Eoghan Cunnane

• Doctor of Philosophy
• Fellow at Royal College of Surgeons in Ireland

Introduction Modern endourology relies on Ho: YAG lasers for definitive management of urolithiasis. Current safety data is drawn predominantly from Ho: YAG laser testing in animal tissue. We aim to evaluate and characterise the grades of iatrogenic human ureteral injury due to contact with a Ho: YAG laser at commonly used lithotripsy settings. Met...

Purpose Buccal mucosal grafts have a well-established role in urology regarding the management of ureteric stricture disease. Despite its established use as a graft material there is a lack of data on the mechanical properties of buccal mucosa. We aim to compare the passive mechanical properties of porcine buccal mucosa with the ureter. Materials...

Objectives To assess human in vivo intrarenal pressure (IRP) and peristaltic activity at baseline and after ureteric stent placement, using a narrow calibre pressure guidewire placed retrogradely in the renal pelvis. Patients and Methods A prospective, multi‐institutional study recruiting consenting patients undergoing ureteroscopy was designed wi...

Background The aim was to ascertain the impact of irrigation technique on human intrarenal pressure during retrograde intrarenal surgery. Methods A parallel randomized trial recruited patients across three hospital sites. Patients undergoing retrograde intrarenal surgery for renal stone treatment with an 11/13-Fr ureteral access sheath were alloca...

Microindentation of fresh biological tissues is necessary for the creation of 3D biomimetic models that accurately represent the native extracellular matrix microenvironment. However, tissue must first be precisely sectioned into slices. Challenges exist in the preparation of fresh tissue slices, as they can tear easily and must be processed rapidl...

The ureteric wall is a complex multi-layered structure. The ureter shows variation in passive mechanical properties, histological morphology and insertion forces along the anatomical length. Ureter mechanical properties also vary depending on the direction of tensile testing and the anatomical region tested. Compliance is greatest in the proximal u...

Microindentation of fresh biological tissues is necessary for the creation of 3D biomimetic models that accurately represent the native extracellular matrix microenvironment. However, tissue must first be precisely sectioned into slices. Challenges exist in the preparation of fresh tissue slices, as they can tear easily and must be processed rapidl...

Objectives To evaluate the pressure range generated in the human renal collecting system during ureteroscopy (URS), in a large patient sample, and to investigate a relationship between intrarenal pressure (IRP) and outcome. Patients and Methods A prospective multi‐institutional study was conducted, with ethics board approval; February 2022–March 2...

Paediatric urinary catheters are often necessary in critical care settings or to address congenital anomalies affecting the urogenital system. Iatrogenic injuries can occur during the placement of such catheters, highlighting the need for a safety device that can function in paediatric settings. Despite successful efforts to develop devices that im...

Cardiovascular disease is the leading cause of death worldwide, often associated with coronary artery occlusion. A common intervention for arterial blockage utilizes a vascular graft to bypass the diseased artery and restore downstream blood flow; however, current clinical options exhibit high long-term failure rates. Our goal was to develop an off...

Macromolecular components of the vascular extracellular matrix (ECM), particularly elastic fibers and collagen fibers, are critical for the proper physiological function of arteries. When the unique biomechanical combination of these fibers is disrupted, or in the ultimate extreme where fibers are completely lost, arterial disease can emerge. Bioen...

Cryopreservation is required to preserve the native properties of tissue for prolonged periods of time. In this study, we evaluate the impact that 4 different cryopreservation protocols have on porcine urethral tissue, to identify the method that best preserves the native properties of the tissue. The cryopreservation protocols include storage in c...

This study addresses a crucial gap in the literature by characterising the relationship between urethral tissue mechanics, composition and gross structure. We then utilise these data to develop a biomimetic urethral scaffold with physical properties that more accurately mimic the native tissue than existing gold standard scaffolds; small intestinal...

Background: The aim of this study is to systematically compare rates of erosion and chronic pain after mesh insertion for pelvic organ prolapse (POP) and stress urinary incontinence (SUI) surgery. Methods: A systematic electronic search was performed on studies that evaluated the incidence of erosion and chronic pain after mesh insertion for POP o...

Vascular tissue engineering is a field of regenerative medicine that restores tissue function to defective sections of the vascular network by bypass or replacement with a tubular, engineered graft. The tissue engineered vascular graft (TEVG) is comprised of a biodegradable scaffold, often combined with cells to prevent acute thrombosis and initiat...

Vascular tissue engineering (VTE) is aimed at developing regenerative vascular grafts to restore tissue function by bypassing or replacing defective arterial segments with tubular biodegradable scaffolds. Scaffolds are often combined with stem/progenitor cells to prevent acute thrombosis and initiate scaffold remodeling. However, there are limitati...

The success of tissue-engineered vascular graft (TEVG) predominantly relies on the selection of a suitable biomaterial and graft design. Natural biopolymer silk has shown great promise for various tissue-engineering applications. This study is the first to investigate Indian endemic non-mulberry silk (Antheraea assama-AA) - which inherits naturally...

The blood–brain barrier (BBB) has a significant contribution to homeostasis and protection of the CNS. However, it also limits the crossing of therapeutics and thereby complicates the treatment of CNS disorders. To overcome this limitation, the use of nanocarriers for drug delivery across the BBB has recently been exploited. Nanocarriers can utiliz...

Areas of disturbed shear that develop following arteriovenous fistula (AVF) creation are believed to trigger the onset of intimal hyperplasia (IH), leading to AVF dysfunction. The presence of helical flow can suppress the flow disturbances that lead to disturbed shear in other areas of the vasculature. However, the relationship between helical flow...

Objective Elastogenesis within the medial layer of the aortic wall involves a cascade of events orchestrated primarily by smooth muscle cells, including transcription of elastin and a cadre of elastin chaperone matricellular proteins, deposition and cross-linking of tropoelastin coacervates, and maturation of extracellular matrix fiber structures t...

This article presents an investigation into the mechanical properties of porcine mesocolon, small intestinal mesentery, fascia, and peritoneum tissues to generate a preliminary database of the mechanical characteristics of these tissues as surrogates for human tissue. No study has mechanically characterised porcine tissue correlates of the mesenter...

Vascular tissue engineering is an area of regenerative medicine that attempts to create functional replacement tissue for defective segments of the vascular network. One approach to vascular tissue engineering utilizes seeding of biodegradable tubular scaffolds with stem (and/or progenitor) cells wherein the seeded cells initiate scaffold remodelin...

Background: The urinary bladder and urethra comprise the lower urinary tracts. Pathological conditions that affect both structures necessitate reconstructive urological intervention with autologous tissue sources that cause neuromechanical and metabolic complications. Stem-cell therapies may offer an attractive alternative as they can replicate im...

Data on urethral catheter related injuries is sparse. In this study we aimed to characterise urethral diametric strain and urinary catheter inflation pressure thresholds that precede human urethral trauma during urethral catheterisation (UC). Human urethras were obtained from patients undergoing male to female gender reassignment surgery [(n = 9; a...

Objective: To evaluate the feasibility of a novel 'safety-valve' device for preventing catheter related urethral trauma during urethral catheterisation (UC). To assess the opinions of clinicians on the performance of the safety-valve device. Materials and methods: A validated prototype 'safety-valve' device for preventing catheter balloon inflat...

Autologous gastrointestinal tissue is the gold standard biomaterial for urinary tract reconstruction despite its long-term neuromechanical and metabolic complications. Regenerative biomaterials have been proposed as alternatives; however many are limited by a poor host derived regenerative response and deficient supportive elements for effective ti...

Objective: To evaluate the mechanical properties of gastrointestinal (GI) tissue segments and to compare them with the urinary bladder for urinary tract reconstruction. Methods: Urinary bladders and GI tissue segments were sourced from porcine models (n = 6, 7 months old [5 male; 1 female]). Uniaxial planar tension tests were performed on bladde...

Objective: Parameters other than maximum diameter that predict rupture of abdominal aortic aneurysms (AAAs) may be helpful for risk-benefit analysis in individual patients. The aim of this study was to characterize the biomechanical-structural characteristics associated with AAA walls to better identify the related mechanistic variables required f...

Autologous gastrointestinal tissue has remained the gold-standard reconstructive biomaterial in urology for >100 years. Mucus-secreting epithelium is associated with lifelong metabolic and neuromechanical complications when implanted into the urinary tract. Therefore, the availability of biocompatible tissue-engineered biomaterials such as extracel...

Objective/background: Carotid artery stenting (CAS) in calcified arteries carries a higher peri-operative risk. This study investigates the relationship between the stretching limits of carotid plaque samples and calcification in order to determine a stretch tolerance criterion for endovascular intervention. Methods: Seventeen carotid plaque sam...

Purpose: The purpose of this study is to determine the optimal target CT spatial resolution for accurately imaging abdominal aortic aneurysm (AAA) wall characteristics, distinguishing between tissue and calcification components, for an accurate assessment of rupture risk. Materials and methods: Ruptured and non-ruptured AAA-wall samples were acquir...

A vascular access (VA) is used to facilitate hemodialysis in patients that suffer from end-stage renal disease. However, they suffer from high failure rates due to non-maturation and venous stenosis, with intimal hyperplasia (IH) the underlying cause of both conditions. Abnormal hemodynamic profiles, which arise following VA creation, are believed...

Objective: To quantify user variability and manufacturer variability in urinary catheter anchoring balloon inflation pressure and to mitigate any significant variance by incorporating flow resistance into the anchoring balloon inflation process. Methods: Inflation of a urinary catheter anchoring balloon was performed at atmospheric pressure by d...

This study compares the mechanical properties of excised carotid and femoral human plaques and also develops a predictor of these properties based on plaque composition. Circumferential planar tension tests were performed on 24 carotid and 16 femoral plaque samples. Composition was characterised using Fourier transform infrared spectroscopy. Stretc...

Statement of significance: Calcification plays a fundamental role in plaque tissue mechanics and demonstrates a diverse range of material moduli properties. This work addresses the characterisation of the toughness properties in human carotid plaque tissue using a fracture mechanics approach. Toughness determines the energy required to propagate a...

Here, we review the in vitro models used to evaluate drug-coated endovascular technologies. The models are assessed in the context of representing the drug transport/uptake and mechanical properties of atherosclerotic peripheral vessels. Studies to date have incorporated a vessel-simulating hydrogel compartment to examine drug elution from endovasc...

Objective: To evaluate an alternative catheter labelling approach for 3-way catheters based on the drainage channel and irrigation channel cross-sectional area (CSA), which impacts catheter flow rate characteristics. Materials and methods: Three way 22Fr catheters from Bard (Bard Limited(TM)), Rusch Simplastic (Teleflex Medical(TM)), Dover (COVI...

Statement of significance: This study addresses a gap in current knowledge regarding the influence of plaque location, composition and morphology on the toughness of human femoral plaque tissue. Such information is of great importance to the continued improvement of endovascular treatments, particularly cutting balloon angioplasty (CBA), which req...

To investigate urethral diametric strain and threshold maximum inflation pressure for rupture during inadvertent inflation of a catheter's anchoring balloon in the urethra and to evaluate a novel safety device for preventing trauma based on these parameters. Inflation of a urethral catheter's anchoring balloon was performed in the bulbar urethra of...

Due to the limited number of experimental studies that mechanically characterise human atherosclerotic plaque tissue from the femoral arteries, a recent trend has emerged in current literature whereby one set of material data based on aortic plaque tissue is employed to numerically represent diseased femoral artery tissue. This study aims to genera...

Calcification is a marked pathological component in carotid artery plaque. Studies have suggested that calcification may induce regions of high stress concentrations therefore increasing the potential for rupture. However, the mechanical behaviour of the plaque under the influence of calcification is not fully understood. A method of accurately cha...

The failure of endovascular treatments of peripheral arterial disease represents a critical clinical issue. Specialised data are required to tailor such procedures to account for the mechanical response of the diseased femoral arterial tissue to medical device deployment. The purpose of this study is to characterise the mechanical response of ather...

The emergence of drug-eluting stents (DES) as a viable replacement for bare metal stenting has led to a significant decrease in the incidence of clinical restenosis. This is due to the transport of anti-restenotic drugs from within the polymer coating of a DES into the artery wall which arrests the cell cycle before restenosis can occur. The effica...

Recent experimental studies performed on human carotid plaques have focused on mechanical characterisation for the purpose of developing material models for finite element analysis without quantifying the tissue composition or relating mechanical behaviour to pre-operative classification. This study characterises the mechanical and biological prope...

This study assesses the suitability of developing a material for use in an experimental model of the carotid baroreceptors. Such a model could then be used in future studies to assess the impact of carotid artery stenting on hemodynamic stability. The material must exhibit a significant measurable electrical response to strain in a fashion analogou...