Jeffrey A. Biller

Prospective Evaluation of MR Enterography as the Primary Imaging Modality for Pediatric Crohn Disease Assessment

OBJECTIVE The objectives of this study were prospective evaluation of MR enterographic accuracy for detecting Crohn disease imaging features in pediatric patients, compared with a CT reference standard, as well as determination of MR enterographic accuracy for detecting active bowel inflammation and fibrosis using a histologic reference standard. SUBJECTS AND METHODS The study group for this blinded prospective study included 21 pediatric subjects with known Crohn disease scheduled for clinical CT and histologic bowel sampling for symptomatic exacerbation. All subjects and their parents gave informed consent to also undergo MR enterography. CT and MR enterography examinations were independently reviewed by two radiologists and were scored for Crohn disease features. All bowel histology specimens were reviewed by a single pathologist for the presence of active mucosal inflammation and mural fibrosis, followed by correlation of imaging and histologic findings. RESULTS All 21 subjects underwent MR enterography and histologic sampling, 18 of whom also underwent CT. MR enterography had high sensitivity for detecting Crohn disease imaging features (e.g., bowel wall thickening, mesenteric inflammation, lymphadenopathy, fistula, and abscess) compared with CT, with individual sensitivity values ranging from 85.1% to 100%. Of a total of 53 abnormal bowel segments with correlation of MRI and histologic findings, MR enterography showed 86.7% accuracy (90.0% sensitivity and 82.6% specificity) for detecting active inflammation (p < 0.001). The accuracy of MR enterography for detecting mural fibrosis overall was 64.9%, compared with histology, but increased to 83.3% (p < 0.05) for detecting fibrosis without superimposed active inflammation. CONCLUSION MR enterography can substitute for CT as the first-line imaging modality in pediatric patients with Crohn disease, on the basis of its ability to detect intestinal pathologic abnormalities in both small and large bowel as well as extraintestinal disease manifestations. Additionally, MR enterography provides an accurate noninvasive assessment of Crohn disease activity and mural fibrosis and can aid in formulating treatment strategies for symptomatic patients and assessing therapy response.

Are endoscopic changes predictive of histologic esophagitis in children

Controversy exists regarding the value of gross mucosal changes of the esophagus at the time of endoscopy in predicting histologic esophagitis. Accordingly, we reviewed the records of 279 pediatric patients who underwent both an upper endoscopy and simultaneous grasp esophageal biopsy. Of those patients with no gross mucosal abnormalities, 30% had evidence of esophagitis on biopsy. Similarly, there was a poor association between the presence of endoscopic findings and histologic esophagitis. We conclude that gross esophageal mucosal changes are poor predictors of histologic esophagitis and that endoscopic evaluation alone is inadequate for children and adolescents in whom esophagitis is suspected. Esophageal biopsies should be obtained in all such patients, even when no gross mucosal abnormalities are found.

Long-term evaluation of esophageal and pulmonary function in patients with repaired esophageal atresia and tracheoesophageal fistula

Patients who have undergone repair of esophageal atresia and tracehoesophageal fistula as infants have been noted to have residual esophageal dysmotility and pulmonary dysfunction during their childhood years. However, limited information is available about the long-term follow-up of these patients. In this study we performed esophageal and pulmonary function studies on 12 adults who had required surgical repair of these defects in the first week of life. Most patients had symptoms of dysphagia and heartburn at time of evaluation. Pathologic gastroesophageal reflux was documented in 67% of patients and esophagitis was noted in 34%. All patients had esophageal motility abnormalities characterized by low-amplitude nonperistaltic waves throughout most of the esophagus. In addition, although most patients had no respiratory symptoms, mild restrictive lung volumes were noted in many patients. However, airflow obstruction and airway hyperreactivity were not present. These data demonstrate that clinical symptoms and abnormal esophageal manometry and pulmonary function persist well into the third and beginning of the fourth decade after repair of esophageal atresia and tracheoesophageal fistula in infancy.

Pyoderma gangrenosum occurring at multiple surgical incision sites

Ten weeks after subtotal colectomy and ileostomy for ulcerative colitis, a 16-yr-old girl developed wound drainage and back pain. Massive ulceration and skin separation occurred at the abdominal wound incision as well as at the incision sites of a previous central venous line. A diagnosis of pyoderma gangrenosum was made. High-dose steroid treatment induced prompt healing of the abdominal wound as well as the catheter sites. Pyoderma gangrenosum has rarely been seen in surgical wounds. To our knowledge, this is the first reported case of pyoderma gangrenosum occurring simultaneously in multiple surgical incision sites in a patient with ulcerative colitis.

Use of a 3T3 cell growth factor assay for the delineation and characterization of humoral trophic factors involved in intestinal adaptation in the rat

Indirect evidence has suggested that circulating trophic factors are involved in intestinal adaptation. A 3T3 fibroblast cell culture system was used to more directly delineate the presence of such factors. Rats were divided into four groups: C-unop, those undergoing no surgery; S, those in which a dorsal slit was made; C-op, those in which the peritoneum was incised; and R, those undergoing 80% intestinal resection. At the time of death at 24 h, 1 wk, and 2 wk postoperative, stimulation of DNA synthesis in the 3T3 cells was noted after incubation with platelet-free plasma from the C-op and R groups, and simultaneously an increase in ileal DNA specific activity occurred. Characterization of the plasma fraction with growth factor activity revealed it to have a molecular weight of greater than 6000 but less than 14,000. The factors were resistant to reduction with dithiothreitol, and were partially inactivated by heating to 60 degrees C. The use of a 3T3 cell growth factor assay system now makes it possible to further characterize circulating factors involved in intestinal adaptation.

Abdominal abscesses in adolescents with Crohn's disease.

Little information is available about the development of abdominal abscesses in adolescents with Crohns disease. We report the clinical presentation of five adolescents with Crohns disease who developed this complication. The mean time from diagnosis until development of an abdominal abscess was 1.7 years. The admitting diagnosis was an acute abdomen in two patients and recurrent Crohns disease in the other three. No features of the clinical presentation or laboratory data distinguished this group from other adolescents with Crohns disease. The use of ultrasound and CT scanning was helpful in making this diagnosis preoperatively. Those patients with active Crohns disease who do not respond promptly to medical therapy should be evaluated for the development of this complication.

Resection of acquired mucosal web in Crohn disease.

I ntestinal webs are an uncommon cause of abdominal pain especially in children. We present a patient with a symptomatic colonic web, which developed during medical and surgical management of his Crohn disease (CD). Endoscopic resection was successful, avoiding the need for surgical correction. A 16-year-old boy with ileocolonic CD presented with left upper quadrant abdominal pain. His ileocolonic CD had been diagnosed 15 months before and was managed with mesalamine and a course of prednisone. His CD course had been complicated by a large (6.3 cm 1.8 cm) right lower quadrant abscess adjacent to the distal ileum requiring interventional radiology–guided drainage and 6 weeks of intravenous antibiotics. An ileocecectomy was performed, but during the procedure, the interventional radiology drain was found to be adherent to the wall of the transverse colon. The drain was dissected off of the colon, and a small wedge resection (1.8 cm in largest dimension) was performed with oversewing of the colonic margins. Histologic analysis of the resected wedge showed mucosal ulceration, subserosal abscesses, and granulation tissue. Following this repair, the ileocecectomy was completed (including resection of 36 cm of distal ileum). Ten months following ileocecectomy, the patient complained of intermittent left upper quadrant abdominal pain. His physical examination was notable only for mild, diffuse abdominal tenderness, and the patient had a normal complete blood cell count and erythrocyte sedimentation rate. Colonoscopy was performed, and an intraluminal web was found in the distal transverse colon at the wedge resection site (Fig. 1). The web contained 2 distinct openings, each permitting colonoscope passage into the proximal colon and allowing for completion of the colonoscopy to the neoterminal ileum (without evidence of fistulae). Mucosa from the proximal colon was observed prolapsing through the web. Biopsy from this site showed mild, active inflammation. Following completion of the colonoscopy, a barium enema was obtained that showed a normal-diameter colon (Fig. 2). It was concluded that the mucosal web was causing the patient’s symptoms due to obstruction

Characterisation of humoral trophic factors involved in intestinal adaptation using a 3T3 cell growth factor assay.

Indirect evidence has suggested that circulating trophic factor(s) are involved in intestinal adaptation. A 3T3 fibroblast cell culture system was used to more directly delineate the presence of such factors. Rats were divided into four groups; C-unop, those undergoing no surgery, S, those in which a dorsal slit was made; C-op, those in which the peritoneum was incised; and R, those undergoing 80% intestinal resection. At the time of death at 24 hours, one week and two weeks postoperative, stimulation of DNA synthesis in the 3T3 cells was noted after incubation with platelet free plasma from the C-op and R groups, and simultaneously an increase in ileal DNA specific activity occurred. Characterisation of the plasma fraction with growth factor activity revealed it to have a MW of greater than 6,000 and less than 14,000 d. The factor(s) was resistant to reduction with DTT, and was partially inactivated by heating to 60 degrees C. The use of 3T3 cell growth factor assay system allows further characterisation of circulating factors involved in intestinal adaptation.