Publications
37 results found
Patrone L, Theivacumar NS, Dharmarajah B, et al., 2023, Target balloon-assisted antegrade and retrograde use of re-entry catheters in complex chronic total occlusions, Journal of Cardiovascular Development and Disease, Vol: 10, Pages: 1-11, ISSN: 2308-3425
Purpose, Retrograde recanalizations have gained increasing recognition in complex arterial occlusive disease. Re-entry devices are a well described adjunct for antegrade recanalizations. We present our experience with target balloon-assisted antegrade and retrograde recanalizations using re-entry devices in challenging chronic total occlusions. MATERIALS AND METHODS: We report data from a retrospective multicenter registry. Eligibility criteria included either antegrade or retrograde use of the OutbackTM or GoBackTM re-entry catheter in combination with a balloon as a target to accomplish wire passage, when conventional antegrade and retrograde recanalization attempts had been unsuccessful. Procedural outcomes included technical success (defined as wire passage though the occlusion and delivery of adjunctive therapy with <30% residual stenosis at final angiogram), safety (periprocedural complications, e.g., bleeding, vessel injury, or occlusion of the artery at the re-entry site, and distal embolizations), and clinical outcome (amputation-free survival and freedom from target lesion revascularization after 12-months follow-up). RESULTS: Thirty-six consecutive patients underwent target balloon-assisted recanalization attempts. Fourteen (39 %) patients had a history of open vascular surgery in the index limb. Fifteen patients were claudications (Rutherford Class 2 or 3, 21 presented with chronic limb threatening limb ischemia (Rutherford Class 4 to 6). The locations of the occlusive lesions were as follows: iliac arteries in 3 cases, femoropopliteal artery in 39 cases, and in below-the-knee arteries in 12 cases. In 15 cases, recanalization was attempted in multilevel occlusions. Retrograde access was attempted in 1 case in the common femoral artery, in the femoropopliteal segment in 10 cases, in below-the-knee arteries in 23 cases, and finally in 2 patients via the brachial artery. In 10 cases, the re-entry devices were inserted via the retrograde access site. Tech
Patrone L, Dharmarajah B, Korosoglou G, et al., 2022, Retrograde use of the Outback re-entry catheter in complex infrainguinal arterial recanalizations, JOURNAL OF VASCULAR SURGERY, Vol: 75, Pages: 177-+, ISSN: 0741-5214
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- Citations: 7
Patrone L, Dharmarajah B, Theivacumar S, et al., 2019, Retrograde Use of the Outback Re-entry Catheter in Complex Infrainguinal Arterial Recanalization, Fall Meeting of the Frank-J-Veith-International-Society / VEITH Symposium, Publisher: MOSBY-ELSEVIER, Pages: E130-E131, ISSN: 0741-5214
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- Citations: 1
Sung Y, Spagou K, Kafeza M, et al., 2018, Deep vein thrombosis exhibits characteristic serum and vein wall metabolic phenotypes in the inferior vena cava ligation mouse model, European Journal of Vascular and Endovascular Surgery, Vol: 55, Pages: 703-713, ISSN: 1078-5884
Deep vein thrombosis (DVT) is a major health problem, responsible for significant morbidity and mortality, and imposes a heavy economic burden to healthcare systems (1). Although most events resolve without complication through spontaneous lysis and recanalization, DVT can be complicated with life-threatening pulmonary embolism (2), while approximately one third of DVT patients develop post-thrombotic syndrome with swelling, pain, skin changes and/or venous ulceration (3).Treatment with anticoagulation prevents further thrombus extension, protects from pulmonary embolism and reduces the risk of chronic lower limb complications. Importantly, unnecessary treatment can result in bleeding. Therefore, accurate and reliable DVT diagnosis is essential. Currently, diagnosis relies on subjective clinical examination and ultrasound imaging (4). A number of biological markers have been investigated with variable results. D-dimer, the most widely used biomarker, is sensitive but lacks specificity (5, 6). Ongoing research efforts target the utility of alternative blood diagnostic biomarkers able to accurately diagnose DVT, guide length and type of treatment, and potentially identify patients who may benefit from more aggressive therapies than standard anticoagulation. New molecular technologies and methods have entered the scientific arena, offering the opportunity to revisit this important clinical need. Metabolic profiling has emerged as a new approach to investigate complex metabolic disease and enable precision medicine. Metabolomics is the comprehensive and systematic identification of the small molecules present in differential abundance in biofluids and are affected by various factors such as diet, lifestyle, genetics, disease, environmental factors and medications. Metabolic profiling approaches to characterizing the metabolome can be either targeted or untargeted. In targeted approaches specific metabolites, representative of suspected biological pathways, are analysed
Grant Y, Onida S, Dharmarajah B, et al., 2018, Exercise-induced median arcuate ligament syndrome in athletes, JOURNAL OF SPORTS MEDICINE AND PHYSICAL FITNESS, Vol: 58, Pages: 193-195, ISSN: 0022-4707
Cheung WK, Williams KJ, Christensen-Jeffries K, et al., 2017, A temporal and spatial analysis approach to automated segmentation of microbubble signals in contrast-enhanced ultrasound images: application to quantification of active vascular density in human lower limbs, Ultrasound in Medicine and Biology, Vol: 43, Pages: 2221-2234, ISSN: 0301-5629
Contrast-enhanced ultrasound (CEUS) using microbubble contrast agents has shown great promise in visualising and quantifying active vascular density. Most existing approaches for vascular density quantification using CEUS are calculated based on image intensity and are susceptible to confounding factors and imaging artefact. Poor reproducibility is a key challenge to clinical translation. In this study, a new automated temporal and spatial signal analysis approach is developed for reproducible microbubble segmentation and quantification of contrast enhancement in human lower limbs. The approach is evaluated in vitro on phantoms and in vivo in lower limbs of healthy volunteers before and after physical exercise. In this approach, vascular density is quantified based on the relative areas microbubbles occupy instead of their image intensity. Temporal features of the CEUS image sequences are used to identify pixels that contain microbubble signals. A microbubble track density (MTD) measure, the ratio of the segmented microbubble area to the whole tissue area, is calculated as a surrogate for active capillary density. In vitro results reveal a good correlation (r(2) = 0.89) between the calculated MTD measure and the known bubble concentration. For in vivo results, a significant increase (129% in average) in the MTD measure is found in lower limbs of healthy volunteers after exercise, with excellent repeatability over a series of days (intra-class correlation coefficient = 0.96). This compares to the existing state-of-the-art approach of destruction and replenishment analysis on the same patients (intra-class correlation coefficient ≤0.78). The proposed new approach shows great potential as an accurate and highly reproducible clinical tool for quantification of active vascular density.
Williams KJ, Sounderajah V, Dharmarajah B, et al., 2017, Simulated wound assessment using digital planimetry versus three-dimensional cameras: implications for clinical assessment., Annals of Vascular Surgery, Vol: 41, Pages: 235-240, ISSN: 1615-5947
BACKGROUND: Clinical management of wounds can benefit from objective measures of response to treatment. Wound surface area and volume are objective measures of wound healing. Using a synthetic wound model, we compare the accuracy and reproducibility of 2 commercially available 3-dimensional (3D) cameras against planimetry and water displacement. METHODS: Twelve ulcers of various sizes and colors were reproduced in modeling clay and cured. Five naive observers used digital planimetry, water displacement, Eykona camera (Fuel 3D, UK), and Silhouette camera (ARANZ, New Zealand) to measure the wounds. RESULTS: When compared with traditional planimetry, wound surface area measurement with Eykona and Silhouette tended to underestimate wounds by 1.7% and 3.7%, respectively. Spearman correlation coefficients were 0.94 (Eykona) and 0.92 (Silhouette). Intraclass correlations for planimetry and the 2 cameras were all 1. Eykona and Silhouette tended to underestimate wound volumes when compared with water displacement by 58% and 23%, respectively. Spearman correlation coefficients were 0.92 (Eykona) and 0.72 (Silhouette). Intraclass correlations for water displacement and the two cameras were all 1. DISCUSSION: Serial accurate objective area measurements are feasible as part of ongoing clinical assessment of wounds. 3D cameras are reliable but have not shown superior accuracy to manual planimetry, and financial concerns and IT integration may limit general clinical usage. Volume measurements of wounds are practicable as part of clinical care.
Moon KH, Dharmarajah B, Bootun R, et al., 2016, Comparison of microbubble presence in the right heart during mechanochemical and radiofrequency ablation for varicose veins, Phlebology, Vol: 32, Pages: 425-432, ISSN: 0268-3555
ObjectiveMechanochemical ablation is a novel technique for ablation of varicose veins utilising a rotating catheter and liquid sclerosant. Mechanochemical ablation and radiofrequency ablation have no reported neurological side-effect but the rotating mechanism of mechanochemical ablation may produce microbubbles. Air emboli have been implicated as a cause of cerebrovascular events during ultrasound-guided foam sclerotherapy and microbubbles in the heart during ultrasound-guided foam sclerotherapy have been demonstrated. This study investigated the presence of microbubbles in the right heart during varicose vein ablation by mechanochemical abaltion and radiofrequency abaltion.MethodsPatients undergoing great saphenous vein ablation by mechanochemical abaltion or radiofrequency ablation were recruited. During the ablative procedure, the presence of microbubbles was assessed using transthoracic echocardiogram. Offline blinded image quantification was performed using International Consensus Criteria grading guidelines.ResultsFrom 32 recruited patients, 28 data sets were analysed. Eleven underwent mechanochemical abaltion and 17 underwent radiofrequency abaltion. There were no neurological complications. In total, 39% (11/28) of patients had grade 1 or 2 microbubbles detected. Thirty-six percent (4/11) of mechanochemical abaltion patients and 29% (5/17) of radiofrequency ablation patients had microbubbles with no significant difference between the groups (p=0.8065).ConclusionA comparable prevalence of microbubbles between mechanochemical abaltion and radiofrequency ablation both of which are lower than that previously reported for ultrasound-guided foam sclerotherapy suggests that mechanochemical abaltion may not confer the same risk of neurological events as ultrasound-guided foam sclerotherapy for treatment of varicose veins.
Lane T, Bootun R, Dharmarajah B, et al., 2016, A multi-centre randomised controlled trial comparing radiofrequency and mechanical occlusion chemically assisted ablation of varicose veins - final results of the Venefit versus Clarivein for varicose veins trial, Phlebology, Vol: 32, Pages: 89-98, ISSN: 1433-3031
BACKGROUND: Endovenous thermal ablation has revolutionised varicose vein treatment. New non-thermal techniques such as mechanical occlusion chemically assisted endovenous ablation (MOCA) allow treatment of entire trunks with single anaesthetic injections. Previous non-randomised work has shown reduced pain post-operatively with MOCA. This study presents a multi-centre randomised controlled trial assessing the difference in pain during truncal ablation using MOCA and radiofrequency endovenous ablation (RFA) with six months' follow-up. METHODS: Patients undergoing local anaesthetic endovenous ablation for primary varicose veins were randomised to either MOCA or RFA. Pain scores using Visual Analogue Scale and number scale (0-10) during truncal ablation were recorded. Adjunctive procedures were completed subsequently. Pain after phlebectomy was not assessed. Patients were reviewed at one and six months with clinical scores, quality of life scores and duplex ultrasound assessment of the treated leg. RESULTS: A total of 170 patients were recruited over a 21-month period from 240 screened. Patients in the MOCA group experienced significantly less maximum pain during the procedure by Visual Analogue Scale (MOCA median 15 mm (interquartile range 7-36 mm) versus RFA 34 mm (interquartile range 16-53 mm), p = 0.003) and number scale (MOCA median 3 (interquartile range 1-5) versus RFA 4 mm (interquartile range 3-6.5), p = 0.002). 'Average' pain scores were also significantly less in the MOCA group; 74% underwent simultaneous phlebectomy. Occlusion rates, clinical severity scores, disease specific and generic quality of life scores were similar between groups at one and six months. There were two deep vein thromboses, one in each group. CONCLUSION: Pain secondary to truncal ablation is less painful with MOCA than RFA with similar short-term technical, quality of life and safety outcomes.
Bootun R, Lane TRA, Dharmarajah B, et al., 2016, Intra-procedural pain score in a randomised controlled trial comparing mechanochemical ablation to radiofrequency ablation: The Multicentre Venefit (TM) versus ClariVein (R) for varicose veins trial, PHLEBOLOGY, Vol: 31, Pages: 61-65, ISSN: 0268-3555
Seager MJ, Busuttil A, Dharmarajah B, et al., 2015, Editor's choice – a systematic review of endovenous stenting in chronic venous disease secondary to iliac vein obstruction, European Journal of Vascular and Endovascular Surgery, Vol: 51, Pages: 100-120, ISSN: 1532-2165
Seager MJ, Dharmarajah B, Davies EB, et al., 2015, The use of functional imaging in the diagnosis of carotid patch infection, VASCULAR, Vol: 23, Pages: 542-544, ISSN: 1708-5381
Mandavia R, Dharmarajah B, Qureshi MI, et al., 2015, The role of cost-effectiveness for vascular surgery service provision in the United Kingdom, JOURNAL OF VASCULAR SURGERY, Vol: 61, Pages: 1331-1339, ISSN: 0741-5214
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- Citations: 3
Bootun R, Lane TRA, Dharmarajah B, et al., 2015, Intra-procedural pain score in a randomised controlled trial comparing mechanochemical ablation to radiofrequency ablation: the multicentre Venefittm Versus Clarivein® for Varicose Veins (VVCVV) trial, Annual Meeting of the Society-of-Academic-and-Research-Surgery (SARS(, Publisher: WILEY-BLACKWELL, Pages: 4-4, ISSN: 0007-1323
Dharmarajah B, McKinnon TA, Keravnou C, et al., 2015, Thrombus dissolution using contrast enhanced ultrasound in an in-vitro model of acute deep vein thrombosis, Annual Meeting of the Society-of-Academic-and-Research-Surgery (SARS(, Publisher: WILEY-BLACKWELL, Pages: 37-38, ISSN: 0007-1323
Dharmarajah B, Hoon K-H, Bootun R, et al., 2015, Assessment of acoustic reflectors in the right heart during mechanochemical and radiofrequency ablation of the great saphenous vein, Annual Meeting of the Society-of-Academic-and-Research-Surgery (SARS(, Publisher: WILEY-BLACKWELL, Pages: 10-10, ISSN: 0007-1323
Dharmarajah B, Sounderajah V, Rowland SP, et al., 2015, Aging techniques for deep vein thrombosis: a systematic review, Phlebology, Vol: 30, Pages: 77-84, ISSN: 1433-3031
Deep vein thrombosis is common with an incidence of 1 in 1000. Acute thrombus removal for extensive proximal deep vein thrombosis using catheter-directed techniques highlights the need for accurate assessment of thrombus age. This systematic review summarises experimental and clinical evidence of imaging techniques for aging deep vein thrombosis. Ultrasound elastography and magnetic resonance imaging were highlighted as the most studied imaging modalities. Elastography was shown to distinguish between acute and chronic clots, despite demonstrating difficulty in accurate aging of clots older than 10 days in rat models. Elastography is noted as a feasible adjunct to current first-line imaging for deep vein thrombosis using duplex ultrasonography. Combinations of magnetic resonance imaging techniques can identify acute, sub-acute and chronic thrombi using endogenous contrast agents and provide objective standardisation of the diagnostic process, with reduced onus upon operator dependency. Further validation is required of these novel imaging techniques prior to clinical implementation for deep vein thrombosis aging.
Bootun R, Lane TRA, Dharmarajah B, et al., 2015, Intra-procedural pain score in a randomised controlled trial comparing mechanochemical ablation to radiofrequency ablation: the Multicentre Venefit™ versus ClariVein® for Varicose Veins (VVCVV) trial, BRITISH JOURNAL OF SURGERY, Vol: 102, Pages: 2-3, ISSN: 0007-1323
Moon K-H, Dharmarajah B, Bootun R, et al., 2015, Comparison of microbubble presence in the right heart during mechanochemical and radiofrequency ablation for varicose veins, BRITISH JOURNAL OF SURGERY, Vol: 102, Pages: 18-18, ISSN: 0007-1323
Dharmarajah B, McKinnon TA, Keravnou C, et al., 2015, Contrast-Enhanced Ultrasound for Thrombus Dissolution in an In Vitro Model of Acute Deep Venous Thrombosis., J Vasc Surg Venous Lymphat Disord, Vol: 3
Mandavia R, Qureshi MI, Dharmarajah B, et al., 2014, Safety of Carotid Intervention Following Thrombolysis in Acute Ischaemic Stroke, EUROPEAN JOURNAL OF VASCULAR AND ENDOVASCULAR SURGERY, Vol: 48, Pages: 505-512, ISSN: 1078-5884
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- Citations: 14
Rowland SP, Dharmarajah B, Moore HM, et al., 2014, Venous injuries in pediatric trauma: Systematic review of injuries and management, JOURNAL OF TRAUMA AND ACUTE CARE SURGERY, Vol: 77, Pages: 356-363, ISSN: 2163-0755
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- Citations: 10
Rowland SP, Dharmarajah B, Moore HM, et al., 2014, Inferior Vena Cava Filters for Prevention of Venous Thromboembolism in Obese Patients Undergoing Bariatric Surgery: A Systematic Review., Annals of Surgery, ISSN: 1528-1140
Objective: The use of inferior vena cava (IVC) filters for prevention of venous thromboembolism (VTE) in bariatric surgery is a contentious issue. We aim to review the evidence for the use of IVC filters in bariatric surgical patients, describe trends in practice, and discuss challenges in developing evidence-based guidelines.Background: The incidence of VTE in modern bariatric procedures with traditional methods of thromboprophylaxis, such as sequential calf compression devices and perioperative low molecular weight heparin, is approximately 2%.Methods: A systematic review of the literature was conducted according to PRISMA guidelines. We searched Medline up until July 2013 with the terms "bariatric filter" and "gastric bypass filter." Two investigators independently screened search results according to an agreed list of eligibility criteria.Results: Eighteen studies were included. There were no randomized controlled trials. Data from controlled cohort studies suggest that those who undergo IVC filter insertion preoperatively may be at higher risk of developing deep vein thrombosis (DVT) and pulmonary embolism (PE). A small cohort of patients with multiple risk factors for VTE benefitted from reduced PE-related mortality after preoperative IVC filter insertion. Data from 12 case series reporting VTE outcomes from a total of 497 patients who underwent preoperative IVC filter insertion demonstrated DVT rates of 0% to 20.8% and PE rates ranging from 0% to 6.4%.Conclusions: Published data reporting the safety and efficacy of IVC filter use in bariatric surgical patients is highly heterogeneous. There is no evidence to suggest that the potential benefits of IVC filters outweigh the significant risks of therapy.
Dharmarajah B, Thapar A, Salem J, et al., 2014, Decision making in symptomatic moderate carotid atherosclerosis: a survey of uk vascular surgeons and stroke physicians, Annual Meeting of the Society-of-Academic-and-Research-Surgery, Publisher: WILEY-BLACKWELL, Pages: 37-38, ISSN: 0007-1323
Dharmarajah B, McKinnon T, Leen ELS, et al., 2014, Sonothrombolysis - an in vitro and in-vivo study of thrombus dissolution using contrast enhanced ultrasound, Annual Meeting of the Society-of-Academic-and-Research-Surgery, Publisher: WILEY-BLACKWELL, Pages: 40-40, ISSN: 0007-1323
Dharmarajah B, Lane TRA, Moore HM, et al., 2014, The Future of Phlebology in Europe, PHLEBOLOGY, Vol: 29, Pages: 181-185, ISSN: 0268-3555
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- Citations: 2
Mandavia R, Qureshi MI, Davies AH, 2014, Safety of carotid surgery and intervention following thrombolysis in acute ischaemic stroke, Annual Meeting of the Society-of-Academic-and-Research-Surgery, Publisher: WILEY-BLACKWELL, Pages: 51-52, ISSN: 0007-1323
Dharmarajah B, Thapar A, Salem J, et al., 2014, Impact of risk scoring on decision-making in symptomatic moderate carotid atherosclerosis, BRITISH JOURNAL OF SURGERY, Vol: 101, Pages: 475-480, ISSN: 0007-1323
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- Citations: 4
Lane TRA, Dharmarajah B, Kelleher D, et al., 2013, Short-term gain for long-term pain? Which patients should be treated and should we ration?, PHLEBOLOGY, Vol: 28, Pages: 148-152, ISSN: 0268-3555
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- Citations: 5
Thapar A, Shalhoub J, Dharmarajah B, et al., 2013, Should we stop testing for asymptomatic carotid atherosclerosis?, JOURNAL OF NEUROINTERVENTIONAL SURGERY, Vol: 5, Pages: 94-96, ISSN: 1759-8478
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- Citations: 3
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