Patient-specific planning and 3D technology in H&N reconstruction

Professor Panayiotis Kyzas

PhD, FRCS (OMFS)

Consultant OMFS H&N Surgeon

Royal Blackburn Teaching Hospital / East Lancashire Hospitals Trust

BJOMS

Royal Blackburn Teaching Hospital

Edge Hill University

NIHR grant (NIHR152682) MANTRA trial

MANdibular TRauma and Antibiotics

Topics

Introduction

Principles of reconstructive surgery

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• Restore “like for like”
• Aim for excellent “function and cosmesis”

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• Minimize morbidity – keep it simple

Introduction

Challenges in H&N reconstruction

• Multiple unique complex functions
• Speech
• Mastication
• Swallowing
• Smiling, kissing, facial expression
• Dentition, occlusion
• Aesthetics
• Symmetry
• Skin color and texture
• Face is the “mirror of the soul”

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Introduction

Gold standard for BONE H&N reconstruction

Microvascular free tissue transfer

• Fibula
• DCIA
• Scapula

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Other (not recommended) methods

• Bone grafts
• Titanium implants
• Plate + soft tissue flap

Introduction-History�The past (I hope…)

Introduction – The past

“Long‐term functional and aesthetic outcomes after fibula free flap reconstruction of the mandible”

Head & Neck Volume41, Issue7;July 2019; Pages 2123-2132

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• Clinicians report 65% functional and cosmetic satisfaction…

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• Patients don’t…

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Introduction

Principles of reconstructive surgery

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• Do not compromise
• Do not cut corners
• Continuously improve

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Introduction

Introduction – A history of meaningful innovations

• 1990 – First ever 3D printing Wilfried Vancraen, Germany
• 1992 – Mapping the Anatomy in 3D, healthcare – Fried
• 1993 – Software to link CT – 3D printing
• 1995 – Stereolithography
• 1996 – Orthodontic 3D guides
• 2000 – 3D printers industrialise – size of rooms or bigger…
• 2004 – Software editing of STL files
• 2006 – Titanium 3D printed skull implants
• 2007 – Personalized knee surgery guides

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Introduction – A history of meaningful innovations

• 2008 – Personalized hip surgery guides
• 2010 – Fashion, 3D printed dresses

– first facial transplant

• 2011 – linking computer to 3D printer
• 2012 – 3D guides for tumour resection/H&N free flap reconstruction PSP

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• 2013 – My first ever 3D planned case (anterior mandible – DCIA)
• 2012-2019 – industry, healthcare, software continuous improvement
• 2019 – first ever attempt of 3D soft tissue reconstruction planning in H&N
• 2020 – covid19…

A history of meaningful innovations

PSP in daily H&N practice

The epitome of teamwork

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• Clinicians – ideas, medical know-how, execution
• Reconstructive scientists – software use, guides design
• Machines – accuracy, resilience, time management
• Students / Junior doctors – education & training
• Theatre nurses – better understanding and involvement
• Managers – cost-effectiveness
• Public – innovation & excitement
• Patients – better understanding – consent, QoL

PSP in daily H&N practice

My declaration

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• I am a surgeon
• I have used this for hundreds of cases
• I still think it’s done by magic
• It’s fascinating
• I don’t understand the details of the software
• I admire the reconstructive scientists

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I CANNOT DO THIS ALONE

PSP in daily H&N practice

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An idiot’s guide to PSP – 3D in H&N ablation and reconstruction

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• Patient has fine-cut CT scan (H&N + donor) < 0.5mm
• Scan images/files uploaded transformed into the appropriate software format
• Planning session
• Surgeon plans resection of the tumor
• Reconstructive scientist designs resection guides
• Surgeon plans reconstruction
• Reconstructive scientist designs flap harvesting guides
• Plate design – milled
• Surgery

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PSP in daily H&N practice – example (simple)

PSP in daily H&N practice – example (simple)

PSP in daily H&N practice – example (simple)

PSP in daily H&N practice – example (even simpler)

PSP in daily H&N practice – example (even simpler)

PSP in daily H&N practice – example (even simpler)

PSP in daily H&N practice

Potential gains / advantages

• Reduce operating time
• Accurate results
• Education & Training
• Unit Kudos / Publicity
• Aids dental rehabilitation ?
• R0 resections?
• Free flap success rate? Minimizes ischemia time
• Standardization

PSP in daily H&N practice

Potential pitfalls

• Surgeon no longer an artist…
• Guides’ error margin minimal
• Vertical rotation difficult to control
• Advancing cancers…
• Time to produce
• Cost
• Learning curve

PSP in daily H&N practice

Planning tips

• Respect ablation principles!!!!!

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• DO NOT compromise on margins

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• DO NOT think reconstruction when planning resection

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• Use imaging aided by clinical examination

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PSP in daily H&N practice – example of soft tissue

Osteoradionecrosis (ORN) – beware of the soft tissue element

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Scarring….

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Condylar head positioning…

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Old metal work…

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Example

Refuted myths

Myth: PSP is so rare that TV and press should cover every case

Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

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• Accurate soft tissue reconstruction is extremely important

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• Studies from breast reconstructive surgery highlight the importance of
• VOLUME
• OUTLINE (perimeter)

Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

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Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

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• A 3D matrix can be designed as a soft tissue free flap harvest guide

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• Utilised routinely in breast surgery

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• Can this be used in H&N reconstructive surgery?

Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

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Challenges in H&N

• Very complex anatomy (i.e., oropharynx)
• Volume defect difficult to accurately predict
• Soft tissue flaps often designed to “plug a hole”

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• Custom designs not suitable for every case (PERSONALISED)

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Pushing the boundaries

Myth 7: PSP and 3D printing only applies to bony reconstruction

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Examples of custom soft tissue H&N designs

Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

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Examples of custom soft tissue H&N designs

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The problem:

• Relying on artistic, imaginary estimates
• Because of that, initial acceptable results have no longevity

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• Aim for ACCURACY

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Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

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Why not implement the 3D / PSP principles in soft tissue H&N reconstruction?

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Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

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Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

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Introducing the PANSOFOS flap

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Personalised pAtient-specific plaNning of SOFt tissue reconstruction

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PANSOFOS in Greek means “the one who is extremely wise”

Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

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Introducing the PANSOFOS flap / Aims

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1. Accurately use pre-operative resection plan to copy the excised soft tissue (scan)
2. Produce a negative analogue/mould/matrix of the excised soft tissue
3. Use the above matrix to design the shape and adjust the volume of the harvested free flap
4. Record theatre time, surgical complications and hospital stay
5. Record swallowing outcomes (function)

Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

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Introducing the PANSOFOS flap

Use of the IDEAL framework to report surgical innovations – Improving the quality of research in surgery

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 www.ideal-collaboration.net  

Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

PANSOFOS flap

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Case description

78-year-old cT3N0M0 right oral tongue SCC (AJCC 8^th)

Planned for radical surgery / curative intent

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Resection planned on staging scans

DICOM files transformed into SLT 3D models

Selected flap RFFF

Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

PANSOFOS flap

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Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

PANSOFOS flap

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3D resection guide / negative silicone mould

Silicone: elastic material/ability to change shape and return to the original

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Transformation of the 3D defect (and the subsequent reconstructive target) into a 2D flattened flap shape and perimeter

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The mould also acts as a volumetric guide for the flap.

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Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

PANSOFOS flap

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Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

PANSOFOS flap

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Uncomplicated surgery – Successful free flap

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Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

PANSOFOS flap

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Initially thought flap was too big

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But SALT assessment and functional outcome PERFECT

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R0 resection margins

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Cure and QoL

Pushing the boundaries

Myth: PSP and 3D printing only applies to bony reconstruction

PANSOFOS flap

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Conclusion

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PANSOFOS design crucial for large volume defects (i.e., total glossectomy) OR complex 2D perimeter defects (soft palate – oropharynx)

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The future

• Proper health economy calculations
• Surgical time
• Theatre utilisation
• 3D printer – guides cost
• Hospital stay
• Return to theatre
• Complications
• Need for RIG/PEG
• Dental Implant utilisation
• Metal work (plate) removals
• Long term follow up outcomes

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The future

• Continue to work on 3D/PSP accuracy
• Guides fitting
• Communication, feedback, incident reporting
• Vertical orientation of bony flaps
• Dental implant emergence
• Immediate flap implant loading
• Standardisation of guides and software

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The future

• Continue to explore soft tissue H&N reconstruction
• IDEAL stage 2 (more patients, health economics)
• Application to more complex defects
• Adjust ZIP flap into a 3D/PSP/ZIP

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• Real time guides?

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• Virtual reality?

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• Simplified software?

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Questions ?

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Thanks for listening

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+44(0)7505402640

Panayiotis.Kyzas@elht.nhs.uk

kyzasp@icloud.com