A successful single-step endoscopic resection of a 40 millimeter flat-elevated tumor in the rectum: endoscopic mucosal resection using sodium hyaluronate

Iatrogenic perforation associated with therapeutic colonoscopy: a multicenter study in Japan

BACKGROUND AND AIM

Colonic perforation is the serious accidental complication. The aim of this study is to analyze the clinical presentation and management of recent iatrogenic perforations during therapeutic colonoscopy.

METHODS

Consecutive patients referred to four academic cancer centers in Japan were retrospectively reviewed using each center's endoscopy database of medical records. Data was obtained by means of an extensive data collection sheet. Since we evaluated the data including iatrogenic perforation during newly developed therapeutic procedure such as endoscopic submucosal dissection (ESD) or hemoclips, the collection of patient data was set from the period of the beginning of ESD technique in each hospital in this study.

RESULTS

The overall rate of occurrence of perforation was 0.15% (23/15, 160). Perforation rate for EMR (0.58%) showed a significantly higher rate (P < 0.0001) than that for hot biopsy and polypectomy. The rate for ESD (14%) showed a markedly higher rate (P < 0.0001) than that for other standard procedures. Of those perforations, endoscopic clipping was performed in 56.5% of the patients, and conservative treatment was successful in 100% of the patients with successful closure. Both CT scan findings and serology results (WBC, CRP) after perforation were poor predictors for need for surgery as opposed to conservative management.

CONCLUSIONS

Further improvements in EMR with special knife techniques are required to simply and safely remove large colorectal neoplasms, because perforation rate for ESD shows a markedly higher. Conservative management may be possible in patients who have undergone complete endoscopic clipping.

Endoscopic removal of large sessile colorectal adenomas: is it safe and effective?

Large sessile colorectal polyps represent a treatment challenge. Nowadays there are discrepancies regarding how to proceed with them because of morbidity, the possibility of incomplete endoscopic resection, and the high possibility of a coexisting malignancy. This study was performed to determine the safety and effectiveness of endoscopic removal of sessile colorectal adenomas larger than 4 cm. Seventy-four patients with a total of 74 sessile polyps larger than 4 cm in diameter were treated endoscopically. Polyps were removed using argon plasma coagulation (APC) as an adjunct to piecemeal technique. Surgery was recommended in patients with invasive neoplasia. Patients with favorable histology (low-grade dysplasia [LDG] or high-grade dysplasia [HGD]) were followed up with monthly endoscopies untill total ablation of the lesion, and then at 3- to 6-month intervals. LGD was found in 38 patients, HGD in 24, and invasive neoplasia in the remaining 12 patients. A total of 54 patients were followed up for at least 6 months. Recurrence rate of polyps with favorable histology was 9.2% (5/54). Postpolypectomy bleeding was the only complication, observed in 10 patients (13.5%). We conclude that piecemeal polypectomy plus APC without saline injection, performed by an expert endoscopist, is a safe and effective treatment for all LGD or HGD large sessile colorectal polyps.

Selective fluid cushion in the submucosal layer by water jet: advantage for endoscopic mucosal resection

BACKGROUND/AIM

Numerous new techniques have recently been reported and described for the endoscopic mucosal resection of large superficial lesions of the gastrointestinal tract. We present here for the first time the application of a water jet dissector for mucosa elevation.

MATERIALS AND METHODS

In an ex vivo study, the effectiveness of a water jet dissector (Helix Hydro-Jet) placed directly on the stomach walls of 8 pigs was examined to create a mucosal elevation. After having determined optimal pressures, angle of application, and application times, 13 submucosal fluid cushions were produced in different areas of the stomach walls of 8 pigs in vivo, and the sizes of the resulting submucosal cushions were measured.

RESULTS

Using pressures between 30 and 70 bar, it was routinely possible to create submucosal fluid cushions in the stomach wall ex vivo as well as in vivo. Histological examination showed a selective edema in the submucosa without damage to the deeper mucosal layers of the gastric wall.

CONCLUSIONS

The capacity of a targeted high-pressure water jet to penetrate the mucosa and selectively create a fluid cushion in the submucosa facilitates endoscopic resection of the mucosa. This new method could contribute to ameliorate the endoscopic treatment of mucosal tumors which previously could not be resected endoscopically due to their size, extent, or location.

Novel endoscopic therapies for gastrointestinal malignancies: endoscopic mucosal resection and endoscopic ablation

Gastrointestinal malignancies are often detected at advanced stages when the prognosis is poor. Screening guidelines that vary accord-ing to the regional disease prevalence are needed. High-resolution endoscopy, magnification endoscopy, chromoendoscopy, light autofluorescence endoscopy, and optical coherence tomography are new technologies designed to improve endoscopic detection. Once detected, lesions must be accurately staged, including depth of mucosal penetration and lymph node involvement, to determine endoscopic resectability. Widely applicable, relatively safe, and minimally invasive alternatives to surgery are needed. Endoscopic mucosal resection and endoscopic ablation are potentially curative for malignancies limited to the mucosa, obviating the need for surgery in these patients.

Hyaluronic acid stimulates tumor-cell proliferation at wound sites

BACKGROUND

For EMR, the submucosal injection of sodium hyaluronate has become popular, because this substance creates a more prominent and longer-lasting mucosal protrusion than normal saline solution. However, the effects of sodium hyaluronate on tumor growth at wound sites remain unclear.

METHODS

For these experiments, a murine model with artificial wounds was used. Forty mice were randomly divided into two groups according to the substance to be injected into a wound: a sodium hyaluronate group and a control group. Tumors were created by inoculation of transplantable adenocarcinoma cell line colon 26. Two weeks later, the size, weight, proliferating cell nuclear antigen-labeling index, and CD44 expression of the subcutaneous tumors were compared between the two groups of mice.

RESULTS

There were significantly greater increases in the growth and the weight of subcutaneous tumors in the sodium hyaluronate group compared with the control group. The PCNA-labeling index of cancer cells also was higher in the sodium hyaluronate group. Immunohistochemistry and Western blot analysis demonstrated that the CD44 protein expression of cancer cells was higher in the sodium hyaluronate group vs. the control group.

CONCLUSIONS

In this study, sodium hyaluronate enhanced both tumor growth and CD44 expression of cancer cells at wound sites, suggesting that the use of sodium hyaluronate for EMR might stimulate the growth of residual tumor cells.

Endoscopic closure of mucosal defects with metallic clips after endoscopic mucosal resection in patients with intramural tumors of the stomach: A retrospective study

Background:  Representative complications of endoscopic mucosal resection to treat intramural gastric tumors include bleeding and perforation. The purpose of the present study was to clarify whether endoscopic closure of mucosal defects using metallic clips decreases the incidence of delayed bleeding following endoscopic mucosal resection.

Patients and Methods:  The records of 187 intramural tumors of the stomach in the 181 patients that were treated by endoscopic mucosal resection between 1992 and 2001 were reviewed retrospectively. The patients were classified into two groups. The first group included patients who received endoscopic mucosal resection but were not treated by endoscopic mucosal closure. The second group included patients who were treated with endoscopic mucosal closure using metallic clips after endoscopic mucosal resection. The incidences of delayed bleeding following endoscopic mucosal resection in these two groups were evaluated.

Results:  Delayed bleeding following endoscopic mucosal resection was observed in 13 of 96 (13.5%) of the lesions of the first group. Delayed bleeding was encountered in only two of 91 (2.2%) lesions of the second group.

Conclusions:  Endoscopic closure of mucosal defects with metallic clips after endoscopic mucosal resection in gastric lesions was useful in decreasing the incidence of delayed bleeding following endoscopic mucosal resection.

Experience in the endoscopic management of large colonic polyps

BACKGROUND

Large colonic polyps present a particular challenge to endoscopists because of the risks of significant haemorrhage, perforation, inadequate polypectomy, or trying to snare an unrecognized cancer. The alternative to endoscopic therapy of large polyps is surgical resection and although minimally invasive techniques are available, risks are significant. Although neither surgery nor endoscopy is a perfect way of treating large colonic polyps, endoscopic resection is usually tried first. Most series of endoscopic polypectomies are small, include both rectal and colonic polyps and have varying size and shape criteria. The purpose of the present study is to describe a large consecutive series of colonic polyps evaluated endoscopically, to determine the chances of performing a safe, effective endoscopic polypectomy.

METHODS

All colonic polyps>20 mm in maximum dimension assessed during colonoscopy from 1989 to 2002 were reviewed. Rectal polyps were excluded. Demographic data for the patients were abstracted, as were data regarding the outcomes of polyp assessment and treatment. Primary end-points were: the need for surgical resection, the incidence of postpolypectomy complications and the persistence of the index polyp at follow up. Independent variables included the endoscopically assessed size of the polyps, the year in which the polypectomy took place, the shape of the polyps and their location within the colon.

RESULTS

During the period under review 311 large polyps were removed from 252 different patients. Of these, 263 polyps were removed endoscopically and 48 polyps were removed surgically. An additional 18 endoscopically removed polyps ultimately needed surgery for recurrence or malignancy. There were no deaths but 19 complications of endoscopic polypectomy (17 late haemorrhage and two postpolypectomy syndrome). At first follow up, 22% of polyps had persisted, this decreased to 14% at second follow up and 7% at third. Complications were more common in right sided polyps and in flat or sessile lesions. Pedunculated polyps never persisted or recurred and had the lowest rate of surgery. Larger polyps had higher rates of advanced histology, complications, polyp persistence and the need for surgery.

CONCLUSIONS

Polyp size, location and shape influence the results of endoscopic resection of large colonic polyps. Polyps>30 mm in maximum diameter are significantly more advanced histologically but also significantly more difficult to treat successfully than those <30 mm. However, size alone is rarely a contraindication to endoscopic resection.

A new method of EMR: submucosal injection of a fibrinogen mixture

BACKGROUND

The technical limitation associated with submucosal injection of normal saline solution during EMR is the relatively short duration of mucosal elevation. The clinical application of a new method of EMR with submucosal injection of a fibrinogen mixture was evaluated.

METHODS

Thirty-five early stage neoplastic gastric lesions were resected by EMR with submucosal injection of a fibrinogen mixture. The efficacy and clinical outcomes were analyzed.

RESULTS

Additional submucosal injection was not required for any of the 35 lesions to complete the EMR with submucosal injection of a fibrinogen mixture procedure. The rates of en bloc resection and complete resection were, respectively, 82.9% and 88.6%. The en bloc resection rate was significantly lower for lesions over 20 mm in diameter (60% vs. 92%; p<0.05) and for lesions on the lesser curvature or posterior wall of the stomach compared with those on the greater curvature or anterior wall (55.6% vs. 92.3%; p<0.05). The rate of complete resection also was dependent on the size and location of the lesions. There was no major EMR with submucosal injection of a fibrinogen mixture related complication including bleeding or perforation.

CONCLUSIONS

EMR with submucosal injection of a fibrinogen mixture is an easy, safe, and technically efficient method for complete EMR.

Pitfalls of endoscopic ultrasound staging after application of electrocautery

Patients may be referred for endosonography after endoscopic resection of polyps because of cancer identified in the histologic specimen. To assess the effects of electrocautery-induced tissue changes on tumor staging by endosonography, endosonography findings after endoscopic removal of large polyps were correlated with surgical and endoscopic pathology. Endosonography findings revealed irregular and thickened wall layers, especially in the muscularis propria with pseudopod extensions. Five of 7 patients had evidence of cancer in the endoscopic specimen. However, no residual tumor was found in the surgically resected bowel (2 patients) or in subsequent biopsies of the endoscopic resection site (3 patients). In 2 other patients, no cancer was present in the endoscopic specimen, and follow-up biopsies of the endoscopic resection site were all benign. Electrocautery-induced inflammatory changes create hypoechoic changes within the gut wall that may mimic tumor invasion. Irregularities in the muscularis propria layer cannot be relied upon to diagnose a T2 or T3 lesion by endosonography in this setting. Patients with large polyps greater than 2 cm and other mucosal lesions with malignant potential should undergo endosonography prior to endoscopic resection.

Hydroxypropyl methylcellulose: A better submucosal fluid cushion for endoscopic mucosal resection

BACKGROUND

Formation of a submucosal fluid cushion has become integral to endoscopic mucosal and polyp resection. Solutions available for injection into the submucosa of the GI tract create short-lasting submucosal fluid cushions or are costly. The feasibility, durability, and histologic response to submucosal fluid cushions created by injection of hydroxypropyl methylcellulose were studied in the esophagus of pigs.

METHODS

Thirty-six esophageal submucosal fluid cushions created with hydroxypropyl methylcellulose were studied in 12 animals divided in 2 groups of 6 animals each. In Group I, 18 submucosal fluid cushions were created by submucosal injection of hydroxypropyl methylcellulose followed by tattooing. In Group II, 18 submucosal fluid cushions were created by submucosal injection of hydroxypropyl methylcellulose, with sites marked by an endoscopically placed suture. In all cases, the duration of the submucosal fluid cushion was measured. After 7 days, submucosal fluid cushion sites were assessed by EGD, necropsy, and histologic evaluation.

RESULTS

The mean submucosal fluid cushion duration was 36 minutes (3-45 minutes) and 38 minutes (5-45 minutes) for, respectively, Groups I and II. EGD and necropsy after 1 week showed normal-appearing mucosa at the site of all submucosal fluid cushions in both groups. Some Group I animals additionally had nodules at the tattoo sites. Histologic assessment demonstrated minimal alterations in 33 of 36 (92%) submucosal fluid cushion sites and localized mild inflammatory reaction in 3 of 36 (8%). In Group I, 8 of 18 (44%) tattoo sites exhibited a significant inflammatory reaction, including 3 abscesses.

CONCLUSIONS

Hydroxypropyl methylcellulose creates a long-lasting submucosal fluid cushion with minimal tissue reaction and should be considered a low-cost option for creating submucosal fluid cushions. The use of tattooing with carbon black should be carefully considered when histologic study is required to assess potential inflammatory tissue responses to an invasive technique or instillation of foreign material in the GI tract.

Success rate of curative endoscopic mucosal resection with circumferential mucosal incision assisted by submucosal injection of sodium hyaluronate

BACKGROUND

Circumferential mucosal incision around a lesion is effective for reliable endoscopic mucosal resection. However, mucosal incision with a needle knife is difficult, even with submucosal injection of normal saline solution. To make needle-knife incision easier and safer, sodium hyaluronate has been used rather than normal saline solution. The aim of this study was to evaluate the clinical outcome of endoscopic mucosal resection with circumferential mucosal incision assisted by submucosal injection of sodium hyaluronate.

METHODS

For 70 gastric lesions treated by submucosal injection of sodium hyaluronate, the size of the lesion and the resection specimen, the en bloc resection rate, complications, and local recurrence during follow-up were assessed.

RESULTS

The mean size of the lesions and resection specimens were, respectively, 19.9 mm and 30.0 mm. The en bloc resection rates were 89% (42/47) for lesions up to 20 mm in diameter and 48% (11/23) for those greater than 20 mm (1-20 mm vs. >20 mm, p = 0.0004). Three patients underwent surgery because of invasive cancer in the EMR specimen. During follow-up (median 14 months, range 3-38 months), 2 recurrent lesions were found. No major complication occurred.

CONCLUSIONS

Submucosal injection of sodium hyaluronate is a reliable method with a high success rate for en bloc resection of lesions up to 20 mm in diameter. Mucosal incision with a needle knife can be performed safely with submucosal injection of sodium hyaluronate.

Endoscopic resection of large sessile colonic polyps by specialist and non-specialist endoscopists

BACKGROUND

Patients with large sessile colonic polyps for which endoscopic resection might be feasible are often referred directly for operation. The aim of this study was to determine the outcome of patients with such polyps diagnosed by specialist and non-specialist colonoscopists.

METHODS

Patients with large (greater than 2 cm) sessile polyps detected at colonoscopy from January 1995 to July 2000 were identified. Resection technique and clinical and endoscopic outcomes were recorded. Two of the colonoscopists (B.P.S., C.B.W.) are recognized as specialists.

RESULTS

Some 130 polyps were identified, 100 detected by either of two specialist endoscopists (including 14 cancers) and 30 by 14 non-specialist endoscopists (including ten cancers). Endoscopic resection of benign polyps was attempted by experts in 80 (93 per cent) of 86 cases and by non-experts in 15 of 20 cases (P = 0.03), with successful management by endoscopy alone in 61 (76 per cent) of 80 and in six of 15 cases respectively (P = 0.01). Complications occurred following three polypectomies performed by an expert (bleeding, two; pain, one) and one by a non-expert (bleeding). The estimated end-cost of management by specialists was less than half of that by non-specialists.

CONCLUSION

Endoscopic resection of large sessile colonic polyps is feasible in the majority of patients and should be considered as first-line therapy. Prompt referral to a specialist endoscopist may improve outcomes by avoiding operation or enabling complete excision at a single endoscopy session.

Treatment with argon plasma coagulation reduces recurrence after piecemeal resection of large sessile colonic polyps: a randomized trial and recommendations

BACKGROUND

Recurrence is frequent after piecemeal snare resection of large sessile colorectal polyps. The aim of this study was to evaluate the safety and efficacy of argon plasma coagulation (APC) in preventing recurrence when applied to the edge and base of the polypectomy site after apparently complete piecemeal resection.

METHODS

Patients with large (>1.5 cm) sessile polyps removed by piecemeal snare cautery were placed into 2 groups. The first consisted of patients with polyps believed by the endoscopist to be completely excised. These patients were randomized to either no further therapy (control) or to APC of the rim and any residual mucosal or submucosal tissue in the base of the polypectomy site. The second group comprised patients in whom polyps, as judged by the endoscopist, were incompletely excised by snare polypectomy; APC was routinely applied without randomization to all visible remaining adenomatous tissue. Follow-up colonoscopy was performed within 3 months and 1 year; biopsy specimens were taken routinely from the resection site and further polypectomy was performed as indicated.

RESULTS

There were fewer recurrences after APC in the randomized group (1/10 APC, 7/11 no APC; p = 0.02). In the group with initial incomplete snare polypectomy, recurrence was detected at 3 months in 6 of 13 despite APC. One patient was hospitalized with abdominal pain and minor rectal bleeding but required no intervention. There were no other episodes of significant late bleeding caused by piecemeal polypectomy. One patient was referred for surgery after unsuccessful endoscopic management.

CONCLUSIONS

In patients with apparent complete endoscopic snare resection of large adenomas, postpolypectomy application of APC reduces adenomatous recurrence.

Successful en bloc resection of a large superficial gastric cancer by using sodium hyaluronate and electrocautery incision forceps

BACKGROUND

The advisability of endoscopic mucosal resection (EMR) for treatment of large superficial gastric cancers has been challenged. For more reliable en bloc resection, a new method of EMR was developed that uses a viscous substance, sodium hyaluronate, and two newly designed devices.

METHODS

A large superficial gastric cancer was treated with this new EMR technique. Sodium hyaluronate was injected into the submucosa and mucosal incisions were made with a needle-knife. The newly developed incision forceps and flat-ended transparent hood were used for submucosal incisions.

RESULTS

The large cancer was successfully resected endoscopically as a single piece of mucosa 6 cm in diameter without complication. Histopathologic evaluation of the specimen confirmed that the resection was curative.

CONCLUSIONS

EMR with sodium hyaluronate along with two new devices may be a reliable method for en bloc resection of large superficial gastric lesions.

Endoscopic mucosal resection. Current concepts

Recent advances in endoscopic mucosal resection of superficial early digestive tract cancers are truly remarkable. The extraordinary long-term outcomes of patients who have been treated with endoscopic mucosal resection have encouraged the widespread practice of endoscopic mucosal resection in Japan. These minimally invasive techniques allow safe and effective treatment of diseases that would otherwise require major surgery. This article provides an overview of endoscopic mucosal resection techniques, their associated outcomes, and other potential applications of endoscopic mucosal resection.