Ballard, David H.

Abstract Background and Aims Perianal fistuliing Crohn’s disease [PFCD] is an aggressive phenotype of Crohn’s disease defined by frequent relapses and disabling symptoms. A novel consensus classification system was recently outlined by the TOpCLASS consortium, which seeks to unify disease severity with patient-centred goals but has not yet been validated. We aimed to apply this to a real-world cohort and to identify factors that predict transition between classes over time. Methods We identified all patients with PFCD and at least one baseline and one follow-up pelvic MRI [pMRI]. TOpCLASS classification, disease characteristics, and imaging indices were collected retrospectively at time periods corresponding with respective MRIs. Results We identified 100 patients with PFCD, of whom 96 were assigned TOpCLASS Classes 1–2c at baseline. Most patients [78.1%] started in Class 2b, but changes in classification were observed in 52.1% of all patients. Male sex [72.0%, 46.6%, 40.0%, p = 0.03] and prior perianal surgery [52.0% vs 44.6% vs 40.0%, p = 0.02] were more frequently observed in those with improved class compared to unchanged and worsened class. Baseline pMRI indices were not associated with changes in classification; however, greater improvements in mVAI, MODIFI-CD, and PEMPAC were seen among those who improved. Linear mixed effect modelling identified only male sex [-0.31, 95% CI -0.60 to -0.02] with improvement in class. Conclusion The TOpCLASS classification highlights the dynamic nature of PFCD over time. However, our ability to predict transitions between classes remains limited and requires prospective assessment. Improvement in MRI index scores over time was associated with a transition to lower TOpCLASS classification.

Fournier gangrene (FG) is a genitourinary necrotizing fasciitis that can be lethal if not promptly diagnosed and surgically debrided. The diagnosis is often made by physical examination paired with an appropriate clinical suspicion and supporting laboratory values. Imaging, particularly computed tomography (CT), plays a role in delineating involved fascial planes for operative debridement and occasionally in diagnosing FG. Less commonly, the imaging manifestations of FG may also be seen on ultrasound, radiographs, and magnetic resonance imaging. With the ubiquitous use and availability of CT, radiologists have a growing role in recognizing FG. This can be challenging in the absence of fascial gas, but a CT scoring system for necrotizing fasciitis can be helpful in making the diagnosis. Recent series suggest that this predominantly male disease has a rising incidence in women. Women with FG are more likely to be morbidly obese and have vulvar or labial involvement compared to men. Imaging mimics include ulcerative and necrotic tumors, traumatic or iatrogenic fascial gas, and vaginitis emphysematosa. The purpose of this pictorial review is to illustrate the imaging manifestations of FG and its mimics, with emphases on necrotizing fasciitis CT scoring systems and FG in women.

Three-dimensional (3D) printing is an additive manufacturing method that holds great potential in a variety of future patient-specific medical technologies. This project validated a novel crosslinked polyvinyl alcohol (XL-PVA) 3D printed stent infused with collagen, human placental mesenchymal stem cells (PMSCs), and cholangiocytes. The biofabrication method in the present study examined 3D printing and collagen injection molding for rapid prototyping of customized living biliary stents with clinical applications in the setting of malignant and benign bile duct obstructions. XL-PVA stents showed hydrophilic swelling and addition of radiocontrast to the stent matrix improved radiographic opacity. Collagen loaded with PMSCs contracted tightly around hydrophilic stents and dense choloangiocyte coatings were verified through histology and fluorescence microscopy. It is anticipated that design elements used in these stents may enable appropriate stent placement, provide protection of the stent-stem cell matrix against bile constituents, and potentially limit biofilm development. Overall, this approach may allow physicians to create personalized bio-integrating stents for use in biliary procedures and lays a foundation for new patient-specific stent fabrication techniques.