From February 2018 to February 2019, all adult patients admitted to the Union Hospital Neurosurgery Center for EVD placement were eligible for inclusion. After the application of strict exclusion criteria, all enrolled patients were randomly divided into two groups. The patients in Group A received Standard-EVD, and the remaining patients in Group B received Tunneled-EVD. A linear incision was made for T-EVD. The distal end of the catheter was inserted approximately 5 cm until cerebrospinal fluid was readily obtained, and then the catheter was tunneled approximately 4-5 cm from the insertion point. Finally, an external CSF drainage system was connected to the catheter. For the S-EVD patients, they secured the catheter at the original incision site after insertion, and an external CSF drainage system was also connected to the catheter. The rates of ERI were compared between the two patient groups. The odds ratios and χ² test were used to analyze the results.
One hundred twenty patients were randomly divided into two groups and underwent EVD placement. Among them, 60 patients in Group A received S-EVD, and 60 patients in Group B received T-EVD. Finally, 51 patients in Group A and 50 patients in Group B met all of the study inclusion/exclusion criteria and were thus eligible for inclusion in the evaluation of ERI rates. All clinical features of the two groups were similar. A total of 12 patients' (11.9%) CSF cultures were positive for infection. Ten (19.6%) patients who underwent S-EVD had CSF-positive cultures, while only 2 (4.0%) patients who underwent T-EVD had CSF-positive cultures (P = 0.034). Additionally, 8 patients in Group A and 1 patient in Group B were complicated with CSF leakage (P = 0.039).
Compared to S-EVD, T-EVD, when performed according to a previously established perioperative management protocol, resulted in lower infection and CSF leakage rates. We recommend that T-EVD should be preferentially performed when surgeons determine whether a catheter can be removed within 10 days, and the catheter used for EVD should be removed as soon as permitted by the clinical circumstances 1).
In 155 patients Ortolano et al. 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, they 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.
Arroyo-Palacios et al performed a retrospective study with 50 aSAH patients with reported weaning trial admitted to our institution between 03/2013 and 08/2014. By reviewing clinical notes and pre/post-brain imaging results, 32 patients were determined as having passed the weaning trial and 18 patients as having failed the trial. MOCAIP algorithm was applied to ICP signals to form a series of artifact-free dominant pulses. Finally, pulses with similar mean ICP were identified, and amplitude, Euclidean, and geodesic inter-pulse distances were calculated in a 4-h moving window.
While the traditional measure of mean ICP failed to differentiate the two groups of patients, the proposed amplitude and morphological inter-pulse measures presented significant differences (p ≤ 0.004). Moreover, receiver operating characteristic (ROC) analyses showed their usability to predict the outcome of the EVD weaning trial (AUC 0.85, p < 0.001).
Patients with an impaired CSF system showed a larger mean and variability of inter-pulse distances, indicating frequent changes on the morphology of pulses. This technique may provide a method to rapidly determine if patients will need placement of a shunt or can simply have the EVD removed 3).