Florian Ebel

Background: External ventricular drain (EVD)–associated infections (EVDAI) remain a relevant complication of acute hydrocephalus treatment following aneurysmal subarachnoid hemorrhage (aSAH). Whether radiological quantity and anatomical distribution of subarachnoid and ventricular blood impact EVDAI rates has not been thoroughly studied to date. Methods: This was a retrospective (2009–2023) analysis of patients with aSAH undergoing emergency ventriculostomy. Univariable and multivariable logistic regression analyses were used to assess the association between the Barrow Neurological Institute (BNI) grading scale for subarachnoid hemorrhage and the intraventricular hemorrhage (IVH) score for extent and anatomical distribution of intracerebral bleeding with EVDAI risk. Cox regression analysis was employed to investigate the relationship between hemorrhage extent and the timing of EVDAI onset. Results: One hundred and ninety-four patients with aSAH received 228 EVDs with a total of cumulative 2,258 EVD days. Overall EVDAI rates were 14% (27/194) per patient and 12% (27/228) per EVD. EVDAI was associated with a larger subarachnoid blood clot (BNI grade 4; odds ratio 6.66, 95% confidence interval 2.04–21.68; p = 0.002) and higher IVH scores (odds ratio 1.33, 95% confidence interval 1.05–1.69; p = 0.02). Intracerebral hemorrhage was more frequently localized in the posterior fossa in the EVDAI group (20% vs. 0%, p = 0.004). Multivariable analysis confirmed a positive independent correlation with larger blood clots. Cox regression demonstrated earlier EVDAI onset in association with higher BNI grades and IVH scores. Conclusions: Both the quantity and radiological distribution of subarachnoid and ventricular blood positively correlate with EVD-associated nosocomial meningitis, eventually accelerating an earlier infection onset. These findings should help guide future research on EVDAI prevention in patients with aSAH.

Assessment of ventricular size following endoscopic third ventriculostomy (ETV) often relies on linear measurements and indexes such as the Evans index (EI) and frontal and occipital horn ratio (FOHR). Long-term data on ventricular volume following ETV is scarce, which leads to uncertainties regarding optimal follow-up duration and whether ventricular size correlates with clinical outcomes. This study aims to analyze the longitudinal changes of ventricular volume following ETV for aqueduct stenosis (AS) in adults. We retrospectively analyzed radiological images and clinical records of adult patients who underwent ETV for AS between the years 2010 and 2020. The primary endpoint was the change in lateral and third ventricular (LTV) volume at various follow-up periods in patients who did not require revision surgery (successful ETV group). Cluster analysis was performed to identify distinct volumetric patterns, and logistic regression was used to analyze the correlation between ventricular volume changes and clinical symptom improvement. A total of 238 radiological images with 197 (82.8%) MRI and 41 (17.2%) CT scans from 46 patients were analyzed. Thirty-nine (84.8%) patients did not require revision surgery (successful ETV group). In the successful ETV group, LTV volume decreased by 19.6% within 3 months, 31% after 3–6 months, and 47.5% after 6–12 months. Two main clusters were identified: one with a mean LTV volume decrease of 56% and the other of 18.9% after 1 year. The presence of a pineal or tectal lesion (OR 3.94, p = 0.074) tended to be predictive of the former cluster, and the presence of a membrane in the aqueduct (OR 5.1, p = 0.036) was predictive of the latter. Volumetric changes were significantly greater than those measured by EI and FOHR postoperatively (p < 0.001) and at the last follow-up (p = 0.002). There was no association between LTV volume reduction and clinical improvement during the follow-up period (OR 1.03, [95% CI 0.99–1.06]; p = 0.195). Volumetric analysis provides a more accurate representation of ventricular size changes following ETV for AS. It demonstrates a continuous reduction in LTV volume during the first year after surgery, whereafter LTV volume appears to stabilize with a cumulative reduction of 38.7%, suggesting that lifelong imaging may be unnecessary in these patients. However, it does not predict the clinical outcome.

OBJECTIVE: The insertion of a ventriculoperitoneal shunt (VPS) is a common neurosurgical procedure, but the optimal entry site of the ventricular catheter is still under debate. In this study, the authors compare the parietal (Keen’s) and frontal (Kocher’s) entry sites in terms of the rate of revision surgery due to ventricular catheter misplacement, VPS dysfunction, and VPS infection. METHODS: The authors retrospectively analyzed the data on consecutive adults (age ≥ 18 years) who had undergone primary VPS insertion between 2010 and 2020 at two neurosurgical centers. One center regularly inserts the ventricular catheter frontally (frontal group); the other center, parietally (parietal group). The primary outcome of interest was the rate of ventricular catheter misplacement necessitating revision surgery. Secondary outcomes were functional outcome as measured by the modified Rankin Scale (mRS), rate of revision surgery for VPS dysfunction and infection, as well as early (≤ 30 days) and late (> 30 days) mortality rates. Propensity score matching was performed based on baseline variables, such as normal pressure hydrocephalus, postinfectious hydrocephalus, and idiopathic intracranial hypertension, which were identified as predictors of ventricular catheter misplacement using logistic regression analysis. RESULTS: Among 539 consecutive patients, 301 (55.8%) were in the frontal group and 238 (44.2%) in the parietal group. Postoperative rates of revision surgery due to misplacement were comparable in the two catheter entry site groups (frontal 14 [4.7%] vs parietal 11 [4.6%], p = 0.987). Rates of revision surgery for VPS dysfunction (14 [4.7%] vs 10 [4.2%], respectively, p = 0.802) and infection (22 [7.3%] vs 10 [4.2%], p = 0.13) exhibited no significant differences. Favorable functional outcomes (mRS score ≤ 2; 164 [76.3%] vs 174 [79.5%], respectively, p = 0.058) and early mortality rates (5 [1.7%] vs 6 [2.5%], p = 0.483) were similar between the groups. After propensity score matching, the primary and secondary outcome measures remained comparable between the groups. CONCLUSIONS: The entry site of the ventricular catheter in VPS surgery does not seem to affect proximal revision rates. Further, revision rates due to VPS dysfunction, VPS infection, and morbidity were comparable as well.

"Letter to the Editor. Reconsidering risk factors for ventriculostomy-related infections" published on 16 Jun 2023 by American Association of Neurological Surgeons.

The insertion of an external ventricular drain (EVD) is one of the most common neurosurgical procedures. Whether the weaning method (gradual or rapid) influences the ventriculoperitoneal shunt (VPS) insertion rate has not been conclusively established. The aim of this study is to provide a systematic literature review and conduct a meta-analysis of studies comparing gradual with rapid EVD weaning regarding VPS insertion rate. Articles were identified by searching the Pubmed/Medline, Embase, and Web of Science databases throughout October 2022. Two independent researchers assessed the studies for inclusion and quality. We included randomized trials, prospective cohort studies, and retrospective cohort studies, which compared gradual and rapid EVD weaning. The primary outcome was VPS insertion rate, whereas secondary outcomes were EVD-associated infection (EVDAI) rate and length of stay in the hospital and intensive care unit (ICU). Four studies directly comparing rapid versus gradual EVD weaning, with 1337 patients suffering from subarachnoid hemorrhage, were identified and included in the meta-analysis. VPS insertion rate was 28.1% and 32.1% in patients with gradual and rapid EVD weaning, respectively (relative risk 0.85, 95% confidence interval 0.49–1.46, p = 0.56). Further, the EVDAI rate was comparable between the groups (gradual group 11.2%, rapid group 11.5%, relative risk 0.67, 95% confidence interval 0.24–1.89, p = 0.45), whereas length of stay in the ICU and hospital were significantly shorter in the rapid weaning group (2.7 and 3.6 days, respectively; p < 0.01). Rapid EVD weaning seems comparable to gradual EVD weaning concerning VPS insertion rates and EVDAI, whereas hospital and ICU length of stay is significantly reduced.

Various cranioplasty techniques exist for the reconstruction of cranial bone defects. Patient-specific implants can be produced in-house using a recently developed 3D printer-assisted cranioplasty technique. However, the resulting cosmetic outcomes from the patient’s perspective are underreported. With our case series, we aim to present the clinical outcome, morbidity rate, patient-reported cosmetic results, and cost-effectiveness of patient-specific3D printer-assisted cranioplasty technique. This is a consecutive retrospective case series of adult patients undergoing cranioplasty using the patient-specific 3D printer-assisted technique. As primary endpoint, the functional outcome based on modified Rankin scale (mRS) at discharge and follow-up was assessed. A prospective telephone survey was conducted to collect and provide patient-reported outcomes. Thirty-one patients underwent patient-specific 3D printer-assisted cranioplasty, mostly to reconstruct frontotemporoparietal (61.3%) and frontotemporal defects with orbital involvement (19.4%). Good functional outcome (mRS ≤ 2) at discharge and during the last follow-up was achieved in 54.8% (n = 17) and 58.1% (n = 18) patients. Overall, the rate of clinically relevant surgery-related complications was 35.5% (n = 11). Postoperative epidural hematoma/collection (16.1%) and infections (12.9%) were the most frequent complications. Permanent morbidity occurred in one patient (3.2%) with postoperative acute ipsilateral vision loss after frontotemporal cranioplasty with orbital involvement. No surgery-related mortality occurred. The mean patient-reported cosmetic satisfaction score was 7.8 ± 1.5, with 80% of patients reporting satisfying or very satisfying cosmetic results. No significant differences were seen between the different defect localization regarding the cosmetic outcome. The mean manufacturing costs of a patient-specific 3D printer-assisted implant ranged from 748 to 1129 USD. Based on our case series, patient-specific 3D printer-assisted cranioplasty is cost-effective and leads to satisfying cosmetic results, especially in large defects and/or defects with complex geometry.

The evacuation of a chronic subdural hematoma (cSDH) is one of the most common procedures in neurosurgery. The aim of this study was to assess the influence of drainage suction in the surgical treatment of cSDH on the recurrence rate. Post hoc analysis was conducted on two randomized controlled trials (cSDH-Drain-Trial and TOSCAN trial) stratifying a total of 581 patients into active or passive drain type. Of the 581 patients, 359 (61.8%) and 220 (37.9%) were stratified into the active and passive drainage groups, respectively. The reoperation rate following postoperative recurrence was 23.1% and 14.1% in the active and passive drainage groups, respectively (p < 0.011). After propensity score matching, the differences in recurrence rate remained significant (26.6% versus 15.6%, p = 0.012). However, the functional outcome (mRS) at 6–12 months did not differ significantly (median [IQR]) between the 2 groups (passive drainage group 0.00 [0.00, 2.00], active drainage group 1.00 [0.00, 2.00], p = 0.431). Mortality was comparable between the groups (passive drainage group 12 (5.5%), active drainage group 20 (5.6%), p = 0.968). In the univariate analysis, active drainage, short (<48 h) duration of drainage, and early (<48 h) postoperative mobilization were significantly associated with a higher recurrence rate. However, the multivariate logistic regression model could not confirm that any of these parameters were significantly associated with recurrence. Our post hoc analysis proposes that using a passive instead of an active drain might be associated with a reduced recurrence rate after evacuation of a cSDH. We suggest gathering further evidence by means of a randomized controlled trial.