Endoscopic submucosal dissection: a safe technique for colorectal tumors

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.

A Western single-center experience with endoscopic submucosal dissection for early gastrointestinal cancers

Endoscopic submucosal dissection (ESD) has gained worldwide acceptance as a treatment for early gastrointestinal cancers (EGICs). However, the management of these tumors in the Western world is still mainly surgical. Our aim was to evaluate the safety and feasibility of ESD at a European center. Based on the knowledge transferred by one of the most experienced Japanese institutions, we conducted a pilot study on 25 consecutive patients with EGICs located in the esophagus (n = 3), stomach (n = 7), duodenum (n = 1), and colon (n = 14) at our tertiary center over a 2-year-period. The main outcome measurements were complete (R0) resection, as well as en-bloc resection and the management of complications. The R0 and en-bloc resection rates were 100% and 84%, respectively. There were three cases of bleeding and five cases of perforation. With a median follow up of 18 months, two recurrences were observed. We conclude that ESD for early esophageal and gastric cancers is feasible and effective, while colonic ESD requires more expertise.

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.

Learning curve for endoscopic submucosal dissection of large colorectal tumors

BACKGROUND AND AIM

No studies have previously described the learning curve for colonic endoscopic submucosal dissection (ESD). The aim of the present study was to describe the learning curve for ESD of large colorectal tumors based on a single colonoscopist's experience.

METHODS

ESD was carried out for 120 colorectal tumors in 115 patients (68 males, median age 70 years). All procedures were carried out by a single experienced colonoscopist. The cases were grouped chronologically into three periods: (1st): cases 1-40; (2nd): cases 41-80; and (3rd): cases 81-120.

RESULTS

The learning curve was the changes in proficiency over time. Proficiency was expressed as procedure time per unit area of specimen. In the 1st, 2nd and 3rd periods, the proficiencies were 18.9, 12.6 and 12.9 (min/cm(2) ), respectively. The proficiencies in the 2nd and 3rd periods were significantly shorter than in the 1st period (t-test, P < 0.05). The en-bloc resection rates of the 1st, 2nd and 3rd periods were 92.5% (37/40), 90% (36/40) and 97.5% (39/40), respectively. The en-bloc and R0 resection rates of the 1st, 2nd and 3rd periods were 85% (34/40), 77.5% (31/40) and 92.5% (37/40), respectively. The perforation rates of the 1st, 2nd and 3rd periods were 12.5% (5/40), 5% (2/40) and 5% (2/40), respectively.

CONCLUSION

Based on our analysis of the learning curve, approximately 80 procedures must be carried out to acquire skill with ESD for large colorectal tumors. However, approximately 40 procedures were sufficient to acquire skill in avoiding perforations during the ESD procedure.

Current status in the occurrence of postoperative bleeding, perforation and residual/local recurrence during colonoscopic treatment in Japan

Bleeding, perforation, and residual/local recurrence are the main complications associated with colonoscopic treatment of colorectal tumor. However, current status regarding the average incidence of these complications in Japan is not available. We conducted a questionnaire survey, prepared by the Colorectal Endoscopic Resection Standardization Implementation Working Group, Japanese Society for Cancer of the Colon and Rectum (JSCCR), to clarify the incidence of postoperative bleeding, perforation, and residual/local recurrence associated with colonoscopic treatment. The total incidence of postoperative bleeding was 1.2% and the incidence was 0.26% with hot biopsy, 1.3% with polypectomy, 1.4% with endoscopic mucosal resection (EMR), and 1.7% with endoscopic submucosal dissection (ESD). The total incidence of perforation was 0.74% (0.01% with the hot biopsy, 0.17% with polypectomy, 0.91% with EMR, and 3.3% with ESD). The total incidence of residual/local recurrence was 0.73% (0.007% with hot biopsy, 0.34% with polypectomy, 1.4% with EMR, and 2.3% with ESD). Colonoscopic examination was used as a surveillance method for detecting residual/local recurrence in all hospitals. The surveillance period differed among the hospitals; however, most of the hospitals reported a surveillance period of 3-6 months with mainly transabdominal ultrasonography and computed tomography in combination with the colonoscopic examination.

Endoscopic submucosal dissection for treatment of rectal carcinoid tumors

BACKGROUND

Conventional EMR has been the endoscopic treatment of choice for rectal carcinoid tumors. However, histologically complete resection often cannot be achieved because the carcinoid tumors are located mainly in the submucosal layer. Endoscopic submucosal dissection (ESD), a new method for large colorectal neoplasm resection, may overcome this problem.

OBJECTIVE

To compare ESD with EMR for the endoscopic treatment of rectal carcinoid tumors.

DESIGN

A prospective case series with comparison to retrospective controls.

SETTING

Tertiary-care center.

PATIENTS

From January 2007 to January 2009 we prospectively enrolled consecutive patients with rectal carcinoid tumors less than 16 mm in diameter and with no regional lymph node enlargement shown by CT or EUS. For comparison, we retrospectively randomly selected patients who had undergone EMR for treatment of rectal carcinoid tumors between March 2000 and December 2006.

INTERVENTION

We performed ESD of rectal carcinoid tumors in prospectively enrolled patients.

MAIN OUTCOME MEASUREMENTS

Rate of en bloc resection, rate of histologically complete resection, incidence of complications, and length of procedures.

RESULTS

The ESD group contained 31 patients (18 male, 13 female; age range 34-65 years), and the EMR group contained 62 patients (42 male, 20 female; age range 22-77 years). Both groups had similar mean rectal carcinoid tumor diameters (ESD 6.8 +/- 2.4 mm, EMR 7.3 +/- 2.2 mm; P = .106). Resection time was longer in the ESD group than in the EMR group (11.4 +/- 3.7 minutes vs 4.2 +/- 3.2 minutes, P < .001). The en bloc resection rate was 100% (31 of 31) in the ESD group and 95.2% (59 of 62) in the EMR group (P = .213). The histologically complete resection rate was 90.3% (28 of 31) in the ESD group and 71.0% (44 of 62) in the EMR group (P = .035). Suspected perforation occurred in 1 ESD patient (3.2%) and in 1 EMR patient (1.6%), and both patients were successfully managed by conservative measures. Immediate bleeding occurred in 1 ESD patient (3.2%) and in 4 EMR patients (6.5%); all instances of bleeding were controlled endoscopically.

LIMITATIONS

Retrospective control study and limited experience at a single center.

CONCLUSION

Compared with EMR, ESD resulted in a higher histologically complete resection rate, had a similar complication rate, and took slightly longer to perform. Given the advantages of complete resection, these findings indicate that ESD may be considered for treatment of rectal carcinoid tumors.

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.

Local recurrence and surveillance after endoscopic resection of large colorectal tumors

Local recurrence rates after endoscopic piecemeal mucosal resection (EPMR) typically range from 10 to 23%. In our previous study, the local recurrence rate after a piecemeal resection was significantly higher than that after an en bloc resection, irrespective of tumor size or macroscopic features. To reduce local recurrence after an EPMR, it is important to carefully note the circumferences of the edge and base of the ulcer. Recently, endoscopic submucosal dissection (ESD) was developed and recognized for its effectiveness in large, complete, en bloc resections and precise pathological assessments. ESD also showed lower local recurrence rates, ranging from 0 to 3% in previous, retrospective studies. However, ESD showed a higher perforation rate and longer procedure times; thus, it is necessary to improve ESD. An appropriate surveillance interval after EPMR was still controversial, and recommendations of some guidelines ranged from 2 to 9 months. In order to determine the appropriate interval, a randomized controlled study is necessary.

New Endoscopic Techniques: Challenges and Opportunities for Surgical Pathologists

In recent years, significant clinical and technological advances have been made in endoscopic methods for diagnosis and treatment of early gastrointestinal neoplasms. However, essential information related to these novel techniques and their implications for practicing surgical pathologists have largely been missing in the general pathology literature. This article provides a general introduction to these novel therapeutic and diagnostic methods, and discusses their indications, contraindications, and potential limitations. The article aims to enable surgical pathologists to interact more efficiently with basic scientists and clinical colleagues to help implement and improve the existing clinical methods and to advance the new technologies.

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.

Active gastrointestinal bleeding: Use of hemostatic forceps beyond endoscopic submucosal dissection

To the best of our knowledge, this is the first report of the application of hemostatic forceps in active gastrointestinal (GI) bleeding that is not related to endoscopic submucosal dissection. An 86-year-old woman with chronic intake of low-dose aspirin had a Dieulafoy’s lesion of the third duodenal portion. Bleeding control with epinephrine injection was unsuccessful. A 60-year-old man presented with a bleeding ulcer in the duodenal bulb. Ten days after combined endotherapy, he had recurrent bleeding from two minimal lesions in the same location. A 66-year-old woman under combined antithrombotic treatment was referred to us for chronic GI bleeding of unexplained origin. Endoscopy revealed active diverticular bleeding in the second duodenal portion. A 61-year-old woman underwent endoscopic mucosal resection of superficial gastric adenocarcinoma, which was complicated with immediate bleeding. In all cases, the blood was washed out using a water-jet-equipped, single-channel gastroscope with a large working channel. The bleeding points were pinched and retracted with hemostatic forceps. Monopolar electrocoagulation was performed using an electrosurgical current generator. Hemostasis was achieved. No complications occurred. In conclusion, hemostatic forceps may be an effective as well as safe alternative approach for active GI bleeding of various origins.

Safe procedure in endoscopic submucosal dissection for colorectal tumors focused on preventing complications

Endoscopic submucosal dissection (ESD) is efficient for en bloc resection of large colorectal tumors. However, it has several technical difficulties, because the wall of the colon is thin and due to the winding nature of the colon. The main complications of ESD comprise postoperative perforation and hemorrhage, similar to endoscopic mucosal resection (EMR). In particular, the rate of perforation in ESD is higher than that in EMR. Perforation of the colon can cause fatal peritonitis. Endoscopic clipping is reported to be an efficient therapy for perforation. Most cases with perforation are treated conservatively without urgent surgical intervention. However, the rate of postoperative hemorrhage in ESD is similar to that in EMR. Endoscopic therapy including endoscopic clipping is performed and most of the cases are treated conservatively without blood transfusion. In blood examination, some degree of inflammation is detected after ESD. For the standardization of ESD, it is most important to decrease the rate of perforation. Adopting a safe strategy for ESD and a suitable choice of knife are both important ways of preventing perforation. Moreover, appropriate training and increasing experience can improve the endoscopic technique and can decrease the rate of perforation. In this review, we describe safe procedures in ESD to prevent complications, the complications of ESD and their management.

Outcome of endoscopic submucosal dissection for colorectal tumors in elderly people

BACKGROUND

Endoscopic submucosal dissection (ESD) has been reported to be effective for the en bloc resection of large colorectal tumors. Our study investigated whether ESD was suitable for elderly people with large colorectal tumors in terms of its invasiveness.

PATIENTS AND METHODS

We studied 119 colorectal tumors that were treated with ESD at Kyoto Prefectural University of Medicine or Nara City Hospital between 2006 and 2009. We classified each patient as either elderly, i.e., more than 75 years old, or non-elderly, i.e., less than 75 years old. Thirty-two of the cases were classified as elderly. Performance status, tumor size, operation time, rate of en bloc resection, histopathological diagnosis, complications, and hospital stay after ESD were analyzed retrospectively in both groups.

RESULTS

In the elderly group, the average tumor size was 32.6 mm; the average operation time, 96 min; the rate of en bloc resection, 81.2%; the rate of perforation, 3.1%; and hospital stay after ESD, 5.1 days. Histopathological diagnosis for 16 tumors was adenoma; for 13, carcinoma with invasion into the mucosa; and for three, carcinoma with invasion into the submucosa. There were no statistical differences between the two groups in any of these data. The case with perforation was treated conservatively without urgent surgery in the elderly group.

CONCLUSIONS

ESD for colorectal tumors resulted in favorable rates of en bloc resection in elderly people. Perforation occurred in elderly people, but these patients were cured with conservative treatment. ESD is a safe and minimally invasive treatment for elderly people with colorectal tumors.

In vitro porcine training model for colonic endoscopic submucosal dissection: an inexpensive and safe way to acquire a complex endoscopic technique

BACKGROUND

Colonic endoscopic submucosal dissection (ESD) has developed in recent years to permit en bloc resection of larger colorectal lesions that cannot be done by standard polypectomy or mucosal resection techniques. Colonic ESD is technically demanding and has a steep learning curve. Adequate training is essential to make ESD a reliable treatment for colorectal neoplasms. We aim to share our early experience with an in vitro porcine training model for colonic ESD.

METHOD

Resected porcine distal colon was used to set up a training model for ESD, which was performed as in human using a standard endoscope and dissecting devices. Size of the lesions, operation time, en bloc resection rate, and perforation rate were recorded.

RESULTS

Ten consecutive colonic ESD procedures were performed by a single endoscopist. Incomplete resection and perforation were encountered during the first two procedures. No perforation occurred in subsequent procedures and the operation time per task also decreased gradually. The setup cost for this model was only around US $30.

CONCLUSIONS

The in vitro porcine model is easy and inexpensive to set up. Our initial experience showed that the model could simulate colonic ESD in human and technical proficiency improved by repetition. This simple setup may be a promising training model for endoscopists working in areas with a low incidence of early gastric cancer.

A new breakthrough: ESD using a newly developed grasping type scissor forceps for early gastrointestinal tract neoplasms

Endoscopic submucosal dissection (ESD) has allowed the achievement of histologically curative en bloc resection of gastrointestinal neoplasms regardless of size, permitting the resection of previously non-resectable tumors. The ESD technique for treatment of early gastric cancer has spread rapidly in Japan and a few other Asian countries due to its excellent eradication rate compared to endoscopic mucosal resection. Although numerous electrosurgical knives have been developed for ESD, technical difficulties and high complication rates (bleeding and perforation) have limited their use worldwide. We developed the grasping type scissor forceps (GSF) to resolve such ESD-related problems. Our animal and preliminary clinical studies showed that ESD using GSF is a safe (no intraoperative complication) and technically efficient (curative en bloc resection rate 92%) method for dissection of early gastrointestinal tumors. The use of GSF is a promising option for performing ESD on early stage GI tract tumors both safely and effectively.

Efficacy of an endo-knife with a water-jet function (Flushknife) for endoscopic submucosal dissection of superficial colorectal neoplasms

OBJECTIVES

Endoscopic submucosal dissection (ESD) is currently not a common treatment for colorectal neoplasms because it is time consuming and technically difficult. Flushknife--an electrosurgical endo-knife with a water-jet function--is expected to reduce the difficulty of colorectal ESD. The objective of this study was to investigate the efficacy of a water-jet function for colorectal ESD.

METHODS

This study was a prospective randomized controlled trial, which was conducted at a cancer referral center. A total of 49 patients, with a total of 51 superficial colorectal neoplasms (median tumor size of 30 mm), were enrolled and randomly assigned to undergo ESD using either the Flexknife (electrosurgical endo-knife without a water-jet function) or the Flushknife. Tumors were resected by ESD using each endo-knife. The procedures were conducted by two endoscopists. Operation time was defined as the main outcome measure.

RESULTS

En bloc resection was achieved in 23 out of 26 (88%) lesions in the Flexknife group and in 24 out of 24 (100%) lesions in the Flushknife group. The mean operation time (95% confidence interval) was 87.3 (71.3-103.4) min in the Flexknife group and 61.0 (49.3-72.7) min in the Flushknife group (P=0.02). The Flushknife reduced the number of endoscopic device changes (P=0.001), the number of submucosal injections (P=0.001), and the mean amount of injected hyaluronate sodium (P=0.001) compared with the Flexknife. No severe adverse events were observed in either group.

CONCLUSIONS

Without increasing adverse events, the endo-knife with a water-jet function efficiently reduced the operation time of colorectal ESD in patients with large superficial colorectal neoplasms. (University hospital Medical Information Network Clinical Trials Registry number UMIN000001302).

Endoscopic submucosal dissection for colorectal epithelial neoplasms

PURPOSE

Endoscopic submucosal dissection permits removal of colorectal epithelial neoplasms en bloc, but long-term clinical outcomes remain unknown.

METHODS

Endoscopic submucosal dissection was performed in 282 patients having 296 colorectal tumors that fulfilled the inclusion criteria, which included lesions greater than 20 mm in size for which en bloc resection would be difficult with endoscopic mucosal resection, lesions with fibrotic scar due to previous endoscopic treatment or biopsies, locally residual lesions after endoscopic resection, or invasive carcinoma with slight submucosal penetration. En bloc or piecemeal resection, complete (en bloc with tumor-free lateral/basal margins) or incomplete resection, and complications were assessed, and factors related to each were analyzed using logistic regression. Patients with early colon cancer received endoscopic follow-up and metastatic surveys for a median of 34 months.

RESULTS

En bloc resection was achieved in 89.2% (264/296) and 234 lesions (79.1%) were deemed to have undergone complete resection. A right-side colonic location was the significant contributor to incomplete resection. Perforation was seen in 24 cases (8.1%) in association with tumor size and the presence of fibrosis. There was 1 case of locally recurrent tumor with incomplete resection, whereas neither recurrence nor residual disease was observed in the complete resection group. Neither cancer-related nor cancer-unrelated death was observed.

CONCLUSIONS

Precise assessment of curability with successful en bloc resection may reduce tumor recurrence after endoscopic submucosal dissection. The prognosis of early colorectal cancer in patients treated by endoscopic submucosal dissection is likely to be excellent, although further longer follow-up studies are warranted.

Is endoscopic closure with clips effective for both diagnostic and therapeutic colonoscopy-associated bowel perforation?

BACKGROUND

Colonic perforation is an uncommon but serious colonoscopy-associated complication. This study assessed the effectiveness of conservative management with endoscopic clipping for colonoscopy-associated perforations.

METHODS

Clinical manifestations and management outcomes were assessed for 38 patients with colonoscopy-associated colonic perforations that occurred between January 2001 and April 2008 at the Asan Medical Center, Seoul, Korea. These perforations were classified as endoscopically evident, endoscopically suspected, and radiologically proven.

RESULTS

Of the 38 perforations, 19 were endoscopically evident, 9 were endoscopically suspected, and 10 were radiologically proven but without endoscopic evidence. Of the 19 patients with endoscopically evident perforations, 13 (68.4%) underwent endoscopic closure with clips, and all improved without surgery. All nine patients with endoscopically suspected perforations underwent endoscopic closure, and eight (88.9%) improved without surgery. Of the 10 radiologically proven perforations, 7 were detected within 1 day after colonoscopy. All the patients improved without surgery. However, two of the three patients with delayed perforations required emergency laparotomy. Consequently, of the 38 patients with perforations, 29 (76.3%) improved without surgery. Of the 28 patients with endoscopically evident or suspected perforations, conservative management was successful for 21 (95.5%) of the 22 patients with effective clipping, but for none (0%) of the 6 patients without clipping.

CONCLUSIONS

Conservative management by immediate endoscopic closure with clips can be effective for the treatment of colonic perforations detected during colonoscopy. Conservative management also may be tried cautiously for stable patients who have radiologically proven colonoscopy-associated perforations without endoscopic evidence.

Endoscopic submucosal dissection for colorectal neoplasms

Although endoscopic submucosal dissection (ESD) gains acceptance as one of the standard treatments for esophageal and stomach neoplasms in Japan, it is still in the developing stage for colorectal neoplasms. In terms of indications, little likelihood of nodal metastasis and technical resectability are principally considered. Some of intramucosal neoplasms, carcinomas with minute submucosal invasion, and carcinoid tumors, which are technically unresectable by conventional endoscopic treatments, may become good candidates for ESD, considering substantial risks and obtained benefits. ESD as a staging measure to obtain histological information of the invasion depth and lymphovascular infiltration is acceptable because preoperative prediction is difficult in some cases. In terms of techniques, advantages of ESD in comparison with other endoscopic treatments are to be controllable in size and shape, and to be resectable even in large and fibrotic neoplasms. The disadvantages may be longer procedure time, heavier bleeding, and higher possibility of perforation. However, owing to refinement of the techniques, invention of devices, and the learning curve, acceptable technical safety has been achieved. Colorectal ESD is very promising and become one of the standard treatments for colorectal neoplasms in the near future.

Can magnification endoscopy detect residual adenoma after piecemeal resection of large sessile colorectal lesions to guide subsequent treatment? A prospective single-center study

PURPOSE

This study assesses the ability of magnification endoscopy to detect residual adenomatous tissue after endoscopic piecemeal resection of colorectal polyps and evaluates the impact of the technique on the incidence of recurrence.

METHODS

Patients who underwent endoscopic piecemeal resection for large (>2 cm) sessile colorectal polyps were included. After endoscopic piecemeal resection, both the outer resection margins and the central severed area were inspected with magnification endoscopy. Completeness of excision as determined from the magnified surface pattern was compared with that determined histologically. Areas of incomplete resection were treated with additional resection or argon plasma coagulation.

RESULTS

A total of 77 lesions were resected. Mean size of the resected lesions was 29 +/- 6 mm (range, 23-60). Complications of resection occurred in eight patients (seven had immediate bleeding that was successfully managed with hemoclip application, and one had delayed perforation that was treated surgically). The sensitivity of magnification endoscopy for predicting remnant adenoma at resection margins was 98% (95% confidence interval 90-100); specificity was 90% (95% confidence interval 79-100). Overall accuracy was 94.5% (95% confidence interval 87.2-98.6). On a mean follow-up of 32 months (range, 18-46) the recurrence rate was 2.6%.

CONCLUSIONS

Magnification endoscopy is accurate at predicting remnant tissue after endoscopic piecemeal resection of large sessile colorectal polypoid lesions. When applied on both outer margins and inner portions of the severed area, it is helpful as a guide to subsequent further treatment to decrease recurrence.

Endoscopic submucosal dissection for colorectal tumors

BACKGROUND

Endoscopic submucosal dissection (ESD) is a state-of-the-art method that enables resection of larger tumors than those resectable by conventional endoscopic mucosal resection (EMR). However, the individual role of each method in the treatment of colorectal tumors remains undetermined.

OBJECTIVE AND METHODS

To consider the respective indications of ESD and EMR for colorectal tumors, we analyzed the results of the two treatments retrospectively.

RESULTS

Tumors treated by ESD (44 tumors) were significantly larger, more often located in the rectum and more often coexistent with cancer than those treated by EMR (512 tumors). EMR was used in the majority of adenomas, and showed high rates of both one-piece resection (OPR) and complete resection (CR) for adenomas less than 20 mm. However, for adenomas and cancers greater or equal to 20 mm, the CR rate for EMR was significantly lower than that for ESD because of the incidence of OPR with a positive lateral margin (16% vs 0% with ESD vs EMR). Histopathology (cancer), size (> or =20 mm) and macroscopic type (laterally spreading tumors) were shown to be significant risk factors for that incidence. For tumors with these factors, ESD showed a higher CR rate than did EMR. However, ESD required longer operating times and tended to have a higher rate of perforation compared with EMR. ESD was aborted halfway in seven cases due to technical difficulties and perforation.

CONCLUSION

ESD and EMR have different characteristics as treatment for colorectal tumors. Careful evaluation of the lesion and of the balance between benefits and risks are mandatory before selecting either of these treatments for colorectal tumors.

Application of endoscopic submucosal dissection for removal of deep invasive submucosal colon carcinoma

Endoscopic submucosal (sm) dissection (ESD) is a recently used technique that enables en-bloc resection of large colorectal tumors allowing a more precise histopathological analysis of the resected specimen. However, it has not been widely adopted even in Japan mainly due to its technical difficulty and increased risk of perforation. Herein, we present an ESD-treated lesion with deep sm invasion removed without complications, such as bleeding or perforation, from a patient at high-risk for surgical intervention. A successful ESD was achieved although the sm invasion was greater than 1000 mum from the muscularis mucosae, and the nonlifting sign was positive. It is our belief that this procedure should be performed at least in patients at high-risk for surgical intervention. At present, we have removed 16 lesions with deep sm invasion by ESD without complications, demonstrating that deep sm cancer can be successfully resected by this technique as a local resection. Herein, we report on one of these cases.

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 > or = 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.

Endoscopic mucosal resection for early colorectal neoplasia: pathologic basis, procedures, and outcomes

Open access endoscopy and screening programs enable detection and removal of an increased number of colon polyps in the early stages of neoplastic transformation. Unfortunately, polyps larger than 3 cm, involving more than one-third of circumference or two haustral folds, or with a flat/depressed morphology are more challenging to remove with standard polypectomy techniques. Endoscopic mucosal resection potentiates the removal, in a minimally invasive way, of certain colonic lesions that would otherwise require surgical or ablative treatment. Because the plane of resection during endoscopic mucosal resection is typically the middle to deep submucosal layer, compared with standard polypectomy, which normally provides resection at a mucosal level, endoscopic mucosal resection offers the advantage of providing en bloc resection specimens for histopathologic analysis. Indications to perform endoscopic mucosal resection are adenoma and small, well-differentiated carcinoma, confined to the mucosa or with minimal invasion to submucosa, and without any invasion to lymphatic channels or vessels. The most frequently reported major complications, such as perforation (0-5%) and bleeding (0.5-6%), may be controlled by endoscopic methods and rarely require surgical treatment. Follow-up postendoscopic mucosal resection is essential because of the risk of neoplastic recurrence.

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.

Knack and practical technique of colonoscopic treatment focused on endoscopic mucosal resection using snare

Endoscopic mucosal resection (EMR) is one of the main treatment modalities for broad-based protruded-type or flat-type lesions of colorectal tumors. In this report, the procedures and skills required for EMR, which forms the basis of colonoscopic treatment, are described based on the current situation. The knack of EMR is to understand the characteristics and selection of an adequate snare in each situation, selection of adequate local injection drug, to learn techniques of local injection, to master skilful snaring techniques, to estimate the degree of radial cure of locally resected regions using magnifying observation and the practice of additional trimming. As a result of the practice and learning of these points, EMR, including piecemeal resection, can be enough for curative treatment of colorectal tumor. We can and should differentiate EMR from endoscopic submucosal dissection (ESD) for various types of colorectal tumor according to detailed endoscopic diagnosis using magnification prior to treatment.

Therapeutic strategy for colorectal laterally spreading tumor

Most colorectal tumors larger than 20 mm in diameter are called laterally spreading tumors (LST), most of which are adenomatous lesions. Laterally spreading tumors are classified into two types according to their morphology, granular type (LST-G) and non-granular type (LST-NG). Each type has two subtypes. The former consists of a 'homogenous type' and a 'nodular mixed type', while the latter consists of a 'flat elevated (FE) type' and a 'psedodepressed (PD) type'. In LST-G and LST-NG FE types, type V pit pattern with magnification enables the recognition of the carcinomatous or submucosal invasive area. Most of these adenomatous large lesions can be cured by scheduled endoscopic piecemeal mucosal resection (EPMR). However, LST-G with large whole nodular type or type V pit pattern, which cannot be resected en bloc with a snare, is an indication for endoscopic submucosal dissection (ESD). The LST-NG PD has a high frequency of submucosal invasion and the submucosal invasive area cannot be recognized correctly in the pseudodepression with magnification prior to endoscopic treatment. Therefore, en bloc resection with ESD should be applied to LST-NG PD. The therapeutic strategy for choosing between EPMR and ESD for large LST lesions should therefore be determined based on the macroscopic findings of their subtype and pit pattern findings.

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.

Sentinel node biopsy for the individualization of surgical strategy for cure of early-stage colon cancer

INTRODUCTION

The requirement for nodal analysis currently confounds the oncological propriety of focused purely endoscopic resection for early-stage colon cancer and complicates the evolution of innovative alternatives such as natural orifice transluminal endoscopic surgery (NOTES) and its hybrids. Adjunctive sentinel node biopsy (SNB) deserves consideration as a means of addressing this shortfall.

METHODS

Data from two prospectively maintained databases established for multicentric studies of SNB in colon cancer that employed similar methodologies were pooled to establish technique potency selectively in T1/T2 disease (both overall and under optimized conditions) and to project potential clinical impact.

RESULTS

Of 891 patients with T1-4, M0 intraperitoneal colon cancer, 225 had T1/T2 disease. Sentinel nodes were either not found or were falsely negative in 18 patients with T1/T2 cancers (8%) as compared with 17% (112/646) in those with T3/T4 disease (P = 0.001). Negative predictive value (NPV) in the former exceeded 95%, while sensitivity [including immunohistochemistry (IHC)] was 81%. In the 193 patients with T1/T2 disease recruited from those centers contributing >22 patients, sensitivity was 89% and NPV 97%. Thus, in this cohort, SNB could have correctly prompted localized resection (obviating en bloc mesenteric dissection) in 75% (144) of patients, including 59 with T1 lesions potentially amenable to intraluminal resection alone as their definitive treatment. Forty-four patients (23.4%) would still have conventional resection, leaving three patients (1.6% overall) understaged (11% false-negative rate).

CONCLUSION

These findings support the further investigation of SNB as oncological augment for localized resective techniques. Specific prospective study should pursue this goal.

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 submucosal dissection of early cancers, flat adenomas, and submucosal tumors in the gastrointestinal tract

BACKGROUND & AIMS

Endoscopic submucosal dissection (ESD) is a promising technique in the treatment of large premalignant and early malignant gastrointestinal lesions. In contrast to Japan and Asian countries, few data are available from Western countries. The objective of this study was to assess the feasibility of ESD in a European center, with special regard for the success rate and learning curve.

METHODS

Over a 4-year-period, 82 epithelial or submucosal lesions were referred for ESD. Seventy-one ESDs were performed (51 gastric, 17 rectal, 2 esophageal, and 1 duodenal). Resection rates, procedure times, specimen sizes, complications, and recurrences were noted. The mean follow-up period was 15 months.

RESULTS

Specimen size increased significantly (P < .05) and procedural duration decreased significantly (P < .005) over time. En bloc resection rates and R0 en bloc resection rates were 77.1% and 65.7%, respectively, in the first half of the study and increased to 86.1% and 72.2%, respectively, in the second half (P = NS). No recurrence was observed after R0 en bloc resection whereas the recurrence rate was 38.5% after piecemeal resections (P < .001). Two perforations in the first series were treated by surgery; 2 other perforations, 8 minor bleedings, and 2 pyloric stenoses were treated endoscopically.

CONCLUSIONS

ESD is technically feasible and shows promising results in this German single-center-study. ESD is time consuming and difficult but shows a learning curve resulting in a decrease of the procedural duration over time. R0 en bloc resection is mostly possible and can avoid the risk of local recurrence.

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.

Could lymphatic mapping and sentinel node biopsy provide oncological providence for local resectional techniques for colon cancer? A review of the literature

BACKGROUND

Endoscopic resectional techniques for colon cancer are undermined by their inability to determine lymph node status. This limits their application to only those lesions at the most minimal risk of lymphatic dissemination whereas their technical capacity could allow intraluminal or even transluminal address of larger lesions. Sentinel node biopsy may theoretically address this breach although the variability of its reported results for this disease is worrisome.

METHODS

Medline, EMBASE and Cochrane databases were interrogated back to 1999 to identify all publications concerning lymphatic mapping for colon cancer with reference cross-checking for completeness. All reports were examined from the perspective of in vivo technique accuracy selectively in early stage disease (i.e. lesions potentially within the technical capacity of endoscopic resection).

RESULTS

Fifty-two studies detailing the experiences of 3390 patients were identified. Considerable variation in patient characteristics as well as in surgical and histological quality assurances were however evident among the studies identified. In addition, considerable contamination of the studies by inclusion of rectal cancer without subgroup separation was frequent. Indeed such is the heterogeneity of the publications to date, formal meta-analysis to pool patient cohorts in order to definitively ascertain technique accuracy in those with T1 and/or T2 cancer is not possible. Although lymphatic mapping in early stage neoplasia alone has rarely been specifically studied, those studies that included examination of false negative rates identified high T3/4 patient proportions and larger tumor size as being important confounders. Under selected circumstances however the technique seems to perform sufficiently reliably to allow it prompt consideration of its use to tailor operative extent.

CONCLUSION

The specific question of whether sentinel node biopsy can augment the oncological propriety for endoscopic resective techniques (including Natural Orifice Transluminal Endoscopic Surgery [NOTES]) cannot be definitively answered at present. Study heterogeneity may account for the variability evident in the results from different centers. Enhanced capacity (perhaps to the level necessary to consider selective avoidance of en bloc mesenteric resection) by its confinement to only early stage disease is plausible although not proven. Specific study of the technique in early stage tumors is clearly essential before proffering this approach.

Acute intestinal obstruction after endoscopic submucosal dissection: report of a case

The endoscopic submucosal dissection is a novel noninvasive therapeutic procedure for the early stage colorectal neoplasm. Endoscopic submucosal dissection has an advantage over endoscopic mucosal resection by en bloc resection of the mucosal lesion regardless of the size. As endoscopic submucosal dissection becomes popular, the rate of complication is expected to increase. Although uncommon, complications of endoscopic submucosal dissection have been reported including hemorrhage and perforation. Acute colon obstruction is a very rare complication of endoscopic submucosal dissection, but can be potentially lethal if the diagnosis is delayed. We report a case of acute intestinal obstruction after ESD of early colon cancer located in the cecal base.

Perspective on the practical indications of endoscopic submucosal dissection of gastrointestinal neoplasms

Endoscopic submucosal dissection (ESD) is a new endoluminal therapeutic technique involving the use of cutting devices to permit a larger resection of the tissue over the muscularis propria. The major advantages of the technique in comparison with polypectomy and endoscopic mucosal resection are controllable resection size and shape and en bloc resection of a large lesion or a lesion with ulcerative findings. This technique is applied for the endoscopic treatment of epithelial neoplasms in the gastrointestinal tract from the pharynx to the rectum. Furthermore, some carcinoids and submucosal tumors in the gastrointestinal tract are treated by ESD. To determine the indication, two aspects should be considered. The first is a little likelihood of lymph node metastasis and the second is the technical resectability. In this review, practical guidelines of ESD for the gastrointestinal neoplasms are discussed based on the evidence found in the literature.

Endoscopic submucosal dissection for gastrointestinal neoplasms

Endoscopic submucosal dissection (ESD) is an advanced technique of therapeutic endoscopy for superficial gastrointestinal neoplasms. Three steps characterize it: injecting fluid into the submucosa to elevate the lesion, cutting the surrounding mucosa of the lesion, and dissecting the submucosa beneath the lesion. The ESD technique has rapidly permeated in Japan for treatment of early gastric cancer, due to its excellent results of en-bloc resection compared to endoscopic mucosal resection (EMR). Although there is still room for improvement to lessen its technical difficulty, ESD has recently been applied to esophageal and colorectal neoplasms. Favorable short-term results have been reported, but the application of ESD should be well considered by three aspects: (1) the possibility of nodal metastases of the lesion, (2) technical difficulty such as location, ulceration and operator’s skill, and (3) organ characteristics.

Lymphatic mapping and sentinel node biopsy in the colonic mesentery by Natural Orifice Transluminal Endoscopic Surgery (NOTES)

INTRODUCTION

Although intraluminal and transluminal techniques can achieve localized resection of early-stage alimentary tumours, they do not designate the status of the filtering mesenteric lymph nodes. Natural orifice transluminal endoscopic surgery (NOTES) may however effect sentinel node biopsy from within the peritoneum.

METHODS

A transgastric NOTES technique was utilized in six pigs. A conventional double-channel gastroscope created both the 12mm anterior gastrotomy and the pneumoperitoneum and enabled peritoneoscopy. The sigmoid colon was fully exposed by an intracolonic magnet under extracorporeal control. Colonoscopy facilitated submucosal injection of methylene blue dye (3 ml) at the apex of the sigmoid loop under direct transgastric vision. The mesocolon was searched for blue-stained lymph channels and nodes, the latter being resected and retrieved by the intraperitoneal endoscope. At procedure end, three pigs underwent immediate laparotomy for scrutiny of the operation site while three were survived for forensic laparotomy on postoperative day 14.

RESULTS

Each procedure was a technical success. Gastrotomy, pneumoperitoneum, peritoneoscopy and sigmoid exposure were promptly achieved (mean 9.2 min). Post-injection, blue lymphatics identifying specific nodes were immediately appreciable and these could be dissected cleanly and retrieved intact per oram. Mean lymphadenectomy time was 19 (range 12-32) min. All survival animals thrived during convalescence. At laparotomy, there was neither mesentery penetration, bowel ischemia nor mesenteric hematoma/hemorrhage in any pig and no residual blue stained nodes in those sacrificed early.

CONCLUSION

Sentinel node biopsy can be performed without abdominal wall transgression. Thus potentially the oncological proprietary of local resectional techniques may be augmented while preserving their ideals and dividends.

Endoscopic mucosal resection of colonic lesions: current applications and future prospects

The introduction of submucosal fluid injection has remarkably extended the range of endoscopically resectable polyps. The limiting factor for endoscopic resection is not polyp size, but polyp depth. Endoscopic ultrasound is a useful adjunctive diagnostic tool to assess the depth of invasion. The success of are section ultimately depends on pathologic confirmation of a benign nature of this lesion or of a cancer limited to the mucosa. Selected well-differentiated cancers without lymphovascular invasion of the superficial submucosa can be successfully resected endoscopically.