[Prevention of venous perioperative thromboembolism in ENT and maxillofacial surgery]

There are few studies of poor methodological quality on the risk of thromboembolism in head and neck surgery. The incidence of symptomatic deep vein thrombosis is estimated between, 0.1% and 0.6%. The patient's risk factors (cancer, alcoholism, smoking, malnutrition) determine for the assessment of the potential benefit of thromboembolism prophylaxis. No method can be recommended based on the literature. In patients receiving anticoagulant therapy undergoing superficial head and neck surgery or dental extraction, the literature suggest to continue anticoagulation throughout the perioperative period.

Thromboprophylaxie en chirurgie rachidienne traumatologique et non traumatologique

The risk of deep vein thrombosis (DVT) after spinal cord injury is very high. Without prophylaxis the incidence of DVT using venography is 81% and the risk of symptomatic DVT is between 12 and 23%. The risk is much lower in elective spine surgery. After discectomy or laminectomy on less than two spine levels, the risk of DVT is less than 1%. After spinal fusion or extended laminectomy, the risk can be estimated between 0.3 and 2.2%. A prophylaxis is recommended for all patients after spinal cord injury (grade A). The association of a mechanical method and heparin is recommended (grade B). The duration of prophylaxis is 3 months in patients with a motor deficit (grade C). No prophylaxis is recommended after discectomy or limited laminectomy in patients without additional risk factors. Mechanical methods are recommended after spinal fusion or extended laminectomy. For patients with additional risk factors a low molecular weight heparin is recommended.

Thromboprophylaxie en neurochirurgie et en neurotraumatologie intracrânienne

The incidence of deep vein thrombosis (DVT) is between 20 and 35% using contrast venography, with a rate of symptomatic DVT between 2.3 and 6% in neurosurgery without any prophylaxis. The risk of DVT is poorly evaluated in head injured patients but is around 5%. Specific risk factors in neurosurgery are: a motor deficit, a meningioma or malignant tumour, a large tumour, age over 60 years, surgery lasting more than 4 hours, a chemotherapy. The benefit of mechanical methods or low molecular weight heparin (LMWH) for the prevention of DVP in neurosurgery is demonstrated (grade A). Each method decreases the risk by about 50%. A postoperative prophylaxis with a LMWH does not seem to increase the risk of intracranial bleeding (grade C). There is no demonstrated benefit to begin a prophylaxis with LMWH before the intervention. The duration of the prophylaxis is 7 to 10 days but this has not been scientifically determined.

[Pulmonary embolism of cement during vertebroplasty]

A 62-year-old woman with severe osteoporosis experienced pulmonary embolism by polymethylmethacrylate after percutaneous vertebroplasty. The patient immediately developed respiratory and cardiac distress, and a computed tomographic scan revealed the presence of cement in the pulmonary circulation. Proper techniques can minimize the risk of pulmonary embolism during percutaneous vertebroplasty: adequate preparation of cement and fluoroscopy during the procedure are recommended.

Œdème pulmonaire neurogénique au cours des hémorragies sous-arachnoïdiennes et brain natriuretic peptide

We report two cases of neurogenic pulmonary oedema following subarachnoid haemorrhage. A 58-year-old woman became increasingly dyspneic and needed oxygen support during a few days. A 53-year-old woman rapidly developed clinical and laboratory signs of respiratory failure, recovering in 48 hours. In both cases, chest radiography showed bilateral diffuse infiltrates, electrocardiogram revealed ST abnormalities, and cardiac troponin I level was elevated. In both patients, pro brain natriuretic peptide level was increased whereas global cardiac function was normal. The factors initiating its secretion are discussed.

Modifications hémodynamiques cérébrales et systémiques au moment du réveil en neurochirurgie

Major complications after intracranial surgery occur in 13-27% of patients. Among multiple causes, haemodynamic and metabolic changes of anaesthesia recovery may be responsible for intracranial complications. Recovery from neurosurgical anaesthesia is followed by an increase in body oxygen consumption and catecholamines concentrations. However, in normothermic patients, theses changes are usually mild and not prevented by a 2-h recovery delay. Systemic hypertension is common after neurosurgery and a link between perioperative hypertension and intracranial haemorrhage has been established. The cerebral consequences of recovery associate cerebral hyperaemia and increased ICP in patients with a tight brain at the end of surgery. Cerebral hyperaemia may promote or exacerbate cerebral haemorrhage or oedema. This has been demonstrated in patients operated for subdural haematoma removal or undergoing carotid surgery. Prevention of hypothermia and pain are key factors to prevent metabolic changes. Beta-blockers seem to be suitable agents to obtain haemodynamic control in neurosurgical patients.

[Anaesthesia for patients with intracranial hypertension due to cerebral oedema]

The main objective for anaesthesia in patients with intracranial hypertension (ICH) is to maintain the cerebral perfusion pressure (CPP). Before the operation, the assessment of the level of intracranial pressure relies on the Glasgow coma score and the signs of ICH on the CT-scan. In the perioperative period, repeated transcranial Doppler examinations may help in determining the adequate CPP. Haemodynamic and respiratory complications are common after subarachnoid haemorrhage or head injury. Careful preoperative screening of the cardiovascular and respiratory system is mandatory before anaesthesia. There is no recommended anaesthetic technique for patients with ICH. Nitrous oxide should be avoided in patients with severe ICH or during emergency surgery. Theoretically, intravenous anaesthesia is a better choice than inhalation anesthesia because of the cerebral vasodilatation induced by inhalation agents. In the most severe cases thiopental is the only anaesthetic agent to consider. Treatment of hypovolaemia with fluid loading and the early use of vasoactive agents can be recommended to maintain CPP. Before intracranial surgery, large doses of mannitol have been demonstrated to improve neurological recovery in brain injured patients. The urinary losses due to the infusion of mannitol should be replaced with isotonic saline. Emergence and extubation are best performed in the intensive care unit under close systemic and cerebral haemodynamic control.

[Endoscopic third ventriculostomy for management of obstructive hydrocephalus secondary to supratentorial intraventricular hematoma. Case report]

We report two cases of intraventricular hematoma with obstructive hydrocephalus. We perform endoscopic treatment of the hydrocephalus: aspiration of the hematoma associated with a third ventriculostomy. Both patients respectively aged 59 and 74 years had an obstructive hydrocephalus due to intraventricular hemorrage. The patient neurological status worsen at day 6 for patient No. 1 and at day 4 for patient No. 2. Endoscopic ventriculoscopy was performed respectively at day 6 and at day 5. Operatively, immediate vision was poor but was progressively improved by repetitive irrigation with Ringer-lactate (RL). Obstruction of the right Monro foramen by clot was observed. Introduction of the neuroendoscope into the third ventricle was possible after suction of the hematoma. Perforation of the floor of the third ventricle was performed after identification of the mammillary bodies and the infundibulum. Neurological status recovered within 10 days after surgery and the patients were referred to a medical unit. The patients were independent at home. The one-year MRI follow-up study showed a functional acqueduc in case 1 and a non-functional acqueduc in case 2 indicating in this case that the ventriculocisternotomy was useful. Intraventricular hematoma is not a contraindication for endoscopic third ventriculostomy. If possible, waiting for 6 or 5 days to allow the structuring of the blood clot and using large irrigation RL may facilitate the endoscopic procedure. This indication for endoscopic third ventriculostomy constitutes an alternative to external ventricular drainage which is significatively associated with complication (infection and obstruction). We cannot affirm that the removal of the clots and ventriculocisternostomy versus temporary external drainage avoids secondary hydrocephalus.