Surgical aortic valve replacement in the era of transcatheter aortic valve implantation: a review of the UK national database

OBJECTIVES

To date the reported outcomes of surgical aortic valve replacement (SAVR) are mainly in the settings of trials comparing it with evolving transcatheter aortic valve implantation. We set out to examine characteristics and outcomes in people who underwent SAVR reflecting a national cohort and therefore 'real-world' practice.

DESIGN

Retrospective analysis of prospectively collected data of consecutive people who underwent SAVR with or without coronary artery bypass graft (CABG) surgery between April 2013 and March 2018 in the UK. This included elective, urgent and emergency operations. Participants' demographics, preoperative risk factors, operative data, in-hospital mortality, postoperative complications and effect of the addition of CABG to SAVR were analysed.

SETTING

27 (90%) tertiary cardiac surgical centres in the UK submitted their data for analysis.

PARTICIPANTS

31 277 people with AVR were identified. 19 670 (62.9%) had only SAVR and 11 607 (37.1%) had AVR+CABG.

RESULTS

In-hospital mortality for isolated SAVR was 1.9% (95% CI 1.6% to 2.1%) and was 2.4% for AVR+CABG. Mortality by age category for SAVR only were: <60 years=2.0%, 60-75 years=1.5%, >75 years=2.2%. For SAVR+CABG these were; 2.2%, 1.8% and 3.1%. For different categories of EuroSCORE, mortality for SAVR in low risk people was 1.3%, in intermediate risk 1% and for high risk 3.9%. 74.3% of the operations were elective, 24% urgent and 1.7% emergency/salvage. The incidences of resternotomy for bleeding and stroke were 3.9% and 1.1%, respectively. Multivariable analyses provided no evidence that concomitant CABG influenced outcome. However, urgency of the operation, poor ventricular function, higher EuroSCORE and longer cross clamp and cardiopulmonary bypass times adversely affected outcomes.

CONCLUSIONS

Surgical SAVR±CABG has low mortality risk and a low level of complications in the UK in people of all ages and risk factors. These results should inform consideration of treatment options in people with aortic valve disease.

Cardiac surgery outcome during the COVID-19 pandemic: a retrospective review of the early experience in nine UK centres

BACKGROUND

Early studies conclude patients with Covid-19 have a high risk of death, but no studies specifically explore cardiac surgery outcome. We investigate UK cardiac surgery outcomes during the early phase of the Covid-19 pandemic.

METHODS

This retrospective observational study included all adult patients undergoing cardiac surgery between 1st March and 30th April 2020 in nine UK centres. Data was obtained and linked locally from the National Institute for Cardiovascular Outcomes Research Adult Cardiac Surgery database, the Intensive Care National Audit and Research Centre database and local electronic systems. The anonymised datasets were analysed by the lead centre. Statistical analysis included descriptive statistics, propensity score matching (PSM), conditional logistic regression and hierarchical quantile regression.

RESULTS

Of 755 included individuals, 53 (7.0%) had Covid-19. Comparing those with and without Covid-19, those with Covid-19 had increased mortality (24.5% v 3.5%, p < 0.0001) and longer post-operative stay (11 days v 6 days, p = 0.001), both of which remained significant after PSM. Patients with a pre-operative Covid-19 diagnosis recovered in a similar way to non-Covid-19 patients. However, those with a post-operative Covid-19 diagnosis remained in hospital for an additional 5 days (12 days v 7 days, p = 0.024) and had a considerably higher mortality rate compared to those with a pre-operative diagnosis (37.1% v 0.0%, p = 0.005).

CONCLUSIONS

To mitigate against the risks of Covid-19, particularly the post-operative burden, robust and effective pre-surgery diagnosis protocols alongside effective strategies to maintain a Covid-19 free environment are needed. Dedicated cardiac surgery hubs could be valuable in achieving safe and continual delivery of cardiac surgery.

Free flap microvascular anastomosis in head and neck reconstruction using a 4K three-dimensional exoscope system (VITOM 3D)

The aim of this study was to evaluate the feasibility of microvascular anastomosis using a 4K three-dimensional exoscope system (VITOM 3D) in 10 consecutive cases of free flap head and neck reconstructive surgery. This was a clinical human study of free flap microvascular anastomosis using a VITOM 3D exoscope in 10 consecutive patients undergoing reconstruction after ablative surgery for head and neck carcinoma. Microvascular anastomoses were performed successfully using the exoscope in all patients, without any need for the conventional microscope. Arterial anastomoses were all end-to-end. Venous anastomoses were end-to-end in eight cases and end-to-side with the internal jugular vein in two cases. This study demonstrates the technical feasibility of microvascular anastomosis using a 4K three-dimensional exoscope system (VITOM 3D) in a series of 10 cases.

Intraoperative Epi-Aortic Scans Reduce Adverse Neurological Sequelae in Elderly, High Risk Patients Undergoing Coronary Artery Bypass Surgery - a Propensity Matched, Cumulative Sum Control Analysis

BACKGROUND

Adverse neurological sequelae are a major cause of morbidity and mortality after coronary artery bypass (CABG) surgery, due to manipulation of an atherosclerotic aorta. The purpose of this study is to measure the impact of intraoperative epi-aortic scanning in reducing neurologic sequelae after CABG, and the patient subgroups that are benefitted the most.

METHODS

Patients that underwent first-time CABG from July 2010 to March 2014 (n=1,989) were retrospectively reviewed and stratified by history of intraoperative epi-aortic scan (n=350) or no scan (n=1,639). Baseline characteristics, rates of adverse neurological events, and overall survival were compared among groups in both matched and unmatched cohorts and tested using Student's t-test, chi² test, or log-rank test, respectively. Multivariable analysis using logistic regression was performed to identify potential predictors for neurological sequelae. Cumulative summation plots (CUSUM) were constructed to display the number of preventable adverse neurological events per consecutive patient that underwent CABG. A p≤0.05 was considered statistically significant.

RESULTS

The use of epi-aortic scan (OR: 0.29, 95% CI: 0.09-0.99, p=0.48) was an independent predictor of adverse events. Overall rates of stroke (0.29% vs 0.55%), postoperative confusional state (1.43% vs 3.42%), or both (1.71% vs 3.72%) were lower in those scanned. CUSUM scores were higher in scanned patients, especially in those with an age above 70 years or logistic Euroscore >2.

CONCLUSIONS

Intraoperative epi-aortic scan is an effective assessment tool for atherosclerotic burden in the ascending aorta and can guide surgical strategy to decrease adverse neurological outcomes, particularly in high risk and elderly patients.

Discharge of thoracic patients on portable digital suction: Is it cost-effective?

OBJECTIVES

A portable suction drainage device for patients undergoing thoracic surgical procedures was introduced into our service in January 2010. Patients who met strict discharge criteria were allowed to continue their treatment at home with the device. They were monitored in a designated follow-up clinic. Data were collected to identify the impact of this service in relation to the duration of follow-up required, bed-days saved, and potential cost/benefits.

METHODS

All patients who underwent a thoracic procedure from March 2012 to April 2014 and required suction postoperatively for air leak were included in the study. Patients were identified as suitable according to the discharge criteria. Data regarding patient demographics were collected prospectively on the thoracic database, and data on the drainage device were logged in a specific data sheet. Visits to the follow-up clinic were also recorded.

RESULTS

During the study period, 50 patients stayed a total 1125 days on the portable suction system. Twenty were discharged home, equating to 772 bed-days saved (GBP 270,000 cost-saving). Clinic attendance totalled 162 visits (GBP 24,300 cost reimbursement for attendance). Six (30%) patients were readmitted on 9 occasions due to device malfunction or inability to cope at home.

CONCLUSION

Careful identification of patients suitable for discharge with a portable suction device achieved a significant cost-saving and freed hospital beds, thus allowing increased surgical activity. Patients were also able to be cared for within their home environment and maintain their quality of life.

Severe antiphospholipid syndrome and cardiac surgery: Perioperative management

Antiphospholipid syndrome is an antiphospholipid antibody-mediated prothrombotic state leading to arterial and venous thrombosis. This condition alters routine in-vitro coagulation tests, making results unreliable. Antiphospholipid syndrome patients requiring cardiac surgery with cardiopulmonary bypass present a unique challenge in perioperative anticoagulation management. We describe 3 patients with antiphospholipid syndrome who had successful heart valve surgery at our institution. We have devised an institutional protocol for antiphospholipid syndrome patients, and all 3 patients were managed according to this protocol. An algorithm-based approach is recommended because it improves team work, optimizes treatment, and improves patient outcome.

Preoperative assessment of lung cancer patients: Evaluating guideline compliance (re-audit)

Background

Guidelines have been issued for the management of lung cancer patients in the United Kingdom. However, compliance with these national guidelines varies in different thoracic units in the country. We set out to evaluate our thoracic surgery practice and compliance with the national guidelines.

Methods

An initial audit in 2011 showed deficiencies in practice, thus another audit was conducted to check for improvements in guideline compliance. A retrospective study was carried out over a 12-month period from January 2013 to January 2014 and included all patients who underwent radical surgical resection for lung cancer. Data were collected from computerized records.

Results

Sixty-eight patients had radical surgery for lung cancer between January 2013 and January 2014. Four patients were excluded from the analysis due to incomplete records. Our results showed improvements in our practice compared to our initial audit. More patients underwent surgery within 4 weeks of computed tomography and positron-emission tomography scanning. An improvement was noticed in carbon monoxide transfer factor measurements. Areas for improvement include measurement of carbon monoxide transfer factor in all patients, a cardiology referral in patients at risk of cardiac complications, and the use of a global risk stratification model such as Thoracoscore.

Conclusion

Guideline-directed service delivery provision for lung cancer patients leads to improved outcomes. Our results show improvement in our practice compared to our initial audit. We aim to liaise with other thoracic surgery units to get feedback about their practice and any audits regarding adherence to the British Thoracic Society and National Institute for Health and Care Excellence guidelines.

Wide field-of-view on-chip Talbot fluorescence microscopy for longitudinal cell culture monitoring from within the incubator

Time-lapse or longitudinal fluorescence microscopy is broadly used in cell biology. However, current available time-lapse fluorescence microscopy systems are bulky and costly. The limited field-of-view (FOV) associated with the microscope objective necessitates mechanical scanning if a larger FOV is required. Here we demonstrate a wide FOV time-lapse fluorescence self-imaging Petri dish system, termed the Talbot Fluorescence ePetri, which addresses these issues. This system's imaging is accomplished through the use of the Fluorescence Talbot Microscopy (FTM). By incorporating a microfluidic perfusion subsystem onto the platform, we can image cell cultures directly from within an incubator. Our prototype has a resolution limit of 1.2 μm and an FOV of 13 mm(2). As demonstration, we obtained time-lapse images of HeLa cells expressing H2B-eGFP. We also employed the system to analyze the cells' dynamic response to an anticancer drug, camptothecin (CPT). This method can provide a compact and simple solution for automated fluorescence imaging of cell cultures in incubators.

Chronic percutaneous gallstone discharge following videothoracoscopic decortication

Computed tomographic imaging is not recommended as an essential prerequisite in surgery for pleuro-pulmonary sepsis in the current guidelines. We highlight one consequent pitfall and its sequelae. We report the discharge of gallstones through a healed intercostal drain site four months following video-assisted thoracic surgery for early pleural empyema secondary to missed calculous gallstone disease. The importance of awareness and a high index of suspicion to diagnose the underlying extra-thoracic cause of a right-sided pleural collection in a patient with a previous history of gallstone disease cannot be overemphasised.

Improved reliability of post-operative ventricular pacing by use of bipolar temporary pacing leads

The study compared the clinical reliability of using a bipolar epicardial wire (6495, Medtronic) over a unipolar type (FEP15, Ethicon) for post-operative pacing in coronary artery surgery. Atrial and ventricular wires of both types were implanted in 18 patients. Sensitivities and pacing thresholds were tested for 5 consecutive days. Results show that pacing thresholds were better maintained with the bipolar wire in both atria and ventricles. However, sensing failures were frequent in the atrial position (34% vs 9.3% compared with unipolar). By contrast, in the ventricle, no sensing failures occurred (0% vs 17.6% compared with unipolar). Furthermore, sensing magnitude was significantly better (11.13+/-1.32 vs 5.65+/-0.53 mV, P<0.001). We conclude that a single 6495 bipolar wire is effective for temporary ventricular pacing, whilst double unipolar wires remain a useful strategy for securing atrial sensing and pacing.

Hybrid management of coronary artery disease and coarctation of aorta

The treatment of coarctation of aorta with an additional cardiac lesion in adults remains a difficult surgical challenge. We present here an alternative, two-stage, hybrid approach that combined stent repair of aortic coarctation followed by coronary artery bypass operation in an adult with critical coronary lesions and a poor ventricle. This method may be a potentially useful strategy in reducing the comorbidity of operation to both lesions.

Optic axons regenerate into sciatic nerve isografts only in the presence of Schwann cells

Optic axons regenerate into normal but not acellular peripheral nerve (PN) grafts. The first axons penetrate the PN graft before 5 days and grow inside the basal lamina tubes amongst the Schwann cells. By 30 days, 4% of the surviving retinal ganglion cells (RGC) regenerate axons for at least 10 mm into the PN graft. Laminin rich basal lamina tubes persist in the acellular PN transplants but only a few axons penetrate the most proximal parts of the tubes by 5 days and none grow farther into the graft by 30 days. RGC counts demonstrate that 34% of the normal RGC population survive 30 days after anastomosing a normal PN to the transected optic nerve. After anastomosing acellular PN grafts, 25% of RGCs survive compared with 10% after optic nerve section. These findings demonstrate that laminin does not promote regeneration of axons and that Schwann cells play the primary role of offering trophic support and even a substrate for growth. RGC survival is also enhanced by PN grafts even when Schwann cells are absent. This latter result suggests that RGC survival is promoted by a trophic substance released from axons and/or Schwann cells in the PN grafts which survives the thawing/freezing procedure (used to kill the Schwann cells) and is active in the grafts in the immediate post operative period.