Obesity and Difficult Colonoscopy
by ColoWrap, on August 15, 2022
Did you know that 1 in 23 men and 1 in 25 women have a lifetime risk of developing colorectal cancer? As the third most diagnosed form of cancer, a tremendous volume of research has gone into identifying the causes, risk factors, early detection techniques, and treatment options for colorectal cancer.
The good news: research indicates that overall colorectal cancer (CRC) incidence and mortality in adults over 50 is down over 45% since the 1980s, largely due to improved screening techniques.
The bad news: the opposite is occurring in younger adults. We’re seeing increased colorectal frequency and fatalities in adults aged 20-49, with some predictions warning that colon cancer will potentially increase as much as 90% among adults aged 20-34 by 2030.
The cause of this alarming trend? Researchers believe obesity to be the most likely culprit.
Obesity can be defined simply as the medical term for an excessive amount of body fat. The exact numerical definition of obesity can vary between nation and medical systems, but for the sake of this article we can assume that a person declared morbidly obese has a total body mass index over 35. Body mass index (BMI) is calculated by dividing a person’s weight by their height squared to provide a relatively accurate indicator of body fatness.
Recent data tells us that over ⅓ of US adults are obese, and researchers believe that this number will to rise to over 40% by 2030. Obesity and chronic excessive weight account for nearly 3 million adult deaths each year, making it the fifth leading cause of mortality in the country.
And this isn’t a problem that is going away any time soon. Data from exercise science researchers revealed that of the 13,800 US adults studied, more than half gained over 5% of their body weight over a ten year period.
Obese people are especially vulnerable to many diseases and conditions: COVID-19 and other respiratory illnesses, high blood pressure, diabetes, sleep apnea, cardiovascular disease, stroke, etc.
With this in mind, researchers have recently turned their attention to trying to understand the relationship between obesity and cancer, and they have found pretty bleak findings. Not only does obesity predispose you to developing colorectal cancer, but it also negatively impacts prevention strategies, procedure success, and overall prognosis.
The Increased Need of Colonoscopy within the Obese Population
The International Agency for Research on Cancer (IARC) found consistent evidence that higher amounts of body fat are associated with an increased risk for a number of cancers. Some data suggests that colorectal cancer (CRC) is 1.3 times as likely to occur in people that are obese. A study of over 85,000 women found that those with a BMI over 30 had a nearly doubled risk of early-onset colorectal cancer compared to women in a healthier weight range. Epidemiological research suggests that excessive body weight is likely related to 30-70% increased risk of colorectal cancer in men.
With the data clearly pointing in the direction of a negative relationship between obesity and cancer, it’s no wonder that US health agencies have begun recommending increased screening of obese men of all ages and obese pre-menopausal women to combat the growing incidence of colorectal cancer.
And as we know well here at ColoWrap, colonoscopy is the gold standard of colorectal cancer screening thanks to its ability to give the colonoscopist a clear view of the entire colon. Increased visibility leads to improved polyp detection and removal which leads to overall improved colorectal cancer outcomes.
A 2012 study tells us that nearly 18% of all colorectal cancer cases were attributable to obesity, lending further support to the argument that a special focus should be given to early screening in obese populations.
However, since the need for colonoscopy in obese populations is indisputable, why is there so much discussion around the difficulty of colonoscopy in these patients?
Well, the answer is complicated.
Unique Challenges of Performing Colonoscopies in Obese Populations
Difficult colonoscopies—procedures where the endoscopist struggles to get through the entire colon or fails to do so entirely—are problematic for a host of reasons, namely longer procedure times, incomplete procedures, and overall higher patient risk. Procedure complications can arise from a whole host of variables such as endoscopist technique, inadequate bowel preparation, redundant colons, staff shortages etc.
Difficult colonoscopies can and do occur in patients of all body types; however, colonoscopists are finding procedures on obese patients to be increasingly challenging.
Endoscopic techniques and maneuvers, such as patient repositioning and applying abdominal pressure, typically required during colonoscopy are much more difficult to perform on obese patients. And when these techniques are not applied effectively, looping is more likely to occur.
Looping, the most common complication in colonoscopy, is what happens when the colonoscope stretches and distends the colon in response to the colonscopist’s attempt to advance the scope forward. Once a loop forms, the procedure typically cannot adequately continue until the loop is addressed.
Currently, the best way to address a loop is for endoscopy nurses and technicians to apply manual abdominal pressure as a way of “splinting the colon.” This is an imperfect solution that often results in musculoskeletal injuries in staff and can result in significant patient discomfort.
Beyond mere discomfort, obese patients are vulnerable to developing tissue injuries, infections, and altered skin integrity due to the abnormal adipose tissue distribution that occurs with an excess of body fat. Repositioning obese patients requires increased labor, training, equipment, and technology to prevent these pressure-based injuries that can result in tissue necrosis.
Splinting the colon and patient positioning are extremely labor-intensive techniques. And due to the frequency of looping, endoscopy staff are routinely expected to perform these high-risk activities that can result in catastrophic workplace injury. The Bureau of Labor Statistics reports that nursing assistants suffer more debilitating back injuries at work than any other single occupation, including warehouse and construction workers.
Beyond the significant risk to patients and endoscopy staff, several studies have suggested that obesity is also linked to inadequate bowel preparation, increasing the risk of missed polyps and procedural complications. This means that not only is the procedure more difficult to perform in obese patients, but that patient outcomes tend to be worse.
Further, overweight and obese patients are associated with significantly higher risks of sedation-related cardiopulmonary complications.
The Effect of Obesity on Colonoscopy
These challenges in performing colonoscopy on obese patients are only going to worsen as the obese population continues to grow. Recent gastroenterology research advises endoscopists to anticipate the likelihood of incomplete colonoscopy, longer procedure times, increased patient discomfort, and poorer tolerance when performing colonoscopy in obese patients. Other studies have shown CRC screening in obese patients to be less accurate, effectively neutralizing the positive patient outcomes typically associated with early detection screening.
Perhaps most alarmingly, researchers have identified an emerging trend of physicians failing to recommend colonoscopy in obese patients, possibly due to associated risks with performing the procedure on obese patients, competing care demands, strain on staff, and obesity-related discrimination.
Patients with Obesity: Making A Difficult Colonoscopy Safer and More Effective
Colonoscopy is more difficult in obese patients, but that doesn’t mean that there aren’t steps that we can take to improve procedure success and colorectal cancer outcomes in bodies of all sizes.
One study suggests that performing colonoscopy with patients placed in the prone position leads to shorter cecal intubation times and reduced need for patient repositioning.
However, other research suggests that the shift to the prone position proves difficult for even seasoned and skilled endoscopists, and that further research is needed to improve colonoscopy outcomes in obese patients.
Additionally, the prone position during surgery is associated with an increased risk for cardiovascular collapse and arrest. The prone position also often results in more looping, which results in more patient repositioning, which results in further risk to staff and patient discomfort - AKA bringing us back to square one.
All of this is to say that the shift to the prone position is not likely the solution to the critical issue of difficult colonoscopy in obese patients.
ColoWrap, however, is a clear step in the right direction. A medical device designed specifically to mitigate looping, ColoWrap improves throughput, reduces cecal intubation time, and empowers organizations to deliver a safer environment for staff and patients regardless of patient BMI. ColoWrap does the heavy lifting for GI personnel by improving endoscopy ergonomics and safe patient handling, leading to greater patient outcomes and overall procedure success.