KEY NOTES CHAPTER 4: BREAST AND CHEST WALL - Chest Wall Reconstruction. Flashcards
What are pectus deformities?
• ~1 in 300 live births
• Result from rib cage overgrowth ->
∘ Pectus excavatum (concave chest).
∘ Pectus carinatum (convex or pigeon chest).
What are the indications for chest wall reconstruction?
∘ Tumour resection
∘ Infection
∘ Radiation injury
∘ Trauma.
What is pectus excavatum?
- Most common congenital chest wall anomaly.
- Sternum displaced posteriorly
- M:F = 3:1.
- Associated with scoliosis and Marfan’s syndrome, pulmonary or cardiac compromise (surgery may improve ejection fraction but not lung function).
• Surgery:
∘ Ribcage reconstruction.
∘ Insertion of a prosthetic moulage.
What types of pectus excavatum reconstuction do you know of?
• Nuss repair (1988)
1. Small incisions in lateral chest wall.
2 A shaped convex metal bar is inserted subcutaneously up to sternum, then retrosternally (under video thoracoscopic guidance), then re-enters subcutaneous plane
3. Bar is flipped over
∘ Results in sternal elevation with subsequent remodelling of ribs and costal cartilages.
∘ Not effective in adults
• Ravitch procedure (1949)
• Sternal turnover
Custom-made prosthesis (subcut).
.
2500 live births; M:F = 4:1.
∘ Non-operative management with a brace.
- Worn 14 hours a day for 2 years; provides continuous AP compression.
- Progressively remodels chest.
∘ Operative management by modifications of the Ravitch or Nuss procedure.
What is Poland’s syndrome?
Alfred Poland (1841) anatomy demonstrating at Guy’s Hospital originally described:
- absent sternocostal pectoralis major (intact clavicular origin),
- absence of pectoralis minor,
- hypoplastic serratus anterior and external oblique.
What are the clinical features?
Characterised by unilateral chest wall and upper limb abnormalities.
• Variable manifestation
• 1 in 30,000, usually sporadic.
• M:F 3:1
• R>L
• ? developmental anomaly of subclavian artery in 6th week.
• Associated with Möbius and Klippel-Feil syndromes.
What are the chest wall and upper limb abnormalities?
Chest wall
• Absent sternocostal head of pectoralis major
• Absent / hypoplastic breast and NAC (displaced superiorly).
• Lack of subcutaneous fat and axillary hair.
• Abnormalities of pectoralis minor, infraspinatus, supraspinatus, LD, serratus anterior, external oblique and rectus abdominis.
• Abnormalities of rib cage +/- lung herniation.
Upper limb
• Short arms
• Brachysyndactyly.
How is breast asymmetry treated?
• Adolescents: tissue expander/implant.
Female
• Once breast development is complete, expander can be replaced with:
1. Definitive implant covered + LD flap or ADM.
2. Autologous tissue:
- Pedicled ipsilateral LD or free contralateral LD.
- TRAM/DIEP flap.
- Lipomodelling.
Male
• LD: recreate anterior axillary fold and mask infraclavicular hollow.
∘ humeral insertion is detached and sutured more
anteriorly on bicipital groove.
• Contralateral costal grafts for absent ribs.
• Custom made subcutaneous silicone implant
What are the risk factors for sternal wound infection?
1 Superficial infection: skin, subcutaneous tissue and pectoralis fascia.
∘ systemic antibiotics.
2 Deep infection = mediastinitis
1-5% of median sternotomies.
∘ aggressive surgical debridement and flap coverage.
• Risk factors: ∘ Diabetes ∘ Obesity ∘ COPD ∘ Osteoporosis ∘ Smoking ∘ Use of bilateral internal mammary arteries ∘ Revision operations ∘ Prolonged ITU
How is sternal infection classified?
Pairolero
Type I
∘ ~1 week after sternotomy.
∘ Serosanguinous discharge no cellulitis, costochondritis
or osteomyelitis.
- iv antibiotics +/- single-stage operation.
• Type II
∘ 2-4wks
∘ Purulent mediastinitis, osteomyelitis ± costochondritis.
- Debridement, removal of FBs. Dead space obliteration with soft tissue flap.
• Type III
∘ months to years
∘ chronic sinus, costochondritis, osteomyelitis, retained FBs.
- Repeated debridements + flaps.
What are the indications for definitive surgical treatment?
Factors predicting need for surgical intervention: ∘ Bacteraemia ∘ Wound depth >4 cm ∘ Bone exposure ∘ Sternal instability.
What is a good adjunct to surgical debridement?
NPWT ∘ Increased local blood flow. ∘ Decreased bacterial count. ∘ Enhanced granulation tissue formation. ∘ Chest stabilisation and improved respiratory function.
What is the treatment for types 2 & 3 sternal infections?
Surgical debridement
Remove sternal wires
Micro samples
Dead space management:
- Pectoralis major flap.
- Turnover: IMA perforators.
- Rotation advancement: pectoral branches of TA axis, +/- ant rectus sheath to cover inferior sternum. - Rectus abdominis flap (muscle / myocutaneous).
• Supplied by superior epigastric artery (may be compromised if IMA’s used for CABG) or 8th intercostal artery. - Omental flap + SSG.
• Based on either gastro-epiploic pedicles.
When is chest wall reconstruction indicated after tumour ablation or trauma?
- chest wall defects >5 cm, or
- segmental loss of four contiguous ribs
Need to consider skeletal support and soft tissue cover.
What can be used for skeletal support?
Autologous tissue
• Split rib grafts
• Iliac crest
• Fibula.
- Alloplastic materials
∘ Induces fibrovascular infiltration with incorporation into surrounding tissues.
Mesh and composite implants
(a) Polypropylene knitted mesh (permanent).
- Marlex®: Single-knit (expandable in one direction, rigid in another).
- Prolene®: Double-knit (expandable in both directions).
(b) Polyester: Mersilene®, Dacron®.
(c) Polyglycolic acid: Dexon®.
(d) Expanded polytetrafluoroethylene (e-PTFE): Gore-Tex®.
(e) Polydioxanone: PDS®.
(f) Polyglactin: Vicryl®.
• Composite techniques
∘ Polypropylene mesh and polymethylmethacrylate (PMMA):
- Mesh is cut generously, leaving excess to secure construct to defect.
- PMMA is added to fill defect.
- A 2nd layer of mesh added
- Protect vital structures from heat of PMMA as it sets.
- Biologic materials: allografts or autografts.
- Gradually revascularised and remodelled into autologous tissue.
- More resistant to infection, better for irradiated wounds.
Allografts (human ADM)
(a) AlloDerm®: processed human dermis (not available in UK).
- Cellular components removed, extracellular
matrix and basement membrane preserved.
Xenografts
- Porcine
(a) Permacol® - crosslinked ADM.
(b) Strattice® - non-crosslinked ADM.
(c) Surgisis® - small bowel submucosa. - Bovine
(a) Tutopatch® - pericardium.
(b) Veritas® - pericardium.
(c) Surgimend® - non-crosslinked ADM.
What soft tissue cover options are there?
- Pectoralis major
- LD
- Rectus abdominis
- External oblique (rare)
Local FC / perforator flaps.
Omentum
What are the indications for free tissue reconstruction of chest wall defects?
∘ Salvage after the failure of pedicled flaps.
∘ Large defects unreconstructible with pedicled flaps, particularly after radiotherapy.
∘ Defects inaccessible to pedicled flaps.
∘ Intrathoracic deadspace.
FLAPS
∘ TFL
∘ LD
- Including serratus anterior on the same pedicle allows coverage of large defects.
∘ TRAM, VRAM or DIEP
∘ ALT +
- fascia lata for support and vastus lateralis for bulk.
∘ Scapular and parascapular flaps
- Supplied by the circumflex scapular artery, a branch of the subscapular artery.
- Gives a transverse cutaneous scapular branch and vertical parascapular branch.
What may cause posterior trunk defects?
Congenital
- Spina bifida
∘ Acquired
- Trauma
- Iatrogenic, following spinal instrumentation
- Tumour
- Pressure ulcer.
What flap options are available?
Cervical
1. Trapezius flap
∘ muscle or myocutaneous.
∘ Superficial branch of transverse cervical artery, from thyrocervical trunk.
∘ Superior muscle fibres are left intact to avoid ‘drop shoulder’.
Upper thoracic
• LD flap
• Trapezius flap (posterior i.c. perforators, but LD better)
• Scapular or parascapular flap
Lower thoracic
• LD flap
• Intercostal artery perforator flaps (small)
• Omentum (rare)
Lumbar
• Lumbar artery perforator flap
∘ superseded transverse lumbosacral flap (random pattern).
• SGAP flap
• LD flap (based on segmental supply; may not reach inferior lumbar defects).
• Omentum.
