چکیده (انگلیسی):

Background/Objective: Defective defecation function, also known as low anterior
resection syndrome (LARS), is a common problem after surgical treatment of rectal cancer that
has a detrimental effect on quality of life. This study aimed to look for the incidence of LARS in
patients whose native rectum could not be kept and determine factors influencing major LARS.
Methods: Rectal cancer patients who underwent tumor removal with mesorectal excision and
colorectal anastomosis by a colorectal surgeon during the years 2004e2013 were asked to
participate a structured interview using the verified version of the Low Anterior Resection
Score questionnaire. Clinical parameters were analyzed against the incidence of major LARS.
The cut-off anastomotic level that corresponded to the risk of major LARS was calculated by
using a receiver operating characteristic curve. Anorectal physiology was compared between
those with major LARS and those without LARS by anorectal manometry.
Results: This study included 129 patients (67 men and 62 women). Incidences of minor LARS
(LAR score 21e29) and major LARS (LARS score
30) score 21een those with major LARS
and those univariate analysis, factors associated with major LARS were extent of operation,
presence of temporary ostomy, and chemoradiation therapy. Major LARS was found at 28.2%
in those who underwent low anterior resection, which was significantly higher than the incidence
of 5.2% in the anterior resection group (p < 0.01). Radiation therapy was the only factor
independently associated with major LARS at an odds ratio of 6.55 (95% confidence interval:
2.37e18.15). The receiver operating characteristic curve plot between sensitivity and speci-
ficity of the anastomotic level in determining major LARS showed an area under the curve
of 0.73. The cut-off anastomotic level that best predicted major LARS was at 5 cm, which gave a negative predictive value of 89%. Individual defecation symptoms that were significantly
associated with major LARS included pain on defecation, difficulty holding stool, and needing
to use a pad. Anorectal manometry showed a significant difference in the resting anal pressure
and squeeze pressure, which suggests that derangement in sphincteric function caused by surgery
and postoperative adjuvant treatment may contribute to the LARS.
Conclusion: LARS is a significant problem found in about one third of rectal cancer patients after
colorectal anastomosis. Symptoms of concern include pain on defecation and decreased
ability to hold. Risk of having major LARS increases with adjuvant treatment and lower anastomotic
level.