En bloc endoscopic submucosal dissection of a 14-cm laterally spreading adenoma of the rectum with involvement to the anal canal: expanding the frontiers of endoscopic surgery (with video)

Efficacy and safety of MC-003 solution for endoscopic mucosal or submucosal resection: a prospective, multicenter, randomized, triple-blinded, parallel-group, phase III study

BACKGROUND AND AIMS

The safety and efficacy of solutions for submucosal injection are critical for endoscopic resection of gastric adenomas or early gastric cancers. Although several injectable solutions have been introduced for endoscopic resection, they have some limitations. We aimed to compare the efficacy of the new sodium alginate-based solution MC-003 with that of normal saline (NS; 0.9% sodium chloride).

METHODS

In this randomized, triple-blind study, 70 patients were initially enrolled for EMR or endoscopic submucosal dissection (ESD). The main outcomes included the need for additional injections, completion of en bloc resection, and occurrence of adverse events.

RESULTS

Each group ultimately included 34 patients. Complete en bloc resections were achieved in all patients (P = 1.000). The MC-003 group had more peri-neoplasm tissue fibrosis (P = .056) and needed fewer additional injections for lesions >15 mm (P = .037), located in the distal portion of the stomach (P = .007), and during ESD procedures (P = .001). The adverse event rate was comparable in both groups.

CONCLUSIONS

MC-003 outperformed NS in reducing the need for additional injections during en bloc resection, particularly in larger lesions located in the distal portion of the stomach (where most lesions were found) during ESD procedures, without increasing the incidence of serious adverse events. MC-003 is a promising submucosal injectable solution in real-world clinical settings.

Transanal Endoscopic Microsurgical Submucosal Dissection: An Efficient Treatment Option for Giant Superficial Neoplastic Lesions of the Rectum

Introduction

The resection of giant superficial neoplastic lesions of the rectum (>5 cm) is challenging even for experienced specialists. Endoscopic mucosal resection, endoscopic submucosal dissection (ESD), and transanal endoscopic microsurgery (TEM) have all been used for the treatment of such tumors. However, because of their individual disadvantages, the ideal technique for the treatment of these lesions has yet to be determined. Transanal endoscopic microsurgical submucosal dissection (TEM-ESD) is a recently developed hybrid technique that combines the advantages of conventional TEM and flexible ESD. The aim of our study was to assess the feasibility and outcomes of TEM-ESD for the resection of giant superficial rectal neoplasms.

Methods

We retrospectively analyzed all cases of TEM-ESD performed in the Department of Surgery of the Municipal Hospital of Karlsruhe between 2010 and 2020 and isolated 43 patients with superficial rectal lesions >5 cm according to the postoperative histology report. The diagnostic, perioperative, histological, and follow-up data of the patients were analyzed in the form of a retrospective, observational cohort study.

Results

We identified 43 cases matching our criteria, including 35 adenomas and 8 occult adenocarcinomas. The median size of the lesions was 75 mm and the median operating time was 81.5 min. En bloc resection was possible in all cases, and histologically complete en bloc resection was confirmed in 29 cases. Five patients presented with postoperative bleeding, 2 of which were treated conservatively, 2 were treated endoscopically, and 1 required revision surgery. The median follow-up period was 15 months. There was no recurrence among patients with adenomas, 1 recurrence of a low-risk carcinoma, and 1 recurrence after the resection of a high-risk carcinoma in a patient that refused further treatment. During the follow-up period, 3 patients developed a stenosis, which was treated endoscopically.

Conclusions

TEM-ESD is a feasible and safe therapeutic option for the treatment of giant superficial rectal neoplasms.

Efficacy and Safety of Endoscopic Submucosal Dissection for Rectal Tumors Extending Versus Not to the Dentate Line: A Systematic Review and Meta-Analysis

GOALS

To evaluate the outcomes of endoscopic submucosal dissection (ESD) for rectal tumors extending to the dentate line (RTDLs) compared with rectal tumors not extending to the dentate line (non-RTDLs).

BACKGROUND

There is limited composite data on the outcomes of ESD for RTDLs versus non-RTDLs.

STUDY

We performed a systematic review and meta-analysis of studies that reported the clinical outcomes of ESD for RTDLs and non-RTDLs. Main outcomes were pooled estimated rates of en bloc/complete/curative resection, local recurrence, and incidence of bleeding, perforation, stricture, anal pain, and fever.

RESULTS

Six studies were enrolled, including 265 cases of RTDLs and 788 cases of non-RTDLs. The en bloc resection rate was comparable for RTDLs and non-RTDLs [odds ratio (OR), 1.04; 95% confidence interval (CI), 0.55-1.95; P=0.90]. The complete resection rate was significantly lower for RTDLs (OR, 0.59; 95% CI, 0.41-0.83; P=0.003), as well as the curative resection rate (OR, 0.57; 95% CI, 0.38-0.87; P=0.010). The rates of stricture, postoperative anal pain and local recurrence were significantly higher for RTDLs than non-RTDLs (OR, 3.07; 95% CI, 1.01-9.31; P=0.05) (OR, 42.10; 95% CI, 4.73-374.97; P=0.0008) (OR, 3.00; 95% CI, 1.13-7.96; P=0.03), but the higher rates of postoperative bleeding and fever for RTDLs were not significantly (OR, 1.33; 95% CI, 0.53-3.30; P=0.54) (OR, 2.23; 95% CI, 0.55-9.07; P=0.26), as well as its lower perforation rate (OR, 0.85; 95% CI, 0.27-2.63; P=0.78).

CONCLUSIONS

Despite its inferior outcomes than non-RTDLs, ESD is still a feasible and safe treatment for RTDLs if appropriate lesions are treated by experienced operators.

The feasibility of endoscopic submucosal dissection for colorectal lesions larger than 10 cm

BACKGROUND

Although endoscopic submucosal dissection (ESD) enables en bloc removal of colorectal neoplasms, its effectiveness for larger lesions (≥ 10 cm in diameter) is undetermined. We aimed to investigate the feasibility and safety of ESD for colorectal lesions ≥ 10 cm wide.

METHODS

This retrospective study included 3591 consecutive colorectal lesions managed with ESD from June 2012 through December 2020. Clinicopathological characteristics and treatment outcomes were compared between lesions ≥ 10 cm wide and lesions 5-10 cm wide.

RESULTS

There were 50 patients in the ≥ 10 cm group and 270 patients in the 5-10 cm group. Among patients in the ≥ 10 cm group, lesions were most often in the rectum (50.0%), and the laterally spreading tumor-granular nodular mixed type (LST-G-M) was most prevalent (41/50, 82%). Although patients in the ≥ 10 cm group a longer mean ESD procedure time (186.0 vs. 94.4 min, p < 0.001), the dissection speed was significantly higher in this group (0.50 vs. 0.41 cm²/min, p = 0.003). The en bloc and curative resection rates were comparable between the ≥ 10 cm and 5-10 cm groups (100% vs. 99.6% and 86.0% vs. 88.5%, respectively). Although the stenosis rate was higher in the ≥ 10 cm group (4% vs. 0%), the delayed bleeding and perforation rates were similar between the two groups.

CONCLUSIONS

ESD for colorectal lesions ≥ 10 cm wide is feasible and curative, even though it is associated with higher technical difficulty and longer procedure times compared with ESD for smaller lesions (Number: UMIN 000044313).

Review on colorectal endoscopic submucosal dissection focusing on the technical aspect

BACKGROUND

Endoscopic submucosal dissection (ESD) enables removal of broad-based colorectal polyps or lateral spreading tumors with a higher rate of en bloc resection and a lower risk of local recurrence. However, it is technically demanding. Over the past 20 years, various equipment and innovative techniques have been developed to reduce the difficulty of ESD. The information in the literature is scattered. Our aim is to provide a comprehensive review on the setup and technical aspects of colorectal ESD.

METHODS

We searched the PubMed database and systemically reviewed all original and review articles related to colorectal ESD. Further manual search according to reference lists of identified articles were done. The selected articles were categorized and reviewed. Original figures were created to help readers understand some of the ESD techniques.

RESULTS

A total of 216 articles were identified, in which 25 of them were review articles and 191 of them were original articles. They were categorized and reviewed. An in-depth appraisal of the setting, equipment, and technical aspects of colorectal ESD was performed.

CONCLUSIONS

Although ESD is a technically demanding procedure that requires expert endoscopic skills, it can be mastered. With good peri-procedural preparation, sufficient knowledge of the equipment, and thorough understanding of the useful endoscopic tricks and maneuvers, colorectal ESD can be performed smoothly and safely.

Endoscopic submucosal dissection involving the anal canal presents a risk factor for postoperative stricture

BACKGROUND

Although postoperative strictures after endoscopic submucosal dissection (ESD) in the rectum are relatively rare, some rectal lesions require resection involving the anal canal, which is a narrow tract comprising squamous epithelium. To the best of our knowledge, no studies have investigated narrow anal canals when evaluating post-ESD strictures. This study aimed to evaluate the impact of resections involving the anal canal on postoperative stricture development.

METHODS

Between April 2005 and October 2017, 707 rectal lesions were treated with ESD. We retrospectively investigated 102 lesions that required ≥ 75% circumferential resection. Risk factors for post-ESD stricture and, among patients with strictures, obstructive symptoms, and number of dilation therapies required were investigated.

RESULTS

Post-ESD stricture occurred in 18 of 102 patients (17.6%). In the multivariate analysis, circumferential resection ≥ 90% and ESD involving the anal canal (ESD-IAC) were risk factors for postoperative strictures (P ≤ 0.0001 and 0.0115, respectively). Among the patients with strictures, obstructive symptoms were significantly related to anal strictures compared to rectal strictures (100% vs. 27.2%, P = 0.0041). Furthermore, the number of dilation therapies required was significantly greater among patients with anal strictures compared to those with rectal strictures (6.5 times vs. 2.7 times, P = 0.0263).

CONCLUSION

Not only circumferential resection ≥ 90% but also ESD-IAC was a significant risk factor for the stricture after rectal ESD. Furthermore, anal strictures were associated with a significantly higher frequency of obstructive symptoms and larger number of required dilation therapies than were rectal strictures.

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.

Safe and Effective Endoscopic Resection of Massive Colorectal Adenomas ≥8 cm in a Tertiary Referral Center

BACKGROUND

Endoscopic resection of large colorectal lesions is well reported and is the first line of treatment for all noninvasive colorectal neoplasms in many centers, but little is known about the outcomes of endoscopic resection of truly massive colorectal lesions ≥8 cm.

OBJECTIVE

We report on the outcomes of endoscopic resection for massive (≥8 cm) colorectal adenomas and compare the outcomes with resection of large (2.0-7.9 cm) lesions.

DESIGN

This was a retrospective study.

SETTINGS

The study was conducted in a tertiary referral unit for interventional endoscopy.

PATIENTS

A total of 435 endoscopic resections of large colorectal polyps (≥2 cm) were included, of which 96 were ≥8 cm.

MAIN OUTCOME MEASURES

Outcomes included initial successful resection, complications, recurrence, surgery, and hospital admission.

RESULTS

Endoscopic resection was successful for 91 of 96 massive lesions (≥8 cm). Mean size was 10.1 cm (range, 8-16 cm). A total of 75% had previous attempts at resection or heavy manipulation before referral. Thirty two were resected using endoscopic submucosal dissection or hybrid endoscopic submucosal dissection and the rest using piecemeal endoscopic mucosal resection. No patients required surgery for a perforation. Five patients had postprocedural bleeding. There were 25 recurrences: 2 were treated with transanal endoscopic microsurgery, 2 with right hemicolectomy, and the rest with endoscopic resection. Compared with patients with large lesions, more patients with massive adenomas had complications (19.8% versus 3.3%), required admission (39.6% versus 11.0%), developed recurrence (30.8% versus 9.9%), or required surgery for recurrence (5.0% versus 0.8%).

LIMITATIONS

This was a retrospective study.

CONCLUSIONS

Endoscopic resection of massive colorectal adenomas ≥8 cm is achievable with few significant complications, and the majority of patients avoid surgery. Systematic assessment is required to appropriately select patients for endoscopic resection, which should be performed in specialist units. See Video Abstract at http://links.lww.com/DCR/A653.

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.

Colorectal endoscopic submucosal dissection: patient selection and special considerations

Endoscopic submucosal dissection (ESD) enables en bloc resection of large complex colorectal superficial neoplastic lesions, resulting in very low rates of local recurrence, high-quality pathologic specimens for accurate histopathologic diagnosis and potentially curative treatment of early adenocarcinoma without resorting to major surgical resection. The safety and efficacy of the technique, which was pioneered in the upper gastrointestinal tract, has been established by the consistently impressive outcomes from expert centers in Japan and some other eastern countries. However, ESD is challenging to perform in the colorectum and there is a significant risk of complications, particularly in the early stages of the learning curve. Early studies from western centers raised concerns about the high complication rates, and the impressive results from Japanese centers were not replicated. As a result, many western endoscopists are skeptical about the role of ESD and few centers have incorporated the technique into their practice. Nevertheless, although the distribution of expertise, referral centers and modes of practice may differ in Japan and western countries, ESD has an important role and can be safely and effectively incorporated into western practice. Key to achieving this is meticulous lesion assessment and selection, appropriate referral to centers with the necessary expertise and experience and application of the appropriate technique individualized to the patient. This review discusses the advantages, risks and benefits of ESD to treat colorectal lesions and the importance of preprocedure lesion assessment and in vivo diagnosis and outlines a pragmatic rationale for appropriate lesion selection as well as the patient, technical and institutional factors that should be considered.

The efficacy of endoscopic submucosal dissection for colorectal tumors extending to the dentate line

PURPOSE

Although endoscopic submucosal dissection (ESD) is becoming the mainstay of the treatment strategies, rather than surgical treatment, for colorectal tumors extending to the dentate line, ESD is technically more difficult. This study was aimed at assessing the usefulness of ESD for the treatment of colorectal tumors extending to the dentate line.

METHODS

This study included 531 patients with colorectal tumors who underwent colorectal ESD between 2008 and 2015. They were divided into three groups: rectal tumors extending to the dentate line (anorectal group), those not extending to the dentate line (proximal rectal group), and colonic tumors (colonic group), and a retrospective comparative analysis was carried out.

RESULTS

Of the total patients, 18 (3.4%) had lesions extending to the dentate line area. The procedure times were 103.4 ± 84.0, 80.4 ± 64.3, and 71.8 ± 52.3 min, respectively (P = 0.0318). All the patients in the anorectal group were operated by operators who had performed at least 20 colorectal ESDs (P < 0.0001). No significant difference among the three groups was found in the en bloc resection rate, complete resection rate, or curative resection rate. Although no significant difference in the incidence of perforation was observed among the three groups, intraoperative bleeding was observed in 61% of the patients in the anorectal group (P < 0.0001).

CONCLUSIONS

ESD is an effective treatment strategy for colorectal tumors extending to the dentate line. However, it seems that anorectal ESD, which is technically more difficult than colorectal ESD, should be performed by operators with ample experience in performing ESD.

Endoscopic submucosal dissection for laterally spreading tumors involving the appendiceal orifice

BACKGROUND

Since the endoscopic resection of laterally spreading tumors (LSTs) involving the appendiceal orifice remains technically difficult, such lesions are usually treated by surgical resection. However, with recent advances in endoscopic devices, endoscopic submucosal dissection (ESD) has become feasible and may be safely performed even for lesions involving the appendiceal orifice. Therefore, in order to assess the validity of endoscopic treatment for such lesions, we retrospectively evaluated the safety and efficacy of ESD.

METHODS

A total of 30 patients with LSTs extending to within 10 mm of the appendiceal orifice (Group AO) and 122 patients with cecal LSTs located away from the appendiceal orifice (Group C) who were treated between December 2011 and September 2015 were retrospectively enrolled in the present study. The indications for ESD were determined by the preoperative endoscopic diagnosis made on the basis of Kudo's pit pattern classification. Based on these preoperative endoscopic diagnoses, 8 of the 30 enrolled patients underwent surgical resection as the initial treatment, because the tumor showed deep invasion beyond the orifice and/or a VN pit pattern was visible. The treatment outcomes (en bloc R0 resection rates, tumor size, procedure time, and complication rates) were compared between the two groups.

RESULTS

The sensitivity and specificity for the cancer diagnosis were 81.8 and 94.7%, respectively. There was no significant difference in the en bloc R0 resection rate between Group AO and Group C (90.9 vs. 95.9%, P = 0.23). Furthermore, there were also no differences in the mean tumor size (30.0 ± 20.8 vs. 34.9 ± 14.5 mm, P = 0.17) or mean OR time (55.0 ± 39.2 vs. 58.9 ± 48.2 min P = 0.72) between the two groups. One case from Group AO (4.5%) was complicated by a perforation, which was successfully managed endoscopically.

CONCLUSIONS

Although proficiency in endoscopic techniques is required, our results indicate that LSTs involving the appendiceal orifice can be successfully treated by ESD.

Endoscopic submucosal dissection for anorectal tumor with hemorrhoids close to the dentate line: a multicenter study of Hiroshima GI Endoscopy Study Group

BACKGROUND

The lower rectum close to the dentate line has distinct characteristics, making endoscopic submucosal dissection (ESD) of tumors challenging. We assessed clinical outcomes of ESD for such patients with hemorrhoids.

METHODS

Sixty-four patients (mean age, 68 years) underwent ESD for anorectal tumors close to the dentate line. We divided patients into those with (Group A, 45 patients) and without hemorrhoids (Group B, 19 patients). We examined en bloc and histological en bloc resection rates, procedure time, complication rates, and postoperative prognosis after ESD.

RESULTS

The mean tumor size was 43 mm. Histologic diagnoses were adenoma (42 %, 27/64), carcinoma in situ (44 %, 28/64), and T1 carcinoma (14 %, 9/64). There was no significant difference in en bloc resection (93 %, 42/45 vs. 95 %, 18/19) or postoperative bleeding rates (16 %, 7/45 vs. 11 %, 2/19) between Groups A and B, respectively. The mean procedural durations were 120 and 124 min, respectively, in Groups A and B. No perforations occurred. There was no significant difference in postoperative anal pain rate between Groups A (18 %, 8/45) and B (16 %, 3/19), and it resolved within a few days in all cases. There was one case of stricture in Group B. Two patients with T1 carcinoma underwent additional surgery, one underwent chemotherapy, and five had no additional treatment. No recurrence occurred during the follow-up period of 38 months.

CONCLUSIONS

ESD is safe and effective for anorectal tumors close to the dentate line in patients with hemorrhoids.

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.

Endoscopic submucosal dissection versus local excision for early rectal cancer: a systematic review and meta-analysis

Endoscopic submucosal dissection (ESD) and local excision (LE) are minimally invasive procedures that can be used to treat early rectal cancer. There are no current guidelines or consensus on the optimal treatment strategy for these lesions. A systematic review was conducted to compare the efficacy and safety of ESD and LE. A meta-analysis was conducted following all aspects of the Cochrane Handbook for systematic reviews and preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement. To perform the statistical analysis, the odds ratio (OR) was used for categorical variables and the weighted mean difference (WMD) for continuous variables. Four studies, involving a total of 307 patients, were identified. The length of hospital stay was longer in the group of patients undergoing LE [weighted mean difference (WMD) -1.94; 95% CI -2.85 to -1.02; p < 0.0001]. The combined results of the individual studies showed no significant differences as regards en-bloc resection rate (OR 0.82; 95% CI 0.25-2.70; p = 0.74), R0 resection rate (OR 1.53; 95% CI 0.62-3.73; p = 0.35), overall complication rate (OR 0.67; 95% CI 0.26-1.69; p = 0.40), and tumor size (WMD 0.57; 95% CI -3.64 to 4.78; p = 0.79) between ESD and LE. When adopting the fixed effect model which takes into account the study size, ESD was associated with a lower recurrence rate than LE (OR 0.15; 95% CI 0.03-0.87; p = 0.03), while with the random-effect model the difference was not significant (OR 0.18; 95% CI 0.02-2.04; p = 0.17). Over the last decade improvements in technology have improved the technical feasibility of rectal ESD. In specialized centers with highly experienced endoscopists, ESD can provide high-quality en-bloc excision of rectal neoplasms equivalent to traditional local excision.

Complete Endoscopic Submucosal Dissection of a Giant Rectal Villous Adenocarcinoma with Electrolyte Depletion Syndrome

An 81-year-old female consulted a local physician due to diarrhea. Since general fatigue and body weight loss were observed, she was admitted for detailed examination and treatment. Colonoscopy revealed a circumferential giant tumor with a maximum diameter of 10 cm in the rectum, and biopsy findings indicated villous adenoma. The tumor secreted a large amount of mucus, and a diagnosis of electrolyte depletion syndrome causing electrolyte disorders was made. We performed endoscopic submucosal dissection (ESD) as a less invasive procedure. The tumor was so big that the procedure had to be completed in two separate steps and it took 1,381 min in total. The tumor was histologically diagnosed as well-differentiated adenocarcinoma in high-grade adenoma located in the lower to upper rectum, invading into the mucosa without lymphatic or venous invasion. The stump of the resected specimen was negative for adenocarcinoma, however the horizontal stump was positive for adenoma. We administered steroid suppositories to prevent stenosis. After ESD, general fatigue and diarrhea disappeared and electrolyte disorders resolved. The patient had good clinical outcome without recurrence or stenosis.

Hospital volume and the occurrence of bleeding and perforation after colorectal endoscopic submucosal dissection: analysis of a national administrative database in Japan

BACKGROUND

Colorectal endoscopic submucosal dissection has gained popularity as a minimally invasive technique for the treatment of colorectal neoplasms in many countries, including Japan. However, most previous studies of endoscopic submucosal dissection had relatively small sample sizes and only included patients treated at specialized centers. Associations between hospital volume and complication rates after colorectal endoscopic submucosal dissection are still poorly understood.

OBJECTIVE

Our aim was to clarify the relationships between hospital volume and the occurrence rates of bleeding and perforation after colorectal endoscopic submucosal dissection.

DESIGN

This was a retrospective cohort study. Hospital volume was defined as the number of colorectal endoscopic submucosal dissections performed at each hospital between April 2012 and March 2013 and was categorized into the following quartiles: 1) very low-volume (18 or less patients during the year), 2) low-volume (19-35 patients), 3) high-volume (36-58 patients), and 4) very high-volume (59 or more).

SETTINGS

This study was based on a national inpatient data from the Japanese Diagnosis Procedure Combination database.

PATIENTS

A total of 7567 patients with colorectal endoscopic submucosal dissection were included.

MAIN OUTCOME MEASURES

Severe postoperative bleeding requiring endoscopic hemostasis or blood transfusion within 1 week after endoscopic submucosal dissection and perforation requiring open surgery were the main outcomes measured.

RESULTS

Severe postoperative bleeding and perforation occurred in 331 (4.4%) and 13 patients (0.2%). Multivariable logistic regression analysis showed that the very high hospital volume group had a significantly lower proportion of severe postoperative bleeding than the very low hospital volume group (OR = 0.48 [95 % CI, 0.27-0.83]; p = 0.009).

LIMITATIONS

This study lacked some information on clinicopathologic features including en bloc resection, curative resection, and relapse. Individual endoscopist experience could not be analyzed.

CONCLUSIONS

The present study clearly showed a significant association between higher hospital volume and lower occurrence of severe postoperative bleeding.

Endoscopic submucosal dissection for colorectal lateral spreading tumors larger than 10 cm: is it feasible?

BACKGROUND

Colorectal endoscopic submucosal dissection (ESD) was applied to lesions, such as giant colorectal lateral spreading tumors (LSTs) > 10 cm, by an expert ESD endoscopist despite several limitations, such as a relatively high perforation rate and high technical difficulty.

OBJECTIVE

To investigate the feasibility and safety of ESD for giant colorectal LSTs ≥ 10 cm.

DESIGN

Retrospective study.

SETTING

Tertiary-care center.

PATIENTS

A total of 163 patients underwent colorectal ESD between 2009 and 2014 by a single expert ESD endoscopist at Gangnam Severance Hospital, Seoul, Korea. Among them, 9 patients had giant colorectal LSTs ≥ 10 cm.

INTERVENTIONS

Review of records.

MAIN OUTCOME MEASUREMENTS

Clinicopathologic factors and oncologic outcome associated with ESD between giant colorectal LSTs and others.

RESULTS

Colorectal LSTs ≥ 10 cm were classified as giant colorectal LSTs. Nine giant colorectal LST lesions were localized to the following regions: descending colon (n = 1), sigmoid colon (n = 1), and rectum (n = 7). The average maximal diameter of giant colorectal LSTs was 120.8 mm, and the procedure time was 270.0 minutes. Two lesions were of the whole nodular type, and 7 were focal nodular lesions. The en bloc and curative resection rates for ESD for giant colorectal LSTs were 88.9% and 100%, respectively. The adverse event rate was 44.4%. No strictures, local recurrences, or distant metastases occurred over a mean follow-up period of 27.1 months.

LIMITATIONS

Retrospective, single-center study.

CONCLUSIONS

ESD of giant colorectal LSTs appears to be a feasible and curative treatment, even though it is associated with a higher adverse event rate, higher degree of technical difficulty, and longer procedure time.

Expanding indications for ESD: mucosal disease (upper and lower gastrointestinal tract)

Endoscopic resection is now considered a curative procedure for early gastric cancer. In Japan, it has increasingly replaced surgical resection for this indication, although in the West it has not been universally accepted as a first-line treatment. Recently, endoscopic submucosal dissection has been increasingly applied to colorectal disease, although it has not become a standard therapeutic procedure for early colorectal carcinoma because of its technical difficulty, the relatively long procedure time required, and the risk of complications, such as perforation and bleeding.

Colorectal ESD: current indications and latest technical advances

The number of medical facilities that perform colorectal endoscopic submucosal dissection (ESD) has been growing, and its effectiveness has been increasingly reported in recent years. Indications approved by the Japanese government's medical insurance system are early colorectal cancers with a maximum tumor size of 2-5 cm. ESD was an effective procedure for treating noninvasive colorectal tumors difficult to resect en bloc by conventional EMR, resulting in a higher en bloc resection rate that is less invasive than surgery. Based on the excellent clinical results of colorectal ESDs, the Japanese health care insurance system has approved colorectal ESD for coverage.

Colorectal endoscopic submucosal dissection: Technical advantages compared to endoscopic mucosal resection and minimally invasive surgery

BACKGROUND AND AIM

In recent years, the effectiveness of colorectal endoscopic submucosal dissection (ESD) has been increasingly reported. Herein, we highlight the most recent developments and technical advantages of colorectal ESD compared to EMR and minimally invasive surgery.

METHODS

All candidate lesions for ESD were confirmed as being intramucosal tumors by colonoscopy. Presently, the indications for colorectal ESD approved by the Japanese government's medical insurance system are early colorectal cancers with a maximum tumor size of 2-5 cm; however, many early cancers >5 cm have been treated by ESD in referral centers.

RESULTS

The primary advantage of ESD compared to endoscopic mucosal resection (EMR) is a higher en-bloc resection rate for large colonic tumors that had previously been treated by surgery. ESD has several advantages compared to other therapeutic modalities, such as being a safer technique and providing better quality of life. For rectal cancer treatment, a longer procedure time is required for laparoscopic assisted colectomy, whereas trans-anal resection and trans-anal endoscopic microsurgery are more invasive than ESD with a significantly higher recurrence rate. Accordingly, ESD is the preferred choice for early colorectal cancers when there is no risk of lymph-node metastasis.

CONCLUSION

ESD is an effective procedure for treating non-invasive non-polypoid colorectal tumors. These tumors may be difficult to resect en bloc by conventional EMR. The use of ESD results in a higher en-bloc resection rate and is less invasive than surgery.

Successful endoscopic strategies for difficult polypectomy

PURPOSE OF REVIEW

Standard endoscopic polypectomy is a powerful technique to remove most polyps found in the gastrointestinal tract. However, a small percentage of polyps can be classified as difficult, based on size, location, and/or configuration. Traditionally, these difficult polyps were referred for surgical segmental colectomy. Recently, with advancements in endoscopic techniques and accessories, a majority of these difficult polyps are now able to be completely resected using entirely endoscopic techniques.

RECENT FINDINGS

Endoscopic techniques and accessories have been evolving during recent years, including increased dissemination of techniques of endoscopic submucosal dissection to the western hemisphere. In addition to refinement of endoscopic techniques, there has been increased interest in developing improved endoscopic accessories, including novel submucosal injectate with auto-dissecting properties, to improve safety and efficiency of endoscopic resection of difficult polyps.

SUMMARY

This article will review currently available techniques and strategies for successful endoscopic resection for difficult polyps.

Current status of endoscopic resection strategy for large, early colorectal neoplasia in Japan

BACKGROUND

Conventional endoscopic resection (CER) for early colorectal neoplasia (CRN) is widely accepted as a minimally invasive treatment. Endoscopic submucosal dissection (ESD) was developed in Japan to resect larger lesions, but ESD was not covered by the Japanese national health insurance until April 2012. In addition, treatment strategies vary considerably among medical facilities. To evaluate the current situation in Japan regarding endoscopic treatment of CRNs measuring ≥20 mm, we conducted a prospective multicenter study at 18 medium-volume and high-volume specialized facilities in cooperation with the Japan Society for Cancer of the Colon and Rectum (JSCCR).

METHODS

The JSCCR conducted a multicenter, observational study of all patients treated by CER and ESD of CRNs measuring ≥20 mm.

RESULTS

From October 2007 to December 2010, CERs and ESDs were performed on 1,845 CRNs (CERs 1,029; ESDs 816). Lesions diagnosed as protruded, flat, and depressed totaled 541, 1224, and 48, respectively. En bloc resection rates and mean procedure times for CER/ESD were 56.9%/94.5% (P < 0.01) and 18 ± 23 min/96 ± 69 min, respectively. The average ESD procedure time was 129 ± 83 min in the ≥40-mm group. As lesion size increased, the CER en bloc resection rate decreased significantly (trend P < 0.01), but the ESD en bloc resection rate remained over 93%. Perforation and delayed bleeding rates of CER/ESD were 0.8%/1.6% (P < 0.05) and 2%/2.2% (P = 0.3), respectively.

CONCLUSIONS

The en bloc resection rate for ESD was significantly higher than for CER, although complication rates were fairly low. Despite a longer procedure time, safety of colorectal ESD has improved in various facilities in Japan. However, ESD for lesions measuring ≥40 mm must be performed by experienced endoscopists due to the longer procedure time.

Indications for and technical aspects of colorectal endoscopic submucosal dissection

Due to the widespread acceptance of gastric and esophageal endoscopic submucosal dissections (ESDs), the number of medical facilities that perform colorectal ESDs has grown and the effectiveness of colorectal ESD has been increasingly reported in recent years. The clinical indications for colorectal ESD at the National Cancer Center Hospital, Tokyo, Japan include laterally spreading tumor (LST) nongranular type lesions >20 mm and LST granular type lesions >30 mm. In addition, 0-IIc lesions >20 mm, intramucosal tumors with nonlifting signs and large sessile lesions, all of which are difficult to resect en bloc by conventional endoscopic mucosal resection (EMR), represent potential candidates for colorectal ESD. Rectal carcinoid tumors less than 1 cm in diameter can be treated simply, safely, and effectively by endoscopic submucosal resection using a ligation device and are therefore not indications for ESD. The en bloc resection rate was 90%, and the curative resection rate was 87% for 806 ESDs. The median procedure time was 60 minutes, and the mean size for resected specimens was 40 mm (range, 15 to 150 mm). Perforations occurred in 23 (2.8%) cases, and postoperative bleeding occurred in 15 (1.9%) cases, but only two perforation cases required emergency surgery (0.25%). ESD was an effective procedure for treating colorectal tumors that are difficult to resect en bloc by conventional EMR. ESD resulted in a higher en bloc resection rate as well as decreased invasiveness in comparison to surgery. Based on the excellent clinical results of colorectal ESDs in Japan, the Japanese healthcare insurance system has approved colorectal ESD for coverage.

Safety and efficacy of colorectal endoscopic submucosal dissection in elders: clinical and follow-up outcomes

PURPOSE

Endoscopic submucosal dissection (ESD) has recently been applied to treatment of colorectal neoplasia; however, its safety and efficacy in terms of follow-up outcomes in elders have not been thoroughly examined. The aim of this study is to describe the clinical outcomes of colorectal ESD in elderly patients.

METHODS

Two groups of patients, elderly (≥ 75 years of age) and non-elderly (< 75 years of age), who underwent colorectal ESD at the National Cancer Center Hospital from February 1998 to December 2010 were retrospectively compared on the following measures: tumor size, procedure time, complication rates, en bloc resection rates, and curative resection rates. We also investigated the follow-up outcomes in non-curative resection cases.

RESULTS

Of 614 consecutive patients treated by colorectal ESD, 125 (20.4 %) comprised the elderly group, and 489 patients (79.6 %) comprised the non-elderly group. No significant differences were observed between the two groups in terms of tumor size, procedure time, complication rates, en bloc resection rates, and curative resection rates. Of the patients who underwent non-curative resection, 7/19 (36.8 %) and 47/63 (74.6 %) in the elderly and non-elderly group, respectively, underwent additional treatment. Among the elderly patients who were followed up without additional treatment, no case of local recurrence, residual lesions, or distant metastases was observed during the observation period.

CONCLUSION

Treatment outcomes of colorectal ESD were equivalent in both groups. However, many of the non-curative cases in the elderly patients were followed up without additional treatment. Future studies should focus on the outcome in such patients to confirm the feasibility of colorectal ESD in elderly patients.

Colorectal endoscopic submucosal dissection in Japan and Western countries

Various studies by Japanese endoscopists have demonstrated that colorectal endoscopic submucosal dissection (ESD) can overcome technical limitations of the endoscopic mucosal resection (EMR) technique such as piecemeal resection for flat lesions larger than 20 mm, resection of lesions involving the dentate line or the ileocecal valve and lesions with the non-lifting sign, and achieve higher en bloc resection rate. However, it is infrequently performed in Western countries in comparison with Japan, despite the advantages explained above. There are some differences between Japan and Western countries in environments and clinical settings for performing ESD in the colorectum. Endoscopists who perform colorectal ESD around the world are considering that refinements in ESD techniques, devices and training will be necessary to further reduce a higher risk of complications and longer procedure times before adoption of ESD can be recommended on a widespread international scale.

Current status of colorectal endoscopic submucosal dissection in Japan and other Asian countries: progressing towards technical standardization

AIM

The primary purpose of this questionnaire survey study was to determine the current status of colorectal endoscopic submucosal dissection (ESD) in specialized Japanese referral centers before and after introduction of a government-approved advanced medical treatment system; and, secondly, to determine the current status of colorectal ESD in other Asian specialized referral centers.

METHODS

A total of 1321 colorectal ESDs were performed in 11 institutions including two Asian centers outside Japan.

RESULTS

Overall en-bloc resection, curative resection, R0 resection, perforation, delayed bleeding and emergency surgery rates were 95.4%, 89.1%, 87.2%, 2.9%, 2.5% and 0.2%, respectively. Similar clinical results were reported in the two Asian centers.

CONCLUSION

There were no significant differences with regards to clinical results between the two periods although the perforation rate decreased from 3.3% to 2.4%. In addition, colorectal ESD has become increasingly standardized technically at specialized referral centers not only in Japan, but several other Asian referral institutions as well.

Impact of endoscopic submucosal dissection for the therapeutic strategy of large colorectal tumors

BACKGROUND AND AIMS

The change of therapeutic strategy for large colorectal tumors after the introduction of endoscopic submucosal dissection (ESD) has not yet been clarified. The aim of this study was to estimate the impact of ESD as an initial treatment strategy.

METHODS

A questionnaire was administered to nine expert panelists in colorectal ESD. The questionnaire used retrospective data from consecutive case series. Forty-seven cases of early colorectal tumors (≥ 20 mm) were included. Endoscopic growth types were 25 laterally-spreading tumors (LST) of granular type (G), 15 LST of non-granular types (NG), and seven protruded types. Pathological diagnoses included 15 adenomas (Ad), 18 intramucosal cancers (M), three submucosally-shallow invasive cancers (< 1000 µm) (SMs), and 11 submucosally-deep invasive cancers (≥ 1000 µm) (SMd). The expert panelists completed questionnaires about recommended initial treatment under suppositions of before and after the introduction of ESD. Over-surgery was defined as surgery for Ad, M, and SMs. Non-curative endoscopic resection (ER) was defined as ER for SMd.

RESULTS

After the introduction of ESD, the reduction in the over-surgery rate was estimated at 10.8% for Ad, M, and SMs, and the increase in the non-curative ER rate was estimated at 27.2% for SMd. By endoscopic growth type, the reduction of over-surgery rates for LST-NG, LST-G, and protruded type was 15.5%, 10.5%, and 2.2%, respectively.

CONCLUSIONS

The endoscopists changed their therapeutic strategy for large colorectal tumors to reduce over-surgery, especially in LST-NG, demonstrating the impact of ESD.

Comparing endoscopic submucosal dissection with transanal resection for non-invasive rectal tumor: a retrospective study

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is an alternative to transanal resection (TAR) in treating rectal adenomas, intramucosal cancers, and superficial submucosal cancers. The purpose of this study is to compare the clinical efficacy between ESD and TAR for non-invasive rectal tumors.

METHODS

Between January 1998 and December 2006, 85 patients with preoperative diagnosis of non-invasive rectal tumors were treated by ESD or TAR. En-bloc resection, local recurrence, complication, procedure time, and hospital stay were evaluated retrospectively using a prospectively-completed database.

RESULTS

Mean resection sizes were 40 mm and 39 mm in diameter for the ESD and TAR groups, respectively. En-bloc resections with a negative resection margin were achieved in 67% (35/52) of the ESD group, which was significantly higher than the 42% (14/33) in the TAR group. Sixty-three lesions were diagnosed as curative resection, histopathologically. There was no local recurrence in the ESD group, but five local recurrences developed in the TAR group. Two rectal perforations, one minor delayed bleeding, and one subcutaneous emphysema in the ESD group were successfully managed conservatively. There were one minor delayed bleeding and two anesthesia-related complications in the TAR group. The ESD group had a shorter hospital stay than the TAR group (4.9 days vs 7 days), but a longer procedure time (131 min vs 63 min).

CONCLUSION

ESD was more effective than TAR in treating non-invasive rectal tumors, with a lower recurrence rate and shorter hospital stay.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

A prospective, multicenter study of 1111 colorectal endoscopic submucosal dissections (with video)

BACKGROUND

Endoscopic submucosal dissection (ESD) is accepted as a minimally invasive treatment for early gastric cancer, although it is not widely used in the colorectum because of technical difficulty.

OBJECTIVE

To examine the current status of colorectal ESDs at specialized endoscopic treatment centers.

DESIGN AND SETTING

Multicenter cohort study using a prospectively completed database at 10 specialized institutions.

PATIENTS AND INTERVENTIONS

From June 1998 to February 2008, 1111 colorectal tumors in 1090 patients were treated by ESD.

MAIN OUTCOME MEASUREMENTS

Tumor size, macroscopic type, histology, procedure time, en bloc and curative resection rates and complications.

RESULTS

Included in the 1111 tumors were 356 tubular adenomas, 519 intramucosal cancers, 112 superficial submucosal (SM) cancers, 101 SM deep cancers, 18 carcinoid tumors, 1 mucosa-associated lymphoid tissue lymphoma, and 4 serrated lesions. Macroscopic types included 956 laterally spreading tumors, 30 depressed, 62 protruded, 44 recurrent, and 19 SM tumors. The en bloc and curative resection rates were 88% and 89%, respectively. The mean procedure time ± standard deviation was 116 ± 88 minutes with a mean tumor size of 35 ± 18 mm. Perforations occurred in 54 cases (4.9%) with 4 cases of delayed perforation (0.4%) and 17 cases of postoperative bleeding (1.5%). Two immediate perforations with ineffective endoscopic clipping and 3 delayed perforations required emergency surgery. Tumor size of 50 mm or larger was an independent risk factor for complications, whereas a large number of ESDs performed at an institution decreased the risk of complications.

LIMITATIONS

No long-term outcome data.

CONCLUSIONS

ESD performed by experienced endoscopists is an effective alternative treatment to surgery, providing high en bloc and curative resection rates for large superficial colorectal tumors.

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

BACKGROUND AND STUDY AIM

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Outcome of endoscopic submucosal dissection for colorectal tumors accompanied by fibrosis

OBJECTIVE

Colorectal endoscopic submucosal dissection (ESD) is a difficult procedure. We aimed to retrospectively assess the relationship between the outcome of ESD for colorectal tumors and the degree of fibrosis.

PATIENTS AND METHODS

We examined 203 consecutive patients with colorectal tumors larger than 20 mm in diameter who had undergone ESD at our hospital from November 2002 to June 2009. During ESD, the degree of submucosal fibrosis was classified into three types (F0-2). The relationship between the degree of fibrosis and the lesion characteristics and those between the outcome of ESD and the degree of fibrosis were analyzed.

RESULTS

In the cases of granular laterally spreading tumors, the incidence of F2 fibrosis in nodular mixed-type tumors was significantly higher than that in homogenous-type tumors. An increase in the experience of the operators caused significant improvements in the rates of complete en bloc resection (p = 0.022) and perforation (p = 0.03) in the cases of lesions with F0-1 fibrosis. By contrast, operator experience did not cause any significant improvements in the rates of complete en bloc resection and perforation in the cases of lesions with F2 fibrosis.

CONCLUSIONS

Experienced operators could safely perform complete en bloc resection in the cases of lesions with F0-1 fibrosis. However, in the cases of lesions with F2 fibrosis, the rate of complete en bloc resection was low and the perforation rate was high even when ESD was performed by an experienced operator.

[A case of synchronous colonic laterally spreading tumors treated by sequential endoscopic submucosal dissection performed on two consecutive days]

Endoscopic submucosal dissection (ESD) is an useful therapeutic technique for large gastrointestinal epithelial tumors that it provides an en bloc resection. Although there is some controversy about the role of ESD for colorectal lesions, for large lesions in the distal rectum, ESD has the advantage of preserving anal function. However, the large amount of insufflating gas used during the procedure can cause severe abdominal pain and discomfort. Moreover, high intra-luminal pressure caused by a by large amount of gas can cause a micro-perforation. There is no consensus as to whether ESD is the optimal treatment for synchronous large colorectal laterally spreading tumors (LSTs) that cannot be removed en-bloc by conventional endoscopic mucosal resection. Here, a case with two neighboring synchronous large LSTs, one located in the rectum and the other in the distal sigmoid colon, were sequentially removed by separate ESD procedures performed on two consecutive days in a patient who could not tolerate a long procedure.

Endoscopic submucosal dissection of non-polypoid colorectal neoplasms

Traditionally, endoscopic mucosal resection and surgery were the only available treatments for large colorectal tumors, even for those detected at an early stage. The endoscopic submucosal dissection (ESD) technique, which enables en-bloc resection of large tumors, is accepted as a standard minimally invasive treatment for early gastric cancer in Japan. This article explains in detail how ESD is performed and compares it with endoscopic mucosal resection.

Can endoscopic ultrasound predict early rectal cancers that can be resected endoscopically? A meta-analysis and systematic review

BACKGROUND

Rectal cancers that are confined to the mucosa (T0) can be resected endoscopically. This can help the patient avoid transabdominal surgery. The published data on accuracy of endoscopic ultrasound (EUS) to predict T0 stage of rectal cancers has been varied.

AIM

To evaluate the accuracy of EUS in T0 staging of rectal cancers. METHOD (STUDY SELECTION CRITERIA): Only EUS studies confirmed by surgery were selected. T0 was defined as tumor confined to the mucosa. DATA COLLECTION AND EXTRACTION: Articles were searched in Medline, PubMed, and CENTRAL.

STATISTICAL METHOD

Pooling was conducted by both the fixed-effects model and random-effects model.

RESULTS

An initial search identified 3,360 reference articles. Of these, 339 relevant articles were selected and reviewed. Eleven studies (N = 1,791) which met the inclusion criteria were included in this analysis. Pooled sensitivity of EUS in diagnosing T0 was 97.3% (95% CI: 93.7-99.1). EUS had a pooled specificity of 96.3% (95% CI: 95.3-97.2). The positive likelihood ratio of EUS was 21.9 (95% CI: 16.3-29.7) and negative likelihood ratio was 0.08 (95% CI: 0.04-0.15). All the pooled estimates, calculated by fixed and random effect models, were similar. The P-value for Chi-squared heterogeneity for all the pooled accuracy estimates was >0.10.

CONCLUSIONS

EUS has excellent sensitivity and specificity, this helps accurately diagnose T0 stage of rectal cancers. Over the past two decades, the sensitivity and specificity of EUS to diagnose T0 stage of rectal cancers has remained high. This can help physicians offer endoscopic treatment to these patients, therefore EUS should be strongly considered for staging of early rectal cancers.

Balloon overtube-guided colorectal endoscopic submucosal dissection

AIM: To evaluate the usefulness of a balloon overtube to assist colorectal endoscopic submucosal dissection (ESD) using a gastroscope.

METHODS: The results of 45 consecutive patients who underwent colorectal ESD were analyzed in a single tertiary endoscopy center. In preoperative evaluation of access to the lesion, difficulties were experienced in the positioning and stabilization of a gastroscope in 15 patients who were thus assigned to the balloon-guided ESD group. A balloon overtube was placed with a gastroscope to provide an endoscopic channel to the lesion in cases with preoperatively identified difficulties related to accessibility. Colorectal ESD was performed following standard procedures. A submucosal fluid bleb was created with hyaluronic acid solution. A circumferential mucosal incision was made to marginate the lesion. The isolated lesion was finally excised from the deeper layers with repetitive electrosurgical dissections with needle knives. The success of colorectal ESD, procedural feasibility, and procedure-related complications were the main outcomes and measurements.

RESULTS: The overall en bloc excision rate of colorectal ESD during this study at our institution was 95.6%. En bloc excision of the lesion was successfully achieved in 13 of the 15 patients (86.7%) in the balloon overtube-guided colorectal ESD group, which was comparable to the results of the standard ESD group with better accessibility to the lesion (30/30, 100%, not statistically significant).

CONCLUSION: Use of a balloon overtube can improve access to the lesion and facilitate scope manipulation for colorectal ESD.

Endoscopic submucosal dissection (ESD) for colorectal tumors

BACKGROUND

Endoscopic submucosal dissection (ESD) is accepted as a minimally invasive treatment for early gastric cancer, however, it is not widely used in the colorectum because of its technical difficulty.

OBJECTIVE

To determine the feasibility of using ESD for treating large superficial colorectal tumors.

PATIENTS

A total of 400 consecutive patients were treated by ESD for 405 lesions at National Cancer Center Hospital, Tokyo, Japan.

INTERVENTIONS

Endoscopic submucosal dissection procedures were performed using a bipolar needle knife (B-knife) or an insulation-tip knife (IT knife).

RESULTS

The en-bloc resection rate was 87% and the curative resection rate was 86% among the 405 ESDs: 101 involved tubular adenomas, 255 intramucosal cancers and minute submucosal cancers, 46 submucosal deep cancers and 3 others (MALT and carcinoid tumors). The median operation time was 90 minutes and the mean size of resected specimens was 40 mm (range: 15 mm-150 mm). Perforations occurred in 14 (3.5%) cases and postoperative bleeding in four (1%) cases, but only one perforation case needed emergency surgery because endoscopic clipping was ineffective.

LIMITATIONS

Conducted at single center.

CONCLUSIONS

Endoscopic submucosal dissection is a feasible technique for treating large superficial colorectal tumors because it provides a higher en-bloc resection rate and is less invasive than surgical resection.

Clinical outcome of endoscopic submucosal dissection versus endoscopic mucosal resection of large colorectal tumors as determined by curative resection

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) has recently been applied to the treatment of superficial colorectal cancer. Clinical outcomes compared with conventional endoscopic mucosal resection (EMR) have not been determined so our aim was to compare the effectiveness of ESD with conventional EMR for colorectal tumors >or=20 mm.

METHODS

This was a retrospective case-controlled study performed at the National Cancer Center Hospital in Tokyo, Japan involving 373 colorectal tumors >or=20 mm determined histologically to be curative resections. Data acquisition was from a prospectively completed database. We evaluated histology, tumor size, procedure time, en bloc resection rate, recurrence rate, and associated complications for both the ESD and EMR groups.

RESULTS

A total of 145 colorectal tumors were treated by ESD and another 228 were treated by EMR. ESD was associated with a longer procedure time (108 +/- 71 min/29 +/- 25 min; p < 0.0001), higher en bloc resection rate (84%/33%; p < 0.0001) and larger resected specimens (37 +/- 14 mm/28 +/- 8 mm; p = 0.0006), but involved a similar percentage of cancers (69%/66%; p = NS). There were three (2%) recurrences in the ESD group and 33 (14%) in the EMR group requiring additional EMR (p < 0.0001). The perforation rate was 6.2% (9) in the ESD group and 1.3% (3) in the EMR group (p = NS) with delayed bleeding occurring in 1.4% (2) and 3.1% (7) of the procedures (p = NS), respectively, as all complications were effectively treated endoscopically.

CONCLUSIONS

Despite its longer procedure time and higher perforation rate, ESD resulted in higher en bloc resection and curative rates compared with EMR and all ESD perforations were successfully managed by conservative endoscopic treatment.

Successful complete cure en-bloc resection of large nonpedunculated colonic polyps by endoscopic submucosal dissection: a meta-analysis and systematic review

BACKGROUND

Endoscopic submucosal dissection (ESD) has emerged as one of the techniques to successfully resect large colonic polyps en bloc. Complete resection prevents the patient from going through transabdominal colonic resection. We sought to evaluate the proportion of successful en-bloc and complete cure en-bloc resection of large colonic polyps by ESD.

METHODS

Studies that use ESD technique to resect large colonic polyps were selected. Successful en-bloc resection was defined as resection of the polyp in one piece. Successful complete cure en-bloc resection was defined as one piece with histologic disease-free-margin polyp resection. Articles were searched in Medline, PubMed, and Cochrane control trial registry. Pooled proportions were calculated by both fixed and random-effects model.

RESULTS

The initial search identified 2,120 reference articles; 389 relevant articles were selected and reviewed. Data were extracted from 14 studies (n = 1,314) that met the inclusion criteria. The mean +/- standard error size of the polyps was 30.65 +/- 2.88 mm. Pooled proportion of en-bloc resection by the random-effects model was 84.91% (95% confidence interval, 77.82-90.82) and complete cure en-bloc resection was 75.39% (95% confidence interval, 66.69-82.21). The fixed-effects model was not used because of the heterogeneity of studies.

CONCLUSIONS

ESD should be considered the best minimally invasive endoscopic technique in the treatment of large (>2 cm) sessile and flat polyps because it allows full pathological evaluation and cure in most patients. ESD offers an important alternative to surgery in the therapy of large sessile and flat polyps.

Supplementation of endoscopic submucosal dissection with sentinel node biopsy performed by natural orifice transluminal endoscopic surgery (NOTES) (with video)

BACKGROUND

Endoscopic submucosal dissection (ESD) is proving to be effective for the resection of selected early gastric and colon cancers. Its application and appropriateness could be extended if a means of determining lymphatic dissemination without recourse to a conventional operation could be provided.

OBJECTIVE

To demonstrate the feasibility of companion sentinel node biopsy (SNB) by natural orifice transluminal endoscopic surgery (NOTES) concurrent with intraluminal ESD in both the sigmoid colon and stomach.

DESIGN

Acute porcine model.

INTERVENTION

Arbitrarily selected mucosal foci were targeted for combined NOTES-SNB and ESD in the sigmoid and stomach of 2 separate anesthetized animals. NOTES peritoneal access was obtained either transgastrically or transvaginally. A second intraluminal endoscope was passed either orally or rectally, as appropriate, to perform submucosal injection for lymphatic mapping under direct vision of the NOTES endoscope. This endoscope then identified the first-order draining (sentinel) nodes and allowed their excisional biopsy. The sigmoid was retracted by magnetic assistance as required, while torque of an intraluminal gastroscope manipulated the stomach. After retrieval of the nodes, 1-cm and 1.5-cm specimens were resected from the sigmoid and stomach, respectively, by conventional ESD. At procedure end, necropsy was performed.

RESULTS

All sentinel nodes were identified, underwent biopsy, and were retrieved intact. ESD was subsequently readily performed without complication. SNB completeness and ESD quality were confirmed postprocedure.

LIMITATIONS

Experimental model with limited sample size.

CONCLUSIONS

Although not yet appropriate for human use, this proposal merits serious consideration as a potential means of augmenting the effectiveness and appropriateness of ESD techniques for GI neoplasia.

Endoscopic necrosectomy of organized pancreatic necrosis: a currently practiced NOTES procedure

BACKGROUND

Endoscopic necrosectomy is now an established minimally invasive method for treatment of organized pancreatic necrosis.

METHODS

Review of methods and results of endoscopic treatment of pancreatic necrosis.

RESULTS

Reports by multiple groups have demonstrated favorable results of endoscopic necrosectomy. The mortality of critically ill patients undergoing endoscopic treatment in several series is approximately 10%. Some patients will eventually also require surgery for situations such as complete pancreatic duct disruption, but even in these cases endoscopic necrosectomy is useful because pancreatic surgery can often be delayed until the patient is stable.

CONCLUSIONS

Endoscopic necrosectomy will likely assume an increasing role in the treatment of pancreatic necrosis. This should result in reduced morbidity and mortality in these critically ill patients.

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.