Animal experimental study on magnetic anchor technique-assisted endoscopic submucosal dissection of early gastric cancer

BACKGROUND Gastric cancer(GC)has high morbidity and mortality.Moreover,because GC has no typical symptoms in the early stages,most cases are already in the advanced stages by the time the symptoms appear,thus resulting in poor prognosis and a low survival rate.Endoscopic submucosal dissection(ESD)can realize the early detection and diagnosis of GC and become the main surgical method for early GC.However,ESD has a steep learning curve and high technical skill requirements for endoscopists,which is not conducive to its widespread implementation and advancement.Therefore,a series of auxiliary techniques have been derived.AIM To evaluate the safety and efficacy of magnetic anchor technique(MAT)-assisted ESD in early GC.METHODS This was an ex vivo animal experiment.The experimental models were the isolated stomachs of pigs,which were divided into two groups,namely the study group(n=6)with MAT-assisted ESD and the control group(n=6)with traditional ESD.Comparing the total surgical time,incidence of surgical complications,complete mucosal resection rate,specimen size,and the scores of endoscopist’s satisfaction with the procedure reflected their feelings about convenience during the surgical procedure between the two groups.The magnetic anchor device for auxiliary ESD in the study group comprised three parts,an anchor magnet(AM),a target magnet(TM),and a soft tissue clip.Under gastroscopic guidance,the soft tissue clip and the TM were delivered to the pre-marked mucosal lesion through the gastroscopic operating hole.The soft tissue clip and the TM were connected by a thin wire through the TM tail structure.The soft tissue clip was released by manipulating the operating handle of the soft tissue clip in a way that the soft tissue clip and the TM were fixed to the lesion mucosa.In vitro,ESD is aided by maneuvering the AM such that the mucosal dissection surface is exposed.RESULTS The total surgical time was shorter in the study group than in the control group(26.57±0.19 vs 29.97±0.28,P<0.001),and the scores of endoscopist’s satisfaction with the procedure were higher in the study group than in the control group(9.53±0.10 vs 8.00±0.22,P<0.001).During the operation in the study group,there was no detachment of the soft tissue clip and TM and no mucosal tearing.The magnetic force between the AM and TM provided good mucosal exposure and sufficient tissue tension for ESD.The mucosal lesion was completely peeled off,and the operation was successful.There were no significant differences in the incidence of surgical complications(100%vs 83.3%),complete mucosal resection rate(100%vs 66.7%,P=0.439),and specimen size(2.44±0.04 cm vs 2.49±0.02,P=0.328)between the two groups.CONCLUSION MAT-ESD is safe and effective for early GC.It provides a preliminary basis for subsequent internal animal experiments and clinical research.

Buried bumper syndrome:A critical analysis of endoscopic release techniques

Buried bumper syndrome(BBS)is the situation in which the internal bumper of the gastrostomy tube,due to prolonged compression of the tissues between the external and the internal bumper,migrates from the gastric lumen into the gastric wall or further,into the tract outside the gastric lumen,ending up anywhere between the stomach mucosa and the surface of the skin.This restricts liquid food from entering the stomach,since the internal opening is obstructed by gastric mucosal overgrowth.We performed a comprehensive search of the PubMed literature to retrieve all the case-reports and case-series referring to BBS and its management,after which we focused on the endoscopic techniques for releasing the internal bumper to re-establish the functionality of the tube.From the“push”and the“push and pull T”techniques to the most sophisticated-using high tech instruments,all 10 published techniques have been critically analysed and the pros and cons presented,in an effort to optimize the criteria of choice based on maximum efficacy and safety.

Magnetic anchor technique assisted endoscopic submucosal dissection for early esophageal cancer

BACKGROUND Esophageal cancer has high incidence globally and is often diagnosed at an advanced stage.With the widespread application of endoscopic technologies,the need for early detection and diagnosis of esophageal cancer has gradually been realized.Endoscopic submucosal dissection(ESD)has become the standard of care for managing early tumors of the esophagus,stomach,and colon.However,due to the steep learning curve,difficult operation,and technically demanding nature of the procedure,ESD has currently been committed to the development of various assistive technologies.AIM To explore the feasibility and applicability of magnetic anchor technique(MAT)-assisted ESD for early esophageal cancer.METHODS Isolated pig esophagi were used as the experimental model,and the magnetic anchor device was designed by us.The esophagi used were divided into two groups,namely the operational and control groups,and 10 endoscopists completed the procedure.The two groups were evaluated for the following aspects:The total operative time,perforation rate,rate of whole mucosal resection,diameter of the peering mucosa,and scores of endoscopists’feelings with the procedure,including the convenience,mucosal surface exposure degree,and tissue tension.In addition,in the operational group,the soft tissue clip and the target magnet(TM)were connected by a thin wire through a small hole at the tail end of the TM.Under gastroscopic guidance,the soft tissue clip was clamped to the edge of the lesioned mucosa,which was marked in advance.By changing the position of the anchor magnet(AM)outside the esophagus,the pulling force and pulling direction of the TM could be changed,thus exposing the mucosal peeling surface and assisting the ESD.RESULTS Herein,each of the two groups comprised 10 isolated esophageal putative mucosal lesions.The diameter of the peering mucosa did not significantly differ between the two groups(2.13±0.06 vs 2.15±0.06,P=0.882).The total operative time was shorter in the operational group than in the control group(17.04±0.22 min vs 21.94±0.23 min,P<0.001).During the entire experiment,the TM remained firmly connected with the soft tissue clip and did not affect the opening,closing,and release of the soft tissue clip.The interaction between the TM and AM could provide sufficient tissue tension and completely expose the mucosa,which greatly assists the surgeon with the operation.There was no avulsion of the mucosa,and mucosal lesions were intact when peeled.Therefore,the scores of endoscopists’feelings were higher in the operational group than in the control group in terms of the convenience(9.22±0.19 vs 8.34±0.15,P=0.002),mucosal surface exposure degree(9.11±0.15 vs 8.25±0.12,P<0.001),and tissue tension(9.35±0.13 vs 8.02±0.17,P<0.001).The two groups did not significantly differ in the perforation rate and rate of whole mucosal resection.CONCLUSION We found MAT-assisted ESD safe and feasible for early esophageal cancer.It could greatly improve the endoscopic operation experience and showed good clinical application prospects.

Consensus on the digestive endoscopic tunnel technique

With the digestive endoscopic tunnel technique(DETT), many diseases that previously would have been treated by surgery are now endoscopically curable by establishing a submucosal tunnel between the mucosa and muscularis propria(MP). Through the tunnel, endoscopic diagnosis or treatment is performed for lesions in the mucosa, in the MP, and even outside the gastrointestinal(GI) tract.At present, the tunnel technique application range covers the following:(1)Treatment of lesions originating from the mucosal layer, e.g., endoscopic submucosal tunnel dissection for oesophageal large or circular early-stage cancer or precancerosis;(2) treatment of lesions from the MP layer, per-oral endoscopic myotomy, submucosal tunnelling endoscopic resection, etc.; and(3) diagnosis and treatment of lesions outside the GI tract, such as resection of lymph nodes and benign tumour excision in the mediastinum or abdominal cavity. With the increasing number of DETTs performed worldwide, endoscopic tunnel therapeutics, which is based on DETT, has been gradually developed and optimized. However, there is not yet an expert consensus on DETT to regulate its indications, contraindications, surgical procedure, and postoperative treatment.The International DETT Alliance signed up this consensus to standardize the procedures of DETT. In this consensus, we describe the definition, mechanism,and significance of DETT, prevention of infection and concepts of DETTassociated complications, methods to establish a submucosal tunnel, and application of DETT for lesions in the mucosa, in the MP and outside the GI tract(indications and contraindications, procedures, pre-and postoperative treatments, effectiveness, complications and treatments, and a comparison between DETT and other operations).

Endoscopic hemostasis techniques for upper gastrointestinal hemorrhage: A review

Upper gastrointestinal hemorrhage (UGIH) is an urgent disease that is often encountered in daily medical practice. Endoscopic hemostasis is currently indispensable for the treatment of UGIH. Initially, when UGIH is suspected, a cause of UGIH is presumed from the medical interview and physical findings. After ample primary treatment, urgent endoscopy is performed. Many methods of endoscopic hemostasis are in wide use, including hemoclip, injection and thermo-coagulation methods. Although UGIH develops from a wide variety of diseases, such as esophageal varices and gastric and duodenal ulcer, hemostasis is almost always possible. Identification of the causative diseases, primary treatment and characteristic features of endoscopic hemostasis are needed to allow appropriate treatment.

Effectiveness of clip-and-snare method using pre-looping technique for gastric endoscopic submucosal dissection

AIM:To evaluate efficacy and safety of clip-and-snare method using pre-looping technique(CSM-PLT)for gastric endoscopic submucosal dissection(ESD).METHODS:In the CSM-PLT method,a clip attached to the lesion side was strangulated with a snare,followed by application of an appropriate tension to the lesion independent of an endoscope.Twenty consecutive lesions were resected by ESD using CSM-PLT(CSM-PLT group)and compared with a control group,including20 lesions that were resected by conventional ESD.The control group was matched based on the size and location of the lesion,presence of pathologic fibrosis,and experience of endoscopists.Total procedure time of ESD,proportion of en bloc resection,and complications were analyzed.RESULTS:The total procedure time for the CSM-PLT group was significantly shorter than that for the control group(38.5 min vs 59.5 min,P=0.023);all lesions were resected en bloc by ESD.There was no significant difference in complications between the two groups.Moreover,there was no complication in the CSM-PLT group.In one large lesion(size:74 mm)that underwentextensive CSM-PLT during ESD,we used an additional CSM-PLT on another edge of the lesion after achieving submucosal resection to the maximum extent possible during initial CSM-PLT.In two lesions,the snare came off the lesion together with the clip after a sudden pull;nevertheless,ESD was successful in all lesions.CONCLUSION:CSM-PLT was an effective and safe method for gastric ESD.

New endoscopic ultrasound techniques for digestive tract diseases: A comprehensive review

Endoscopic ultrasound(EUS) is one of the most important modalities for the diagnosis of digestive tract diseases.EUS has been evolving ever since it was introduced.New techniques such as elastography and contrast enhancement have emerged, increasing the accuracy, sensitivity and specificity of EUS for the diagnosis of digestive tract diseases including pancreatic masses and lymphadenopathy.EUS-elastography evaluates tissue elasticity and therefore, can be used to differentiate various lesions.Contrast-enhanced EUS can distinguish benign from malignant pancreatic lesions and lymphadenopathy using the intravenous injection of contrast agents.This review discusses the principles and types of these new techniques, as well as their clinical applications and limitations.

New devices and techniques for endoscopic closure of gastrointestinal perforations

Gastrointestinal perforations,which need to be managed quickly,are associated with high morbidity and mortality. Treatments used to close these perforations range from surgery to endoscopic therapy. Nowadays,with the development of new devices and techniques,endoscopic therapy is becoming more popular. However,there are different indications and clinical efficacies between different methods,because of the diverse properties of endoscopic devices and techniques. Successful management also depends on other factors,such as the precise location of the perforation,its size and the length of time between the occurrence and diagnosis. In this study,we performed a comprehensive review of various devices and intro-duced the different techniques that are considered effective to treat gastrointestinal perforations. In addition,we focused on the different methods used to achieve successful closure,based on the literature and our clinical experiences.

Percutaneous Endoscopic Lumbar Spine Surgery for Lumbar Disc Herniation and Lumbar Spine Stenosis: Emphasizing on Clinical Outcomes of Transforaminal Technique

Lumbar Disc Herniation and Lumbar Spine Stenosis are the most common spine diseases which are mainly due to age related Spine degeneration. Diagnosis of both Lumbar Disc Herniation and Lumbar Spine Stenosis depends on clinical findings as well as radiological investigations. Treatment of choice of these conditions is on the basis of the patient conditions. Surgical treatment is the option only when the conservative treatment does not improve the patient’s clinical condition. Advancement and improvement of the technology have resulted in the traditional open surgical treatment into minimal invasive surgery. Intervention of the different surgical instruments with expert spinal surgeons had made percutaneous endoscopic lumbar Spine surgery as one of the preferred choices of surgery for treating Lumbar Disc Herniation and Lumbar Spine Stenosis. The concept of percutaneous endoscopic surgery for lumbar region is to provide surgical options without producing iatrogenic morbidity associated with the open surgical procedures. Conventionally, there are different approaches/techniques for Percutaneous Endoscopic Lumbar Spine Surgery, but in this review we are mainly focusing on the Transforaminal Technique. Regarding the Lumbar Disc Herniation treatment with transforaminal approach, a number of articles have been published due to which we mainly focused on those articles which were published after 2009 onwards. While fewer articles related to Lumbar Spine Stenosis treatment with Transforaminal approach were found, we tried to brief out all those articles. On the basis of comparative study of different surgeries done for Lumbar Disc Herniation and Lumbar Spine Stenosis, Percutaneous Transforaminal endoscopic Lumbar Surgery provides a substantial benefit. Transforaminal approach for treating Lumbar Disc Herniation and Lumbar Spine Stenosis is safe and effective. The Percutaneous Transforaminal Endoscopic Lumbar Surgery has advantage as it is performed under local anesthesia with shorter length of hospitalization and early return to normal life. The clinical outcome of the patient that underwent Percutaneous Transforaminal Endoscopic Lumbar Surgery for Lumbar Disc Herniation and Lumbar Spine Stenosis is quite good in regard of its fewer complication and more benefits.

Endoscopic ultrasound fine needle aspiration:Technique and applications in clinical practice

Since its initial report in 1992,endoscopic ultrasoundguided fine needle aspiration(EUS-FNA) has now been incorporated into the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of adjacent organs.Its introduction constitutes a major breakthrough in the endoscopic field and has gradually transformed EUS from a pure imaging modality into a more interventional procedure.In addition,the possibility of collecting samples,providing a definitive cytological and/or histological evidence of the presence of malignancy,has strongly contributed to changing EUS from a subjective,highly operator dependant procedure into a more objective one.This article will review the instrumentation,technique and the most important clinical applications of EUS-FNA.

Endoscopic treatment of non-variceal gastrointestinal bleeding:hemoclips and other hemostatic techniques

Although the number of hospitalizations for non-variceal gastrointestinal bleeding has decreased inrecent years,acute upper gastrointestinalhemorrhage continues to be a common reason forhospital admission,and peptic ulcers account for atleast fifty percent of all cases.Despite the fact thatbleeding from ulcers ceases spontaneously inapproximately 80% of patients,it is still a

Management of chronic dacryocystitis cases after failed external dacryocystorhinostomy using endoscopic technique with a novel lacrimal ostium stent

AIM: To demonstrate the outcomes of endoscopic endonasal dacryocystorhinostomy(En-DCR) with an novel lacrimal ostium stent(LOS) which was performed in patients with recurrent epiphora after failed external dacryocystorhinostomy(Ex-DCR) and analyze the causes of failed Ex-DCR.METHODS: From September 2015 and December 2017, the clinic data of 29 cases suffered from recurrent epiphora after failed Ex-DCR was reviewed.The LOS were implanted into the ostium at the end of the revisional surgery.The causes of failed Ex-DCR were analyzed before revisional surgeries.Outcome of revisional surgeries with the new device were evaluated as well.RESULTS: The major causes of failure of the external approach were synechiae formation in the nasal ostium(29/29), followed by inadequate removal of the bony wall(21/29), nasal synechiae formation between lateral wall of nose and middle turbinate(11/29), and the bone opening was not in good location(7/29).The rate of success after revisional surgery was 82.76%.Re-obstruction of the ostiums were found in 5 failed cases.CONCLUSION: Endoscopic approach with a novel LOS may be an effective procedure to manage recurrent epiphora after previous failed Ex-DCR surgery.Synechiae formation in the nasal ostium and inadequate removal of the bony wall were the major causes of failure of Ex-DCR.

Can the wet suction technique change the efficacy of endoscopic ultrasound-guided fine-needle aspiration for diagnosing autoimmune pancreatitis type 1? A prospective single-arm study

BACKGROUND Other than surgery,endoscopic ultrasound-guided fine-needle aspiration(EUSFNA)is the only procedure for histologically diagnosing autoimmune pancreatitis(AIP).However,adequate specimens are difficult to obtain.Recently,more adequate specimens were reported to be obtained with EUS-FNA with a wet suction technique(WEST)than with conventional EUS-FNA.AIM To histologically diagnose AIP by EUS-FNA with a WEST.METHODS Eleven patients with possible type 1 AIP between February 2016 and August 2018 underwent EUS-FNA with a WEST(WEST group),with four punctures by 19 or 22 G needles.As a historical control,23 type 1 AIP patients who underwent no fewer than four punctures with 19 or 22 G needles were enrolled(DRY group).Patient characteristics and histological findings were compared between the two groups.RESULTS Three histopathological factors according to the International Consensus Diagnostic Criteria were significantly greater in the WEST group than the DRY group[lymphoplasmacytic infiltrate without granulocytic infiltration:9(81.8%)vs 6(26.1%),P=0.003,storiform fibrosis:5(45.5%)vs 1(4.3%),P=0.008,abundant(>10 cells/HPF)IgG4-positive cells:7(63.6%)vs 5(21.7%),P=0.026].Level 1 or level 2 histopathological findings were observed more often in the WEST group than in the DRY group[8(72.7%)vs 3(13.0%),P=0.001].CONCLUSION EUS-FNA with a WEST was more successful than standard EUS-FNA in histologically diagnosing AIP.

Percutaneous endoscopic gastrostomy and jejunostomy:Indications and techniques

Nutritional support is essential in patients who have a limited capability to maintain their body weight.Therefore,oral feeding is the main approach for such patients.When physiological nutrition is not possible,positioning of a nasogastric,nasojejunal tube,or other percutaneous devices may be feasible alternatives.Creating a percutaneous endoscopic gastrostomy(PEG)is a suitable option to be evaluated for patients that need nutritional support for more than 4 wk.Many diseases require nutritional support by PEG,with neurological,oncological,and catabolic diseases being the most common.PEG can be performed endoscopically by various techniques,radiologically or surgically,with different outcomes and related adverse events(AEs).Moreover,some patients that need a PEG placement are fragile and are unable to express their will or sign a written informed consent.These conditions highlight many ethical problems that become difficult to manage as treatment progresses.The aim of this manuscript is to review all current endoscopic techniques for percutaneous access,their indications,postprocedural follow-up,and AEs.

Endoscopic therapy for early gastric cancer: Standard techniques and recent advances in ESD

The technique of endoscopic submucosal dissection(ESD)is now a well-known endoscopic therapy for early gastric cancer.ESD was introduced to resect large specimens of early gastric cancer in a single piece.ESD can provide precision of histologic diagnosis and can also reduce the recurrence rate.However,the drawback of ESD is its technical difficulty,and,consequently,it is associated with a high rate of complications,the need for advanced endoscopic techniques,and a lengthy procedure time.Various advances in the devices and techniques used for ESD have contributed to overcoming these drawbacks.

Endoscopic dilation of complete oesophageal obstructionswith a combined antegrade-retrograde rendezvoustechnique

AIM: To investigate the combined antegraderetrograde endoscopic rendezvous technique for complete oesophageal obstruction and the swallowing outcome.METHODS: This single-centre case series includes consecutive patients who were unable to swallow due to complete oesophageal obstruction and underwent combined antegrade-retrograde endoscopic dilation(CARD) within the last 10 years. The patients' demographic characteristics, clinical parameters, endoscopic therapy, adverse events, and outcomes were obtained retrospectively. Technical success was defined as effective restoration of oesophageal patency. Swallowing success was defined as either percutaneous endoscopic gastrostomy(PEG)-tube independency and/or relevant improvement of oral food intake, as assessed by the functional oral intake scale(FOIS)(≥ level 3).RESULTS: The cohort consisted of six patients [five males; mean age 71 years(range, 54-74)]. All but one patient had undergone radiotherapy for head and neck or oesophageal cancer. Technical success was achieved in five out of six patients. After discharge, repeated dilations were performed in all five patients. During follow-up(median 27 mo, range, 2-115), three patients remained PEG-tube dependent. Three of four patients achieved relevant improvement of swallowing(two patients: FOIS 6, one patient: FOIS 7). One patient developed mediastinal emphysema following CARD, without a need for surgery.CONCLUSION: The CARD technique is safe and a viable alternative to high-risk blind antegrade dilation in patients with complete proximal oesophageal obstruction. Although only half of the patients remained PEG-tube independent, the majority improved their ability to swallow.

Endoscopic shielding technique, a new method in therapeutic endoscopy

Prevention of late complications after large endoscopic resection is inefficient with current methods.Endoscopic shielding,as a simple and safe technique,has been proposed to improve the incidence of these events.Different methods,sheets or hydrogels,have showed proven efficacy in the prevention of late bleeding and perforation,as well as the improvement of tissue repair,in experimental models and in clinical practice.

New flexible endoscopic controlled stapler technique for the treatment of Zenker's diverticulum:A case series

AIM To report about the combination and advantages of a tapler-assisted diverticulotomy performed by flexible endoscopy.METHODS From November 2014 till December 2015 17 patients(8 female, 9 male, average age 69.8 years) with a symptomatic Zenker diverticulum(mean size 3.5 cm) were treated by inserting a new 5 mm fully rotatable surgical stapler(Micro Cutter30 Xchange, Cardica Inc.) next to an ultrathin flexible endoscope through an overtube. The Patients were under conscious sedation with the head reclined in left position, the stapler placed centrally and pushed forward to the bottom of the diverticulum. The septum was divided by the staple rows under flexible endoscopic control.RESULTS In eleven patients(64.7%) the stapler successfully divided the septum completely. Mean procedure time was 21 min, medium size of the septum was 2.8 cm(range 1.5 cm to 4 cm). In four patients the septum was shorter than 3 cm, in seven longer than 3 cm. To divide the septum, averagely 1.3 stapler cartridges were used. Two minor bleedings occurred. Major adverse events like perforation or secondary haemorrhage did not occur. After an average time of two days patients were discharged from the hospital. In 6 patients(35.3%) the stapler failed due to a thick septum or insufficient reclination of the head. Follow up endoscopy was performed after an average of two months in 9 patients; 4 patients(44.4%) were free of symptoms, 5 patients(55.6%) stated an improvement. A relapse of symptoms did not occur. CONCLUSION Flexible endoscopic Zenker diverticulotomy by using a surgical stapler is a new, safe and efficient treatment modality. A simultaneously tissue opening and occlusion prevents major complications.

Slow-pull and different conventional suction techniques in endoscopic ultrasound-guided fine-needle aspiration of pancreatic solid lesions using 22-gauge needles

AIM To evaluate the cytological diagnostic capacity and sample quality of the slow-pull technique and compare them with different suction techniques.METHODS From July 2010 to December 2015, 102 patients with pancreatic solid lesions who underwent endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA) with 22-gauge needles were retrospectively evaluated. EUS-FNA diagnosis was based on a cytological examination, and final diagnosis was based on a comprehensive standard of cytological diagnosis, surgical pathology and clinical or imaging follow-up. Cytological specimens were characterized for cellularity and blood contamination. The cytological diagnostic capacity and sample quality of the slow-pull technique and suction techniques with 5-m L/10-m L/20-m L syringes were analyzed.RESULTS Of all of the EUS-FNA procedures, the slow-pull technique and suction techniques with 5-m L/10-m L/20-m L syringes were used in 31, 19, 34 and 18 procedures, respectively. There were significant differences between these four suction techniques in terms of cytological diagnostic accuracy(90.3% vs 63.2% vs 58.8% vs 55.6%, P = 0.019), sensitivity(88.2% vs 41.7% vs 40.0% vs 36.4%, P = 0.009) and blood contamination(score ≥ 2 for 29.0% vs 52.6% vs 70.6% vs 72.2%, P = 0.003). The accuracy and sensitivity of the slow-pull technique were significantly higher than those of the suction techniques using 5-m L(P = 0.03, P = 0.014), 10-m L(P = 0.005; P = 0.006) and 20-mL syringes(P = 0.01, P = 0.01). Blood contamination was significantly lower in the slow-pull technique than in the suction techniques with 10-m L(P = 0.001) and 20-mL syringes(P = 0.007).CONCLUSION The slow-pull technique may increase the cytological diagnostic accuracy and sensitivity with slight blood contamination during EUS-FNA when using 22-gauge needles for solid pancreatic masses.

Advancements in endoscopic hemostasis for non-variceal upper gastrointestinal bleeding

Non-variceal upper gastrointestinal(GI)bleeding is a significant cause of morbidity and mortality.Traditionally,through-the-scope(TTS)clips,thermal therapy,and injection therapies are used to treat GI bleeding.In this review,we provide an overview of novel endoscopic treatments that can be used to achieve hemostasis.Specifically,we discuss the efficacy and applicability of over-thescope clips,hemostatic agents,TTS doppler ultrasound,and endoscopic ultrasound,each of which offer an effective method of reducing rates of GI rebleeding.