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.

I mage guidance systems are increasingly important tools in surgery and have been widely adopted in neurosurgery over the last decade. Nonetheless, the evidence for the effectiveness and safety of these image guidance systems remains limited. Case-control studies report that the use of image guidance is associated with improved patient outcomes when compared with standard surgery, 14 but commentators have suggested that clinical randomized studies are now neither practical nor ethical. 17The final component of all image guidance systems is the display of images in such a way that the surgeon is able to localize a point in the operative field unambiguously. Multiplanar reformatted mode has been used since the advent of CT imaging, and triplanar displays presenting axial, sagittal, and coronal views remain the most widely used technique. A drawback of triplanar displays is that surgeons must use the information from image slices to construct, in their own minds, a potentially complex 3D representation of anatomical and pathological structures. Moreover, triplanar displays require that surgeons stop operating momentarily, apply a probe to the region of interest (potentially near critical neurovascular structures), and then take their eyes off the surgical field to view the image guidance monitors. The fusion of virtual 3D models and the actual operating field to provide an augmented reality may enhance the operating room workflow. obJect Over the last decade, image guidance systems have been widely adopted in neurosurgery. Nonetheless, the evidence supporting the use of these systems in surgery remains limited. The aim of this study was to compare simultaneously the effectiveness and safety of various image guidance systems against that of standard surgery. methods In this preclinical, randomized study, 50 novice surgeons were allocated to one of the following groups: 1) no image guidance, 2) triplanar display, 3) always-on solid overlay, 4) always-on wire mesh overlay, and 5) 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 (in seconds) and tool path length (in mm). The secondary outcomes were recognition of an unexpected finding (i.e., a surgical clip) and subjective depth perception using a Likert scale. results The time to task completion and tool path length were significantly lower when using any form of image guidance compared with no image guidance (p < 0.001 and p = 0.003, respectively). The tool path distance was also lower in groups using augmented reality compared with triplanar display (p = 0.010). Always-on solid overlay resulted in the greatest inattentional blindness (20% recognition of unexpected finding). Wire mesh and on-demand overlays mitigated, but did not negate, inattentional blindness and were comparable to triplanar display (40% recognition of unexpected finding in all groups). Wire mesh and inverse realism overlays also resulted in better subjective depth perception...

Wellcome Trust.

In managing a patient with glioblastoma (GBM), a surgeon must carefully consider whether sufficient tumour can be removed so that the patient can enjoy the benefits of decompression and cytoreduction, without impacting on the patient's neurological status. In a previous study we identified the five most important anatomical features on a pre-operative MRi that are predictive of surgical resectability and used them to develop a simple, objective, and reproducible grading system. The objective of this study was to apply an artificial neural network (ANN) to improve the prediction of surgical resectability in patients with GBM. prospectively maintained databases were searched to identify adult patients with supratentorial GBM that underwent craniotomy and resection. performance of the Ann was evaluated against logistic regression and the standard grading system by analysing their Receiver operator characteristic (Roc) curves; Area Under curve (AUc) and accuracy were calculated and compared using Wilcoxon signed rank test with a value of p < 0.05 considered statistically significant. In all, 135 patients were included, of which 33 (24.4%) were found to have complete excision of all contrast-enhancing tumour. The AUC and accuracy were significantly greater using the ANN compared to the standard grading system (0.87 vs. 0.79 and 83% vs. 80% respectively; p < 0.01 in both cases). In conclusion, an Ann allows for the improved prediction of surgical resectability in patients with GBM.