#353 Colon Polyps

September 12, 2022 | By Elena Gibson

Video

Polyps, polypectomy & surveillance with Dr. Jennifer Maranki

Learn how to recommend a good bowel prep, read colonoscopy reports, and review recommended polyp surveillance with Dr. Jennifer Maranki, @jenmarankimd (Penn State Health)

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Credits

• Producer & Writer: Elena Gibson MD
• Show Notes: Elena Gibson MD
• Infographic & Cover Art: Kate Grant MBChB DipGUMed 
• Hosts: Matthew Watto MD, FACP; Paul Williams MD, FACP   
• Reviewer: Emi Okamoto MD
• Showrunner: Matthew Watto MD, FACP
• Technical Production: PodPaste
• Guest: Jennifer Maranki MD

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CME Partner: VCU Health CE

Show Segments

• Intro, disclaimer, guest bio
• Guest one-liner, Picks of the Week
• Case from Kashlak; definitions
• Polyp definitions and categories 
• Bowel prep & colonoscopy quality
• Colorectal polyp surveillance 
• Potential complications 
• When to consider polyposis syndromes 
• Outro

Colorectal Polyp Pearls

1. Colorectal polyps can be categorized as neoplastic vs non-neoplastic. 
2. Hyperplastic polyps are the most common type of non-neoplastic polyp identified, and they do not have malignant potential. 
3. Neoplastic polyps include adenomas, sessile serrated polyps and rarely hamartomatous polyps. 
4. An advanced adenoma is an adenoma with any of the following three: size ≥10mm, tubulovillous or villous histology, high-grade dysplasia.
5. Potential complications following polypectomy include bleeding, post polypectomy syndrome and bowel perforation. 
6. Bleeding is the most common adverse event following colonoscopy with polypectomy. 
7. Based on the size and type of polyps identified, repeat surveillance is recommended ranging from 1 to 10 years

Colorectal Polyp Show Notes

Types of Polyps 

First categorize polyps based on pathology into neoplastic vs non-neoplastic polyps (Gupta 2020). 

Non-neoplastic polyps include: 

• Hyperplastic polyps: most common non-neoplastic polyp most commonly in the sigmoid and rectum. They do not substantially increase the risk of developing colon cancer.
• Inflammatory polyps: frequently seen in diverticular disease or chronic inflammation
• Hamartomatous polyps: if seen in the setting of a hamartomatous polyposis syndrome these can have malignant potential

Neoplastic polyps include: (categorized by histology)

• Adenocarcinoma
• Tubular adenomas
• Villous adenomas 
• Tubulovillous adenoma 
• Sessile serrated polyps (SSP)

Sessile what?

Sessile serrated polyps (SSP) look similar to hyperplastic polyps on endoscopic evaluation. They are flat or minimally raised polyps with a subtle appearance. They are more frequently located in the proximal colon and microscopically they share many characteristics with hyperplastic polyps but they have more disorganization and serrated edges. SSPs are important to identify because they are easily missed and the presence of sessile serrated polyps increases the odds of developing colon cancer threefold compared to someone with a normal colonoscopy (Erichsen 2016,Gupta 2020). Part of the reason SSPs require closer follow up is because they are more difficult to identify on colonoscopy. 

Size and Location

In addition to the type of polyp, the size of the polyp helps determine the surveillance interval. Polyps range from 2mm (~smallest you can see) to multiple centimeters in size. An important delineation of polyp size is <10mm in size vs. ≥10mm in size. Polyps ≥10mm in size are considered high risk and require closer follow up (Gupta 2020). The location of the polyp doesn’t guide follow up intervals, but it can provide insight into whether there could be a polyposis syndrome. Furthermore large right-sided hyperplastic polyps on pathology report raise Dr. Maranki’s suspicion for the possibility of a sessile serrated polyp as these two polyps can look similar on microscopic evaluation. 

Advanced Adenoma

Advanced adenoma is an adenoma with any of the following 

1. High-grade dysplasia 
2. Size ≥10mm 
3. Tubulovillous or villous histology 

What Makes a High-Quality Colonoscopy?

A high-quality colonoscopy is defined by multiple variables (Keswani 2021). First, the bowel preparation needs to be adequate. Differences in prep depend on local availability, insurance coverage, and comorbidities. Patients should follow a low residue diet 1-2 days prior to the colonoscopy (low fiber, easily digestible foods). Foods to avoid include nuts, dried fruit, berries, seeds, and many vegetables (Mentioned UMH Colonoscopy Guide). Low volume preparation solutions and polyethylene glycol + Gatorade have been associated with improved tolerability (Gu 2019). Below are examples of common preparations: 

1. GoLYTELY: gallon of prep of polyethylene glycol, an osmotic laxative, and electrolytes.
2. Split prep regimen: Studies have shown that splitting prep is superior with ½ taken approximately 12 hours prior to the colonoscopy and ½ taken 6 hours prior with completion at least 2 hours prior to colonoscopy. (Martel, 2015)
3. Low-volume prep (Suprep, MoviPrep, Clenpiq): No Suprep if sulfate allergy or gout. Same with Sutab. 
4. Gatorade + Miralax: well tolerated but not FDA approved for bowel prep. Mix of one bottle of Miralax (8.3 ounces) and 64oz Gatorade/Powerade/G2 (Samarasena 2012). 

For patients with risk factors for inadequate prep such as chronic constipation, diabetes or chronic opiate use, Dr. Maranki recommends a clear liquid diet for multiple days prior to colonoscopy. 

Endoscopic Finesse

In addition to the bowel prep, look for scope advancement to the cecum or terminal ileum in a patient without prior surgery. For the adequacy of bowel prep, at a minimum look for “adequate” bowel prep. This implies the bowel prep was adequate to detect polyps >5mm. There are a variety of scales used to indicate adequate bowel prep such as the Boston Bowel Prep Scale (Lai, 2009). Bowel prep described as “good, excellent or adequate” above the threshold needed  “fair, suboptimal or poor” are red flags which indicate the prep was not adequate to detect polyps. In average-risk patients with good-quality prep, adenomas are identified in at least 30% of men and at least 20% of women during first screening colonoscopy (Rex 2015, Heitman 2009). A minimum of 6 minutes should be spent on withdrawal of the endoscope, as most of the the evaluation for polyps is completed during withdrawal (Rex 2015).

Follow up 

Follow up guidelines assume adequate prep and apply to patients at average risk for colorectal cancer (Gupta 2020). Patients are considered high risk if they have a family history of colon cancer, advanced polyps in a first degree relative, or a personal history of inflammatory bowel disease. 

What Comes After a Polypectomy? 

Based on the size and type of polyps identified, repeat surveillance is recommended ranging from 1 to 10 years (Gupta 2020). Dr. Maranki recommends a number instead of a range when planning a follow up interval for patients to generate improved recall. Factors that push Dr. Maranki to choose the shorter side of the range include family history, size of polyp, and number of polyps. 

Recommended follow up should be adjusted based on findings from the most recent colonoscopy. A decreased maximum interval of 5 years should only be considered for patients at high risk for CRC due to family history. Other methods of CRC screening such as FIT or FIT DNA testing are not recommended for surveillance following polyp detection. 

Figure from the US Multi-Society Task Force on Colorectal Cancer regarding recommendations for follow up after colonoscopy and polypectomy in average risk adults: (Gupta, 2020)

Potential Complications

A colonoscopy is generally a safe and well tolerated procedure (Rex 2015). Risks increase with polypectomy but complications remain rare. Abnormal bleeding occurs in 1-2% post polypectomy, and the incidence can increase to 5-10% following a large polyp resection such as endoscopic mucosal or submucosal for polyps >2cm in size (ASGE 2011). Bleeding can be immediate or delayed, and delayed bleeding (up to 3 weeks after colonoscopy) is more common if electrocautery is used with the snare for polypectomy. Small amounts of bleeding including streaks of blood in stool up to tablespoons of blood can be normal following polypectomy, but it should improve with each bowel movement. 

Perforation is a rare but serious complication, occurring in <<1% patients following a typical polypectomy but up to 5% in the setting of mucosal or submucosal resection (Lohsiriwat, 2010). Post polypectomy syndrome is another potential complication that can present as focal peritonitis symptoms including fever, leukocytosis, or abdominal pain without evidence of perforation. It is usually managed outpatient with supportive care bowel rest but occasionally requires hospitalization (Reumkens 2016).

Links

1. All the Light We Cannot See (book)
2. Tana French Mysteries
3. Hamilton Soundtrack
4. Khruangbin (band/music)
5. Hamilton Polka 

Goal

Listeners will review important characteristics of colon polyps and develop an approach to the updated colon polyp follow up. 

Learning objectives

After listening to this episode listeners will…

1. Define the various types of colorectal polyps 
2. Recognize the differences in characteristics of colorectal polyps 
3. Review the updated guidance on colorectal polyp surveillance 
4. Describe how to accomplish a good bowel prep prior to a colonoscopy

Disclosures

Dr. Maranki receives a consulting fee from Boston Scientific. The Curbsiders report no relevant financial disclosures. 

Citation

Gibson EG, Maranki J, Okamoto EE, Grant K, Williams PN, Watto MF. “#353 Colon Polyps: Polyps, Polepectomy & Surveillance with Dr. Jennifer Maranki”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/episode-list September 12, 2022