Types of Neck Dissection and the Post-Operative Neck

Daniel W. Williams III, MD

Outline

I.  Primary site II.  Neck dissections III.  Myocutaneous flaps

1° Site Imaging Appearance

Conventional Open Surgery TORS*

(TransOral Robotic Surgery)

* Photos courtesy of Josh Waltonen MD

1° Site Imaging Appearance: Conventional Open Surgery

•  Tumor (+ adjacent tissue) resected •  Anatomic distortion •  Enhancing granulation tissue (early) or scar

(later)

Post-op

Total Laryngectomy (Larynx SCCa)

Pre-op Pre-op Post-op

Parotidectomy (Mucoepidermoid Ca)

1° Site Imaging Appearance: TORS

•  Depends on type of surgery (lat oropharyngectomy, PSGL, BOT resection etc…)

•  Tumor resected (usually minimal margin) •  Progressive retraction of lat. OP wall or BOT •  Loss of fat planes around medial pterygoid muscle

and pterygomandibular raphe

“Transoral Robotic Surgery in Head and Neck Cancer: What Radiologists Need to Know about the Cutting Edge”, LALoevner MD et al, RadioGraphics 2013; 33:1759–1779

62 F, left tonsil SCCa s/p TORS (Radical Tonsillectomy)

Pre-op Post-op

88M, right BOT SCCA s/p TORS

Post-op 2015 Pre-op 2011

Outline

I.  Primary site II.  Neck dissections III.  Myocutaneous flaps

Neck Dissection •  Systematic removal of LN’s and

surrounding fibrofatty tissue from various compartments of the neck (cervical lymphadenectomy)

•  Types

– Therapeutic: positive nodes by exam – Elective: suspected occult nodes

ND Rationale

•  Each anatomic site has its own nodal spread pattern, and…

•  Nodal involvement is (usually) orderly and predictable, and…

•  Removing nodes involved or at risk improves loco-regional control and patient outcomes

•  Grandfather of ND in N. America •  Published a systematic approach to ND in 1905 •  Cleveland Clinic founder

General George W. Crile Sr.

1864-1943 Crile building at Cleveland Clinic

Neck Dissection Classification *

1.  Radical neck dissection (RND) 2.  Modified RND 3.  Selective ND (“SND”+ LN levels

removed) 4.  Extended ND (RND plus) * KT Robbins et al. Neck dissection classification update. Arch Otolaryn Head Neck Surg 2002; 128: 751-758.

Radical Neck Dissection Structures removed

- LN levels I-V - SCM, IJV, SAN - SM gland

Standard procedure to which other ND’s compared

Cummings, 4th ed. 2005

Normal RND

Radical Neck Dissection Modified RND Structures removed - LN levels I-V

Structures preserved - 1 or more non- lymphatic structures (SCM, IJV, SAN) c/w RND

Cummings, 4th ed. 2005

Modified RND

IJV + SAN SCM + IJV SCM + SAN

Normal Modified RND

Modified RND (IJV & SCM removed)

Modified RND (Bilateral; SCM removed)

Selective Neck Dissection Preservation of 1 or more LN levels

(c/w RND): -  Oral cavity: SND (I-III) -  OP/HP & laryngeal: SND (II-IV) -  Low ant. neck ML structures: SND (VI) - Skin Ca: SND (LN levels adj. to 1°)

SND for Oral Cavity Ca SND (I-III) *

Structures removed - LN levels I, II, III - SM gland

* Supraomohyoid SND

Normal SND Selective ND (I-III)

Imaging Appearance of ND’s •  Depends on type of surgery •  RND/some MRND’s: recognizable Δ’s

– absent structures, neck contour Δ, muscle denerv atrophy / hypertrophy

•  Some MRND/most SND’s: subtle Δ’s –  loss of fat planes, slight neck contour Δ,

surgical scar, ± absent structures

•  Be alert for complications and pitfalls

Recognizing Neck Dissections

•  Use neck symmetry! •  Neck contour abnormality/scar? •  SCM, IJV present? •  Trapezius m. atrophy? •  Fat planes around IJV/CA?

Read the Op Note!

Complications and Pitfalls

•  Complications –  Perioperative - bleeding, nerve injury, pntx, air

embolus/leak, infection/abscess –  Postoperative – shoulder syndrome, fistulas,

CA rupture, IJV thrombosis, facial/cerebral edema, traumatic neuroma

•  Pitfalls –  MC flaps –  Pseudotumors –  IJV stump

Complications and Pitfalls

Neck abscess Pseudotumor (lev. scap. hypertrophy)

Outline

I.  Primary site II.  Neck dissections III.  Myocutaneous flaps

Options in Head and Neck Reconstruction

•  Healing by secondary intention •  Primary closure •  Skin grafts (split or full thickness) •  Composite grafts •  Flaps (local, distant pedicled, distant

free)

From Gurtner GC, Evans GR. Advances in head and neck reconstruction. Plast Reconstr Surg 2000;106:672-682; quiz 683

MC Flaps: Uses •  Facilitate wound closure •  Repair surgical defects •  Enables more complete removal of 1° tumor •  Restore optimal function (speech, breathing,

mastication, swallowing) •  Cosmesis (recreation of facial aesthetics) •  Protection (carotid artery during RT, skull

base, orbital apex)

MC Flaps: Classification

Flaps classified according to: • Blood supply (random, axial, free) • Type of tissue transferred (cutaneous,

myocutaneous, osteomyocutaneous) • Site of origin (local, regional,

microvascular free tissue transfer) • Flat vs. tubed

Rec. larynx ca w/ carotid invasion

Case: Regional flap (pectoralis major)

Thanks to D. Browne, MD

Carotid artery sacrificed

Saphenous vein graft

Harvested flap PM flap in place

SCCA alveolar ridge

Case: Free flap (iliac crest)

Thanks to D. Browne, MD

Skin paddle Surgical landmark

Harvested flap

Iliac crest flap; Titanium bar

Post-op

MC Flaps: Imaging Appearance

•  Imaging changes usually obvious, but can be quite subtle

•  Pearls: – Compare to pre-treatment exam – Read the op-note or call the surgeon !!!! – Be aware of potential complications and

pitfalls

MC Flaps: CT/MR findings

•  Neck contour change •  Fatty “mass” w/ muscle striations •  Muscle denervation atrophy over time •  Muscle enhancement on MR (often

intense, persists many months) •  Rotational flaps - muscle origin remains

attached; vascular pedicle visible •  “Unusual appearing” bones/other signs of

surgery

Scapular free flap

Neck contour change; fatty “mass” (rec. OC Ca)

Fatty “mass”; muscle striations (larynx Ca)

Pre-op Post-op

Laryngectomy + tubed PM flap

Muscle atrophy over time (maxillary sinus Ca)

Maxillectomy + temporalis flap 2003 2007

Enhancing muscle component (tonsil SCCA)

T1 pre-Gd

T1+Gd+FS

Tonsillectomy + pectoralis major flap

Muscle origin remains attached

Pectoralis major flap

Chest wall changes; Vascular pedicle

Pectoralis major flap (+ RND)

Scapular OMC free flap (s/p maxillectomy)

“Unusual appearing” bones + hardware Other signs of surgery

Temporalis flap

Zygomatic arch plate

MEDPOR® implant

Complications and Pitfalls •  Fluid collections, fistulas, IJV thrombosis,

flap ischemia/necrosis, nerve injury, bone nonunion or infection

•  Pseudotumors (muscle denerv. atrophy, muscle hypertrophy, enhancing flap muscle component)

•  Changes or complications assoc. with primary tumor excision, ND or RT

•  Hide early tumor recurrences from PEx

s/p resection inverted papilloma

Complication: Temporalis flap necrosis + Abscess

Pitfall: CN 12 injury (tongue denerv. atrophy)

Conclusions •  Perform high quality exams •  Learn types of ND’s and MCF’s used at your

institution •  Recognizing post-Rx changes will help

detect recurrent H/N Ca and avoid imaging exam misinterpretation

•  Above all, read Rx notes/speak to the surgeon and/or radiation oncologist

The End