The document discusses the history, current evidence, indications, techniques, complications and controversies surrounding decompressive craniectomy, which is a surgical procedure that involves removing a portion of the skull to relieve increased intracranial pressure from brain injuries or swelling. It provides details on performing decompressive hemicraniectomy and bifrontal craniectomy, as well as managing potential complications like subdural hygromas and hydrocephalus.

1. DR PRAVEEN K TRIPATHI
Decompressive craniectomy:
Indication, technique, present
status ,future and controversies
6 April 2016
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2.  History
 ICP and methods to reduce it
 Definition
 Craniectomy vs craniotomy
 Current evidence
 Indications
 Types
 Procedure
 Complications & their management
 Cranioplasty 6 April 2016
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3. “If there’s no CSF pressure, but brain pressure exists, then
pressure relief must be achieved by opening the skull”
-Kocher 1901
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4. 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.
 Now a days , DC as treatment modality of raised ICP , and
most controversial of all
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5. The surgical removal of a portion of the skull, either
for medical or superstitious reasons is known in the
anthropological context as ‘‘trephanation.’’
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6.  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
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7. 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
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8. Feed forward cycle of raised ICP
Increase
ICP
Decrease
CPP
Disrupt
cellular
metabolism
Disruption
of osmotic
gradient
Influx of
water in
cell
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10. Methods to reduce ICP
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 The limits of well-tolerated 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

12.  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.
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13. 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.
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14. Craniotomy vs craniectomy
 Craniotomy – the bone flap is returned to its previous
location
 Craniectomy – the bone flap is not returned
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15. 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
 Decreased ICP
 Improved Oxygen tension
 Improved cerebral perfusion 6 April 2016
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16. “The role of decompressive craniectomy in
TBI and in the control of intracranial
hypertension remains a matter of
debate.”
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19. 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
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20. 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)
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21. Indications & Contraindications in TBI
Contraindications:
 Fatal brain stem damage
 GCS < 4 or fixed and dilated bilateral pupils
 Central herniation are universally poor candidates for
DC
 The postresuscitation GCS score, especially the motor
score, is one of the most important factors to consider in
patient selection.
 Exclude possible influences on GCS scores such as
intoxication, hypoxia, hypotension, and paralytics or
sedatives. 6 April 2016
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22. PROGNOSIS
 Younger patients generally have better outcomes; however,
age alone should not be used as an exclusion criterion.
 The presence of midline shift on computed tomography
(CT) of the brain is highly predictive prognostically. The
degree of shift is inversely related to outcome, and elevated
ICP is presumed.
 Absent or compressed cisterns are also predictive of
elevated ICP and a poor outcome.
 Early decompression (within 4 hours of injury) results in
profound decreases in mortality and improvement in
functional outcome at 6 months.
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23. When to perform?
 Once ICP becomes unmanageable and signs of brainstem
compression are noted, DC may be lifesaving, but at the
expense of severe neurological impairment.
 Bifrontal decompressive craniectomy is indicated within 4-8
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.
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24. Guidelines
 Up to date there are no specific guidelines or protocols, 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)
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25. Decompressive hemicraniectomy
 Foam / rubber donut
 No pins
 Cervical spine precautions
 Don’t compress the jugulars
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26. DECOMPRESSIVE HEMICRANIECTOMY
 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
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27.  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
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28. SKIN INCISION
 a standard large
question mark or
reverse question mark
incision is used.
 The skin incision
should start 1 cm in
front of the tragus at
the zygomatic arch and
extend posteriorly
above the auricle,
 Upward over the
parieto-occipital area,
and forward to the
frontal region to the
hairline. 6 April 2016
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35. Extent of bone
resection
A, Extent of bone resection
necessary for unilateral
decompression. A temporal
craniectomy to the level of the
middle fossa floor must be
performed to avoid strangulation
of the temporal lobe.
B, Extent of bone resection
necessary for bifrontal
decompression extending across
the orbital rims and down to the
base of the temporal fossa
bilaterally.
C, Three-dimensional view of
the skull after unilateral
decompression. 6 April 2016
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36. CAUTIONS
 The craniotomy itself for
unilateral DC must
encompass a large enough
area to prevent brain
herniation and strangulation,
typically from
 just lateral to the superior
sagittal sinus,
 Frontally to the midpupillary
line,
 Inferiorly to the floor of the
temporal fossa, and posteriorly
to the parieto-occipital area
 In cases of
intraparenchymal
hemorrhage, especially
mixed-density contusions
 Avoid aggressive
débridement of contusions
to preserve potentially
viable tissue
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37. 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
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52. REPLACING BONE INTRAOPERATIVELY
 Allow pco2 to rise intraoperatively and observe the brain for several
minutes before deciding to replace the bone flap, in addition to taking
into account the following:
 The degree of preoperative midline shift relative to the volume of the
mass lesion evacuated,
 The appearance of the cisterns on the preoperative CT scan,
 The absolute volume of hematoma removed,
 The appearance of the hemisphere at surgery (degree of swelling and
 Hemorrhage, pulsatility, appearance of the vasculature),
 The age of the patient,
 The mechanism of injury,
 The presence of other non–central nervous system (CNS) injuries
(especially pulmonary),
 The time from injury to evacuation of the initial lesion, and
 The extent and correctability of the coagulopathy.
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53. 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)
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54. Complications
 The most frequent complications seen with decompressive
surgery are hygromas (26%) and hydrocephalus (14% to
29%).
 Wound infection and dehiscence,
 Seizures
 Syndrome of the trephine, and secondary brain injury.
 Expansion of hematomas after decompression
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55. CSF absorption disorders
Subdural hygromas
 Hygromas frequently occur on the ipsilateral side after
decompressive surgery, probably because of altered CSF dynamics
 Most resolve spontaneously without intervention.
 They may be treated by observation alone, isolated or serial lumbar
puncture, temporary continuous lumbar drainage, lumboperitoneal
shunting, or ventriculoperitoneal shunting.
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
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56. 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
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57. 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
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58. 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.
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59. Cranioplasty
 Complication associated with abdominal preservation
of bone flap - bone resorption (5-10%) 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
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60. Critical size of defect
 Bone defects > 2 cm on the cerebral convexity
and bone defects of glabrous frontal region
 No need for repair in
Defects below the temporal & occipital muscles
Very elderly
Children < 6 yrs in whom dura is not damaged
Parietal area defect < 5 cm2
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61. AUTO BONE GRAFT
 Wrap in blood soaked sponge for 4-6 hrs
 More than 6 hrs → 10 % serum / 90 % salt
solution at 3°C.
 Don’t expose to air for more than 30 min.
 Normal saline is toxic
 Avoid antibiotic soak
 Split bone graft – Outer & inner tables split
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62. 6 April 201662

63. 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.
 The decision to proceed with decompressive
craniectomy should take into consideration several
factors including family wishes and reasonable
expectations of level of recovery. 6 April 2016
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64. 6 April 201664