External ventricular drain causes brain tissue damage: an imaging study.

BACKGROUND: An external ventricular drain (EVD) is used to measure intracranial pressure (ICP) and to drain cerebrospinal fluid (CSF). The procedure is generally safe, but parenchymal sequelae are reported as a possible side effect, with variable incidence. We investigated the mechanical sequelae of EVD insertion and their clinical significance in acute brain-injured patients, with a special focus on hemorrhagic lesions. METHODS: Mechanical sequelae of EVD insertion were detected in patients by computed tomography (CT) and magnetic resonance imaging (MRI), performed for clinical purposes. RESULTS: In 155 patients we studied the brain tissue surrounding the EVD by CT scan (all patients) and MRI (16 patients); 53 patients were studied at three time points (day 1-2, day 3-10, >10 days after EVD placement) to document the lesion time course. Small hemorrhages, with a hyperdense core surrounded by a hypodense area, were identified by CT scan in 33 patients. The initial average (hyper- + hypodense) lesion volume was 8.16 ml, increasing up to 15 ml by >10 days after EVD insertion. These lesions were not accompanied by neurologic deterioration or ICP elevation. History of arterial hypertension, coagulation abnormalities and multiple EVD insertions were significantly associated with hemorrhages. In 122 non-hemorrhagic patients, we detected very small hypodense areas (average volume 0.38 ml) surrounding the catheter. At later times these hypodensities slightly increased. MRI studies in 16 patients identified both intra- and extracellular edema around the catheters. The extracellular component increased with time. CONCLUSION: EVD insertion, even when there are no clinically important complications, causes a tissue reaction with minimal bleedings and small areas of brain edema.

Iatrogenic Pseudoaneurysm After Continuous Adductor Canal Block.

No major complications have been associated with the ultrasound-guided continuous adductor canal block (cACB). We present a case of iatrogenic pseudoaneurysm in a branch of the superficial femoral artery in a 44-year-old patient after a cACB for knee surgery. Both anesthesia and surgery were completed uneventfully. The postoperative day 3 examination showed a complete quadricep impairment and a large hematoma in a medial-anterior part of the thigh, and laboratory tests reported hemoglobin = 7.2 g dL. The computed tomography scan revealed the pseudoaneurysm (16 × 16 × 18 mm) that was successfully embolized after selective catheterization. The patient was discharged regularly on postoperative day 12.