Decompressive craniectomy in Traumatic Brain Injury


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Decompressive craniectomy

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Decompressive craniectomy in Traumatic Brain Injury

  1. 1. Decompressive craniectomy for TBI Dr. Joe M Das Senior Resident Dept. of Neurosurgery
  2. 2. • • • • • • • • • • History ICP and methods to reduce it Definition Craniectomy vs craniotomy Current evidence Indications Types Procedure Complications & their management Cranioplasty
  3. 3. History • Ancient Egypt and Greece – TBI, epilepsy, headache, mental illness • First described by Annandale (1894) • Surgical decompression to treat elevated ICP – Kocher (1901) and Cushing (1905) – subtemporal and suboccipital Cushing H. The establishment of cerebral hernia as a decompressive measure for inaccessible brain tumors; with the description of intermuscular methods of making the bone defect in temporal and occipital regions. Surg Gynecol Obstet.1905;1:297–314
  4. 4. Harvey Cushing spent several months in the lab of Kocher in 1900, performing cerebral surgery and first encountering the Cushing reflex .
  5. 5. • Erlich (1940) – For all head injuries with persistent coma for more than 24-48 hrs • Rowbotham (1942) – All traumatic comas which improved at first and when medical treatment was ineffective for 12 hrs • Munro (1952) – If intra-op, the brain was contused and swollen • Guerra (1999) – personal results of 20 years – 2nd tier therapy in refractory ICP Guerra WK, Gaab MR, Dietz H. et al: Surgical decompression for traumatic brain swelling: indications and results. J Neurosurg 90:187-196, 1999
  6. 6. ICP • In a normal adult, the cranial vault can accommodate an average volume of approximately 1500 mL. • V Intracranial space = V Brain + V Blood + V CSF • The normal ICP ranges between 10 and 15 mm Hg in an adult. • CPP = MAP – ICP • Systemic hypertension is required to maintain cerebral perfusion Monro A (1783). Observations on the structure and function of the nervous system. Edinburgh: Creech & Johnson. Kelly G (1824). "Appearances observed in the dissection of two individuals; death from cold and congestion of the brain". Trans Med Chir Sci Edinb 1: 84–169.
  7. 7. Methods to reduce ICP ACSSurgery Principles & Practice - Section 7 / Chapter 2 Injuries to the Central Nervous System
  8. 8. • The limits of welltolerated ICP together with lowering of CPP: – SAH – 18-20 mm Hg – Malignant Sylvian stroke – 20-22 mm Hg – Trauma – 25 mm Hg – Slow growing tumors and HCP – 30-40 mm Hg Aschoff A., Schwab S., Spranger M, et al - The value of intracranial pressure monitoring in acute hemispheric stroke, Neurology 47 (1996): 393-398
  9. 9. • A craniectomy of 8 cm  23 ml additional volume (1.5% of total cerebral volume). • For real decompression, 12 cm or more (86 ml additional volume) • Superior to the one realised by hyperventilation (2 mm Hg lowering of pCO2), ventricular tap of 20-30 ml and without the risk of loop diuretics.
  10. 10. Brain facts
  11. 11. Definition • Decompressive hemicraniectomy and durotomy is a surgical technique used to relieve the increased intracranial pressure and brain tissue shifts that occur in the setting of large cerebral hemisphere mass, or space-occupying lesions. • In general, the technique involves removal of bone tissue (skull) and incision of the restrictive dura mater covering the brain, allowing swollen brain tissue to herniate upwards through the surgical defect rather than downwards to compress the brainstem.
  12. 12. Craniotomy vs craniectomy • Craniotomy – the bone flap is returned to its previous location • Craniectomy – the bone flap is not returned
  13. 13. Current evidence • Evidence supporting emergent Decompressive Craniectomy in Trauma remains controversial • In animal studies, craniectomy has been a/w increased cerebral edema,hemorrhagic infarcts and cortical necrosis 1 • Decreased ICP2 • Improved Oxygen tension2 • Improved cerebral perfusion2 1.Forsting M, Reith W(1995) ; Wagener S et al(J Neurosurg 94:693-696, 2001) 2. Burket W. Zentralbl Neurochir 50:318-323, 1988; Gaab M et al Childs brain 5:484-498, 1979 Hatashita S, J Neurosurg 67:573-578, 1987
  14. 14. “The role of decompressive craniectomy in TBI and in the control of intracranial hypertension remains a matter of debate.” Youmans Neurological Surgery - Volume 4, Section XI, page 3442
  15. 15. Brain facts • Brain generates 10-23 Watts of electricity • You have an average of 70,000 thoughts per day
  16. 16. Indications • Severe TBI – Heterogeneous lesions in cerebral parenchyma – Focal (contusions/hematoma) and diffuse • Malignant MCA infarction • Aneurysmal SAH • Others – – – – Central venous thrombosis Encephalitis Metabolic encephalopathies Intracerebral hematoma Neurosurg Clin N Am 24 (2013) 375–391; Tarek Y. El Ahmadieh et al
  17. 17. Indications & Contraindications in TBI • Indications: – – – – – Coma or semicoma (GCS < 9) Pupillary abnormalities, but respond to mannitol Supratentorial lesion with midline shift on CT Refractory ICP despite best conventional therapy Age: initially < 80 years , now 70 years (Of patients who were > 70 years, 75% were dead) • Contraindications: – Fatal brain stem damage – GCS < 4 or fixed and dilated bilateral pupils
  18. 18. When to perform? • Bifrontal decompressive craniectomy is indicated within 48 hours of injury for patients with diffuse, post-traumatic cerebral edema and medically refractory elevated ICP. • Subtemporal decompression, temporal lobectomy, and hemispheric decompressive craniectomy can be considered as treatment options for patients who present with diffuse parenchymal injury and refractory elevated ICP who also have clinical and radiographic evidence for impending transtentorial brain herniation. Bullock MR, Chesnut R, Ghajar J, et al. Neurosurgery 2006;58(Suppl 3) Surgical management of traumatic parenchymal lesions. :S25–46 [discus-sion: Si-iv]. - BTF Guidelines
  19. 19. Guidelines • Up to date there are no specific guidelines or protocols stating exactly when or in what circumstances DC is appropriate, but there are some recommendations: 1. The North American Brain Trauma Foundation suggests DC may be the procedure of choice in the appropriate clinical context and also considering the use of DC in the first tier of TBI management. (Bullock et al, 2006) 2. European Brain Injury Consortium recommend DC as an option for refractory intracranial hypertension in all ages. (Maas et al,1997) 3. A Cochrane review (2006) recommended DC may be justified in some children with medically intractable ICP after head injury but concluded there was no evidence to support its routine use in adults. (Sahuquillo & Arikan, 2006)
  20. 20. Types
  21. 21. Brain facts • Stress alters brain cells and function • Music increases brain organisation
  22. 22. Decompressive hemicraniectomy • • • • Foam / rubber donut No pins Cervical spine precautions Don’t compress the jugulars
  23. 23. DHC • • • • • • • • • Supine Rolled towel beneath ipsilateral shoulder Head towards contralateral side Mark midline Incision – Reverse question mark Posterior extent – 15 cm behind key hole Deepened down to cranium Myocutaneous flap reflected Five burr holes are made in the following locations: (1) temporal squamous bone superior to the zygomatic process inferiorly, (2) keyhole area behind the zygomatic arch anteriorly, (3) along the superior temporal line posteroinferiorly, and in the (4) parietal and (5) frontal parasagittal areas
  24. 24. • Smaller craniectomy  Damage to cortical veins and parenchyma • Dura dissected off from beneath the bone • Bur-holes connected • Bone flap removed • Temporal decompression • Wax bone edges • Dural tack-up stitches • Dural opening (controlled manner) with radial incisions in stellate fashion • Closure with dural substitute and after keeping suction drain
  25. 25. Brain facts • 2,50,000 neurons are produced per minute in early pregnancy • Brain stops growing at around 18 years
  26. 26. Bifrontal craniectomy • • • • • • • • • • Bifrontal contusions / diffuse cerebral edema Mark midline and coronal suture Bicoronal incision (2-3 cm behind coronal) Myocutaneous flap brought over the orbital rim (Preserve supra-orbital nerves) Bur-holes – b/l keys, b/l squamous temporal, straddling the SSS just posterior to coronal suture Bone flap Temporal decompression Bone wax, dural tack-up stitches Divide the anterior portion of SSS and falx Dural opening wide Kjellberg RN, Prieto A Jr: Bifrontal decompressive craniotomy for massive cerebral edema. J Neurosurg 34:488-493, 1971
  27. 27. What is the percentage reduction in ICP attained by DC? • Opening the dura has been shown to improve the reduction in ICP from 30% (dura left intact) to 85% (dura opened)
  28. 28. Brain facts • Dreaming requires more activity than any waking function • Oxytocin makes you feel love
  29. 29. Complications • • • • • 50-55 % Abnormalities in CSF absorption Expansion of hematomas after decompression Syndrome of the trephined Infection
  30. 30. CSF absorption disorders • Subdural hygromas & hydrocephalus • Causes: – Ruptured arachnoid  One-way valve – Pressure gradients between hemispheres – Alteration in brain’s shape • Treatment – Ventriculostomy & oversewing if CSF leak – VP shunt (programmable) – Cranioplasty
  31. 31. Expanding hematomas • New or existing mass lesions can develop postoperatively, especially given the high incidence of coagulopathy and platelet dysfunction • Evolution of both contusions and extra-axial hematomas can occur after the tamponading effects of cerebral edema, and elevated ICP has been relieved by decompressive craniectomy. • Postoperative imaging is recommended especially in the setting of no ICP monitoring
  32. 32. SYNDROME OF THE TREPHINED • Variety of symptoms that can develop following craniectomy, including fatigue, headache, mood disturbances, and even motor weakness. • Mechanisms: – CSF flow abnormalities – Direct atmospheric pressure on the brain – Disturbances in cerebral blood flow. • Often resolves with replacement of the bone flap • There is no evidence that it is harmful or that delay of cranioplasty can result in long-term consequences
  33. 33. Cranioplasty • Usually carried out 6 to 8 weeks after the DC, assuming that the patient has recovered from the initial injury and hydrocephalus or brain swelling is not present. • In the interim - “hockey helmet” • Autologous bone flap, (frozen after the initial surgery / kept in abdominal subcutaneous tissue) is used and provides good cosmetic results. • The bone flap remains sterile in a −70°C freezer for many months. • Autoclaving of the bone (e.g., if contaminated by a compound scalp wound before cranioplasty)  reduce the viability of the graft.
  34. 34. Cranioplasty • Complication associated with abdominal preservation of bone flap - bone resorption (510%) due to hypovascular bone necrosis and sepsis of the flap. • Other materials - methyl methacrylate and titanium mesh when the bone is heavily comminuted or contaminated. • For large, cosmetically important defects, the use of casts, stereolithographic models, and CT-based “computer-assisted design” reconstruction technology
  35. 35. Conclusion • IC-HTN results from many disease processes. • Decompressive craniectomy can be life preserving procedure. • Selection criteria remains in involution. • Best outcomes are achieved in young patients treated early in course of disease.