Faculty development review: Improving learning in the operating theatre.

BACKGROUND: Undergraduate medical students' time is precious, and with increasingly limited exposure to surgery, learning at every opportunity needs to be facilitated. The operating theatre is a unique classroom and factors related to this environment could impact on learning opportunities. We aim to help surgical faculty overcome these barriers and develop the operating theatre's potential as a learning environment. RESULTS: Reports in the literature frequently mention the emotional aspects of attending theatre and trying to fit in with the surgical team, and often report negative feelings such as feeling unwelcome. Students also report feeling confused about what they should be hoping to learn from their theatre experience, and what their role is in theatre. CONCLUSION: We suggest ways in which surgical faculty can help the student fit into the theatre environment and hope that this will improve undergraduate surgical education and enthusiasm for surgery.

Contrast-enhanced ultrasound and/or colour duplex ultrasound for surveillance after endovascular abdominal aortic aneurysm repair: a systematic review and economic evaluation.

BACKGROUND: Endovascular abdominal aortic aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA) is less invasive than open surgery, but may be associated with important complications. Patients receiving EVAR require long-term surveillance to detect abnormalities and direct treatments. Computed tomography angiography (CTA) has been the most common imaging modality adopted for EVAR surveillance, but it is associated with repeated radiation exposure and the risk of contrast-related nephropathy. Colour duplex ultrasound (CDU) and, more recently, contrast-enhanced ultrasound (CEU) have been suggested as possible, safer, alternatives to CTA. OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness of imaging strategies, using either CDU or CEU alone or in conjunction with plain radiography, compared with CTA for EVAR surveillance. DATA SOURCES: Major electronic databases were searched, including MEDLINE, EMBASE, Science Citation Index, Scopus' Articles-in-Press, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE) and NHS Economic Evaluation Database from 1996 onwards. We also searched for relevant ongoing studies and conference proceedings. The final searches were undertaken in September 2016. METHODS: We conducted a systematic review of randomised controlled trials and cohort studies of patients with AAAs who were receiving surveillance using CTA, CDU and CEU with or without plain radiography. Three reviewers were involved in the study selection, data extraction and risk-of-bias assessment. We developed a Markov model based on five surveillance strategies: (1) annual CTA; (2) annual CDU; (3) annual CEU; (4) CDU together with CTA at 1 year, followed by CDU on an annual basis; and (5) CEU together with CTA at 1 year, followed by CEU on an annual basis. All of these strategies also considered plain radiography on an annual basis. RESULTS: We identified two non-randomised comparative studies and 25 cohort studies of interventions, and nine systematic reviews of diagnostic accuracy. Overall, the proportion of patients who required reintervention ranged from 1.1% (mean follow-up of 24 months) to 23.8% (mean follow-up of 32 months). Reintervention was mainly required for patients with thrombosis and types I-III endoleaks. All-cause mortality ranged from 2.7% (mean follow-up of 24 months) to 42% (mean follow-up of 54.8 months). Aneurysm-related mortality occurred in < 1% of the participants. Strategies based on early and mid-term CTA and/or CDU and long-term CDU surveillance were broadly comparable with those based on a combination of CTA and CDU throughout the follow-up period in terms of clinical complications, reinterventions and mortality. The economic evaluation showed that a CDU-based strategy generated lower expected costs and higher quality-adjusted life-year (QALYs) than a CTA-based strategy and has a 63% probability of being cost-effective at a £30,000 willingness-to-pay-per-QALY threshold. A CEU-based strategy generated more QALYs, but at higher costs, and became cost-effective only for high-risk patient groups. LIMITATIONS: Most studies were rated as being at a high or moderate risk of bias. No studies compared CDU with CEU. Substantial clinical heterogeneity precluded a formal synthesis of results. The economic model was hindered by a lack of suitable data. CONCLUSIONS: Current surveillance practice is very heterogeneous. CDU may be a safe and cost-effective alternative to CTA, with CTA being reserved for abnormal/inconclusive CDU cases. FUTURE WORK: Research is needed to validate the safety of modified, more-targeted surveillance protocols based on the use of CDU and CEU. The role of radiography for surveillance after EVAR requires clarification. STUDY REGISTRATION: This study is registered as PROSPERO CRD42016036475. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Contemporary outcomes of open repair of thoracoabdominal aortic aneurysm in young patients.

BACKGROUND: Endovascular technology now permits total endovascular thoracoabdominal aortic aneurysm (TAAA) repair with high volume centres reporting encouraging results. The long-term durability of such stent grafts is unknown, leading to concerns regarding their use in younger patients. This study reports contemporary outcomes of open repair in young patients. METHODS: Outcomes for patients age 60 or younger undergoing open TAAA repair between June 1999 and August 2013 with prospective collected data were analysed retrospectively. RESULTS: Thirty-seven patients (31 men, 84%) with a median age of 56 (range 22-60) were identified with a median TAAA diameter of 6.9 cm (range 5.6-11). Aneurysm aetiology included degenerative change (18), dilation of chronic dissection (10), connective tissue disease (7) and mycotic degeneration (2). Crawford Type IV TAAA were most commonly treated (17), followed by Type II (10), Type III (7) and Type I (3). Two (5%) patients died in hospital, one from multiple organ failure and one from respiratory failure. Three patients (8%) developed temporary paraplegia, all of whom made a complete recovery and 4 (11%) patients required temporary renal replacement therapy. Median critical care stay was 5 days (range 2-28) with an in-hospital stay of 14 days (range 7-83). During a median follow-up of 72 months (range 13-171), no patient subsequently required any further aneurysm related surgical or radiological intervention. The mean (SEM) survival time was 138.5 (11) months. The 5 year survival was 79.7% (8.3) including early deaths, with no aneurysm related complications. CONCLUSIONS: The outcome of open TAAA repair in patients aged less than 60 years is favorable. It is against these results that evolving endovascular interventions must be compared.

Early Australasian experience with branched endovascular thoracoabdominal aortic aneurysm repair.

INTRODUCTION: Endovascular technology can now support total endovascular thoracoabdominal aortic aneurysm repair with branches maintaining visceral and renal perfusion thus avoiding the need for massive open surgery. High-volume centres have reported encouraging results. We report our Australasian experience of 10 cases including the first-in-man 'off-the-shelf' graft. METHODS: Ten consecutive endovascular repairs performed with prospective data collection have been retrospectively analysed. RESULTS: Six men and four women with an average age of 72.4 years (range 55-85) were treated between 2009 and 2012. The mean aneurysm diameter was 7 cm (range 4.8-10.0) with aneurysms across all five Crawford classifications. One hundred per cent procedural technical success was achieved and all branches and fenestrations were patent at a median follow up of 12 months. In total, 30 branches were utilized together with seven fenestrations. One death from respiratory failure occurred on day 30 without endograft problems and there were two late aneurysm related deaths. Three patients experienced spinal cord ischaemia and one patient experienced two separate late endoleaks. Six patients had successful endografts and remain alive and well. DISCUSSION: For experienced endovascular surgeons working with a proctor 100% technical success in graft deployment is achievable. Endovascular skills alone do not guarantee long-term success; our results demonstrate the need for careful patient selection, the danger of spinal cord ischaemia and the potential for endoleaks.

Aortic graft preservation by debridement and omental wrapping.

BACKGROUND: Aortic graft infection is a rare, but grave, complication in vascular surgery. Graft removal together with extra-anatomical bypass or in situ graft replacement is usually advocated, but these procedures are associated with significant morbidity and mortality. METHODS AND RESULTS: Two cases of aortic graft infection in high-risk surgical candidates managed by open debridement and omental wrapping with graft preservation are described. Both remain well at 3 years without any adjunctive procedures. CONCLUSION: Debridement and omental wrapping may offer an alternative to graft removal and revascularization in selected patients. This relatively low-risk procedure may allow long-term survival.

Acute aortic occlusion with sudden paraplegia secondary to Aspergillus niger embolism from Aspergillus niger aortitis.

Acute aortic occlusion caused by a saddle embolus is a rare vascular emergency. Associated sudden paraplegia secondary to spinal cord ischemia is even more uncommon. Aspergillus surgical site infection is typically linked to cardiac surgery but is exceptional. Here we present a case that combines all of these factors. A 67-year-old man presented with sudden paraplegia from acute aortic occlusion with a saddle embolus from Aspergillus niger aortitis 4 months after aortic valve replacement and aortoplasty. We believe this to be the second reported case of Aspergillus niger aortitis and the first presenting as aortic occlusion with paraplegia.

Hepatic steatosis and normothermic perfusion-preliminary experiments in a porcine model.

BACKGROUND: Steatotic livers are increasingly common in the donor population. Cold storage of steatotic livers exacerbates ischemia-reperfuson injury and risks primary nonfunction and recipient death. Normothermic preservation avoids prolonged cooling of the organ and may be well suited to the preservation and resuscitation of damaged livers. By ex vivo normothermic perfusion, it may be possible to preserve and improve steatotic livers, so that transplantation is a viable option. METHODS: In a porcine model, streptozotocin was used to induce a hyperglycemic, ketotic state that, together with a high fat diet, resulted in mild hepatic steatosis at 5 weeks. A blood-based oxygenated ex vivo normothermic preservation system was then used to compare extended preservation of normal and mildly steatotic porcine livers at physiological pressures and flows. Serial liver biopsies were stained with Oil Red O, a specialist triglyceride stain, and were analyzed using custom-designed image analysis to quantify the degree of lipid deposition. RESULTS: Steatotic livers were capable of correcting the perfusate base excess and maintaining factor V and bile production and showed markers of liver injury comparable with normal livers. Steatotic livers had a significantly higher urea production and required no glucose support. Preliminary results suggest that prolonged normothermic perfusion results in a reduction in steatosis. CONCLUSIONS: This study suggests that steatotic livers can be successfully preserved using normothermic preservation for prolonged periods and that normothermic preservation facilitates a reduction in hepatic steatosis. Further studies are now needed including transplantation of steatotic livers after normothermic preservation.

Organ reperfusion and preservation.

Organ transplantation is one of the medical success stories of the 20th century. Transplantation is, however, a victim of its own success with demand for organs far exceeding supply. The ischemia/reperfusion injury associated with organ transplantation is complex with interlinking cellular pathways and cascades. With increasing use of marginal organs and better understanding of the consequences of ischemia/reperfusion, enhanced organ preservation is required. Traditional static cold preservation cannot prevent ischemia/reperfusion injury, the low temperature itself is damaging and viability testing is limited. Donor preconditioning techniques to enhance organ preservation in advance of retrieval are starting to show convergence on several key pathways (HO-1 and cell apoptosis). Microdialysis and bioimpedence techniques may allow viability assessment during cold storage. Hypothermic machine perfusion has a role to play, particularly in preservation of kidneys from non-heart-beating donors although results of clinical trials are awaited. Normothermic preservation offers benefits over cold storage (at least experimentally) by avoiding damage induced by low temperature, minimising ischemia/reperfusion injury and allowing resuscitation of damaged organs. Normothermic preservation is likely to increase as the average quality of donor organs declines and clinical trials are needed. In the long term, normothermic preservation may be used, not just to resuscitate organs, but facilitate organ immunomodulation.