In vitro quantification of stent-graft behaviour during chimney thoracic endovascular aortic repair.

OBJECTIVE: To quantify dynamic gutter phenomena and endograft deformations during double chimney thoracic endovascular aortic repair (ch-TEVAR) in a physiological model of the thoracic aorta subjected to pulsatile haemodynamic conditions. METHODS: Two in vitro procedures revascularizing the brachiocephalic trunk and left common carotid artery were performed representing both balloon-expandable (BE, Ankura-BeGraft) and self-expandable (SE, Ankura-Viabahn) double ch-TEVAR configurations. Retrospectively gated computed tomography (CT) was used to evaluate endograft behaviour. Device interactions were characterised according to gutter volume, gutter surface deviation, and endograft deformation (D-ratio) at end-diastolic and peak-systolic aortic pressure. RESULTS: Use of BE chimney grafts resulted in three times total gutter volume compared to SE chimney grafts. Gutter volumes were observed to vary dynamically between the end-diastolic and peak-systolic phases of the cardiac cycle, with the most substantial change associated with the BE configuration. Chimney graft deformations were dependent on device type, with SE devices exhibiting up to twice the deformation as BE devices. When adjacent, SE chimney grafts were observed to support each other, and thus tended towards a more consistently circular shape. CONCLUSION: Gutter and chimney graft behaviour were dependent on device type, and exhibited both spatial and temporal variability. This study emphasises notable differences between BE and SE double ch-TEVAR configurations which should be considered when evaluating risk of endoleak. The findings reported here also support the use of gated CT to better identify device-related complications with ch-TEVAR, and can be used in the design of next generation devices.

Successful Primary PCI in Stanford Type A Aortic Dissection Complicated by Inferior ST-Elevation Myocardial Infarction: A Case in a Facility with No Surgical Backup.

Mortality of type A aortic dissection (TAAD) complicated with coronary malperfusion syndrome is very high even when emergency surgery is performed. Several reports suggested that primary percutaneous coronary intervention (PPCI) followed by immediate corrective surgery may reduce mortality. In many countries, immediate transfer to an aortic surgery center may not be possible. We report a case of TAAD complicated by coronary malperfusion successfully treated with PPCI followed by elective corrective surgery. A 48-year-old man was referred to emergency department with acute inferior ST-elevation myocardial infarction (STEMI) and underwent PPCI. During the procedure, we realized that the cause of STEMI was TAAD. We decided to continue because the patient experienced seizures and bradycardia. Subsequently, echocardiography and computed tomography confirmed the dissection. The patient was discharged and referred to the National Cardiovascular Center where he underwent successful elective surgery. In this patient, immediate revascularization was lifesaving and served as a bridging procedure before surgical correction.

Diagnosis and Management of Acute Lower Gastrointestinal Bleeding: Guidelines From the British Society of Gastroenterology

This is the first UK national guideline to concentrate on acute lower gastrointestinal bleeding (LGIB) and has been commissioned by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG). The Guidelines Development Group consisted of representatives from the BSG Endoscopy Committee, the Association of Coloproctology of Great Britain and Ireland, the British Society of Interventional Radiology, the Royal College of Radiologists, NHS Blood and Transplant and a patient representative. A systematic search of the literature was undertaken and the quality of evidence and grading of recommendations appraised according to the GRADE(Grading of Recommendations Assessment, Development and Evaluation) methodology. These guidelines focus on the diagnosis and management of acute LGIB in adults, including methods of risk assessment and interventions to diagnose and treat bleeding (colonoscopy, computed tomography, mesenteric angiography, endoscopic therapy, embolisation and surgery). Recommendations are included on the management of patients who develop LGIB while receiving anticoagulants (including direct oral anticoagulants) or antiplatelet drugs. The appropriate use of blood transfusion is also discussed, including haemoglobin triggers and targets.