SUBDURAL AND EXTRADURAL BLEEDING

Be sure you are familiar with the methods of controlling bleeding in Section 63.9.

EQUIPMENT A general set (4.11), a self retaining mastoid or thyroid retractor such as Mallison’s, a brace, a perforator, burrs, a curved dissector, a dural elevator, a dural hook or fine needle and holder, a wide bore cannula and stillette, a fine suction tube, and a large Volkmann’s spoon or a small teaspoon. Horsley’s bone wax to plug the bleeding diploe, and a sterile pointed match stick. A bottle of warm sterile saline and a drip set, or a bowl of warm saline and a bladder syringe.

ANAESTHESIA See Primary Anaesthesia Section A 16.8. General anaesthesia is best because you can hyperventilate the patient, which will make his brain contract. A method of local anaesthesia is described below.

CAUTION! Keep his airway clear. The slightest obstruction will make his brain swell.

PREPARATION Work quickly; shave the patient’s whole scalp so that you can operate on both sides if necessary. Take care not break his skin. Include his ears in the area you prepare.

Close his eyes, pad them and seal them with strapping, so that the fluid used for skin preparation or blood cannot drip into them.

Prepare one of his thighs so that you can take a fascial graft, if necessary, as in Fig. 63-17.

POSITION Position him yourself. Support the patient’s head carefully with sandbags or a kidney dish, so that it projects over the end of the table, and does not move about when you operate. If you are using local anaesthesia, strap him to the table. After preparing him, scratch the sites of the burr holes, and inject local anaesthetic. If you don’t do this, you may not know where you are when his nose and eyes are hidden under the drapes.

DRAPES Wet a towel with antiseptic and wrap it round the base of the patient’s cranium. Stitch it to his head so that you can move his head with the towel attached. Expose his occiput, the tops of his ears, his zygomas, and the whole of his forehead, so that you can get at the whole of his head. If possible, lay the drapes from his face across to an overhead table, so that the anaesthetist can get at his face. Ideally, use the special frame made for the purpose.

Arrange to minimize venous bleeding by adjusting the slope of the table, so that the patient’s head is above his heart. Make sure that nothing obstructs the veins of his neck.

SITING THE BURR HOLE

Site the burr hole according to the rules in Section 63.4. The classical position is as follows.

THE CLASSICAL POSITION Make the burr hole midway between the posterior margin of the patient’s orbit and his external meatus 2 cm above his zygomatic arch, and 1 cm in front of his ear.

CAUTION ! The common mistake is to make the hole too high.

Make a hockey stick incision starting at the lower border of his zygoma 4 cm in front of his ear, and carry it upwards and backwards for 8 cm, as A, Fig. 63-19. Experts make a shorter incision.

If you are using local anaesthesia, infiltrate the line of the incision with anaesthetic solution. Also anaesthetize a line from the margin of the patient’s orbit anteriorly to his mastoid posteriorly. Take care to anaesthetize the tissues above his ears.

Inject the anaesthetic solution at right angles to his skin in several places, so as to infiltrate the lower part of his temporalis muscle and block his deep temporal nerves as they turn upwards. Use a generous quantity of solution and make his whole temporalis fossa insensitive.

Control bleeding by asking your assistants to press the edges of the wound (B, Fig. 63-9). Pick up the edges of the patient’s galea in haemostats and evert them. When you remove them at the end of the operation bleeding will have stopped. Make a T–shaped incision in his temporalis fascia (C), and turn it back as two short flaps (D). The small horizontal incision above his zygomatic arch makes access to the inferior surface of his brain easier.

Split the patient’s temporalis muscle from top to bottom in the line of its fibres, and separate it from his skull with a curved dissector (E).

Insert a self–retaining retractor, to expose about 4 cms of his skull (F).

AN ALTERNATIVE PROCEDURE FOR A DESPERATE EMERGENCY

INCISION This is quicker, and many operators prefer it to the classical one in Fig. 63-9, especially if they are in a hurry in the middle of the night.

To minimize bleeding infiltrate the line of the incision with adrenaline in saline (or local anaesthetic solution). Make this incision over the temporal lines of the patient’s skull (you can feel these) above the mid part of his zygomatic arch. Cut down through it right down to his pericranium in one quick deep incision. Quickly free the cut edges of his galea from his skull, pick them up with several haemostats, and turn them over to control bleeding.

Make the burr hole in his upper temporal region at the edge of his temporalis muscle in the position in Fig. 63-6 marked ’alternative site for temporal burr hole’. Nibble downwards fast. Separate the dura, and insert a catheter down inside the patient’s skull to drain the clot. Because you are not going through his temporalis muscle, you can be inside his skull much faster. You will leave a larger hole in his skull, but this is not important.

USING A PERFORATOR AND BURRS

Place the knob at the top of the brace in the palm of your left hand; take its handle in your right hand. With the perforator in position, make a funnel shaped hole in the bone as in A, Fig. 63-10, until you just see the pale blue of the normal dura, or the dark purple of an extradural clot, then stop!

CAUTION! (1) Don’t go on any further, because you may pierce the patient’s dura and lacerate his cortex. This is very easily done. (2) The squamous temporal bone is often thin so don’t press too hard.

Replace the perforator with a burr (B) and enlarge the hole. Avoid the smaller burrs and choose one which is large enough to rest on the edges of the hole. A small burr can easily go through into the brain. Use a certain amount of force, but lock your shoulder muscles, so that the brace is under control, if the bone gives way. The burr must not suddenly go thorugh the skull into the brain, as in F!

Stop turning when the bite on the burr increases suddenly, because this shows that it is now through to the inner table. Stop while there is still a rim of inner table round the edge of the burr hole, as in D, Fig. 63-10. Don’t go on until you have made a parallel sided hole E, or the burr will certainly go through into the brain. You should be able to make a large enough hole with a single burr. If not, replace it with a larger one one, until the hole is just large enough to let you put in the nibblers.

Nibbling should not be necessary in the first instance because most subdural haematomas can be drained through an ordinary sized burr hole. Only nibble if you need more room. Push the dura gently away from the inner table with a dural elevator (G, and H), so that it is not torn when you insert the nibbler to enlarge the edge of the hole (I).

The cut edges of the bone will bleed. Suck away the blood and don’t apply wax until you are about to close the wound.

WHAT DO YOU SEE THROUGH THE BURR HOLE?

Make sure you have a good light. The normal brain and dura should pulsate; if they do not, suspect that there is something abnormal underneath. If you don’t see anything, enlarge the burr hole a little. This is why it is best to make burr holes away from the line of the middle meningeal artery, not over it.

If a meningeal artery spurts at you as soon as you make the burr hole, you probably cut it with your instruments, and an extradural haematoma is not present.

If there is clot immediately under the hole, the patient has an extradural haematoma, so see below. You will not see the dura or the middle meningeal artery because these will have been displaced inwards by the clot.

If the patient’s dura looks abnormally purple, he has a subdural haemorrhage, or occasionally an intracerebral one, so deal with it as described below. This is more common than extradural bleeding.

If his dura is its normal pinkish white and swollen, the brain underneath is swollen. Open his dura, to make sure that the swelling is due to his brain and not to a subdural clot, then make another burr hole.

If his dura is normal in colour and not swollen, explore the hole for 5 cm in all directions with the dural elevator. There may be clot close to the hole which the elevator may reveal. If you find blood, nibble towards it, or make a new hole.

If thorough exploration reveals no clot, make more burr holes, in the order shown in Fig. 63-6.

EXTRADURAL HAEMORRHAGE

You made a burr hole and found clot immediately under it. Nibble the hole in the patient’s skull to make it larger. If necessary, lengthen the skin incision upwards and backwards, and extend the split in his temporalis muscle. Retract the tissues widely, so that you get a good look into the hole. If you are able to turn back a small flap, do so. This is quicker than enlarging a burr hole by nibbling.

Nibble away the bone in the direction of the clot; this is usually towards the base of the skull. The common error is to remove too little bone. If necessary, nibble away ruthlessly to get the access you need. A cranioplasty can be done later if he survives to need it. It is seldom necessary. The hole should be at least 7 cm in its maximum diameter. With a low temporal haematoma, remove bone well down to and including the pterion, which is the outer end of the sphenoid ridge. This is the only way you can remove clot lying low under the temporal lobe. Use a curved dissector to separate the patient’s dura from his skull each time you nibble more bone.

After you have removed bone, wait a few minutes to allow the circulation in the patient’s brain to adjust itself to the new conditions.

CAUTION! (1) Don’t disturb the clot until you are in a position to control bleeding. (2) Don’t put your finger into the wound to try to remove the clots, because the extra compression may kill him. Instead, remove the clot, a little at a time with a teaspoon or a curved dissector, or suck it out, or syringe it away forcibly with warm saline.

Watch for further bleeding, and if necessary, nibble towards it—this is very important; don’t worry about how much bone you remove.

If there is no further bleeding, after you have removed the clot, don’t hunt for the injured artery, instead close the wound. The patient’s dura will probably be slack showing that there is no significant brain swelling. Pull up his dura to the bone with black silk stitches through the surrounding pericranium and temporalis muscle. You may have to make a small incision in the dura to do so. This is good practice anyway, because you may find some removable subdural clot. If you don’t do this, clot will reaccumulate. Usually, the brain does not expand rapidly, unless air or saline gets underneath it.

If the bleeding is arterial and floods up into the wound as you remove the clot, it is certainly coming from his middle meningeal artery, so try to find it. Syringing with warm saline may help. The best way may be to make a hole in the dura beside the bleeder, and catch it with a haemostat. Or, pick it up with a sharp hook and pass a needle round it, so that you do not mistakenly damage any cortical veins. When you have controlled bleeding you can coagulate the vessel with diathermy or tie it. Immediate coagulation with diathermy usually results in the vessel ’burning back’ and continuing to bleed.

If the bleeding is venous, it is either coming from the veins which accompany his meningeal artery, or from the veins of his dura. If it is very severe it may be coming from a tear in his saggittal sinus, or its lacunae. Try to find the bleeding point and stop it as described in Section 63.9. In about 10% of cases the blood is coming from a sinus, so raise the patient’s head and insert a pack as described below. If there is a venous ooze from everywhere, insert a suction drain.

If you have secured the main bleeding point, but there is much persistent bleeding, don’t hurry. Leave a pack in place. Go away and wait for 10 minutes. It will probably settle spontaneously over the next hour, and allow you to close the wound. Provided you are able to replace the blood that is lost, you can afford to wait. Don’t forget to remove the pack!

If the clot extends backwards under the patient’s parietal bone, the posterior branch of his middle meningeal artery has probably been torn. You cannot tie this from your present incision. So try to tie its main trunk. If this is impossible make another burr hole 4 cm above and behind his ear. This is the burr hole marked ’X’ in Fig. 63-6. Fortunately, it is rarely needed.

If the vessels in a bone groove or tunnel are bleeding, apply Horsley’s bone wax, or plug them with a sterile pointed match stick. Do the same if his diploic veins are bleeding. Some surgeons say that match sticks don’t work and that these vessels are better plugged with muscle.

If arterial bleeding comes from the under surface of the patient’s brain, his middle meningeal artery may have ruptured at or close to his foramen spinosum. Retract his brain and the dura so as to expose it, and plug it with bone wax, or a sterile pointed match stick. Fortunately this is rarely necessarily.

If you cannot find the bleeding vessel, pack pieces of haemostatic gauze, or temporalis muscle, between the patient’s dura and the bone where the bleeding is coming from. Hold them in place by stitching the dura to the pericranium over the edges of the hole in his skull, as in Figure 63-19. Insert a suction drain and raise the patient’s head.

If bleeding is uncontrollable, it is probably coming from a torn sagittal sinus. Raise the patient’s head. Leave the wound open for a few hours, or even until the next day. Pack It lightly with gauze towards the bleeding point, keep it covered with sterile dressings, and transfuse him with several units of fresh blood. Give him calcium gluconate. Severe bleeding of this kind is also rare, which is lucky because it is often fatal.

SUBDURAL HAEMORRHAGE AFTER A HEAD INJURY

You have found purple clot under the patient’s dura. Extend the skin incision, and enlarge the hole with nibblers, If necessary, which it usually is not. Hold up his dura on a hook. Use a No. 11 blade on a holder to make a cross–shaped incision in it. Interpreting what you find may be difficult. His brain may be contused and lacerated, with some clot and blood in the subdural space. This is not in itself a significant compressing lesion. He will only benefit if you can remove a subdural clot about 1.5 cm thick or more. Remove it in the same way as for an extradural haemorrhage.

If moderate bleeding is still taking place, enlarge the burr hole in the direction of the bleeding, and then try to seal it with diathermy, or by one of the methods in Section 63.9.

If there is a venous ooze from everywhere, which is impossible to control, leave it and insert a drain, preferably a mild suction drain.

If torrential bleeding occurs from a tear in a large venous sinus or from deep in the patient’s brain, its source may be impossible to find, or repair. Try to control it as in Section 63.9. This type of bleeding is seen in acute subdural haemorrhage; his outlook is bad.

If you have controlled all bleeding, close the dura without a drain. Otherwise, leave a rubber drain in when you close the wound. Stitch it to the skin, take great care with asepsis and remove it after 24 hours. Some surgeons consider that a Paul’s tube rubber drain is useless.

BLEEDING INTO THE BRAIN AFTER AHEAD INJURY

You have made a burr hole; the dura under it is purple and bulges into the incision. Insert a wide bore cannula, or a Tuohy needle, into the swollen area and remove the stilette. Purple fluid may exude. If it does not, gently aspirate 2 or 3 times in various directions. If this fails, widen the hole in the skull, incise the cerebral cortex and suck out the clot, or syringe it away.

FURTHER BURR HOLES WHEN THESE ARE NECESSARY

EXTRADURAL HAEMORRHAGE is rarely bilateral. So if you find extradural bleeding, and the patient is recovering, and the X–ray shows no fracture on the other side, there is no need to make any more holes.

SUBDURAL BLEEDING. In 20% of cases bleeding is bilateral, so never make less than 4 holes.

When you make more holes, do so in the order shown in Fig. 63-6. Make the parietal holes through a separate longitudinal incision over the point of maximum convexity of the patient’s skull, above and behind his ear. If this is unsuccessful, make a frontal burr hole in the line of his pupil 2 cm behind his hair line. If you find nothing here, make the same three burr holes on the other side.

Unless you find extradural bleeding, always make at least one bole on the other side, and don’t stop operating, even if the patient is dying. The relief of his cerebral compression is his only chance of living. You can cut more burr holes very quickly. Incise the skin and periosteum with a single cut, quickly elevate the periosteum, insert a retractor, and then apply the perforator.

In subdural bleeding you will usually find clots through temporal burr holes when the patient’s history is less than 2 weeks, and through frontal or parietal ones in more chronic cases. Sometimes, there is no clot, only pale yellow fluid under tension, but treatment is the same.

CLOSING THE WOUND AFTER MAKING BURR HOLES

SUBDURAL HAEMORRHAGE There is no need to suture the patient’s dura, or to insert a drain routinely. Most wounds will drain quite satisfactorily into his temporalis muscle. Only insert a drain if you have been unable to control bleeding. If you do insert one, be sure to remove it in 24 hours.

Occasionally, you may need to close a gap in his dura with fascia lata (63-17).

EXTRADURAL HAEMORRHAGE If you can, insert an extradural suction drain. Some surgeons don’t insert one if they have been able to draw the patient’s dura up well.

ALL PATIENTS Stop bleeding from the cut edges of the patient’s skull by pressing Horsley’s bone wax into it all round. Use fine monofilament sutures on curved needles to bring the edges of his temporalis muscle together.

If the patient’s brain bulges into the wound, and makes it difficult to close his dura, close it with a fascia lata graft, while hyperventilating him. Give him mannitol and furosemide as described below.

Suture his temporalis fascia. It contracts during the operation, so you will probably only be able to sew up its lower half. Careful closure will diminish the evidence of a bony defect in his skull.

Close his galea with buried sutures of monofilament or chromic catgut, cut the sutures close to the knot, or their ends may project from the wound, prevent healing, and encourage infection. If closing the wound is difficult, close it with monofilament, as in Fig. 63-14.

DIFFICULTIES WITH BURR HOLES

If you DON’T HAVE A BRACE AND BURRS, use a hammer and gouges and control them carefully. Small taps with a large hammer are better than large taps with a small one. Or, borrow a drill from a garage.

Some hospitals have trephines instead of burrs. If you use a trephine, start with a small one and hold it in a handle, or a brace. Put the locating pin in the trephine and start to make the hole with this. It will be hard work! As soon as the trephine has started to bite, remove the pin. It must not go through the dura.

If a CHILD needs burr holes, fit the perforator into the handle for it, and open his skull with this. Then go straight to the nibbler, without using burrs. A child’s skull is thin with no distinct inner and outer table, so a brace and burrs, and especially a drill, can be dangerous. You may be able to remove the blood from a haematoma in a baby with a large needle without using a perforator.

If a BURR GOES STRAIGHT THROUGH the patient’s dura into his brain, this is not as dangerous as you might suppose, and he will probably recover. It should never happen, but when it does happen, as in F, Figure 63-10, it usually does so in a child.

If BRAIN OOZES LIKE TOOTHPASTE from an open hole in a patient’s skull, pass a tracheal tube, and hyperventilate him. His brain will suck itself in, and he may recover. If his intracranial pressure is high enough, his brain can ooze from a burr hole, or from an open wound in his skull.

If, after hyperventilation and a thorough search for bleeding, the patient’s BRAIN BULGES THROUGH THE WOUND, there is either deep intracerebral bleeding or oedema. There is nothing you can do for deep intracerebral bleeding, but you can reduce oedema with mannitol. Give him 500 ml of 10% mannitol (50 g) over 30 to 60 minutes. Repeat this every 6 to 8 hours if his consciousness improves, but don’t exceed 200 g in 24 hours. Drain his bladder with a catheter because he should have a marked diuresis. From the second day onwards for 3 or 4 days give him frusemide 40 to 80 mg intravenously daily. Steroids are useless.