Offshoots of peroral endoscopic myotomy: Submucosal tunneling endoscopic resection,pyloromyotomy, and beyond

The emergence of peroral endoscopic myotomy (POEM) marks the rising of a new branch of therapeutic endoscopy. Our group defines it as tunnel endoscopic surgery that includes several novel procedures utilizing a submucosal tunnel as an operating space. In 2010, we developed a new procedure that takes advantage of the submucosal tunneling technique popularized by POEM to achieve complete, full-thickness endoscopic resection of upper gastrointestinal submucosal tumors originating from the muscularis propria layer. Our group coined the acronym STER (submucosal tunneling endoscopic resection) for this procedure. Herein, we summarize this novel method and other offshoots of POEM.     

Endoscopic treatment for chronic pancreatitis: indications, technique, results

Endoscopic treatment associated with or without extracorporeal shock wave lithotripsy (ESWL) for chronic pancreatitis has been employed for about 20 years. Although two randomized control trials have revealed the greater effectiveness of surgery as compared to endoscopic treatment for chronic pancreatitis, a considerable number of patients have successfully obtained complete and long-term relief from pain by the less invasive endoscopic treatment. In this review, we discuss the indications, techniques and results of endoscopic treatment and ESWL for painful chronic pancreatitis. We also discuss the characteristic clinical features that are predictive of a good response to endoscopic treatment and ESWL.     

Endoscopic full-thickness resection,indication, methods and perspectives

Minimally invasive surgery has emerged as the dominant theme of modern surgery, in which endoscopic surgery plays a key role. The technique of endoscopic surgery has evolved continuously with extensive research, improving the treatment modalities as well as expanding the indications for its use. As an active perforation endoscopic technique, endoscopic full-thickness resection (EFTR) is mainly used in the treatment of submucosal tumors (SMTs) of the gastrointestinal tract. With decades of evolution, EFTR has gradually developed into a mature endoscopic operation. Based on clinical experience and current research, indications, techniques, clinical outcomes and future perspectives for EFTR are discussed in this paper. We performed a bibliometric study on EFTR literature and showed robust data through a brief meta-analysis on the topic.     

A randomised controlled comparison of injection, thermal, and mechanical endoscopic methods of haemostasis on mesenteric vessels

Background and aims—A randomised controlledcomparison of haemostatic efficacy of mechanical, injection, andthermal methods of haemostasis was undertaken using canine mesentericvessels to test the hypothesis that mechanical methods of haemostasis are more effective in controlling haemorrhage than injection or thermalmethods. The diameter of arteries in human bleeding ulcers measures upto 3.45 mm; mesenteric vessels up to 5 mm were therefore studied.
Methods—Mesenteric vessels were randomised totreatment with injection sclerotherapy (adrenaline and ethanolamine),bipolar diathermy, or mechanical methods (band, clips, sewing machine, endoloops). The vessels were severed and haemostasis recorded.
Results—Injection sclerotherapy and clips failedto stop bleeding from vessels of 1 mm (n=20) and 2 mm (n=20). Bipolardiathermy was effective on 8/10 vessels of 2 mm but failed on 3 mmvessels (n=5). Unstretched elastic bands succeeded on 13/15 vessels of 2 mm but on only 3/10 vessels of 3 mm. The sewing machine achieved haemostasis on 8/10 vessels of 4 mm but failed on 5 mm vessels (n=5);endoloops were effective on all 5 mm vessels (n=5).
Conclusions—Only mechanical methods wereeffective on vessels greater than 2 mm in diameter. Some mechanicalmethods (banding and clips) were less effective than expected and needmodification. Thermal and (effective) mechanical methods weresignificantly (p<0.01) more effective than injection sclerotherapy.The most effective mechanical methods were significantly more effective (p<0.01) than thermal or injection on vessels greater than 2mm.

Keywords:endoscopic haemostasis; mesentericvessels

     

Benefits of endoscopic submucosal dissection according to size and location of gastric neoplasm, compared with conventional mucosal resection

Background and Aims:  To clarify optimal therapeutic strategies for early gastric cancers without vestigial remnant or recurrence, we evaluated the benefits of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) according to tumor size and location.
Methods:  From January 2000 to December 2007, a total of 328 gastric lesions were treated using conventional EMR, while 572 lesions were treated by ESD. Patients who underwent surgery on the upper gastrointestinal tract before EMR or ESD were excluded from the study. We compared tumor size, location and rates of complete resection, curative resection, postoperative bleeding, perforation and local recurrence between EMR and ESD according to tumor situation.
Results:  Overall local complete resection rate (EMR, 64.2%; ESD, 95.1%) and overall curative resection rate (EMR, 59.5%; ESD, 82.7%) were significantly higher in ESD than in EMR. No significant differences were seen in complication rates between EMR and ESD. Local recurrence was detected in 13 lesions (4.0%) of the EMR group during follow up. In contrast, no local recurrence was detected in the ESD group. For lesions 5 mm or less in diameter, complete resection rate in the EMR group was not significantly inferior to that in the ESD group at any location. However, rates were overwhelmingly better in the ESD group than in the EMR group for lesions more than 5 mm in diameter, regardless of location.
Conclusion:  We concluded that lesions exceeding 5 mm in diameter should be treated by ESD, although a high resection rate is obtained also with EMR for lesions of 5 mm or less in diameter.     

Suturing techniques with endoscopic clips and special devices after endoscopic resection

Endoscopic submucosal dissection is an established method for complete resection of large and early gastrointestinal tumors. However, methods to reduce bleeding, perforation, and other adverse events after endoscopic resection (ER) have not yet been defined. Mucosal defect closure is often performed endoscopically with a clip. Recently, reopenable clips and large-teeth clips have also been developed. The over-the-scope clip enables complete defect closure by withdrawing the endoscope once and attaching the clip. Other methods involve attaching the clip-line or a ring with an anchor to appose the edges of the mucosal defect, followed by the use of an additional clip for defect closure. Since clips are limited by their grasping force and size, other methods, such as endoloop closure, endoscopic ligation with O-ring closure, and the reopenable clip over-the-line method, have been developed. In recent years, techniques often utilized for full-thickness ER of submucosal tumors have been widely used in full-thickness defect closure. Specialized devices and techniques for defect closure have also been developed, including the curved needle and line, stitches, and an endoscopic tack and suture device. These clips and suture devices are applied for defect closure in emergency endoscopy, accidental perforations, and acute and chronic fistulas. Although endoscopic defect closure with clips has a high success rate, endoscopists need to simplify and promote endoscopic closure techniques to prevent adverse events after ER.     

Advanced endoscopic resection in the colon: recent innovations,current limitations and future directions

The major health burden of colorectal cancer is reduced by colonoscopic polypectomy. The majority of polyps encountered are diminutive in size and easily removed; however, endoscopic removal of lesions >20 mm in size is also effective and safe. Techniques have progressed, advancing the boundaries of endoscopic therapy to include resection of circumferential lesions and selected submucosal invasive cancers. While there are cost and safety advantages over surgical management, specific limitations of endoscopic resection remain, chiefly bleeding, perforation and recurrence. Recent studies highlight the utility of risk stratification and demonstrate the effectiveness of endoscopic treatment of complications; however, strategies for prevention remain elusive. Prediction of submucosal invasive cancers through systematic assessment of lesion morphology and surface pattern is now established. Harnessing submucosal invasive cancer prediction and risk stratification allows a shift toward lesion-specific therapy, the next paradigm in the management of advanced colonic lesions.     

Percutaneous Endoscopic Gastrostomy,Duodenostomy and Jejunostomy for Alimentation in Gastrectomized Patients

Percutaneous Endoscopic Gastrostomy (PEG) which can be accomplished with local anesthesia and without the necessity for laparotomy is now gaining popularity as a clinical treatment for patients who have difficulties in swallowing and require long term nutritional support but have an intact gut. A total of 40 patients underwent percutaneous endoscopic placement of a feeding tube in our clinic. They included 37 patients who had had PEG, 1 Percutaneous Endoscopic Duodenostomy (PED) and 2 Percutaneous Endoscopic Jejunostomy (PEJ). Of these patients, 3 had previously had a partial gastrectomy and 1 had had an esophagectomy with esophago-jejunostomy. Three patients who had undergone a previous partial gastrectomy received different procedures; 1 PEG, 1 PED and 1 PEJ, which were considered to be most appropriate for each patient. One patient with a previous esophagectomy had a PEJ. PEG, PED and PEJ for the patients who had previously undergone a gastrectomy were successfully done with great care. Our experience suggests that PEG, PED or PEJ are rapid, safe and useful procedures for patients who are a poor anesthetic or poor operative risk and can be used even for patients who have undergone previous surgery.     

Evolving endoscopic surgery

Since the days of Albukasim in medieval Spain, natural orifices have been regarded not only as a rather repugnant source of bodily odors, fluids and excreta, but also as a convenient invitation to explore and treat the inner passages of the organism. However, surgical ingenuity needed to be matched by appropriate tools and devices. Lack of technologically advanced instrumentation was a strong deterrent during almost a millennium until recent decades when a quantum jump materialized. Endoscopic surgery is currently a vibrant and growing subspecialty, which successfully handles millions of patients every year. Additional opportunities lie ahead which might benefit millions more, however, requiring even more sophisticated apparatuses, particularly in the field of robotics, artificial intelligence, and tissue repair (surgical suturing). This is a particularly exciting and worthwhile challenge, namely of larger and safer endoscopic interventions, followed by seamless and scarless recovery. In synthesis, the future is widely open for those who use together intelligence and creativity to develop new prototypes, new accessories and new techniques. Yet there are many challenges in the path of endoscopic surgery. In this new era of robotic endoscopy, one will likely need a virtual simulator to train and assess the performance of younger doctors. More evidence will be essential in multiple evolving fields, particularly to elucidate whether more ambitious and complex pathways, such as intrathoracic and intraperitoneal surgery via natural orifice transluminal endoscopic surgery (NOTES), are superior or not to conventional techniques.     

Colorectal endoscopic submucosal dissection: present status and future perspective,including its differentiation from endoscopic mucosal resection

Endoscopic submucosal dissection (ESD) allows en bloc resection of a lesion, irrespective of the size of the lesion. ESD has been established as a standard method for the endoscopic ablation of malignant tumors in the upper gastrointestinal (GI) tract in Japan. Although the use of ESD for colorectal lesions has been studied via clinical research, ESD is not yet established as a standard therapeutic method for colorectal lesions because colorectal carcinoma has unique pathological, organ specific characteristics that differ radically from those of the esophagus and stomach, and scope handling and control is more difficult in the colorectum than in the upper GI tract. Depending on the efficacy of endoscopic mucosal resection (EMR) and the clinicopathological characteristics of the colorectal tumor, the proposed indications for colorectal ESD are as follows: (1) lesions difficult to remove en bloc with a snare EMR, such as nongranular laterally spreading tumors (particularly the pseudo depressed type), lesions showing a type VI: pit pattern, and large lesions of the protruded type suspected to be carcinoma; (2) lesions with fibrosis due to biopsy or peristasis; (3) sporadic localized lesions in chronic inflammation such as ulcerative colitis; and (4) local residual carcinoma after EMR. Colorectal ESD is currently in the development stage, and a standard protocol will be available in the near future. We hope that colorectal tumors will be efficiently treated by a treatment method appropriately selected from among EMR, ESD, and surgical resection after precise preoperative diagnosis based on techniques such as magnifying colonoscopy.     

RISK MANAGEMENT OF THERAPEUTIC COLONOSCOPY (HOT BIOPSY,POLYPECTOMY, ENDOSCOPIC MUCOSAL RESECTION AND ENDOSCOPIC SUBMUCOSAL DISSECTION)

The concept of an adenoma–carcinoma sequence has been widely accepted in the colon and rectum, contrary to that in gastric cancer. Consequently, most target lesions for endoscopic resection using these newly developed techniques are histologically assessed as adenoma or intramucosal carcinoma in adenoma. Based on results in conventional endoscopic mucosal resection (EMR), almost all remnant or recurrent tumors can be successfully managed by salvage EMR, and all materials resected by salvage EMR also showed adenoma or intramucosal cancer. These results suggest that en bloc resection is not always clinically necessary to obtain complete cure for all colorectal neoplasia. However, larger lesions tend to be resected in a piecemeal fashion; it is difficult to confirm whether EMR has been completed or not. For precise histopathological assessment of the resected specimen, endoscopic submucosal dissection (ESD) for en bloc resection is desirable, although further experience is needed to establish its safety and efficacy. The present review contains a summary of the risk management of therapeutic colonoscopy including ESD for large colorectal mucosal neoplasia, debated at the Endoscopic Forum Japan 2006, Hakone, and discussion of the problems and future prospects of these procedures.     

CURRENT STATUS AND FUTURE EXPECTATIONS FOR ENDOSCOPIC BILIARY DRAINAGE IN 16 HOSPITALS

The authors examined the performance of endoscopic biliary drainage (EBD) in 16 hospitals. The examination was in the form of a questionnaire given between 1 June and 20 July 2005 to clarify the status of 369 patients who had undergone EBD. A total of 124 patients underwent endoscopic nasobiliary drainage (ENBD), 224 patients underwent endoscopic biliary drainage (EBS), and one patient underwent simultaneous ENBD and EBS. With regard to the underlying diseases, 227 patients had malignant disease and 142 had benign disease. A total of 244 patients underwent EBS. Plastic stent (PS) was used in 200 cases, and metal stent (MS) in 44 cases. One stent was used in 89% of cases, two stents in 10%, three or more stents in 1%. Metal stent was used in 44 patients (23 were covered and 21 uncovered) with unresectable biliary stenosis. One stent was used in 33 patients, two stents in 10 patients, and three stents in one patient. For treating middle and inferior common bile duct stenosis, PS having a caliber of 10 Fr is too soft; newer tubes should be developed utilizing materials that provide longer stent patency. Longer patency can be achieved now by applying EBS using a covered MS. Improving the materials will also improve stent flexibility and the smoothness of the coating film. When treating superior common bile duct and porta hepatic bile duct stenosis, the stent is placed in both lobes of the liver.