there is a lack of studies in comparing the value and diagnostic strategy of these 2 modalities. Our primary aim is to investigate whether CLE is superior to ME-NBI for differentiation between gastric cancerous and noncancerous lesions. A secondary aim is to propose an applicable clinical strategy.We conducted a diagnostic accuracy study involving patients with suspected gastric superficial cancerous lesions. White light endoscopy, ME-NBI, and CLE were performed diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value between ME-NBI and CLE were assessed, as well as agreements between ME-NBI/CLE and histopathology.This study involved 86 gastric lesions in 82 consecutive patients who underwent white light endoscopy, ME-NBI, and CLE before biopsy. The accuracy, sensitivity, and specificity for ME-NBI were 93.75%, 91.67%, and 95.45%, compared with 91.86%, 90%, and 93.48%, respectively, for CLE, for discrimination cancerous/noncancerous lesion (all P > 0.05). For undifferentiated/differentiated adenocarcinoma, CLE had a numerically but not statistically significantly higher accuracy than ME-NBI (81.25% vs 73.33%, P = 0.46). Agreements between ME-NBI/CLE and histopathology were near perfect (ME-NBI, κ = 0.87; CLE, κ = 0.84).CLE is not superior to ME-NBI for discriminating gastric cancerous from noncancerous lesions. Endoscopist could make an optimal choice according to the specific indication and advantages of ME-NBI and CLE in daily practices.

Coagulation syndrome: Delayed perforation after colorectal endoscopic treatments

Various procedure-related adverse events related to colonoscopic treatment have been reported. Previous studies on the complications of colonoscopic treatment have focused primarily on perforation or bleeding. Coagulation syndrome (CS), which is synonymous with transmural burn syndrome following endoscopic treatment, is another typical adverse event. CS is the result of electrocoagulation injury to the bowel wall that induces a transmural burn and localized peritonitis resulting in serosal inflammation. CS occurs after polypectomy, endoscopic mucosal resection (EMR), and even endoscopic submucosal dissection (ESD). The occurrence of CS after polypectomy or EMR varies according previous reports; most report an occurrence rate around 1%. However, artificial ulcers after ESD are largely theoretical, and CS following ESD was reported in about 9% of cases, which is higher than that for CS after polypectomy or EMR. Most cases of post-polypectomy syndrome (PPS) have an excellent prognosis, and they are managed conservatively with medical therapy. PPS rarely develops into delayed perforation. Delayed perforation is a severe adverse event that often requires emergency surgery. Since few studies have reported on CS and delayed perforation associated with CS, we focused on CS after colonoscopic treatments in this review. Clinicians should consider delayed perforation in CS patients.

Outcomes and precautions of endoscopic submucosal dissection for undifferentiated-type early gastric cancer

OBJECTIVES

Since the development of techniques for endoscopic submucosal dissection (ESD), the indication range of endoscopic resection (ER) has been extended in early gastric cancer (EGC) treatment. For undifferentiated-type EGC, tumors with an intramucosal depth of invasion, no ulceration and a diameter of 20 mm or less were included in the expanded indications for ER in the Japanese Gastric Cancer Treatment Guidelines 2010. Nonetheless, because of difficulty in detecting lesions that meet the criteria for ER, the number of endoscopically resected cases of undifferentiated-type EGC is less than that of differentiated-type EGC.

METHODS

We retrospectively investigated the outcomes of ESD in 38 patients with 40 lesions of EGC in which the dominant pathological type was confirmed to be undifferentiated (signet ring cell carcinoma, poorly differentiated adenocarcinoma, mucinous adenocarcinoma) on histological examination of resected specimens.

RESULTS

Margin involvement and submucosal infiltration were common noncurative factors. Precise evaluation of the area and depth of lesions is a problem to be solved. Among a total of five patients with involved or uncertain horizontal margins, one of two patients who underwent additional surgery had residual cancer, and one of three patients who were observed had recurrence.

CONCLUSIONS

Undifferentiated-type EGC with a positive horizontal margin may relapse after ESD. It is therefore essential to precisely evaluate the area of the lesion and to perform resection with an adequate safety margin to decrease the risk of recurrence.

Risk factors for bleeding evaluated using the Forrest classification in Japanese patients after endoscopic submucosal dissection for early gastric neoplasm

BACKGROUND/AIMS

Bleeding remains a serious complication after endoscopic submucosal dissection (ESD). Second-look endoscopy for hemostasis helps prevent post-ESD bleeding. We investigated the relationships between patient characteristics, tumor characteristics, and the Forrest classification for exposed vessels on artificial ulcers after ESD and evaluated whether hemostasis during second-look endoscopy was useful for preventing post-ESD bleeding.

PATIENTS AND METHODS

We analyzed 250 patients (265 lesions) who underwent ESD for gastric neoplasms. Vessels classified by Forrest classifications during scheduled second-look endoscopy were analyzed for associations with patient characteristics, tumor characteristics, and recurrent bleeding.

RESULTS

Two of 250 patients (0.8%) underwent emergency hemostatic endoscopy before scheduled second-look endoscopy. The remaining 248 patients (99.2%) underwent scheduled second-look endoscopy on the day after ESD. Patients with Forrest classification Ia, Ib, or IIa vessels had a significantly higher risk for recurrent bleeding after scheduled second-look endoscopy compared with patients with IIb or III vessels according to univariate analysis (P<0.05) and multivariate logistic regression analysis (odds ratio: 3.45; 95% confidence interval: 1.04-11.41; P=0.042). Univariate analysis indicated that hemodialysis correlated significantly with the presence of Ia, Ib, or IIa vessels compared with that of IIb or III vessels found during second-look endoscopy (P<0.05). Multivariate analysis indicated a significant relationship between hemodialysis and recurrent bleeding after second-look endoscopy (odds ratio: 10.05; 95% confidence interval: 1.97-51.26; P=0.006).

CONCLUSION

Hemodialysis is a risk factor for post-ESD bleeding. Proper classification of exposed vessels within post-ESD ulcers according to the Forrest classification using second-look endoscopy might help predict or prevent recurrent bleeding.

Risk factors and correlations of immediate, early delayed, and late delayed bleeding associated with endoscopic resection for gastric neoplasms

BACKGROUND

Bleeding is a major complication following endoscopic resection (ER) of gastric mucosal lesions. We aimed to determine the risk factors for post-ER bleeding and their correlations according to the time elapsed since the procedure.

METHODS

We retrospectively enrolled 670 lesions in 610 patients who underwent ER between March 2009 and December 2010. We classified these lesions into three types in accordance with the bleeding time, i.e., immediate bleeding (IB), early delayed bleeding (EDB), and late delayed bleeding (LDB). We analyzed the risk factors for each bleeding type according to baseline patient characteristics, procedure-related factors, and correlations between the occurrence of each bleeding type.

RESULTS

There were 408 post-ER bleeding events in our study cohort: 302 IB events, 88 EDB events, and 18 LDB events. In multivariate analysis, a histologic finding of carcinoma and the resection time were significant predictors of IB (p < 0.001). Of the 302 IB events, 13.9% showed EDB. Additionally, LDB occurred in 2.4% of lesions with EDB and 4.6% of lesions without EDB. Similar to the IB group, of 368 lesions without IB, 12.5% showed EDB. In addition, LDB occurred in 2.2% of lesions with EDB and 1.2% of lesions without EDB. IB was associated with a higher risk of EDB (p < 0.001) and LDB (p < 0.001), whereas EDB was not related to an increased risk of LDB (p = 0.997).

CONCLUSION

IB significantly increases the risk of EDB and LDB, but EDB does not increase the risk of LDB. Histologically confirmed carcinoma or a prolonged time for resection increases the risk of post-ER IB. We recommend careful follow-up approaches following ER of a gastric mucosal lesion in high-risk patients to prevent a potentially critical occurrence of delayed bleeding.