Training and assessment

Ideally endoscopists learning EMR should go through a formal training period composed of observation and assisting procedures, prior to performing the technique under direct observation, and finally independent practice. There is no formal programme such as this available in the UK. Mentorship is the training method that was used in Gateshead. An accredited Bowel Cancer Screening Programme (BCSP) colonoscopist from a nearby Institution, with level 4 polypectomy competency acted as mentor, and provided specific support, hands on guidance and assessment throughout the early period of training. This approach facilitated development of new skill within Gateshead, avoiding the need to refer patients to other hospitals for polypectomy. Level 3 and 4 polypectomies were done jointly, and formative assessments for specific polypectomy procedures were undertaken.

New procedure committee and business case proposal

EMR polypectomy was formally approved by the hospital New Procedure Committee. A business case was presented to the endoscopy managers for fortnightly therapeutic lists of two EMRs per list. Business managers and the Institution were therefore aware of the development of the service from the outset, specifically the need to reduce patient numbers on these lists to allow adequate time for the procedure, and the risks and benefits of the procedure.

Quality assurance and MDT feedback

Continual prospective audit of patient outcomes was undertaken, with annual presentation to the lower gastrointestinal (GI) MDT. The endoscopist provided a regular presence at the lower GI MDT, from where many of the new referrals came.

Polyp referrals

On referral receipt following discussion at the MDT or following referral from an endoscopist, a letter was dictated to patients explaining the EMR procedure, the risks involved, specifically the risk of perforation, and the alternative options including surgery. The letter was copied to the endoscopy unit and an appropriate duration of time allocated on an endoscopy list. The letter was also routinely copied to the referring endoscopist, and the consent process presented and discussed annually at the colorectal MDT. The need for timely referral to the EMR service from diagnostic endoscopy or CT scan was reinforced to prevent undue delay in consent letters being sent to patients.

The procedures outlined in this manuscript were those performed between 1 January 2008 and 31 December 2011 after referral by a medical or surgical endoscopist as part of the new EMR service. Lesions are also reported that were identified by the EMR endoscopist on a routine diagnostic list, and subsequently brought back for an EMR procedure after appropriate consent.

Referrals

Table 1 outlines the patients undergoing EMR from service establishment through the next 4 years. There was an approximate four-fold increase seen in patients receiving this procedure as part of the EMR service. Some patients had more than one polyp requiring EMR. The mean time from sending a consent letter to patients, and performing the index EMR procedure remained similar across all year groups at between 4–5 weeks.

Polyp size

During the early stages of the EMR service, the majority of polyps were small, over 50% less than 20 mm, and only a third over 30 mm. As the service developed the proportion of larger polyps increased, such that by 2011 almost 85% of polyps were over 20 mm, of which more than two thirds were over 30 mm in size.

Figure 1 demonstrates the absolute numbers of polyps removed per year according to polyp size, revealing a clear year on year increase in the number of larger polyps removed, particularly those 30 mm or more.

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Figure 1

Number of endoscopic mucosal resections performed per year, stratified according to polyp size.

Histology

From 2009 onwards, there was a clear increase in polyps confirmed as either adenomatous or malignant after removal. Overall this histology accounted for between approximately 90% and 96% of polyp diagnoses. Polyps not identified as adenomatous or malignant were found to be inflammatory, hyperplastic or metaplastic.

Both the cancers identified in 2008 and 2009 showed invasion up to the resection margins. However, the four cancers removed by EMR in 2010 and 2011 were completely cleared with no evidence of local invasion, lymphadenopathy or metastasis on colonic resection or subsequent imaging. None of the attempted or removed polyps were known to be cancers prior to EMR, all were thought to be adenomatous.

Recurrence

In the EMR service, recurrence is assessed endoscopically at 3 months following index EMR in those patients identified as having adenomas. Photos are routinely taken of the polypectomy scar to prove clearance. If any residual islands of adenoma are seen, these are biopsied, and either raised and snared if possible, or destroyed with Argon Plasma Coagulation. Reasons for not performing EMR at 3 months include the finding of non-adenomatous histology or malignancy at index EMR, intercurrent co-morbidity making EMR higher risk, or patient preference not to undergo a repeat procedure.

As demonstrated in table 1, in 2008, the adenoma recurrence at 3 months was 75% (n=6/8), however this subsequently fell to 46.7% (n=7/15) in 2009, 22.22% (n=8/36) in 2010, and 4.76% (n=1/21) in 2011. Statistics for 2010 and 2011 are therefore comparable with other published series, which describe a recurrence rate of between 1.7–28% at follow up examination.8–12

Complications

The hospital Patient Administration System was interrogated to identify the 30-day re-admission rate following EMR, and notes were reviewed to establish the cause of re-admission. Complications were characterised as immediate peri-procedural bleeding that required therapy (eg, endoclips or adrenaline), delayed bleeding leading to re-admission, post-polypectomy syndrome leading to re-admission, perforation, and death. A summary of complications is presented in table 2.

In 2008 there was one immediate bleed following a 25 mm polyp removal, controlled with adrenaline injection and endoclips. The patient was admitted for 3 days observation then discharged. The day following discharge the patient experienced a cardiac arrest and died. Post mortem examination identified a perforation at the polypectomy site. A root cause analysis investigation performed concluded that the death was related to the polypectomy, with a delayed perforation.

In 2009 there was one delayed bleed 7 days following removal of a 40 mm rectal polyp. This required re-admission and was managed successfully with adrenaline, injection and endoclips.

In 2010 there were two peri-procedural bleeds after a 20 mm and 40 mm polypectomy respectively, both responded to endoscopic therapy without further need for intervention. Both were admitted overnight for observation. One received adrenaline and endoclips, the other adrenaline and heater probe therapy. There were three delayed bleeds, two of which were in patients with polyps greater than 30 mm. One patient was admitted, re-endoscoped and treated successfully with adrenaline and heater probe therapy. The other two patients were admitted for observation, but no intervention was necessary. One patient was admitted the same day as the EMR with severe abdominal pain and peritonism. A CT scan showed no evidence of perforation, they were commenced on intravenous antibiotics and the pain settled. The patient was discharged 48 h later with a presumed diagnosis of post polypectomy syndrome.

There was only one complication in 2011. This was a delayed bleed, requiring a two unit blood transfusion but no endoscopic therapy.

Overall bleeding rates requiring admission are comparable with published series, which describe a risk of between 2.9% and 16%.5 ,8–11 ,13

The overall perforation rate for the 4 years was 0.8% (1 in 120 polypectomies).

Polyps not attempted or not completed

In addition to the EMRs outlined in table 1, each year, there were a small number of patients in which the procedure was either not attempted or not completed.

There were three cases overall where after consideration of the risks and benefits of the procedure, the patients decided not to proceed to EMR (two in 2010, one in 2011). In all cases the patient also declined surgery.

In three cases the endoscopist decided not to attempt EMR (two in 2010, one in 2011). In two of these, therapeutic endoscopy was not attempted due to an adverse risk:benefit ratio as a consequence of significant co-morbidity (advanced liver disease and dementia respectively). The other procedure was not attempted, as at endoscopy the lesion was complex and extensively involved the caecum and ileo-caecal valve. The patient in this circumstance was referred on for surgery.

Over the 4 years there were a total of nine incomplete polypectomies, where the endoscopist was technically unable to clear all the polyp tissue at EMR (two in each of 2008–2010, three in 2011). Five were due to non-lifting of the polyp on injection, precluding successful snare, and in the remaining four patients complete removal was unsuccessful after prolonged de-bulking. In total six of these nine polyps were found to be malignant. Five were primary colonic cancers, and one a metastatic deposit from an ovarian primary.

Reduction in surgical resection rates

An audit of surgery for benign colonic lesions analysed all resection specimens in 2005 and 2010. Six resections for adenomatous colorectal lesions were performed in 2005. None had attempted EMR and lesions varied from one that would have been technically challenging (a carpet like lesion in the caecum, 80×65 mm measured at resection) and five lesions that would now be routinely attempted endoscopically (25 mm sessile caecal, 45 mm sessile rectal, 65 mm pedunculated sigmoid, 20 mm sessile rectal, 20 mm sessile caecal polyps respectively). In 2010 there were three resections for adenomatous colorectal lesions. One was technically challenging covering the caecum and ileocaecal valve and referred for surgery (after EMR assessment) as described above. One was not referred to the EMR service (60 mm pedunculated ascending) and the other was assessed as not removable by one of the other gastroenterologists as it did not rise with injection.