Introduction of ex vivo perfusion of extended-criteria donor hearts in a single center in Asia.

The shortage of organs for heart transplantation has created a need to explore the use of extended-criteria organs. We report the preliminary use of normothermic TransMedics Organ Care System-an ex vivo approach to preserve extended-criteria brain-dead donor hearts. This System maintains a normal temperature, provides continuous perfusion and oxygenation, reduces ischemic time, and enables additional viability assessment options. In a retrospective single-centre study conducted from April 2020 to March 2023, four extended criteria brain-dead donor hearts were perfused and monitored using the Organ Care System. Suitability for transplantation was assessed based on stable or decreasing lactate levels, along with appropriate perfusion parameters. The Organ Care for use of the Organ Care System were coronary artery disease, left ventricular hypertrophy, high-dose inotrope use in the donor, a downtime exceeding 20 min, and a left ventricular ejection fraction of 40-50%. Three out of the four donor hearts were transplanted, while one was discarded due to rising lactate concentration. The three recipients had a higher surgical risk profile for heart transplant. All showed normal cardiac function and no primary graft dysfunction postoperatively. At 2-3 years post-transplant, all recipients have a ventricular function of > 60%, with only one showing evidence of mild rejection. The Organ Care System enables the successful transplantation of marginal donor organs in high-risk recipients, showcasing the feasibility of recruiting donors with extended criteria. This technique is safe and promising, expanding the donor pool and addressing the organ shortage in heart transplantation in Hong Kong.

Feasibility of concomitant exclusion of left atrial appendage during novel transapical off-pump beating heart mitral valve repair.

The AtriClip device enables the safe and reproducible epicardial clipping of the left atrial appendage. Transapical off-pump beating heart mitral valve repair using NeoChord DS100 Artificial Chordae Delivery System has matured and become more standardized. We aim to evaluate the feasibility of combining NeoChord repair and left atrial appendage exclusion in a single procedure through the same minithoracotomy in patients with mitral valve prolapse and atrial fibrillation. From 2018 to 2019, seven patients with severe mitral regurgitation and atrial fibrillation underwent transesophageal echocardiography-guided transapical off-pump mitral valve repair with the novel NeoChord DS 1000 system and concomitant left atrial appendage exclusion using the AtriClip Pro II device. Both procedures were performed via left mini-thoracotomy. The AtriClip device was applied after the NeoChord repair was done. All seven patients had less than moderate mitral regurgitation after the NeoChord repair and successful left atrial appendage occlusion. There were no device or procedure-related complications. Clinical follow-up revealed significant symptomatic improvement, and no cardiovascular complications were reported. Transesophageal echocardiography at 6-12 months post-procedure showed stable left atrial appendage occlusion with no residual flow between the left atrium and the left atrial appendage and a stump of less than 5 mm. Beating heart epicardial clipping of the left atrial appendage using AtriClip concomitant with transapical mitral valve repair using Neochord DS 1000 system is a feasible and safe treatment option in mitral valve prolapse and atrial fibrillation in patients with limited indications. However, its safety needs to be confirmed in a larger series of patients.

CT texture analysis in predicting treatment response and survival in patients with hepatocellular carcinoma treated with transarterial chemoembolization using random forest models.

BACKGROUND: Using texture features derived from contrast-enhanced computed tomography (CT) combined with general imaging features as well as clinical information to predict treatment response and survival in patients with hepatocellular carcinoma (HCC) who received transarterial chemoembolization (TACE) treatment. METHODS: From January 2014 to November 2022, 289 patients with HCC who underwent TACE were retrospectively reviewed. Their clinical information was documented. Their treatment-naïve contrast-enhanced CTs were retrieved and reviewed by two independent radiologists. Four general imaging features were evaluated. Texture features were extracted based on the regions of interest (ROIs) drawn on the slice with the largest axial diameter of all lesions using Pyradiomics v3.0.1. After excluding features with low reproducibility and low predictive value, the remaining features were selected for further analyses. The data were randomly divided in a ratio of 8:2 for model training and testing. Random forest classifiers were built to predict patient response to TACE treatment. Random survival forest models were constructed to predict overall survival (OS) and progress-free survival (PFS). RESULTS: We retrospectively evaluated 289 patients (55.4 ± 12.4 years old) with HCC treated with TACE. Twenty features, including 2 clinical features (ALT and AFP levels), 1 general imaging feature (presence or absence of portal vein thrombus) and 17 texture features, were included in model construction. The random forest classifier achieved an area under the curve (AUC) of 0.947 with an accuracy of 89.5% for predicting treatment response. The random survival forest showed good predictive performance with out-of-bag error rate of 0.347 (0.374) and a continuous ranked probability score (CRPS) of 0.170 (0.067) for the prediction of OS (PFS). CONCLUSIONS: Random forest algorithm based on texture features combined with general imaging features and clinical information is a robust method for predicting prognosis in patients with HCC treated with TACE, which may help avoid additional examinations and assist in treatment planning.

Proximalization of Frozen Elephant Trunk Procedure: Zone 0 or 1 versus Zone 2 or 3 Arch Repair.

BACKGROUND: Total arch replacement with the frozen elephant trunk (FET) procedure has changed the landscape of therapy for aortic arch diseases. The optimal landing zone for a FET is controversial. We sought to share our early and midterm results of the FET procedure as well as compare the clinical outcomes of proximal and distal FET anastomosis. METHODS: A total of 100 patients who underwent total arch replacement using the FET technique were identified between November 2014 and August 2021. According to the FET anastomosis over the aortic arch, patients were classified into two groups (zone 0/1 vs. zone 2/3). In-hospital mortality, complications, and midterm outcomes were assessed based on patient characteristics. RESULTS: The overall in-hospital mortality was 8%. Major complications occurred in 32% of patients, including spinal cord injury (5%), stroke (7%), and acute kidney injury requiring dialysis (7%). Zone 2/3 FET (odds ratio: 6.491, 95% confidence interval: 1.930-21.835, p = 0.003) was an independent predictor of the composite endpoint of major complications. The rate of complete false lumen thrombosis was comparable (64.3% vs. 71.4%, p = 0.567). All patients, patients with zone 0/1 FET, and patients with zone 2/3 FET had 3-year freedom from aorta-related events of 73.0, 70.2, and 75.0%, respectively. There were no significant differences (log-rank test, p = 0.500). CONCLUSION: Compared with zone 2/3, proximalization of FET using zone 0/1 for anastomosis was associated with better early outcomes and comparable rates of midterm aorta-related events. To substantiate its use, more research on this approach is required.

Hybrid approach for cerebral protection in open-heart surgery: Case series.

BACKGROUND: Stroke remains one of the most important complications of cardiac surgery and occurs in 2.2% after open-heart procedure. It is associated with significant morbidity and mortality. The use of a cerebral protection system during transcatheter aortic valve implantation may be associated with a lower risk of periprocedural strokes, and mortality at 30 days. The aim of the present study was to assess the safety and feasibility of this device in patients at high risk for stroke during open cardiac surgery. METHODS: We present six patients with a high risk of perioperative stroke who underwent placement of Sentinel cerebral protection system during various open-heart operations between 2018 and 2021. RESULTS: The system was successfully deployed, and debris was retrieved in all patients. There was no device-related complication or development of ischemic stroke postoperatively. One patient suffered from intracranial hemorrhage due to peri-operative coagulopathy. CONCLUSIONS: We demonstrated the feasibility and safety of this hybrid approach with a high debris capture rate. It encourages further study to evaluate the benefits of the Sentinel cerebral protection system in reducing stroke and mortality in selected patients undergoing open-heart surgery.

Transapical transcatheter J-valve for aortic regurgitation in dextrocardia situs inversus.

A 71-year-old lady with dextrocardia and pure aortic regurgitation was treated with transcatheter aortic valve replacement using the transapical J-valve system. Good clinical and echocardiographic results were demonstrated at one-year follow-up. Herewith we describe this simple, safe, and a minimally invasive aortic valve replacement option for this condition.

Emerging roles of left ventricular assist device therapy as bridge to transplant in an Asian city with scarce heart transplant donor.

BACKGROUND: Left ventricular assist device (LVAD) has been increasingly used in patients with advanced heart failure. This study aimed to assess the impact of implementation of LVAD therapy on heart transplantation (HTx) service in Hong Kong (HK). METHODS: LVAD program was started in 2010 in HK and patients who had been put on HTx waiting list since the start of HTx program in HK from 1992 to 2020 were included for analysis. Survival on HTx waiting list between pre-LVAD era 1992-2009 and post-LVAD era 2010-2020 were analyzed by Kaplan-Meier method and compared by log-rank test. Multivariate analysis by time-dependent Cox-proportional hazard model was used to identify independent predictors of HTx waiting list mortality. RESULTS: A total of 478 heart transplant listing episodes involving 457 patients were included for analysis. There were 232 heart transplantations (HTxs), including one re-transplantation, during the study period. There were 110 patients who received LVAD as bridge to transplantation (BTT) and 30 of them had undergone subsequent HTx. The 1-, 2- and 3-year survival on waiting list were 82.3%, 61.7% and 43.0% respectively in the pre-LVAD era (n=178), while the 1-, 2- and 3-year survival were significantly improved at 85.7%, 81.8% and 78% respectively in the post-LVAD era (n=300), (P=0.003). Time-dependent multivariate analysis revealed that LVAD support was independently associated with significant reduction of waiting list mortality [odds ratio (OR): 0.21; 95% confidence interval (CI): 0.10-0.44, P<0.001]. There was no significant difference when comparing survival after LVAD as BTT and survival after HTx up to 8 years (76.1% vs. 72% at 8 years respectively, P=0.732). CONCLUSIONS: Waiting list survival improved in the post-LVAD era driven by the implementation of LVAD service. Long-term survival for LVAD recipients as BTT were comparable to heart transplant recipients in HK.

Long term CentriMag biventricular support using hybrid cannulation as a bridge to transplant in a pediatric patient.

Paracorporeal continuous-flow ventricular assist devices designed for short-term support can also potentially provide long-term circulatory support as bridges to transplantation in children. We describe the long-term use of the CentriMag biventricular assist device with multiple pump changes in a 9-year-old boy with idiopathic-dilated cardiomyopathy. The initially implanted Berlin Heart EXCOR pumps were replaced by CentriMag due to thromboembolic complications. The CentriMag pumps were exchanged 15 times due to clot and fibrin formation or when the pumps reached their expiration dates. Connecting CentriMag to Berlin Heart EXCOR cannulae effectively served as an alternative long-term hybrid bridge to transplantation for 235 days. The patient successfully underwent a transplant after 284 days. Judicious pump monitoring and timely pump exchanges can potentially overcome device-related complications and extend the duration on support.

Feasibility of novel transapical off pump beating heart mitral valve repair in a patient with dextrocardia and situs inversus.

We present a case to demonstrate the feasibility of transapical beating heart mitral valve repair in a patient with dextrocardia. This minimally invasive technique provides simple, safe and satisfactory mitral repair. The surgical technique, outcome and prognosis are not affected by the condition.

The Association Between Child Abuse and Attempted Suicide.

Background: Child abuse and suicide among the young population is a serious and prevalent problem. Many studies have demonstrated that people with adverse childhood experiences, such as child abuse, are likely to develop suicidal behavior. This study evaluates the connection between child abuse and suicidal behavior in the Hong Kong community where incidents of child abuse have been on the rise over the past decade. Aims: To determine the association between child abuse and attempted suicide in the child population of Hong Kong using hospital electronic medical records system. Method: From January 1, 1995 to July 31, 2016, patients with admission age < 18 years with the diagnosis of child abuse or influenza infection (comparison group) were included in this study (n = 54,256). In secondary data analysis, an association was found between children who had experienced child abuse and the outcome measure of hospital admission for attempted suicide compared with influenza infection. Results: The adjusted hazard ratio of attempting suicide in children who experienced sexual abuse and physical abuse compared with the influenza-infected group was 6.48 (95% CI [4.56, 9.19]) and 4.83 (95% CI [3.67, 6.34]). The age at onset of adverse incidents was negatively associated with the attempted suicide timing. Female patients had a 1.64 higher risk of repeating attempted suicide. In addition, nearly 5% of children who had experienced child abuse attempted suicide in the 10 years after their admission, and more than 36% of patients had a record of repeated suicide attempt in the 20 years after the initial admission. Limitations: The accuracy of the diagnosis, selection bias, insufficiency of study period, Berkson's bias, incomplete socioeconomic status, as well as the absence of psychiatric diagnosis are the limitations. Conclusion: Our results indicate that there is a significant association between child abuse and suicide attempts in Hong Kong. If confirmed, the study (a) demonstrates that hospital admission records are a critical source for identifying children with a high risk for suicidal behavior; (b) may inform policy makers that additional and long-term intervention programs should be provided to children so as to reduce subsequent suicide attempts.

Pediatric ventricular assist device therapy for advanced heart failure-Hong Kong experience.

Ventricular assist devices (VADs) are life-saving options for children with heart failure unresponsive to medical therapy as a bridge to transplantation or cardiac recovery. We present a retrospective review of 13 consecutive children who underwent implantation of VAD between 2001 and 2018 in our center. The median age was 12 years (1-17 years), weight was 45 kg (10-82 kg). Etiologies of heart failure were dilated cardiomyopathy (CMP) (n = 8), myocarditis (n = 2), ischemic CMP (n = 1), restrictive CMP (n = 1) and congenital heart disease (n = 1). Pre-implantation ECMO was used in 5, mechanical ventilation in 4, renal replacement therapy in 2 and IABP in 1. Devices used were: Berlin Heart EXCOR left VAD (LVAD), biventricular VAD (BIVAD) (n = 5, 2), CentriMag LVAD, BIVAD (n = 1, 2), HeartWare (n = 2), HeartMate II (n = 1). Median duration of support was 45 days (3-823 days). Overall survival was 85%. Four patients were successfully bridged to transplantation, 2 died while on a device, 4 remain on support and 3 were weaned from VAD. Late death occurred in 2 transplanted patients. Complications included bleeding requiring reoperation in 1, neurologic events in 3, driveline infections and pericardial effusion in 2 each. In one patient, CentriMag BIVAD provided support for 235 days, which is longest reported duration on such a VAD in the Asia Pacific region. Survival for pediatric patients of all ages is excellent using VADs. Given the severity of illness in these children morbidity and mortality is acceptable. VADs could potentially be used as a long-term bridge to transplantation in view of the donor shortage in the pediatric population.

Porcine Versus Pericardial Pulmonary Valve Replacement in Adults With Prior Congenital Cardiac Surgery: Midterm Outcomes.

BACKGROUND: Postcongenital heart surgery pulmonary regurgitation requires subsequent pulmonary valve replacement. We sought to compare the outcomes of pulmonary valve replacement after using bioprosthetic valves, porcine versus pericardial bioprosthesis. METHOD: Retrospective single-center study of consecutive pulmonary valve replacement in patients with pulmonary regurgitation following initial congenital cardiac surgery. From 2004 to 2016, 82 adult patients (53 males, 29 females) underwent pulmonary valve replacement at a mean age of 28.7 ± 8 years (range 18-52 years) with a mean time to pulmonary valve replacement of 24 ± 7 years (range 13-43 years). Porcine bioprosthetic valves (group 1, n = 32) and pericardial valves (group 2, n = 50) were used. Cardiac magnetic resonance imaging was performed (n = 54) at a mean of 18 ± 13 months before and 24 ± 21 months after pulmonary valve replacement. RESULTS: No significant difference was seen between the groups except that the mean follow-up was longer for group 1 (5.02 ± 2.06 vs 4.08 ± 3.21 years). In-hospital mortality was 1.1%. Follow-up completeness was 100% with no late death. Mean right ventricular end-systolic and end-diastolic volumes reduced significantly in both the groups ( P < .001), whereas right ventricular ejection fraction remained unchanged (group 1, P = .129; group 2, P = .675) . Only the left ventricular end-diastolic volume increased in both the groups, but the increase was significant for group 2 only (group 1, P = .070; group 2, P = .015), whereas the left ventricular end-systolic and ejection fraction remained unchanged in both the groups. There was no reoperation for pulmonary valve replacement. Freedom from intervention was 93.8% (group 1) and 100% (group 2) at eight years after pulmonary valve replacement ( P = .407). CONCLUSION: Midterm outcomes of pulmonary valve replacement in our adult cohort were satisfactory. Both types of bioprosthetic valves performed comparably for eight years and were a good option in adults.

The history of lung transplantation in Hong Kong.

Clinical lung transplant was first performed in Hong Kong in 1995. In the early years, the volume of activity was very low. There has been a clear trend of increasing volume in the past few years. The recipient pathology is very different from the International Society for Heart and Lung Transplantation (ISHLT) database, with complete absence of cystic fibrosis and alpha-1-antitrypsin deficiency, and a predominance of diseases of the pulmonary circulation. Lymphangioleiomyomatosis (LAM) has a much higher representation on the waiting list than the ISHLT. The survival of patients who received a lung transplant in Hong Kong compares favorably with international data.

Proteomic analysis of neonatal mouse brain: evidence for hypoxia- and ischemia-induced dephosphorylation of collapsin response mediator proteins.

Perinatal hypoxia and ischemia (HI) are a significant cause of mortality and morbidity. To understand the molecular mechanisms for HI-induced brain damage, here we used a proteomic approach to analyze the alteration and modification of proteins in neonatal mouse brain 24 h after HI treatment. Significant changes of collapsin response mediator proteins (CRMPs) were observed in HI brain. CRMPs are a family of cytosolic proteins involved in axonal guidance and neuronal outgrowth. We found that CRMP2, CRMP4 and CRMP5 proteins were altered post-translationally after HI treatment. Mass spectrometric and Western blot analyses detected hypophosphorylated CRMP proteins after HI. Further analysis of CRMP kinases indicated inactivation of cyclin dependent kinase 5 (CDK5), a priming kinase of CRMPs and a neuronal specific kinase that plays pivotal roles in neuronal development and survival. The reduction of CDK5 activity was associated with underexpression of its activator p35. Taken together, our findings reveal HI-induced dephosphorylation of CRMPs in neonatal brain and suggest a novel mechanism for this modification. Hypophosphorylated CRMPs might be implicated in the pathogenesis of HI-related neurological disorders.

Comparing diffusion-weighted and T2-weighted MR imaging for the quantification of infarct size in a neonatal rat hypoxic-ischemic model at 24h post-injury.

PURPOSE: In a neonatal rat model of hypoxic-ischemic (HI) brain injury, using T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI), we aim to determine the best MRI method of lesion quantification that reflects infarct size. MATERIALS AND METHODS: Twenty 7-day-old rats underwent MRI 24h after HI brain injury was induced. Lesion size relative to whole brain was measured using T2WI and apparent diffusion coefficient (ADC) maps, applying thresholds of 60%, 70% and 80% contralateral control hemisphere mean ADC, and at day 10 post-HI on pathology with TTC staining. Multiple linear regression analysis was used to study the relationships between lesion size at MRI and pathology. RESULTS: Lesion size measurement using all MRI methods significantly correlated with infarct size at pathology; using T2WI, r=0.808 (p<0.001), using 80% ADC, 70% ADC and 60% ADC thresholds, r=0.888 (p<0.001), 0.761, (p<0.001) and 0.569 (p=0.014), respectively. Eighty percent ADC threshold was found to be the only significant independent predictor of final infarct volume (adjusted R(2)=0.775). CONCLUSION: At 24h post-HI, lesion size on DWI, using 80% ADC threshold is the best predictor of final infarct volume. Although T2WI performed less well, it has the advantage of superior spatial resolution and is technically less demanding. These are important considerations for experiments which utilize MRI as a surrogate method for lesion quantification in the neonatal rat HI model.