Augmented reality for teaching anatomy.

Successive waves of the coronavirus (COVID-19) pandemic lockdowns resulted in significant reduction in face-to-face teaching, with an adverse effect especially on sectors requiring direct skill acquisition. Despite the fact that augmented reality (AR) presents an equitable, cost-effective solution which reduces crowding in the confined spaces of the dissection theater, the benefits of AR-supported undergraduate medical education have been poorly investigated. We conducted a validated survey to explore the value of AR in the dissection theater and assess its impact from the learner's perspective. Further to a validated pilot (n = 30), a larger scale study (n = 130) was conducted to assess the introduction of AR across three different learning domains: retaining anatomy detail, perception of spatial anatomical relations, and speed of learning. A response rate of 85.4% was reported. Our results suggest that the use of AR technology leads to a significant enhancement of spatial relations, faster detailed material assimilation and assistance in understanding of key concepts. In addition, most participants opt to recommend AR as a valuable tool in the learning process. In view of the proposed added value of AR technology in various teaching aspects, we recommend that AR should be introduced as a standard practice in both pre- and postgraduate medical curricula and suggest further research regarding the use of this technology.

Picosecond laser versus historical responses to Q-switched lasers for tattoo treatment.

BackgroundTattooing is increasingly common among adolescents and young adults. This study explores the clinical efficacy of picosecond laser for the correction of tattoos. Literature suggests that 25-47% of the population have had a tattoo at some point in their life (1). The incidence is slightly higher in adults 18-35 years (22-47%) compared to college students (18-25 years of age(1, 2). Recent surveys report 25% of tattooed adults expressing regret, while 4% of tattooed students had already undergone some form of tattoo-removal procedure (3). A common request for tattoo removal includes poorly executed tattoos, avoidance of stigmatization, trauma, socially inappropriate, and employment. Several procedures have been proposed to remove tattoos including cryosurgery, thermal cautery, or surgical resection (4). A major disadvantage of these methods is that they are all highly operator dependent, and carry a very high risk of residual scarring, residual pigment being left behind "ghosting" (3). In addition, some opt to cover the unwanted tattoo with another design, which results in layered tattoos that are substantially harder to manage. Laser surgery, in skilled hands, is an effective method for tattoo removal and traditionally, this is performed with Quality-Switched Laser, where energy liberatred in the nanosecond range results in a selective photothermal effect (5). Picosecond laser is a more recent innovation that results in energy released in a picosecond timescale (a time interval 1000 times shorter).One potential disavantage of laser therapy for the effacement of cutaneous tattoos is the length of treatment and associated cost, which might dissuade the patient from following through to completion of treatment, limiting potential benefits whilst still being exposed to risk of harm. (5, 6). Recent studies suggest that picosecond laser result in substantially reduced treatment times, whilst achieving an identical or more effective end result (7-9). However, these studies are limited by very small sample size and follow-up.

Development and validation of an in vitro pharmacokinetic/pharmacodynamic model to test the antibacterial efficacy of antibiotic polymer conjugates.

This study describes the use of a novel, two-compartment, static dialysis bag model to study the release, diffusion, and antibacterial activity of a novel, bioresponsive dextrin-colistin polymer conjugate against multidrug resistant (MDR) wild-type Acinetobacter baumannii. In this model, colistin sulfate, at its MIC, produced a rapid and extensive drop in viable bacterial counts (<2 log10 CFU/ml at 4 h); however, a marked recovery was observed thereafter, with regrowth equivalent to that of control by 48 h. In contrast, dextrin-colistin conjugate, at its MIC, suppressed bacterial growth for up to 48 h, with 3 log10 CFU/ml lower bacterial counts after 48 h than those of controls. Doubling the concentration of dextrin-colistin conjugate (to 2× MIC) led to an initial bacterial killing of 3 log10 CFU/ml at 8 h, with a similar regrowth profile to 1× MIC treatment thereafter. The addition of colistin sulfate (1× MIC) to dextrin-colistin conjugate (1× MIC) resulted in undetectable bacterial counts after 4 h, followed by suppressed bacterial growth (3.5 log10 CFU/ml lower than that of control at 48 h). Incubation of dextrin-colistin conjugates with infected wound exudate from a series of burn patients (n = 6) revealed an increasing concentration of unmasked colistin in the outer compartment (OC) over time (up to 86.3% of the initial dose at 48 h), confirming that colistin would be liberated from the conjugate by endogenous α-amylase within the wound environment. These studies confirm the utility of this model system to simulate the pharmacokinetics of colistin formation in humans administered dextrin-colistin conjugates and further supports the development of antibiotic polymer conjugates in the treatment of MDR infections.

Dextrin-colistin conjugates as a model bioresponsive treatment for multidrug resistant bacterial infections.

Polymer therapeutics offer potential benefits in the treatment of multidrug resistant (MDR) infections; affording targeted delivery of biologically active agents to the site of inflammation, potential decreases in systemic toxicity, and the retention of antimicrobial activity at the target site. As a prototype model, these studies developed and characterized a library of dextrin-colistin conjugates (dextrin molecular weight: 7500-48,000 g/mol) as a means of targeting the delivery of colistin. Optimum colistin release kinetics (following dextrin degradation by physiological concentrations of amylase (100 IU/L)) were observed in conjugates containing low molecular weight (∼7500 g/mol) dextrin with ∼1 mol % succinoylation (∼80% drug release within 48 h, compared to ∼33% from sodium colistin methanesulfonate (CMS, Colomycin)). These conjugates exhibited comparable antimicrobial activity to CMS in conventional MIC assays against a range of Gram-negative pathogens, but with significantly reduced in vitro toxicity toward kidney (IC50 = CMS, 15.4 µg/mL; dextrin-colistin, 63.9 µg/mL) and macrophage (IC50 = CMS, 111.3 µg/mL; dextrin-colistin, 303.9 µg/mL) cells. In vivo dose-escalation studies in rats demonstrated improved pharmacokinetics of the conjugates, with prolonged plasma levels of colistin (t1/2 135-1271 min vs 53 min) and decreased toxicity, compared to colistin sulfate. These studies highlight the potential utility of "nanoantibiotic" polymer therapeutics to aid the safe, effective, and targeted delivery of colistin in the management of MDR infections.

Unveiling the language of scars: A patient-centric themed framework for comprehensive scar morphology.

BACKGROUND: Scarring, a pervasive issue spanning across medical disciplines, lacks a comprehensive terminology for effective communication, patient engagement, and outcome assessment. Existing scar classification systems are constrained by specific pathologies, physician-centric features, and inadequately account for emerging technologies. This study refrains from proposing yet another classification system and instead revisits the foundational language of scar morphology through a theme analysis of primary patient complaints. METHOD: Data encompassing five years of a high-volume scar practice was analysed. Primary complaints were aggregated into collective descriptors and further organized into theme domains. The resulting hierarchical map of presenting complaints revealed five key domains: Loss of Function, Contour, Texture, Vector, and Colour Presenting complaints were codified into 42 items, which were then categorised into 14 collective descriptor terms. The latter were in turn organised into five overarching themes. RESULT: Loss of Function, accounting for 10% of primary concerns, signifies reduced function attributed solely to the scar. Contour, encompassing 41% of concerns, pertains to scar height, shape, and depth. Texture, representing 12% of concerns, denotes tactile variations such as hardness, roughness, and moisture. Vector, comprising 13% of concerns, refers to scar tissue tension and associated distortions. Colour, the concern in 24% of cases, encompasses variations in pigmentation, vascularity, and exogenous pigments. DISCUSSION: Standardized terminology enhances patient care, communication, and research. This study underscores the fundamental question of "what bothers the patient," reviving a patient-centred approach to scar management. By prioritizing themes based on patient complaints, this study innovatively integrates function, aesthetics, and patient experience. In conclusion, this study pioneers a paradigm shift in scar management by presenting a patient-driven theme framework that offers a common language for healthcare professionals and patients. Embracing this language harmonizes scar treatment, fosters innovation, and transforms scars from silent reminders into stories of resilience and healing.

The enhanced permeability retention effect: a new paradigm for drug targeting in infection.

Multidrug-resistant, Gram-negative infection is a major global determinant of morbidity, mortality and cost of care. The advent of nanomedicine has enabled tailored engineering of macromolecular constructs, permitting increasingly selective targeting, alteration of volume of distribution and activity/toxicity. Macromolecules tend to passively and preferentially accumulate at sites of enhanced vascular permeability and are then retained. This enhanced permeability and retention (EPR) effect, whilst recognized as a major breakthrough in anti-tumoral targeting, has not yet been fully exploited in infection. Shared pathophysiological pathways in both cancer and infection are evident and a number of novel nanomedicines have shown promise in selective, passive, size-mediated targeting to infection. This review describes the similarities and parallels in pathophysiological pathways at molecular, cellular and circulatory levels between inflammation/infection and cancer therapy, where use of this principle has been established.

Application of topical negative pressure (vacuum-assisted closure) to split-thickness skin grafts: a structured evidence-based review.

INTRODUCTION: Significant controversy surrounds the effectiveness of negative pressure wound therapy although it has been in use for decades. Although many clinicians favor this modality in relation to its practicality, ease of use especially in complex wounds, it has faced the same challenges as other dressings in relation to evidence base of efficacy in relation to a number of outcome measures. In view of the current financial pressures on health care systems worldwide, this structured review systematically challenges the evidence for perioperative application of topical negative pressure (TNP) to split-thickness skin grafts (STSGs) through evidence-based critical appraisal, and extrapolate the mechanisms of action on the mechanisms through which TNP may aid wound healing. Weighted evidence-based recommendations regarding the impact of TNP on split skin graft quality and quantity of take as outcomes. METHODS: Phase 1: Structured literature search. Phase 2: Retrieved articles were critically appraised for rigor and methodological validity by 3 independent authors, then stratified according to a validated "levels of evidence" framework. Graded "current best evidence" recommendations could therefore be proposed. RESULTS: Of the 220 studies retrieved in the initial search, 38 studies satisfied our quality of evidence criteria. Current best evidence supports 2 complementary trends explaining the mechanisms whereby STSG benefits from TNP. Active stimulation of epithelial mitosis: TNP creates mechanical stretch which stimulates multiple signaling pathways up-regulating growth- and mitosis-associated epithelial transcription factors. Topical negative pressure also promotes microcirculatory flow (graft and wound edge), stimulates angiogenesis and basement membrane integrity (grade C). Prevention of complications: significant reduction of graft lift-off by edema, exudates, subgraft hematoma, and reduction of shear when compared to traditional dressings (grade B). Topical negative pressure promotes significant qualitative improvement in the final STSG result studies (level 1B). The role of TNP in prevention of infection is, however, equivocal and further research is required. No evidence of harm from TNP application was reported. CONCLUSIONS: Topical negative pressure increases quantity and quality of split skin graft take compared to traditional bolster dressings. The advantages are increased in irregularly contoured, technically difficult wounds and suboptimal recipient wound beds where it seems to be the best modality currently available. Large-scale randomized clinical controlled trials remain scanty in all areas of wound dressing research including negative pressure therapy.

Sharps and needlestick injuries within the operating room: Risk prone procedures and prevalence meta-analysis.

BACKGROUND: Sharps and needlestick injuries pose a serious risk to operating theatre personnel with considerable morbidity, mortality and healthcare implications. The cost of prophylaxis and post-exposure treatment is a significant institutional economic burden. AIM: The aim of the review was to identify the prevalence of sharps and needlestick injury within the operating theatre and to establish the most common critical steps. METHOD: A systematic literature search was conducted. Abstracts of all studies published in English from 2015 onwards exploring sharps and needlestick injury within the operating theatre were reviewed. Primary outcome measure was sharps and needlestick injury prevalence. Secondary outcome measures included operational steps resulting in sharps and needlestick injury and costs of sharps and needlestick injury management. RESULTS: Sixteen studies were identified and included in analysis. Cross-sectional studies reported a pooled prevalence of 41.5% (n = 537; 95% confidence interval = 15.961 to 70.220). Retrospective data analysis reported an annualised prevalence of 5.027% (95% confidence interval = 0.676 to 13.073) on a total pooled sample population of 12,929. Further analysis of operational steps identified a 22% prevalence (n= 3460; 95% confidence interval = 14.2 to 31.3) of sharps and needlestick injury occurring during a procedure involving handing or receiving an instrument. CONCLUSION: Sharps and needlestick injuries are a significant but preventable risk in the operating theatre. Further research into the development of safety devices to reduce injury during instrument transfer is paramount.

The efficacy of medicinal leeches in plastic and reconstructive surgery: a systematic review of 277 reported clinical cases.

BACKGROUND: Although there are numerous case reports and small case series describing the experiences of leech therapy in various circumstances, there are relatively few large studies evaluating the effectiveness of leeching to relieve venous congestion. The therapeutic value of leeching is illustrated by these reports but the current literature lacks a cohesive summary of previous experiences. METHODS: An electronic search of PubMed, the Cochrane library and the Centre for Reviews and Dissemination between 1966 and 2009 was used to retrieve human studies published in the English language evaluating outcomes following leech therapy. The "success" and "failure" of leech therapy were the primary outcome measures and secondary outcomes included complications, number of leeches used, pharmacological adjuncts and blood transfusion requirements. RESULTS: In total, out of 461 articles, 394 articles met the exclusion criteria. The 67 included papers reported on 277 cases of leech use with an age range of 2-81 years and a male to female ratio of almost 2:1. The overall reported "success" rate following leech therapy was 77.98% (216/277). In terms of secondary outcome measures, 49.75% of cases (N = 101) required blood transfusions, 79.05% received antibiotics (N = 166) and 54.29% received concomitant anticoagulant therapy. The overall complication rate was 21.8%. CONCLUSION: In the absence of robust randomized controlled trials on which the evidence may be based, this synthesis of current best evidence guides clinicians during the process of consenting patients and using leeches in their practice.

Medicinal leeches and the microsurgeon: a four-year study, clinical series and risk benefit review.

BACKGROUND: There are case reports and small series in the literature relating to the use of medicinal leeches by plastic surgeons; however, larger series from individual units are rare. The aim of this article is to present a comprehensive 4-year case series of the use of medicinal leeches, discuss the current evidence regarding indications, risks, and benefits and highlight the recent updates regarding leech speciation. METHODS: Patients prescribed leeches in a 4-year period (July 2004-2008) were collated from hospital pharmacy records (N = 35). The number of leeches used, demographic, clinical, and microbiological details were retrospectively analyzed. RESULTS: Thirty-five patients were treated with leeches. The age range was 2 to 98 years (mean = 49.3). Leeches were most commonly used for venous congestion in pedicled flaps and replantations. Blood transfusions were necessary in 12 cases (34%) [mean = 2.8 units, range 2-5 units]. Our infection rate was 20% (7/35) including five infections with Aeromonas spp. (14.2%). The proportion of patients becoming infected after leech therapy was significantly greater in the group of patients that did not receive prophylactic antibiotic treatment (Fisher's Exact test P = 0.0005). In total, 14 cases (40%) were salvaged in entirety, in 7 cases 80% or more, in 2 cases 50 to 79%, and in 1 case less than 50% of the tissues were salvaged. In 11 cases (31%), the tissues were totally lost. CONCLUSION: Our study highlights both the benefits and the risks to patients in selected clinical situations and also the potential risks. The routine use of antibiotic prophylaxis is supported. In view of the emerging evidence that Hirudo verbana are now used as standard leech therapy, and the primary pathogen is Aeromonas veronii, until a large prospective multicenter study is published, large series of patients treated with leeches should be reported.

Chemical and mechanical alternatives to leech therapy: a systematic review and critical appraisal.

Although leech therapy is a well-established, effective method of relieving venous congestion, it is associated with complications such as wound infection and leech migration. To minimize these risks, efforts to reproduce their effects have been developed and investigated. A search string using (chemical OR mechanical OR alternative) AND (Leeches OR HIRUDO MEDICINALIS) in Boolean format was used across the major electronic databases to cover the past 10 years. Selected references were subsequently validated against critical appraisal frameworks and classified and evaluated against a framework of hierarchies of evidence. Out of 95 retrieved studies, 25 articles were selected after content appraisal. Of these, 12 articles were methodologically and statistically robust. The heterogeneity noted in the studies precluded meta-analysis of the results. The studies infer evidence at Grade B level that current device prototypes show proof of concept by providing suction and chemical anticoagulation following a surgically created wound. Although progress had been made to replicate leech action, there are still areas to address in future research. This article represents the current state of play in clinical translation of these concepts, providing efficacious devices without the drawbacks of traditional leech therapy.

Value of clinical, ultrasonographic and MRI signs as diagnostic differentiators of non-benign lipomatous tumours.

Suspicion of malignant change within a lipoma is a common and increasing workload within the UK Sarcoma multidisciplinary team (MDT) network, and a source of considerable patient anxiety. Currently, there is no lipoma-specific data, with regard to which clinical or radiographic features predict non-benign histology, or calculate an odds-ratio specific to a lipomatous lesion being non-benign. We performed a 9-year, double-blind, unmatched cohort study, comparing post-operative histology outcomes (benign versus non-benign) versus 15 signs across three domains: Clinical (size of tumour, depth, growth noticed by patient, previous lipoma, patient felt pain), Ultrasonographic (size, depth, vascularity, heterogenous features, septae) and MRI (size, depth, vascularity, heterogenous features, septae, complete fat signal suppression). Receiver operating characteristic (ROC) analysis, odds ratios and binary logistic regression analysis was performed double-blind. When each sign is considered independently, (ROC analysis, followed by binary logistic regression) only Ultrasound depth is a significant predictor (p = 0.044) of a histologically non-benign lipoma. Ultrasonographically determined vascularity and septation were not statistically significant predictors. None of the clinical signs were statistically significant (p > 0.05). Of the MRI signs none was statistically significant (p > 0.05). However, heterogeneous MRI features fared better than MRI depth. Ultrasound signs (Pseudo R-Square = 0.105) are more predictive of the post-operation histology outcome than Clinical signs (Pseudo R-Square = 0.082) or MRI tests (Pseudo R-Square = 0.052) Ultrasound and Clinical tests combined (Pseudo R-Square = 0.147) are more predictive of the post-operation histology outcome than MRI tests (Pseudo R-Square = 0.052). This work challenges the traditional perception of "red-flag" signs when applied to lipomatous tumours. We provide accurate data upon which an informed choice can be made, and provides a robust bases for expedited risk/benefit. The importance of an experienced and cohesive MDT network is emphasised.

Cutaneous laser surgery for secondary burn reconstruction: Cost benefit analysis.

Thermal disease presents a major burden to individual patient morbidity, healthcare cost as well as to over all economy. Burns also also represent a significant per-patient utlilisation of finite healthcare resources. Secondary complications in these patients, such as multiple drug resistant organisms, may have a devastating effect. Laser surgery has recently come of age as an optimal tool in the secondary reconstruction of burn injury, that is able to simultaneously address significant sheet scar tightness, hypertrophic, atrophic, and keloid complications, pruritus, microstomia, ectropion, skin graft honeycombing, and improve range of movement whilst reducing the risk of infection to <1%. Yet, cutaneous laser surgery is often underutilised due to the perceived concerns about the sustainability of a new service with relatively high startup cost. We present a dual methodology to explore this concern: an evidence-based background review of the last 5 years of current best evidence, and a 22-year cost-analysis comparison at an established, high volume UK Centre of reconstructive surgery. We report that fiscal viability for laser surgery services for secondary burn reconstruction is supported by: level 2 (one systematic review) level 4 evidence (2 studies) and level 5 evidence (expert reports). Evidence over 22 years from an established super-regional NHS laser centre shows that introduction of this service led to sustained and substantial cost saving, producing excellent surgical results at a fraction of the cost of traditional surgery. Analysis of the potential dollar-effect of these advantages to the general population supports state investment in expertise and capital equipment as a medium to long-term cost saving strategy, which may also aid re-integrating patients into the workforce making a meaningful contribution to the economy.

New Developments for Fractional Co2 Resurfacing for Skin Rejuvenation and Scar Reduction.

Fractional CO2 procedures are an established, safe and effective armamentarium for managing skin rejuvenation and scarring. Very short-pulse-duration devices offer a very high ablated volume/ablated surface ratio, inducing a controlled thermal damage. With this kind of device, each procedure can be customized on the features of the skin of each patient. The same device can be used to treat severe burn scars. With a very deep fractional procedure on a scar tissue, immediate relaxation of the tension and retraction forces may be obtained, and downstream, improvements are related more to the activation of a molecular cascade. The authors review the state-of-the-art, in the use of fractioned CO2 laser technology for aesthetic and scar remodelling indications.

Preventing infective complications following leech therapy: is practice keeping pace with current research?

BACKGROUND: Despite several publications strongly advocating prophylactic antibiotics during leech therapy, and recent primary articles shedding new light on the microbiota of leeches, many units either do not use antibiotic prophylaxis, or are continuing to use ineffective agents. METHODS: A 5-year follow-up of plastic surgery units in the United Kingdom and the Republic of Ireland was conducted in 2007 to ascertain current practice regarding the use of prophylactic antibiotics with leech therapy. A comprehensive literature search investigated primary research articles regarding the microbiota of leeches to update the reconstructive surgery community. RESULTS: Despite published evidence to support the use of prophylactic antibiotics during leech therapy, 24% of units do not use antibiotic prophylaxis and 57% of those using antibiotics are using potentially ineffective agents. Advanced molecular genetic techniques, which allow accurate characterization of both culturable and non-culturable microbiota of the leech digestive tract, show a wider diversity than at first thought, with variable antibiotic resistance profiles. CONCLUSIONS: Despite infection due to leech therapy being a well known and relatively common complication, many units are not using appropriate antibiotic prophylaxis.

Lasers and ancillary treatments for scar management Part 2: Keloid, hypertrophic, pigmented and acne scars.

The formation of a wide range of excessive scars following various skin injuries is a natural consequence of healing. Scars resulting from surgery or trauma affect approximately 100 million people per annum in the developed world and can have profound physical, aesthetic, psychological and social consequences. Thus, scar treatment is a priority for patient and physician alike. Laser treatment plays an important role in scar management with additional support from ancillary modalities. Subsequent to part 1: Burns scars, part 2 focuses on our strategies and literature review of treatment of keloid, hypertrophic, pigmented and acne scars where lasers are used in conjunction with other measures, and illustrated with case studies.

Measuring coagulation in burns: an evidence-based systematic review.

INTRODUCTION: Dynamic monitoring of coagulation is important to predict both haemorrhagic and thrombotic complications and to guide blood product administration. Reducing blood loss and tailoring blood product administration may improve patient outcome and reduce mortality associated with transfusion. The current literature lacks a systematic, critical appraisal of current best evidence on which clinical decisions may be based. OBJECTIVES: Establishing the role of different coagulation markers in burn patients, diagnosing coagulopathy, tailoring blood product administration and indicating prognosis. METHODS: Literature during 2004-2017 from the Cochrane Library, PubMed, Scopus, Medline and Embase was reviewed. Eligibility criteria included randomised controlled trials, systematic reviews, multi-/single-centre study and meta-analyses. Keywords searched were 'burns', 'blood coagulation disorders', 'rotem', 'blood coagulation' and 'thromboelastography'. The PRISMA flow system was used for stratification and the CASP framework for appraisal of the studies retrieved. RESULTS: In total, 13 articles were included after inclusion/exclusion criteria had been applied to the initial 79 studies retrieved. Hypercoagulation increases in proportion to the severity of thermal injury. Whole blood testing, using thrombelastography (TEG) and rotation thromboelastometry (ROTEM), was superior to standard plasma based tests, including prothrombin time (PT) and activated partial thromboplastin time (APTT) at detecting burn-related coagulopathies. CONCLUSIONS: Routine laboratory markers such as PT/APTT are poor indicators of coagulation status in burns patients. Viscoelastic tests, such as TEG and ROTEM, are efficient, fast and have a potential use in the management of burn patients; however, strong evidence is lacking. This review highlights the need for more randomised controlled trials, to guide future practice.

Chromophores in operative surgery: Current practice and rationalized development.

BACKGROUND: Chromophore-containing molecules feature extensively in surgical practice, with synthetic dyes gaining popularity over endogenous optical adjuncts. New applications for chromophores in diagnostics and operative treatment exploit unique chemical structures suited for illuminating target tissues beyond the visual spectrum, ranging from ultraviolet (UV) to near-infrared (NIR). This review outlines the rationale for surgical chromophore application, the weaknesses and risks in each class of these compounds, and areas of foreseeable potential for employment of specialized contrast agents. METHOD: An English-language literature search applied the following Boolean Search String: "dye OR Lake OR Stain OR chromophore" AND "tox$ OR terato* OR carcino$ OR Allerg$ OR surg$ OR clinic" using EMBASE, PUBMED, PUBMED central and OVIDSp, with back-referencing through Web of Knowledge™. RESULTS: Based on the primary literature, this study proposes a surgically relevant classification system of chromophores in current use, which facilitates risk/benefit consideration for the surgeon who employs them, and which facilitates clinically oriented development. CONCLUSIONS: The next stage of development for optically active surgical adjuncts must address practical constraints whilst minimizing risks of adverse effects. Exploiting the technology's full potential also requires improvements in the usefulness of imagery equipment.