IDEAL-D Framework for Device Innovation: A Consensus Statement on the Preclinical Stage.

OBJECTIVE: To extend the IDEAL framework for device innovation, IDEAL-D, to include the preclinical stage of development (stage 0). BACKGROUND: In previous work, the IDEAL collaboration has proposed frameworks for new surgical techniques and complex therapeutic technologies, the central tenet being that development and evaluation can and should proceed together in an ordered and logical manner that balances innovation and safety. METHODS: Following agreement at the IDEAL Collaboration Council, a multidisciplinary working group was formed comprising 12 representatives from healthcare, academia, industry, and a patient advocate. The group conducted a series of discussions following the principles used in the development of the original IDEAL framework. Importantly, IDEAL aims for maximal transparency, optimal validity in the evaluation of primary effects, and minimization of potential risk to patients or others. The proposals were subjected to further review and editing by members of the IDEAL Council before a final consensus version was adopted. RESULTS: In considering which studies are required before a first-in-human study, we have: (1) classified devices according to what they do and the risks they carry, (2) classified studies according to what they show about the device, and (3) made recommendations based on the principle that the more invasive and high risk a device is, the greater proof required of their safety and effectiveness before progression to clinical studies (stage 1). CONCLUSIONS: The proposed recommendations for preclinical evaluation of medical devices represent a proportionate and pragmatic approach that balances the de-risking of first-in-human translational studies against the benefits of rapid translation of new devices into clinical practice.

Perfect Registration Leads to Imperfect Performance: A Randomized Trial of Multimodal Intraoperative Image Guidance.

OBJECTIVE: To compare surgical safety and efficiency of 2 image guidance modalities, perfect augmented reality (AR) and side-by-side unregistered image guidance (IG), against a no guidance control (NG), when performing a simulated laparoscopic cholecystectomy (LC). BACKGROUND: Image guidance using AR offers the potential to improve understanding of subsurface anatomy, with positive ramifications for surgical safety and efficiency. No intra-abdominal study has demonstrated any advantage for the technology. Perfect AR cannot be provided in the operative setting in a patient; however, it can be generated in the simulated setting. METHODS: Thirty-six experienced surgeons performed a baseline LC using the LapMentor simulator before randomization to 1 of 3 study arms: AR, IG, or NG. Each performed 3 further LC. Safety and efficiency-related simulator metrics, and task workload (SURG-TLX) were collected. RESULTS: The IG group had a shorter total instrument path length and fewer movements than NG and AR groups. Both IG and NG took a significantly shorter time than AR to complete dissection of Calot triangle. Use of IG and AR resulted in significantly fewer perforations and serious complications than the NG group. IG had significantly fewer perforations and serious complications than the AR group. Compared with IG, AR guidance was found to be significantly more distracting. CONCLUSION: Side-by-side unregistered image guidance (IG) improved safety and surgical efficiency in a simulated setting when compared with AR or NG. IG provides a more tangible opportunity for integrating image guidance into existing surgical workflow as well as delivering the safety and efficiency benefits desired.

Predicting surgical outcome in patients with glioblastoma multiforme using pre-operative magnetic resonance imaging: development and preliminary validation of a grading system.

The lack of a simple, objective and reproducible system to describe glioblastoma multiforme (GBM) represents a major limitation in comparative effectiveness research. The objectives of this study were therefore to develop such a grading system and to validate it on patients who underwent surgical resection. A systematic review of the literature was performed to identify features on pre-operative magnetic resonance imaging (MRI) that predict the surgical outcome of patients with GBM. In all, the five most important features of GBM on pre-operative MRI were as follows: periventricular or deep location, corpus callosum or bilateral location, eloquent location, size and associated oedema. These were then used to develop a grading system. To validate this grading system, a retrospective cohort study of all adult patients with supratentorial GBM who underwent surgical resection between the 1 January 2014 and the 31 June 2015 was performed. There was a substantial agreement between the two neurosurgeons grading GBM (Cohen's κ was 0.625; standard error 0.066). High-complexity lesions were significantly less likely to result in complete resection of contrast-enhancing tumour than low-complexity lesions (50.0 versus 3.4%; p = 0.0007). The proposed grading system may allow for the standardised communication of anatomical features of GBM identified on pre-operative MRI.

Making the Leap: the Translation of Innovative Surgical Devices From the Laboratory to the Operating Room.

OBJECTIVE: To determine the rate and extent of translation of innovative surgical devices from the laboratory to first-in-human studies, and to evaluate the factors influencing such translation. SUMMARY BACKGROUND DATA: Innovative surgical devices have preceded many of the major advances in surgical practice. However, the process by which devices arising from academia find their way to translation remains poorly understood. METHODS: All biomedical engineering journals, and the 5 basic science journals with the highest impact factor, were searched between January 1993 and January 2000 using the Boolean search term "surgery OR surgeon OR surgical". Articles were included if they described the development of a new device and a surgical application was described. A recursive search of all citations to the article was performed using the Web of Science (Thompson-Reuters, New York, NY) to identify any associated first-in-human studies published by January 2015. Kaplan-Meier curves were constructed for the time to first-in-human studies. Factors influencing translation were evaluated using log-rank and Cox proportional hazards models. RESULTS: A total of 8297 articles were screened, and 205 publications describing unique devices were identified. The probability of a first-in-human at 10 years was 9.8%. Clinical involvement was a significant predictor of a first-in-human study (P = 0.02); devices developed with early clinical collaboration were over 6 times more likely to be translated than those without [RR 6.5 (95% confidence interval 0.9-48)]. CONCLUSIONS: These findings support initiatives to increase clinical translation through improved interactions between basic, translational, and clinical researchers.

Comparative effectiveness and safety of image guidance systems in surgery: a preclinical randomised study.

BACKGROUND: Over the past decade image guidance systems have been widely adopted in specialties such as neurosurgery and otorhinolaryngology. Nonetheless, the evidence supporting the use of image guidance systems in surgery remains limited. New augmented reality systems offer the possibility of enhanced operating room workflow compared with existing triplanar image displays, but recent studies have highlighted several concerns, particularly the risk of inattentional blindness and impaired depth perception. The aim of this study was to compare simultaneously the effectiveness and safety of various image guidance systems against standard surgery. METHODS: In this preclinical randomised study design 50 novice surgeons were allocated to no image guidance, triplanar display, always-on solid overlay, always-on wire mesh overlay, or on-demand inverse realism overlay. Each participant was asked to identify a basilar tip aneurysm in a validated model head. The primary outcomes were time to task completion, and tool path length. The secondary outcomes were recognition of an unexpected finding (a surgical clip) and subjective depth perception (using a Likert scale). FINDINGS: Surgeons' time to task completion and tool path length were significantly lower in groups using any form of image guidance than in groups with no image guidance (p<0·001 and p=0·003, respectively). The tool path distance was also lower in groups using augmented reality than in those using triplanar display (p=0·010). Always-on solid overlay resulted in the greatest inattentional blindness (20% recognition of unexpected finding by all surgeons). Wire mesh and on-demand overlays mitigated but did not negate inattentional blindness, and were comparable with triplanar display (40% recognition of unexpected finding in all groups). Wire mesh and inverse realism overlays also resulted in better subjective depth perception than always-on solid overlay (p=0·031 and p=0·008, respectively). INTERPRETATION: This study suggests that new augmented reality platforms incorporating always-on wire mesh and on-demand inverse realism might improve surgical performance, at least in novice surgeons. All image display modalities, including existing triplanar display, carry a risk of inattentional blindness. FUNDING: Wellcome Trust.

Assessing the impact of mass media public health campaigns. Be Clear on Cancer 'blood in pee': a case in point.

OBJECTIVES: To assess the impact on suspected cancer referral burden and new cancer diagnosis of Public Health England's recent Be Clear on Cancer 'blood in pee' mass media campaign. METHODS: A retrospective cohort study design was used. For two distinct time periods, August 2012 to May 2013 and August 2013 to May 2014, all referrals of patients deemed to be at risk of urological cancer by the referring primary healthcare physician to Imperial College NHS Healthcare Trust were screened. Data were collected on age and sex and whether the referral was for visible haematuria, non-visible haematuria or other suspected urological cancer. In addition to referral data, hospital episode data for all new renal cell (RCC) and upper and lower tract transitional cell carcinoma (TCC), as well as testicular and prostate cancer diagnoses for the same time periods were obtained. RESULTS: Over the campaign period and the subsequent 3 months, the number of haematuria referrals increased by 92% (P = 0.013) when compared with the same period a year earlier. This increase in referrals was not associated with a significant corresponding rise in cancer diagnosis; instead changes of 26.8% (P = 0.56) and -3.3% (P = 0.84) were seen in RCC and TCC, respectively. CONCLUSIONS: This study has shown that the Be Clear on Cancer 'blood in pee' mass media campaign significantly increased the number of new suspected cancer referrals, but there was no significant change in the diagnosis of target cancers across a large catchment. Mass media campaigns are expensive, require significant planning and appropriate implementation and, while the findings of this study do not challenge their fundamental objective, more work needs to be done to understand why no significant change in target cancers was observed. Further consideration should also be given to the increased referral burden that results from these campaigns, such that pre-emptive strategies, including educational and process mapping, across primary and secondary care can be implemented.

Comparative Performance in Single-Port Versus Multiport Minimally Invasive Surgery, and Small Versus Large Operative Working Spaces: A Preclinical Randomized Crossover Trial.

BACKGROUND: Surgical approaches such as transanal endoscopic microsurgery, which utilize small operative working spaces, and are necessarily single-port, are particularly demanding with standard instruments and have not been widely adopted. The aim of this study was to compare simultaneously surgical performance in single-port versus multiport approaches, and small versus large working spaces. METHODS: Ten novice, 4 intermediate, and 1 expert surgeons were recruited from a university hospital. A preclinical randomized crossover study design was implemented, comparing performance under the following conditions: (1) multiport approach and large working space, (2) multiport approach and intermediate working space, (3) single-port approach and large working space, (4) single-port approach and intermediate working space, and (5) single-port approach and small working space. In each case, participants performed a peg transfer and pattern cutting tasks, and each task repetition was scored. RESULTS: Intermediate and expert surgeons performed significantly better than novices in all conditions (P < .05). Performance in single-port surgery was significantly worse than multiport surgery (P < .01). In multiport surgery, there was a nonsignificant trend toward worsened performance in the intermediate versus large working space. In single-port surgery, there was a converse trend; performances in the intermediate and small working spaces were significantly better than in the large working space. CONCLUSIONS: Single-port approaches were significantly more technically challenging than multiport approaches, possibly reflecting loss of instrument triangulation. Surprisingly, in single-port approaches, in which triangulation was no longer a factor, performance in large working spaces was worse than in intermediate and small working spaces.

Robotic versus non-robotic instruments in spatially constrained operating workspaces: a pre-clinical randomized crossover study.

OBJECTIVE: To compare the effectiveness of robotic and non-robotic laparoscopic instruments in spatially constrained workspaces. MATERIALS AND METHODS: Surgeons performed intracorporeal sutures with various instruments within three different cylindrical workspace sizes. Three pairs of instruments were compared: 3-mm non-robotic mini-laparoscopy instruments; 5-mm robotic instruments; and 8-mm robotic instruments. Workspace diameters were 4, 6 and 8 cm, with volumes of 50, 113 and 201 cm(3) respectively. Primary outcomes were validated objective task performance scores and instrument workspace breach counts. RESULTS: A total of 23 participants performed 276 suture task repetitions. The overall median task performance scores for the 3-, 5- and 8-mm instruments were 421, 398 and 402, respectively (P = 0.12). Task scores were highest (best) for the 3-mm non-robotic instruments in all workspace sizes. Scores were significantly lower when spatial constraints were imposed, with median task scores for the 4-, 6- and 8-cm diameter workspaces being 388, 415 and 420, respectively (P = 0.026). Significant indirect relationships were seen between boundary breaches and workspace size (P < 0.001). Higher breach counts occurred with the robotic instruments. CONCLUSIONS: Smaller workspaces limit the performance of both robotic and non-robotic instruments. In operating workspaces <200 cm(3) , 3-mm non-robotic instruments are better suited for advanced bimanual operative tasks such as suturing. Future robotic instruments need further optimization if this technology is to be uniquely advantageous for clinical roles that involve endoscopic access to workspace-restricted anatomical areas.

Inattention blindness in surgery.

BACKGROUND: Inattention blindness (IB) can be defined as the failure to perceive an unexpected object when attention is focussed on another object or task. The principal aim of this study was to determine the effect of cognitive load and surgical image guidance on operative IB. METHODS: Using a randomised control study design, participants were allocated to a high or low cognitive load group and subsequently to one of three augmented reality (AR) image guidance groups (no guidance, wireframe overlay and solid overlay). Randomised participants watched a segment of video from a robotic partial nephrectomy. Those in the high cognitive load groups were asked to keep a count of instrument movements, while those in the low cognitive load groups were only asked to watch the video. Two foreign bodies were visible within the operative scene: a swab, within the periphery of vision; and a suture, in the centre of the operative scene. Once the participants had finished watching the video, they were asked to report whether they had observed a swab or suture. RESULTS: The overall level of prompted inattention blindness was 74 and 10 % for the swab and suture, respectively. Significantly higher levels of IB for the swab were seen in the high versus the low cognitive load groups, but not for the suture (8 vs. 47 %, p < 0.001 and 90 vs. 91 %, p = 1.000, for swab and suture, respectively). No significant difference was seen between image guidance groups for attention of the swab or suture (29 vs. 20 %, p = 0.520 and 22 vs. 22 %, p = 1.000, respectively). CONCLUSIONS: The overall effect of IB on operative practice appeared to be significant, within the context of this study. When examining for the effects of AR image guidance and cognitive load on IB, only the latter was found to have significance.

da Vinci robot-assisted keyhole neurosurgery: a cadaver study on feasibility and safety.

The goal of this cadaver study was to evaluate the feasibility and safety of da Vinci robot-assisted keyhole neurosurgery. Several keyhole craniotomies were fashioned including supraorbital subfrontal, retrosigmoid and supracerebellar infratentorial. In each case, a simple durotomy was performed, and the flap was retracted. The da Vinci surgical system was then used to perform arachnoid dissection towards the deep-seated intracranial cisterns. It was not possible to simultaneously pass the 12-mm endoscope and instruments through the keyhole craniotomy in any of the approaches performed, limiting visualization. The articulated instruments provided greater dexterity than existing tools, but the instrument arms could not be placed in parallel through the keyhole craniotomy and, therefore, could not be advanced to the deep cisterns without significant clashing. The da Vinci console offered considerable ergonomic advantages over the existing operating room arrangement, allowing the operating surgeon to remain non-sterile and seated comfortably throughout the procedure. However, the lack of haptic feedback was a notable limitation. In conclusion, while robotic platforms have the potential to greatly enhance the performance of transcranial approaches, there is strong justification for research into next-generation robots, better suited to keyhole neurosurgery.

Robotic surgery in children: adopt now, await, or dismiss?

The role of robot-assisted surgery in children remains controversial. This article aims to distil this debate into an evidence informed decision-making taxonomy; to adopt this technology (1) now, (2) later, or (3) not at all. Robot-assistance is safe, feasible and effective in selected cases as an adjunctive tool to enhance capabilities of minimally invasive surgery, as it is known today. At present, expectations of rigid multi-arm robotic systems to deliver higher quality care are over-estimated and poorly substantiated by evidence. Such systems are associated with high costs. Further comparative effectiveness evidence is needed to define the case-mix for which robot-assistance might be indicated. It seems unlikely that we should expect compelling patient benefits when it is only the mode of minimally invasive surgery that differs. Only large higher-volume institutions that share the robot amongst multiple specialty groups are likely to be able to sustain higher associated costs with today's technology. Nevertheless, there is great potential for next-generation surgical robotics to enable better ways to treat childhood surgical diseases through less invasive techniques that are not possible today. This will demand customized technology for selected patient populations or procedures. Several prototype robots exclusively designed for pediatric use are already under development. Financial affordability must be a high priority to ensure clinical accessibility.

Quantifying innovation in surgery.

OBJECTIVES: The objectives of this study were to assess the applicability of patents and publications as metrics of surgical technology and innovation; evaluate the historical relationship between patents and publications; develop a methodology that can be used to determine the rate of innovation growth in any given health care technology. BACKGROUND: The study of health care innovation represents an emerging academic field, yet it is limited by a lack of valid scientific methods for quantitative analysis. This article explores and cross-validates 2 innovation metrics using surgical technology as an exemplar. METHODS: Electronic patenting databases and the MEDLINE database were searched between 1980 and 2010 for "surgeon" OR "surgical" OR "surgery." Resulting patent codes were grouped into technology clusters. Growth curves were plotted for these technology clusters to establish the rate and characteristics of growth. RESULTS: The initial search retrieved 52,046 patents and 1,801,075 publications. The top performing technology cluster of the last 30 years was minimally invasive surgery. Robotic surgery, surgical staplers, and image guidance were the most emergent technology clusters. When examining the growth curves for these clusters they were found to follow an S-shaped pattern of growth, with the emergent technologies lying on the exponential phases of their respective growth curves. In addition, publication and patent counts were closely correlated in areas of technology expansion. CONCLUSIONS: This article demonstrates the utility of publically available patent and publication data to quantify innovations within surgical technology and proposes a novel methodology for assessing and forecasting areas of technological innovation.

Meta-analysis of robot-assisted vs conventional laparoscopic and open pyeloplasty in children.

OBJECTIVE: To critically analyse outcomes for robot-assisted pyeloplasty(RAP) vs conventional laparoscopic pyeloplasty (LP) or open pyeloplasty (OP) by systematic review and meta-analysis of published data. PATIENTS AND METHODS: Studies published up to December 2013 were identified from multiple literature databases. Only comparative studies investigating RAP vs LP or OP in children were included.Meta-analysis was performed using random-effects modelling.Heterogeneity, subgroup analysis, and quality scoring were assessed. Effect sizes were estimated by pooled odds ratios and weighted mean differences. Primary outcomes investigated were operative success, re-operation, conversions,postoperative complications, and urinary leakage. Secondary outcome measures were estimated blood loss (EBL), length of hospital stay (LOS), operating time (OT), analgesia requirement, and cost. RESULTS: In all, 12 observational studies met inclusion criteria, reporting outcomes of 384 RAP, 131 LP, and 164 OP procedures. No randomised controlled trials were identified. Pooled analyses determined no significant differences between RAP and LP or OP for all primary outcomes. Significant differences in favour of RAP were found for LOS (vs LP and OP). Borderline significant differences in favour of RAP were found for EBL(vs OP). OT was significantly longer for RAP vs OP. Limited evidence indicates lower opiate analgesia requirement for RAP(vs LP and OP), higher total costs for RAP vs OP, and comparable costs for RAP vs LP. CONCLUSIONS: Existing evidence shows largely comparable outcomes amongst surgical techniques available to treat pelvi-ureteric junction obstruction in children. RAP may offer shortened LOS, lower analgesia requirement (vs LP and OP), and lower EBL (vs OP); but compared with OP, these gains are at the expense of higher cost and longer OT. Higher quality evidence from prospective observational studies and clinical trials is required, as well as further cost-effectiveness analyses. Not all perceived benefits of RAP are easily amenable to quantitative assessment.

Endoscopic and keyhole endoscope-assisted neurosurgical approaches: a qualitative survey on technical challenges and technological solutions.

INTRODUCTION: The literature reflects a resurgence of interest in endoscopic and keyhole endoscope-assisted neurosurgical approaches as alternatives to conventional microsurgical approaches in carefully selected cases. The aim of this study was to assess the technical challenges of neuroendoscopy, and the scope for technological innovations to overcome these barriers. MATERIALS AND METHODS: All full members of the Society of British Neurosurgeons (SBNS) were electronically invited to participate in an online survey. The open-ended structured survey asked three questions; firstly, whether the surgeon presently utilises or has experience with endoscopic or endoscope-assisted approaches; secondly, what they consider to be the major technical barriers to adopting such approaches; and thirdly, what technological advances they foresee improving safety and efficacy in the field. Responses were subjected to a qualitative research method of multi-rater emergent theme analysis. RESULTS: Three clear themes emerged: 1) surgical approach and better integration with image-guidance systems (20%), 2) intra-operative visualisation and improvements in neuroendoscopy (49%), and 3) surgical manipulation and improvements in instruments (74%). DISCUSSION: The analysis of responses to our open-ended survey revealed that although opinion was varied three major themes could be identified. Emerging technological advances such as augmented reality, high-definition stereo-endoscopy, and robotic joint-wristed instruments may help overcome the technical difficulties associated with neuroendoscopic approaches. CONCLUSIONS: Results of this qualitative survey provide consensus amongst the technology end-user community such that unambiguous goals and priorities may be defined. Systems integrating these advances could improve the safety and efficacy of endoscopic and endoscope-assisted neurosurgical approaches.

Global trends in paediatric robot-assisted urological surgery: a bibliometric and Progressive Scholarly Acceptance analysis.

The inaugural robot-assisted urological procedure in a child was performed in 2002. This study aims to catalogue the impact of this technology by utilizing bibliographic data as a surrogate measure for global diffusion activity and to appraise the quality of evidence in this field. A systematic literature search was performed to retrieve all reported cases of paediatric robot-assisted urological surgery published between 2003 and 2016. The status of scientific community acceptance was determined using a newly developed analysis model named progressive scholarly acceptance. A total of 151 publications were identified that reported 3688 procedures in 3372 patients. The most reported procedures were pyeloplasty (n = 1923) and ureteral reimplantation (n = 1120). There were 16 countries and 48 institutions represented in the literature. On average, the total case volume reported in the literature more than doubled each year (mean value increase 236.6% per annum). The level of evidence for original studies remains limited to case reports, case series and retrospective comparative studies. Progressive Scholarly Acceptance charts indicate that robot-assisted techniques for pyeloplasty or ureteral reimplantation are yet to be accepted by the scientific community. Global adoption trends for robotic surgery in paediatric urology have been progressive but remain low volume. Pyeloplasty and ureteral reimplantation are dominant applications. Robot-assisted techniques for these procedures are not supported by high quality evidence at present. Next-generation robots are forecast to be smaller, cheaper, more advanced and customized for paediatric patients. Ongoing critical evaluation must occur simultaneously with expected technology evolution.

Trends in the diffusion of robotic surgery: A retrospective observational study.

BACKGROUND: Recent studies have suggested that the use of robotic surgery for prostatectomy has been increasing, but characterization of the diffusion of robotic surgery in other procedures has not been available. METHODS: Data were analysed for the years 2006-2014 using hospital episode statistics (HES), a database of all admissions to National Health Service (NHS) hospitals in England. OPCS codes were used to determine the annual number of prostatectomy, partial nephrectomy, and total abdominal hysterectomy procedures. Concurrent OPCS codes were then used to identify whether these procedures were robotic, conventional laparoscopic or open surgery. RESULTS: The proportion of robotic cases varied depending on the surgical procedure. Diffusion of robotic surgery was relatively rapid in prostatectomy, moderate in partial nephrectomy, and slow in total abdominal hysterectomy. CONCLUSIONS: Although high institutional cost might explain the earliest delays in diffusion, this barrier does not fully account for the different rates of diffusion among surgical procedures.

Fifty Years of Innovation in Plastic Surgery.

BACKGROUND: Innovation has molded the current landscape of plastic surgery. However, documentation of this process only exists scattered throughout the literature as individual articles. The few attempts made to profile innovation in plastic surgery have been narrative, and therefore qualitative and inherently biased. Through the implementation of a novel innovation metric, this work aims to identify and characterise the most prevalent innovations in plastic surgery over the last 50 years. METHODS: Patents and publications related to plastic surgery (1960 to 2010) were retrieved from patent and MEDLINE databases, respectively. The most active patent codes were identified and grouped into technology areas, which were subsequently plotted graphically against publication data. Expert-derived technologies outside of the top performing patents areas were additionally explored. RESULTS: Between 1960 and 2010, 4,651 patents and 43,118 publications related to plastic surgery were identified. The most active patent codes were grouped under reconstructive prostheses, implants, instruments, non-invasive techniques, and tissue engineering. Of these areas and other expert-derived technologies, those currently undergoing growth include surgical instruments, implants, non-invasive practices, transplantation and breast surgery. Innovations related to microvascular surgery, liposuction, tissue engineering, lasers and prostheses have all plateaued. CONCLUSIONS: The application of a novel metric for evaluating innovation quantitatively outlines the natural history of technologies fundamental to the evolution of plastic surgery. Analysis of current innovation trends provides some insight into which technology domains are the most active.

Using preoperative imaging for intraoperative guidance: a case of mistaken identity.

BACKGROUND: Surgical image guidance systems to date have tended to rely on reconstructions of preoperative datasets. This paper assesses the accuracy of these reconstructions to establish whether they are appropriate for use in image guidance platforms. METHODS: Nine raters (two experts in image interpretation and preparation, three in image interpretation, and four in neither interpretation nor preparation) were asked to perform a segmentation of ten renal tumours (four cystic and six solid tumours). These segmentations were compared with a gold standard consensus segmentation generated using a previously validated algorithm. RESULTS: Average sensitivity and positive predictive value (PPV) were 0.902 and 0.891, respectively. When assessing for variability between raters, significant differences were seen in the PPV, sensitivity and incursions and excursions from consensus tumour boundary. CONCLUSIONS: This paper has demonstrated that the interpretation required for the segmentation of preoperative imaging of renal tumours introduces significant inconsistency and inaccuracy. Copyright © 2015 John Wiley & Sons, Ltd.

Regulatory approval of new medical devices: cross sectional study.

OBJECTIVE:  To investigate the regulatory approval of new medical devices. DESIGN:  Cross sectional study of new medical devices reported in the biomedical literature. DATA SOURCES:  PubMed was searched between 1 January 2000 and 31 December 2004 to identify clinical studies of new medical devices. The search was carried out during this period to allow time for regulatory approval. ELIGIBILITY CRITERIA FOR STUDY SELECTION:  Articles were included if they reported a clinical study of a new medical device and there was no evidence of a previous clinical study in the literature. We defined a medical device according to the US Food and Drug Administration as an "instrument, apparatus, implement, machine, contrivance, implant, in vitro reagent, or other similar or related article." MAIN OUTCOME MEASURES:  Type of device, target specialty, and involvement of academia or of industry for each clinical study. The FDA medical databases were then searched for clearance or approval relevant to the device. RESULTS:  5574 titles and abstracts were screened, 493 full text articles assessed for eligibility, and 218 clinical studies of new medical devices included. In all, 99/218 (45%) of the devices described in clinical studies ultimately received regulatory clearance or approval. These included 510(k) clearance for devices determined to be "substantially equivalent" to another legally marketed device (78/99; 79%), premarket approval for high risk devices (17/99; 17%), and others (4/99; 4%). Of these, 43 devices (43/99; 43%) were actually cleared or approved before a clinical study was published. CONCLUSIONS:  We identified a multitude of new medical devices in clinical studies, almost half of which received regulatory clearance or approval. The 510(k) pathway was most commonly used, and clearance often preceded the first published clinical study.