Mycotic Pseudoaneurysms of the Coronary Arteries.

BACKGROUND: Mycotic coronary artery aneurysms are rare and are often fatal without early recognition and prompt surgical management. METHODS: We present a case of mycotic pseudoaneurysm of the left main coronary artery (LMCA) after disseminated methicillin-sensitive Staphylococcus aureus (MSSA) bacteraemia. A review of the literature in regards to the surgical management of coronary artery mycotic pseudoaneurysms was conducted. RESULTS: There were 26 reported cases of surgical management of coronary artery mycotic pseudoaneurysms. Coronary artery bypass surgery (CABG) and excision was the most common management (73.1% of cases reviewed). CONCLUSION: This case highlights the difficultly in diagnosing mycotic coronary artery pseudoaneurysms.

Heart-Lung Transplantation: Technical Modifications to Simplify the Procedure.

Heart-lung transplantation is a mature therapy but has perioperative complications, such as phrenic nerve dysfunction and mediastinal bleeding. We report our technical modifications to simplify the procedure.

Extracorporeal Membrane Oxygenation as a Bridge to Surgical Repair of Postinfarct Ventricular Septal Defect.

Postinfarct ventricular septal defect (PIVSD) is associated with high mortality and the management of these patients has been a challenge with little improvement in outcomes. We commenced a protocol of veno-arterial extracorporeal membrane oxygenation (VA ECMO) for those patients who present in cardiogenic shock with the aim to improve end-organ function before definitive surgical repair to reduce postoperative mortality. This study reviewed the results of this strategy. This was a single-center, retrospective review of all patients who were admitted to our institution with PIVSD in cardiogenic shock from September 2015 to November 2019. Clinical and investigative data were evaluated. Eight patients were referred with PIVSD during this period in cardiogenic shock. One patient had an anterior PIVSD and the other seven had inferior PIVSD. Six patients underwent surgical repair at a median (interquartile range, IQR) of 7 (5-8) days after initiation of VA ECMO. Two patients did not undergo surgical repair. Five patients survived after surgery and one patient died postoperatively due to multiorgan failure. Preoperative use of VA ECMO is a feasible strategy for PIVSD and may improve the results of repair.

Australian experience with VAD as a bridge to paediatric cardiac transplantation.

The Royal Children's Hospital, Melbourne is the National Paediatric Heart Transplant Centre of Australia. A variety of ventricular assist devices (VADs) have been used effectively as a bridge to heart transplantation in adult patients, however, the experience in the paediatric population is limited. We present our initial experience using the Thoratec and Medos VAD systems as a bridge to heart transplantation in the designated centre for paediatric cardiac transplantation in Australia. The medical records of all patients supported with a Thoratec or Medos VAD at the RCH from July 2005 to July 2007 were retrospectively reviewed. Seven patients between 5 and 16 years of age were supported with the Thoratec or Medos VAD during the period of study. All of the patients were supported with a left sided ventricular assist device (LVAD). The length of time supported ranged from 6 to 230 days, with a median of 22 days. Co-morbidities included surgical re-exploration for bleeding, cannula site wound infections and thromboembolic events. Two patients died before a donor heart became available. From our limited experience, the use of a VAD as a bridge to heart transplantation is a feasible option for children with end stage cardiac failure.

Characterization of infected, explanted ventricular assist device drivelines: The role of biofilms and microgaps in the driveline tunnel.

BACKGROUND: Driveline infections remain a major complication of ventricular assist device (VAD) implantation. This study aimed to characterize in vivo microbial biofilms associated with driveline infections and host tissue integration of implanted drivelines. METHODS: A total of 9 infected and 13 uninfected drivelines were obtained from patients with VAD undergoing heart transplantation in Australia between 2016 and 2018. Each driveline was sectioned into 11 pieces of 1.5 cm in length, and each section was examined by scanning electron microscopy (SEM) and viable counts for microbial biofilms. Microorganisms were cultured and identified. Host tissue integration of clinical drivelines was assessed with micro-computed tomography (CT) and SEM. An in vitro interstitial biofilm assay was used to simulate biofilm migration in the driveline tunnel, and time-lapse microscopy was performed. RESULTS: Of the 9 explanted, infected drivelines, all had organisms isolated from varying depths along the velour section of the drivelines, and all were consistent with the swab culture results of the clinically infected exit site. SEM and micro-CT suggested insufficient tissue integration throughout the driveline velour, with microgaps observed. Clinical biofilms presented as microcolonies within the driveline tunnel, with human tissue as the sub-stratum, and were resistant to anti-microbial treatment. Biofilm migration mediated by a dispersal-seeding mechanism was observed. CONCLUSIONS: This study of explanted infected drivelines showed extensive anti-microbial-resistant biofilms along the velour, associated with microgaps between the driveline and the surrounding tissue. These data support the enhancement of tissue integration into the velour as a potential preventive strategy against driveline infections by preventing biofilm migration that may use microgaps as mediators.

A donor PaO2/FiO2 < 300 mm Hg does not determine graft function or survival after lung transplantation.

BACKGROUND: A donor arterial PO2/FiO2 (P/F ratio) of less than the 300 threshold would frequently result in either exclusion of the donor or placement of the lungs on ex vivo lung perfusion (EVLP). The aim was to investigate the veracity of the P/F ratio threshold of 300 for donor lung acceptability. METHODS: In 93 brain dead lung donors, arterial blood gases were drawn in the intensive care unit (ICU) just before procurement and each of the 4 donor pulmonary veins in the operating room (OR). No donor lungs were rejected for transplantation based on the last ICU or OR P/F ratio, and EVLP was not used. The recipients were followed up 6 and 12 months following transplantation. RESULTS: There were 93 recipients of bilateral lung transplantation. An arterial P/F ratio of < 300 was largely driven by a low P/F ratio in the lower lobes. There were no differences between the recipients receiving donor lungs where the ICU P/F ratio was < 300 compared with ≥ 300 in the time to extubation, grade of primary graft dysfunction, pulmonary function at 6 and 12 months, and 12-month survival. CONCLUSIONS: From this study:(1) If a donor P/F threshold of 300 was adhered to, 36% would have been rejected, and (2) The donor P/F ratio threshold of 300 is excessively conservative and results in the wastage of donor lungs and the application of unnecessary EVLP.

A Phase 1 Study of a Novel Bidirectional Perfusion Cannula in Patients Undergoing Femoral Cannulation for Cardiac Surgery.

OBJECTIVE: Leg ischemia is a serious complication of femoral artery cannulation. The primary aim of this study was to assess the safety and efficacy of a novel bidirectional femoral arterial cannula (Sorin Group USA, a wholly owned subsidiary of LivaNova PLC, Arvada, CO USA) that provides both antegrade and retrograde flow, in patients undergoing peripheral cannulation for cardiopulmonary bypass during cardiac surgery. METHODS: Patients undergoing routine cardiac surgery requiring femoral artery cannulation for cardiopulmonary bypass were identified preoperatively. Informed written consent was obtained in all cases. Bidirectional cannula insertion used either a surgical cut-down and wire through needle approach or a percutaneous technique. Flow in the superficial femoral artery was assessed using Doppler ultrasound after commencement of cardiopulmonary bypass. Lower limb perfusion was assessed using reflectance near-infrared spectroscopy to measure regional oxygen saturations in the cannulated limb during cardiopulmonary bypass. RESULTS: Fifteen patients (median age = 61.3 years, range = 26-79 years, 10 males, 5 females) underwent femoral arterial cannulation using the novel bidirectional femoral cannula between August 2016 and May 2017. Fourteen cannulae were inserted directly into the femoral artery via a surgical cut-down and wire through needle technique. One bidirectional cannula was inserted using a percutaneous insertion technique. Indications included minimally invasive mitral and aortic valve surgery, thoracic aortic aneurysm repair, and redo cardiac surgery. The median duration of cardiopulmonary bypass was 129 minutes (range = 53-228 minutes). The cannula was inserted and positioned without difficulty in 14 of 15 patients. Incorrect sizing and arterial spasm prevented correct cannula positioning in one patient. Antegrade flow in the superficial femoral artery was observed on Doppler ultrasound in 12 of 12 patients in which this was performed. Continuous stable distal perfusion was demonstrated in the cannulated limb in 14 of 15 patients. No procedural complications occurred in the immediate or convalescent postoperative period. CONCLUSIONS: This study demonstrates that in patients undergoing femoral arterial cannulation for cardiopulmonary bypass during cardiac surgery, the use of a novel bidirectional cannula is safe and easy to insert and provides stable distal perfusion of the cannulated limb. Use of the device should largely obviate the need to insert a separate downstream perfusion cannula or use other techniques to protect against lower limb ischemia. Further research on a larger scale and in different patient populations is now warranted.

Is informed consent in cardiac surgery and percutaneous coronary intervention achievable?

BACKGROUND: Medical and legal published work regularly discusses informed consent and patient autonomy before medical interventions. Recent discussions have suggested that Cardiothoracic surgeons' risk adjusted mortality data should be published to facilitate the informed consent process. However, as to which aspects of medicine, procedures and the associated risks patients understand is unknown. It is also unclear how well the medical profession understands the concepts of informed consent and medical negligence. The aims of this study were to evaluate patients undergoing coronary artery bypass surgery (CABG) and percutaneous coronary intervention (PCI) to assess their understanding of the risks of interventions and baseline level of understanding of medical concepts and to evaluate the medical staff's understanding of medical negligence and informed consent. METHODS: Patients undergoing CABG or PCI at a tertiary hospital were interviewed with questionnaires focusing on the consent process, the patient's understanding of CABG or PCI and associated risks and understanding of medical concepts. Medical staff were questioned on the process of obtaining consent and understanding of medicolegal concepts. RESULTS: Fifty CABG patients, 40 PCI patients and 40 medical staff were interviewed over a 6-month period. No patient identified any of the explained risks as a reason to reconsider having CABG or PCI, but 80% of patients wanted to be informed of all risks of surgery. 80% of patients considered doctors obligated to discuss all risks of surgery. One patient (2%) expressed concern at the prospect of a trainee surgeon carrying out the operation. Stroke (40%) rather than mortality (10%) were the important concerns in patients undergoing CABG and PCI. The purpose of interventions was only partially understood by both groups; PCI patients clearly underestimated the subsequent need for repeat PCI or CABG. Knowledge of medical concepts was poor in both groups: less than 50% of patients understood the cause or consequence of an AMI or stroke and less than 20% of patients correctly identified the ratio equal to 0.5%. One doctor (2.5%) correctly identified the four elements of negligence, eight (20%) the meaning of material risk and four (10%) the meaning of causation. Thirty doctors (75%) believed that all complications of a procedure needed to be explained for informed consent. Less than 10% could recognize landmark legal cases. CONCLUSION: Patients undergoing both CABG and PCI have a poor understanding of their disease, their intervention, and its complications making the attaining of true informed consent difficult, despite their desire to be informed of all risks. PCI patients particularly were highly optimistic regarding the need for reintervention over time, which requires specific attention during the consent process. Medical staff showed a poor knowledge of the concepts of material risk and medical negligence requiring much improved education of both junior doctors and specialists.

First clinical implant of the VentrAssist left ventricular assist system as destination therapy for end-stage heart failure.

The VentrAssist device left ventricular assist system, designed for permanent implantation, is a novel centrifugal pump with a hydrodynamically suspended rotor. The first human implant was into a 72-year-old man with New York Heart Association (NYHA) class IV heart failure due to idiopathic dilated cardiomyopathy. The implant and recovery were uneventful, and the patient survives at 17 months, is NYHA class II, and lives at home. This device shows promise in end-stage heart failure for permanent implantation and bridge to transplantation.

Occlusive wrap dressing reduces infection rate in saphenous vein harvest site.

BACKGROUND: Infection in the saphenous vein harvest site is a common problem. We developed an occlusive circumferential wrap dressing technique that reduces skin edge tension, eliminates dead space, and prevents external contamination. We compared the surgical site infection rate using the wrap dressing technique with that of standard longitudinal dressings. METHODS. One hundred fifty-two consecutive patients were randomly assigned to receive either standard dressings or the wrap dressing. Data were collected in the hospital and then 4 to 6 weeks postoperatively. Superficial and deep wound infections were defined by the standard criteria from the Centers for Disease Control and Prevention. RESULTS: The infection rate in the wrap group was 14% compared with 35%, for the standard group (p = 0.006). Multivariate analysis showed that wrap technique was the only significant predictor (negative) of infection (odds ratio, 0.19; p = 0.001). CONCLUSIONS: In saphenous vein harvest wounds, the occlusive wrap dressing technique has the potential to reduce the rate of infection by 50%. This simple and inexpensive technique is also readily applicable to the radial artery harvest site in the arm and may provide similar benefit.

Carbon dioxide insufflation in open-chamber cardiac surgery: a double-blind, randomized clinical trial of neurocognitive effects.

OBJECTIVE: The aims of this study were first to analyze neurocognitive outcomes of patients after open-chamber cardiac surgery to determine whether carbon dioxide pericardial insufflation reduces incidence of neurocognitive decline (primary end point) as measured 6 weeks postoperatively and second to assess the utility of carbon dioxide insufflation in cardiac chamber deairing as assessed by transesophageal echocardiography. METHODS: A multicenter, prospective, double-blind, randomized, controlled trial compared neurocognitive outcomes in patients undergoing open-chamber (left-sided) cardiac surgery who were assigned carbon dioxide insufflation or placebo (control group) in addition to standardized mechanical deairing maneuvers. RESULTS: One hundred twenty-five patients underwent surgery and were randomly allocated. Neurocognitive testing showed no clinically significant differences in z scores between preoperative and postoperative testing. Linear regression was used to identify factors associated with neurocognitive decline. Factors most strongly associated with neurocognitive decline were hypercholesterolemia, aortic atheroma grade, and coronary artery disease. There was significantly more intracardiac gas noted on intraoperative transesophageal echocardiography in all cardiac chambers (left atrium, left ventricle, and aorta) at all measured times (after crossclamp removal, during weaning from cardiopulmonary bypass, and at declaration of adequate deairing by the anesthetist) in the control group than in the carbon dioxide group (P < .04). Deairing time was also significantly longer in the control group (12 minutes [interquartile range, 9-18] versus 9 minutes [interquartile range, 7-14 minutes]; P = .002). CONCLUSIONS: Carbon dioxide pericardial insufflation in open-chamber cardiac surgery does not affect postoperative neurocognitive decline. The most important factor is atheromatous vascular disease.

Skeletonized internal thoracic artery harvesting reduces chest wall dysesthesia after coronary bypass surgery.

OBJECTIVE: A pain syndrome related to intercostal nerve injury during internal thoracic artery harvesting causes significant morbidity after coronary bypass surgery. We hypothesized that its incidence and severity might be reduced by using skeletonized internal thoracic artery harvesting rather than pedicled harvesting. METHODS: In a prospective double-blind clinical trial, 41 patients undergoing coronary bypass were randomized to receive either unilateral pedicled or skeletonized internal thoracic artery harvesting. Patients were assessed 7 (early) and 21 (late) weeks postoperatively with reproducible sensory stimuli used to detect chest wall sensory deficits (dysesthesia) and with a pain questionnaire used to assess neuropathic pain. RESULTS: At 7 weeks postoperatively, the area of harvest dysesthesia (percentage of the chest) in the skeletonized group (n = 21) was less (median, 0%; interquartile range, 0-0) than in the pedicled group (n = 20) (2.8% [0-13], P = .005). The incidence of harvest dysesthesia at 7 weeks was 14% in the skeletonized group versus 50% in the pedicled group (P = .02). These differences were not sustained at 21 weeks, as the median area of harvest dysesthesia in both groups was 0% (P = .89) and the incidence was 24% and 25% in the skeletonized and pedicled groups, respectively (P = 1.0). The incidence of neuropathic pain in the skeletonized group compared with the pedicled group was 5% versus 10% (P = .6) at 7 weeks and 0% versus 0% (P = 1.0) at 21 weeks. CONCLUSIONS: Compared with pedicled harvesting, skeletonized harvesting of the internal thoracic artery provides a short-term reduction in the extent and incidence of chest wall dysesthesia after coronary bypass, consistent with reduced intercostal nerve injury and therefore the reduced potential for neuropathic chest pain.

Long-term outcomes of cadaveric lobar lung transplantation: helping to maximize resources.

BACKGROUND: Cadaveric lobar lung transplantation (CLLTx) represents a potential opportunity to address the bias against smaller recipients, especially children, on transplant waiting lists. The widespread use of CLLTx is hindered by the paucity of outcome data with respect to early complications and long-term lung function and survival. METHODS: We looked at the long-term outcomes in 9 patients undergoing CLLTx since May 2003, including early surgical complications, pulmonary function tests, and survival. Patients were analyzed by whether the decision to perform CLLTx was elective (made at the time of listing) or emergent (surgical decision). RESULTS: The incidence of early complications in the entire group was low, with the most common being atrial arrhythmias and prolonged thoracostomy tube. Lung function at 1 and 2 years (mean forced expiratory volume in 1 second % predicted +/- standard deviation of 73 +/- 18 and 60.5 +/- 27, respectively) was equivalent to living lobar transplant results. Overall survival was similar to 199 patients who received conventional cadaveric LTx during the same period. CONCLUSION: This study suggests that CLLTx has a low complication rate with acceptable lung function and long-term survival, especially in cases where consideration has been given to CLLTx at the time of listing. CLLTx warrants consideration more often for patients of smaller physique to improve their chance of receiving LTx.

Recovery from anthracycline cardiomyopathy after long-term support with a continuous flow left ventricular assist device.

We report the clinical course of a 16-year-old girl in remission from non-Hodgkin's lymphoma who presented in cardiogenic shock due to a severe anthracycline cardiomyopathy. The patient was initially stabilized using central extracorporeal membrane oxygenation support, followed by conversion to a left ventricular assist device. Unexpected evidence of cardiac recovery 9 months after implant enabled device weaning during a 3-month period, culminating in successful device explantation 1 year after implant. The patient survives 18 months after explant in New York Heart Association class I, on conventional heart failure medical management and metabolic therapy.

Initial clinical experience with the VentrAssist left ventricular assist device: the pilot trial.

BACKGROUND: The VentrAssist (VA) is a novel, continuous flow left ventricular assist device (LVAD). The purpose of this trial was to investigate the safety and efficacy of the VA in elderly patients with end-stage heart failure. METHODS: In this prospective trial, patients requiring circulatory support either as destination therapy (DT) or as a bridge to transplant (BTT) were implanted with a VA device. RESULTS: Between June 2003 and August 2006, 9 elderly patients (mean age 65 years) were implanted. The median support time was 454 (range 73 to 977) days for the DT and 35 (range 26 to 508) days for the BTT cohort. All patients survived implantation; 30-day mortality was 22% (n = 2). The adverse event profile was encouraging, with no embolic neurologic events and minimal sepsis. Cumulative trial support time was 7.3 patient-years. CONCLUSIONS: The VentrAssist shows promise as a safe and reliable "third-generation" VAD. Having demonstrated potential as a DT and prolonged BTT device, extended clinical trials are warranted.

Pediatric experience with the VentrAssist LVAD.

PURPOSE: The purpose of this study is to describe the first experience of implanting a new left ventricular assist device in pediatric patients with end-stage heart failure. DESCRIPTION: In two recent prospective, international, multicenter clinical trials, three children (aged

Fast-track cardiac surgery: application in an Australian setting.

In response to the current state of healthcare in Australia, our unit has employed a fast-track policy for low-risk cardiac surgery patients since January 2000. This study was designed to examine the safety and efficacy of this policy. From July 2001 to June 2004, 342 (23%) of 1,488 patients undergoing cardiac surgery were identified preoperatively as suitable for fast-track recovery. There was a significantly shorter median time to extubation (4 hr vs 9 hr), reduced intensive care unit stay (8 hr vs 26 hr), and a lower rate of readmission to the intensive care unit (0.6% vs 4.2%) for those fast tracked compared to the other patients. The fast-track group had a lower incidence of complications and significantly decreased median length of hospital stay (5 vs 7 days). We concluded that this policy accurately identifies the low-risk cardiac surgery patients suitable for less intensive postoperative recovery.

Prolonged cardiac allograft ischemic time--no impact on long-term survival but at what cost?

INTRODUCTION: The aim of this paper was to review the outcomes of cardiac transplantation with regards to short- and long-term survival, focusing particularly on patients who receive organs with long ischemic times and the resource utilization necessary to support such patients through their postoperative period. METHODS: A retrospective review of 420 consecutive cardiac transplants in a single institution was undertaken. RESULTS: The five- and 10-yr survival rates for the entire group were 0.76 (95% CI: 0.72-0.80) and 0.60 (0.54-0.66). There was no decrease in mid- or long-term survival in patients who received organs with ischemic times over 300 min. Longer donor organ ischemic time was not associated with increased 30 d mortality but was significantly associated with longer intensive care bed stay, increased incidence of primary graft failure, need for mechanical support, and complications such as acute renal failures. CONCLUSIONS: Although using donor organs with longer ischemic times for cardiac transplantation does not impact on survival, there is a significantly increased utilization of resources to ensure these patients survive the postoperative period.

Successful left ventricular assist device bridge to transplantation after failure of a fontan revision.

A Fontan operation will eventually fail in many patients. Fontan conversion to extracardiac conduit has been recommended but is not always successful. We present a case of a patient who went into intractable heart failure after reoperation, was rescued by left ventricular assist device implantation, and was finally bridged to heart transplantation.