Infected Urachal Cyst Mimicking Urachal Carcinoma: A Rare Cause of Lower Abdominal Tenderness.

Teaching Point: Infected urachal cysts are a rare cause of abdominal complaints and can be accurately diagnosed by abdominal ultrasound and computed tomography (CT).

Right-sided aortic arch with Kommerell's diverticulum: a case report of a rare cause of type B dissection.

Background: A right-sided aortic arch (RAArch) is present in approximately 0.1% of the population. A Kommerell's diverticulum (KD), a remnant of the dorsal aortic arch usually refers to an aneurysmal aortic enlargement at the origin of an aberrant left subclavian artery (ALSA) and is associated with an increased risk of aortic dissection. Case summary: A 59-year-old female smoker with a history of hypertension and hypercholesterolaemia presented with a 24-hour history of sudden-onset and severe stabbing chest pain radiating to the interscapular region. Physical examination was normal except for bilateral basal crepitations. Computed tomography angiography (CTA) showed a type B aortic dissection in a RAArch with an ALSA arising from KD with a peri-aortic haematoma and haemothorax without any active contrast extravasation. After medical stabilization, a semi-urgent hybrid repair was performed with a right carotid-subclavian bypass, thoracic endovascular aortic repair (TEVAR), a plug in the left subclavian artery, and left carotid-subclavian bypass due to severe ischaemia of the left arm. The postoperative CTA showed patent bypasses, aortic remodelling, and a minimal type IIa endoleak at the level of the ALSA. Discussion: In patients with a type B dissection and KD, hybrid repair including TEVAR is feasible after careful pre-operative assessment of the patient's unique anatomy and may reduce post-surgical morbidity and mortality compared to open surgery. Prophylactic repair may be considered in patients with an asymptomatic RAArch and KD.

Selective Transport of Protein-Bound Uremic Toxins in Erythrocytes.

To better understand the kinetics of protein-bound uremic toxins (PBUTs) during hemodialysis (HD), we investigated the distribution of hippuric acid (HA), indole-3-acetic acid (IAA), indoxyl sulfate (IS), and p-cresyl sulfate (pCS) in erythrocytes of HD patients. Their transport across the erythrocyte membrane was explored in the absence of plasma proteins in vitro in a series of loading and unloading experiments of erythrocytes from healthy subjects and HD patients, respectively. Furthermore, the impact of three inhibitors of active transport proteins in erythrocytes was studied. The four PBUTs accumulated in erythrocytes from HD patients. From loading and unloading experiments, it was found that (i) the rate of transport was dependent on the studied PBUT and increased in the following sequence: HA < IS < pCS < IAA and (ii) the solute partition of intra- to extra-cellular concentrations was uneven at equilibrium. Finally, inhibiting especially Band 3 proteins affected the transport of HA (both in loading and unloading), and of IS and pCS (loading). By exploring erythrocyte transmembrane transport of PBUTs, their kinetics can be better understood, and new strategies to improve their dialytic removal can be developed.