Endoscopic mucosal resection with a cap-fitted endoscope versus freehand gastric mucosectomy in an animal model

Feasibility of salvage endoscopic mucosal resection by using a cap for remnant rectal carcinoids after primary EMR

BACKGROUND

Secondary endoscopic treatment for remnant lesions of rectal carcinoid tumors after primary EMR or polypectomy is technically difficult because of fibrosis of residual tissues. EMR by using a cap (EMR-C), a method to resect the submucosal layer by suction by using a transparent cap, may be feasible as a salvage treatment.

OBJECTIVE

To assess the feasibility of salvage EMR-C.

DESIGN

Retrospective analysis.

SETTING

Tertiary academic health care system.

PATIENTS

Thirty-one patients who were referred for salvage treatment of a failed en bloc excision of rectal carcinoid tumors after primary EMR or polypectomy between January 2007 and December 2009.

INTERVENTIONS

Salvage EMR-C for remnant carcinoid tumors in the rectum.

MAIN OUTCOME MEASUREMENTS

Rate of complete resection, complications, length of procedure, and recurrence rate.

RESULTS

The mean age of the patients was 52.0±11.8 years (range 30-78 years). The mean tumor size was 8.9±3.2 mm (range 5.0-13.0 mm). The mean procedure time was 9.1±3.7 minutes, and clear resection margins were pathologically confirmed in all 31 patients. The most common complication of salvage EMR-C was bleeding (7 patients, 22.6%), which was successfully treated by hemoclipping in all cases. The 1-year follow-up colonoscopy and CT results for all patients were negative for recurrence.

LIMITATIONS

Retrospective design and limited cases at a single center.

CONCLUSIONS

EMR-C is a feasible salvage therapeutic option for failed en bloc excision after primary endoscopic treatment of rectal carcinoid tumors.

Endoscopic mucosal resection using a cap-fitted endoscope improves tissue resection and pathology interpretation: an animal study

BACKGROUND

Endoscopic mucosal resection using a cap-fitted endoscope (EMRC) has been proposed to be significantly better and safer for tissue resection compared with standard snare EMR. However, there are no valid animal or clinical data to support this. We aimed to compare EMRC with standard snare EMR in a porcine model with respect to tissue resected, ease of procedure, and degree of diathermic injury to the resected specimen.

METHODS

Gastric EMRs were randomly performed in pigs using a variety of techniques, including EMRC (1mm and 17-mm cap) and the standard snare technique, using a single-channel method without a grasping forceps. Geometric and histological assessment of the resection specimen for size, histological depth, and diathermic injury were performed by a single pathologist, blinded to the endoscopic techniques used.

RESULTS

Thirty-six gastric mucosal resections were randomly performed in three pigs. Use of EMRC resulted in a statistically significant greater resection specimen by weight, size, and histological depth compared with standard EMR (P < 0.04). Large-cap EMRC resulted in a statistically significant greater resection weight and size compared to small-cap EMRC (P < 0.05). There was a statistically significant greater degree of diathermic injury in the specimens resected using the standard snare EMR technique compared with EMRC (P < 0.006). There were no acute complications with either technique.

CONCLUSION

Gastric EMRC is more technically effective than and as safe and easy as standard snare EMR. Use of the cap, especially the larger cap, is associated with larger and deeper mucosal resection and less diathermic injury compared with the standard snare technique, making the pathologic assessment of depth and margin involvement more reliable. When possible, EMRC should be the EMR method of choice.

Endoscopic mucosal resection

Endoscopic mucosal resection (EMR) is a promising therapeutic option for removal of superficial carcinomas or premalignant lesions throughout the gastrointestinal tract. This review discusses indications and the several techniques of EMR in early tumors of esophagus, stomach, duodenum, and colon. EMR is not yet widely utilized in the West. However, great benefits may be obtained from this non-invasive technique after an accurate evaluation of patients and a careful staging of lesions that may assess the depth of infiltration and exclude the presence of lymph node metastases. EMR permits a complete removal of the lesion with histologic assessment of the entire specimen and the change in the pathologic stage in a significant number of patients. To minimize the risk of serious complications (mostly bleeding and perforation), only experienced endoscopists should undertake EMR in an appropriate environment. Data from literature are encouraging on the use of EMR, but a long-term follow-up of a large number of patients is necessary to confirm the effectiveness of this therapy.

Usefulness of EMR with an oblique aspiration mucosectomy device compared with strip biopsy in patients with superficial esophageal cancer

BACKGROUND

EMR is now widely accepted as a treatment option for superficial esophageal cancer. Endoscopic oblique aspiration mucosectomy with an oblique aspiration mucosectomy device was performed, and the results were compared retrospectively with those of conventional strip biopsy.

METHODS

Strip biopsy (April 1991 through October 1999) or endoscopic oblique aspiration mucosectomy (November 1999 through December 2002) was performed in a consecutive series of patients with superficial esophageal squamous-cell carcinoma. Variables assessed were size of resection specimens, rate of complete resection, and complications.

RESULTS

Of the consecutive series of 66 patients with superficial esophageal cancer, 27 underwent strip biopsy and 39 had endoscopic oblique aspiration mucosectomy. The two groups were similar with respect to age, gender, and lesion macroscopic appearance. The endoscopic oblique aspiration mucosectomy group had a significantly greater mean depth of tumor invasion and had significantly more large lesions vs. the strip biopsy group. The mean longest diameter of resection specimens was significantly greater with endoscopic oblique aspiration mucosectomy (23.9 [5.2] mm) than with strip biopsy (15.2 [4.9] mm) (p<0.001). The en bloc resection rate was 33.3% (9/27) in the strip biopsy group and 46.2% (18/39) in the endoscopic oblique aspiration mucosectomy group (p=0.322). Despite larger lesion size in the endoscopic oblique aspiration mucosectomy group, the complete resection rate was similar between the strip biopsy (70.4%) and endoscopic oblique aspiration mucosectomy (74.4%) groups (p=0.783). The complete resection rate for lesions 30 mm or greater in diameter was slightly but not significantly higher in the endoscopic oblique aspiration mucosectomy group (84.4%) compared with the strip biopsy group (70.4%) (p>0.999). With respect to complications, the rates of bleeding and submucosal hematoma were similar. Esophageal stenosis occurred after the procedure in 3 patients in the endoscopic oblique aspiration mucosectomy group. All were managed by endoscopic dilation, and symptoms improved.

CONCLUSIONS

Endoscopic oblique aspiration mucosectomy is safe and effective for the treatment of superficial esophageal cancer.

Circumferential endoscopic mucosal resection in the swine esophagus assisted by a cap attachment

BACKGROUND

The feasibility and safety of piecemeal, circumferential endoscopic mucosal resection of the distal esophagus are unknown. This study assessed this procedure in a porcine model.

METHODS

Different techniques of endoscopic mucosal resection were tested in Phase I of the study in two animals. During Phase II, 6 pigs underwent piecemeal cap-assisted EMR of the distal esophagus. The mucosa of one half of the circumference of the distal 5 cm of the esophagus was resected. After complete endoscopic re-epithelization, endoscopic mucosal resection was performed on the remaining unresected hemi-circumference. Healing was promoted by daily administration of lansoprazole and documented by weekly endoscopy.

OBSERVATIONS

In Phase I, one perforation occurred during initial testing of cap-assisted endoscopic mucosal resection. Subsequent cap-assisted endoscopic mucosal resection led to homogenous and uniform piecemeal resection of mucosa. In Phase II, circumferential cap-assisted endoscopic mucosal resection was performed in 6 pigs without perforation or major bleeding. Complete endoscopic re-epithelization occurred over a mean of 3.6 weeks (range: 3-5). Strictures developed in 3 animals.

CONCLUSIONS

Piecemeal circumferential cap-assisted endoscopic mucosal resection is safe and feasible in the normal swine esophagus. Proper technique for cap-assisted piecemeal endoscopic mucosal resection is necessary to minimize the risk of perforation. Procedural complications include esophageal stricture formation.

Interventional procedures

During the past year, numerous articles were published on interventional procedures of the stomach, focusing on upper gastrointestinal tract bleeding, gastric cancer, gastric outlet obstruction, and benign disease. In the area of upper gastrointestinal tract bleeding, early endoscopy is warranted for early therapeutic intervention and for triage. In patients with bleeding related to peptic ulcer disease, combination therapy (epinephrine injection in conjunction with electrocoagulation therapy) remains the standard of care. Hemoclipping is a new technique that may be helpful in cases in which conventional therapy fails. Repeat endoscopy should always be considered in patients in whom the first attempt at endoscopic therapy fails. In patients with bleeding related to portal hypertension, prophylactic antibiotics may decrease the risk of infections. Banding remains the therapy of choice for this group of patients. There is no documented benefit for combination therapy (banding and sclerotherapy). Transjugular intrahepatic portosystemic shunts may be helpful in the treatment of hypertensive portal gastropathy but not gastric vascular ectasias. In the area of gastric cancer, management revolves around staging. This can be accomplished best through the use of CT scan and endoscopic ultrasound. In patients with early limited disease, attempt at endoscopic mucosal resection should be considered. This technique can be performed in a variety of ways: the most common method seems to be through the use of a saline injection, to separate the mucosa-submucosal layer, followed by a cap-assisted snare resection with suction. The safety, efficacy, and outcome of this technique are reviewed. Gastric outlet obstruction remains a difficult problem to treat endoscopically. However, there is some evidence that endoscopic therapy may be successful in benign disease and should be considered prior to surgical intervention.