Relevance of dynamic studies with magnetic resonance enterography in Crohn's disease.

INTRODUCTION: A proper quantification of the inflammatory activity in Crohn's disease (CD) lesions is needed to establish the appropriate management for each patient. The aim of this study is to evaluate the inflammatory activity of affected segments in small bowel lesions using dynamic studies of magnetic resonance enterography (MRE) in patients undergoing surgery, and their correlation with the level of inflammation and histological fibrosis of the surgical piece. METHODS: A prospective, consecutive, observational, clinical study was conducted that included all the patients with small bowel CD that underwent surgery in this center between March 2011 and September 2013. Diagnosis was established according to Lennard-Jones criteria and the Montreal classification. All the patients underwent MRE within three months before surgery, using a routine protocol involving Liver Acquisition with Volume Acceleration-Extended Volume (LAVA-XV) sequence for the dynamic studies before intravenous administering of gadolinium and 30, 70, 120, and 420s after administering this. The results allowed the designing of graphics with different uptake patterns. The Chiorean classification was used in the histological analysis, as well as a modified version published previously by this study group. RESULTS: A total of 28 patients with 47 lesions were analyzed. There was a significant correlation between both curve patterns, including the modified Chiorean classification (P<0.0001) as well as the level of inflammation (P<0.0001) and fibrosis (P<0.002). Inflammatory patterns of dynamic studies are related to histological findings with 80.9% accuracy (sensitivity=75.7%; specificity=100%). CONCLUSION: There is a high correlation between dynamic enhancement studies and the level of inflammatory activity. MRE is a suitable tool to differentiate between inflammatory and fibrotic lesions, making it useful to decide the appropriate management of each patient.

How to reduce the superior mesenteric vein bleeding risk during laparoscopic right hemicolectomy.

PURPOSE: The superior right colic vein (SRCV) has been proposed as the main cause of superior mesenteric vein bleeding by avulsion during laparoscopic right hemicolectomy. Our objective is to identify the main vessel causing transverse mesocolic tension during the extraction of the surgical specimen or extracorporeal anastomosis and to perform an anatomical description of the SRCV. METHODS: In this cadaveric study, we performed a simulation of right hemicolectomy and anatomical description of the surgical area of the gastrocolic trunk of Henle (SAGCTH), the gastrocolic trunk of Henle (GCTH), and SRCV. The length of the exteriorization of the anastomotic transverse colon (ATC) was measured before and after sectioning the vascular vessel causing the exteriorization tension. RESULTS: Five fresh cadavers and 12 formalin were dissected. In 100% of the specimens, the SRCV was present and drained in 95% into the GCTH and in 5% directly into the superior mesenteric vein (SMV). In 100% of the specimens, the SRCV caused the tension when extracting the ATC. The mean length of exteriorization of the ATC before and after SRCV section was 7.2 and 10.4 cm in formalin cadavers, meaning a 44% of increment in the length of exteriorization. In fresh cadavers, the mean length of exteriorization increased to 2.7 cm, meaning a 28% of the initial length of exteriorization. CONCLUSIONS: The SRCV is the main cause of tension in the extraction of the surgical specimen after right hemicolectomy. Its high tie increases the length of the ATC exteriorization, in about 3 cm, and could reduce the risk of SMV bleeding during laparoscopic right hemicolectomy and facilitate an extracorporeal anastomosis free of tension.

A Nomogram Combining Fecal Calprotectin Levels and Plasma Cytokine Profiles for Individual Prediction of Postoperative Crohn's Disease Recurrence.

BACKGROUND: The aims of this study were to characterize the immune response profile in patients with Crohn's disease (CD) and early postoperative recurrence (POR), to identify predictive biomarkers, and to develop a noninvasive predictive tool for individual estimation of POR risk. METHODS: Sixty-one patients who had undergone ileocolonic resection for CD were prospectively included and followed up for 24 months. Fecal calprotectin (FC), analytical parameters, and plasma cytokines were obtained before surgery and at various time points during postoperative follow-up. Morphological recurrence was assessed by ileocolonoscopy or magnetic resonance enterography within 6-12 months after surgery. Clinical activity was scored using the Harvey-Bradshaw Index. RESULTS: Twenty-seven patients (44.3%) had morphological recurrence during follow-up. Fecal calprotectin values were significantly associated with POR risk over time. The receiver operating characteristic curve for FC provided an area under the curve (AUC) of 0.88 (95% confidence interval, 0.75-0.96), and morphological recurrence was best predicted by FC ≥160 µg/g at 6 months after surgery (85% sensitivity, 70% specificity, 26% predictive positive value, 98% negative predictive value [NPV]). The plasma cytokine profile showed higher presurgery interleukin (IL)-13 plasma levels and higher IL-6 and interferon (IFN)-γ levels at 6 months after surgery in patients with POR compared with patients without recurrence. The combination of FC, IL-6, and IFN-γ values at 6 months gave an AUC of 0.90 for predicting an early recurrence. CONCLUSIONS: FC values <160 µg/g at 6 months have a high NPV to rule out early lesions. Combined values of FC, IL-6, and IFN-γ levels at 6 months postsurgery constitute a prognostic index with a high predictive capacity to assess the risk of early POR.

Fecal Calprotectin in Ileal Crohn's Disease: Relationship with Magnetic Resonance Enterography and a Pathology Score.

BACKGROUND: Magnetic resonance enterography (MRE) is an effective method of assessing small bowel Crohn's disease (CD). Fecal calprotectin (FC) correlates well with endoscopic disease activity. We aimed to evaluate the correlation between FC and disease activity according to MRE and surgical pathology in small bowel CD. METHODS: One hundred twenty consecutive patients with ileal CD who underwent MRE assessment were included. Clinical data, C-reactive protein and FC, radiological and histological variables were obtained. Clinical activity was evaluated by the Harvey-Bradshaw Index and FC by enzyme-linked immunosorbent assay. MRE activity was assessed by means of the Magnetic Resonance Index of Activity score. Chiorean's score was used to grade pathological inflammation in surgical specimens. RESULTS: Seventy-five patients (62.5%) were in clinical remission (Harvey-Bradshaw Index < 5) and 45 (37.5%) had active disease (Harvey-Bradshaw Index ≥ 5). The Magnetic Resonance Index of Activity score was significantly associated with FC levels (P < 0.01), with a moderate overall correlation (Spearman's r = 0.56, P < 0.001). FC reflected MRE inflammatory activity with an area under the receiver operating characteristic curve of 0.914 (confidence interval, 0.849-0.958; P < 0.001). A cutoff value of 166.50 µg/g had 90% sensitivity, 74% specificity, 89% positive predictive value, and 76% negative predictive value for diagnosis of inflammation. Twenty-eight of 120 patients were operated. Surgical pathology showed a good agreement with FC for moderate (P = 0.03) and severe (P = 0.01) Chiorean's index. No relationship was detected for C-reactive protein. CONCLUSIONS: FC correlates with the degree of MRE inflammatory activity and with surgical pathology damage in ileal CD. Thus, FC could be a surrogate marker of disease control used to select patients for MRE assessment and therapeutic adjustment.