What is Endocuff Vision?

A polypropylene device which is mounted onto the end of the colonoscope. 

 

NICE published guidance on use of an Endocuff, to improve adenoma detection rate during colonoscopy. 

 

What’s the evidence for it’s use?

The ADENOMA trial showed global improved adenoma detection rate (ADR) and mean adenomas per colonoscopy with the Endocuff vision. These benefits in detection were mainly due to improvements in the bowel cancer screening program (BCSP) population[12].

The study recruited 1772 patients, half were randomised to standard colonoscopy, and half to Endocuff vision assisted colonoscopy. The Endocuff vision group had ADR (40.9% vs. 36.2%, p=0.02) and mean number of adenomas (95 per 100 procedures vs 75 per 100 procedures, p=0.02).

The global increase was mostly due to a 10.8% higher ADR in the BCSP subgroup using Endocuff vs standard colonoscopy (61.7% vs 50.9%, p=0.001). A statistically significant higher detection was not seen in the non-BCSP sub-groups for ADR, mean adenomas per procedure or polyp detection rate.

When should I use the Endocuff?

The ADENOMA trial suggests improved visualisation and ADR in populations where neoplastic pathology is more common, therefore BCSP and patients attending for polyp surveillance.

When should I not use the Endocuff?

The ADENOMA study excluded over half the patients they invited to participate (3928 patients invited, 2156 patients excluded, 1772 patients recruited), therefore Endocuff is not for everyone. ADENOMA did not recommend Endocuff in patients with:

• Suspicion of bowel obstruction
• Colon cancer
• Polyposis syndromes
• Colonic strictures
• Severe diverticulosis
• Active colitis
• Current anticoagulation
• Pregnancy
• Attending for therapeutic assessment of known lesion.

In the ADENOMA trial the Endocuff needed to be removed and the colonoscopy restated in 4.1% of cases, due to detected of:

• Acute angulation in a fixed sigmoid, as this rendered scope insertion more difficult,
• New diagnosis of polyposis syndrome
• New active colitis
• New stricture

Why does Endocuff improve detection?

The higher increase in detection of adenomas was in the left colon, where colonic folds are most prominent. The authors considered that holding back of mucosal folds improves visualisation and stabilises colonoscope position to prevent slipping back and avoiding rapid sliding.

Will Endocuff slow me down?

Unlikely, as there was no significant difference in caecal intubation rates or insertion times between arms. 

What’s the minimum number of colonoscopies to maintain competence?

JAG and the BSG recommend a minimum of 100 procedures a year to maintain competence[13]. A recent systematic review demonstrated that number of procedures was associated with better caecal intubation rates and a trend to lower adverse events post-colonoscopy[14]. Evidence for improving polyp detection with increasing numbers is lacking. Although few studies have looked at endoscopists performing <100 procedures a year. Forbes et al. suggests "task repetition" may not improve "perceptive skills" reliant on concentration[14].

It’s difficult to get minimum numbers with mixed clinical jobs

In our interviews prior to the NED APRIQOT study, endoscopists recognised the relationship between number of procedures and colonoscopy quality, but commonly encountered barriers to achieving the minimum number these included clinical on-calls and acute weeks for medical endoscopists, leave and training other endoscopists.

“There’s always a pull between theatre, your clinical commitments and service users and endoscopy and I think it’s very difficult … It’s just getting the continuity and the thing about scoping is, it’s keeping it up … you have to do it very, very regularly to keep that up because you lose it quite quickly.”
(Consultant surgeon)

“You need to do about 120 per year to keep your hand in really … I’m guessing a lot of units around the country, certainly here, we’re getting a lot of pull for our medics to do more general medicine and out surgeons to do more surgery and therefore there is not the number of sessions to get endoscopy unless they make a real effort to jiggle their timetable.”
(Consultant gastroenterologist)

Speaking to clinical leaders about accessing colonoscopy can help

Our endoscopists described using the report that showed low numbers of procedures to access more endoscopy lists. Strategies described included taking on extra endoscopy lists, increasing the number of colonoscopies on endoscopy lists and negotiating more endoscopy time in job plans after discussion with clinical leaders.

“There is scope for increasing the number of lists … [with] waiting list initiatives, I’m sure that’s the same with so many trusts at the moment.”
(Consultant surgeon)

“I usually have double-enders, OGDs, colons and the majority are colonoscopies, I try to ask to get mostly colonoscopies, to keep my numbers up, to keep them as near to 100 a year as I possibly can. I struggle … I think that’s one thing I’m going to have to put into my job plan review, this year, to try and get some more endoscopy lists, to keep my numbers up.” (Consultant surgeon)

“This is something you want to focus on, therefore you should be doing more to allow you to progress. … It [the report] allows me the leverage to go and say, “Actually I need to change my job plan because this is something I want to do” … use it as leverage when you go to the clinical director for your job planning.”
(Consultant gastroenterologist)

There’s an upper limit too

Our participants perceived an upper limit of procedures too, as high numbers of procedures could cause detection fatigue and ergonomic problems (see our tips on colonoscopy ergonomics and staying comfortable). The upper limit is likely to be above what most endoscopists perform but may be more relevant those whose job-plan is endoscopy predominant. Anecdotal reports suggest that issues may arise when more than 4 or 5 lists a week are performed, although this will vary between individuals. Our participants described having a variety of procedures on a long list could help and using the nursing team for prompts.

“I think generally I need … not to be entertained but I need variety and so I think it would become very monotonous if I was just doing colonoscopy after colonoscopy after colonoscopy. I think maybe then I would find it more difficult to try and keep looking because you almost feel like you have been there before.”
(Consultant gastroenterologist)

“You get stuck in the moment … when it’s the last patient on your list of six and … they kind of like merge into one and you’re like, ‘Oh, right clopidogrel, oh yes, okay’. So, yes, [the nursing team] are pretty good at doing [cues].”
(Clinical endoscopist)

“Occasionally your concentration drifts, especially at the end of a list. So yeah, I ask [the nursing team] to just have a look … and if they do see anything, shout up”.
(Clinical endoscopist)

So, if you aren’t reaching 100 procedures, speak to your unit lead.
If you feel you are doing too much, think about variety on your lists and using nursing prompts to keep your detection eye in.

Post-colonoscopy colorectal cancer (PCCRC)

Last year Anderson et al. analysed 7 years of PCCRC data for their trust, undertaking a root cause analysis of 107 cases[15].

 

PCCRC cases are colorectal cancer cases diagnosed 6 – 36 months after colonoscopy, so potentially missed on index colonoscopy (i.e. false negative colonoscopies). True positives are where colorectal cancer is diagnosed within 6 months[15].

PCCRC rate = False negatives / (True positives + False negatives)

They found just under 50% of cases originated in the proximal colon, similar to previous data from an American cohort[16]. They also saw 27% of cases originating in the rectum (Figure).

This emphasises the importance or reintubating the proximal colon, and careful rectal inspection and retroflexion. In these patients rectal retroflexion was performed in just 15%, the authors suggest rectal retroflexion will not prevent all rectal PCCRC but is a proxy for adequate visualisation of the rectum. The BSG recommend digital examination in 100% of cases and rectal retroflexion in at least 90% of cases[13].

Regarding polyp detection, early studies in screening flexible sigmoidoscopy show an increase in adenoma detection rate of around 1% with rectal retroflexion[17]. However, later observational studies only found a non-significant improvement in polyp detection rate of 0.5% with rectal retroflexion, compared to careful forward viewing[18].

 

What are the risks of rectal retroversion?

There is a small risk of perforation in the rectum, one large case series reported this as 4 cases in 40 000 consecutive colonoscopies, or 0.01%[19]. To avoid this, first examine the rectum carefully in forward view to the dentate line, and assess the luminal calibre. In around 5% of cases, if the rectum is narrow, and the distal rectal walls are visible circumferentially, then after photo-documentation retroflexion may not be warranted. Avoid turning the bending section during retroflexion or advancing the scope against resistance[18,20].

Figure: Location of PCCRC n=107 (extract Anderson 2020)

How do I perform retroflexion?

Rex et al. describe the technique of retroflexion as: “The retroflexion technique is to advance most of the bending section into the rectum, deflect the instrument maximally in the up direction (or both up and left), grasp the insertion tube with the palm facing up, and advance the insertion tube forward while rotating counter-clockwise. An effective retroflexion visualises the proximal anal canal and the distal 3–4 cm of rectal mucosa. The instrument is rotated to see the full circumference of the distal rectum.”[20]

Re-intubate the right colon for a second forward view.

Desai et al describe that right sided lesions are often missed in the standard colonoscopy, with higher adenoma miss rates compared to the left colon[21]. The authors undertook a systematic literature review of studies looking at a second forward view and retroflexion in the caecum. Using a pooled analysis of 2988 patients second forward view of the right side of the colon increase right side adenoma detection rate (ADR) for 10% versus retroflexion which increased right sided ADR by 6%.

Right-sided lesions tend to be flatter than left-sided lesions hence are more difficult to identify. They also can be hidden on the proximal sides of folds and flexures.

We recommend a second forward view over retroflexion, because, as the study highlights, retroflexion in the caecum can be challenging, particularly in patients with previous abdominal surgeries and significant looping. Retroflexion has a reported rate of adverse events of 0.03%, and is best performed with a paediatric colonoscope. In contrast a second forward view examination is safe, easy to perform without the need to learn a new technique, and can be done with any type of colonoscope.

How important is this?

Moving the patient during colonoscopy withdrawal facilitates distension of different colonic segments, as gas rises to the least dependent areas. Multiple RCTs demonstrate significantly improved Adenoma Detection Rate and Polyp Detection Rate with dynamic position changes[22–25]. This is most significant in the right colon using the left lateral position, in one trial increasing proximal polyp detection from 17.7% to 26.2% (p=0.01)[22].

When should I turn the patient?

Position change is frequently used in caecal intubation and should be used on withdrawal to allow maximal colonic distension. The basic principle is to use gravity to ensure the colonic segment being examined is at the highest point to optimise insufflation. The South West Endoscopy Training Academy developed the “Colon Map” for training which provides detailed instructions on position changes and techniques for intubation and visualisation. In simple terms, the optimal positions for visualisation are:

• Caecum to hepatic flexure: Left lateral (caecum may require different positioning depending in the lie – a scope guide can be useful in determining this)
• Transverse colon: Supine
• Splenic flexure to rectum: Right lateral

 

What are the problems?

When turning the patient, it is important to monitor the screen to observe any change in colonoscope position, asking the nurses in the room to help instruct and turn the patient. If performing these manoeuvres is new, consider asking an expert colleague to observe a procedure practicing these position changes. Turning the patient shouldn’t. take long, one study showed an additional 44 seconds was required per procedure[27].

The “Colon Map” is shown below:

Click to view full image and download

Rex et al found three features of withdrawal technique, other than withdrawal time, which were associated with better polyp detection[28]. These are:

• Looking on the proximal side of folds and the ileocaecal valve
• Adequacy of cleaning and suction
• Adequacy of distention

Rex and Lee have shown these techniques differentiate endoscopists high and low adenoma miss rate and adenoma detection rates when scored in five areas of the colon[28,29].

So our tips with help from Waye[30]:

• Look behind all folds and the ICV:
• If you fall back, reinsert the colonoscopy to look again.
• If you can’t see, change the patient position to optimize the view.
• Try and clean all pools:
• Rotate fluid to the 6 o’clock position to allow accurate suction
• Use flushes or an irrigator to clear the view.
• If a pool is too thick, change the patient position to move debris and view the underlying mucosa.
• Inflate enough to get clear views
• If the lumen remains collapsed, change the patient’s position.
• If there is spasm, and no contraindication, think about using buscopan.

As unit lead you have the responsibility to work with potentially under-performing endoscopists to identify issues and investigate reasons for under performance.

This may be a role you are experienced in or a new role for this study. Below are some resources and further reading which may help in the role.

 

JAG framework for managing under performance and supporting endoscopists

 

Resource	The joint advisory group on GI endoscopy framework
Publication date	August 2019
Link	https://www.thejag.org.uk/CMS/UploadedDocuments/Scheme/Scheme5/STG190917%20-%20guidance%20-%20UK%20underperformance%20for%20JAG%20v2.0.pdf
Content	A framework for managing under performance more generally in endoscopy, with suggested timelines.

 

The is summarised below in Figure 1: JAG framework for managing endoscopists in difficulty.

 

 

Managing under performance in endoscopy: a pragmatic approach

 

 

Resource	Rees, CJ., Thomas-Gibson, S., Bourke, MJ., et al Managing underperforamnc ein endoscopy: a pragmatic approach. Gastrointestinal Endoscopy 2018; 88(4) 37-744
Publication date	October 2018
Link	Science direct: https://www.sciencedirect.com/science/article/pii/S0016510718328219 GIE: https://www.giejournal.org/article/S0016-5107(18)32821-9/fulltext
Content	Works though identifying issues of underperformance and a strategy for addressing these.

 

Below is a summary flowchart of possible mechanisms for supporting an endoscopist in difficulty, taken from the publication: