60
Crohn’s Disease Activity Index (CDAI) score suggesting a significant discordance
between clinical symptoms and endoscopic findings in POR (Table 5.1) [ 7 ]. As
such, relying on patient-reported symptoms to detect POR can miss a significant
portion of affected patients. Ultimately, postoperative CD recurrence can be thought
of on a continuum of endoscopic, clinical, and surgical recurrence.
Detecting Postoperative Recurrence
Endoscopy
Given the lack of overt clinical symptoms in many patients with POR, multiple
methods of POR detection have been investigated. Endoscopy is perhaps the most
well studied. The importance in detecting endoscopic recurrence of CD lies in the
downstream effects. Rutgeerts et al. demonstrated that endoscopic disease severity
at 1 year directly correlated with progression to symptomatic recurrence and most
strongly predicted clinical outcomes [ 3 ]. The authors then suggested an endoscopic
grading system, the Rutgeerts score, identifying key endoscopic findings (Table 5.2)
that correlated with outcomes. The Rutgeerts scoring system defines disease sever-
ity based on the extent of aphthous ulceration in the neoterminal ileum. Absence of
lesions is classified as Rutgeerts i0, five or fewer aphthous ulcers; i1, more than five
aphthous lesions with normal intervening mucosa or larger skip lesions; or i2,
lesions confined to the ileocolonic anastomosis. Diffuse neoterminal ileitis defines
i3, and the addition of large ulcers (≥5 mm), nodules, and/or luminal narrowing
delineates the most severe classification, i4.
For patients with Rutgeerts score i0 or i1 at 1 year, only 8.6% had clinical symp-
toms at 8 years [ 3 ]. Conversely, patients with Rutgeerts score i4 had a 100% symp-
tomatic recurrence rate at only 4 years. Those with severe endoscopic recurrence
(i3–i4) were the most likely to progress to another Crohn’s disease-related surgery
[ 3 , 8 , 9 ]. Consequently, postoperative clinical studies have designated endoscopic
recurrence using the Rutgeerts scoring system as i2–i4, whereas endoscopic
remission includes i0–i1. This designation of endoscopic recurrence or remission
Table 5.1 Types of
recurrence rates from time of
resection in Crohn’s disease
Time post-resection
1 year Clinical 0–44%
Endoscopic 0–84%
Surgical 4–25%
5 years Clinical 32%
Endoscopic 55–77%
Surgical 4–25%
10 years Clinical 52%
Endoscopic 74%
Surgical 12–57%
Adapted from Connelly et al. [ 60 ]B.H. Click and M. Regueiro