Development of a Deep Vein Valve Replacement Thesis submitted to Imperial College London for the degree of Doctor of Philosophy Miss Hayley Moore MA (Cantab), MBBS (AICSM), MRCS (Eng) Registration 1st October 2010 Supervisors Professor Alun H Davies (Vascular Surgery) Professor Molly Stevens (Biomedical Materials) Professor Yun Xu (Biofluid Mechanics) Mr Manj Gohel (Vascular Surgery) 1 CONTENTS Contents ........................................................................................................................................................................ 2 Abstract ......................................................................................................................................................................... 8 Acknowledgements .................................................................................................................................................... 10 Statement of Originality ............................................................................................................................................ 11 List of Tables .............................................................................................................................................................. 12 List of Figures ............................................................................................................................................................. 14 Abbreviations.............................................................................................................................................................. 22 1. Introduction ....................................................................................................................................................... 26 1.1 Background ............................................................................................................................................... 26 1.2 The Aetiology of deep venous disease ................................................................................................. 27 1.2.1 Anatomical locations of deep venous obstruction .................................................................... 29 1.2.2 Anatomical locations of deep venous reflux .............................................................................. 34 1.3 Post-thrombotic syndrome .................................................................................................................... 42 2. Aims .................................................................................................................................................................... 61 3. Deep venous disease ........................................................................................................................................ 63 3.1 Current Treatment options for Patients with Deep venous Disease .............................................. 63 3.2 Implantable Venous Valves for Deep Venous Insufficiency – the Story so Far .......................... 72 4. The Anatomy of Deep Vein Valves .............................................................................................................. 91 2 4.1 Review of the Literature ......................................................................................................................... 91 4.1.1 Introduction .................................................................................................................................... 91 4.1.2 Methods ........................................................................................................................................... 91 4.1.3 Results .............................................................................................................................................. 92 4.1.4 Discussion........................................................................................................................................ 96 5. Damaged venous valves ................................................................................................................................... 99 5.1 A Survey on the management of patients with complex venous reflux and obstruction ............ 99 5.1.1 Introduction .................................................................................................................................... 99 5.1.2 Methods ......................................................................................................................................... 100 5.1.3 Results ............................................................................................................................................ 100 5.1.4 Discussion...................................................................................................................................... 118 6. Imaging the Venous System to Develop A Computational Model of A Deep Vein Valve ............... 119 6.1 Introduction............................................................................................................................................ 119 6.1.1 Venous Haemodynamics ............................................................................................................. 119 6.1.2 Flow Direction .............................................................................................................................. 120 6.1.3 Venous Pressure (Normal, supine, stationary, walking) ......................................................... 124 6.2 Imaging in Venous Disease .................................................................................................................. 136 6.2.1 Introduction .................................................................................................................................. 136 6.2.2 Ultrasound ..................................................................................................................................... 136 6.2.3 Laser Doppler ............................................................................................................................... 145 3 6.2.4 Plethysmography .......................................................................................................................... 145 6.2.5 Venography ................................................................................................................................... 147 6.2.6 Intravascular Ultrasound (IVUS) ............................................................................................... 149 6.2.7 Computed Tomography Venography (CTV) .......................................................................... 150 6.2.8 Magnetic Resonance Venography (MRV) ................................................................................ 151 6.2.9 Image Guidance for venous interventions ............................................................................... 154 6.2.10 Venous Malformations ................................................................................................................ 155 6.2.11 Other techniques .......................................................................................................................... 155 6.3 Ultrasound Imaging of Deep Vein Valves ........................................................................................ 155 6.3.1 Background ................................................................................................................................... 155 6.3.2 Methods ......................................................................................................................................... 156 6.3.3 Results ............................................................................................................................................ 160 6.3.4 Discussion...................................................................................................................................... 169 6.4 Magnetic Resonance Imaging of Deep Vein Valves ........................................................................ 169 6.4.1 Introduction .................................................................................................................................. 169 6.4.2 Methods ......................................................................................................................................... 170 6.4.3 Results ............................................................................................................................................ 175 6.4.4 Discussion...................................................................................................................................... 178 6.5 Computational Modelling of Deep Vein Valves .............................................................................. 179 6.5.1 Introduction .................................................................................................................................. 179 4 6.5.2 Methods ......................................................................................................................................... 181 6.5.3 Results ............................................................................................................................................ 185 6.5.4 Discussion...................................................................................................................................... 195 7. Development of a Novel Material