Transanal Irrigation for the Management of Early Low Anterior Resection Syndrome (LARS)

Colorectal cancer is the third most common cancer in the U.S. with 152,810 new cases estimated for 2024. Rectal cancer comprises one-third of all incident cases, with rising incidence among young individuals (1-2% rise/year). With advances in multidisciplinary management, the overall, 5-year survival has improved (68%), and for localized rectal cancers it is excellent (90%), creating a growing rectal cancer survivorship population (currently >450,000). Traditionally, surgery for rectal cancer required removal of the rectum and the anus, with the creation of a permanent ostomy. However, with recent advances in subspecialty training and technique, in combination with neoadjuvant radiation, surgeons can offer a cure while preserving the anal sphincter and restoring bowel continuity, via a newer technique called Low Anterior Resection (LAR). This technique, favored by surgeons and patients, aims to allow patients to have an option of remaining "close to normal", as opposed to having a permanent ostomy. While this technique has been successful in sparing the rectum, these advancements have not come without consequence. Bowel dysfunction post-LAR, known as Low Anterior Resection Syndrome (LARS), is perhaps the most prevalent and significant sequela, affecting up to 70-90% of rectal cancer survivors. LARS symptoms include fecal incontinence, urgency, increased frequency, stool fragmentation, and incomplete evacuation. These uncontrolled LARS symptoms have a devastating impact on patients' quality of life (QoL), and often persist indefinitely. Treatment for LARS focuses on symptom management, using diet, medications and pelvic floor physiotherapy, but these measures often fail leaving patients with significant symptoms. Consequently, many patients are unable to return to work in their prior roles and require long-term disability or early retirement. Patients also resort to lifestyle restrictions including skipping meals, restricting social and recreational activities, and avoiding travel and exercise, thereby further diminishing their QoL .

Transanal irrigation (TAI) is an established treatment used for fecal incontinence and constipation. TAI is designed to irrigate a large amount of water throughout the entire colon, allowing for scheduled and complete emptying of stool. As such, TAI has the potential to reduce the symptoms of LARS including difficulty emptying, incontinence, and frequent, unpredictable bowel movements. This single daily irrigation is designed to allow patients to be free of bowel movements during the day and reduce their dependency on immediate access to the toilet, thus decreasing the impact of LARS on their daily lives. Currently, TAI is not in wide clinical use for LARS in North America despite reports from small prospective European studies (15-37 patients) demonstrating benefits for LARS . The most recent and robust published study to date, included patients with late LARS (>1-year post-treatment) randomized to TAI (n=16) vs. control (n=22), and reported significant improvements in LARS and QoL at 1 year when using TAI.

Prior work: Investigators have conducted a multi-center, cross-over, pragmatic randomized controlled trial (RCT) to assess TAI for late LARS (median 2 years post-treatment) at 7 Canadian institutions (NCT04469426). The trial has completed accrual (n=71). Patients were randomized (1:1 ratio) to start in either the TAI or control group, and then crossed over to the opposite group. Participants spent 3 months in each arm. Participants in the TAI arm received nursing instruction and online education for learning TAI using the "LARS-TAI" app. I created this web-based HIPAA-compliant, mobile app (iOS™ and Android™ compatible) to support patients with LARS using TAI. The LARS-TAI App is accessible on any device with internet access or cellular data, including smart phones, tablets, and computers. The app contains educational modules on LARS and TAI, a discussion forum, patient videos, and bowel diaries. Investigators are currently completing follow-up and data analysis for this study. This cross-over trial has provided invaluable practical knowledge on educating patients about TAI and has demonstrated a high level of acceptance for TAI as a treatment for LARS within the first North American sample. Furthermore, it has underscored the challenges associated with a cross-over study design, as many participants were hesitant to transition from TAI to the control group due to the marked improvements in LARS and QoL that they experienced with the intervention.

At CCF-FL, I have established a LARS Clinic, with a trained LARS nurse, and investigators have treated over 50 rectal cancer patients with LARS in 2024. Investigators have established a LARS registry and are routinely screening for LARS in our rectal cancer patients. Investigators have partnered with CCF-Ohio who have also started screening rectal cancer patients for LARS. Investigators have identified a high burden (75% major LARS) of LARS post-treatment in our rectal cancer patients.

The knowledge gap: While TAI shows promise for LARS management, the optimal timing for its use remains unclear. The first 6 months post-treatment pose significant challenges for LARS patients, with at least 58% experiencing major LARS and significantly decreased quality of life (QoL). Investigators observed that 54% of these patients with major LARS also experience financial distress, with most unable to return to work. Unfortunately, conservative measures often fail in this early phase, rendering patients in despair as they try to adapt to their altered bowel function. The potential for TAI to improve LARS in this early phase was proposed in a small German RCT (n=37) that demonstrated reduced bowel movements and improved LARS with no significant complications .

Overall, TAI has only been reported in 9 published studies (total n=204) all from outside of the US, including only 3 small RCTs (total n=102). Although these trials are somewhat limited in size and design, taken together they represent important evidence for the benefit of TAI in LARS and are the basis for pursuing a larger North American RCT. TAI is promising for decreasing LARS and improving QoL. Despite this available evidence on the potential benefits of TAI for LARS, TAI is currently not in standard clinical use for LARS in North America due to limited North American data. As such, TAI for the indication of LARS is not available to patients and current insurance plans (medicare/medicaid or private) do not cover its cost. This pilot trial aims to assess the feasibility of a larger trial that will build on the foundation of evidence that supports the use of TAI in rectal cancer patients with LARS. In this pilot and subsequent larger trial, investigators will gather North American data to support the use of TAI in a North American population, especially in the early post-treatment period.

Expected Results: Investigators hypothesize that TAI will decrease early LARS and positively impact quality of life for rectal cancer patients. Investigators aim to transition into a phase III study, with pilot study cases contributing to the larger sample. This strategy optimizes pilot study data use, maintains research momentum, and builds on initial findings. Successful pilot completion will yield data affirming TAI's feasibility and potential efficacy in managing LARS, bolstering our applications for extramural funding (NIH R01 Research Project Grant).

Impact: More than 450,000 rectal cancer patients in the US will enter survivorship for rectal cancer this year, with a rising number of younger patients of working age affected by rectal cancer. TAI may help patients significantly control their symptoms from the early post-operative period, allowing them to return to work and normal activities sooner and improve their QoL. The success of this pilot and consequently our larger trial will provide the necessary evidence to incorporate TAI into standard practice for LARS treatment.