Characteristics, incidence, and outcomes of gastrointestinal complications post cardiac surgery in a quaternary referral centre: A retrospective study.

BACKGROUND: Gastrointestinal (GI) complications after cardiac surgery are associated with high morbidity and mortality. Early identification and treatment of GI complications could improve patient outcomes. OBJECTIVES: The objective of this study was to ascertain the incidence, risk factors, and clinical outcomes of GI complications following cardiac surgery. METHODS: A retrospective single-centre cohort study of adult patients undergoing cardiac surgery in an Australian quaternary cardiothoracic surgical referral centre was conducted from November 2012 to March 2020. Preoperative, intraoperative, and postoperative characteristics were compared between patients who did and did not develop GI complications. Data are presented as n (%). Between-group comparisons were analysed using Chi-square and Fisher's exact tests (where n < 6) for categorical variables and Wilcoxon rank-sum test for continuous variables. RESULTS: Of the 4417 patients who underwent cardiac surgery, 95 (2.2%) patients developed a total of 100 GI complications, with the most common being paralytic ileus (n = 22/100, 22%). Baseline characteristics and preoperative factors associated with GI complications included an age of >70 years (GI complication vs no GI complication: 55.8% vs 37.6%; p = 0.000), preexisting diabetes (49.5% vs 34.5%; p = 0.002), and a creatinine level >200 mcg/ml (11.6% vs 3.7%; p = 0.000). Intra-operative factors included a cardiopulmonary bypass time >120 min (28.4% vs 15.5%; p < 0.01). Postoperatively, developing a GI complication was associated with return to theatre (36.8% vs 13.9%; p < 0.01) and new stroke, pneumonia, and acute kidney injury (all p < 0.01). Patients with a GI complication had a higher intensive care unit and hospital mortality (7.4% vs 1.1%, and 13.6% vs 1.4%, respectively), and a longer intensive care unit and hospital stay (5.5 vs 2.3 days, and 24.0 vs 10.3 days). CONCLUSIONS: Multiple risk factors associated with GI complications in cardiac surgery patients were identified. These provide potential targets to support the early detection and management of GI complications to reduce morbidity and mortality in these patients.

The effects of computerised cognitive training on post-CABG delirium and cognitive change: A prospective randomised controlled trial.

Background: Cognitive impairments, including delirium, are common after coronary artery bypass grafting (CABG). Improving cognition pre- and post-operatively using computerised cognitive training (CCT) may be an effective approach to improve cognitive outcomes in CABG patients. Objectives: Investigate the effect of remotely supervised CCT on cognitive outcomes, including delirium, in older adults undergoing CABG surgery. Methods: Thirty-six participants, were analysed in a single-blinded randomised controlled trial (CCT Intervention: n = 18, Control: n = 18). CCT was completed by the intervention group pre-operatively (every other day, 45-60-minute sessions until surgery) and post-operatively, beginning 1-month post-CABG (3 x 45-60-minute sessions/week for 12-weeks), while the control group maintained usual care plus weekly phone calls. Cognitive assessments were conducted pre- and post-operatively at multiple follow-ups (discharge, 4-months and 6-months). Post-operative delirium incidence was assessed daily until discharge. Cognitive change data were calculated at each follow-up for each cognitive test (Addenbrooke's Cognitive Examination III and CANTAB; z-scored). Results: Adherence to the CCT intervention (completion of three pre-operative or 66% of post-operative sessions) was achieved in 68% of pre-CABG and 59% of post-CABG participants. There were no statistically significant effects of CCT on any cognitive outcome, including delirium incidence. Conclusion: Adherence to the CCT program was comparatively higher than previous feasibility studies, possibly due to the level of supervision and support provided (blend of face-to-face and home-based training, with support phone calls). Implementing CCT interventions both pre- and post-operatively is feasible in those undergoing CABG. No statistically significant benefits from the CCT interventions were identified for delirium or cognitive function post-CABG, likely due to the sample size available (study recruitment greatly impacted by COVID-19). It also may be the case that multimodal intervention would be more effective.

Clinical Outcomes in Surgical and Transcatheter Aortic Valve Replacement: An ANZSCTS Database Review 2001-2019.

BACKGROUND: Since the last formal publication reporting on the findings of the Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) database on surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) in 2016, transcatheter approaches have become common practice. There has been an increase in use of TAVR following large, randomised control trials that only report on short-term outcomes in a selective cohort. This study aims to report on primary outcome measures and identify complications associated with SAVR and TAVR from a large national database. METHODS: From the ANZSCTS database (2001-19), 14,097 SAVR and 1,194 TAVR patients were identified with clinical details and 30-day follow-up available. The primary endpoint was the composite of all-cause mortality and/or permanent stroke at 30 days. Secondary endpoints were post-procedure complications requiring treatment. Logistical regression followed by propensity score matching was performed. RESULTS: Using logistical regression when all patient factors considered for all patients who had SAVR and TAVR, the only preoperative factors that had an impact on 30-day mortality was cerebrovascular disease, respiratory disease, preoperative dialysis, angina, and hypertension. Primary outcome 30-day mortality rate was 1.83% in the SAVR group, and 1.68% in patients in the TAVR group, p=0.7001, and permanent stroke was seen in 1.07% patients in the SAVR group, and 1.26% patients in the TAVR group. Acute limb ischaemia, aortic dissection, ventricular tachycardia, bradyarrhythmia and heart block were more common following TAVR (p<0.001), while reintubation and atrial arrhythmia were more common following SAVR (p<0.001). CONCLUSIONS: In the real world SAVR and TAVR have been used in very different patient groups and it is difficult to compare as different baseline characteristics and complications. The two patient groups maintain similarities in primary and secondary endpoints, but differences in life threatening and life altering morbidity remains significant. Collection of SAVR and TAVR data in a combined database may help to better capture and compare these complications and institute strategies to prevent them.

Quality of life and frailty outcomes following surgical and transcatheter aortic valve replacement.

BACKGROUND: Our objective was to report on the prospective outcomes in the areas of depression, quality of life, angina, and frailty in SAVR and TAVR patients with aortic stenosis undergoing aortic valve intervention. METHODS: We recruited 300 patients across 3 groups (TAVR, SAVR, and CABG) over 12 months. Depression, quality of life, frailty, and angina were assessed followed by propensity score matching. RESULTS: Using logistical regression when all patient factors considered for all patients who had SAVR and TAVR, the only preoperative factors that impacted on 1 year mortality was hypertension and STS score. Quality of life improvements within each group over 12 months was significant (p value = 0.0001). Depression at 12 months between groups (p value = 0.0395) and within each group was significant (p value = 0.0073 for SAVR and 0.0001 for TAVR). Angina was most frequent in TAVR at 12 months in the QL (p = 0.0001), PL (p = 0.0007), and improvement was significant in the QL (SAVR p = 0.0010, TAVR p = 0.0001) and PL (SAVR p = 0.0002), TAVR p = 0.0007) domains in both groups. Frailty at 12 months improved in both groups, but was greatest in TAVR (p value = 0.00126). CONCLUSIONS: This 12 months follow up of cardiac surgical patients has revealed significant improvement in PROMs and frailty in all groups by 3 months postoperative regardless of surgical or transcatheter approach. Outcome measures of quality of life and frailty could be utilized as a measure of outcome more regularly in patients undergoing aortic valve surgery regardless of approach.

Cardiac surgery on patients with COVID-19: a systematic review and meta-analysis.

INTRODUCTION: The COVID-19 pandemic has had a significant impact on global surgery. In particular, deleterious effects of SARS-CoV-2 infection on the heart and cardiovascular system have been described. To inform surgical patients, we performed a systematic review and meta-analysis aiming to characterize outcomes of COVID-19 positive patients undergoing cardiac surgery. METHODS: The study protocol was registered with PROSPERO (CRD42021228533) and conformed with PRISMA 2020 and MOOSE guidelines. PubMed, Ovid MEDLINE and Web of Science were searched between 1 January 2019 to 24 February 2022 for studies reporting outcomes on COVID-19 positive patients undergoing cardiac surgery. Study screening, data extraction and risk of bias assessment were conducted in duplicate. Meta-analysis was conducted using a random-effects model where at least two studies had sufficient data for that variable. RESULTS: Searches identified 4223 articles of which 18 studies were included with a total 44 patients undergoing cardiac surgery. Within these studies, 12 (66.7%) reported populations undergoing coronary artery bypass graft (CABG) surgery, three (16.7%) aortic valve replacements (AVR) and three (16.7%) aortic dissection repairs. Overall mean postoperative length of ICU stay was 3.39 (95% confidence interval (CI): 0.38, 6.39) and mean postoperative length of hospital stay was 17.88 (95% CI: 14.57, 21.19). CONCLUSION: This systematic review and meta-analysis investigated studies of limited quality which characterized cardiac surgery in COVID-19 positive patients and demonstrates that these patients have poor outcomes. Further issues to be explored are effects of COVID-19 on decision-making in cardiac surgery, and effects of COVID-19 on the cardiovascular system at a cellular level.

Eukaryotic elongation factor 2 kinase regulates foam cell formation via translation of CD36.

Eukaryotic elongation factor 2 kinase (eEF2K) is an atypical protein kinase that controls protein synthesis in cells under stress. Although well studied in cancer, less is known about its roles in chronic inflammatory diseases. Here, we examined its regulation of macrophage cholesterol handling in the context of atherosclerosis. eEF2K mRNA expression and protein activity were upregulated in murine bone marrow-derived macrophages (BMDMs) exposed to oxidized low-density lipoprotein cholesterol (oxLDL). When incubated with oxLDL, BMDMs from eEF2K knockout (Eef2k-/- ) mice formed fewer Oil Red O+ foam cells than Eef2k+/+ BMDMs (12.5% ± 2.3% vs. 32.3% ± 2.0%, p < .01). Treatment with a selective eEF2K inhibitor, JAN-384, also decreased foam cell formation for C57BL/6J BMDMs and human monocyte-derived macrophages. Disabling eEF2K selectively decreased protein expression of the CD36 cholesterol uptake receptor, mediated by a reduction in the proportion of translationally active Cd36 mRNA. Eef2k-/- mice bred onto the Ldlr-/- background developed aortic sinus atherosclerotic plaques that were 30% smaller than Eef2k+/+ -Ldlr-/- mice after 16 weeks of high cholesterol diet (p < .05). Although accompanied by a reduction in plaque CD36+ staining (p < .05) and lower CD36 expression in circulating monocytes (p < .01), this was not associated with reduced lipid content in plaques as measured by oil red O staining. Finally, EEF2K and CD36 mRNA levels were higher in blood mononuclear cells from patients with coronary artery disease and recent myocardial infarction compared to healthy controls without coronary artery disease. These results reveal a new role for eEF2K in translationally regulating CD36 expression and foam cell formation in macrophages. Further studies are required to explore therapeutic targeting of eEF2K in atherosclerosis.

The susceptibility of the aortic root: porcine aortic rupture testing under cardiopulmonary bypass.

BACKGROUND: In our earlier study on the functional limits of the aneurysmal aortic root we determined the pig root is susceptible to failure at high aortic pressures levels. We established a pig rupture model using cardiopulmonary bypass to determine the most susceptible region of the aortic root under the highest pressures achievable using continuous flow, and what changes occur in these regions on a macroscopic and histological level. This information may help guide clinical management of aortic root and ascending aorta pathology. METHODS: Five pigs underwent 4D flow MRI imaging pre surgery to determine vasopressor induced wall sheer stress and flow parameters. All pigs were then placed on cardiopulmonary bypass (CPB) via median sternotomy, and maximal aortic root and ascending aorta flows were initiated until rupture or failure, to determine the most susceptible region of the aorta. The heart was explanted and analysed histologically to determine if histological changes mirror the macroscopic observations. RESULTS: The magnetic resonance imaging (MRI) aortic flow and wall sheer stress (WSS) increased significantly in all regions of the aorta, and the median maximal pressures obtained during cardiopulmonary bypass was 497 mmHg and median maximal flows was 3.96 L/m. The area of failure in all experiments was the non-coronary cusp of the aortic valve. Collagen and elastin composition (%) was greatest in the proximal regions of the aorta. Collagen I and III showed greatest content in the inner aortic root and ascending aorta regions. CONCLUSIONS: This unique porcine model shows that the aortic root is most susceptible to failure at high continuous aortic pressures, supported histologically by different changes in collagen content and subtypes in the aortic root. With further analysis, this information could guide management of the aortic root in disease.

Histological regional analysis of the aortic root and thoracic ascending aorta: a complete analysis of aneurysms from root to arch.

BACKGROUND: Although aortic root and ascending aortic aneurysms are treated the same, they differ in embryological development and pathological processes. This study examines the microscopic structural differences between aortic root and ascending aortic aneurysms, correlating these features to the macroscopic pathophysiological processes. METHODS: We obtained surgical samples from ascending aortic aneurysms (n = 11), aortic root aneurysms (n = 3), and non-aneurysmal patients (n = 7), Aortic collagen and elastin content were examined via histological analysis, and immunohistochemistry techniques used to determine collagen I, III, and IV subtypes. Analysis was via observational features, and colour deconvolution quantification techniques. RESULTS: Elastin fiber disruption and fragmentation was the most extensive in the proximal aneurysmal regions. Medial fibrosis and collagen density increased in proximal aneurysmal regions and aortic root aneurysms (p < 0.005). Collagen I was seen in highest quantity in aortic root aneurysms. Collagen I content was greatest in the sinus tissue regions compared to the valvular and ostial regions (p < 0.005) Collagen III and IV quantification did not vary greatly. The most susceptible regions to ultrastructural changes in disease are the proximal ascending aorta and aortic root. CONCLUSIONS: The aortic root differs histologically from the ascending aorta confirming its unique composition in aneurysm pathology. These findings should prompt further evaluation on the influence of this altered structure on function which could potentially guide clinical management.

Hybrid ablation for atrial fibrillation: A systematic review and meta-analysis.

Background: Both catheter and surgical ablation strategies offer effective treatments of atrial fibrillation (AF). The hybrid (joint surgical and catheter) ablation for AF is an emerging rhythm control strategy. We sought to determine the efficacy and safety of hybrid ablation of AF. Methods: Systematic review and meta-analysis interrogating PubMed, EMBASE, and Cochrane databases from January 1, 1991, to November 30, 2017, using the following search terms: "Cox-maze," "mini-maze," "ablation methods (including radiofrequency, cryoablation, cryomaze)," and "surgery." Included studies required ablation procedures to be hybrid and report rhythm follow-up. Results: We included 925 patients with AF (38% persistent, 51% longstanding persistent) from 22 single-center studies (mean follow-up of 19 months). The surgical lesion set consisted of pulmonary vein isolation (n = 11) or box lesion (n = 11) with variable additional linear ablation. This was followed by sequential (n = 9), staged (n = 9), or combination (n = 4) catheter-based ablation to ensure isolation of pulmonary veins and to facilitate additional ablation or consolidation of surgically ablated lines. Overall, sinus rhythm maintenance was 79.4% (95% confidence interval [CI], 72.4-85.7] and 70.7% (95% CI, 62.2-78.7) with and without antiarrhythmic drugs, respectively at 19 ± 25 (range, 6-128) months. The use of the bipolar AtriCure Synergy system and left atrial appendage exclusion conferred superior rhythm outcome without antiarrhythmic drugs (P ≤ .01). The overall complication rate was 6.5% (95% CI, 3.4-10.2): mortality 0.2% (95% CI, 0-0.9); stroke 0.3% (95% CI, 0-1.1); reoperation for bleeding 1.6% (95% CI, 0.6-3.0); permanent pacing ~0% (95% CI, 0-0.5); conversion to sternotomy 0.3% (95% CI, 0-1.1); atrioesophageal fistula ~0% (95% CI, 0-0.5); and phrenic nerve injury 0.3% (95% CI, 0-1.1). Conclusions: Hybrid ablation therapy for AF demonstrates favorable rhythm outcome with acceptable complication rates.

The functional limits of the aneurysmal aortic root. A unique pressure testing apparatus.

BACKGROUND: The aortic root has unique embryological development and is a highly sophisticated and complex structure. In studies that report on the biomechanical characteristics of the thoracic aorta, distinction between the aortic root and ascending aorta regions is nonexistent. Our objective is to determine the maximal pressures at which dissection occurs or tissue failure occurs in the aortic root compared to that of the ascending aorta in the presence of aortic aneurysms. This may help guide preoperative monitoring, diagnosis and the decision for operative intervention for aortic root aneurysms in the normal and susceptible populations. METHODS: We developed a simple aortic root and ascending aorta pressure testing unit in series. Ten fresh porcine hearts were obtained from the local abattoir (n = 5 aortic root and n = 5 ascending aorta for comparison). Using a saline filled needle and syringe, artificial fluid-filled aneurysms were created between the intima and medial layers of the aortic root. The aorta lumen was then progressively filled with saline solution. Pressure measurement was taken at time of loss of tissue integrity, obvious tissue dissection or aneurysm rupture, and the tissue structure was then visually examined. RESULTS: In the aortic root, mean maximal pressure (mmHg) at tissue failure was 208 mmHg. Macroscopic examination revealed luminal tears around the coronary ostia in 2/5 specimens, and in all specimens, there was propagation of the dissection in the aortic root in a circumferential direction. In all ascending aorta specimens, the maximal aortic pressures exceeded 300 mmHg without tissue failure or dissection, and eventual apparatus failure. CONCLUSION: Our results indicate that the aneurysmal aortic root tissues are at greater risk of rupture and dissection propagation at lower aortic pressure. With further analysis, this could guide clinical and surgical management.

How to do whole lung lavage for treatment of pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis is a rare condition characterized by progressive accumulation of surfactant lipoproteins in the alveolar space, leading to poor gas exchange. We describe our technique of whole lung lavage for management of pulmonary alveolar proteinosis.

Computerised cognitive training to improve cognition including delirium following coronary artery bypass grafting surgery: protocol for a blinded randomised controlled trial.

INTRODUCTION: Coronary artery bypass grafting (CABG) surgery is known to improve vascular function and cardiac-related mortality rates; however, it is associated with high rates of postoperative cognitive decline and delirium. Previous attempts to prevent post-CABG cognitive decline using pharmacological and surgical approaches have been largely unsuccessful. Cognitive prehabilitation and rehabilitation are a viable yet untested option for CABG patients. We aim to investigate the effects of preoperative cognitive training on delirium incidence, and preoperative and postoperative cognitive training on cognitive decline at 4 months post-CABG. METHODS AND ANALYSIS: This study is a randomised, single-blinded, controlled trial investigating the use of computerised cognitive training (CCT) both pre-CABG and post-CABG (intervention group) compared with usual care (control group) in older adults undergoing CABG in Adelaide, South Australia. Those in the intervention group will complete 1-2 weeks of CCT preoperatively (45-60 min sessions, 3.5 sessions/week) and 12 weeks of CCT postoperatively (commencing 1 month following surgery, 45-60 min sessions, 3 sessions/week). All participants will undergo cognitive testing preoperatively, over their hospital stay including delirium, and postoperatively for up to 1 year. The primary delirium outcome variable will be delirium incidence (presence vs absence); the primary cognitive decline variable will be at 4 months (significant decline vs no significant decline/improvement from baseline). Logistic regression modelling will be used, with age and gender as covariates. Secondary outcomes include cognitive decline from baseline to discharge, and at 6 months and 1 year post-CABG. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Central Adelaide Local Health Network Human Research Ethics Committee (South Australia, Australia) and the University of South Australia Human Ethics Committee, with original approval obtained on 13 December 2017. It is anticipated that approximately two to four publications and multiple conference presentations (national and international) will result from this research. TRIAL REGISTRATION NUMBER: This clinical trial is registered with the Australian New Zealand Clinical Trials Registry and relates to the pre-results stage. Registration number: ACTRN12618000799257.

Sex differences in vascular reactivity of coronary artery bypass graft conduits.

Females have increase in-hospital mortality and poorer outcomes following coronary artery bypass grafting (CABG). Biological differences in the reactivity of the graft conduits to circulating catecholamine may contribute to this sex difference. This study examined sex differences in the vasoconstrictor responses of internal mammary artery (IMA) and saphenous vein (SV) conduits to phenylephrine (PE) and endothelin-1 (ET-1). Functional IMA and SV were obtained from 78 male and 50 female patients undergoing CABG (67.7 ± 11 and 69 ± 10 years, respectively) and subjected to the following experimental conditions. (1) Concentration response curves for PE and ET-1 were generated in an intact IMA and SV and endothelium denuded IMA segments, (2) in the presence of the nitric oxide synthase inhibitor (L-NAME) or the cyclooxygenase inhibitor (indomethacin) in an endothelium-intact IMA and (3) the activity state (abundance and phosphorylation) of the α1-adrenergic receptor was investigated using Phos-tag™ western blot analysis. (1) Compared to male, female IMA and SV were hypersensitive to PE but not ET-1 (p < 0.05). The female IMA hypersensitivity response to PE was abolished following endothelial denudation, (2) persisted in the presence of L-NAME but was abolished in the presence of indomethacin and (3) there was no sex differences in the abundance and phosphorylation of the α1-adrenergic receptor in IMA. Female IMA and SV graft conduits are hypersensitive to α1-adrenergic stimuli. This endothelial cyclooxygenase pathway-mediated hypersensitivity may produce excessive IMA and SV graft constriction in females administered catecholamines and could contribute to their poorer CABG outcomes.

Mortality in Australian Cardiothoracic Surgery: Findings From a National Audit.

BACKGROUND: Independent peer review of mortality cases has potential to identify issues in cardiothoracic surgical patients. The Australian and New Zealand Audit of Surgical Mortality aims to improve surgical care through peer-reviewed assessment of all surgical mortality. The aim of this study was to describe common clinical management issues that contribute to patient mortality in a cohort of Australian cardiothoracic surgical patients. This approach may subsequently provide a basis for quality improvement. METHODS: Cardiothoracic mortality reports to the Australian and New Zealand Audit of Surgical Mortality from February 2009 through December 2015 were reviewed. The surgeon report and assessor comments were coded to identify clinical management issues. These were divided into perioperative stages (preoperative, intraoperative, and postoperative), and at each stage a thematic analysis was performed. RESULTS: Of the 908 cases analyzed, 1371 clinical management issues were identified. Postoperative issues were the most common (n = 552), followed by preoperative (n = 378) and intraoperative issues (n = 370). Communication issues were present at all 3 stages (n = 71). Overall the most common theme was intraoperative technical issues (n = 287). Many of these issues revolved around unintentional injury to anatomic structures during surgery and inadequate myocardial protection. Communication issues commonly related to surgical handover to the intensive care unit and lack of shared decision-making. Also common were consultant surgeons being unaware of patient deterioration or significant changes in management. CONCLUSIONS: The Australian and New Zealand Audit of Surgical Mortality provides valuable insights into issues affecting mortality in cardiothoracic patients. Potentially avoidable management issues play a large role in determining the outcome of these patients. Quality improvement initiatives targeting these areas may be valuable.

Surgeon's Focussed Ultrasound Examination of the Long Saphenous Vein Reduces Surgical Time and Wound Complications.

BACKGROUND: Despite increased use of arterial grafts, the long saphenous vein (LSV) is often utilised as conduit for coronary artery bypass graft (CABG). Preoperative ultrasound (U/S) vein assessment is limited to patients with varicosities, clinical signs suggestive of poor vein conduits and a history of cardiac or vascular surgery. The aim of this study was to evaluate the usefulness and logistics of the surgeon incorporating intraoperative U/S assessment of the LSV into their regular practice. METHODS: All patients undergoing coronary artery revascularisation and open vein harvest in our institution were recruited from July 2016 to February 2017. Demographics, including known risk factors for wound complications were documented, in addition to surgical details such as harvest time, vein length and surgical repairs of the conduit. Focussed U/S assessment was performed intraoperatively by the surgical registrar before beginning the procedure. The diameter of the leg pre and postoperatively, as well as the incidence, type and severity of wound complications were documented for further statistical analysis. RESULTS: A total of 103 patients were included in this study. Two patients died perioperatively and were excluded from the study. The remaining 101 patients were separated in two cohorts-U/S group (n=32) and blind technique group (n=69). Demographics were similar between the groups, whilst other risk factors for harvest complications, such as presence of superficial varicosities on clinical examination and renal failure were significantly more frequent in the U/S group. The median harvest time was significantly lower within the U/S group (25 mins versus 40 mins; p=0.001), as was the rate of overall wound complications (6.2% vs 23.2%; p=0.04). CONCLUSIONS: Ultrasound assessment of the LSV by the surgical team intraoperatively is feasible, easy to learn and does not demand extra costs or delays. It significantly reduces surgical harvest time and it is associated with a reduced incidence of wound complications, swelling and postoperative mobility impairment.

"Nobody told me": Communication Issues Affecting Australian Cardiothoracic Surgery Patients.

BACKGROUND: Failure of communication can have potentially severe results in cardiothoracic surgery. Previous literature regarding patient safety highlighted communication as a common area for improvement. This study utilized a qualitative approach to analyze a national mortality audit data set to identify and describe communication issues that could potentially contribute to patient mortality following cardiothoracic surgery. METHODS: We utilized a peer-reviewed audit of surgical deaths after cardiothoracic surgery in Australian hospitals from 2009 to 2015 via the Australian and New Zealand Audit of Surgical Mortality. Cases were identified with clinical management issues then individual analysis of cases highlighting communication issues was undertaken. A total of 91 reports from surgeons and assessors were analysed using a thematic analytic approach. RESULTS: A total of 908 cases of potentially avoidable mortality were identified as being associated with clinical management issues, and communication issues were identified in 91 (10%) of these cases, which served as the basis for this analysis. The study found that failure to achieve shared decision making was the most common theme (n = 38, 41.8%), followed by failure to notify patient deterioration (n = 22, 24.1%), misreporting of patient condition (n = 10, 11.0%) and issues related to informed consent (n = 9, 10.0%). The most frequent communication issues occurred between surgeons and the intensive care unit. CONCLUSIONS: Poor communication was identified in patients who died after cardiothoracic surgery. Communication is an important modifiable factor in patient mortality. Efforts to address teamwork and communication have the potential to improve safety and quality of care for patients undergoing cardiothoracic surgery.

Cardiopulmonary Bypass in Non-Cardiac Surgery.

BACKGROUND: Cardiopulmonary bypass (CPB) and extracorporeal membrane oxygenation (ECMO) are used to facilitate circulatory support in standard cardiac surgery and emergency intervention, but CPB and ECMO are not used routinely in non-cardiac surgery involving the thorax and major vessels. The primary aim of this study was to identify the type of non-cardiac procedures and bypass used in our institution and review the patient outcomes including perioperative and bypass complications. METHODS: A retrospective study was performed within the Royal Adelaide Hospital Cardiothoracic Surgery Unit (CTSU) that examined all operations between 2006 and 2014. There were 1,816 non-cardiac cases, of these nine used CPB or ECMO. Cases excluded from the study were those that required cardiac surgical management with the use of CPB or ECMO. RESULTS: Twelve (12) non-cardiac surgery cases were reviewed, with three, and nine cases, respectively, using ECMO and CPB standby or support. The non-cardiac surgical procedures included eight thoracic cases, two renal cases and two tracheal cases. Of the thoracic cases, five were elective, two were bailout and one was an emergency. Both renal cases were bailout (with one as major vessel support and one as standby). Both tracheal cases were bailout (one as an emergency and one as standby). Intraoperative complications included severe haemorrhage in three cases. General postoperative complications included increased analgesia requirement, atelectasis, fever; and prolonged ECMO support and ICU stay which occurred in seven cases. No direct complications of CPB or ECMO are reported. Four of the 12 cases that encompassed thoracic, renal and tracheal surgery are discussed in detail. CONCLUSIONS: Our review of 12 cases managed under the CTSU has shown that extracorporeal circulatory support can be used in a range of thoracic, renal and tracheal surgery. These surgical procedures have involved the management of haemodynamically unstable patients. Patient outcomes have been encouraging with few complications. With further research including the use of a larger sample size and control groups, more definitive conclusions could be made on the benefit of CPB and ECMO to patients in non-cardiac surgery.

Contact force and ablation assessment of surgical bipolar radiofrequency clamps in the treatment of atrial fibrillation.

OBJECTIVES: Atrial fibrillation is treated surgically by creating conduction block lesions. Radiofrequency (RF) lesions have reduced efficacy compared to 'cut-and-sew'. Catheter ablation studies demonstrate a relationship between lesion depth and contact force. We hypothesized that contact force and lesion depth are dependent on design of the bipolar surgical RF clamps. METHODS: Hinged and parallel jaw style RF clamps were studied. Muscle samples were clamped with pressure-sensitive film at increasing tissue thicknesses. Films were analysed determining clamp pressure profiles. A sheep model was utilized for ablation testing using each clamp style until the device indicated transmurality. Separate muscle areas had 1, 2 or 3 burns applied. The muscle was excised, sectioned every 1 cm and stained for lesion depth and fat thickness analysis. RESULTS: Pressure profiling comparing the proximal and distal segments of each clamp style demonstrated only one statistically significant difference in the parallel clamp; the hinged clamp had statistically significant differences (P ≤ 0.03) for all tissue thicknesses. There was no evidence for differences in the proximal lesion depth of both clamps (P = 0.13) but deeper distally in the parallel clamp (10.17 mm vs 8.02 mm, P = 0.003). The logistic regression analysis demonstrated increased odds of transmurality with parallel clamps at 1, 2 or 3 burns (P = 0.03, P = 0.003 and P = 0.002). Every 1 mm increase in overlying fat decreased likelihood of transmurality by 11% (P < 0.05). CONCLUSIONS: The parallel and hinged clamps have different pressure profiles with higher likelihood of transmurality using the parallel clamp. Fat reduces the ability of RF to deliver a transmural lesion. These findings have implications for optimal surgical RF ablation technique.