What is LAR Treatment?
LAR treatment, or Low Anterior Resection, is a major surgical procedure for treating rectal cancer. During this operation, a colorectal surgeon removes the portion of the rectum that contains the tumor, along with a margin of healthy tissue and nearby lymph nodes. The primary goal of LAR is to reconnect the remaining healthy bowel ends (a process called anastomosis), allowing the patient to maintain normal bowel function and potentially avoid a permanent ostomy.
The viability of LAR depends on several factors, most importantly the location of the tumor. If the cancer is located high enough in the rectum, away from the anal sphincter muscles, a surgeon can perform the resection and reconnection without compromising bowel control. However, if the tumor is too low, another procedure, such as an abdominoperineal resection (APR), may be necessary, which results in a permanent colostomy.
The Surgical Procedure
LAR can be performed using different techniques, determined by the surgeon based on the tumor's characteristics and the patient's overall health.
- Open surgery: Involves one longer incision in the abdomen to allow the surgeon direct access to the rectal area.
- Minimally invasive surgery: Utilizes several small incisions through which the surgeon inserts a camera (laparoscope) and specialized instruments. Some surgeons may use robotic assistance for greater precision. Minimally invasive approaches often result in less blood loss, less pain, and a faster recovery.
Regardless of the technique, the steps generally include:
- Anesthesia: The patient is placed under general anesthesia.
- Removal of cancerous tissue: The surgeon removes the tumor, along with a portion of the rectum and associated lymph nodes.
- Anastomosis: The remaining colon is pulled down and reconnected to the remaining part of the rectum or anus using staples or sutures. This new connection is called the anastomosis.
- Temporary ostomy (if needed): In some cases, especially if neoadjuvant (pre-surgery) radiation or chemotherapy was performed, a temporary ileostomy may be created. This involves bringing a section of the small intestine through an opening in the abdomen to allow the anastomosis to heal completely without being irritated by passing stool. The ileostomy is typically reversed in a subsequent surgery after about 8 weeks.
Low Anterior Resection Syndrome (LARS)
Following LAR surgery, a significant number of patients experience changes in their bowel function, collectively known as Low Anterior Resection Syndrome, or LARS. The symptoms of LARS can vary widely in severity and are caused by a combination of factors related to the surgery and the body's recovery.
Causes of LARS
- Reduced Rectal Reservoir Capacity: The removal of part of the rectum means less space for stool to be stored before evacuation. This can lead to increased frequency of bowel movements.
- Nerve Damage: Surgical manipulation in the pelvic area can damage the nerves that control bowel function, impacting coordination and sensation.
- Sphincter Dysfunction: The anal sphincter muscles, which control bowel movements, may not function as effectively after the procedure.
- Altered Sensation: Patients may have a decreased ability to differentiate between gas and stool, or experience a more sudden and urgent need to defecate.
Symptoms of LARS
- Frequent bowel movements
- Urgency to defecate
- Fecal incontinence (leakage of stool)
- Clustering of stools (multiple, small bowel movements within a short period)
- Constipation alternating with frequent stools
- Increased gas or bloating
- Pain or discomfort in the rectal area
It is important for patients and their care teams to discuss LARS, as management strategies can significantly improve quality of life.
Management Strategies for LARS
Managing LARS is a multi-pronged approach that often begins with non-surgical therapies. The optimal strategy depends on the type and severity of symptoms.
Lifestyle and Dietary Modifications
Dietary changes are often the first line of defense for managing LARS symptoms.
- Dietary Fiber: Increasing intake of soluble fiber, such as psyllium, can help make stools firmer and reduce urgency and clustering. Conversely, consuming too much insoluble fiber can worsen symptoms like bloating and frequency.
- Trigger Foods: Patients are often advised to avoid common triggers that cause softer stools, gas, or diarrhea, including caffeine, alcohol, spicy foods, and fatty meals. Keeping a food diary can help identify individual triggers.
- Small, Frequent Meals: Eating smaller meals more frequently throughout the day can help prevent the digestive system from becoming overwhelmed.
- Hydration: Sipping fluids slowly throughout the day, rather than drinking large amounts at once, can help maintain hydration and avoid worsening diarrhea.
Medications
Several medications can help manage specific LARS symptoms.
- Antidiarrheal Agents: Medications like loperamide can help reduce the frequency and looseness of stools.
- Bulking Agents: Soluble fiber supplements can improve stool consistency.
- Antispasmodics: These can help relieve abdominal cramping and pain.
Physical Therapy and Biofeedback
Pelvic floor physical therapy, guided by a specialist, can help strengthen the muscles involved in bowel control.
- Pelvic Floor Muscle Training: Exercises designed to restore strength and coordination to the pelvic floor muscles.
- Biofeedback Training (BFT): Uses sensors to help patients gain awareness and control of their pelvic floor muscles.
- Rectal Balloon Training: Involves inserting a small balloon into the rectum and gradually increasing its volume to help retrain rectal sensation and capacity.
Advanced Procedures
For severe LARS that does not respond to initial therapies, more advanced treatments may be considered.
- Transanal Irrigation (TAI): A procedure that uses a catheter to introduce water into the colon via the anus to empty the bowel at a predictable time.
- Sacral Nerve Stimulation (SNS): A small device is implanted to stimulate the nerves that control the bowel and anus, which can improve bowel control and incontinence.
- Colostomy: In rare cases where other treatments are unsuccessful, a permanent colostomy may be considered as a final option.
Comparison of LAR vs. Abdominoperineal Resection (APR)
| Feature | Low Anterior Resection (LAR) | Abdominoperineal Resection (APR) |
|---|---|---|
| Surgical Goal | Remove the cancerous portion of the rectum while preserving the anal sphincter. | Remove the rectum, anus, and surrounding tissues, including the sphincter muscle. |
| Tumor Location | Used for tumors located in the upper or middle parts of the rectum, safely above the anal sphincter. | Required for very low-lying tumors that involve or are very close to the anal sphincter. |
| Anal Sphincter | Preserved. | Removed. |
| Ostomy Status | A temporary ostomy may be created during recovery, but a permanent one is typically avoided. | A permanent colostomy is required. |
| Post-Operative Function | Patients may experience changes in bowel habits known as Low Anterior Resection Syndrome (LARS). | Bowel movements are fully managed via the permanent colostomy. |
| Recovery Implications | Requires management of LARS symptoms, which can affect quality of life but often improve over time. | Adapting to and caring for a permanent colostomy is a key part of recovery. |
Conclusion
LAR treatment, or Low Anterior Resection, is a vital surgical option for many patients diagnosed with rectal cancer. By removing the diseased part of the rectum while preserving the anal sphincter, it provides a chance to maintain a higher quality of life by avoiding a permanent ostomy. However, patients must be prepared for the possibility of Low Anterior Resection Syndrome (LARS), which can significantly impact bowel function. Fortunately, a wide range of management strategies—from simple dietary adjustments to advanced physical therapy and procedures—can help mitigate LARS symptoms and allow for a more predictable and comfortable "new normal." It is crucial for patients undergoing this procedure to work closely with their medical team to understand and address any post-surgical challenges effectively. Learn more about the procedure from a trusted source, such as the Johns Hopkins Medicine guide to Low Anterior Resection Syndrome.
