Once in a Bile - the Incidence of Bile Reflux Post-Bariatric Surgery.

PURPOSE: Excellent metabolic improvement following one anastomosis gastric bypass (OAGB) remains compromised by the risk of esophageal bile reflux and theoretical carcinogenic potential. No 'gold standard' investigation exists for esophageal bile reflux, with diverse methods employed in the few studies evaluating it post-obesity surgery. As such, data on the incidence and severity of esophageal bile reflux is limited, with comparative studies lacking. This study aims to use specifically tailored biliary scintigraphy and upper gastrointestinal endoscopy protocols to evaluate esophageal bile reflux after OAGB, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). METHODS: Fifty-eight participants underwent OAGB (20), SG (15) or RYGB (23) between November 2018 and July 2020. Pre-operative reflux symptom assessment and gastroscopy were performed and repeated post-operatively at 6 months along with biliary scintigraphy. RESULTS: Gastric reflux of bile was identified by biliary scintigraphy in 14 OAGB (70%), one RYGB (5%) and four SG participants (31%), with a mean of 2.9% (SD 1.5) reflux (% of total radioactivity). One participant (OAGB) demonstrated esophageal bile reflux. De novo macro- or microscopic gastroesophagitis occurred in 11 OAGB (58%), 8 SG (57%) and 7 RYGB (30%) participants. Thirteen participants had worsened reflux symptoms post-operatively (OAGB, 4; SG, 7; RYGB, 2). Scintigraphic esophageal bile reflux bore no statistical association with de novo gastroesophagitis or reflux symptoms. CONCLUSION: Despite high incidence of gastric bile reflux post-OAGB, esophageal bile reflux is rare. With scarce literature of tumour development post-OAGB, frequent low-volume gastric bile reflux likely bears little clinical consequence; however, longer-term studies are needed. CLINICAL TRIAL REGISTRY: Australian New Zealand Clinical Trials Registry number ACTRN12618000806268.

AFM/TIRF force clamp measurements of neurosecretory vesicle tethers reveal characteristic unfolding steps.

Although several proteins have been implicated in secretory vesicle tethering, the identity and mechanical properties of the components forming the physical vesicle-plasma membrane link remain unknown. Here we present the first experimental measurements of nanomechanical properties of secretory vesicle-plasma membrane tethers using combined AFM force clamp and TIRF microscopy on membrane sheets from PC12 cells expressing the vesicle marker ANF-eGFP. Application of pulling forces generated tether extensions composed of multiple steps with variable length. The frequency of short (<10 nm) tether extension events was markedly higher when a fluorescent vesicle was present at the cantilever tip and increased in the presence of GTPγS, indicating that these events reflect specifically the properties of vesicle-plasma membrane tethers. The magnitude of the short tether extension events is consistent with extension lengths expected from progressive unfolding of individual helices of the exocyst complex, supporting its direct role in forming the physical vesicle-plasma membrane link.

Autologous osteochondral transplantation for osteochondral lesions of the talus in an athletic population.

PURPOSE: To assess clinical outcomes and return to sport in an athletic population treated with autologous osteochondral transplantation (AOT) for osteochondral lesions of the talus. METHODS: A total of 36 patients were included in this retrospective study including 21 professional athletes and 15 amateur athletes who participated in regular moderate- or high-impact athletic activity. All patients underwent autologous osteochondral transplantation of the talus under the care of a single surgeon. At a mean follow-up of 5.9 years, patients were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) scoring system. All patients also received pre-operative MRI with the follow-up MRI performed at 1 year and underwent assessment of return to athletic activity. RESULTS: The overall AOFAS score improved from 65.5 (SD ± 11.1) to 89.4 (SD ± 14.4) (p = 0.01). At a final follow-up, 90% of professional athletes (19 of 21) were still competing in athletic activity or still able to participate in unrestricted activity. Of the recreational athletes, 87% (13 of 15) had full return to pre-injury activity levels, while two (13%) returned to activity with restrictions or reduced intensity. MRI showed cystic change in 33% of patients post-operatively; however, this did not appear to affect outcomes (n.s.). Donor site symptoms were seen in 11% of the cohort at final follow-up, despite high function at donor knee. CONCLUSION: The results of our study indicate that AOT procedure is able to achieve good outcomes in an athletic population at a midterm follow-up. LEVEL OF EVIDENCE: Retrospective case series, Level IV.