Rationale: Chronic abdominal and pelvic pain are highly prevalent in among patients who
had abdominal surgery in history. An estimate of 11-20% of all patients undergoing
different kinds of abdominal surgery will develop chronic abdominal pain. Adhesions (a
form of internal scar tissue) are the most common pathology found in patients undergoing
diagnostic laparoscopy for pain. Other factors that might be associated with chronic
post-operative pain are anxiety, depression, and female sex. Little is known about the
natural course of pain after abdominal surgery, risk factors for developing chronic pain,
and the mechanisms causing pain in patients with adhesions. In this longitudinal study
the investigators will prospectively study the natural course of pain through repeated
measurements, and predictive factors for chronification of pain after different types of
abdominal surgery.
Objective: In Phase 1 the investigators will study the natural course of pain following
abdominal surgery. Primary objective for phase 1 is to assess risk factors for chronic
pain at 12 months after surgery; where chronic pain is defined as daily continues or
intermittent pain with maximal pain scores of 4 or higher during more than 3 months in
accordance to IASP criteria. As a pivotal secondary outcome we will describe and model
the duration (days) of moderate (worst pain score 4 to 6) to severe pain (worst pain
score 7 or higher), and assess factors that impact the chance in painscore using mixed
models. In phase two the investigators will assess the impact of adhesions on chronic
pain. Primary objective for phase two is to compare incidence and extent of adhesions on
cineMRI between patients who developed chronic pain and patients who did not develop
chronic pain at 12 months after surgery.
Study design: This is prospective cohort study, including 1,500 patients scheduled for
elective abdominal surgery. In phase one, patients are asked to fill a comprehensive
questionnaire, including quality of life assessment and a comprehensive assessment of
potential predictive factors for chronic pain prior to surgery. Post-operatively pain
symptoms will be monitored using short daily and weekly questionnaires taken by m-health
and e-health techniques to study natural course of pain. A comprehensive assessment of
pain, quality of life, and medical consumption will be taken at 3,6, and 12 months
post-operatively.
In phase two of the study patients who developed chronic pain will be invited for mapping
of adhesions using cineMRI. Results of mapping of adhesions using cineMRI in patients
with chronic abdominal pain will be compared to mapping of adhesions in 100 patients
matched for type of surgery and risk factors who did not develop chronic pain.
Study population: 1,500 patients undergoing elective abdominal surgery from different
surgical subspecialties (e.g. colorectal, upper-GI, and gynaecological surgery), aged 18
years or older.
Main study parameters/endpoints: Main study outcome for phase one are risk factors for
development of chronic pain at 12 months post-operative. Pivotal secondary outcomes
include description of the median duration (days) of moderate to severe abdominal pain
following abdominal surgery, and modelling of factors that impact change in abdominal
pain after surgery. Other secondary outcomes include health-related quality of life,
healthcare utilization, and return to daily activity or work.
Main outcomes for phase two is the percentage of patients with adhesions on cineMRI as
compared between patients with and without chronic pain. Secondary outcomes relate to the
appearance of adhesions on cineMRI, and included extent and the loss of shear.
Nature and extent of the burden and risks associated with participation, benefit and
group relatedness: In phase one of this cohort study patients will be asked to fill
repeated questionnaires on pain and potential risk factors for chronic pain. The intake
questionnaire prior to surgery will take approximately 60 minutes to fill.
Post-operatively we will send short questionnaires that take 2-5 minutes to fill. These
questionnaires will be send daily during the first 60 days after surgery and weekly
afterwards. A more comprehensive questionnaire on abdominal pain and complaints that
takes 45 minutes to complete will be send at 3,6, and 12 months post-operative. There are
no risks related to participation in this study, nor are there direct benefits.
Patients participating in part two of this cohort will undergo cineMRI to evaluate if
pain symptoms might relate to adhesions form previous surgery. The MRI will take
approximately 20 minutes to perform. MRI is a non-invasive imaging technique without
health risks. However, there is a risk of incidental findings that do not relate to the
subject of this study (adhesion formation). Patients who do not want to be informed about
incidental findings will be excluded from phase two. In a subset female patients who had
pelvic surgery and resection of the uterus an additional transvaginal ultrasound will be
made. Like MRI, this is a non-invasive diagnostic test without health risks. There is
some additional inconvenience by the use of a transvaginal ultrasound prove. The test
will take approximately 15 min.