Ramon Torné, Ana Rodríguez-Hernández and Michael T. Lawton
Intraoperative rupture can transform an arteriovenous malformation (AVM) resection. Blood suffuses the field and visualization is lost; suction must clear the field and the hand holding the suction device is immobilized; the resection stalls while hemostasis is being reestablished; the cause and site of the bleeding may be unclear; bleeding may force technical errors and morbidity from chasing the source into eloquent white matter; and AVM bleeding can be so brisk that it overwhelms the neurosurgeon. The authors reviewed their experience with this dangerous complication to examine its causes, management, and outcomes.
From a cohort of 591 patients with AVMs treated surgically during a 15-year period, 32 patients (5%) experienced intraoperative AVM rupture. Their prospective data and medical records were reviewed.
Intraoperative AVM rupture was not correlated with presenting hemorrhage, but had a slightly higher incidence infratentorially (7%) than supratentorially (5%). Rupture was due to arterial bleeding in 18 patients (56%), premature occlusion of a major draining vein in 10 (31%), and nidal penetration in 4 (13%). In 14 cases (44%), bleeding control was abandoned and the AVM was removed immediately (“commando resection”). The incidence of intraoperative rupture was highest during the initial 5-year period (9%) and dropped to 3% and 4% in the second and third 5-year periods, respectively. Ruptures due to premature venous occlusion and nidal penetration diminished with experience, whereas those due to arterial bleeding remained steady. Despite intraoperative rupture, 90% of AVMs were completely resected initially and all of them ultimately. Intraoperative rupture negatively impacted outcome, with significantly higher final modified Rankin Scale scores (mean 2.8) than in the overall cohort (mean 1.5; p < 0.001).
Intraoperative AVM rupture is an uncommon complication caused by pathological arterial anatomy and by technical mistakes in judging the dissection distance from the AVM margin and in mishandling or misinterpreting the draining veins. The decrease in intraoperative rupture rate over time suggests the existence of a learning curve. In contrast, intraoperative rupture due to arterial bleeding reflects the difficulty with dysplastic feeding vessels and deep perforator anatomy rather than neurosurgeon experience. The results demonstrate that intraoperative AVM rupture negatively impacts patient outcome, and that skills in managing this catastrophe are critical.
Sergio García, Ramon Torné, Jhon Alexander Hoyos, Ana Rodríguez-Hernández, Sergio Amaro, Laura Llull, Antonio López-Rueda and Joaquim Enseñat
Reliable tools are lacking to predict shunt-dependent hydrocephalus (SDHC) development after aneurysmal subarachnoid hemorrhage (aSAH). Quantitative volumetric measurement of hemorrhagic blood is a good predictor of SDHC but might be impractical in the clinical setting. Qualitative assessment performed using scales such as the modified Fisher scale (mFisher) and the original Graeb scale (oGraeb) is easier to conduct but provides limited predictive power. In between, the modified Graeb scale (mGraeb) keeps the simplicity of the qualitative scales yet adds assessment of acute hydrocephalus, which might improve SDHC-predicting capabilities. In this study the authors investigated the likely capabilities of the mGraeb and compared them with previously validated methods. This research also aimed to define a tailored mGraeb cutoff point for SDHC prediction.
The authors performed retrospective analysis of patients admitted to their institution with the diagnosis of aSAH between May 2013 and April 2016. Out of 168 patients, 78 were included for analysis after the application of predefined exclusion criteria. Univariate and multivariate analyses were conducted to evaluate the use of all 4 methods (quantitative volumetric assessment and the mFisher, oGraeb, and mGraeb scales) to predict the likelihood of SDHC development based on clinical data and blood amount assessment on initial CT scans.
The mGraeb scale was demonstrated to be the most robust predictor of SDHC, with an area under the curve (AUC) of 0.848 (95% CI 0.763–0.933). According to the AUC results, the performance of the mGraeb scale was significantly better than that of the oGraeb scale (χ2 = 4.49; p = 0.034) and mFisher scale (χ2 = 7.21; p = 0.007). No statistical difference was found between the AUCs of the mGraeb and the quantitative volumetric measurement models (χ2 = 12.76; p = 0.23), but mGraeb proved to be the simplest model since it showed the lowest Akaike information criterion (66.4), the lowest Bayesian information criterion (71.2), and the highest R2
Nagelkerke coefficient (39.7%). The initial mGraeb showed more than 85% specificity for predicting the development of SDHC in patients presenting with a score of 12 or more points.
According to the authors’ data, the mGraeb scale is the simplest model that correlates well with SDHC development. Due to limited scientific evidence of treatments aimed at SDHC prevention, we propose an mGraeb score higher than 12 to identify patients at risk with high specificity. This mGraeb cutoff point might also serve as a useful prognostic tool since patients with SDHC after aSAH have worse functional outcomes.
Maria A. Poca, Francisco Martínez-Ricarte, Juan Sahuquillo, Roberto Lastra, Ramón Torné and Maria S. Armengol
Continuous intracranial pressure (ICP) monitoring using an epidural sensor is a common technique used in selected neurosurgical patients. The aim of this study was to assess the safety and accuracy of the Neurodur-P epidural sensor in the clinical setting.
The zero drift, as well as the medical and technical complications, of using the Neurodur-P sensor placed in the epidural space was evaluated in 106 patients with hydrocephalus of varying causes or with suspected intracranial hypertension.
The median duration of ICP monitoring was 8 days (interquartile range [IQR] 6–12 days). In 78 (73.6%) of the 106 patients the pressure reading was recorded at sensor removal. No zero drift was observed in 28 sensors. The median drift was 0 mm Hg with an IQR of −1 to 1 mm Hg. No significant differences were found between patients monitored for ≤ 5 days and those monitored for > 5 days (t = 535, p = 0.100). No correlation was found between zero drift and monitoring time (r = 0.153, p = 0.181). Of the 83 patients with a follow-up computed tomography scan, 3 showed a < 1 ml collection of blood at the catheter tip. No clinical infections could be attributed to the devices. Only 1 sensor malfunctioned.
Continuous ICP monitoring using the Neurodur-P sensor is safe, reliable, and easy to perform. At present, using this device is the authors' standard method for the long-term monitoring of patients with alterations in complex cerebrospinal fluid dynamics or with implanted shunts.
Sergio García-García, Diego Culebras and Ramón Torné