Resident's corner: low anterior resection syndrome: review

Abstract

Context: Low anterior resection syndrome (LARS) is a common debilitating problem faced by patients who underwent low or ultralow anterior resection. The management of LARS is complicated by the fact that our understanding of the pathophysiology of this disease is as yet unclear. In fact, our limitation in understanding is highlighted by the fact that only in 2020 has there been an international consensus on the definition of LARS (LARS international collaborative group). Evidence Acquisition:A comprehensive review of the current literature on the pathophysiology, risk factors and management of LARS was performed. Results:In this review, we discuss the suspected pathophysiology of LARS, including damage to anatomy (sphincter, hiatal ligament, conjoint longitudinal ligamaent), loss of physiology (of rectum), and damage to nervous system (damage to hypogastric nerves, denervation of left colon, loss of recto-sigmoid brake). The risk factors for LARS are discussed, including neoadjuvant treatment, TME dissection, rectal stump height, anastomotic leak, as well as the protective role of a pouch formation in reducing the rate of LARS. Management of LARS involves management of symptoms, and management of underlying neurophysiology. The non operative measures include dietary restrictions, medications to reduce motility, pelvic floor exercises, colonic irrigations. Interventional approaches includes sacral nerve stimulation (SNS), and when bowel function becomes too debilitating a stoma may be created.Conclusion: LARS is a significant and debilitating disorder. It has complex pathophysiology and there are some definite risk factors. Management involves non-operative and operative approaches, trans-anal irrigation and sacral nerve stimulation showing promise.