Imperial College London

Mr Daniel Richard Leff

Faculty of MedicineDepartment of Surgery & Cancer

Reader in Breast Surgery
 
 
 
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Contact

 

+44 (0)20 3312 1947d.leff

 
 
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Location

 

Queen Elizabeth the Queen Mother Wing (QEQM)St Mary's Campus

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Summary

 

Publications

Publication Type
Year
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137 results found

Muthuswamy K, Fisher R, Petrou F, Mavroveli S, Leff DRet al., 2019, Axillary lymph node dissection training in a post-Z0011 era: A survey of UK breast surgery trainees., Breast J

Journal article

Hadjiminas D, Leff D, Cunningham D, Thiruchelvam P, Hogben K, Al Mufti R, Vella J, Zacharioudakis K, Kontoulis T, Ramakrishnan R, Zhao Jet al., Can we see what is invisible? The role of MRI in the evaluation and management of patients with pathological nipple discharge, Breast Cancer Research and Treatment, ISSN: 0167-6806

Introduction: The aim of this study was to determine the ability of MRI to identify and assess the extent of disease in patients with pathological nipple discharge (PND) with an occult malignancy not evident on standard preoperative evaluation with mammography and ultrasound.Methods: Patients presenting to the breast unit of Imperial College Healthcare NHS Trust between December 2009 and December 2018 with PND and normal imaging were enrolled in the study. Pre-operative bilateral breast MRI was performed in all patients as part of our protocol and all patients were offered diagnostic microdochectomy. Results: A total of 82 patients fulfilled our selection criteria and were enrolled in our study. The presence of an intraductal papilloma (IDP) was identified as the cause of PND in 39 patients (48%), 15 patients had duct ectasia (DE-18%) and 4 patients had both an IDP and DE. Other benign causes were identified in 10 patients (12%). Despite normal mammography and ultrasound a malignancy was identified in 14 patients (17%). Eleven patients had DCIS (13.4%) , two had invasive lobular carcinoma and one patient had an invasive ductal carcinoma. The sensitivity of MRI in detecting an occult malignancy was 85.71% and the specificity was 98.53 %. The positive predictive value was 92.31% and the negative predictive value was 97.1%.Conclusions: Although a negative MRI does not exclude the presence of an occult malignancy the high sensitivity and specificity of this diagnostic modality can guide the surgeon and alter the management of patients with PND.

Journal article

Modi H, Singh H, Fiorentino F, Orihuela-Espina F, Athanasiou T, Yang G-Z, Darzi A, Leff Det al., Neural signatures of resident resilience, JAMA Surgery, ISSN: 2168-6254

Importance: Intraoperative stressors may compound cognitive load, prompting performance decline and threatening patient safety. However, not all surgeons cope equally well with stress, and the disparity between performance stability and decline under high cognitive demand may be characterized by differences in activation within brain areas associated with attention and concentration such as the prefrontal cortex (PFC).Objective: To compare PFC activation between surgeons demonstrating stable performance under temporal stress with those exhibiting stress-related performance decline. The a priori hypothesis being that under temporal demand sustained prefrontal “activation(s)” reflect performance stability, whereas performance decline is manifest as “deactivation(s)”.Design: Cohort study conducted from July 2015 to September 2016. Setting: Single center (Imperial College Healthcare NHS Trust, United Kingdom). Participants: 102 surgical residents (PGY1 and above) were invited to participate, of which 33 agreed to partake (median age [range]: 33 [29-56] years, 27 [82%] males).Exposure: Subjects performed a laparoscopic suturing task under two conditions: ‘self-paced’ (SP; without time per knot restrictions), and ‘time pressure’ (TP; two-minute per knot time restriction). Main Outcomes and Measures: A composite deterioration score was computed based on between-condition differences in task performance metrics [(task progression score (au), error score (mm), leak volume (ml) and knot tensile strength (N)]. Based on the composite score, quartiles were computed reflecting performance stability (Q1) and decline (Q4). Changes in PFC oxygenated haemoglobin concentration (HbO2) measured at 24 different locations using functional near-infrared spectroscopy were compared between Q1 and Q4. Secondary outcomes included subjective workload (Surgical Task Load Index) and heart rate. Results: Q1 residents demonstrated task-induced incr

Journal article

Berthelot M, Henry FP, Hunter J, Leff D, Wood S, Jallali N, Dex E, Ladislava L, Lo B, Yang GZet al., Pervasive wearable device for free tissue transfer monitoring based on advanced data analysis: clinical study report, Journal of Biomedical Optics, ISSN: 1083-3668

Free tissue transfer (FTT) surgery for breast reconstruction following mastectomy has become a routineoperation with high success rates. Although failure is low, it can have a devastating impact on patient recovery,prognosis and psychological well-being. Continuous and objective monitoring of tissue oxygen saturation (StO2) hasshown to reduce failure rates through rapid detection time of postoperative vascular complications. We have developeda pervasive wearable wireless device that employs near infrared spectroscopy (NIRS) to continuously monitor FTTviaStO2measurement. Previously tested on different models, this paper introduces the results of a clinical study. Thegoal of the study is to demonstrate the developed device can reliably detectStO2variations in a clinical setting: 14patients were recruited. Advanced data analysis were performed on theStO2variations, the relativeStO2gradientchange, and, the classification of theStO2within different clusters of blood occlusion level (from 0% to 100% at 25%step) based on previous studies made on a vascular phantom and animals. The outcomes of the clinical study concurwith previous experimental results and the expected biological responses. This suggests the device is able to correctlydetect perfusion changes and provide real-time assessment on the viability of the FTT in a clinical setting.

Journal article

Grant Y, Al-Khudairi R, St John E, Barschkett M, Cunningham D, Al-Mufti R, Hogben K, Thiruchelvam P, Hadjiminas DJ, Darzi A, Carter AW, Leff DRet al., 2019, Patient-level costs in margin re-excision for breast-conserving surgery, 19th Annual Meeting of the American-Society-of-Breast-Surgeons, Publisher: WILEY, Pages: 384-394, ISSN: 0007-1323

Conference paper

Chidambaram S, Erridge S, Leff D, Purkayastha Set al., 2019, A Randomized Controlled Trial of Skills Transfer: From Touch Surgery to Laparoscopic Cholecystectomy, JOURNAL OF SURGICAL RESEARCH, Vol: 234, Pages: 217-223, ISSN: 0022-4804

Journal article

Ashcroft J, Patel R, Singh H, Darzi A, Leff Det al., The Impact of Transcranial direct current stimulation (tDCS) on a surgical knot-tying task, Surgery and Cancer Research Afternoon Abstract

Conference paper

Modi H, Singh H, Yang G, Darzi A, Leff Det al., 2018, Neural correlates of stress resilience in the operating room, Journal of The American College of Surgeons, Vol: 227, Pages: e208-e208, ISSN: 1072-7515

IntroductionIntraoperative stressors can increase surgeons’ mental demands, precipitating technical performance decline and risking patient safety. However, the neural signatures of stress resilience among surgeons remain unknown. We aimed to compare activation in the prefrontal cortex (PFC)–important for attention and concentration–between residents demonstrating performance stability and those exhibiting performance decline when operating under time pressure.MethodsThirty-three surgical residents [median age (range) = 33 years (29 to 56), 27 males] performed a laparoscopic suturing task under ‘self-paced’ (no time restriction) and ‘time pressure’ (2-minute per knot time restriction) conditions. A composite deterioration score was calculated based on between-condition differences in technical performance, and subjects were divided into quartiles reflecting performance stability (Q1) and decline (Q4). Changes in oxygenated haemoglobin concentration (HbO2) measured at 24 prefrontal locations using functional near-infrared spectroscopy were compared between Q1 and Q4. Subjective workload was quantified using the Surgical Task Load Index (SURG-TLX).ResultsUnder time pressure, Q1 residents demonstrated task-induced increases in HbO2 in the bilateral ventrolateral PFC (VLPFC), whereas Q4 residents demonstrated HbO2 decreases. The amplitude of activation (ΔHbO2) was significantly greater in Q1 than Q4 in the bilateral VLPFC (left VLPFC: Q1=0.44±1.36μM, Q4=-0.03±1.83μM; right VLPFC: Q1=0.49±1.70μM, Q4=-0.32±2.00μM). There were no significant between-group differences in SURG-TLX scores.ConclusionsResilience to intraoperative stress is associated with sustained prefrontal activation indicating preserved attention and concentration. In contrast, sensitivity to stress is marked by prefrontal deactivation suggesting task disengagement. Future work will aim to develop interventions that recr

Journal article

Cutress RI, McIntosh SA, Potter S, Goyal A, Kirwan CC, Harvey J, Francis A, Carmichael AR, Vidya R, Vaidya JS, Fairbrother P, Benson JR, Reed MWR, Basu NN, Benson JR, Bundred NJ, Carmichael AR, Coombs N, Cutress RI, Dickson J, Dixon JM, Douek M, Fairbrother P, Francis A, Goyal A, Harcourt D, Harvey J, Holcombe C, Horsnell J, Iqbal FM, Khan LR, Kirwan CC, Leff DR, Maxwell AJ, McIntosh SA, Paraskeva N, Potter S, Rattay T, Reed MWR, Sami AS, Singer J, St John ER, Subramanian A, Tobias JS, Touqan N, Vaidya JS, Vidya R, Winters ZEet al., 2018, Opportunities and priorities for breast surgical research, The Lancet Oncology, Vol: 19, Pages: e521-e533, ISSN: 1470-2045

Journal article

Singh H, Modi H, Yang G, Darzi A, Leff Det al., 2018, Impact of escalating cognitive workload and temporal demands on surgeons cognitive function, 2nd International Neuroergonomics Conference, Publisher: Frontiers Media, ISSN: 1662-5161

Conference paper

Singh H, Modi H, Darzi A, Leff Det al., Robotic Surgery Improves Technical Performance and Enhances Prefrontal Activation During High Temporal Demand, Ara Darzi

Athanasiou Award Presentation

Conference paper

Osborne-Grinter M, Patel R, Modi H, Singh H, Darzi A, Leff Det al., Enhancing Surgical Performance Through Mental Rehearsal: An fNIRS Study, society of functional Near Infra-red Spectroscopy, Biennial meeting of society of functional Near Infra-red Spectroscopy (fNIRS-2018)

Background: Mental rehearsal (MR) is the cognitive rehearsal of a skill without movement to produce genuine sensory experiences. Mandates for new approaches to surgical skill acquisition have led to increased interest in MR as a method of practical learning supplementation. However, the neurophysiological mechanisms underpinning the psychomotor benefits of MR are poorly understood.Objective: To delineate the neural mechanisms that underpin mental imagery-related improvements in surgical performance.Methods: Twelve surgical trainees performed a laparoscopic suturing (LS) task (pre-intervention) followed by randomization to either MR (n=6) or textbook reading (TR; n=6). The LS task was repeated (post-intervention). Subjective workload was quantified using the Surgical Task Load Index and Spielberg State-Trait Anxiety Index. Mental imagery ability was assessed using a mental imagery questionnaire. Continuous heart rate (HR) monitoring captured stress responses. Cortical activation was recorded with optical neuroimaging (ETG-4000, Hitachi Medical Corp., Japan). Technical skill was assessed using progression scores (au), performance scores (units) and leak volumes (mL). Results: There were no baseline differences in demographics, mental imagery ability or laparoscopic performance between the two groups. MR significantly improved post-intervention performance scores (53.10 ± 28.00 a.u. vs. -61.32 ± 40.78 a.u., p=0.04) and reduced leak volume (3.48 ±0.44ml vs. 4.81 ± 0.61ml, p=0.04) when compared to TR. MR also led to significant improvement in subjective imagery ability (41.50 ± 4.59 a.u. vs 31.17 ± 9.11 a.u, P=0.009). There were no differences in subjective or objective stress measures between the two groups. Cortical activation was defined by a significant (p < 0.05) rise in oxygenated haemoglobin with a concurrent fall in deoxygenated haemoglobin. During MR, activation was demonstrated in the left supplementary motor area (S

Conference paper

Leff DR, de Silva T, Henry F, Thiruchelvam P, Hadjiminas D, Al-Mufti R, Hogben K, Hunter J, Wood S, Jalalli Net al., 2018, Streamlining decision making in contralateral risk-reducing mastectomy: impact of PREDICT and BOADICEA computations, Annals of Surgical Oncology, ISSN: 1068-9265

Introduction.Patients with sporadic breast cancer (BC)have low contralateral breast cancer risk (CLBCR;approximately 0.7% per annum) and contralateral pro-phylactic mastectomy (CPM) offers no survival advantage.CPM with autologous reconstruction (AR) has majormorbidity and resource implications.Objective.The aim of this study was to review the impactof PREDICT survival estimates and lifetime CLBCRscores on decision making for CPM in patients with uni-lateral BC.Methods.Ofn= 272 consecutive patients undergoingmastectomy and AR, 252 were included. Five- and 10-yearsurvival was computed with the PREDICT(V2) onlineprognostication tool, using age and clinicopathologicalfactors. Based on family history (FH) and tumor biology,CLBCR was calculated using validated BODICEA web-based software. Survival scores were correlated againstCLBCR estimates to identify patients receiving CPM with‘low’ CLBCR (\30% lifetime risk) and poor prognosis (5-year survival\80%). Patients with ‘high’ CLBCRreceiving unilateral mastectomy (UM) were similarlyidentified (UK National Institute of Health and CareExcellence [NICE] criteria for CPM,C30% lifetime BCrisk). Justifications motivating CPM were investigated.Results.Of 252 patients, 215 had UM and 37 had bilateralmastectomy and AR. Only 23 (62%) patients receivingCPM fulfilled the NICE criteria. Of 215 patients, 5 (2.3%)failed to undergo CPM despite high CLBCR and goodprognosis. CPMs were performed, at the patient’s request,for no clear justification (n= 8), contralateral non-invasivedisease, and/or FH (n= 5), FH alone (n= 4) and ipsilateralcancer recurrence-related anxiety (n= 3).Conclusion.In the absence of prospective risk estimatesof CLBCR and prognosis, certain patients receive CPMand reconstruction despite modest CLBCR, yet a propor-tion of patients with good prognoses and substantial riskare not undergoing CPM

Journal article

Leff DR, Patani N, Finn M, Eshleby S, Omar A, Kaur A, Contractor K, Thiruchelvam P, Curtis S, Main J, Cunningham D, Hogben K, AlMufti R, Hadjiminas DJet al., A ‘best practice’ care pathway improves management of mastitis and breast abscess, British Journal of Surgery, ISSN: 1365-2168

Background: As a result of surgical sub-specialisation, mastitis and breast abscess may be managed with unnecessary hospitalisation, prolonged admission, variable antibiotic prescribing, incision and drainage rather than aspiration, and loss to follow-up. Objective: To evaluate a ‘best-practice’ algorithm to improve management across a multi-site NHS Trust; focusing on uniformity of antibiotic prescribing, ultrasound assessment, admission rates, length of stay, intervention by aspiration or incision and drainage, and follow-up. Methods: Management was initially evaluated in a retrospective cohort (Phase-I: “PRE-pathway”, n=53) and subsequently compared to two prospective cohorts (Phase II and III = “POST-pathway”, n=141), one immediately following pathway introduction (Phase II n=61), and a further loop-closing audit (Phase-III, n=80) to assess sustainability of quality improvements. Results: The management pathway and referral proforma improved compliance with antibiotic guidelines (Pre=34.0% vs. Post=58.2%, p<0.01), which was maintained (Phase-II=54.1% vs. III=61.3%, p=0.68) and sustainably increased ultrasound assessment (Pre=37.7% vs. Post=77.3%, p<0.001; Phase-II=75.4% vs. III=78.8%, p=0.89). Reductions in rates of incision and drainage (Pre=7.5% vs. Post=0.7%, p<0.01) were maintained (Phase-II=0% vs. III=1.3%, p=0.38), and follow-up consistently improved (Pre=43.4% vs. Post=95.7%, p<0.001; Phase-II=91.8% vs. III=98.8%, p=0.12). Reduced hospital admission (Pre=30.2% vs. Post=20.6%, p=0.25) and median length of stay [Pre=2 days (range=1-5) vs. Post=1 day (range=1-6), p=0.07] were not statistically significant.

Journal article

Singh H, Modi HN, Ranjan S, Dilley J, Airantzis D, Yang G, Darzi A, Leff Det al., 2018, Robotic surgery improves technical performance and enhances prefrontal activation during high temporal demand, Annals of Biomedical Engineering, ISSN: 0090-6964

Robotic surgery may improve technical performance and reduce mental demands compared to laparoscopic surgery. However, no studies have directly compared the impact of robotic and laparoscopic techniques on surgeons’ brain function. This study aimed to assess the effect of the operative platform (robotic surgery or conventional laparoscopy) on prefrontal cortical activation during a suturing task performed under temporal demand. Eight surgeons (mean age ± SD = 34.5 ± 2.9 years, male:female ratio = 7:1) performed an intracorporeal suturing task in a self-paced manner and under a 2 min time restriction using conventional laparoscopic and robotic techniques. Prefrontal activation was assessed using near-infrared spectroscopy, subjective workload was captured using SURG-TLX questionnaires, and a continuous heart rate monitor measured systemic stress responses. Task progression scores (au), error scores (au), leak volumes (mL) and knot tensile strengths (N) provided objective assessment of technical performance. Under time pressure, robotic suturing led to improved technical performance (median task progression score: laparoscopic suturing = 4.5 vs. robotic suturing = 5.0; z = − 2.107, p = 0.035; median error score: laparoscopic suturing = 3.0 mm vs. robotic suturing = 2.1 mm; z = − 2.488, p = 0.013). Compared to laparoscopic suturing, greater prefrontal activation was identified in seven channels located primarily in lateral prefrontal regions. These results suggest that robotic surgery improves performance during high workload conditions and is associated with enhanced activation in regions of attention, concentration and task engagement.

Journal article

Fisher R, Muthuswamy K, Petrou F, Mavroveli S, Thiruchelvam P, Fisher C, Leff Det al., 2018, The impact of the American College of Surgeons Oncology Group Z0011 Trial on axillary lymph node dissection cases worldwide: A systematic review, 19th Annual Meeting of the American-Society-of-Breast-Surgeons, Publisher: SPRINGER, Pages: 434-434, ISSN: 1068-9265

Conference paper

Muthuswamy K, Fisher R, Petrou F, Mavroveli S, Leff Det al., 2018, Specialist trainee experiences in axillary lymph node dissection in a post-Z11-era survey indicates declining exposure and confidence, 19th Annual Meeting of the American-Society-of-Breast-Surgeons, Publisher: SPRINGER, Pages: 393-394, ISSN: 1068-9265

Conference paper

Deligianni F, Singh H, Modi H, Darzi A, Leff D, Yang GUANGet al., Expertise Related Disparity in Prefrontal-Motor Brain Connectivity, Hamlyn Symposium on Medical Robotics

Conference paper

Thiruchelvam P, Fisher C, Leff DR, Domcheck Set al., 2018, Pervasive genetic testing, Lancet, Vol: 391, Pages: 2089-2091, ISSN: 0140-6736

Journal article

Erridge S, Chidambaram S, Leff DR, Purkayastha Set al., 2018, VALIDATING TOUCH SURGERY FOR TRAINING IN LAPAROSCOPIC CHOLECYSTECTOMIES: A RANDOMISED CONTROLLED TRIAL, Annual Meeting of the Society-of-Academic-and-Research-Surgery (SARS), Publisher: WILEY, Pages: 30-30, ISSN: 0007-1323

Conference paper

Modi HN, Singh H, Yang G, Darzi A, Leff DRet al., Robotic surgery improves attention and concentration during times of intraoperative temporal stress, Association of Surgeons of Great Britain & Ireland International Surgical Congress, Publisher: Wiley, ISSN: 1365-2168

Conference paper

Leiloglou M, Qi J, Rees Whippey D, Curtis A, Price C, Copner N, Martin-Gonzalez P, Hanna G, Darzi A, Leff D, Elson Det al., Guiding Fluorescence-Augmented Imaging System for Breast Cancer Surgery, BMES Annual Meeting

Conference paper

Leiloglou M, Qi J, Rees Whippey D, Curtis A, Price C, Copner N, Martin-Gonzalez P, Hanna G, Darzi A, Leff D, Elson Det al., Guiding Fluorescence-Augmented Imaging System for Breast Cancer Surgery, EPSRC Image Guided Therapies Young Investigators

Conference paper

Stebbing J, Baranau Y, Manikhas A, Lee SJ, Thiruchelvam P, Leff D, Esteva FJet al., 2018, Total pathological complete response versus breast pathological complete response in clinical trials of reference and biosimilar trastuzumab in the neoadjuvant treatment of breast cancer, EXPERT REVIEW OF ANTICANCER THERAPY, Vol: 18, Pages: 531-541, ISSN: 1473-7140

Journal article

Modi HN, Singh H, Yang G, Darzi A, Leff Det al., 2017, A decade of imaging surgeons' brain function (Part II): a systematic review of applications for technical and non-technical skills assessment, Surgery, Vol: 162, Pages: 1130-1139, ISSN: 1532-7361

Background: Functional neuroimaging technologies enable assessment of operator brain function, and can deepen our understanding of skills learning, ergonomic optima and cognitive processes in surgeons. Whilst there has been a critical mass of data detailing surgeons’ brain function, this literature has not been systematically reviewed.Methods: A systematic search of original neuroimaging studies assessing surgeons’ brain function, and published up until November 2016, was conducted using Medline, Embase and PsycINFO databases.Results: Twenty-seven studies fulfilled the inclusion criteria, including three feasibility studies, fourteen studies exploring the neural correlates of technical skill acquisition, and the remainder investigating brain function in the context of intraoperative decision-making (n=1), neurofeedback training (n=1), robot-assisted technology (n=5), and surgical teaching (n=3). Early stages of learning open surgical tasks (knot-tying) are characterised by prefrontal cortical (PFC) activation which subsequently attenuates with deliberate practice. However, with complex laparoscopic skills (intra-corporeal suturing), PFC engagement requires substantial training and attenuation occurs over a longer time-course, following years of refinement. Neurofeedback and interventions that improve neural efficiency may enhance technical performance and skills learning. Conclusions: Imaging surgeons’ brain function has identified neural signatures of expertise which might help inform objective assessment and selection processes. Interventions which improve neural efficiency may target skill-specific brain regions and augment surgical performance.

Journal article

Modi HN, Singh H, Yang G, Darzi A, Leff Det al., 2017, Neural markers of sensitivity to intraoperative temporal stress in surgeons, Mexican Symposium on NIRS Neuroimaging, Publisher: MEXNIRS

Conference paper

Orihuela-Espina F, Leff DR, James DRC, Darzi AW, Yang G-Zet al., 2017, Imperial College near infrared spectroscopy neuroimaging analysis framework., Neurophotonics, Vol: 5, ISSN: 2329-4248

This paper describes the Imperial College near infrared spectroscopy neuroimaging analysis (ICNNA) software tool for functional near infrared spectroscopy neuroimaging data. ICNNA is a MATLAB-based object-oriented framework encompassing an application programming interface and a graphical user interface. ICNNA incorporates reconstruction based on the modified Beer-Lambert law and basic processing and data validation capabilities. Emphasis is placed on the full experiment rather than individual neuroimages as the central element of analysis. The software offers three types of analyses including classical statistical methods based on comparison of changes in relative concentrations of hemoglobin between the task and baseline periods, graph theory-based metrics of connectivity and, distinctively, an analysis approach based on manifold embedding. This paper presents the different capabilities of ICNNA in its current version.

Journal article

Ranjan S, Modi HN, Singh H, Darzi A, Leff Det al., 2017, The impact of 3D vision on prefrontal activation and technical performance during a robotic suturing task, 11th London Surgical Symposium

Conference paper

Ranjan S, Modi HN, Singh H, Darzi A, Leff Det al., 2017, The impact of time pressure on prefrontal cortical activation and technical performance during robotic suturing, 11th London Surgical Symposium

Conference paper

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