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1.
Jpn J Radiol ; 41(10): 1104-1116, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37071248

ABSTRACT

Whilst obesity and visceral adipose tissue (VAT) have been reported to be associated with an increased risk of severe AP, the established predictive scoring systems have not yet encompassed the impact of obesity or visceral adiposity. In the acute setting, computed tomography (CT) is often performed to assess AP severity and associated complications. With the added benefit of quantifying body fat distribution, it can be opportunistically used to quantify visceral adiposity and assess its relationship with the course of AP. This systematic review identified fifteen studies evaluating the relationship between visceral adiposity measured on CT and the severity of presentations of acute pancreatitis from January 2000 to November 2022. The primary outcome was to assess the relationship between CT quantified VAT and AP severity. The secondary outcomes were to assess the impact of VAT on patients developing local and systemic complications associated with AP. Whilst ten studies showed there was a significant correlation between an increased VAT and AP severity, five studies found otherwise. The majority of current literature demonstrate a positive correlation between increased VAT and AP severity. CT quantification VAT is a promising prognostic indicator with the potential to guide initial management, prompt more aggressive treatment measures or earlier re-evaluation and to aid disease prognostication in patients with acute pancreatitis.


Subject(s)
Pancreatitis , Humans , Pancreatitis/complications , Pancreatitis/diagnostic imaging , Adiposity , Acute Disease , Tomography, X-Ray Computed , Obesity/complications , Intra-Abdominal Fat/diagnostic imaging
2.
Carbohydr Polym ; 302: 120308, 2023 Feb 15.
Article in English | MEDLINE | ID: mdl-36604036

ABSTRACT

Hydrogels with more than one mode of crosslinking have gained interest due to improved control over hydrogel properties such as mechanical strength using multiple stimuli. In this work, sodium alginate was covalently conjugated onto thermoresponsive polyurethanes to prepare hybrid polymers (EPC-Alg) that are responsive to both temperature and Ca2+, forming orthogonally crosslinked hydrogels which are non-toxic to cells. Notably, the crosslinks are fully reversible, allowing for gel strength to be modulated via selective removal of either stimulus, or complete deconstruction of the hydrogel network by removing both stimuli. Higher alginate fractions increased the hydrophilicity and Ca2+ response of the EPC-Alg hydrogel, enabling tunable modulation of the thermal stability, stiffness and gelation temperatures. The EPC-Alg hydrogel could sustain protein release for a month and encapsulate neural spheroids with high cell viability after 7-day culture, demonstrating feasibility towards 3D cell encapsulation in cell-based biomedical applications such as cell encapsulation and cell therapy.


Subject(s)
Alginates , Cell Encapsulation , Hydrogels/pharmacology
3.
Chem Asian J ; 17(20): e202200628, 2022 Oct 17.
Article in English | MEDLINE | ID: mdl-35977910

ABSTRACT

Supramolecular hydrogels have attracted considerable interest due to their unique stimuli-responsive and self-healing properties. However, these hydrogel systems are usually achieved by covalent grafting of supramolecular units onto the polymer backbone, which in turn limits their reprocessability. Herein, we prepared a supramolecular hydrogel system by forming dynamic covalent crosslinks between 4-carboxyphenylboronic acid (CPBA) and polyvinyl alcohol (PVA). The system was then further crosslinked with either calcium ions or branched polyethylenimine (PEI) to generate hydrogels with distinctly different properties. Incorporation of calcium ions resulted in the formation of hydrogels with higher storage modulus of 7290 Pa but without self-healing properties. On the other hand, PEI-crosslinked hydrogel (PVA-CPBA-PEI) exhibited >2000% critical strain value, demonstrated high stability over 52 days and showed sustained antibacterial effect. A combination of supramolecular interactions and dynamic covalent crosslinks can be an alternate strategy to fabricate next-generation hydrogel materials.


Subject(s)
Hydrogels , Polyvinyl Alcohol , Polymers , Polyethyleneimine , Calcium , Anti-Bacterial Agents
4.
Biomacromolecules ; 23(9): 3698-3712, 2022 09 12.
Article in English | MEDLINE | ID: mdl-35998618

ABSTRACT

Injectable hydrogels have gained considerable attention, but they are typically mechanically weak and subject to repeated physiological stresses in the body. Herein, we prepared polyurethane diacrylate (EPC-DA) hydrogels, which are injectable and can be photocrosslinked into fatigue-resistant implants. The mechanical properties can be tuned by changing photocrosslinking conditions, and the hybrid-crosslinked EPC-DA hydrogels exhibited high stability and sustained release properties. In contrast to common injectable hydrogels, EPC-DA hydrogels exhibited excellent antifatigue properties with >90% recovery during cyclic compression tests and showed shape stability after application of force and immersion in an aqueous buffer for 35 days. The EPC-DA hydrogel formed a shape-stable hydrogel depot in an ex vivo porcine skin model, with establishment of a temporary soft gel before in situ fixing by UV crosslinking. Hybrid crosslinking using injectable polymeric micelles or nanoparticles may be a general strategy for producing hydrogel implants resistant to physiological stresses.


Subject(s)
Hydrogels , Mechanical Phenomena , Animals , Fatigue , Hydrogels/pharmacology , Micelles , Polymers , Swine
5.
ANZ J Surg ; 92(9): 2224-2228, 2022 09.
Article in English | MEDLINE | ID: mdl-35751848

ABSTRACT

BACKGROUND: Splanchnic vein thrombosis (SVT) is an uncommon yet potentially life-threatening manifestation of venous thromboembolism. The aim of this study was to present a retrospective analysis of a cohort of Western Australian patients diagnosed with SVT on imaging study, and a review of the literature surrounding the aetiology, location, anticoagulation treatment and outcomes of SVT. METHODS: All patients diagnosed with SVT over a five-year period from 2015 to 2020 in three tertiary hospitals in Western Australia were identified by using an electronic search engine of imaging reports. Collected data included patient demographics and co-morbidity, presentation data, location of thrombus, aetiology of thrombus, treatment with anti-coagulation, length of stay and outcome data including mortality. RESULTS: A total of 164 patients met inclusion criteria. The 90-day mortality was 20.1%; 64% of whom were those with portal vein thrombosis. Aetiology was grouped into haematological conditions (4 patients), non-haematological conditions (130 patients), a combination of factors (17 patients) and idiopathic (13 patients). The majority of deaths were due to malignancy, severe pancreatitis or decompensated liver cirrhosis. CONCLUSION: Whilst the prevalence of SVT is rising with the increase in accessibility to radiological studies, it remains a diagnostic and therapeutic challenge for clinicians. With no consensus guidelines available to direct treatment, the management of patients with SVT should be individualized and considered carefully. The potential complications of venous thrombosis, SVT recurrence or extension and the risk of bleeding need to be evaluated before the commencement of anticoagulation therapy.


Subject(s)
Splanchnic Circulation , Venous Thrombosis , Anticoagulants , Australia/epidemiology , Humans , Retrospective Studies , Venous Thrombosis/diagnosis , Venous Thrombosis/epidemiology , Venous Thrombosis/etiology
6.
Front Bioeng Biotechnol ; 10: 864372, 2022.
Article in English | MEDLINE | ID: mdl-35433644

ABSTRACT

Temperature-responsive hydrogels, or thermogels, are a unique class of biomaterials that show facile and spontaneous transition from solution to gel when warmed. Their high biocompatibility, and ease of formulation with both small molecule drugs and biologics have made these materials prime candidates as injectable gel depots for sustained local drug delivery. At present, controlling the kinetics and profile of drug release from thermogels is achieved mainly by varying the ratio of hydrophobic: hydrophilic composition and the polymer molecular weight. Herein, we introduce polymer branching as a hitherto-overlooked polymer design parameter that exhibits profound influences on the rate and profile of drug release. Through a family of amphiphilic thermogelling polymers with systematic variations in degree of branching, we demonstrate that more highly-branched polymers are able to pack less efficiently with each other during thermogel formation, with implications on their physical properties and stability towards gel erosion. This in turn resulted in faster rates of release for both encapsulated small molecule hydrophobic drug and protein. Our results demonstrate the possibility of exploiting polymer branching as a hitherto-overlooked design parameter for tailoring the kinetics and profile of drug release in injectable thermogel depots.

7.
Biomaterials ; 280: 121262, 2022 01.
Article in English | MEDLINE | ID: mdl-34810039

ABSTRACT

Vitreous endotamponades play essential roles in facilitating retina recovery following vitreoretinal surgery, yet existing clinically standards are suboptimal as they can cause elevated intra-ocular pressure, temporary loss of vision, and cataracts while also requiring prolonged face-down positioning and removal surgery. These drawbacks have spurred the development of next-generation vitreous endotamponades, of which supramolecular hydrogels capable of in-situ gelation have emerged as top contenders. Herein, we demonstrate thermogels formed from hyper-branched amphiphilic copolymers as effective transparent and biodegradable vitreous endotamponades for the first time. These hyper-branched copolymers are synthesised via polyaddition of polyethylene glycol, polypropylene glycol, poly(ε-caprolactone)-diol, and glycerol (branch inducing moiety) with hexamethylene diisocyanate. The hyper-branched thermogels are injected as sols and undergo spontaneous gelation when warmed to physiological temperatures in rabbit eyes. We found that polymers with an optimal degree of hyper-branching showed excellent biocompatibility and was able to maintain retinal function with minimal atrophy and inflammation, even at absolute molecular weights high enough to cause undesirable in-vivo effects for their linear counterparts. The hyper-branched thermogel is cleared naturally from the vitreous through surface hydrogel erosion and negates surgical removal. Our findings expand the scope of polymer architectures suitable for in-vivo intraocular therapeutic applications beyond linear constructs.


Subject(s)
Endotamponade , Vitreous Body , Animals , Hydrogels , Molecular Weight , Polyesters , Polyethylene Glycols , Rabbits , Vitreous Body/surgery
10.
Ann Vasc Surg ; 73: 511-514, 2021 May.
Article in English | MEDLINE | ID: mdl-33515660

ABSTRACT

OBJECTIVE: We describe the case of lower limb unilateral swelling due to a cystic mass (adventitial cystic disease) compressing on the common femoral vein. This was misdiagnosed as a deep vein thrombosis on both computed tomography venography and Doppler ultrasound. METHOD: We describe the diagnostic pathways and surgical excision of this venous adventitial cyst of the femoral vein. CONCLUSION: Venous adventitial cysts are a rare occurrence and diagnosis remains difficult. It often presents clinically as a Deep Vein Thrombosis (DVT). Suspicions should be raised should symptoms persist despite appropriate DVT management. Surgical management include endovascular, minimally invasive procedures, and complete evacuation of the mucoid cyst with excision of the cystic wall.


Subject(s)
Adventitia/diagnostic imaging , Cysts/diagnostic imaging , Femoral Vein/diagnostic imaging , Phlebography , Ultrasonography, Doppler , Venous Thrombosis/diagnostic imaging , Adventitia/surgery , Computed Tomography Angiography , Cysts/surgery , Diagnostic Errors , Female , Femoral Vein/surgery , Humans , Middle Aged , Predictive Value of Tests , Treatment Outcome
11.
J Vasc Access ; 22(2): 254-260, 2021 Mar.
Article in English | MEDLINE | ID: mdl-32605406

ABSTRACT

AIMS: To compare the rates of infections (peritonitis and exit site infections) in patients undergoing non-buried versus buried peritoneal dialysis catheterisation for end-stage renal failure. METHODS: A retrospective review of all patients who underwent peritoneal dialysis catheter placement by one primary surgeon between January 2008 and August 2019. Information collected included, catheter characteristics, immediate post-operative complications, date of catheter exteriorisation, date of peritoneal dialysis commencement, rate of successful catheter function at initiation of peritoneal dialysis and rates of catheter-related complications (i.e. infection, revision status and obstruction). RESULTS: 110 peritoneal dialysis catheters were inserted (43 non-buried and 67 buried peritoneal dialysis catheters). The non-buried group was associated with a higher proportion acquiring an infection than the buried group (15% vs 30%, p = 0.054). Patients with buried catheters also had a 72% and 65% decreased likelihood of experiencing a catheter-related infection and peritonitis, respectively, over time compared to patients with non-buried catheters in the unadjusted (crude incidence rate ratio 0.28, 95% confidence interval 0.11, 0.70; P = 0.003). The proportion of catheter function at first use was 85% in the non-buried group and 78% in the buried group. Patients with non-buried versus buried catheters had similar proportions of complications, including: obstructions (25.6% vs 20.9%, p = 0.770), herniation (7.0% vs 4.0%, p = 0.327) and leaks (7.0% vs 1.5%, p = 0.134). CONCLUSION: The use of the buried peritoneal dialysis catheter technique as compared to the standard technique has revealed fewer overall catheter-related infections, particularly episodes of peritonitis and similar rates of mechanical complications in our series. In addition to that, the other benefits of buried peritoneal dialysis catheters such as lower healthcare cost, patient convenience and a viable option for patients in remote communities should prompt physicians to continue assessing suitable candidates for buried peritoneal dialysis catheters.


Subject(s)
Catheterization/instrumentation , Catheters, Indwelling , Peritoneal Dialysis/instrumentation , Adult , Aged , Aged, 80 and over , Catheter-Related Infections/microbiology , Catheterization/adverse effects , Catheterization/mortality , Equipment Design , Female , Humans , Male , Middle Aged , Peritoneal Dialysis/adverse effects , Peritoneal Dialysis/mortality , Peritonitis/microbiology , Retrospective Studies , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome
12.
J Vasc Access ; 21(6): 1029-1033, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32364814

ABSTRACT

Peritoneal dialysis is a renal substitutive therapy used in an increasing number of patients with end-stage renal failure as it allows greater freedom to perform daily activities. Peritoneal dialysis catheter obstruction is a significant non-infectious complication of peritoneal dialysis. We describe three cases of peritoneal dialysis catheter obstruction with complete fibrin casts, its surgical management and a review of the literature in management techniques and have proposed an algorithm to guide clinical practise when a complete intraluminal peritoneal dialysis catheter obstruction is suspected.


Subject(s)
Catheter Obstruction/etiology , Catheters, Indwelling/adverse effects , Fibrin/metabolism , Kidney Failure, Chronic/therapy , Peritoneal Dialysis/adverse effects , Peritoneal Dialysis/instrumentation , Therapeutic Irrigation , Vascular Surgical Procedures , Aged , Humans , Male , Middle Aged , Treatment Outcome
13.
Surg Res Pract ; 2020: 8970759, 2020.
Article in English | MEDLINE | ID: mdl-32232118

ABSTRACT

BACKGROUND: Several studies have reported worse outcomes in women compared to men after endovascular aneurysm repair (EVAR). This study aimed to evaluate sex-specific short-term and 5-year outcomes after EVAR. METHODS: A total of 409 consecutive patients underwent elective EVAR from 2004 to 2017 at two tertiary hospitals in Western Australia. Baseline, intraoperative, and postoperative variables were examined retrospectively according to sex. The primary outcome was 30-day mortality (death within 30 days after EVAR). Secondary outcomes were 30-day composite endpoint, length of stay after EVAR, 5-year survival, freedom from reintervention, residual aneurysm size after EVAR, and major adverse event rate at 5-year follow-up. RESULTS: A cohort of 409 patients, comprising 57 women (14%) and 352 men (86%), was analysed. Female patients were older (median age, 76.8 versus 73.5 years, p=0.017). Male patients were more likely to be past smokers (40.9% versus 22.8%, p=0.017). Male patients were more likely to be past smokers (40.9% versus 22.8%, p=0.017). Male patients were more likely to be past smokers (40.9% versus 22.8%, p=0.017). Male patients were more likely to be past smokers (40.9% versus 22.8%, p=0.017). Male patients were more likely to be past smokers (40.9% versus 22.8%, p=0.017). Male patients were more likely to be past smokers (40.9% versus 22.8%, p=0.017). Male patients were more likely to be past smokers (40.9% versus 22.8%. CONCLUSION: This study found no significant differences in 30-day and 5-year outcomes between female and male patients treated with EVAR, implying that EVAR remains a safe treatment choice for female patients.

14.
Ann Vasc Surg ; 68: 568.e17-568.e21, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32278871

ABSTRACT

BACKGROUND: Peripheral atherectomy is utilized in the treatment of heavily calcified plaques from peripheral arterial lesions. Commonly reported complications include access site injury, perforations, dissections, embolism, and retroperitoneal hemorrhage. METHODS: We report the case of a 74-year-old Caucasian male who developed a 50 × 43 × 40-mm saccular pseudoaneurysm in the native mid-superficial femoral artery after TurboHawk atherectomy. RESULTS: We describe the diagnostic steps in identifying this complication secondary to directional atherectomy and the successful treatment of this pseudoaneurysm using a Viabahn stent graft. CONCLUSIONS: Pseudoaneurysm is a rare complication associated with the procedure which must be followed up with repeat imaging. Symptoms such as limb pain or swelling or increase in the size of pseudoaneurysm should prompt timely assessment of atherectomy site. Stenting with a Viabahn stent has proven to be a viable and successful treatment option.


Subject(s)
Aneurysm, False/etiology , Atherectomy/adverse effects , Femoral Artery/injuries , Vascular System Injuries/etiology , Aged , Aneurysm, False/diagnostic imaging , Aneurysm, False/therapy , Angioplasty, Balloon/instrumentation , Femoral Artery/diagnostic imaging , Humans , Male , Stents , Time Factors , Treatment Outcome , Vascular System Injuries/diagnostic imaging , Vascular System Injuries/therapy
15.
Clin Nurs Res ; 29(7): 460-468, 2020 09.
Article in English | MEDLINE | ID: mdl-31709812

ABSTRACT

The diagnosis of childhood cancer not only affects the life of the child but also impacts the lives of the caregivers as well. This study aims to explore the caregiving stress, coping strategies, and support needs of mothers caring for children/adolescents with cancer during the active treatment phase. Individual semi-structured interviews were conducted, and two authors independently and thematically analyzed data. Caregiving mothers went through a process of emotional changes and a change in lifestyles when their children were diagnosed with cancer and undergoing treatments. It is important to ensure that caregiving mothers of children/adolescents with cancer are well supported by family, friends, and healthcare professionals. Healthcare professionals can develop informational booklets on cancer treatment protocols and work together with mothers. Parent support groups and plans for psychoeducational and spiritual care programs for mothers as forms of informational and emotional support may also be established.


Subject(s)
Caregivers , Neoplasms , Adaptation, Psychological , Adolescent , Child , Female , Humans , Mothers , Neoplasms/therapy , Parents , Social Support , Stress, Psychological
16.
Vasc Specialist Int ; 35(3): 174-179, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31620405

ABSTRACT

Segmental arterial mediolysis (SAM) is a rare noninflammatory, nonarteriosclerotic arteriopathy of an unknown etiology. It most commonly affects the medium-sized vessels of the abdomen and is characterized by the disruption of the arterial medial layer. Although histological confirmation remains the gold standard in diagnosis, the use of computed tomography angiography (CTA) has greatly aided the diagnosis and surveillance of SAM. Given its rarity and angiographic similarities to other vasculopathies, the diagnosis of SAM can be challenging and is often missed. We describe the case of a 46-year-old male patient who presented to our institution with abdominal pain and multiple foci of intra-abdominal arterial dissections on CTA. We report the acute management via endovascular intervention and review the literature with respect to the diagnosis and management of this rare condition. SAM remains an uncommon yet significant disease process requiring prompt and accurate diagnosis. Initiation of immediate treatment is crucial, given the knowledge gap about its natural progression.

17.
Case Rep Vasc Med ; 2019: 6853135, 2019.
Article in English | MEDLINE | ID: mdl-31093417

ABSTRACT

Infrarenal abdominal aortic dissections (IAAD) are exceedingly rare, accounting for 1-4% of all aortic dissections. The evidence is scarce on how to best manage IAAD when they become symptomatic. Two main interventional approaches exist, open surgery and the endovascular approach. Conventional stent-graft systems make it difficult to treat nonaneurysmal aortic disease due to limb competition in a narrow distal aorta. Thus, we present a novel use of the Endologix Anatomical Fixation 2 (AFX2) Abdominal Aortic Aneurysm (AAA) endograft system for the treatment of four patients with IAAD. We also highlight an individual case study that was treated with an alternative endovascular approach and the complications that followed. This was to highlight and compare our successful experience with Endologix AFX2 AAA endograft system. There were multiple benefits for choosing this stent-graft; however the main advantage is its suitability in the narrow distal aorta. Our aim was to highlight an alternative endovascular approach for the successful treatment of a rare, challenging, and potentially fatal pathology.

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