Imperial College London

Mr Daniel Richard Leff

Faculty of MedicineDepartment of Surgery & Cancer

Reader in Breast Surgery
 
 
 
//

Contact

 

+44 (0)20 3312 1947d.leff

 
 
//

Location

 

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

//

Summary

 

Publications

Publication Type
Year
to

167 results found

Kedrzycki MS, Elson DS, Leff DR, 2020, ASO Author Reflections: Fluorescence-Guided Sentinel Node Biopsy for Breast Cancer., Ann Surg Oncol

Journal article

Jiwa N, Gandhewar R, Chauhan H, Ashrafian H, Kumar S, Wright C, Takats Z, Leff DRet al., 2020, Diagnostic Accuracy of Nipple Aspirate Fluid Cytology in Asymptomatic Patients: A Meta-analysis and Systematic Review of the Literature., Ann Surg Oncol

PURPOSE: To calculate the diagnostic accuracy of nipple aspirate fluid (NAF) cytology. BACKGROUND: Evaluation of NAF cytology in asymptomatic patients conceptually offers a non-invasive method for either screening for breast cancer or else predicting or stratifying future cancer risk. METHODS: Studies were identified by performing electronic searches up to August 2019. A meta-analysis was conducted to attain an overall pooled sensitivity and specificity of NAF for breast cancer detection. RESULTS: A search through 938 studies yielded a total of 19 studies. Overall, 9308 patients were examined, with cytology results from 10,147 breasts [age (years), mean ± SD = 49.73 ± 4.09 years]. Diagnostic accuracy meta-analysis of NAF revealed a pooled specificity of 0.97 (95% CI 0.97-0.98), and sensitivity of 0.64 (95% CI 0.62-0.66). CONCLUSIONS: The diagnostic accuracy of nipple smear cytology is limited by poor sensitivity. If nipple fluid assessment is to be used for diagnosis, then emerging technologies for fluid biomarker analysis must supersede the current diagnostic accuracy of NAF cytology.

Journal article

Kedrzycki MS, Leiloglou M, Ashrafian H, Jiwa N, Thiruchelvam PTR, Elson DS, Leff DRet al., 2020, Meta-analysis comparing fluorescence imaging with radioisotope and blue dye-guided sentinel node identification for breast cancer surgery., Annals of Surgical Oncology, ISSN: 1068-9265

INTRODUCTION: Conventional methods for axillary sentinel lymph node biopsy (SLNB) are fraught with complications such as allergic reactions, skin tattooing, radiation, and limitations on infrastructure. A novel technique has been developed for lymphatic mapping utilizing fluorescence imaging. This meta-analysis aims to compare the gold standard blue dye and radioisotope (BD-RI) technique with fluorescence-guided SLNB using indocyanine green (ICG). METHODS: This study was registered with PROSPERO (CRD42019129224). The MEDLINE, EMBASE, Scopus, and Web of Science databases were searched using the Medical Subject Heading (MESH) terms 'Surgery' AND 'Lymph node' AND 'Near infrared fluorescence' AND 'Indocyanine green'. Studies containing raw data on the sentinel node identification rate in breast cancer surgery were included. A heterogeneity test (using Cochran's Q) determined the use of fixed- or random-effects models for pooled odds ratios (OR). RESULTS: Overall, 1748 studies were screened, of which 10 met the inclusion criteria for meta-analysis. ICG was equivalent to radioisotope (RI) at sentinel node identification (OR 2.58, 95% confidence interval [CI] 0.35-19.08, p < 0.05) but superior to blue dye (BD) (OR 9.07, 95% CI 6.73-12.23, p < 0.05). Furthermore, ICG was superior to the gold standard BD-RI technique (OR 4.22, 95% CI 2.17-8.20, p < 0.001). CONCLUSION: Fluorescence imaging for axillary sentinel node identification with ICG is equivalent to the single technique using RI, and superior to the dual technique (RI-BD) and single technique with BD. Hospitals using RI and/or BD could consider changing their practice to ICG given the comparable efficacy and improved safety profile, as well as the lesser burden on hospital infrastructure.

Journal article

Ashcroft J, Patel R, Woods A, Darzi A, Singh H, Leff Det al., 2020, Prefrontal Transcranial Direct-Current Stimulation Improves Early Technical Skills in Surgery, Brain Stimulation, ISSN: 1876-4754

Journal article

Scrimgeour GE, St John ER, Leff DR, 2020, Langer's arch: A rare but important consideration for axillary surgery with implications for training., Breast J

Langer's arch (LA), although rare, is an important anatomical anomaly in the axilla that may be encountered during axillary lymph node dissection (ALND). Failure to recognize this anomaly may cause disorientation during ALND, resulting in inadequate clearance, with implications for local disease recurrence and inaccurate staging. Here, we present a case that highlights the confusion LA can cause even in experienced surgeons. With indications for ALND decreasing, resulting in lower operative numbers, surgeons are less likely to be exposed to this structure during their training. Improving knowledge and understanding of LA is important to ensure breast surgeons' preparedness for axillary surgery.

Journal article

Modi H, Singh H, Darzi A, Leff Det al., 2020, Multitasking and time pressure in the operating room: impact on surgeons’ brain function, Annals of Surgery, Vol: 272, Pages: 648-657, ISSN: 0003-4932

Objective:To assess the impact of multitasking and time pressure on surgeons’ brain function during laparoscopic suturing.Summary Background Data:Recent neuroimaging evidencesuggests that deterioration in surgical performance under time pressure is associated with deactivationof the prefrontal cortex (PFC),an area important for executive functions. However, the effect ofmultitasking on operator brain functionremains unknown.Methods:29surgical residentsperformed anintracorporealsuturing task under fourconditions: 1) self-pacedsuturing,2) time-pressured suturing, 3) self-paced suturingplus decision-making, and 4) time-pressured suturing plus decision-making. Subjectiveworkload was quantified using the Surgical Task Load Index. Technical skill was objectively assessed using task progression scores, error scores, leak volumes, and knot tensile strengths. PFC activation was measuredusing optical neuroimaging. Results:Compared with self-paced suturing, subjective workload(au)was significantly greater in time-pressuredsuturing (146.0 vs. 196.0), suturing with decision-making (146.0 vs.182.0), and time-pressuredsuturing with decision-making (146.0 vs.227.0). Technical performance duringcombined suturing and decision-making taskswas inferiortosuturing alone undertime pressure orself-paced conditions(p<0.001).Significant dorsolateral PFC (DLPFC) activations were observed during self-paced suturing, and ventrolateral PFC (VLPFC) deactivations were identified during time-pressuredsuturing. However, suturing in conjunction withdecision-making resulted in 2significantdeactivation across boththe VLPFC and DLPFC (p<0.05). Random effects regression analysis confirmed decision-making predicts VLPFC and DLPFC deactivation (z=-2.62, p<0.05).Conclusions:Performance degradation during high workload conditions is associated with deactivation of prefrontal regions important fo

Journal article

Dawidziuk A, Patel R, Darzi A, Leff D, Singh Het al., 2020, The Impact of tDCS on fNIRS Haemodynamic Responses During a Surgical Task: A Pilot Study, London Surgical Symposium 2020

Conference paper

Dawidziuk A, Patel R, Darzi A, Leff D, Singh Het al., 2020, Using Optical Neuroimaging to Reveal Mechanisms of Augmentation by Transcranial Electrical Stimulation (TES): A Systematic Review, Brainbox Initiative Virtual Conference 2020

Conference paper

Jallali N, Hunter JE, Henry FP, Wood SH, Hogben K, Almufti R, Hadjiminas D, Dunne J, Thiruchelvam PTR, Leff DRet al., 2020, The feasibility and safety of immediate breast reconstruction in the COVID-19 era, Journal of Plastic, Reconstructive and Aesthetic Surgery, ISSN: 0007-1226

The coronavirus disease-2019 pandemic has had a significant impact on the delivery of surgical services, particularly reconstructive surgery. This article examines the current evidence to assess the feasibility of recommencing immediate breast reconstruction services during the pandemic and highlights considerations required to ensure patient safety.

Journal article

Joshi M, Karat I, Leff DR, 2020, COVID19 and breast surgery - silver linings?, BRITISH JOURNAL OF SURGERY, Vol: 107, Pages: E359-E359, ISSN: 0007-1323

Journal article

Kassanos P, Berthelot M, Kim JA, Rosa BMG, Seichepine F, Anastasova S, Sodergren MH, Leff DR, Lo B, Darzi A, Yang G-Zet al., 2020, Smart sensing for surgery from tethered devices to wearables and implantables, IEEE Systems Man and Cybernetics Magazine, Vol: 6, Pages: 39-48, ISSN: 2333-942X

Recent developments in wearable electronics have fueled research into new materials, sensors, and microelectronic technologies for the realization of devices that have increased functionality and performance. This is further enhanced by advances in fabr ication methods and printing techniques, stimulating research on implantables and the advancement of existing medical devices. This article provides an overview of new designs, embodiments, fabrication methods, instrumentation, and informatics as well as the challenges in developing and deploying such devices and clinical applications that can benefit from them. The need for and use of these technologies across the perioperative surgical-care pathway are highlighted, along with a vision for the future and how these tools can be adopted by potential end users and health-care systems.

Journal article

Muthuswamy K, Fisher R, Mavroveli S, Petrou F, Khawar S, Amlani A, Hanna GB, Hadjiminas D, Thiruchelvam P, Leff Det al., 2020, Assessment of technical skills in axillary lymph node dissection, Annals of Surgery, ISSN: 0003-4932

Objective A simulator to enable safe practice and assessment of ALND has been designed, and face, content and construct validity has been investigated.Summary and Background Data The reduction in the number of ALNDs conducted has led to decreased resident exposure and confidence. MethodsA cross-sectional multi-center observational study was carried out between July 2017 to August 2018. Following model development, 30 surgeons ofvarying experience (n=9 ‘experts’, n=11 ‘senior residents’ and n=10 ‘junior residents’) were asked to perform a simulated ALND. Face and content validity questionnaires were administered immediately after ALND. All ALND procedures were retrospectively assessed by two attending breast surgeons, blinded to operator identity, using a video-based assessment tool and an end product assessment tool.ResultsStatistically significant differences between groups were observed across all operative sub-phases on theaxillary clearance assessment tool (p<0.001). Significant differences between groups were observed for overall procedure quality (p<0.05) and total number of lymph nodes harvested (p<0.001). However, operator grade could not be distinguished across other end product variables such as axillary vein damage (p=0.864) and long thoracic nerve injury R1 ALND Structured abstract(p=0.094). Overall, participants indicated that the simulator has good anatomical (median score >7) and procedural realism (median score >7).ConclusionsVideo based analysis demonstrates construct validity for ALND assessment. Given reduced ALND exposure, this simulation is a useful adjunct for both technical skills training and formative Deanery orFaculty administered assessments.

Journal article

Gandhewar R, Jiwa N, Leff D, 2020, How Are We Preparing Our Nipple Smears for Cytology?, International Surgical Conference of the Association-of-Surgeons-in-Training, Publisher: WILEY, Pages: 8-8, ISSN: 0007-1323

Conference paper

Denning M, Hayes P, Tsang F, Leff D, Thiruchelvam P, Hadjiminas Det al., 2020, The modified crescenteric anterior intercostal perforator (AICAP) flap, Plastic and Reconstructive Surgery Global Open, Vol: 8, ISSN: 2169-7574

Background Lower pole breast cancers are challenging to manage since conventional wide local excision may produce a “bird beak” deformity. In an era of oncoplastic surgery, techniques that balance oncological results with cosmetic outcomes such as local flaps have extended the role of breast conserving surgery. Local flaps are particularly useful for partial breast reconstruction due to the relative simplicity of the surgical procedure, and reduced morbidity. Intercostal artery perforator (ICAP) flaps have a shorter duration of surgery than free flaps and do not require microsurgical anastomoses. AICAP flaps provide excellent cosmesis, yet traditional crescenteric harvest yields limited volume for reconstruction.Idea/InnovationWe describe a modification to an established reconstructive technique for lower pole breast defects. The technique is based on 3 extensions of tissue, providing a larger volume of tissue replacement compared with traditional AICAP flaps. The technique is particularly suitable for small and medium sized non-ptotic breasts, with lower pole tumours. ConclusionThe modified crescenteric AICAP technique can be used to increase the available tissue when performing lower pole reconstructions.

Journal article

Patel R, Ashcroft J, Darzi A, Singh H, Leff Det al., 2020, Neuroenhancement in surgeons: Benefits, risks and ethical dilemmas, British Journal of Surgery, Vol: 107, Pages: 946-950, ISSN: 0007-1323

Mistakes are inevitable in healthcare and surgeons traditionally aim to avoid these through training and surgical technology. Emerging neuroenhancement techniques have demonstrated significant gains in cognitive and motor domains, which could offset the errors seen in surgical practice. We discuss neurostimulation as a neuro-enhancing tool for surgeons and the surrounding ethical issues of its application in healthcare.

Journal article

Patel R, Dawidziuk A, Darzi A, Singh H, Leff DRet al., 2020, Systematic review of combined functional near-infrared spectroscopy and transcranial direct-current stimulation studies., Neurophotonics, Vol: 7, ISSN: 2329-423X

Significance: Combining transcranial direct-current stimulation (tDCS) with functional near-infrared spectroscopy (fNIRS) is a recent approach to exploring brain activation evoked by neurostimulation. Aim: To critically evaluate studies combining tDCS and fNIRS and provide a consolidated overview of cortical hemodynamic responses to neurostimulation. Approach: Key terms were searched in three databases (MEDLINE, EMBASE, and PsycINFO) with cross-referencing and works from Google Scholar also evaluated. All studies reporting on fNIRS-derived hemoglobin changes evoked by tDCS were included. Results: Literature searches revealed 474 articles, of which 28 were included for final review (22 in healthy individuals: 9 involving rest and 13 with tasks; 6 in the clinical setting). At rest, an overall increase in cortical activation was observed in fNIRS responses at the site of stimulation, with evidence suggesting nonstimulated brain regions are also similarly affected. Conversely, during tasks, reduced cortical activation was observed during online stimulation. Offline and poststimulation effects were less consistent, as is the impact on clinical populations and their symptom correlation. Conclusion: This review explores the methodological frameworks for fNIRS-tDCS evaluations and summarizes hemodynamic responses associated with tDCS in all populations. Our findings provide further evidence of the impact of tDCS on neuronal activation within functionally connected networks.

Journal article

Dryden S, Anastasova S, Satta G, Thompson AJ, Leff DR, Darzi AWet al., 2020, Toward point-of-care uropathogen detection using SERS active filters, Optical Diagnostics and Sensing XX: Toward Point-of-Care Diagnostics, Publisher: SPIE, Pages: 1124705-1-1124705-7

150 million people worldwide suffer one or more urinary tract infections (UTIs) annually. UTIs are a significant health burden: societal costs of UTI exceed $3.5 billion in the U.S. alone; 5% of sepsis cases arise from a urinary source; and UTIs are a prominent contributor toward antimicrobial resistance (AMR). Current diagnostic frameworks exacerbate this burden by providing inaccurate and delayed diagnosis. Rapid point-of-care bacterial identification will allow for early precision treatment, fundamentally altering the UTI paradigm. Raman spectroscopy has a proven ability to provide rapid bacterial identification but is limited by weak bacterial signal and a susceptibility to background fluorescence. These limitations may be overcome using surface enhanced Raman spectroscopy (SERS), provided close and consistent application of bacteria to the SERS-active surface can be achieved. Physical filtration provides a means of capturing uropathogens, separating them from the background solution and acting as SERS-active surface. This work demonstrates that filters can provide a means of aggregating bacteria, thereby allowing subsequent enhancement of the acquired Raman signal using metallic nanoparticles. 60 bacterial suspensions of common uropathogens were vacuum filtered onto commercial polyvinylidene fluoride membrane filters and Raman signals were enhanced by the addition of silver nanoparticles directly onto the filter surface. SERS spectra were acquired using a commercial Raman spectrometer (Ocean Optics, Inc.). Principal Component – Linear Discriminant Analysis provided discrimination of infected from control samples (accuracy: 88.75%, 95% CI: 79.22-94.59%, p-value <0.05). Amongst infected samples uropathogens were classified with 80% accuracy. This study has demonstrated that combining Raman spectroscopy with membrane filtration and SERS can provide identification of infected samples and rapid bacterial classification.

Conference paper

Leiloglou M, Gkouzionis I, Avila-Rencoret FB, Chalau V, Kedrzycki M, Darzi A, Leff DR, Elson DSet al., 2020, Snapshot hyperspectral system for breast conserving surgery guidance

© OSA 2020 © 2020 The Author(s) There is an unmet need for accurate tumour localization in vivo during breast conserving surgery. Herein a novel snapshot hyperspectral system is presented for accurately detecting the intrinsic fluorescence signal in real-time fluorescence guided surgery.

Conference paper

Courtney A, O'Connell R, Rattay T, Kim B, Cutress RI, Kirwan CC, Gandhi A, Fairbrother P, Sharma N, Cartlidge CWJ, Horgan K, McIntosh SA, Leff DR, Vidya R, Potter S, Holcombe C, Copson E, Coles CE, Dave RVet al., 2020, The B-MaP-C study: Breast cancer management pathways during the COVID-19 pandemic. Study protocol., Int J Surg Protoc, Vol: 24, Pages: 1-5

Introduction: Approximately 55,000 women in the United Kingdom are diagnosed with new breast cancer annually. Since emerging in December 2019, SARS-CoV-2 (coronavirus disease 2019, COVID-19) has become a global pandemic, affecting healthcare delivery worldwide. In response to the pandemic, multiple guidelines were issued to assist with rationalising breast cancer care. The primary aim of the B-MaP-C study is to audit and describe breast cancer management of patients newly diagnosed with breast cancer during the COVID-19 pandemic against pre-COVID-19 management practice in the UK. The implications of changes to management will be determined and the impact of a COVID-19 diagnosis on the patient's breast cancer management will be determined. Methods and analysis: This is a multi-centre collaborative audit of consecutive breast cancer patients undergoing treatment decisions during the acute and recovery phases of the COVID-19 pandemic. All patients with newly diagnosed primary breast cancer, whose treatment was decided in a multidisciplinary meeting from the 16th March 2020, are eligible for inclusion. Ethics and dissemination: As this is an audit ethical approval is not required. Each participating centre is required to register the study locally and obtain local governance approvals prior to commencement of data collection. Local audit data will be available to individual participating units for governance purposes. The results of the data analysis will be submitted for publication, as well as disseminated via the ABS newsletter and a webinar. All data will be presented at national and international conferences, circumstances permitting. Registration details: Each participating centre received local governance audit registration.

Journal article

Patel R, Ashcroft J, Patel A, Ashrafian H, Woods A, Singh H, Darzi A, Leff Det al., 2019, The impact of transcranial direct current stimulation on upper-limb motor performance in healthy adults: A systematic review and meta-analysis, Frontiers in Neuroscience, Vol: 13, ISSN: 1662-453X

Background: Transcranial direct current stimulation (tDCS) has previously been reported to improve facets of upper limb motor performance such as accuracy and strength. However, the magnitude of motor performance improvement has not been reviewed by contemporaneous systematic review or meta-analysis of sham vs. active tDCS.Objective: To systematically review and meta-analyse the existing evidence regarding the benefits of tDCS on upper limb motor performance in healthy adults.Methods: A systematic search was conducted to obtain relevant articles from three databases (MEDLINE, EMBASE, and PsycINFO) yielding 3,200 abstracts. Following independent assessment by two reviewers, a total of 86 articles were included for review, of which 37 were deemed suitable for meta-analysis.Results: Meta-analyses were performed for four outcome measures, namely: reaction time (RT), execution time (ET), time to task failure (TTF), and force. Further qualitative review was performed for accuracy and error. Statistically significant improvements in RT (effect size −0.01; 95% CI −0.02 to 0.001, p = 0.03) and ET (effect size −0.03; 95% CI −0.05 to −0.01, p = 0.017) were demonstrated compared to sham. In exercise tasks, increased force (effect size 0.10; 95% CI 0.08 to 0.13, p < 0.001) and a trend towards improved TTF was also observed.Conclusions: This meta-analysis provides evidence attesting to the impact of tDCS on upper limb motor performance in healthy adults. Improved performance is demonstrable in reaction time, task completion time, elbow flexion tasks and accuracy. Considerable heterogeneity exists amongst the literature, further confirming the need for a standardised approach to reporting tDCS studies.

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., 2019, 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, Vol: 178, Pages: 115-120, 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

Berthelot M, Ashcroft J, Boshier P, Henry FP, Hunter J, Lo B, Yang G-Z, Leff Det al., 2019, Use of near infrared spectroscopy and implantable Doppler for postoperative monitoring of free tissue transfer for breast reconstruction: a systematic review and meta-analysis, Plastic and Reconstructive Surgery Global Open, Vol: 7, Pages: 1-8, ISSN: 2169-7574

Background: Failure to accurately assess the perfusion of free tissue transfer (FTT) in the early postoperative periodmay contribute to failure, which is a source of major patient morbidity and healthcare costs.Goal: This systematic review and meta-analysis aims to evaluate and appraise current evidence for the use of nearinfrared spectroscopy (NIRS) and/or implantable Doppler (ID) devices compared with conventional clinicalassessment (CCA) for postoperative monitoring of FTT in reconstructive breast surgery.Methods: A systematic literature search was performed in accordance with the PRISMA guidelines. Studies in humansubjects published within the last decade relevant to the review question were identified. Meta-analysis using randomeffects models of FTT failure rate and STARD scoring were then performed on the retrieved publications.Results: 19 studies met the inclusions criteria. For NIRS and ID, the mean sensitivity for the detection of FTT failure is99.36% and 100% respectively, with average specificity of 99.36% and 97.63% respectively. From studies withsufficient reported data, meta-analysis results demonstrated that both NIRS (OR = 0.09 [0.02, 0.36], P < 0.001) and ID(OR = 0.39 [0.27, 0.95], P = 0.04) were associated with significant reduction of FTT failure rates compared to CCA.Conclusion: The use of ID and NIRS provide equivalent outcomes in detecting FTT failure and were superior to CCA.The ability to acquire continuous objective physiological data regarding tissue perfusion is a perceived advantage ofthese techniques. Reduced clinical staff workload and minimised hospital costs are also perceived as positiveconsequences of their use.

Journal article

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, The Breast Journal, Vol: 25, Pages: 1037-1041, ISSN: 1075-122X

Journal article

Modi HN, Singh H, Fiorentino F, Orihuela-Espina F, Athanasiou T, Yang G-Z, Darzi A, Leff DRet al., 2019, Association of residents' neural signatures with stress resilience during surgery, JAMA Surgery, Vol: 154, 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. Design, Setting, and Participants: Cohort study conducted from July 2015 to September 2016 at the Imperial College Healthcare National Health Service Trust, England. One hundred two surgical residents (postgraduate year 1 and greater) were invited to participate, of which 33 agreed to partake. Exposures: Participants performed a laparoscopic suturing task under 2 conditions: self-paced (SP; without time-per-knot restrictions), and time pressure (TP; 2-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 [arbitrary units], error score [millimeters], leak volume [milliliters], and knot tensile strength [newtons]). Based on the composite score, quartiles were computed reflecting performance stability (quartile 1 [Q1]) and decline (quartile 4 [Q4]). Changes in PFC oxygenated hemoglobin 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: Of the 33 participants, the median age was 33 years, the range was 29 to 56 years, and 27 were men (82%). The Q1 residents demonstrated task-induced increases in HbO2 across the bilateral ventrolateral PFC (VLPFC) and right dorsolateral P

Journal article

Berthelot M, Henry FP, Hunter J, Leff D, Wood S, Jallali N, Dex E, Ladislava L, Lo B, Yang GZet al., 2019, Pervasive wearable device for free tissue transfer monitoring based on advanced data analysis: clinical study report, Journal of Biomedical Optics, Vol: 24, Pages: 067001-1-067001-8, 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

Modi H, Singh H, Fiorentino F, Orihuela-Espina F, Athanasiou T, Yang G-Z, Darzi A, Leff Det al., 2019, 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

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, British Journal of Surgery, Vol: 106, Pages: 384-394, ISSN: 1365-2168

BackgroundHigh rates of reoperation following breast‐conserving surgery (BCS) for positive margins are associated with costs to healthcare providers. The aim was to assess the quality of evidence on reported re‐excision costs and compare the direct patient‐level costs between patients undergoing successful BCS versus reoperations after BCS.MethodsThe study used data from women who had BCS with or without reoperation at a single institution between April 2015 and March 2016. A systematic review of health economic analysis in BCS was conducted and scored using the Quality of Health Economic Studies (QHES) instrument. Financial data were retrieved using the Patient‐Level Information and Costing Systems (PLICS) for patients. Exchange rates used were: US $1 = £0·75, £1 = €1·14 and US $1 = €0·85.ResultsThe median QHES score was 47 (i.q.r. 32·5–79). Only two of nine studies scored in the upper QHES quartile (score at least 75). Costs of initial lumpectomy and reoperation were in the range US $1234–11786 and $655–9136 respectively. Over a 12‐month interval, 153 patients had definitive BCS and 59 patients underwent reoperation. The median cost of reoperations after BCS (59 patients) was £4511 (range 1752–18 019), representing an additional £2136 per patient compared with BCS without reoperation (P < 0·001).ConclusionThe systematic review demonstrated variation in methodological approach to cost estimates and a paucity of high‐quality cost estimate studies for reoperations. Extrapolating local PLICS data to a national level suggests that getting BCS right first time could result in substantial savings.

Journal article

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

BackgroundSurgical training has traditionally involved teaching trainees in the operating room. However, intraoperative training is time-intensive and exposes patients to greater risks. Touch Surgery (TS) is an application that uses animation to provide simulation training via cognitive task analysis as an adjunct to intraoperative training.MethodsForty students were recruited and randomly allocated to either a control or intervention group. Each group received the same preparation before intervention, including a 10-min introduction to laparoscopic equipment and a 15-min educational tutorial on laparoscopic cholecystectomies. The participants then received training via either TS (intervention) or written information (control). Their performance was compared using a validated scoring tool on a porcine laparoscopic cholecystectomy model. Significance was defined as P < 0.050.ResultsIn total, n = 22 and n = 18 participants were randomly assigned to intervention and control groups, respectively. There was no significant difference between age (P = 0.320), year of medical school (P = 0.322), handedness (P = 1.000), or gender (P = 0.360) of the groups. The overall mean performance score was higher for intervention (mean ± SD = 41.9 ± 22.5) than control (mean ± SD = 24.7 ± 19.6; P = 0.016). There was no significant difference between scores for each intraoperative segment between the intervention and control group (P > 0.050).ConclusionsThis study demonstrates that TS is effective for providing cognitive training in laparoscopic cholecystectomies to medical students. It is likely that this effect will be seen across modules and other platforms that use cognitive task analysis alongside high-fidelity animation. Further work is necessary to extend this to other surgical procedures for evaluating its longitudinal effectiveness.

Journal article

Hall A, Leff D, Wojdecka A, Kinross J, Thompson P, Darzi Aet al., 2019, BEYOND THE HEALTHCARE PARADIGM: CO-CREATING A NEW MODEL FOR COLLABORATIVE TRANSDISCIPLINARY HEALTHCARE DESIGN EDUCATION, 21st International Conference on Engineering and Product Design Education (E and PDE), Publisher: DESIGN SOC

Conference paper

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://wlsprd.imperial.ac.uk:80/respub/WEB-INF/jsp/search-html.jsp Request URI: /respub/WEB-INF/jsp/search-html.jsp Query String: respub-action=search.html&id=00236600&limit=30&person=true