In patients undergoing dialysis who require a valve replacement is a bioprosthetic valve superior to a mechanical prosthesis in terms of long-term survival and morbidity?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'In [dialysis patients undergoing a valve replacement] is [a bioprosthetic valve superior to a mechanical prosthesis] for [long-term survival and morbidity]'. Altogether more than 501 papers were found using the reported search, of which five represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. There was limited high-quality evidence with all studies being retrospective. One meta-analysis and four cohort studies provided the evidence that there was no significant difference in long-term survival based on prosthesis type. However, the majority of studies demonstrated a significantly higher rate of valve-related complications including bleeding and thromboembolism, and readmission to hospital in the mechanical valve prosthesis group, likely related to the requirement for long-term anticoagulation. We conclude that overall long-term survival in dialysis-dependent patients is poor. While prosthesis type does not play a significant contributing role to long-term survival, bioprosthetic valves were associated with significantly fewer valve-related complications. Based on the available evidence, a bioprosthetic valve may be more suitable in this high-risk group of patients as it may avoid the complications associated with long-term anticoagulation without any reduction in long-term survival.

Operative Results of Mitral Valve Repair and Replacement in Chronic Ischaemic Mitral Valve Regurgitation.

BACKGROUND: Ischaemic mitral regurgitation (IMR) carries significant morbidity and mortality. Surgical management includes coronary artery bypass surgery alone or concomitant with mitral valve repair or replacement. There is ongoing debate regarding the appropriate approach to the mitral valve in relation to long-term outcomes. This review examines our early and late follow-up, with operative and echocardiographic outcomes for mitral valve repair and mitral replacement for chronic IMR. METHODS: A retrospective review was performed on prospectively collected data of 119 consecutive patients who either underwent mitral repair (n=101) or mitral replacement (n=18) for chronic IMR at Prince Henry and The Prince of Wales hospitals in Sydney between 1999-2016. All patients had pre and postoperative transthoracic echocardiograms. Follow-up echocardiographic data was obtained from the most recent clinical appointment. Follow-up mortality outcomes were obtained with ethics approval from the Australian National Death Index (NDI). RESULTS: There was no statistical difference between cardiopulmonary bypass (CPB) time, cross-clamp time, time spent in intensive care unit (ICU) and time to discharge between cohorts. The replacement cohort was noted to have higher preoperative pulmonary artery (PA) pressures and a higher severity of IMR. Seven (7) deaths were in the mitral valve (MV) repair group within 30 days (6.9%) and three deaths in the MV replacement group within 30 days (16.7%). Echocardiographic follow-up was complete in 78% of the MV repair cohort at an average of 4.06±2.66 years, and 73% complete in the MV replacement cohort at an average of 6.09±4.3 years. Three (3) patients had prior MV repair before MV replacement early at days zero and 17, and late at 8 years respectively. Follow-up echocardiography showed mitral regurgitation (MR) in the mitral valve repair cohort as ≤ mild in 83.5% and ≤ trivial in 35.6%. In the MV replacement cohort MR ≤ mild in 100% and ≤ trivial in 82% with no moderate or severe MR. Preoperative tricuspid regurgitation (TR) and a flexible annuloplasty were predictive of an MR grade > mild in the repair cohort at discharge. Five-year (5-year) survival for the repair cohort was 85% with a mean follow-up time of 7.1±3.83 years. For the replacement cohort, five-year survival was 77.8% with a mean follow-up time of 5.35±1.54 years. CONCLUSIONS: Mitral valve repair and replacement for chronic IMR has acceptable mortality, reintervention rates and excellent postoperative echocardiographic degrees of IMR in this cohort. Further evaluation is required into quality of life post intervention for IMR and of preoperative predictive factors of significant MR postoperatively to help guide the appropriate choice of treatment. The presence of preoperative tricuspid regurgitation of moderate grade or higher, and the use of a flexible annuloplasty may indicate patients more likely to have a higher grade of MR at follow-up following mitral valve repair in patients with IMR.

Cluster of invasive Mycobacteria chimaera infections following cardiac surgery demonstrating novel clinical features and risks of aortic valve replacement.

There is a global outbreak of infections due to Mycobacterium chimaera associated with cardiac surgery. The most serious infections involve prosthetic material implantation, and all have followed surgical procedures involving cardiopulmonary bypass. We describe a cluster of four cases following cardiac surgery at a tertiary referral centre in Sydney, Australia. We report novel clinical findings, including haemolysis and kidney rupture possibly related to immune reconstitution inflammatory syndrome. The positive effect of corticosteroids on haemodynamic function in two cases and the failure of currently recommended antimicrobial therapy to sterilise prosthetic valve material in the absence of surgery despite months of treatment are also critically examined. Positron emission tomography was positive in two cases despite normal transoesophageal echocardiograms. The proportion of cases with M. chimaera infection after aortic valve replacement (4/890, 0.45%; 95% confidence interval 0.18-1.15%) was significantly higher than after all other cardiothoracic surgical procedures (0/2433, 0%; 95% confidence interval 0-0.16%).

Phaeochromocytoma presenting with labile blood pressures following coronary artery bypass grafting.

Pheochromocytomas have been reported prior to and during coronary artery bypass surgery. We present a patient with an undiagnosed pheochromocytoma who presented with labile hypertension following coronary artery bypass surgery. This case calls attention to the inclusion of an undiagnosed pheochromocytoma in the differential diagnosis for all patients who develop labile hypertension in the postoperative period following cardiac surgery.

Surgical Management of Malignant Pleural Mesothelioma: An Update of Clinical Evidence.

To investigate the surgical management of malignant pleural mesothelioma, 2 randomized controlled trials have been completed. We discuss the findings from these trials and the current evidence of various surgical techniques to treat this challenging disease.

A case of spontaneous chylous pericardial effusion in Poland syndrome.

Chylous pericardial effusion is an uncommon entity that is most commonly associated with post-cardiac surgery, in particular aortic valve and minimally invasive cardiac surgery. Post-radiation therapy, infection, mediastinal neoplasm, lymphoma and a small group of idiopathic, spontaneous chylous pericardial effusion have also been reported as the causes. Here, we report a rare case of pericardial effusion secondary to chylous fistula in a 63-year-old man with Poland syndrome. The case highlights an unusual thoracic duct anomaly as a cause of our reported chylous pericardial effusion.

Drug eluting stent induced coronary artery aneurysm repair by exclusion. Where are we headed?

We present a case of left anterior descending (LAD) coronary artery aneurysm at the site of previous stent placement 3 years previously. The patient presented with recent worsening of angina. Angiography and 64 slice CT angiography confirmed the presence of 6mm aneurysm of LAD at the site of previous stent involving the origin of diagonal, with thrombus proximal and distal to the stent. This patient was successfully managed by taking the posterior wall of the anterior descending artery while suturing the heel of the left internal mammary artery (LIMA)-LAD anastomosis. The idea was to create severe stenosis upstream to prevent distal embolisation from the site of aneurysm. The diagonal was grafted with a saphenous venous graft. Follow-up angiogram at 3 months demonstrated successful exclusion of the aneurysm and unobstructed flow through the grafts.

Homograft aortic valve replacement--the experience of one unit.

BACKGROUND: Homograft valves offer advantages including avoidance of anticoagulation and less susceptibility to infection especially in the setting of endocarditis. However, there is concern about their durability and possible accelerated degeneration particularly in cases of second time replacement with homografts. AIM: This study aimed to evaluate the pattern of homograft failure and the quality of life in patients after homograft implantation. METHODS: Between 1990 and 1998, 58 patients underwent aortic valve replacement with a homograft (aortic homograft = 47, pulmonary homograft = 11). Evaluation was based on clinical and echocardiographic examination, patient questionnaires and explanted valve pathology. Survival and freedom from cardiac related death were expressed by actuarial methods. RESULTS: Follow up ranged from 1 to 10 years (mean 5.5 years). Analysis of questionnaires revealed 60% of respondents to be in good performance status and 20% in moderate and 20% in poor performance status groups. Eleven patients (18.9%) required subsequent redo valve replacement after initial homograft insertion (pulmonary = 6, aortic = 5) due to either valve dehiscence (n=4) or valve degeneration (n=7). The mean interval of re-replacement was 5.4 years. CONCLUSIONS: Pulmonary homografts have a high failure rate in the aortic position. Overall subjective and clinical improvement after surgery is less than expected for a "physiological" device. In the setting of low availability of homografts the use of off-the-shelf devices such as stentless xenografts may be preferable in most cardiac surgical units in the current era.