Effectiveness of a native vein arteriovenous fistula tracking system.

OBJECTIVE: This study aims to evaluate the effectiveness of a tracking program on the functional maturation rate of arteriovenous fistula (AVF). METHODS: Two major clinical outcomes (commencement of cannulation and functional maturation) of created AVFs were compared between two cohorts. (i) Cohort 1: historical cohort; (ii) Cohort 2: AVFs created after implementation of the tracking project. Multivariable Cox regression models were used to assess the association between cohort allocation and the two major clinical outcomes. RESULTS: Data of 114 and 141 patients were analyzed respectively from Cohorts 1 (historical data) and 2 (with AVF tracking). After adjustment of covariates in the multivariable analysis, the AVFs created in Cohort 2 were more likely to be cannulated earlier (adjusted HR: 2.82; 95% CI: 1.97-4.05; p < 0.001), compared to those in Cohort 1. Similarly, the AVFs of Cohort 2 patients had significantly higher probability of functional maturation (adjusted HR: 1.81; 95% CI: 1.31-2.48; p < 0.001) than fistulas in Cohort 1. Cannulation was commenced for half of the AVFs by 4.1 months post-creation in the historical cohort (Cohort 1), whereas in the post-tracking cohort, 50% of the AVFs were cannulated by 2.3 months after creation (p < 0.001). It took 5.5 and 4.3 months for 50% of the AVFs created in Cohort 1 and Cohort 2 patients to achieve catheter-free functional maturation, respectively (p = 0.06). CONCLUSION: An AVF tracking program with maturation target for the access surgeons, together with a standardized tracking, feedback, and clinical strategy adjustment system is able to improve the AVF functional maturation rate.

Refining mass casualty plans with simulation-based iterative learning.

BACKGROUND: Preparatory, written plans for mass casualty incidents are designed to help hospitals deliver an effective response. However, addressing the frequently observed mismatch between planning and delivery of effective responses to mass casualty incidents is a key challenge. We aimed to use simulation-based iterative learning to bridge this gap. METHODS: We used Normalisation Process Theory as the framework for iterative learning from mass casualty incident simulations. Five small-scale 'focused response' simulations generated learning points that were fed into two large-scale whole-hospital response simulations. Debrief notes were used to improve the written plans iteratively. Anonymised individual online staff surveys tracked learning. The primary outcome was system safety and latent errors identified from group debriefs. The secondary outcomes were the proportion of completed surveys, confirmation of reporting location, and respective roles for mass casualty incidents. RESULTS: Seven simulation exercises involving more than 700 staff and multidisciplinary responses were completed with debriefs. Usual emergency care was not affected by simulations. Each simulation identified latent errors and system safety issues, including overly complex processes, utilisation of space, and the need for clarifying roles. After the second whole hospital simulation, participants were more likely to return completed surveys (odds ratio=2.7; 95% confidence interval [CI], 1.7-4.3). Repeated exercises resulted in respondents being more likely to know where to report (odds ratio=4.3; 95% CI, 2.5-7.3) and their respective roles (odds ratio=3.7; 95% CI, 2.2-6.1) after a simulated mass casualty incident was declared. CONCLUSION: Simulation exercises are a useful tool to improve mass casualty incident plans iteratively and continuously through hospital-wide engagement of staff.

Aortic root abscess and anomalous aortic origin of right coronary artery in a 5-year-old child.

BACKGROUND: Aortic root abscess is a rare complication of infective endocarditis in children. CASE REPORT: A 5-year-old boy with infective endocarditis of aortic valve and an anterior aortic root abscess was found to have anomalous aortic origin of right coronary artery from the left coronary sinus on computed tomography scan with contrast. RESULT: He was managed surgically by "patch and prosthesis" approach and required aortic root enlargement. Since anomalous aortic origin of right coronary artery is a relative contraindication for a Konno-Rastan aortic root enlargement, a Manouguian procedure was performed. CONCLUSION: Anterior aortic root abscesses are rare, the co-existence of anomalous aortic origin of right coronary artery is rarer still and such cases requiring aortic root enlargement are possibly best served by a Manouguian procedure.

Experience from a Singapore tertiary hospital with restructuring of a vascular surgery practice in response to national and institutional policies during the COVID-19 pandemic.

Singapore was one of the first countries to be affected by COVID-19, with the index patient diagnosed on January 23, 2020. For 2 weeks in February, we had the highest number of COVID-19 cases behind China. In this article, we summarize the key national and institutional policies that were implemented in response to COVID-19. We also describe in detail, with relevant data, how our vascular surgery practice has changed because of these policies and COVID-19. We show that with a segregated team model, the vascular surgery unit can still function while reducing risk of cross-contamination. We explain the various strategies adopted to reduce outpatient and inpatient volume. We provide a detailed breakdown of the type of vascular surgical cases that were performed during the COVID-19 pandemic and compare it with preceding months. We discuss our operating room and personal protective equipment protocols in managing a COVID-19 patient and share how we continue surgical training amid the pandemic. We also discuss the challenges we might face in the future as COVID-19 regresses.

ELSA recommendations for minimally invasive surgery during a community spread pandemic: a centered approach in Asia from widespread to recovery phases.

BACKGROUND: The COVID-19 pandemic has resulted in significant changes to surgical practice across the worlds. Some countries are seeing a tailing down of cases, while others are still having persistent and sustained community spread. These evolving disease patterns call for a customized and dynamic approach to the selection, screening, planning, and for the conduct of surgery for these patients. METHODS: The current literature and various international society guidelines were reviewed and a set of recommendations were drafted. These were circulated to the Governors of the Endoscopic and Laparoscopic Surgeons of Asia (ELSA) for expert comments and discussion. The results of these were compiled and are presented in this paper. RESULTS: The recommendations include guidance for selection and screening of patients in times of active community spread, limited community spread, during times of sporadic cases or recovery and the transition between phases. Personal protective equipment requirements are also reviewed for each phase as minimum requirements. Capability management for the re-opening of services is also discussed. The choice between open and laparoscopic surgery is patient based, and the relative advantages of laparoscopic surgery with regard to complications, and respiratory recovery after major surgery has to be weighed against the lack of safety data for laparoscopic surgery in COVID-19 positive patients. We provide recommendations on the operating room set up and conduct of general surgery. If laparoscopic surgery is to be performed, we describe circuit modifications to assist in reducing plume generation and aerosolization. CONCLUSION: The COVID-19 pandemic requires every surgical unit to have clear guidelines to ensure both patient and staff safety. These guidelines may assist in providing guidance to units developing their own protocols. A judicious approach must be adopted as surgical units look to re-open services as the pandemic evolves.

Self-assembly and conformational heterogeneity of the AXH domain of ataxin-1: an unusual example of a chameleon fold.

Ataxin-1 is a human protein responsible for spinocerebellar ataxia type 1, a hereditary disease associated with protein aggregation and misfolding. Essential for ataxin-1 aggregation is the anomalous expansion of a polyglutamine tract near the protein N-terminus, but the sequence-wise distant AXH domain modulates and contributes to the process. The AXH domain is also involved in the nonpathologic functions of the protein, including a variety of intermolecular interactions with other cellular partners. The domain forms a globular dimer in solution and displays a dimer of dimers arrangement in the crystal asymmetric unit. Here, we have characterized the domain further by studying its behavior in the crystal and in solution. We solved two new structures of the domain crystallized under different conditions that confirm an inherent plasticity of the AXH fold. In solution, the domain is present as a complex equilibrium mixture of monomeric, dimeric, and higher molecular weight species. This behavior, together with the tendency of the AXH fold to be trapped in local conformations, and the multiplicity of protomer interfaces, makes the AXH domain an unusual example of a chameleon protein whose properties bear potential relevance for the aggregation properties of ataxin-1 and thus for disease.

Unexplained systemic hypertension after closure of ductus arteriosus.

Immediately after surgical closure of a patent ductus arteriosus, a 12-year-old boy developed severe systemic arterial hypertension refractory to medication. The cause of hypertension could not be found, but it came under control 3 weeks postoperatively with a combination of angiotensin-converting enzyme inhibitor and chlorothiazide.

Wandering permanent pacemaker generators in children: a case series.

INTRODUCTION: Epicardial permanent pacemaker generators are implanted some times in the abdominal wall in pediatric age groups. CASE PRESENTATION: Three permanent epicardial pacemakers that migrated in an unusual manner producing intraabdominal complications are reported. CONCLUSION: The different clinical presentations of pacemaker migration in the pediatric age groups are highlighted and a few suggestions are made for avoiding such a complication.

Methemoglobinemia masquerading as pulmonary hypertension.

Pulmonary arterial hypertension is known to occur postoperatively after closure of VSD. It results in a low cardiac output state with need for ventilation and frequent bagging. Methemoglobinemia, a condition associated with toxic ingestions, has been described in this setting. Methemoglobinemia is known to cause cyanosis and hypotension. We report a critically ill infant with significant methemoglobinemia after VSD closure.