A groundbreaking study reveals why some patients face greater risks during routine colon cancer screening.
For millions of Americans, colonoscopy is a life-saving procedure for detecting and preventing colorectal cancer through the removal of precancerous polyps. What most patients don't realize is that a hidden factor—chronic kidney disease—can significantly impact the safety of this common procedure. Dr. John Guardiola and his research team have uncovered crucial evidence about who is most at risk for complications after polyp removal, and their findings are changing clinical practice 1 .
Colorectal cancer remains the third most commonly diagnosed cancer and the third leading cause of cancer-related deaths in the United States 1 .
Colorectal cancer remains the third most commonly diagnosed cancer and the third leading cause of cancer-related deaths in the United States. Colonoscopy not only detects this cancer early but also prevents it through the removal of precancerous polyps during the procedure itself 1 .
Meanwhile, chronic kidney disease (CKD) affects millions of Americans, with a 7-10% lifetime risk of developing stage 3 CKD or higher. These patients present a particular challenge: they're more likely to develop colorectal adenomas and advanced adenomas yet may face higher risks during polyp removal 1 .
Life-saving procedure for colorectal cancer detection and prevention
Affects millions with 7-10% lifetime risk of stage 3 CKD or higher
Dr. John Guardiola, an Assistant Professor of Clinical Medicine at Indiana University School of Medicine and gastroenterologist specializing in complex colorectal polyp resection, has spearheaded research addressing this critical intersection of kidney disease and gastrointestinal procedure safety 4 .
Chronic kidney disease involves the gradual loss of kidney function over time. When kidneys don't work properly, they can't effectively filter wastes and excess fluids from the blood. This systemic condition affects nearly every aspect of bodily function, including:
These widespread effects create potential complications during medical procedures that patients and doctors might not anticipate. As Dr. Guardiola's research reveals, the implications for colonoscopy safety are particularly significant 1 .
Dr. Guardiola and colleagues conducted a retrospective cohort study using the U.S. Collaborative Network through the TriNetX platform. Their investigation included 9,196 patients with chronic kidney disease and an equal number of matched controls, all of whom underwent colorectal endoscopic mucosal resection (EMR) 1 .
EMR is the preferred technique for removing large colorectal polyps (≥20 mm) and is frequently used for smaller polyps (10-19 mm) as well. The most common major adverse event following this procedure is post-polypectomy bleeding (PPB) 1 .
The researchers employed one-to-one propensity score matching to ensure fair comparisons between groups, balancing factors like age, race, ethnicity, gender, comorbidities, and medication use. This rigorous methodology allowed them to isolate the effect of kidney disease on procedure risks 1 .
TriNetX Platform
Propensity Score
Statistical Modeling
The study revealed a clear relationship between kidney function and bleeding risk:
| Patient Group | Bleeding Risk | Increased Risk Compared to Controls |
|---|---|---|
| Control Group (No CKD) | 3.8% | Baseline |
| All CKD Patients | 5.4% | 44% higher |
| Non-advanced CKD (Stages 1-3) | 4.7% | 20% higher |
| Advanced CKD (Stages 4-5 & ESRD) | 8.1% | 109% higher |
The results demonstrated that chronic kidney disease significantly increases the risk of post-polypectomy bleeding. While all CKD patients showed elevated risk, those with advanced kidney disease faced more than double the risk compared to patients without kidney problems 1 .
This risk gradient highlights the importance of considering not just whether a patient has kidney disease, but how severe it is when planning colorectal procedures.
The research team also examined other serious complications, finding that CKD patients required more endoscopic reinterventions for hemostasis and more blood transfusions following their procedures 1 .
| Complication Type | Findings in CKD Patients | Clinical Significance |
|---|---|---|
| Endoscopic Reintervention | Increased need | Requires repeat procedure to control bleeding |
| Blood Transfusions | Higher rates | Indicates more severe bleeding episodes |
| ICU Admissions | Trend toward increase | Suggests more serious complications |
These findings indicate that the bleeding events in CKD patients aren't merely minor inconveniences but represent clinically significant complications that require additional interventions and medical resources 1 .
The comprehensive nature of this research relied on several key resources and methodologies:
Provided access to de-identified electronic health records from multiple healthcare organizations
Balanced demographic and clinical factors between groups for fair comparison
Identified patients with chronic kidney disease and related conditions
Identified procedures including endoscopic mucosal resection
Calculated odds ratios, confidence intervals, and determined statistical significance
Dr. Guardiola's research carries important implications for clinical practice:
Patients with CKD, particularly advanced CKD, may benefit from specialized preparation and management before undergoing colorectal polyp removal.
Patients with kidney disease should be appropriately counseled about their elevated risks when considering polyp removal procedures.
Closer observation after the procedure may be warranted for CKD patients to promptly identify and manage bleeding complications.
The findings support tailoring treatment approaches based on a patient's kidney function rather than applying a one-size-fits-all strategy.
Dr. Guardiola's expertise in this area stems from his specialized training and clinical focus.
After completing his gastroenterology fellowship at Indiana University where he served as chief fellow, he joined the faculty in 2023. His primary academic interests include endoscopic resection of complex colorectal polyps and the completion of difficult colonoscopies, making him particularly well-suited to investigate this important clinical question 4 .
His research portfolio demonstrates a consistent focus on procedure safety and optimization. In addition to the CKD study, he has published research on the success and safety of conventional endoscopic resection techniques for previously partially resected colorectal polyps and the characterization of endoscopic features of the ileocecal valve 4 .
This groundbreaking research opens several avenues for future investigation:
Developing specific protocols for managing antiplatelet and anticoagulant medications in CKD patients undergoing endoscopic procedures
Exploring whether technical modifications during polyp removal could reduce bleeding risks in vulnerable populations
Investigating the underlying mechanisms that make CKD patients more susceptible to bleeding complications
Examining whether similar risk patterns exist for other endoscopic procedures
As Dr. Guardiola noted in his correspondence in the American Journal of Gastroenterology, understanding these risk factors is essential for improving patient outcomes 3 .
The work of Dr. John Guardiola and his colleagues represents a significant advance in our understanding of how chronic conditions affect procedural risks. By identifying chronic kidney disease as a key factor in post-polypectomy bleeding, their research enables more personalized, safer care for patients undergoing colorectal polyp removal.
This study reminds us that in medicine, considering the whole patient—not just the primary procedure—is essential for optimal outcomes.
As research continues to uncover these important connections, patients and doctors can make better-informed decisions together, balancing benefits and risks based on solid evidence.
For the millions of Americans living with chronic kidney disease, these findings offer reassurance that their specific needs are being recognized and addressed in gastrointestinal care—ultimately leading to safer colon cancer prevention strategies for all patients.