The Optimisation of Arteriovenous Fistula Vascular Access Outcomes for Haemodialysis

End Stage Renal Failure, requiring renal replacement therapy, is delivered most commonly via haemodialysis (HD). The gold standard Vascular Access (VA) for HD is the arteriovenous fistula (AVF). However, it can be difficult to establish and maintain a mature AVF. A comprehensive vascular access service model was established with the aim of streamlining AVF care, allowing for the introduction of innovative solutions (over the subsequent years) to AVF pathologies and close observation of AVF experimental outcomes. This service resulted in an improvement in multiple VA outcomes and a reduction in VA expenditure. Innovative solutions focused on improving the reliability of the AVF through addressing known inflow, cannulation zone and outflow AVF pathologies were developed. We implanted an interwoven nitinol stent to approximate the optimal fluid dynamic geometry to treat stenoses of the inflow juxta-anastomosis (JXAS). We found acceptable patency results with no loss of AVFs in the long term results. A dynamic banding (DYBAND) technique was developed to treat excessive AVF inflow, allowing for band adjustment in concert with flow rate measurement, thus achieving the optimal band diameter for every individual AVF. The dysfunctional cannulation zone was addressed with cannulation zone stenting, allowing immediate puncture for dialysis. In a multi-centre study, we found acceptable outcomes and patency of AVFs to 4 years follow up, with a low rate of re-intervention. A pilot study with drug eluting stents in the AVF cannulation zone was performed to improve patency results. Whilst we were able to determine acceptable patency results, cessation of dual antiplatelet therapy in the medium-term post implantation was associated with stent thrombosis, hence limiting widespread adoption. During the study, a meta-analysis (Katsanos et al), determined a significant mortality risk associated with a commonly applied AVF first line therapy, drug eluting balloons (DEB). We performed a meta-analysis and demonstrated no such effect was present in AVF patients receiving a DEB. With increasing confidence from the aforementioned therapies, we combined these treatments as an adjuvant to AVF formation. The study demonstrated that timely, near universal AVF maturation was achieved, with all AVFs maintained utilising a low rate of re-intervention. The methods and results presented in this thesis demonstrates that for incident dialysis dependency, under the supervision of an RVAC, patients can have an AVF formed, matured and maintained for long term access

PRELIMINARY FINDINGS OF A POTENZIATED PIEZOSURGERGICAL DEVICE AT THE RABBIT SKULL

The number of available ultrasonic osteotomes has remarkably increased. In vitro and in vivo studies have revealed differences between conventional osteotomes, such as rotating or sawing devices, and ultrasound-supported osteotomes (Piezosurgery®) regarding the micromorphology and roughness values of osteotomized bone surfaces. Objective: the present study compares the micro-morphologies and roughness values of osteotomized bone surfaces after the application of rotating and sawing devices, Piezosurgery Medical® and Piezosurgery Medical New Generation Powerful Handpiece. Methods: Fresh, standard-sized bony samples were taken from a rabbit skull using the following osteotomes: rotating and sawing devices, Piezosurgery Medical® and a Piezosurgery Medical New Generation Powerful Handpiece. The required duration of time for each osteotomy was recorded. Micromorphologies and roughness values to characterize the bone surfaces following the different osteotomy methods were described. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and atomic force microscopy. The selective cutting of mineralized tissues while preserving adjacent soft tissue (dura mater and nervous tissue) was studied. Bone necrosis of the osteotomy sites and the vitality of the osteocytes near the sectional plane were investigated, as well as the proportion of apoptosis or cell degeneration. Results and Conclusions: The potential positive effects on bone healing and reossification associated with different devices were evaluated and the comparative analysis among the different devices used was performed, in order to determine the best osteotomes to be employed during cranio-facial surgery

Diseases of the Brain, Head and Neck, Spine 2020–2023

This open access book offers an essential overview of brain, head and neck, and spine imaging. Over the last few years, there have been considerable advances in this area, driven by both clinical and technological developments. Written by leading international experts and teachers, the chapters are disease-oriented and cover all relevant imaging modalities, with a focus on magnetic resonance imaging and computed tomography. The book also includes a synopsis of pediatric imaging. IDKD books are rewritten (not merely updated) every four years, which means they offer a comprehensive review of the state-of-the-art in imaging. The book is clearly structured and features learning objectives, abstracts, subheadings, tables and take-home points, supported by design elements to help readers navigate the text. It will particularly appeal to general radiologists, radiology residents, and interventional radiologists who want to update their diagnostic expertise, as well as clinicians from other specialties who are interested in imaging for their patient care

Smoking and Second Hand Smoking in Adolescents with Chronic Kidney Disease: A Report from the Chronic Kidney Disease in Children (CKiD) Cohort Study

The goal of this study was to determine the prevalence of smoking and second hand smoking [SHS] in adolescents with CKD and their relationship to baseline parameters at enrollment in the CKiD, observational cohort study of 600 children (aged 1-16 yrs) with Schwartz estimated GFR of 30-90 ml/min/1.73m2. 239 adolescents had self-report survey data on smoking and SHS exposure: 21 [9%] subjects had “ever” smoked a cigarette. Among them, 4 were current and 17 were former smokers. Hypertension was more prevalent in those that had “ever” smoked a cigarette (42%) compared to non-smokers (9%),

The Prevalence of Termination Variations of the Basilar Artery:A Systematic Review and Meta-Analysis

Purpose: Understanding the vascular anatomical variations of the termination pattern of the basilar artery is crucial for both neurosurgical and interventional radiological procedures. Recent evidence indicates that variant bifurcation patterns of the basilar artery, differing from the classical textbook descrip- tion, are increasingly encountered. This study aims to provide a comprehensive summary of the prevalence of termination anomalies related to the basilar artery.Methods: This systematic review included human cadaveric and imaging studies on basilar artery termination patterns. PubMed, Ovid MEDLINE, and Scopus databases were system- atically searched in accordance with PRISMA guidelines, us- ing the terms “(basilar OR vertebrobasilar OR (posterior AND circulation)) AND (anatomy OR termination OR trifurcation OR quadfurcation OR pentafurcation OR hexafurcation OR nonfurcation OR variation OR variant)”. A meta-analysis of proportions was conducted to assess the prevalence of each variation using a random intercept logistic regression model, following logit transformation of the proportions.Results: From 845 initial hits, 4 articles were eligible for the quantitative analysis. The estimated pooled proportions of bifurcation, trifurcation, quadfurcation, pentafurcation, hexa- furcation, and non-furcation in the artery, under the random effects model, were 62.22% (95%CI [34.48%; 83.75%]), 6.08% (95%CI [2.60%; 13.58%]), 5.27% (95%CI [2.17%; 12.27%]),2.06% (95%CI [0.96%; 4.35%]), 0.49% (95%CI [0.08%; 2.90%]), and 0.10% (95%CI [0.0%; 17.07%]), respectively. Heterogeneity analysis revealed significant variability among the studies (I2 up to 93.6%, p&lt;0.0001).Conclusion: More than one-third of basilar artery termi- nations exhibit anatomical variations other than bifurcation. Trifurcation and quadfurcation are the most commonly re- ported variations, each accounting for over 5% of cases. These variations might carry significant implications for regional neurosurgical and interventional radiological procedures.<br/

A Rare Presentation of Infantile Mediastinal Mature Cystic Teratoma Leading to Progressive Respiratory Failure - A Case Series

Purpose: Teratoma is a congenital tumour arising from one or more of the three germ cell layers in the embryo, with an incidence of 1.2-14.2 cases per 100,000 people per year. Mature cystic teratomas contain bone, cartilage, hair, nails, and cystic fluid filled spaces. Extragonadal teratomas are uncommon, and are usually detected incidentally in adults. Here, we report three cases of infantile mediastinal mature cystic teratomas presenting with impending acute respiratory failure.Methods: Three previously healthy infants (two were boys) aged 5-6 months presented with worsening respiratory tract infection and impending respiratory failure despite medical management. A chest radiograph revealed a large anterior mediastinal mass. CECT chest demonstrated the mediasti- nal tumour suggestive of Teratoma with a mediastinal shift, cardiac and tracheal compression. None of them had features of local infiltration. It was decided to proceed with surgical excision after multidisciplinary discussions. Mediastinum was approached with muscle sparing posterolateral thoracotomy in two patients. And the other child underwent right anterolat- eral thoracotomy. Excision of the tumour relieved the airway obstruction and mediastinal shift.Results: The symptoms improved rapidly following the tumour excision, and they were gradually weaned off from respiratory support. They received ITU care and recovered un- eventfully with no surgical complications. The histology of the excised tumours confirmed mature cystic teratoma.Conclusion: Mature cystic teratoma may rarely present in infancy with progressive respiratory failure, hence clinicians should have a high degree of suspicion. Complete excision is possible in most cases where there is a clear plane of dissection with the lesion and the surrounding structures with excellent clinical outcomes. Both anterolateral and posterolateral thora- cotomy approaches could be used to access the mediastinum.<br/