The accuracy of preoperative imaging in measuring the length of the ileocolic segment affected by Crohn's disease: a prospective cohort study

Preoperative Magnetic Resonance Enterography to Predict Pathological Specimen Length in Crohn's Disease

BACKGROUND

The European Crohn's and Colitis Organization guidelines have highlighted the importance of the preoperative evaluation of the affected segment length in patients with ileocolic Crohn's disease to determine the best surgical approach.

OBJECTIVE

This study aimed to evaluate the accuracy of preoperative magnetic resonance enterography in assessing the length of the affected segment in patients with ileocolic Crohn's disease.

DESIGN

This observational study was conducted with a prospectively maintained database and retrospective analysis.

SETTINGS

This study was conducted in a tertiary center.

PATIENTS

This study included consecutive patients undergoing ileocolic resection for Crohn's disease between August 2014 and June 2020. All patients underwent a preoperative magnetic resonance enterography.

MAIN OUTCOME MEASURES

The correlation between the length measured on magnetic resonance enterography and pathological examination was evaluated.

RESULTS

A total of 96 patients were included. The median time between magnetic resonance enterography and surgery was 65.5 (3-331) days. The length of the affected segment on magnetic resonance enterography was correlated with the length assessed on pathological evaluation ( R = 0.48, p < 0.001). No correlation was found between the 2 measurements when imaging was performed >6 months before surgery ( R = 0.14, p = 0.62). The presence of an abscess underestimated the length affected by Crohn's disease on imaging compared to pathology, whereas the presence of a fistula was associated with magnetic resonance enterography overestimation of the length of the affected segment.

LIMITATIONS

Limitations included single-center study and retrospective analysis.

CONCLUSION

In Crohn's disease, preoperative magnetic resonance enterography is a highly reliable tool for predicting the length of the affected segment compared to pathology examination in the absence of an abscess or fistula. See Video Abstract at http://links.lww.com/DCR/C26 .

ENTEROGRAFA POR RESONANCIA MAGNTICA PREOPERATORIA PARA PREDECIR LA LONGITUD DE MUESTRAS PATOLGICAS EN LA ENFERMEDAD DE CROHN

ANTECEDENTES:Las guías de la Organización Europea de Crohn y Colitis han resaltado la importancia de la evaluación preoperatoria de la longitud del segmento afectado para determinar el mejor abordaje quirúrgico.OBJETIVO:Evaluamos la precisión de la enterografía por resonancia magnética preoperatoria para evaluar la longitud del segmento afectado en pacientes con enfermedad de Crohn ileocólica.DISEÑO:Realizamos un estudio observacional con una base de datos mantenida prospectivamente y un análisis retrospectivo.CONFIGURACIÓN:Este estudio se realizó en un centro terciario.PACIENTES:Se incluyeron pacientes consecutivos sometidos a resección ileocólica por enfermedad de Crohn entre Agosto de 2014 y Junio de 2020. A todos los pacientes se les realizó una enterografía por resonancia magnética preoperatoria.PRINCIPALES MEDIDAS DE RESULTADO:Se evaluó la correlación entre la longitud medida en la enterografía por resonancia magnética y el examen patológico.RESULTADOS:Se incluyeron un total de 96 pacientes. El tiempo mediano entre la enterografía por resonancia magnética y la cirugía fue de 65,5 (3-331) días. La longitud del segmento afectado en la enterografía por resonancia magnética se correlacionó con la longitud evaluada en la evaluación patológica ( R = 0,48, p < 0,001). No hubo correlación entre las 2 mediciones cuando las imágenes se realizaron más de 6 meses antes de la cirugía ( R = 0,14, p = 0,62). La presencia de un absceso subestimó la longitud afectada por la enfermedad de Crohn en las imágenes en comparación con la patología, mientras que la presencia de una fístula se asoció con una sobrestimación de la longitud del segmento afectado por enterografía por resonancia magnética.LIMITACIONES:Las limitaciones incluyeron un estudio de un solo centro y un análisis retrospectivo.CONCLUSIÓNES:En la enfermedad de Crohn, la enterografía por resonancia magnética preoperatoria es una herramienta altamente confiable para predecir la longitud del segmento afectado en comparación con el examen de patología, en ausencia de absceso o fístula. Consulte el Video Resumen en http://links.lww.com/DCR/C26 . (Traducción-Dr. Yesenia Rojas-Khalil ).

The Challenge of Small Intestine Length Measurement: A Systematic Review of Imaging Techniques

BACKGROUND

Short bowel syndrome is the most common cause of intestinal failure, with morbidity and mortality linked to remanent small intestine length. There is no current standard for noninvasive bowel length measurement.

MATERIALS AND METHODS

The literature was systematically searched for articles describing measurements of small intestine length from radiographic studies. Inclusion required reporting intestinal length as an outcome and use of diagnostic imaging for length assessment compared to a ground truth. Two reviewers independently screened studies for inclusion, extracted data, and assessed study quality.

RESULTS

Eleven studies met the inclusion criteria and reported small intestinal length measurement using four imaging modalities: barium follow-through, ultrasound, computed tomography, and magnetic resonance. Five barium follow-through studies reported variable correlations with intraoperative measurements (r = 0.43-0.93); most (3/5) reported underestimation of length. US studies (n = 2) did not correlate with ground truths. Two computed tomography studies reported moderate-to-strong correlations with pathologic (r = 0.76) and intraoperative measurements (r = 0.99). Five studies of magnetic resonance showed moderate-to-strong correlations with intraoperative or postmortem measurements (r = 0.70-0.90). Vascular imaging software was used in two studies, and a segmentation algorithm was used for measurements in one.

CONCLUSIONS

Noninvasive measurement of small intestine length is challenging. Three-dimensional imaging modalities reduce the risk of length underestimation, which is common with two-dimensional techniques. However, they also require longer times to perform length measurements. Automated segmentation has been trialed for magnetic resonance enterography, but this method does not translate directly to standard diagnostic imaging. While three-dimensional images are most accurate for length measurement, they are limited in their ability to measure intestinal dysmotility, which is an important functional measure in patients with intestinal failure. Future work should validate automated segmentation and measurement software using standard diagnostic imaging protocols.

Intraoperative inspection alone is a reliable guide to the choice of surgical procedure for enteroenteric fistulas in Crohn's disease

Background/Aims

Resection of the diseased segment and suture of the victim segment is recommended for enteroenteric fistula in Crohn's disease (CD). The main difficulty in this procedure remains reliable diagnosis of the victim segment, especially for fistulas found intraoperatively and inaccessible on endoscopic examination. We aimed to explore whether intraoperative inspection alone is reliable.

Methods

Patients undergoing conservative surgery between 2011 and 2016 for enteroenteric fistulas complicating CD were identified from a prospectively maintained database. Patients were divided according to whether the victim segment was evaluated by preoperative endoscopy + intraoperative inspection (PI group) or by intraoperative inspection alone (I group). Outcomes were compared.

Results

Of 65 patients eligible for the study, 37 were in in the PI group and 28 were in the I group. The baseline characteristics were similar between the groups, except for the rate of emergency surgery (0/37 in PI group vs. 5/28 in I group, P=0.012). Fistulas involved more small intestines (4/37 in PI group vs. 15/28 in I group, P<0.001) and fewer sigmoid colons (17/37 in PI group vs. 4/28 in I group, P=0.008) in I group due to accessibility with endoscopy. No difference was found in postoperative complications, stoma rates, postoperative recurrence, or disease at the repair site between the 2 groups (P>0.05).

Conclusions

For fistulas found intraoperatively and inaccessible on endoscopic examination, intraoperative inspection was a reliable guide when choosing between en bloc resection and a conservative procedure.