EMG evaluation of the Pelvic Floor and Functional Outcomes in patients who underwent Rectal Cancer Treatment

The prognosis of rectal cancer has improved in the last decade. As rectal
cancer patients often survive their disease, functional outcome after rectal
cancer treatment has become increasingly important. Patients without a
permanent colostomy can experience significant rates of faecal incontinence and
other anorectal complaints such as frequency, urgency and flatulence. Moreover,
after rectal cancer treatment urinary incontinence, difficulty in bladder
emptying and sexual dysfunction is seen. These functional outcomes have impact
on quality of life (QoL).
The rectum, anal sphincters, bladder, urethra and pelvic floor muscles are
essential in maintaining faecal and urinary continence. Surgery and
radiotherapy for rectal cancer treatment can cause damage to these components
which can lead to involuntary loss of faeces and urine. In patients with
already existing pelvic floor dysfunction, additional damage to pelvic floor
muscles and pelvic nerves is expected to further impair the continence
mechanism and is expected to result in worse functional outcomes. In short, we
expect pre-treatment function of the pelvic floor to influence post-treatment
functional outcomes.
However, no diagnostic tool is used to objectively measure the function of the
individual muscles of the pelvic floor in patients with rectal cancer. We
expect that measurement of the pelvic floor with electromyography (EMG) is
correlated to patients* postoperative functional outcomes. If so, measurement
of pre-treatment pelvic floor function with EMG may possibly predict the
functional outcomes after rectal cancer treatment, and therefore determine
treatment choices to a certain extent.
In this study the correlation between post-treatment EMG values of the pelvic
floor and post-treatment functional outcomes will be evaluated. When a positive
correlation is found, a successive study will be conducted to determine whether
pre-treatment EMG measurement of the pelvic floor is predictive for the
post-treatment functional outcomes. If so, patients and doctors can be informed
about the expected functional outcomes, which can contribute in decision making
for the surgeon to construct a permanent stoma instead of sphincter
preservation during Low Anterior Resection (LAR) and it can contribute to make
decisions about participating in the organ sparing *wait-and-see* treatment.

To study the correlation between EMG values of the pelvic floor and functional
outcomes of patients who has been treated for rectal cancer in the period
January 2014 till December 2018.

Cross-sectional study.

Patients included in the study will have 1 additional hospital visit that will
last 1 hour. During this visit, an EMG measurement of the pelvic floor will be
performed. This will be done with an small anal probe, the Multiple Array Probe
Leiden (MAPLe).
No risks are associated with the use of the MAPLe.
After the measurement, patients will receive questionnaires about defecation,
micturition and sexual functioning. These questionnaires contain 25 questions
for women and 28 questions for men in total. Patients are able to complete the
questionnaires in a quiet room in the LUMC.
Patients will have no direct benefit from participation in this study.