Vr 4 VP shunt

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  • Highest tumour to background uptake: Fchol > FET > FDG. But all have increased uptake in inflammatory cells around necrosis.
  • Vr 4 VP shunt

    1. 1. VIRTUAL REALITY FOR OCCIPITAL HORN CATHETRERISATION IN VENTRICULOPERITONEAL SHUNT AS AN EDUCATIONAL TASK Sanmugarajah Paramasvaran ASAM
    2. 2. INTRODUCTION <ul><li>Limitation in training hours set by working time directives </li></ul><ul><li>Textbook and atlases present two dimensional picture of the complex neuro-anatomy </li></ul><ul><li>Training on cadavers are costly </li></ul><ul><li>Traditional apprenticeship- style of training of surgeons involve operative practise on real patients </li></ul><ul><li>Ventriculoperitoneal shunt is one of the most commonly done elective procedure </li></ul>
    3. 3. SEARCHABLE QUESTIONS <ul><li>What has been the role of virtual reality with dynamic and haptic feedback in occipital horn ventricular catheterisation for ventriculoperitoneal shunt ? </li></ul><ul><li>What are the complications reported with free hand technique of catheterisation of the ventricle and would virtual reality based training reduce such complications ? </li></ul>
    4. 4. <ul><li>SEARCH STRATEGY </li></ul><ul><li>  </li></ul><ul><li>P - Patients with hydrocephalus </li></ul><ul><li>I- virtual reality guided ventriculoperitoneal shunt </li></ul><ul><li>C- free hand ventriculoperitoneal shunt </li></ul><ul><li>O - effectiveness and reduction in complication </li></ul><ul><li>KEYWORDS </li></ul><ul><li>  SEARCH 1 - “VIRTUAL REALITY” “ NEUROSURGERY” “OCCIPITAL HORN CATHETERIZATION” </li></ul><ul><li>SEARCH 2 “ VENTRICULOPERITONEAL SHUNT” “COMPLICATIONS” </li></ul><ul><li>  </li></ul>
    5. 5. Ovid search for 1 st question
    6. 6. Scopus search for 1 st question
    7. 7. Ovid search for 2 nd question
    8. 8. Scopus search for 2 nd question
    9. 9. Search Results <ul><li>  </li></ul><ul><li>Searchable Question 1 </li></ul><ul><li>  </li></ul><ul><li>Ovid - 1 highly relavent paper </li></ul><ul><li>Scopus- further 2 highly relevant papers </li></ul><ul><li>Cochrane – no further relevant papers </li></ul><ul><li>  </li></ul><ul><li>Searchable Question 2 </li></ul><ul><li>Ovid – 1 relevant paper </li></ul><ul><li>Scopus – further 1 relevant paper. </li></ul><ul><li>Cochrane – no further relevant papers </li></ul>
    10. 10. The Relevant Papers <ul><li>Virtual reality in neurosurgical education: Part-task ventriculostomy simulation with dynamic visual and haptic feedback </li></ul><ul><li>G. Michael Jr et al, Department of Neurosurgery, University Of Illinois, Chicago, Neurosurgery, July 2007 Vo l 61: 142-149 </li></ul><ul><li>Accuracy of ventriculostomy catheter placement using a head and hand tracked high resolution virtual reality simulator with haptic feedback </li></ul><ul><li>P. Pat Banerjee et al, Department of Neurosurgery, West Virginia University, J Neurosurgery, Sept 2007 Vol 107 :515- 521 </li></ul><ul><li>  Accuracy of freehand pass technique for ventriculostomy catheter placement: Retrospective assessment using computed tomography </li></ul><ul><li>David R. Huyette et al, Department of Neurosurgery . Allegheny General Hospital Pittsburgh, J Neurosurgery, Jan 2008, Vol 108: 88-91 </li></ul><ul><li>  Medial temporal lobe epilepsy associated with misplacement of a ventricular shunting catheter </li></ul><ul><li>Kimiaki Hashiguchi et al, Department of Neurosurgery, Kyushu University, Japan, J Clinical Neuroscience, August 2008 Vol 15 :939-9942 </li></ul><ul><li>Shunt implantation: Reducing the incidence of shunt infection. </li></ul><ul><li>Choux M et al, Department of Paediatric Neurosurgery, Hospital des Enfants, France, J Neurosurgery, Dec 1977, 77 (6): </li></ul>
    11. 11. Virtual reality in neurosurgical education: Part-task ventriculostomy simulation with dynamic visual and haptic feedback G. Michael Jr et al, Department of Neurosurgery, University Of Illinois, Chicago, Neurosurgery, July 2007 Vo l 61: 142-149 <ul><li>Objective : </li></ul><ul><li>To present a system of realistic neurosurgical visual and haptic feedback simulation for neurosurgical education using ventriculostomy part-task simulation for frontal horn catheterisation </li></ul>
    12. 12. Methods: <ul><li>Immersive Touch system </li></ul><ul><li>patient CT or MRI fed to the system </li></ul><ul><li>3D virtual volume </li></ul><ul><li>The operator sits at the working table </li></ul><ul><li>stereoscopic goggles </li></ul><ul><li>A haptic stylus </li></ul><ul><li>the cut away tool ( Space Grip) </li></ul>
    13. 13. Results: <ul><li>Pre-existing scalp incision and burr hole over the Kocher’s point </li></ul><ul><li>the user sees the virtual catheter with its demarcation and positions it </li></ul><ul><li>Perpendicular trajectory </li></ul><ul><li>haptic resistance is felt like the “pop” felt during real ventricular cannulation. </li></ul><ul><li>catheter’s position is freezed using the Space Grip </li></ul><ul><li>If the catheter is within the virtual ventricle it will turn green , otherwise it will be red . </li></ul><ul><li>  </li></ul>
    14. 14. Discussion: <ul><li>textbook, atlases or computer rendering may not give full procedural knowledge and psychomotor skills </li></ul><ul><li>the cranium is fixed </li></ul><ul><li>Previously described stereoscopic virtual reality does not have haptic feedback </li></ul><ul><li>the Immersive Touch system provides realtime dynamic head tracking </li></ul>
    15. 15. Conclusion: <ul><ul><li>have produced a realistic haptic based, augmented, virtual reality simulator for neurosurgical education </li></ul></ul><ul><ul><li>accurately reproduced the experience of cannulating the ventricle. </li></ul></ul>
    16. 16. Critical Appraisal <ul><li>Did the study address the question? </li></ul><ul><li>Although the article describes a frontal horn ventriculostomy , it introduces a virtual reality system with stereoscopic and dynamic haptic feedback that could be used for occipital horn catheterisation as in a VP shunt. </li></ul>
    17. 17. <ul><li>2.Did the authors use appropriate methods to answer the question ? </li></ul><ul><li>It is a description of the development of virtual reality system with haptic feedback and serves as a proof of concept . </li></ul><ul><li>3. Were the cases recruited in acceptable way? </li></ul><ul><li>The article does not mention the number of attempts of virtual reality ventriculostomy performed. </li></ul><ul><li>  4.Were the controls selected in acceptable ways? </li></ul><ul><li>No controls. </li></ul>
    18. 18. <ul><li>5.Was the exposure accurately measured to minimise bias? </li></ul><ul><li>No mention of measurement of assessment of accuracy of the catheter placement </li></ul><ul><li>6.What confounding factors have the authors accounted for? </li></ul><ul><li>None. </li></ul><ul><li>7.What are the results of the study? </li></ul><ul><li>The authors claim that it was “universally” felt to simulate the tactile and visual components of the actual procedure of ventricular catheter insertion. </li></ul><ul><li>  </li></ul>
    19. 19. <ul><li>8.What are the drawbacks? </li></ul><ul><li>It presence as Level 4 evidence. </li></ul><ul><li>It is not a prospective randomized control study. </li></ul><ul><li>It does not mention a large number of simulations and does not describe the method of assessment . </li></ul><ul><li>The authors may also have a vested interest in the business development of the product </li></ul><ul><li>9.Can the results be applied for neurosurgical residents training for occipital horn catheterisation? </li></ul><ul><li>No - no control to compare . </li></ul><ul><li>However with further evaluation for accuracy, it may be appropriate for such training. </li></ul><ul><li>  </li></ul><ul><li>  </li></ul>
    20. 20. Accuracy of ventriculostomy catheter placement using a head and hand tracked high resolution virtual reality simulator with haptic feedback P. Pat Banerjee et al, Department of Neurosurgery, West Virginia University, J Neurosurgery, Sept 2007 Vol 107 :515- 521 <ul><li>Objective: </li></ul><ul><li>To evaluate the accuracy of ventriculostomy catheter placement on a head and hand tracked high resolution and high performance virtual reality and haptic technology workstation </li></ul>
    21. 21. Methods: <ul><li>2006 annual meeting of the AANS </li></ul><ul><li>78 fellows and residents </li></ul><ul><li>competition to perform simulated frontal ventriculostomy catheter placement </li></ul><ul><li>Immersive Touch virtual reality system </li></ul><ul><li>catheter was placed into a virtual patient’s head </li></ul><ul><li>single patient’s CT data at the University of Illinois </li></ul>
    22. 22. <ul><li>allowed one attempt each </li></ul><ul><li>right Kocher’s point </li></ul><ul><li>user freezes the virtual catheter upon feeling a successful cannulation </li></ul><ul><li>The distance from the tip of the catheter to the foramen of Monro , calculated </li></ul>
    23. 23. Results: <ul><li>The mean distance from the final position of the catheter tip to the foramen of Monro was 16.09mm (+/- 9.6 mm) in 78 trials </li></ul><ul><li>73% successfully reached the ventricles </li></ul><ul><li>27% were unsuccessful </li></ul><ul><li>Of the successful ones, 38.5% reached the anterior horn of the right ventricle </li></ul><ul><li>no strong correlation between the level of training and performance </li></ul>
    24. 24. Discusssion: <ul><li>similar to a retrospective study in 2007 by Huyette et al </li></ul><ul><li>97 patients who underwent 98 freehand cannulation with a success rate of 79% </li></ul><ul><li>distance of 16 mm of the catheter tip from the foramen of Monro </li></ul>
    25. 25. Conclusion: <ul><li>The virtual reality system accurately reproduces the part task experience of ventriculostomy </li></ul>
    26. 26. Critical Appraisal <ul><li>1.Did the study address the question? </li></ul><ul><li>Yes. Although the article describes a frontal horn ventriculostomy , it introduces a virtual reality system with stereoscopic and dynamic haptic feedback that could be used for occipital horn catheterisation as in a VP shunt . </li></ul>
    27. 27. <ul><li>2.Did the authors use appropriate methods to answer the question? </li></ul><ul><li>Yes. The study was conducted on 78 fellows and residents in training who were allowed to perform a single attempt cannulation using the Immersive Touch virtual reality system for the first time. </li></ul><ul><li>3.Were the cases recruited in acceptable way? </li></ul><ul><li>The 78 fellows and residents suited the criteria for the educational task and all were told of the competition only at the meeting. </li></ul>
    28. 28. <ul><li>4.Were the controls selected in acceptable ways ? </li></ul><ul><li>The control mentioned in the discussion was from a separate retrospective study done previously by Huyette et al on 97 real patients. Ideally, it should have a prospective arm of actual ventriculostomy with similar number and similar set of participants. </li></ul><ul><li>5.Was the exposure accurately measured to minimise bias? </li></ul><ul><li>Yes. The final catheter tip position and orientation was recorded in the computer and measurements were objectively based on the recording. </li></ul>
    29. 29. <ul><li>6. What confounding factors have the authors accounted for? </li></ul><ul><li>Years of training was compared with the results. </li></ul><ul><li>7. What are the results of the study? </li></ul><ul><li>73% of the catheter tip successfully reached the ventricles. </li></ul><ul><li>27% were extra ventricular. 38% were in the anterior horn of the ipsilateral ventricles. The mean distance of the final position of the catheter tip was 16.09 mm +/- 7.85mm . </li></ul><ul><li>In comparison with the free hand cannulation based on the mentioned retrospective study, virtual reality provided similar results , signifying that virtual reality could create a model that is similar to actual cannulation. </li></ul>
    30. 30. <ul><li>8. Do I believe the results? </li></ul><ul><li>Yes. Although it is of Level 3 Evidence, the trial in the form of a competition was done at a AANS annual meeting. </li></ul><ul><li>9. Can the results be applied to neurosurgical residents training for occipital horn catheterisation ? </li></ul><ul><li>Though this study is of frontal horn ventriculostomy, as the subjects tested were similar to those for whom the educational task were intended, this study is relevant and applicable. </li></ul><ul><li>  </li></ul>
    31. 31. Accuracy of freehand pass technique for ventriculostomy catheter placement: Retrospective assessment using computed tomography David R. Huyette et al, Department of Neurosurgery . Allegheny General Hospital Pittsburgh, J Neurosurgery, Jan 2008, Vol 108: 88-91 <ul><li>Objective: </li></ul><ul><li>To determine the accuracy of successful frontal ventriculostomy performed at a single institution’s intensive care unit and that use of surface landmark may not correlate with desirable catheter tip placement </li></ul>
    32. 32. Methods: <ul><li>Retrospective evaluation of CT scans </li></ul><ul><li>97 patients who underwent 98 freehand pass ventriculostomy </li></ul><ul><li>January 2001 to December 2004 </li></ul><ul><li>The Kocher’s point on the right side </li></ul><ul><li>Using postoperative CT scans, 3D measurements </li></ul><ul><li>Single investigator </li></ul>
    33. 33. Results: <ul><li>The mean distance from catheter tip to the foramen of Monro was 16 +/- 9.6 mm </li></ul><ul><li>77.6% were intraventricular </li></ul><ul><li>56.1% of the catheter tip were in the ipsilateral ventricle </li></ul><ul><li>only 29 procedural notes described the number of passes which averaged 2.17 </li></ul><ul><li>18% of the CT scans showed haemorrhage around the path of the catheter </li></ul>
    34. 34. Discussion: <ul><li>freehand ventriculostomy catheterisation is suboptimal </li></ul><ul><li>requiring 2 passes per successful placement </li></ul><ul><li>prompting to ask whether there are better way to perform ventriculostomy </li></ul>
    35. 35. Critical Appraisal <ul><li>1.Did the study address the question? </li></ul><ul><li>The study addressed the free hand pass technique part of the question. </li></ul><ul><li>2.Did the authors use appropriate methods to answer the question? </li></ul><ul><li>This is a retrospective study in a single institution. A prospective multi centre study would be more appropriate. </li></ul>
    36. 36. <ul><li>3.Were the cases recruited in acceptable way? </li></ul><ul><li>For a retrospective study, it was appropriately selected. The CT scans for consecutive ventriculostomies were studied, excluding those with poor image quality </li></ul><ul><li>4.Were the controls selected in acceptable ways? </li></ul><ul><li>There was no controls. </li></ul><ul><li>5.Was the exposure accurately measured to minimise bias? </li></ul><ul><li>No. The assessment of the position of the tip of the catheter and its measurement from the foramen of Monro was made by a single investigator who is the primary author </li></ul>
    37. 37. <ul><li>6. What confounding factors have the authors accounted for? </li></ul><ul><li>i) CT scans with poor image quality were excluded </li></ul><ul><li>ii) the degree of hydrocephalus </li></ul><ul><li>7.What are the results of the study? </li></ul><ul><li>77.6% were within intraventricular </li></ul><ul><li>22.4% of them were extraventricular. </li></ul><ul><li>The mean distance of the catheter tip from the foramen of Monro was 16 +/- 9.8 mm. </li></ul><ul><li>The average number of passes were 2.17 </li></ul><ul><li>18% haemorrhage </li></ul><ul><li>  </li></ul>
    38. 38. <ul><li>The flaws in the study are : </li></ul><ul><li>It is retrospective </li></ul><ul><li>investigator – primary author/ not blinded </li></ul><ul><li>Only 29 of the procedural/operative notes mention the number of passes attempted for the ventriculostomy, therefore the true average of the number of passes required cannot be accurately determined </li></ul><ul><li>The catheter tip in the interhemispheric fissure were not included as in the extra ventricular space. </li></ul>
    39. 39. <ul><li>Can the results be applied to favour neurosurgical residents training for occipital horn catheterisation with virtual reality? </li></ul><ul><li>Though there are flaws to the study, since this is the only study on free hand pass technique on ventriculostomy and it states that an average of 2.17 passes are required, it may be appropriate that a prospective randomized trial comparing free hand technique with virtual reality trained residents ventriculostomies be initiated </li></ul>
    40. 40. Medial temporal lobe epilepsy associated with misplacement of a ventricular shunting catheter Kimiaki Hashiguchi et al, Department of Neurosurgery, Kyushu University, Japan, J Clinical Neuroscience, August 2008 Vol 15 :939-9942   <ul><li>a 35 year old woman, childhood cerebellar astrocytoma </li></ul><ul><li>developed right medial temporal lobe epilepsy </li></ul><ul><li>misplacement of a ventricular shunting catheter in the apex of the right temporal lobe </li></ul><ul><li>Electrocardiography showed frequent activity at the right hippocampus </li></ul><ul><li>Hippocampectomy and removal of the shunt </li></ul><ul><li>presence of foreign material within the brain parenchyma could have caused epileptogenic hippocampal sclerosis. </li></ul>
    41. 41. CRITICAL APPRAISAL <ul><li>Level 4 Evidence </li></ul><ul><li>a single patient </li></ul><ul><li>mentions that there were 3 other previous reports on formation of epileptogenic focus </li></ul><ul><li>does not give the quantification of the risk of epilepsy in catheter misplacement </li></ul>
    42. 42. Shunt implantation: Reducing the incidence of shunt infection . Choux M et al, Department of Paediatric Neurosurgery, Hospital des Enfants, France, J Neurosurgery, Dec 1992, 77 (6): 875-80 <ul><li>Objective: </li></ul><ul><li>5 to 15% shunt becomes infected </li></ul><ul><li>To see whether shunt infection is preventable with meticulous surgical technique. </li></ul>
    43. 43. Methods: <ul><li>The authors review their experience with two time periods </li></ul><ul><li>1) January 1978 to December, 1982 </li></ul><ul><li>302 children with hydrocephalus underwent 606 operations </li></ul><ul><li>retrospective analysis </li></ul><ul><li>2) Jan 1983 and and December 1990 </li></ul><ul><li>600 children underwent 1197 shunt insertion </li></ul><ul><li>new protocol of shunt insertion </li></ul><ul><li>prospective analysis </li></ul>
    44. 44. <ul><li>each procedure was not more than 20 to 40 minutes </li></ul><ul><li>carried out by an experience neurosurgeon </li></ul><ul><li>Intra-operative CSF was sent for culture </li></ul><ul><li>A postoperative shunt infection was defined as infection confirmed within 6 months of shunt insertion </li></ul>
    45. 45. Results: <ul><li>For the first group : infection rate of 15.6% </li></ul><ul><li>In the second group : infection was 0.33% </li></ul>
    46. 46. Discussion <ul><li>meticulous surgical technique reduce significantly the incidence of shunt infection </li></ul><ul><li>authors believe that the experience of the surgeon as one of the most important factor </li></ul>
    47. 47. Critical Appraisal <ul><li>1.Did the study address the question? </li></ul><ul><li>The study addressed the infective complications of the second question </li></ul><ul><li>2.Did the authors use appropriate methods to study the question? </li></ul><ul><li>This is a pseudo-randomized trial as the first group was retrospectively studied while the second group was prospectively studied. It will be difficult to get patients to prospectively enrol for a less meticulously performed surgery. In my opinion, it was an appropriate method </li></ul>
    48. 48. <ul><li>3.Were the cases recruited in acceptable way? </li></ul><ul><li>Yes. All consecutive patients for the study period with hydrocephalus underwent ventriculoperitoneal shunting were recruited and had been followed up for a minimum period of 6 months. </li></ul><ul><li>  </li></ul><ul><li>4.Were the controls selected in acceptable ways? </li></ul><ul><li>The cases for the retrospective group, used as control, were acceptably recruited as all consecutive patients for the study period with hydrocephalus undergoing primary and revision surgery were included and followed up between 6 months to 8 years . </li></ul>
    49. 49. <ul><li>5.Was the exposure accurately measured to minimise bias ? </li></ul><ul><li>Yes. All patients with clinical infection had positive culture </li></ul><ul><li>6.What confounding factors have the authors accounted for? </li></ul><ul><li>1) Shunt insertion was deferred in cases of intercurrent illness/ local skin infection. </li></ul><ul><li>2) However, the detailed account of the etiological factors for the hydrocephalus for comparison between the groups was not given. In cases of myelomeningoceles with hydrocephalus the infection risk may be higher. </li></ul><ul><li>  </li></ul>
    50. 50. <ul><li>7.What are the results of the study? </li></ul><ul><li>The incidence of shunt infection reduced dramatically from 15.6% to 0.33% with meticulous operative protocol. </li></ul><ul><li>8. Do I believe the results? </li></ul><ul><li>Yes. </li></ul><ul><li>Level 3 </li></ul><ul><li>Frequently cited </li></ul><ul><li>No significant bias </li></ul>
    51. 51. <ul><li>SUMMARY </li></ul><ul><li>Virtual reality with visual and haptic feedback </li></ul><ul><li>available </li></ul><ul><li>Can be used for ventriculostomy for VP shunt </li></ul><ul><li>Comparable with free hand technique </li></ul><ul><li>Learn skill without danger to patient </li></ul>

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