Thin endoscope-assisted endoscopic submucosal dissection for large colorectal tumors (with videos)

BACKGROUND: Endoscopic submucosal dissection (ESD) enables direct submucosal dissection so even large early stage GI tumors can be resected en bloc. Colorectal ESD is technically more difficult, however, and there is an increased risk of complications such as perforation and bleeding compared with gastric ESD. As a result, further refinements are required in this procedure. OBJECTIVE: Our purpose was to evaluate thin endoscope-assisted (TEA) ESD, a new traction system for improving submucosal cutting line visualization. DESIGN: Case series. SETTING: Okayama University Hospital. MAIN OUTCOME MEASUREMENTS: Efficacy and safety of the TEA-ESD procedure. RESULTS: Three cases of large, flat, elevated colorectal tumors (laterally spreading tumors) in the rectum and rectosigmoid colon were safely and successfully removed en bloc without complications. Total procedure times were 3 hours, 40 minutes, and 30 minutes with resected specimens measuring 70 x 68 mm, 38 x 35 mm, and 30 x 20 mm, respectively. LIMITATIONS: TEA-ESD was performed in only the rectum and rectosigmoid colon. CONCLUSIONS: This limited case series demonstrated that large laterally spreading tumors in the rectum and rectosigmoid colon could be safely resected en bloc with TEA-ESD.     

Endoscopic mucosal resection with a ligation device or endoscopic submucosal dissection for rectal carcinoid tumors: An analysis of 24 consecutive cases

Aims: Endoscopic submucosal dissection (ESD) has several advantages over conventional endoscopic mucosal resection, including a higher en bloc resection rate and more accurate pathological estimation. However, ESD is a complex procedure that requires advanced endoscopic skills. The aim of our study is to evaluate the efficacy of endoscopic mucosal resection with a ligation device (EMR‐L) compared to ESD for rectal carcinoid tumors. Methods: Between September 2003 and April 2011, 24 rectal carcinoid tumors in 24 patients treated by ESD or EMR‐L were retrospectively analyzed. The indications for endoscopic treatment were node‐negative rectal carcinoid tumors. We compared the therapeutic outcomes of the ESD group (n = 13) and the EMR‐L group (n = 11). Results: Both groups had similar mean tumor sizes (ESD: 5.5 ± 2.1 mm; EMR‐L: 4.4 ± 2.2 mm). The rates of en bloc and complete resection were, respectively, 100% and 92.3% for ESD, and 100% and 100% for EMR‐L. Perforations did not occur in either group. Postoperative bleeding occurred in one EMR‐L case, and it was endoscopically managed. However, there were no differences in therapeutic outcomes between the two groups. The mean procedure time was longer in the ESD group (28.8 ± 16.2 min) than in the EMR‐L group (17.4 ± 4.4 min), without a significant difference. The mean hospitalization period was significantly shorter in the EMR‐L group (1.8 ± 3.1 day) than in the ESD group (6.2 ± 2.1 day), and eight EMR‐L cases were treated in an outpatient setting. Conclusions: EMR‐L is a simple and effective procedure that compares favorably to ESD for small rectal carcinoid tumors.     

Advantages of endoscopic submucosal dissection versus endoscopic oblique aspiration mucosectomy for superficial esophageal tumors

Background and Aim: In the treatment of superficial esophageal tumors (SET), en bloc histologically‐complete resection reduces the risk of local recurrence. Endoscopic oblique aspiration mucosectomy (EOAM) and endoscopic submucosal dissection (ESD) have been applied to resect SET. The aim of this study was to retrospectively determine whether ESD is more advantageous than EOAM for SET. Methods: In the present study, there was a total of 122 patients in whom 162 SET were resected endoscopically at Hiroshima University Hospital. EOAM (83 lesions/63 patients) or ESD (79 lesions/59 patients) was performed. En bloc histologically‐complete resection rates, operation time, complications, and the local recurrence rate were studied. Results: In SET > 20 mm, the en bloc histologically‐complete resection rate was significantly higher with ESD than with EOAM (94% vs 42%, P < 0.001). In SET of 16–20 mm, the rate tended to be higher with ESD than with EOAM (100% vs 81%, P = 0.08). In SET < 15 mm, the rates did not differ significantly between groups. The average operation time was significantly longer for ESD than for EOAM, regardless of tumor size (49.7 ± 33.0 min vs 19.1 ± 6.1 min, P < 0.001). Complication rates did not differ significantly between groups. The local recurrence rate was significantly lower with ESD than with EOAM (0%, mean observation period: 18.9 months vs 9%, mean observation period: 30.7 months, P = 0.03). Conclusion: Although increased operation time with ESD remains problematic, SET >15 mm should be treated with ESD to reduce local recurrence. In lesions ≤15 mm, EOAM might be preferable, especially in high‐risk patients.     

Matched case-control study comparing endoscopic submucosal dissection and endoscopic mucosal resection for colorectal tumors

Background and Aim: For large colorectal tumors, the en bloc resection rate achieved by endoscopic mucosal resection (EMR) is insufficient, and this leads to a high rate of local recurrence. As endoscopic submucosal dissection (ESD) has been reported to achieve a higher rate of en bloc resection and a lower rate of local recurrence in the short‐term, it is expected to overcome the limitations of EMR. We conducted a matched case‐control study between ESD and EMR to clarify the effectiveness of ESD for colorectal tumors. Methods: Between April 2005 and February 2009, a total of 28 colorectal tumors in 28 patients were resected by ESD and were followed up by colonoscopy at least once. As a control group, 56 EMR cases from our prospectively completed database were matched. En bloc resection, complication and recurrence rates were compared between the two groups. Results: The mean sizes of the lesions were 27.1 mm in the ESD group and 25.0 mm in the EMR group. The en bloc resection rate was significantly higher in the ESD group (92.9% vs 37.5% with ESD vs EMR), and the rate of perforation was also significantly higher (10.7% vs 0%). All cases of perforation were managed conservatively. No recurrence was observed in the ESD group, whereas local recurrences were detected in 12 EMR cases (21.4%). Eleven of the 12 recurrences (91.7%) were managed endoscopically, and one required surgical resection. Conclusions: Endoscopic submucosal dissection is a promising technique for the treatment of colorectal tumors, giving an excellent outcome in comparison with EMR.     

Beyond the snare: technically accessible large en bloc colonic resection in the West: an animal study

Background: Endoscopic submucosal dissection (ESD) and circumferential submucosal incision endoscopic mucosal resection (CSI‐EMR) are techniques for en bloc excision of large sessile colonic lesions. Our aims were to compare the efficacy, safety and learning curve of colonic hybrid knife (HK) ESD versus CSI‐EMR for en bloc excision of 50 mm diameter hemi‐circumferential artificial lesions in a porcine model. Patients and Methods: Two separate 50 mm diameter areas of normal recto‐sigmoid mucosa were marked out in each of ten pigs. One was excised with HK‐ESD using succinylated gelatin (SG) submucosal injection. The other was isolated with CSI with the Insulated Tip Knife 2 followed by SG submucosal injection then EMR with a large snare. Euthanasia and colectomy was performed at 72 h followed by blinded histopathology assessment. Results: En bloc excision rates were: HK‐ESD 100% versus CSI‐EMR 20% (P = 0.008). The mean number of resections per lesion was HK‐ESD 1 versus CSI‐EMR 3 (P = 0.001). The mean dimensions of the largest specimen per technique were HK‐ESD 63 × 54 mm versus CSI‐EMR 49 × 41 mm (P = 0.005). Procedure duration mean was HK‐ESD 54 min versus CSI‐EMR 22 min (P < 0.001). When procedure duration was adjusted for the size of the resected en bloc specimen, a statistically significant and accelerated learning effect was noted for HK‐ESD (r = ?0.83, P = 0.003). There were no perforations and no significant bleeding. Conclusions: HK‐ESD with SG submucosal injection is superior to CSI‐EMR for en bloc excision of 50 mm diameter lesions in a porcine model. The technique is rapidly learnt. This novel approach may lower the barrier to colonic ESD for Western endoscopists.     

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.     

新型牵引装置在结直肠侧向发育型肿瘤内镜黏膜下剥离术中的有效性研究

目的 研究新型牵引装置在结直肠侧向发育型肿瘤（laterally spreading tumor,LST）内镜黏膜下剥离术（endoscopic submucosal dissection,ESD）中的有效性。 方法 收集2018年8月—2020年4月首都医科大学附属北京朝阳医院内镜中心经ESD治疗的结直肠LST患者资料,根据手术过程中是否使用牵引,分为传统ESD组（不使用牵引）及牵引辅助ESD组（利用3个夹子和1个橡皮圈组成弹性三角形牵引装置进行牵引）。分析两组总切除时间、黏膜下剥离时间、黏膜下剥离速率以及安全性等相关指标。 结果 共纳入54例结直肠LST患者,其中29例为传统ESD组,25例为牵引辅助ESD组。两组年龄、性别构成、病变位置比较差异均无统计学意义（P>0.05）。牵引辅助ESD组的病变面积为13.30（7.55,15.91）cm2,较传统ESD组的6.90（5.50,13.50）cm2大,差异有统计学意义（U=503.50,P=0.014）。传统ESD组与牵引辅助ESD组总切除时间[48.00（35.50,58.00）min比34.00（29.00,35.00）min,U=109.00,P<0.001]和黏膜下剥离时间[（39.52±12.37） min比（25.68±7.37）min,t=4.89,P<0.001]比较差异有统计学意义。牵引辅助ESD组黏膜下剥离速率快于传统ESD组[0.17（0.13,0.30）cm2/min比0.52（0.30,0.62）cm2/min,U=604.00,P<0.001]。传统ESD组有2例（6.9%）穿孔,牵引辅助ESD无穿孔发生,但穿孔发生率比较差异无统计学意义（P=0.493）。 结论 利用夹子及橡皮圈进行牵引辅助的ESD相对于传统ESD治疗结直肠LST更加安全、有效。     

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)

BACKGROUND: Endoscopic submucosal dissection (ESD) was recently developed in Japan for en bloc removal of laterally spreading tumors (LSTs). Although initially used for gastric tumors, ESD has now been applied to lesions elsewhere in the gut. Recent reports from Japan included removal of colorectal lesions up to 10 cm. OBJECTIVE: To show the feasibility of ESD to remove en bloc, very large LSTs of the rectum, even when there is involvement to the dentate line. DESIGN: Case report. SETTING: The procedure was performed at an American GI unit. The patient was admitted to the hospital after the procedure for observation. PATIENTS: A 53-year-old patient, with a 14-cm tubulovillous adenoma of the rectum, which, at its maximal extent, involved two thirds of the circumference of the rectum. The tumor extended distally to the dentate line. INTERVENTIONS: En bloc submucosal dissection with a conventional needle-knife to remove the neoplasm. MAIN OUTCOME MEASUREMENTS: Completeness of en bloc removal of the tumor and subsequent follow-up endoscopy that showed no residual neoplasm. RESULTS: The tumor was able to be removed en bloc by ESD. The distal margin included squamous mucosa. At a 2.5-week endoscopic follow-up, a 3-mm focus of residual polyp was seen and removed. At the time of the last follow-up, there was complete healing of the wound and no residual neoplasm. LIMITATIONS: Single case. CONCLUSIONS: This case demonstrated the feasibility of using ESD to remove large laterally spreading rectal tumors, including when there was involvement to the dentate line (and the dissection line must include squamous mucosa of the anal canal). ESD is a promising alternative to conventional surgical techniques; however, additional published experience is needed.     

内镜黏膜下剥离术治疗直肠侧向发育型肿瘤的临床价值(附视频)

目的研究直肠侧向发育型肿瘤(LST)的临床病理学特征,并评价内镜黏膜下剥离术(ESD)治疗直肠LST的疗效及安全性。 方法收集2008年4月至2012年1月期间,复旦大学附属中山医院内镜中心行ESD治疗的120例直肠LST患者的临床资料。首先按内镜下表面形态将120例LST进行分型,统计各型LST的部位、大小、形态特征,然后对LST的临床病理特点以及ESD治疗的切除率、手术时间、并发症和复发情况进行分析。 结果120例直肠LST病变中84例为颗粒型(84/120,70%),36例为非颗粒型(36/120,30%),平均病变大小为35 mm。其中绒毛状管状腺瘤占38.3%,高级别上皮内瘤变28.3%,黏膜下癌7.5%。平均手术时间为：51.8±28.16(17～110)min,整块切除率为98.3%,完整切除率为95.0%,完整治愈切除率为90.8%。ESD术后出血发生率为4.2%,穿孔发生率为3.3%。平均随访时间为32.6个月,复发率为0.8%。 结论直肠LST病变大于2 cm,存在较高的恶变潜能。ESD治疗LST病变整块切除率高,复发率较低,是直肠LST病变安全且有效的治疗方法。     

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.     

Usefulness of sodium hyaluronate solution in colorectal endoscopic mucosal resection

Background: In endoscopic mucosal resection (EMR), it is essential to inject submucosal fluid to prevent complications and ensure safe and complete en bloc resection of tumors. Sodium hyaluronate (SH) solution, which is effective in forming and maintaining a mucosal lift and is innocuous to mucosal tissue, is considered a useful injection solution for endoscopic submucosal dissection, a procedure associated with a high risk of perforation. This study was undertaken to assess the usefulness of this solution in EMR. Methods: Ninety‐four patients with colorectal tumors of ≤20 mm in diameter were enrolled for this study and randomized to a SH solution group (0.2% two‐fold diluted MucoUp) or to a normal saline group (control). Ease of EMR was primarily assessed based on ease of submucosal injection, ease of snaring and injection time. Results: SH solution was superior to normal saline for ease of submucosal injection (57 ± 0.7 vs 50 ± 0.7; P < 0.05), and it showed better results for ease of snaring with less variability (63 ± 0.8 vs 51 ± 1.0; P < 0.05). The mean injection time was similar between the two groups (3.0 ± 9.0 s and 3.0 ± 2.7 s, respectively). Post‐procedural hemorrhage occurred in 7% patients (3/46) injected with SH solution and in 6% of patients (3/48) in the control group; there was no significant difference between the groups. Conclusions: Use of two‐fold diluted MucoUp facilitated colorectal EMR.     

Clinical outcomes of endoscopic submucosal dissection and endoscopic mucosal resection for laterally spreading tumors larger than 20 mm

Background and Aims: Colorectal laterally spreading tumors (LST) > 20 mm are usually treated by endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR). Endoscopic piecemeal mucosal resection (EPMR) is sometimes required. The aim of our study was to compare the outcomes of ESD and EMR, including EPMR, for such LST. Methods: A total of 269 consecutive patients with a colorectal LST > 20 mm were treated endoscopically at our hospital from April 2006 to December 2009. We retrospectively evaluated the complications and local recurrence rates associated with ESD, hybrid ESD (ESD with EMR), EMR, and EPMR. Results: ESD and EMR were performed successfully for 89 and 178 LST, respectively: 61 by ESD; 28 by hybrid ESD; 70 by EMR; and 108 by EPMR. Between‐group differences in perforation rates were not significant. Local recurrence rates in cases with curative resection were as follows: 0% (0/56) in ESD; 0% (0/27) in hybrid ESD; 1.4% (1/69) in EMR; and 12.1% (13/107) in EPMR; that is, significantly higher in EPMR. No metastasis was seen at follow up. The recurrence rate for EPMR yielding ≥ three pieces was significantly high (P < 0.001). All 14 local recurrent lesions were adenomas that were cured endoscopically. Conclusions: As for safety, ESD/hybrid ESD is equivalent to EMR/EPMR. ESD/hybrid ESD is a feasible technique for en bloc resection and showed no local recurrence. Although local recurrences associated with EMR/EPMR were seen, which were conducted based on our indication criteria, all local recurrences could obtain complete cure by additional endoscopic treatment.     

ENDOSCOPIC SUBMUCOSAL DISSECTION FOR THE RELIABLE EN BLOC RESECTION OF COLORECTAL MUCOSAL TUMORS

Scheduled piecemeal resection has been actively conducted for granular type laterally spreading tumor (LST‐G) in Japan, as long as a definite preoperative diagnosis is made. However, en bloc resection is desirable for depressed lesions (e.g. IIc lesion) as well as non‐granular type laterally spreading tumor (LST‐NG) since they have considerable high risk for submucoasl invasion and require precise histopathological evaluation. Endoscopic submucosal dissection (ESD) has been developed for the en bloc resection of mucosal tumors of gastrointestinal tract and widely applied especially in gastric lesions. Although the large intestine involves structural and technical difficulties, we conducted en bloc resection by ESD while exercising sorts of ingenuity for preparation; endoscopes, instruments, local injections, and others. ESD is a reliable technique that allows en bloc resection of gastrointestinal mucosal lesions, and even has a splendid possibility for the treatment of early stage colorectal cancer.     

结直肠侧向发育型肿瘤内镜诊断与治疗

目的探讨结直肠侧向发育型肿瘤(LST)内镜诊断方法,经内镜黏膜切除术(EMR)、分片切除术(EPMR)、内镜黏膜下剥离术(ESD)方法治疗LST的疗效、安全性。方法 LST经色素染色放大内镜或NBI-ME观察病变形态、腺管开口分型(pit)及表面微血管分型(MP),分别进行EMR、EPMR、ESD或外科手术治疗,并分析LST的病理特点。结果在399例病人检出有LST,共407个病变。LST大小在10～80mm。LST部位在直肠128个(31.4%),乙状结肠97个(23.8%),降结肠54个(13.3%),横结肠67个(16.5%),升结肠21个(5.2%),盲肠36个(8.8%),回肠末段4例(1.0%)。LST形态呈颗粒均一型145个,结节混合型161个,扁平隆起型63个,假凹陷型38个。LST腺管开口分型以ⅢL和Ⅳ为多。405个LST经肠镜微创电切治疗,228个行EMR切除,165个行EPMR切除,12个行ESD切除,均在内镜下成功电切,另2例LST行外科手术治疗。出血发生率4.0%,术中即刻出血4例,术后3天迟发出血12例,无肠穿孔发生。LST病理结果:管状腺瘤46个(11.3%),管状绒毛状腺瘤146个(35.9%),绒毛状腺瘤181个(44.5%),增生性息肉10个(2.5%),高级别上皮内瘤变19个(4.7%),黏膜内癌3个(0.7%),黏膜下癌2个(0.4%)。术后复查肠镜无复发。结论色素染色放大内镜或NBI-ME方法有利于检出LST,EMR、EPMR、ESD是内镜下治疗LST安全有效的方法。     

Is sigmoidoscopy sufficient for evaluating inflammatory status of ulcerative colitis patients?

Background and Aims: An adequate range of colonic observations for precise evaluation of inflammation in ulcerative colitis (UC) patients has not been reported. Methods: Retrospective analysis of 545 colonoscopic examinations of UC patients was carried out. Severity of mucosal inflammation was evaluated using the Mayo score of endoscopic index at each location (rectum, sigmoid colon, descending colon, and the oral side of the splenic flexure) in each patient. The colonic site with maximum inflammation was determined for each patient. Results: Of 545 patients, 319 (59%) had maximum inflammation in the rectum, 79 (14%) in the sigmoid colon, 70 (13%) in the descending colon, and 77 (14%) on the oral side of the splenic flexure. Severe inflammatory activity (Mayo 3) was observed more frequently in patients who had maximum activity in the descending colon or the more proximal portion than those who had this in the rectum or sigmoid colon (42% vs 25%, P < 0.0001). The first‐attack patients were significantly more frequently found in patients with maximum severity in the descending colon or the oral side of splenic flexure than those with maximum severity in the rectum or sigmoid colon (P = 0.016). Moreover, among 134 patients with no inflammation in the rectum and sigmoid colon, 54 (40%) had inflamed mucosa in the descending colon or the more proximal portion. Conclusions: Sigmoidoscopy is not sufficient for evaluating inflammation in UC patients. In particular, colonoscopy is necessary for first‐attack patients and patients who have a discrepancy between rectosigmoid observation and symptoms.     

Efficacy of traction‐assisted colorectal endoscopic submucosal dissection using a clip‐and‐thread technique: A prospective randomized study

Background and Aim

Colorectal endoscopic submucosal dissection (ESD) remains challenging because of technical difficulties, long procedure time, and high risk of adverse events. To facilitate colorectal ESD, we developed traction‐assisted colorectal ESD using a clip and thread (TAC‐ESD) and conducted a randomized controlled trial to evaluate its efficacy.

Methods

Patients with superficial colorectal neoplasms (SCN) ≥20 mm were enrolled and randomly assigned to the conventional‐ESD group or to the TAC‐ESD group. SCN ≤50 mm were treated by two intermediates, and SCN >50 mm were treated by two experts. Primary endpoint was procedure time. Secondary endpoints were TAC‐ESD success rate (sustained application of the clip and thread until the end of the procedure), self‐completion rate by the intermediates, and adverse events.

Results

Altogether, 42 SCN were analyzed in each ESD group (conventional and TAC). Procedure time (median [range]) for the TAC‐ESD group was significantly shorter than that for the conventional‐ESD group (40 [11–86] min vs 70 [30–180] min, respectively; P < 0.0001). Success rate of TAC‐ESD was 95% (40/42). The intermediates’ self‐completion rate was significantly higher for the TAC‐ESD group than for the conventional‐ESD group (100% [39/39] vs 90% [36/40], respectively; P = 0.04). Adverse events included one intraoperative perforation in the conventional‐ESD group and one delayed perforation in the TAC‐ESD group.

Conclusion

Traction‐assisted colorectal endoscopic submucosal dissection reduced the procedure time and increased the self‐completion rate by the intermediates (UMIN000018612).     

Safety and efficacy of colorectal endoscopic submucosal dissection by the trainee endoscopists

The colorectum is known to be the most difficult organ to perform endoscopic submucosal dissection (ESD), however, the training has not been sufficiently established. In our hospital, the essential condition to start colorectal ESD was to experience at least 30 gastric ESD and to have sufficient knowledge and techniques beforehand. Rectal ESD were initially performed under supervision of ESD experts. According to their technical acquisition, the ESD experts allocated lesions to the trainees from smaller lesions in the distal colon to larger lesions in the proximal colon. We retrospectively investigated the outcomes of 92 and 23 colorectal ESD performed by two trainee endoscopists (A/B) who gained experience on our training scheme. The rates of en bloc/complete resection for A and B were 92.4%/73.9% and 95.7%/65.2%, respectively. The rates of bleeding/perforation, which occurred only with A, were 1.1%/3.3%, respectively. Intraoperative perforation occurred in one case (4.3%) in the later period. In the later period, en bloc resection rate remained high in spite of the difficult lesions. Our training scheme enabled trainees to perform colorectal ESD effectively and safely from the initial period. Step-by-step accumulation of cases such as from the rectum to the colon may be desirable for the introduction of colorectal ESD.     

Treatment strategy for laterally spreading tumors in Japan: Before and after the introduction of endoscopic submucosal dissection

Background and Aims:  Laterally spreading tumors (LST) in the colorectum are considered good candidates for endoscopic resection (ER). Because LST-non-granular (NG) tumors show multifocal invasion into the submucosal layer, en bloc resection is necessary for adequate histopathological evaluation. Therefore, surgical resection has been recommended when a lesion is suspected to be an invasive cancer and too large to resect en bloc. The aim of the present study was to evaluate whether the introduction of colorectal ESD, which was developed for en bloc resection of early gastric cancers, could improve the en bloc resection rate of large LST-NG-type tumors and reduce the surgical resection rate.
Methods:  Between January 1999 and December 2005, a total of 166 LST-NG-type tumors measuring ≥ 20 mm in 161 patients were included in this study. The en bloc resection rate and the surgical resection rate were historically compared between two periods, before and after the introduction of ESD.
Results:  The en bloc resection rate for ER lesions was significantly higher in the latter period (35.0% [14/40] vs 76.5% [75/98]; P  < 0.001), and the rate of surgery for adenomas and intramucosal or sm minute cancers was significantly lower in the latter period (20.0% [10/50] vs 1.1% [1/89]; P  < 0.001).
Conclusions:  The introduction of colonic ESD was able to change our treatment strategy for LST, improving the en bloc resection rate and reducing the surgical resection rate.     

Warning for unprincipled colorectal endoscopic submucosal dissection: Accurate diagnosis and reasonable treatment strategy

Piecemeal endoscopic mucosal resection (EMR) is generally indicated for laterally spreading tumors (LST) >2 cm in diameter. However, the segmentation of adenomatous parts does not affect the histopathological diagnosis and completeness of cure. Thus, possible indications for piecemeal EMR are both adenomatous homogenous‐type granular‐type LST (LST‐G) and LST‐G as carcinoma in adenoma without segmentalizing the carcinomatous part. Diagnosis of the pit pattern using magnifying endoscopy is essential for determining the correct treatment and setting segmentation borders. In contrast, endoscopic submucosal dissection (ESD) is indicated for lesions requiring endoscopic en bloc excision, as it is difficult to use the snare technique for en bloc excisions such as in non‐granular‐type LST (LST‐NG), especially for the pseudodepressed type, tumors with a type V_I pit pattern, shallow invasive submucosal carcinoma, largedepressed tumors and large elevated lesions, which are often malignant (e.g. nodular mixed‐type LST‐G). Other lesions, such as intramucosal tumor accompanied by submucosal fibrosis, induced by biopsy or peristalsis of the lesion; sporadic localized tumors that occur due to chronic inflammation, including ulcerative colitis; and local residual early carcinoma after endoscopic treatment, are also indications for ESD. In clinical practice, an efficient endoscopic treatment with segregation of ESD from piecemeal EMR should be carried out after a comprehensive evaluation of the completeness of cure, safety, clinical simplicity, and cost–benefit, based on an accurate preoperative diagnosis.