Low anterior resection syndrome (LARS)
- Jacopo Martellucci, MD, PhD
Jacopo Martellucci, MD, PhD
Surgery is the only curative therapy for rectal cancer. Transabdominal surgery can be performed with either sphincter-sparing techniques (ie, anterior resection) or an abdominal perineal resection. Historically, abdominal perineal resection was the gold standard for treating low-lying rectal cancers. With the advent of better surgical techniques and equipment (eg, staplers) as well as neoadjuvant therapy, abdominal perineal resection has been gradually replaced by sphincter-sparing procedures. For patients in whom a negative distal margin can be achieved, sphincter-sparing procedures are preferred because they maintain bowel continence and avoid a permanent colostomy. In contemporary practices, sphincter-sparing procedures are feasible in up to 80 percent of patients requiring surgery for rectal cancer.
However, functional disturbances constitute a major problem for many surviving rectal cancer patients following a sphincter-sparing procedure, with symptoms ranging from daily episodes of incontinence to obstructed defecation and constipation. Although such symptoms have an immense impact on the patients' quality of life, there is presently no specific treatment. Instead, management is empirical and symptom based, using existing therapies for fecal incontinence, fecal urgency, and rectal evacuatory disorders.
In this topic, we discuss the clinical manifestations, diagnosis, and treatment of bowel symptoms that develop following sphincter-sparing resections of the rectum. Such symptoms have been collectively referred to as low anterior resection syndrome (LARS). The techniques of sphincter-sparing resection and the treatment of fecal incontinence, urgency, or other rectal evacuatory disorders of the gastrointestinal tract not necessarily related to surgery are discussed separately. (See "Rectal cancer: Surgical techniques" and "Fecal incontinence in adults: Management" and "Management of chronic constipation in adults".)
Low anterior resection syndrome is a constellation of symptoms, such as fecal incontinence or urgency, frequent or fragmented bowel movements, emptying difficulties, and increased intestinal gas, that occur after a sphincter-sparing resection (ie, anterior resection) of the rectum.
EPIDEMIOLOGY AND RISK FACTORS
It is estimated that between 25 and 80 percent of patients develop one or more symptoms of LARS following a sphincter-sparing rectal surgery. For individual patients, symptoms vary in type, severity, and duration as a reflection of different underlying etiologies.
- Chen TY, Wiltink LM, Nout RA, et al. Bowel function 14 years after preoperative short-course radiotherapy and total mesorectal excision for rectal cancer: report of a multicenter randomized trial. Clin Colorectal Cancer 2015; 14:106.
- Ekkarat P, Boonpipattanapong T, Tantiphlachiva K, Sangkhathat S. Factors determining low anterior resection syndrome after rectal cancer resection: A study in Thai patients. Asian J Surg 2016; 39:225.
- Koda K, Saito N, Seike K, et al. Denervation of the neorectum as a potential cause of defecatory disorder following low anterior resection for rectal cancer. Dis Colon Rectum 2005; 48:210.
- Lee WY, Takahashi T, Pappas T, et al. Surgical autonomic denervation results in altered colonic motility: an explanation for low anterior resection syndrome? Surgery 2008; 143:778.
- Kimura H, Shimada H, Ike H, et al. Colonic J-pouch decreases bowel frequency by improving the evacuation ratio. Hepatogastroenterology 2006; 53:854.
- Emmertsen KJ, Bregendahl S, Fassov J, et al. A hyperactive postprandial response in the neorectum--the clue to low anterior resection syndrome after total mesorectal excision surgery? Colorectal Dis 2013; 15:e599.
- Bregendahl S, Emmertsen KJ, Fassov J, et al. Neorectal hyposensitivity after neoadjuvant therapy for rectal cancer. Radiother Oncol 2013; 108:331.
- Brown CJ, Fenech DS, McLeod RS. Reconstructive techniques after rectal resection for rectal cancer. Cochrane Database Syst Rev 2008; :CD006040.
- Farouk R, Duthie GS, Lee PW, Monson JR. Endosonographic evidence of injury to the internal anal sphincter after low anterior resection: long-term follow-up. Dis Colon Rectum 1998; 41:888.
- Emmertsen KJ, Laurberg S. Low anterior resection syndrome score: development and validation of a symptom-based scoring system for bowel dysfunction after low anterior resection for rectal cancer. Ann Surg 2012; 255:922.
- Temple LK, Bacik J, Savatta SG, et al. The development of a validated instrument to evaluate bowel function after sphincter-preserving surgery for rectal cancer. Dis Colon Rectum 2005; 48:1353.
- Lazaraki G, Chatzimavroudis G, Katsinelos P. Recent advances in pharmacological treatment of irritable bowel syndrome. World J Gastroenterol 2014; 20:8867.
- Cohen LD, Levitt MD. A comparison of the effect of loperamide in oral or suppository form vs placebo in patients with ileo-anal pouches. Colorectal Dis 2001; 3:95.
- Hallgren T, Fasth S, Delbro DS, et al. Loperamide improves anal sphincter function and continence after restorative proctocolectomy. Dig Dis Sci 1994; 39:2612.
- Wedlake L, Thomas K, Lalji A, et al. Effectiveness and tolerability of colesevelam hydrochloride for bile-acid malabsorption in patients with cancer: a retrospective chart review and patient questionnaire. Clin Ther 2009; 31:2549.
- Odunsi-Shiyanbade ST, Camilleri M, McKinzie S, et al. Effects of chenodeoxycholate and a bile acid sequestrant, colesevelam, on intestinal transit and bowel function. Clin Gastroenterol Hepatol 2010; 8:159.
- Itagaki R, Koda K, Yamazaki M, et al. Serotonin (5-HT3) receptor antagonists for the reduction of symptoms of low anterior resection syndrome. Clin Exp Gastroenterol 2014; 7:47.
- Lin HC. Small intestinal bacterial overgrowth: a framework for understanding irritable bowel syndrome. JAMA 2004; 292:852.
- Stephens JH, Hewett PJ. Clinical trial assessing VSL#3 for the treatment of anterior resection syndrome. ANZ J Surg 2012; 82:420.
- Rosen H, Robert-Yap J, Tentschert G, et al. Transanal irrigation improves quality of life in patients with low anterior resection syndrome. Colorectal Dis 2011; 13:e335.
- Koch SM, Rietveld MP, Govaert B, et al. Retrograde colonic irrigation for faecal incontinence after low anterior resection. Int J Colorectal Dis 2009; 24:1019.
- Pucciani F, Ringressi MN, Redditi S, et al. Rehabilitation of fecal incontinence after sphincter-saving surgery for rectal cancer: encouraging results. Dis Colon Rectum 2008; 51:1552.
- Lin KY, Granger CL, Denehy L, Frawley HC. Pelvic floor muscle training for bowel dysfunction following colorectal cancer surgery: A systematic review. Neurourol Urodyn 2015; 34:703.
- Liu CH, Chen CH, Lee JC. Rehabilitation exercise on the quality of life in anal sphincter-preserving surgery. Hepatogastroenterology 2011; 58:1461.
- Laforest A, Bretagnol F, Mouazan AS, et al. Functional disorders after rectal cancer resection: does a rehabilitation programme improve anal continence and quality of life? Colorectal Dis 2012; 14:1231.
- Kim KH, Yu CS, Yoon YS, et al. Effectiveness of biofeedback therapy in the treatment of anterior resection syndrome after rectal cancer surgery. Dis Colon Rectum 2011; 54:1107.
- Allgayer H, Dietrich CF, Rohde W, et al. Prospective comparison of short- and long-term effects of pelvic floor exercise/biofeedback training in patients with fecal incontinence after surgery plus irradiation versus surgery alone for colorectal cancer: clinical, functional and endoscopic/endosonographic findings. Scand J Gastroenterol 2005; 40:1168.
- Thin NN, Horrocks EJ, Hotouras A, et al. Systematic review of the clinical effectiveness of neuromodulation in the treatment of faecal incontinence. Br J Surg 2013; 100:1430.
- Michelsen HB, Christensen P, Krogh K, et al. Sacral nerve stimulation for faecal incontinence alters colorectal transport. Br J Surg 2008; 95:779.
- Michelsen HB, Worsøe J, Krogh K, et al. Rectal motility after sacral nerve stimulation for faecal incontinence. Neurogastroenterol Motil 2010; 22:36.
- Matzel KE, Stadelmaier U, Bittorf B, et al. Bilateral sacral spinal nerve stimulation for fecal incontinence after low anterior rectum resection. Int J Colorectal Dis 2002; 17:430.
- Ratto C, Grillo E, Parello A, et al. Sacral neuromodulation in treatment of fecal incontinence following anterior resection and chemoradiation for rectal cancer. Dis Colon Rectum 2005; 48:1027.
- Jarrett ME, Matzel KE, Stösser M, et al. Sacral nerve stimulation for faecal incontinence following a rectosigmoid resection for colorectal cancer. Int J Colorectal Dis 2005; 20:446.
- Melenhorst J, Koch SM, Uludag O, et al. Sacral neuromodulation in patients with faecal incontinence: results of the first 100 permanent implantations. Colorectal Dis 2007; 9:725.
- Holzer B, Rosen HR, Zaglmaier W, et al. Sacral nerve stimulation in patients after rectal resection--preliminary report. J Gastrointest Surg 2008; 12:921.
- de Miguel M, Oteiza F, Ciga MA, et al. Sacral nerve stimulation for the treatment of faecal incontinence following low anterior resection for rectal cancer. Colorectal Dis 2011; 13:72.
- Moya P, Arroyo A, Soriano-Irigaray L, et al. Sacral nerve stimulation in patients with severe fecal incontinence after rectal resection. Tech Coloproctol 2012; 16:263.
- Schwandner O. Sacral neuromodulation for fecal incontinence and "low anterior resection syndrome" following neoadjuvant therapy for rectal cancer. Int J Colorectal Dis 2013; 28:665.
- Ramage L, Qiu S, Kontovounisios C, et al. A systematic review of sacral nerve stimulation for low anterior resection syndrome. Colorectal Dis 2015; 17:762.
- EPIDEMIOLOGY AND RISK FACTORS
- Colonic dysmotility
- Neorectal reservoir dysfunction
- Anal sphincter dysfunction
- CLINICAL MANIFESTATIONS
- DIAGNOSIS AND DIFFERENTIAL DIAGNOSIS
- DIAGNOSTIC EVALUATION
- Patient questionnaires
- Anorectal/colonic manometry
- Minor LARS
- - Diarrhea
- - Postprandial urgency or incontinence
- - Gas and bloating
- - Fecal soilage
- - Ineffective medical treatments
- Major LARS
- - Transanal irrigation
- - Pelvic floor rehabilitation
- - Neurostimulation
- - Surgery
- SUMMARY AND RECOMMENDATIONS