Isolated Tricuspid Valve Surgery: The Auckland Experience 2011-2019.

INTRODUCTION: Isolated tricuspid valve surgery is an uncommon operation. Historical reports, including a previous review from our unit, demonstrated high morbidity and mortality associated with this operation. Many of these patients had severely impaired right ventricular function at the time of the surgery. Since our previous review, we have actively encouraged our local cardiologists to refer patients with severe isolated tricuspid disease for surgery before right ventricular remodelling occurs. This present study was performed to assess our current results. MATERIAL AND METHODS: A prospectively-maintained hospital database was used to identify all adult non-congenital patients receiving standalone tricuspid valve repair or replacement at New Zealand's largest cardiothoracic surgical unit from July 2011 to July 2019. Additional demographic and clinical data were collected by review of patient electronic records. RESULTS: During the 8-year study period, a total of 50 patients underwent isolated tricuspid valve surgery. Most patients were operated on for functional (40%) or rheumatic (30%) tricuspid disease. The majority of patients underwent surgery when the right ventricular function preoperatively was normal (30%) or mildly/moderately impaired (60%). Over half the patient sample (56%) underwent valve replacement. The 30-day mortality rate and stroke rate were 6% and 2% respectively. The medium-term survival was 80% at 4 years mean follow-up. CONCLUSION: Isolated tricuspid surgery is no longer a high mortality operation when it is performed on patients who have preserved right ventricular function.

Chronic thromboembolic pulmonary hypertension in Australia and New Zealand: An analysis of the PHSANZ registry.

BACKGROUND AND OBJECTIVE: Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious condition occurring in 2%-4% of patients after acute pulmonary embolism. Pulmonary endarterectomy (PEA) is a potential cure for technically operable disease. The epidemiology and long-term outcomes of CTEPH have not been previously described in Australia and New Zealand. METHODS: Data were extracted from the Pulmonary Hypertension Society of Australia and New Zealand (PHSANZ) registry for patients diagnosed with CTEPH between January 2004 and March 2020. Baseline characteristics, treatment strategies, outcome data and long-term survival are reported. RESULTS: A total of 386 patients were included with 146 (37.8%) undergoing PEA and 240 (62.2%) in the non-PEA group. PEA patients were younger (55 ± 16 vs. 62 ± 16 years, p < 0.001) with higher baseline 6-min walk distance (6MWD; 405 ± 122 vs. 323 ± 146 m, p = 0.021), whilst both groups had similar baseline pulmonary haemodynamics. Pulmonary hypertension-specific therapy was used in 54% of patients post-PEA and 88% in the non-PEA group. The 1-, 3- and 5-year survival rates were 93%, 87% and 84% for the PEA group compared to 86%, 73% and 62%, respectively, for the non-PEA group (p < 0.001). Multivariate survival analysis showed baseline 6MWD was an independent predictor of survival in both operated and medically managed patients. CONCLUSION: In this first multicentre report of CTEPH in Australia and New Zealand, long-term survival is comparable to that in other contemporary CTEPH registries. However, PEA was only performed in a minority of CTEPH patients (37.8%) and significantly less than overseas reports. Greater awareness of PEA and improved patient access to experienced CTEPH centres are important priorities.

How to replace a bioprosthetic aortic valve within the Bentall graft.

The Bentall procedure using a bioprosthesis-containing conduit carries the risk of structural valve deterioration within the patients' lifetime. Failed aortic bioprosthesis replacement requires a redo aortic root replacement that is associated with significant morbidity and mortality. We describe an original "neo-annulus" technique of aortic valve replacement (AVR) within the Bentall graft. This technique involves an incision of the Bentall valve-containing aortic root conduit, cutting the stainless wireform stent and the inner plastic stent of the bioprosthetic valve at the tips of commissure posts with a wire cutter, removal of semilunar fragments of the remaining stainless wire, division of the fabric of the valve between the valve sewing cuff and the Elgiloy alloy base ring leaving the sewing cuff of the excised aortic valve bioprosthesis attached to the Bentall conduit as a "neo-annulus". Subsequently, this neo-annulus is stitched with interrupted 2/0 Ticrone sutures and another prosthetic aortic valve implanted inside of the old Bentall conduit. The graft incision is closed with a continuous 4/0 polypropylene suture.

Surgery for Type A Aortic Dissection: 14-Year Contemporary Cohort Study.

BACKGROUND: Type A aortic dissection is a fatal condition warranting emergency surgery to prevent complications and death. We reviewed the contemporary trends, characteristics, outcomes and predictors of this operation at our centre over a 14-year period. METHODS: Consecutive patients undergoing type A aortic dissection surgery at Auckland City Hospital during March 2003-March 2017 were studied, and relevant characteristics and outcomes collected prospectively for statistical analyses. RESULTS: There were 327 patients included, and the number of operations each year remained similar from 2003-2010, and steadily increased thereafter. Median age was 60.6 years, with 124 (37.9%) females, 136 (41.6%) Maori or Pacific ethnicity, 319 (97.6%) emergency surgeries, 62 (19.0%) in a critical preoperative state and 154 (47.1%) having a malperfusion syndrome. Operative mortality occurred in 65 (19.9%), although this has decreased from 23.3% before 2014 to 14.0% since. Composite morbidity occurred in 212 (65.0%), predominantly acute kidney injury 134 (41.0%), ventilation >24 hours (129 (39.6%), return to theatre 94 (28.8%) and stroke 63 (19.3%). Survival at 1, 5 and 10 years was 79.0%, 71.7% and 57.8% respectively. Critical preoperative state and malperfusion syndrome were independent predictors of operative and long-term mortality and composite morbidity. CONCLUSION: Surgery for acute type A aortic dissection has been increasing since 2011 and continues to have high rates of operative mortality and morbidities, although the former has decreased since 2014. Critical preoperative state and malperfusion were the key predictors of adverse outcomes. After surviving the perioperative period, prognosis was good with low rates of late mortality.

Challenging corrective redo surgery in a patient presenting with severe aortic redilatation following an aortic root reduction aortoplasty with concomitant external wrapping.

We report a case of severe long-term failure of an aortic root reduction aortoplasty with external wrapping. The patient presented 13 years after the initial surgery with a large redilatation of the aortic root and major atrophy of the native aortic root wall inside the external wrap. This subsequently necessitated challenging corrective redo surgery with a Bentall procedure. This case highlights the potential long-term risk of redilatation posed by using reduction aortoplasty with concomitant aortic external wrapping as a technique to treat largely aneurysmal aortic roots.

Long-Term Outcomes in Patients Undergoing Consecutive Bioprosthetic Aortic Valve Replacement.

BACKGROUND AND AIM OF THE STUDY: Worldwide, there is increased use of bioprosthetic valves in the aortic position. Part of this increase has been patient-driven for quality of life reasons. More recently, bioprosthetic valves have been chosen by progressively younger patients, with a strategy of performing a valve-in-valve TAVI if the prosthesis should wear out. Thus, a review was undertaken of the present authors' experience with patients whose first two aortic valve replacements (AVRs) were with bioprosthetic valves. METHODS: Patients receiving consecutive bioprosthetic AVRs at the Green Lane Cardiothoracic Surgical Unit were identified from a departmental database. Data were retrieved from prospective databases, electronic and archived clinical records. Outcomes of interest were overall survival and freedom from a third or more AVR. RESULTS: A total of 267 patients met the inclusion criteria, with a mean follow up of 22.3 years. Concurrent procedures (e.g., coronary artery bypass grafting) were performed in 65.2% of patients that underwent two bioprosthetic AVRs, and in 79.8% of patients undergoing three or more bioprosthetic AVRs. Median survival of the cohort was 31.7 years. Age at operation was the best predictor of needing a third or more AVR. Receiver operating characteristic curve analysis identified that age <45 years at the first operation and <56 years at the second operation were the optimal cut-off point for the likelihood of needing a third or more aortic valve intervention. CONCLUSIONS: Overall survival for consecutive bioprosthetic AVRs was remarkably good. Data relating to consecutive bioprosthetic AVRs is of particular interest in the context of TAVI and valve-in-valve TAVI, which will likely significantly increase the number of patients receiving consecutive bioprosthetic valves. However, it must be noted that the majority of patients in this cohort required concurrent cardiac surgical procedures. The study results provided encouraging data for consecutive bioprosthetic AVRs, as well as data that may be of interest in the setting of TAVI being performed in younger cohorts of patients.

Comparison of Risk Scores for Prediction of Complications following Aortic Valve Replacement.

BACKGROUND: Risk models play an important role in stratification of patients for cardiac surgery, but their prognostic utilities for post-operative complications are rarely studied. We compared the EuroSCORE, EuroSCORE II, Society of Thoracic Surgeon's (STS) Score and an Australasian model (Aus-AVR Score) for predicting morbidities after aortic valve replacement (AVR), and also evaluated seven STS complications models in this context. METHODS: We retrospectively calculated risk scores for 620 consecutive patients undergoing isolated AVR at Auckland City Hospital during 2005-2012, assessing their discrimination and calibration for post-operative complications. RESULTS: Amongst mortality scores, the EuroSCORE was the best at discriminating stroke (c-statistic 0.845); the EuroSCORE II at deep sternal wound infection (c=0.748); and the STS Score at composite morbidity or mortality (c=0.666), renal failure (c=0.634), ventilation>24 hours (c=0.732), return to theatre (c=0.577) and prolonged hospital stay >14 days post-operatively (c=0.707). The individual STS complications models had a marginally higher c-statistic (c=0.634-0.846) for all complications except mediastinitis, and had good calibration (Hosmer-Lemeshow test P-value 0.123-0.915) for all complications. CONCLUSION: The STS Score was best overall at discriminating post-operative complications and their composite for AVR. All STS complications models except for deep sternal wound infection had good discrimination and calibration for post-operative complications.

Does removing Mannitol and Voluven from the priming fluid of the cardiopulmonary bypass circuit have clinical effects?

The Auckland Hospital cardiothoracic unit recently removed Mannitol and Voluven from its Plasma-lyte-based cardiopulmonary bypass (CPB) priming fluid. Like with any change to practice, a comprehensive audit should be performed to identify positive or negative effects. The aim of this retrospective analysis was to investigate the effect of changing the CPB prime constituents on fluid balance and clinical outcome parameters. Clinical records were reviewed for 100 consecutive patients undergoing primary, isolated coronary artery bypass grafting (CABG), 50 patients before the prime change and 50 after. All data were collated into a central database for analysis. Mean arterial pressure while on bypass was higher in the new prime group (61.5 mmHg versus 57.5 mmHg, p = .002). There was no significant difference in hematocrit, hemoglobin, serum sodium, serum potassium, or creatinine postoperatively between groups. In regard to important outcomes such as postoperative weight and fluid balance, time on ventilation, length of stay in the intensive care unit (ICU) or hospital, and mortality, there were no significant differences. Interestingly, new prime group spent a smaller proportion of their time in the ICU on mechanical ventilation (23% versus 36%, p = .022). Mannitol and Voluven, like with all drugs, carry their own potential adverse effects. This study demonstrates that removing Mannitol and Voluven from priming fluid did not have any detrimental effect on electrolytes, fluid status, and other important outcomes in this consecutive series of patients having primary isolated CABG surgery. The risk-benefit balance combined with the obvious economic benefit clearly favors removing Mannitol and Voluven from priming fluids.

Long-term survival after isolated tricuspid valve replacement.

BACKGROUND: Isolated replacement of the tricuspid valve is rare, and the decision to operate is difficult. This study reviews the in-hospital mortality and long-term survival after tricuspid valve replacement in the absence of concomitant left sided valve surgery. It identifies predictors of poor outcome. METHODS: All patients who underwent tricuspid valve replacement between January 1995 and December 2011 were retrospectively reviewed. Patients having concomitant mitral or aortic valve surgery were excluded. Logistic regression was used to identify predictors of early and late death. RESULTS: Twenty-nine cases were identified. There were six in-hospital deaths (20.6%), and eight late deaths. Ascites was associated with in-hospital death (hazard ratio 16.96; p=0.0052). Higher dose of Frusemide was associated with late mortality (hazard ratio 1.157 per 20mg increase; p=0.0155). Frusemide dose and ascites were both significantly associated with death overall (p<0.01). Survival analysis estimated a 50% probability of surviving to 12.45 years. CONCLUSIONS: Isolated tricuspid valve replacement has a high peri-operative risk. Long-term survival in this study was consistent with other reports. Ascites and higher doses of Frusemide were associated with poor outcomes.

Aortic valve repair: 49 year follow-up.

This case report reveals an encouraging long-term follow-up of an aortic valve repair performed in 1962 by Sir Brian Barrett-Boyes. At last follow-up in 2011, 49 years after aortic valve repair, there was only trivial aortic regurgitation. This length of follow-up is considerably longer than that which currently exists in the literature for aortic valve repair.

Medium-term outcomes from mitral valve surgery for rheumatic heart disease in young adults in Aotearoa New Zealand: a cohort study.

BACKGROUND: Rheumatic heart disease (RHD) remains an important cause of morbidity and mortality in New Zealand. Factors associated with the choice of surgical treatment for advanced RHD in young adults are poorly understood. We sought to review our local experience with the surgical management of young adults with rheumatic mitral valvular disease. METHODS: From 2003 to 2016, all patients aged 15-24 years undergoing mitral valve surgery for rheumatic disease at Auckland City Hospital, New Zealand were retrospectively reviewed. RESULTS: During the 13-year study period, 73 young adults underwent mitral surgery; 85% were Maori or Pacific Islanders. Mitral repair was performed in 32 patients and replacement in 41 patients. Isolated mitral valve surgery was performed in 36%, double valve procedures in 47%, and triple valve procedures in 17% of patients. The 30-day mortality rate and stroke rate were 1.4% and 2.7% respectively. The medium-term mortality rate was 11.9% across a mean follow-up of 6 years (6.9% in the repair group, 15.8% in the replacement group, p = 0.25). There were increased bleeding complications (p = 0.04) in patients with mechanical mitral valve replacement. For patients on warfarin, across medium-term follow-up, the INR was in the therapeutic range only 23% of the time. CONCLUSION: Most young adults in New Zealand with severe RHD requiring surgery are of indigenous Maori or Pacific Island ethnicity. There is a trend towards improved survival with mitral repair. There is a significant tendency towards increased bleeding complications in patients on warfarin for mechanical mitral replacement. Warfarin compliance is poor.

Acute ischaemic ventricular septal defect--a formidable surgical challenge.

BACKGROUND: To evaluate our surgical results for Acute Ischaemic Ventricular Septal Defect and suggest practice guidelines. METHODS: Retrospective review of data from patient records between 1992 and 2006 for presentation, surgical approaches, morbidity and mortality, statistically analysed to derive guidelines for management. RESULTS: We had 36 patients with a mean age of 70.44(+/-6.34) years. Fourteen patients had inferior defects. Twenty-eight patients were in shock (22 on pre-operative IABP). Severe LV and RV dysfunction were present in 18 and 20 patients respectively. At surgery, 17 had infarct resection with patching while 18 had repair with infarct exclusion. Concomitant CABG was performed in 15. One patient was re-operated on for mitral valve replacement and one for recurrent VSD. Recurrent VSD was common (11 patients). Two of these patients underwent percutaneous device closure of whom one died. Prolonged ICU and hospital stay was normal. Early mortality was 52.78% (inferior defects-85.71% and anterior defects-31.82%). Inferior VSD (OR 7.7) and pre-operative shock (OR 6.7), predicted mortality. The subgroup of inferior VSD with shock had mortality equating that with medical management published in literature. CONCLUSIONS: Acute Ischaemic VSD is a grim surgical disease marked by residual shunts and high mortality. Patients with inferior defects with shock should be offered surgery only under exceptional circumstances.

Comparison of characteristics and outcomes for type A aortic dissection surgery by Maori, Pasifika or other ethnicities.

BACKGROUND: Aortic dissection is a life-threatening condition frequently requiring emergency surgery. Key risk factors include hypertension and aortopathy syndromes; however, possible ethnic associations and differences in presentation and outcomes are less well established. We compared characteristics and outcomes of type A aortic dissection surgery by ethnicity. METHODS: Consecutive patients having type A aortic dissection surgery at Auckland City Hospital March 2003-March 2017 were divided into three ethnic groups: Maori, Pasifika and 'other', and analysed for characteristics, presentation and outcomes. RESULTS: Among 327 patients, 45 (14%) were Maori, 91 (28%) were Pasifika Islander and 191 (58%) were other ethnicities. Mean age was lowest for Maori 51+/-12 years, then Pasifika 56+/-12 and other ethnicities 63+/-13 (P<0.001). Maori and Pasifika ethnicities had higher body mass index, more hypertension, dyslipidaemia and smoking, but lower proportion presenting in critical pre-operative state. Operative mortality occurred in 5 (11%), 18 (20%) and 42 (22%) for Maori, Pasifika and other ethnicities (P=0.258). Pasifika had higher age-standardised operative mortality standardised mortality ratio 6.00, 95% confidence interval 3.67-9.30 than 'other' ethnicities, while Maori had higher age-standardised late mortality 5.71, 2.90-10.2 respectively, and the latter association persisted in multivariable analysis. Critical pre-operative state and malperfusion syndrome independently predicted operative mortality. CONCLUSION: Maori and Pasifika patients were younger and present less unwell with type A aortic dissection, but had higher prevalence of cardiovascular risk factors. They had higher age-standardised late and operative mortality respectively, suggesting that aggressive management and risk factor control are critical for these patients.

Acute papillary muscle infarction and rupture in the puerperium complicating Libman-Sacks endocarditis in a patient with systemic lupus erythematosus and antiphospholipid syndrome: a case report.

BACKGROUND: Acute heart failure caused by severe mitral regurgitation (MR) due to papillary muscle rupture has been described in the puerperium by case reports; however, the majority of cases of papillary muscle rupture are caused by myocardial infarction. We describe papillary muscle rupture occurring in the postpartum period in a patient with systemic lupus erythematosus (SLE), antiphospholipid syndrome (APLS), and chronic Libman-Sacks endocarditis and explore the multifactorial nature of the papillary muscle infarction and rupture in the setting of postpartum fluid shifts, chronic myocardial injury from Libman-Sacks, and high thrombotic risk. CASE SUMMARY: A 29-year-old woman presented with acute heart failure 2 weeks' postpartum and was found to have acute MR due to a flail leaflet caused by papillary muscle rupture. She proceeded to emergency surgery with mitral valve (MV) replacement and the histology revealed evidence of chronic Libman-Sacks endocarditis and papillary muscle infarction with thrombi in the intramyocardial arteries. DISCUSSION: This is the second case report of papillary muscle rupture in the puerperium in a patient with SLE in the literature, the other case was caused by catastrophic APLS. However, in this case, the cause of the rupture is likely to be multifactorial; as a consequence of thrombosis in the microvasculature causing isolated papillary muscle ischaemia, and fibrosis of the muscle due to chronic Libman-Sacks endocarditis resulting in limited pliability which caused rupture of the papillary muscle when faced with the added stress of increased volume that occurs in the puerperium.

Large Left Ventricular Outflow Tract Pseudoaneurysm Closed Percutaneously From a Novel Apical Approach.

An incidental finding of a large left ventricular outflow tract pseudoaneurysm in a 74-year-old man, with high surgical risk, was managed with a novel, fully percutaneous, left ventricular apical approach. The pseudoaneurysm defect and the apical puncture site were successfully closed with Amplatzer septal occluders with successful positioning, as demonstrated on cardiac computed tomography at 6 weeks follow-up. (Level of Difficulty: Intermediate.).

Isolated mediastinal adenopathy: the case for mediastinoscopy.

BACKGROUND: We report our experience with mediastinoscopy at Auckland city hospital, a tertiary referral centre. We wished to examine correlations between clinical diagnosis and that made by histological sampling of enlarged mediastinal nodes particularly in patients with isolated mediastinal adenopathy. METHODS: We retrospectively reviewed clinical records of all patients who underwent mediastinoscopy in a five year period, mediastinoscopy was performed in the presence of enlarged lymph nodes (short axis > 1cm) found at CT. Mediastinoscopy was indicated for diagnostic staging of mediastinal adenopathy related to a parenchymal lung mass, diagnosis of isolated mediastinal adenopathy and diagnosis of mediastinal adenopathy with other CT findings. Data relating to indication, pre-test diagnosis, node stations sampled, histology, and operative complications were collected. RESULTS: Mediastinoscopy was performed in 137 consecutive patients. Seventy five patients had a lung mass, 47 had isolated mediastinal adenopathy and 15 had other CT findings. One operative complication occurred. In those patients with isolated adenopathy the following diagnoses were reached; sarcoidosis 23, TB 15, lymphoma 4, carcinoma 4, no diagnosis 1. Final diagnosis was significantly associated with patient's ethnicity. There was high sensitivity and specificity on comparison of clinical and histological diagnosis for both TB and sarcoidosis cases. CONCLUSIONS: Mediastinoscopy proved to be safe and effective in nodal assessment of the mediastinum. In carefully selected cases procedural morbidity and mortality may be avoided by application of features related to patient's ethnicity and radiological findings.

Prolonged Survival of Pulmonary Artery Sarcoma After Aggressive Surgical Resection.

Pulmonary artery sarcomas are rare tumors with a poor prognosis. Presentation is usually with symptoms of cardiorespiratory dysfunction, and although preoperative diagnosis was unusual historically, modern imaging techniques allow a high degree of confidence, and transvenous catheter biopsy can give confirmation of the diagnosis. This patient survived 6 years after surgical resection of the tumor and left lung with pulmonary artery reconstruction followed by postoperative adjuvant chemotherapy. The prolonged survival supports an aggressive approach in suitable cases.