Peter Riley

Long-term results of stent-graft placement to treat central venous stenosis and occlusion in hemodialysis patients with arteriovenous fistulas.

PURPOSE To determine the effectiveness of stent-grafts for the treatment of central venous disease in hemodialysis patients with functioning arteriovenous (AV) fistulas. MATERIALS AND METHODS Between October 2004 and March 2010, 42 VIABAHN stent-grafts were deployed in central veins of 30 patients (16 men, 14 women; mean age 60 y) with functioning AV fistulas and central venous disease that did not respond to percutaneous transluminal angioplasty (PTA). Eighteen patients had central vein stenosis and 12 had occlusion. Previous PTA and/or bare metal stent placement had been performed in 23 patients (77%). Surveillance was carried out at 3, 6, 9, 12, 18, and 24 months with diagnostic fistulography. The mean follow-up was 705 days (range, 66-1,645 d). Statistical analysis included Kaplan-Meier and log-rank studies. RESULTS Technical success rate was 100%. Primary patency rates were 97%, 81%, 67%, and 45% at 3, 6, 12, and 24 months, respectively. Primary assisted patency rates were 100%, 100%, 80%, and 75% at 3, 6, 12, and 24 months, respectively. Patients without previous procedures had significantly shorter times to repeat intervention (P = .018) than those who had undergone PTA or bare metal stent placement previously. Patients with occlusive lesions had a significantly shorter primary patency interval (P = .05) than patients with stenoses. Occluded veins were more likely to require further stent-grafts (P = .02). Twelve patients required further stent-grafts to maintain patency. There was one minor complication. CONCLUSIONS Stent-graft placement to treat central venous disease in hemodialysis patients with autogenous AV fistulas is safe and effective if PTA fails to maintain luminal patency.

Reproducibility of thoracic aortic diameter measurement using computed tomographic scans.

OBJECTIVES Decisions to recommend elective surgical repair of thoracic aortic aneurysms (TAA) may be based on size or expansion rate, which are used as indices of the risk of rupture. Measurement error may thus affect clinical decision-making. In order to evaluate the reproducibility of aortic diameter measurements of TAA, we assessed departmental inter- and intra-observer variability of measurement of pre-selected computed tomographic scan images of aneurysmal segments of the thoracic aorta. METHODS We compared measurements of minimum aortic diameter made by four observers in 50 pre-selected scans and at different times by two observers using a calliper method and a measurement tool within the scan. Differences in measured dimension were analysed using Wilcoxons signed ranks test and the repeatability assessed using the method of Bland and Altman. RESULTS There were no significant inter-observer differences among three observers but there were significant differences between another observer and two other observers (P < 0.05). No significant intra-observer differences existed. The best intra-observer repeatability was 2.25 while the worst inter-observer repeatability was 4.37. The mean and maximum difference in measurement were +/-0.88 mm and +/-8.0 mm, respectively. Variability of measurement increased with aortic diameter. CONCLUSIONS Calliper measurement of TAA is an acceptable measurement method for surveillance of TAA but appears most accurate with a single observer. Increasing error is seen with increasing diameter which may compound error in estimation of expansion rate. Standardisation of technique is advisable for multiple observers and aortic units should adopt quality assurance protocols to minimise error.

Near-infrared spectroscopy: an important monitoring tool during hybrid aortic arch replacement.

Near-infrared spectroscopy can be helpful for monitoring the adequacy of cerebral perfusion during cardiovascular surgery. We report changes seen in regional oxygen saturation due to intraoperative thrombosis of the left common carotid artery graft during hybrid aortic arch replacement for traumatic aortic injury.

Emergency endovascular stent graft repair of aorto-bronchial fistulas postcoarctation repair.

Abstract  Cardiovascular complications following coarctation repair include aorto bronchial fistulas (ABF) which if untreated are invariably fatal. Reoperative surgery is associated with considerable mortality and morbidity. Endovascular stent aortoplasty provides a relatively new and viable alternative. Two cases of ABF post coarctation repair that presented with life threatening haemoptysis are discussed. Endovascular repair appears safe and feasible in an emergency and may become the preferred treatment modality in such cases.

Failure to exclude a saccular arch aneurysm during hybrid repair: arch replacement without cerebral circulatory arrest.

Thoracic endovascular aortic reconstruction (TEVAR) is increasingly used in the management of descending aortic pathology including aneurysms, dissections and transaction. When treating aortic arch pathology, hybrid procedures have been devised, in which major supra-aortic arteries are translocated using a variety of techniques. Such hybrid procedures offer an attractive alternative to open arch procedures in frail elderly patients in whom the risks of open repair are considerable. We describe a surgical bail-out procedure which was used during a hybrid aortic arch replacement when endovascular aneurysm exclusion could not be achieved.

Imaging of thoracic trauma

The purpose of this article is to demonstrate the commonly encountered findings in all types of thoracic trauma. It is not intended to be a systematic review of the literature, but will discuss and illustrate the differing imaging techniques which are used to diagnose common traumatic injuries in the thorax. Interventional radiology-based therapeutic interventions will be demonstrated.

Transposition of Arch Vessels and Endovascular Stenting of Saccular Aneurysm of Distal Arch—A Case Report

Abstract  Endovascular repair of thoracic aneurysms has emerged as an attractive alternative especially in high‐risk patients. However, the aortic curvature and potential coverage of the epiaortic vessels limit the use of stent‐grafts in aneurysms located in the aortic arch. We report a case with a saccular aneurysm in the distal arch and proximal descending aorta, where we have transposed the epiaortic vessels to gain a longer proximal neck in the aortic arch to safely deploy an endovascular stent.