Large Sessile Research Articles

Population structure of two deep sea tubeworms, Lamellibrachia luymesi and Seepiophila jonesi, from the hydrocarbon seeps of the Gulf of Mexico

Vestimentiferan tubeworms are a group of large sessile marine polychaete annelids (family Siboglinidae) found in the regions of hydrothermal venting or seepage of the reduced chemical hydrogen sulfide. Hydrocarbon seeps on the Louisiana Slope of the Gulf of Mexico support large communities of the co-occurring vestimentiferan species Lamellibrachia luymesi and Seepiophila jonesi. These sessile species have the opportunity to disperse between the patchy sites of active seepage on the seafloor during a planktonic larval stage. However, it is unclear whether dispersal occurs at a local or global scale. Four ( L. luymesi) and seven ( S. jonesi) microsatellite loci were used to test for population substructure among ten hydrocarbon seep sites on the Louisiana Slope. Both species showed high levels of allelic diversity, averaging 18.5 ( L. luymesi) and 22 ( S. jonesi) alleles/locus, respectively, and high observed heterozygosity at all microsatellite loci (0.71–0.9 in L. luymesi, 0.27–0.84 in S. jonesi). The two species showed a significant deficiency in heterozygotes compared to that predicted under the Hardy–Weinberg equilibrium. L. luymesi showed a small but significant amount of population structure, with a positive correlation between genetic and geographic distance among the sample sites spanning 540 km. S. jonesi, in contrast, showed no evidence for isolation by distance, but did show a significant genetic difference between aggregations of different ages. These results suggest that these two species differ in how larvae are able to colonize new seep sites through space ( L. luymesi) and though time ( S. jonesi).

Efficacy, Safety and Outcomes of ‘Inject and Cut’ Endoscopic Mucosal Resection for Large Sessile and Flat Colorectal Polyps

Background and Study Aims: The study examines the outcomes of the ‘inject and cut’ endoscopic mucosal resection (EMR), for large sessile and flat colorectal polyps. Patients and Methods: Between January 2006 and December 2008 all patients referred to our institution for EMR of large polyps were prospectively evaluated. The accuracy of lifting sign and the rate of en bloc and piecemeal resection, complications and recurrence were analyzed. Results: A total of 157 patients with 182 lesions (median size 24.7 ± 10.2 mm) were included in the study. The most frequent location was the sigmoid colon in 30.2%. Because of non-lifting sign, 5/182 lesions were referred to surgical resection and 177 (43 flat and 134 sessile) were resected, 79 (44.6%) en bloc and 98 (55.4%) piecemeal. There were 20 procedural (11.3%) and 2 late (1.1%) bleeding, 4 post-polypectomy syndrome (2.2%) and 2 perforations (1.1%). Bleeding was related to malignancy (p = 0.01). Intramucosal cancer was observed in 5 cases (2.8%) while invasive cancer was seen in 8 (4.5%). Malignancy was related to polyp size ≧30 mm (p = 0.002). Follow-up colonoscopy was performed in 147 patients with 172 EMR for a mean of 19.8 months. Recurrence was observed in 12/172 (6.9%) polyps. Conclusion: Inject and cut EMR is practical and effective with a low risk of complication and local recurrence.

PTU-006 Large colonic polyps detected during bowel cancer screening—a retrospective review of treatment and outcomes: Abstract PTU-006

<h3>Introduction</h3> Bowel cancer is the third most common cancer in the UK, with approximately 16 100 deaths per annum. The Norfolk and Norwich University Hospital was one of the first sites in the country to introduce the bowel cancer screening (BCS) programme. It offers men and women aged between the ages of 60 and 69 an initial screening via a faecal occult blood test. Those with an abnormal result are then offered a colonoscopy. Large (&gt;2 cm) polyps are uncommon in routine practise however with the development of the BCS programme are now more readily encountered. <h3>Methods</h3> To assess the success and safety of endoscopic resection of large (&gt;2 cm) colorectal polyps in the context of the BCS programme. Records of all patients who had a polyp &gt;2 cm were identified using the BCS database. We analysed data from a 3-year period starting from July 2006 until July 2009. We looked at polyp location, morphology, completeness of resection, complications and histological staging. <h3>Results</h3> 135 polyps &gt;2 cm were detected in 127 patients with a mean size of 3 cm (spread 2–7 cm). 17.8% (24/135) were thought to be invasive by the endoscopist and all of these were biopsied. 12.5% of these biopsied polyps were found to be adenocarcinoma/carcinoma in situ. 11.9% (16/135) of all polyps were adenocarcinoma. 31.9% (43/135) of polyps were sessile, and 68.9% (92/135) were pedunculated. 94.1% (127/135) of polyps were left sided. 82.2% (111/135) of polyps were removed at the time of the initial endoscopy. Of these 22.5% were sessile and 77.5% pedunculated. 20% of the sessile polyps had further treatment by means of either surgery (12%,3/3 benign disease) or repeat polypectomy (8%) for residual polyp tissue. In comparison 8.1% of pedunculated polyps went on to have either surgery (5.8%, 4/5 adenocarcinoma) or repeat polypectomy (2.3) for residual polyp tissue. There were no carcinomas detected in those polyps measuring &gt;5 cm. However the greatest percentage of adenocarcinomas were found in pedunculated polyps measuring 4049 mm. Three patients required endoscopic therapy for bleeding at the time of polypectomy and two patients were admitted as a precaution. Three patients had immediate bleeding following polypectomy which was controlled endoscopically at the time of initial endoscopy. Two of these patients were admitted overnight as a precaution. There were no cases of perforation, no late bleeds and no readmissions. <h3>Conclusion</h3> Our series demonstrates that endoscopic therapy for large pedunculated and sessile colorectal polyps is a safe and effective treatment with minimal morbidity and no mortality. We found that despite experienced endoscopists performing colonoscopy it was difficult to predict which polyps are malignant. However large pedunculated polyps seem to carry a significant malignant potential.

W1447: Endoscopic Mucosal Resection and Modified Endoscopic Submucosal Dissection for Removal of Large Sessile Colonic Polyps: 1-Year Single Operator Experience in the USA

Development of endoscopic submucosal dissection (ESD) in Japan enabled endoscopic removal of large sessile and flat colonic polyps. However, ESD technique is difficult and requires accessories which are not readily available in the USA.

S1527: Lesion Morphology, Paris Classification and Pit Pattern but Not Size Predict and Stratify Risk of Submucosal Invasive Adenocarcinoma Within Laterally Spreading Tumors (LSTs) and Large Sessile Colonic Polyps in a Multicenter Setting: Results of the Australian Colonic Endoscopic Mucosal Resection (ACE) Study

S1527: Lesion Morphology, Paris Classification and Pit Pattern but Not Size Predict and Stratify Risk of Submucosal Invasive Adenocarcinoma Within Laterally Spreading Tumors (LSTs) and Large Sessile Colonic Polyps in a Multicenter Setting: Results of the Australian Colonic Endoscopic Mucosal Resection (ACE) Study

347h: Predictors of Therapeutic Success for Endoscopic Mucosal Resection (EMR) of Laterally Spreading Tumours (LSTs) and Large Sessile Colonic Polyps: Results of the Prospective, Multicenter Australian Colonic EMR (ACE) Study

347h: Predictors of Therapeutic Success for Endoscopic Mucosal Resection (EMR) of Laterally Spreading Tumours (LSTs) and Large Sessile Colonic Polyps: Results of the Prospective, Multicenter Australian Colonic EMR (ACE) Study

347l: Modification of Submucosal (SM) Injection Solution Significantly Improves Technical Outcomes in Colonic Endoscopic Mucosal Resection (EMR): A Randomized, Double-Blind Controlled Trial of Succinylated Gelatin (SG) Versus Normal Saline for EMR of Laterally Spreading Tumours (LSTs) and Large Sessile Lesions of the Colon

SG (Gelofusine®, B.Braun, Switzerland) is a clear, inexpensive, safe, colloidal plasma volume expanding solution that is commonly used for hypovolaemia. When compared to normal saline (NS) for SM injection in a porcine model, SG provided superior vertical elevation of the lesion resulting in a 42% increase in EMR specimen size. The present study is the first to investigate SG for human colonic EMR.

A new serrated snare for improved tissue capture during endoscopic snare resection

Endoscopic snare resection of gastrointestinal polyps and neoplasm is a standard procedure in interventional endoscopy. Due to technical and procedural improvements the removal of large sessile polyps can be achieved by endoscopic mucosal resection either in one single specimen or by piecemeal resection. In this experimental study a new snare with special teeth attached to the distal part of the wire loop was evaluated and compared to a conventional snare. Seventy artificial sessile tumors were created in a standardized manner in a porcine ex vivo colon. Thirty-five polyps were resected with the new serrated snare, whilst the other 35 polyps were removed using an identical snare without teeth. The weight measurement of the resected polyps showed that when using the new serrated snare 31% more tissue could be removed with a single snare resection in comparison with the conventional snare without teeth (mean 454 mg vs. 347 mg, ±202 mg vs. ±165 mg). The teeth obviously increased the effectiveness of snare resection by avoiding the accidental loss of entrapped tissue from the loop. The new snare hopes to faciliate the removal of flat polyps and to reduce the number of specimens during piecemeal resection to a minimum, allowing a better histopathological assessment.

Recurrence after endoscopic piecemeal mucosal resection for large sessile colorectal polyps

To evaluate the safety and outcomes of endoscopic piecemeal mucosal resection (EPMR) for large sessile colorectal polyps. The patients enrolled in this study were 47 patients with 50 large sessile polyps (diameter, 2 cm or greater) who underwent EPMR using a submucosal saline injection technique between December 2002 and October 2005. All medical records, including characteristics of the patients and polyps, complications, and recurrences, were retrospectively reviewed. The first follow-up endoscopic examination was performed at 3-6 mo after initial endoscopic resection, and the second at 12 mo post-EPMR. Subsequent surveillance colonoscopic examinations were individualized, taking risk factors into account. The patients were 23 men and 24 women, with a mean age of 60 years. Mean polyp size was 30.1 mm. Of 50 polyps identified, 34 (68%) were benign and 16 (32%) were malignant. There were 6 (12%) cases with EPMR-related bleeding: 5 intra-procedural and 1 early post-procedural bleeding. All bleeding episodes were managed by endoscopic clipping or argon beam coagulation. There were no perforations. Recurrence was identified in 5 cases (12.2%): 4 local recurrences detected at 3 mo post-EPMR and 1 local recurrence detected at 14 mo post-EPMR. The recurrence rate after EPMR was 3.1% for benign polyps and 33.3% for malignant polyps (P < 0.05). Median follow-up time was 37 mo. EPMR is safe, but should be applied carefully in malignant polyps. Close follow-up endoscopic examinations are necessary for early detection of recurrence.

Brachiopod faunas across the Wuchiapingian-Changhsingian (Late Permian) boundary at the stratotype section and subsurface of Changxing area, South China

This paper describes 18 species in 15 brachiopod genera from the Wuchiapingian/Changhsingian (W/C) boundary beds at its stratotype section and subsurface succession of the Changxing areas, Zhejiang, South China. The late Wuchiapingian brachiopods of the Changxing areas are dominated by large species such as Tyloplecta yangtzeensis, Niutoushania niutoushanensis, Edriosteges poyangensis, Orthothetina ruber, and Permophricodothyris grandis. These elements also characterize the Wuchiapingian faunas across the entire South China. The early Changhsingian assemblage is dominated by the Wuchiapingian holdovers and characterized by abundant small, thin-shelled chonetides or chonetid-like productides. The W/C transition saw a change from the abundant and diverse late Wuchiapingian fauna to the restricted and impoverished assemblage in the early Changhsingian. This distinct faunal changeover may be primarily accounted by the end-Wuchiapingian regional transgression in South China. This transgression event flooded most shallow-water niches of the Changxing areas so that most of the large sessile elements suffered the loss of shallow-water habitats. In contrast, the widespread, widely adaptive opportunitists survived into the Changhsingian. The Wuchiapingian brachiopod faunas across the entire South China are comparable one another, while the Changhsingian faunas were strongly controlled by depositional settings, and both the shallow-water and deep-water assemblages are very distinct each other.

Can Magnification Endoscopy Detect Residual Adenoma After Piecemeal Resection of Large Sessile Colorectal Lesions to Guide Subsequent Treatment? A Prospective Single-Center Study

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. 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. 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%. 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 mucosal resection for large and giant sessile and flat colorectal polyps: a single-center experience with long-term follow-up

This study examines efficacy, outcome, and complications of endoscopic mucosal resection (EMR) for large (> or = 20 mm) and giant (> or = 40 mm) sessile and flat colorectal polyps. All EMRs carried out at our institution over a 9-year period, for large and giant sessile and flat colorectal polyps with an intensive and regular follow-up were evaluated. The rate of en bloc and piecemeal resection, complications, and recurrence were analyzed. A total of 148 polyps were resected in 148 patients. There were 113 large polyps (76.3 %) with a mean size of 25 +/- 4.7 mm (range 20 - 39 mm) and 35 giant polyps (23.7 %) with a mean size of 48.8 +/- 12.5 mm (range 40 - 100 mm). The most frequent location was the rectum, occurring in 43.2 %. All lesions were removed in a single session. En bloc resection was performed in 65 cases (43.9 %) and piecemeal in 83 (56.1 %). Procedural bleeding occurred in 13 EMRs (8.8 %), and one case of early and one case of delayed bleeding also occurred. There were two cases of postpolypectomy syndrome and one case of perforation. Malignancy (intramucosal and invasive cancer) was mostly present in polyps with sessile shape ( P = 0.0013). Follow-up colonoscopy was performed in 142 patients for a mean of 29.8 months. Recurrence was observed in 6/142 (4.2 %) patients and was found more in patients with giant polyps ( P = 0.014). In our experience EMR is a simple and safe procedure for removing large and giant sessile and flat colorectal polyps, and is associated with a very low risk of complication and local recurrence.

Endoscopic transanal resection of rectal adenomas using the urological resectoscope

Large sessile rectal adenomas are often difficult to excise and several different techniques have been described. This study evaluates the results of adenoma excision by endoscopic transanal resection using the urological resectoscope by a single surgeon in a UK district general hospital. Between January 1989 and November 2004, data on all patients treated by endoscopic transanal resection of benign rectal tumours using a urological resectoscope (ETAR) were prospectively collected and analysed. Forty patients (50% male, median age 72 years) underwent a total of 81 endoscopic transanal resections. The tumour characteristics were: size > 2 cm (83%), location in lower 2/3 of rectum (83%) and extensive circumferential carpet-like appearances (13%). Fifty percent of the patients required only one procedure to achieve clearance. Mean operative time was 26 min (range 10-65 min). Seventy-eight percent of the patients were discharged home within 24 h. Postoperative morbidity was 8% and in-hospital mortality was zero. Histology revealed severe dysplasia in 48% of the tumours and five patients were incidentally found to have foci of rectal adenocarcinoma. With a median follow-up of 47 months (range 2-162 months), local recurrences occurred in 13% (n = 5) of patients. All, except one, were treated successfully with further endoscopic transanal resections. ETAR is simple and safe for managing rectal adenomas.

CURRENT STATUS OF COLONIC ENDOSCOPIC MUCOSAL RESECTION IN THE WEST AND THE INTERFACE WITH ENDOSCOPIC SUBMUCOSAL DISSECTION

Endoscopic Mucosal Resection (EMR) is now widely practised by western endoscopists to treat large sessile colonic polyps or laterally spreading tumours. Despite its widespread application, the technique of colonic EMR is not standardised. A lesion specific endoscopic treatment approach is also lacking. For lesions larger than 25mm, EMR is limited by its inability to achieve en-bloc resection. En-bloc resection has many theoretical advantages including more accurate histological assessment, reduced recurrence and potentially curative treatment for low risk submucosal invasive neoplasia particularly in patients with significant co-morbidity. Hence, Japanese endoscopists, having pioneered endoscopic submucosal dissection (ESD) in the upper gastrointestinal tract for the en-bloc resection of superficial neoplasia, now advocate the use of ESD for laterally spreading tumours of the colon greater than 25-30mm. This treatment strategy is not widely accepted or practised in the west and has its own inherent problems. The absence of suitable gastric lesions on which to develop ESD skills is also another significant barrier to the development of colonic ESD. It is also possible that modification and refinement in EMR technique may increase the size limit for colonic EMR.

Successful Complete Cure En-Bloc Resection of Large Nonpedunculated Colonic Polyps by Endoscopic Submucosal Dissection: A Meta-Analysis and Systematic Review

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. 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. 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. 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.

Endoscopic submucosal dissection of large sessile colorectal adenomas

Endoscopic submucosal dissection of large sessile colorectal adenomas

Endoscopic Submucosal Dissection of Early Colorectal Neoplasm

Introduction: EMR is safe and useful technique for colorectal laterally spreading tumor(LST) and large sessile tumor. However it is difficult to perform the en bloc resection of the tumor>20 mm. Local recurrence was often observed for these lesions. Patients and Methods: The aim of study is to evaluate clinical outcome and feasibility of colorectal endoscopic submucosal dissection(ESD). 40 colorectal consecutive lesions(40 patients) were enrolled in this study. Indication criteria for colorectal ESD is VI pit pattern in magnification colonoscopy, and non-granular type(LST-NG) and mixed nodular type (LST-G(mix)) of LST, and large protruded lesion(>30 mm) in macroscopic type. ESD procedure: injection of grycerol and sodium hyarulonate acid, circumferential incision and submucosal dissection was performed by Flush knife. All cases performed by single colonoscopist(K.S) with CO2 insufflation. Massively submucosal invasive carcinoma(SM-M) was defined as over an invasion depth of 1000μm. Results: The average diameter of lesions was 31.2 ± 13.6. 4 lesions were located in the cecum, 2 in the ascending colon, 9 in the transverse colon, 2 in the descending colon, 6 in the sigmoid colon, 17 in the rectum. For macroscopic type, 20 lesions were LST-NG 14 LST-G(mix), 4 lesions Is, and 1 IIa+IIc. In pit pattern diagnosis, 33 lesions were type VI, 6 type IV, and 3 type IIIs. By histological examination, 17 intramucosal cancers, 11 slightly submucosal cancers (SM-S), 6 SM-M cancers, and 6 high grade adenomas. All lesions were lateral free margins, and 2 lesions of 6 SM-M cancers were positive of vertical margins. 2 lesions of 6 SM-M cancers were performed as the palliative therapy. The median operation time was 90 minutes (range,30-270 minutes), and the en bloc resection rate was 95% (38/40). Of 7 noncurative resection, 6 SM-M cancers, and 1 SM-S cancer with lymphatic (or vessel) invasion (or poorly differentiated component). 5 patients who were noncurative underwent surgery for lymph-node dissection except for 2 palliative lesions. No lymph node metastasis and residual tumor in resected specimen. With regard to complications, postoperative bleeding were observed 5% (2/40). Both lesions were located in the rectum and controlled by endoscopic hemoclipping without surgery and blood transfusion. No perforation and penetration were found. Conclusion: On the basis of results of this study, ESD with Flush knife and CO2 insufflation for LST and large protruded lesions provided safe and successful outcome. This ESD procedure provided a high en bloc resection rate and a low rate of complication.

Endoscopic Mucosal Resection (EMR) for Large Sessile and Flat Colorectal Polyps: Technical Aspects and Outcome

Endoscopic Mucosal Resection (EMR) for Large Sessile and Flat Colorectal Polyps: Technical Aspects and Outcome

Advanced Colon Polypectomy

Advanced Colon Polypectomy

Incidence and predictors of “late” recurrences after endoscopic piecemeal resection of large sessile adenomas

Large sessile colorectal adenomas (>/=2 cm in size) resected piecemeal have a 0% to 55% rate of residual adenoma at the first follow-up. Guidelines recommend inspection of the polypectomy site 3 to 6 months after resection. Some patients with a negative examination at 3 to 6 months have a subsequent "late" recurrence. Our aim was to describe long-term follow-up of large sessile adenomas after piecemeal resection and to report the incidence and predictors of "late" recurrence. A retrospective study. A tertiary-referral center. Large sessile colorectal adenomas were identified through an endoscopic database. Polyps were resected by piecemeal technique; flat areas that could not be snared were treated with argon plasma coagulation. Patients who completed follow-up examinations at our center 3 to 6 months and at least 1 year after initial resection were included. "Late" adenoma recurrence. Of 136 polyps with complete follow-up, 24 (17.6%) had macroscopically evident residual adenoma at follow-up, including 18 at the first follow-up and 6 (4.4%) with a "late" recurrence. Among 94 polyps with no visible adenoma and with negative biopsy specimens of the scar at the first follow-up, 92 polyps (97.9%) were eradicated at late follow-up, compared with 36 of 42 (85.7%) of the remaining polyps (P = .005). A retrospective design. Our results confirm the phenomenon of "late" recurrences after endoscopic piecemeal resection of large sessile adenomas. However, a normal macroscopic appearance of the polypectomy site and negative scar biopsy specimens at the first follow-up is predictive of long-term eradication.