Imperial College London

DR BRAHMAN DHARMARAJAH

Faculty of MedicineDepartment of Surgery & Cancer

Honorary Clinical Senior Lecturer
 
 
 
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Contact

 

b.dharmarajah

 
 
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Location

 

Charing Cross HospitalCharing Cross Campus

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Summary

 

Publications

Publication Type
Year
to

35 results found

Patrone L, Dharmarajah B, Theivacumar S, Stehno O, Malina M, Blessing Eet 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

Conference paper

Sung Y, Spagou K, Kafeza M, Kyriakides M, Dharmarajah B, Shalhoub J, Diaz JA, Wakefield T, Holmes E, Davies Aet 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

Journal article

Grant Y, Onida S, Dharmarajah B, Davies EB, Davies AHet 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

Journal article

Cheung WK, Williams KJ, Christensen-Jeffries K, Dharmarajah B, Eckersley RJ, Davies AH, Tang M-Xet 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.

Journal article

Williams KJ, Sounderajah V, Dharmarajah B, Thapar A, Davies AHet 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.

Journal article

Moon KH, Dharmarajah B, Bootun R, Lim CS, Lane TRA, Moore HM, Sritharan K, Davies AHet 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.

Journal article

Lane T, Bootun R, Dharmarajah B, Lim CS, Najem M, Renton S, Sritharan K, Davies AHet 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.

Journal article

Bootun R, Lane TRA, Dharmarajah B, Lim CS, Najem M, Renton S, Sritharan K, Davies AHet 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

Journal article

Seager MJ, Busuttil A, Dharmarajah B, Davies AHet 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

Journal article

Seager MJ, Dharmarajah B, Davies EB, Davies AH, Franklin IJet al., 2015, The use of functional imaging in the diagnosis of carotid patch infection, VASCULAR, Vol: 23, Pages: 542-544, ISSN: 1708-5381

Journal article

Mandavia R, Dharmarajah B, Qureshi MI, Davies AHet 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

Journal article

Dharmarajah B, Hoon K-H, Bootun R, Lim CS, Lane TRA, Moore HM, Sritharan K, Davies AHet 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

Conference paper

Bootun R, Lane TRA, Dharmarajah B, Lim CS, Najem M, Renton S, Sritharan K, Davies AHet al., 2015, Intra-procedural pain score in a randomised controlled trial comparing mechanochemical ablation to radiofrequency ablation: the multicentre Venefittm Versus Clarivein (R) 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

Conference paper

Dharmarajah B, McKinnon TA, Keravnou C, Averkiou M, Laffan MA, Leen ELS, Davies AHet 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

Conference paper

Dharmarajah B, Sounderajah V, Rowland SP, Leen ELS, Davies AHet 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.

Journal article

Moon K-H, Dharmarajah B, Bootun R, Lim CS, Lane TRA, Moore HM, Sritharan K, Davies AHet 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

Journal article

Bootun R, Lane TRA, Dharmarajah B, Lim CS, Najem M, Renton S, Sritharan K, Davies AHet al., 2015, 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 (VVCVV) trial, BRITISH JOURNAL OF SURGERY, Vol: 102, Pages: 2-3, ISSN: 0007-1323

Journal article

Dharmarajah B, McKinnon TA, Keravnou C, Averkiou MA, Leen ELS, Davies AHet 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

Journal article

Mandavia R, Qureshi MI, Dharmarajah B, Head K, Davies AHet 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

Journal article

Rowland SP, Dharmarajah B, Moore HM, Dharmarajah K, Davies AHet 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

Journal article

Rowland SP, Dharmarajah B, Moore HM, Lane TR, Cousins J, Ahmed AR, Davies AHet 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.

Journal article

Dharmarajah B, Lane TRA, Moore HM, Neumann HAM, Rabe E, Wittens CHA, Davies AHet al., 2014, The Future of Phlebology in Europe, PHLEBOLOGY, Vol: 29, Pages: 181-185, ISSN: 0268-3555

Journal article

Dharmarajah B, McKinnon T, Leen ELS, Wakefield TR, Davies AHet 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

Conference paper

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

Conference paper

Dharmarajah B, Thapar A, Salem J, Lane TRA, Leen ELS, Davies AHet 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

Conference paper

Dharmarajah B, Thapar A, Salem J, Lane TRA, Leen ELS, Davies AHet 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

Journal article

Thapar A, Shalhoub J, Dharmarajah B, Davies AHet al., 2013, Should we stop testing for asymptomatic carotid atherosclerosis?, JOURNAL OF NEUROINTERVENTIONAL SURGERY, Vol: 5, Pages: 94-96, ISSN: 1759-8478

Journal article

Lane TRA, Dharmarajah B, Kelleher D, Franklin IJ, Davies AHet 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

Journal article

Thapar A, Zheng Y, Dharmarajah B, Averkiou M, Shalhoub J, Davies AH, Leen ELSet al., 2012, Assessment of carotid plaque perfusion and ulceration with dynamic contrast enhanced ultrasound, INTERNATIONAL JOURNAL OF STROKE, Vol: 7, Pages: 60-60, ISSN: 1747-4930

Journal article

Kasivisvanathan V, Thapar A, Davies KJ, Dharmarajah B, Shalhoub J, Davies AHet al., 2012, Periprocedural outcomes after surgical revascularization and stenting for postradiotherapy carotid stenosis, Journal of Vascular Surgery, Vol: 56, Pages: 1143-1152.e2, ISSN: 0741-5214

Background: Treatment of head and neck malignancy commonly involves radiotherapy, which is associated with the development of carotid artery stenosis. There is little evidence to guide clinicians on how to intervene in significant postradiotherapy carotid stenosis. This systematic review collated data pertaining to perioperative outcomes of carotid artery surgery and carotid stenting in postradiotherapy carotid stenosis to aid the clinical decision-making process. Methods: A systematic review of the literature, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 guidelines, was performed. We screened 575 articles related to carotid artery surgery or stenting in postradiotherapy carotid stenosis, from which 21 studies were included for quantitative analysis. The primary outcome was stroke or death ≤30 days of the procedure. Secondary outcomes included cranial nerve injury, restenosis, stroke, and death at >30 days. Results: Nine publications recorded 211 surgical procedures in 179 patients. In symptomatic patients, the 30-day mortality rate was 2.6% and the stroke or death rate was 2.7%. In asymptomatic patients, the 30-day mortality rate was 0% and the stroke or death rate was 1.1%. Permanent cranial nerve palsy was experienced by 0.6% of patients. Twelve publications recorded 510 carotid artery stenting procedures in 482 patients. In symptomatic patients, the 30-day mortality rate was 5.1%, and the stroke or death rate was 5.1%. In asymptomatic patients, the 30-day mortality rate was 1.4%, and the stroke or death rate was 2.1%. There was no statistically significant difference in 30-day stroke or death rate between surgical revascularization and carotid artery stenting in all (odds ratio [OR], 0.54; 95% confidence interval [CI] 0.17-1.70; P =.43), symptomatic (OR, 0.52; 95% CI, 0.14-1.98; P =.38), or asymptomatic patients (OR, 0.55; 95% CI, 0.06-5.42; P =.99). Conclusions: The published outcomes from high-volume ce

Journal article

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