Penetrating Head Injuries (Mario Löhr)

Penetrating head injuries Mario Lรถhr, Neurosurgeon

Neurochirurgische Klinik und Poliklinik Direktor: Prof. Dr. Ralf-Ingo Ernestus

Overview: Penetrating head injury (PHI)

BASIC KNOWLEDGE

PRACTICAL SKILLS

1. Definition, Mechanisms, Barriers

5. How to extend a scalp laceration

2. Challenges in PHI

6. Treatment of depressed skull fract.

3. Therapeutical goals

7. Removal of bone fragments etc.

4. Initial assessment in head injury

8. Dural lacerations and CSF leaks 9. Epidural bleeding

OVERVIEW 11. Treatment of PHI 12. Indications for antibiotics 13. Indications for anticonvulsants

10. Brain herniation

Definition

Open head injury: „Air hits brain“ Penetrating head injury (PHI)

•

laceration of the dura

• +/- laceration of the scalp •+

fracture of the skull (convexity, base)

• +/- laceration of the brain

Mechanismus of injury

Common reasons for PHI

• any contact injury of skull • missile / gunshot injuries • bomb blast injury • stab wounds

Skin and dura mater as essential barriers

Barriers • skin • dura - mechanical protection of the brain - invasion of microorganisms - CSF extrusion

 REPAIR + CLOSE (at the expense of bone, if needed)

Challenges in PHI

• Laceration of wound edges

Challenges in PHI

• Laceration of wound edges • Extruding brain • Contamination of brain parenchyma

Challenges in PHI

• Laceration of wound edges • Extruding brain • Contamination of brain parenchyma • Penetration of foreign bodies

Challenges in PHI

• Laceration of wound edges • Extruding brain • Contamination of brain parenchyma • Penetration of foreign bodies • Extruding CSF

Challenges in PHI

• Laceration of wound edges • Extruding brain • Contamination of brain parenchyma • Penetration of foreign bodies • Extruding CSF • Epi- / subdural bleeding

Challenges in PHI

• Laceration of wound edges • Extruding brain • Contamination of brain parenchyma • Penetration of foreign bodies • Extruding CSF • Epi- / subdural bleeding • Risk of CSF-fistula (impairment of wound healing, risk of infection)

Challenges in PHI

• Laceration of wound edges • Extruding brain • Contamination of brain parenchyma • Penetration of foreign bodies • Extruding CSF • Epi- / subdural bleeding • Risk of CSF-fistula (impairment of wound healing, risk of infection) •Risk of infection (meningitis, epi- / subdural empyema)

Therapeutical goals

• Most important aim: transform the open HI into a closed HI (closure of skin + dura) • Practical guideline: - debridement - cleaning - removal of bone fragments, foreign material, extruded brain (?)

- hemostasis - closure of skin, dura

Initial assessment in head injury

• GCS at the scene  severity of HI, prognosis • pupillary size + reactivity • examination of skull (depressed #, entry / exit wounds, extruding brain) • examination of face (rhino- / otoliquorrhea)

Initial assessment in head injury

• GCS at the scene  severity of HI, prognosis • pupillary size + reactivity • examination of skull (depressed #, entry / exit wounds, extruding brain) • examination of face (rhino- / otoliquorrhea)

Initial assessment in head injury

• GCS at the scene  severity of HI, prognosis • pupillary size + reactivity • examination of skull (depressed #, entry / exit wounds, extruding brain) • examination of face (rhino- / otoliquorrhea)

Initial assessment in head injury

• GCS at the scene  severity of HI, prognosis • pupillary size + reactivity • examination of skull (depressed #, entry / exit wounds, extruding brain) • examination of face (rhino- / otoliquorrhea)

Challenges in PHI

• Laceration of wound edges

How to extend a scalp laceration

Blood supply of the cranial convexity: • four major vessels • perpendicular course

Extension of galeal laceration: • consider flap vascularity

How to extend a scalp laceration

Vertical incision ďƒ transsection of vascular supply (except near midline)

How to extend a scalp laceration

Prefer linear incisions

How to extend a scalp laceration

More extensive of calvaria: • curvilinear incision • consider blood loss

Depressed skull fracture

Indication for treatment in precarious conditions: • penetrating injury with underlying dural laceration +/- brain herniation • neurological abnormalities by displaced fragments (hemiparesis, aphasia, seizures) Principles of treatment: • remove bone fragments • replace? (contamination, size, fixation)

Don´t worry about defects of the calvaria!

Depressed skull fracture crossing major sinus

Depressed skull fracture crossing major sinus

Lesion of sagittal sinus Danger of lethal bleeding !

Removal of bone fragments and foreign bodies

Contamination of brain (dirt, hair etc.): • rinse / flush out as far as possible Bone fragments displaced into brain: • remove accessible fragments cautiously • preserve viable brain

Removal of bone fragments and foreign bodies

Contamination of brain (dirt, hair etc.): • rinse / flush out as far as possible Bone fragments displaced into brain: • remove accessible fragments cautiously • preserve viable brain Foreign bodies displaced into brain: • do not remove outside OR

Removal of bone fragments and foreign bodies

Contamination of brain (dirt, hair etc.): • rinse / flush out as far as possible Bone fragments displaced into brain: • remove accessible fragments cautiously • preserve viable brain Foreign bodies displaced into brain: • do not remove outside OR • do not remove bullets • no association between complete removal of retained bone and epilepsy1,2 (1) (2)

Arabi B: Prognostic factors in the occurence of posttraumatic epilepsy after penetrtatin head injury suffered during military service. Neurosurg Focus, 2000 Amirjamshidi A: Minimal debridement or simple wound closure as the only surgical treatment in war victims with low-velocity penetrating head injuries.

Surg Neurol, 2003

Dural laceration / CSF leaks

• Localization (each 50%) - penetrating wounds of cranial vault - base fractures: oto-/rhinorrhea • Time of onset 72% within 2 weeks after injury • Incidence of infection in PHI1 CSF leak: 49.5%. No CSF leak: 4.6%

 Clear recommendation to treat CSF leak / fistula • Head elevation • Repeated spinal taps, spinal drainage (not recommended in elevated ICP due to risk of herniation) • Dural repair (cranial vault)

• Mortality in PHI1

• Rhinoliquorrhea: prohibit to blow nose

CSF leak: 22.8%. No CSF leak: 4.6%

• Otoliquorrhea by laterobasal fractures is usually self-limiting

(1)

Arabi B: CNS infections after military missile head wounds. Neurosurgery, 1998

Dural laceration / CSF leaks of the cranial vault

You should repair the dura • if arachnoid is lacerated • in case of CSF-leakage • in case of brain herniation

Dural repair not necessary • small dural defect („burr/bullet hole“) • intact arachnoid membrane • sever brain swelling • suspected poor prognosis

Dural laceration / CSF leaks of the cranial vault

You should repair the dura • if arachnoid is lacerated • in case of CSF-leakage • in case of brain herniation

Dural repair not necessary • small dural defect („burr/bullet hole“) • intact arachnoid membrane • severe brain swelling • suspected poor prognosis

Dural laceration / CSF leaks of the cranial vault

You should repair the dura • if arachnoid is lacerated • in case of CSF-leakage • in case of brain herniation

Dural repair not necessary • small dural defect („burr/bullet hole“) • intact arachnoid membrane • severe brain swelling • suspected poor prognosis

Dural laceration / CSF leaks of the cranial vault

Principles of dural repair: • dural injury often extends beyond bone margins  bone opening until intact dura is visible • use autologous grafts: pericranium fascia (temporalis fascia, fascia lata) muscle (temporal muscle), fat • tension-free fixation, running sutures (best: watertight closure)

Epidural bleeding skin/galea

periosteum calvaria dura mater Epidural hematoma

Epidural bleeding skin/galea

periosteum calvaria

Dural tack-up suture

dura mater

Herniating / bleeding brain

• (indication) depends on viability - if intact, cover it (see duroplasty) - if severely destroyed / necrotic, resect • hemostasis - matter of patience - with bipolar (low current, for several seconds) - repetitive irrigation with warm saline - moistened swabs - 3% H2O2

Comprehensive overview: treatment of PHI

•

50 y/o female,

•

head smashed by hammer beats

•

GCS 6, pupils equal, reacting to light

•

inspection: extruding brain



Suspected diagnosis: Depressed skull fracture with dural laceration

Comprehensive overview: treatment of PHI

1

Remove hair, palpate (fracture of) the skull

Comprehensive overview: treatment of PHI

1

Remove hair, palpate (fracture of) the skull

2

Clean the field (NaCl, 3% H2O2)

Comprehensive overview: treatment of PHI

1

Remove hair, palpate (fracture of) the skull

2

Clean the field (NaCl, H2O2)

3

Inspect the wound carefully.

Debride devitalized tissue.

Comprehensive overview: treatment of PHI

1

Remove hair, palpate (fracture of) the skull

2

Clean the field (NaCl, H2O2)

3

Inspect the wound carefully.

Debride devitalized tissue. Enlarge lacerations by incision.

Comprehensive overview: treatment of PHI

1

Remove hair, palpate (fracture of) the skull

2

Clean the field (NaCl, H2O2)

3

Inspect the wound carefully.

Debride devitalized tissue. Enlarge lacerations by incision-

4

Remove accessible in-driven bony fragments, skin and hair (but not at the expense of viable brain).

Achieve adequate hemostasis.

Repair and watertight closure of the lacerated dura and skin.

Medical management: Antibiotics

Antibiotics • preantibiotic area: infection rate 60%1 • Penicillin (World War II): 6-13% • broad spectrum antibiotics: 1-11%2 • risk factors for development of infection: CSF-leak, air sinus wounds, wound dehiscence

 clear recommendation for antibiotic prophylaxis (1)

Whitaker R: Gunshot wounds of the cranium, Br J Surg, 1916

(2)

Arabi B: CNS infections after military missile head wounds. Neurosurgery, 1998

Medical management: Antibiotics

Antibiotics

Which antibiotic? For how long?

• preantibiotic area: infection rate 60%1

• not really settled !

• Penicillin (World War II): 6-13%

• survey of US neurosurgeons3

• broad spectrum antibiotics: 1-11%2

cephalosporin (87%) [Staph. + Strep.]

• risk factors for development of infection:

chloramphenicol (24%)

CSF-leak, air sinus wounds,

penicillin (16%)

wound dehiscence

aminoglykoside (12%) vancomycin (6%), metronidazole

 clear recommendation for antibiotic

• duration > 5 days (depending on nature of wound)

prophylaxis (1)

Whitaker R: Gunshot wounds of the cranium, Br J Surg, 1916

(2)

Arabi B: CNS infections after military missile head wounds. Neurosurgery, 1998

(3)

Kaufman HH: A national survey of neurosurgical care for penetrating head injury.

Surg Neurol, 1991

Medical management: Anticonvulsants

Anticonvulsants • high rate of seizures in PHI (4-10% first week, 30-50% lifetime)1 • acute seizure: diazepam i.v.

• efficacy of phenytoin in reducing the incidence of seizures in the first week after closed and penetrating head injury2 • prophylactic treatment with anticonvulsants beyond 1 week: no reduction of late seizures  not recommended (1) (2)

Salazar AM: Epilepsy after penetrating head injury. A report of the Vietnam Head Injury Study. Neurology, 1985 Temkin NR: A randomized,double-blind study of phenytoin for the prevention of post-traumatic seizures. N Engl J Med, 1990

(3)

Kaufman

Thank you for your attention !