Editor's choice--Angulation of the C-arm during complex endovascular aortic procedures increases radiation exposure to the head.

OBJECTIVES/BACKGROUND: The increased complexity of endovascular aortic repair necessitates longer procedural time and higher radiation exposure to the operator, particularly to exposed body parts. The aims were to measure directly exposure to radiation of the bodies and heads of the operating team during endovascular repair of thoracoabdominal aortic aneurysms (TAAA), and to identify factors that may increase exposure. METHODS: This was a single-centre prospective study. Between October 2013 and July 2014, consecutive elective branched and fenestrated TAAA repairs performed in a hybrid operating room were studied. Electronic dosimeters were used to measure directly radiation exposure to the primary (PO) and assistant (AO) operator in three different areas (under-lead, over-lead, and head). Fluoroscopy and digital subtraction angiography (DSA) acquisition times, C-arm angulation, and PO/AO height were recorded. RESULTS: Seventeen cases were analysed (Crawford II-IV), with a median operating time of 280 minutes (interquartile range 200-330 minutes). Median age was 76 years (range 71-81 years); median body mass index was 28 kg/m(2) (25-32 kg/m(2)). Stent-grafts incorporated branches only, fenestrations only, or a mixture of branches and fenestrations. A total of 21 branches and 38 fenestrations were cannulated and stented. Head dose was significantly higher in the PO compared with the AO (median 54 µSv [range 24-130 µSv] vs. 15 µSv [range 7-43 µSv], respectively; p = .022), as was over-lead body dose (median 80 µSv [range 37-163 µSv] vs. 32 µSv [range 6-48 µSv], respectively; p = .003). Corresponding under-lead doses were similar between operators (median 4 µSv [range 1-17 µSv] vs. 1 µSv [range 1-3 µSv], respectively; p = .222). Primary operator height, DSA acquisition time in left anterior oblique (LAO) position, and degrees of LAO angulation were independent predictors of PO head dose (p < .05). CONCLUSIONS: The head is an unprotected area receiving a significant radiation dose during complex endovascular aortic repair. The deleterious effects of exposure to this area are not fully understood. Vascular interventionalists should be cognisant of head exposure increasing with C-arm angulation, and limit this manoeuvre.

Identification of patient safety improvement targets in successful vascular and endovascular procedures: analysis of 251 hours of complex arterial surgery.

OBJECTIVES: To investigate failures in patient safety for patients undergoing vascular and endovascular procedures to guide future quality and safety interventions. DESIGN: Single centre prospective observational study. METHODS: 66 procedures (17 thoracoabdominal and 23 abdominal aortic aneurysms, 4 carotid and 22 limb procedures) were observed prospectively over a 9-month period (251 h operating time) by two trained observers. Event logs were recorded for each procedure. Two blinded experts identified and independently categorised failures into 22 types (using a validated category tool) and severity (5-point scale). Data are expressed as median (range). Statistical analysis was performed using Mann-Whitney U, Kruskal-Wallis and Spearman's Rank tests. RESULTS: 1145 failures were identified with good inter-assessor reliability (Cronbach's alpha 0.844). The commonest failure types related to equipment (including unavailability, configuration and other failures) (269/1145 [23.5%]) and communication (240/1145 [21.0%]). A comparatively lower number of technical and psychomotor failures were identified (103 [9.0%]). The number of failures correlated with procedure duration (rho = 0.695, p < 0.001) but not anatomical site of the procedure or pathology of the disease process. Failure rate was higher in patients undergoing combined surgical/endovascular procedures compared to open surgery (median 5.7/h [IQR 4.2-8.1] vs 3.0/h [2.5-3.5]; p < 0.001). The severity of failures was similar (1.5/5 [1-2] vs 1/5 [1-2] respectively; p = 0.095). For combined procedures, failure rates were significantly higher during the endovascular phase (9.6/h [7.5-13.7]) compared to the non-endovascular phase (3.0/h [1.0-5.0]; p < 0.001). CONCLUSIONS: Failures in patient safety are common during complex arterial procedures. Few failures were severe, although minor failures during critical stages and accumulation of multiple minor failures may potentially be important. Failures occurred especially during the endovascular phase and were often related to equipment or communication aspects. Interventions to improve procedural safety and quality of care should primarily target these specific areas.

Optimising pre- and postoperative imaging for thoracic aortic pathology.

Thoracic aortic pathology carries significant morbidity and mortality, which requires prompt and accurate clinical and radiological evaluation. Advances in imaging technologies have improved our knowledge of the mechanisms of growth and rupture and our understanding of endovascular repair. Computed tomography has become a crucial component in this process, replacing catheter-based angiography as the most commonly used pre- and postoperative imaging modality for the thoracic aorta. Functional imaging methods such as magnetic resonance and echocardiography are evolving and are able to provide the clinically relevant anatomic, haemodynamic and biomechanical information that is necessary for accurate diagnosis, risk stratification and selection of the appropriate treatment for an individual patient. The availability of advanced image acquisition expertise and equipment is spreading to a growing number of institutions worldwide and will greatly enhance existing imaging strategies for patients with thoracic aortic pathology.

Uncomplicated type B dissections: which patients should be treated? Lessons learned from the recent literature.

The management of type B aortic dissection is complex and decision-making is often based on physician experience and subjective clinical judgment. Thoracic endovascular aortic repair is considered first-line therapy for complicated type B aortic dissection but whether this should be performed in uncomplicated cases has been a matter of debate. Randomized controlled trials have demonstrated the long-term benefit of endovascular treatment to prevent aortic-related mortality, however pre-emptive surgery may not be the solution for all patients because of the occurrence of adverse events such death, stroke and paraplegia. Morphological and false lumen characteristics including aortic diameter, the position, size and number of entry tears and false lumen thrombus volume have been shown to serve as predictors of outcome and may be used to identify high-risk patients. Functional imaging methods such as magnetic resonance and echocardiography are evolving and may be able to provide the clinically-relevant structural, hemodynamic and biomechanical information that is needed for accurate risk stratification of individual patients. A patient-specific approach designed to intervene only in patients that are at high risk of developing complications should improve the long-term outcome of these patients.