Use of the Woven EndoBridge Device for Sidewall Aneurysms: Systematic Review and Meta-analysis.

BACKGROUND: The Woven EndoBridge device was originally approved to treat intracranial wide-neck saccular bifurcation aneurysms. Recent studies have suggested its use for the treatment of sidewall intracranial aneurysms with variable success. PURPOSE: Our aim was to evaluate the safety and efficacy of the Woven EndoBridge device for sidewall aneurysms using a meta-analysis of the literature. DATA SOURCES: We performed a systematic review of all studies including patients treated with the Woven EndoBridge device for sidewall aneurysms from inception until May 2022 on Scopus, EMBASE, MEDLINE, the Web of Science, and the Cochrane Central Register of Controlled Trials. STUDY SELECTION: Ten studies were selected, and 285 patients with 288 sidewall aneurysms were included. DATA ANALYSIS: A random-effects meta-analysis of proportions using a generalized linear mixed model was performed as appropriate. Statistical heterogeneity across studies was assessed with I2 statistics. DATA SYNTHESIS: The adequate occlusion rate at last follow-up was 89% (95% CI, 81%-94%; I2, = 0%), the composite safety outcome was 8% (95% CI, 3%-17%; I2 = 34%), and the mortality rate was 2% (95% CI, 1%-7%; I2 = 0%). Aneurysm width (OR = 0.5; P = .03) was the only significant predictor of complete occlusion. LIMITATIONS: Given the level of evidence, our results should be interpreted cautiously until confirmation from larger prospective studies is obtained. CONCLUSIONS: The initial evidence evaluating the use of the Woven EndoBridge device for the treatment of wide-neck sidewall intracranial aneurysms has demonstrated high rates of adequate occlusion with low procedural complications. Our findings favor the consideration of the Woven EndoBridge device as an option for the treatment of sidewall aneurysms.

Persistent neurological deficit from iodinated contrast encephalopathy following intracranial aneurysm coiling. A case report and review of the literature.

Neurotoxicity from iodinated contrast agents is a known but rare complication of angiography and neurovascular intervention. Neurotoxicity results from contrast penetrating the blood-brain barrier with resultant cerebral oedema and altered neuronal excitability. Clinical effects include encephalopathy, seizures, cortical blindness and focal neurological deficits. Contrast induced encephalopathy is extensively reported as a transient and reversible phenomenon. We describe a patient with a persistent motor deficit due to an encephalopathy from iodinated contrast media administered during cerebral aneurysm coiling. This observation and a review of the literature highlights that contrast-induced encephalopathy may not always have a benign outcome and can cause permanent deficits. This potential harmful effect should be recognised by the angiographer and the interventionalist.

HydroCoils, occlusion rates, and outcomes: a large single-center study.

BACKGROUND AND PURPOSE: The HydroCoil is an expansile hydrogel coil designed to produce a greater degree of volumetric packing within cerebral aneurysms when compared with bare platinum coils. This increased packing is, in turn, believed to decrease the risk of recurrence within aneurysms and hence the risk of their rupture in the long term. The aim of this work was to assess whether the use of HydroCoils and the proportion of HydroCoil used have any influence on the subsequent occlusion and recurrence rates of treated aneurysms. MATERIALS AND METHODS: A retrospective study was performed of 328 patients during 5 years at a single institution. The initial angiographic and follow-up angiographic occlusion rates were recorded as were any procedural complications. The proportion of HydroCoil used was described as the relative amount of HydroCoil length to the total coil length used during an aneurysm treatment, thus forming 4 groups: 0%-19%, 20%-49%, 50%-69%, 70%-100%, and the subgroups with 100%. RESULTS: Two hundred seventy patients had angiographic follow-up during an average of 13 months. The overall risk of permanent neurologic deficit and death was 3%. The rate of complete occlusion was 31% immediately postcoiling and 64.8% on follow-up. At the latest follow-up, 25.6% had residual necks and 9.6% had residual aneurysms. There was a statistically significant trend for HydroCoils to produce greater occlusion rates on follow-up when >70% HydroCoil was used (P = .025). The overall rate of recurrence for all aneurysms as a group was 15.5%. The retreatment rate was 6.6%. There has been 1 rebleed in the 328 patients. CONCLUSIONS: The overall results following the use of HydroCoils to occlude aneurysms compare well with those in other reported series. HydroCoils do produce a statistically significantly greater rate of occlusion when >70% of total aneurysm coil length is HydroCoil compared with coiling with <20% HydroCoil. There was no significant difference, however, in the recurrence or retreatment rate when comparing these groups.

Imaging characteristics of arteriovenous malformations simulating vascular tumors of the temporalis muscle: a report of two cases.

Arteriovenous malformations (AVMs) of the temporalis muscle are an extremely rare subgroup of head and neck AVMs. The authors report two cases presenting with temporal fossa tumor-like lesions. MRI demonstrated enlargement of the temporalis muscle with hypointensity on T1, hyperintensity on T2 and moderate contrast enhancement. Angiography shows slow arteriovenous shunting with a dense capillary blush of the entire muscle before draining into facial veins. The arterial supply is characteristic of being restricted to the temporalis muscle.

Thyroid dose during neurointerventional procedures: does lead shielding reduce the dose?

PURPOSE: To assess radiation dose to the thyroid in patients undergoing neurointerventional procedures and to evaluate dose reduction to the thyroid by lead shielding. METHODS AND MATERIALS: A randomized patient study was undertaken to evaluate the dose reduction by thyroid lead shields and assess their practicality in a clinical setting. Sixty-five patients attending for endovascular treatment of arteriovenous malformations (AVMs) and aneurysms were randomized into one of 2 groups a) No Thyroid Shield and b) Thyroid Lead Shield. Two thermoluminescent dosimeters (TLDs) were placed over the thyroid gland (1 on each side) at constant positions on each patient in both groups. A thyroid lead shield (Pb eq. 0.5 mm) was placed around the neck of patients in the thyroid lead shield group after the neurointerventional radiologist had obtained satisfactory working access above the neck. The total dose-area-product (DAP) value, number and type of digital subtraction angiography (DSA) runs and fluoroscopy time were recorded for all patients. RESULTS: Of the 72 patients who initially attended for neurointerventional procedures, 7 were excluded due to failure to consent or because of procedures involving access to the external carotid circulation. Of the remaining 65 who were randomized, a further 9 were excluded due to; procedureabandonment, unfeasible shield placement or shield interference with the procedure. Patient demographics included mean age of 47.9 yrs (15-74), F:M=1.4:1. Mean fluoroscopy time was 25.9 min. Mean DAP value was 13,134.8 cGy x cm(2) and mean number of DSA runs was 13.4. The mean relative thyroid doses were significantly different (p< 0.001) between the unshielded (7.23 mSv/cGy2 x 105) and shielded groups (3.77 mSv/cGy2 x 105). A mean thyroid dose reduction of 48% was seen in the shielded group versus the unshielded group. CONCLUSION: Considerable doses to the thyroid are incurred during neurointerventional procedures, highlighting the need for increased awareness of patient radiation protection. Thyroid lead shielding yields significant radiation protection, is inexpensive and when not obscuring the field of view, should be used routinely.

Segmental artery exchange technique for stable 4F guiding-catheter positioning in embolization of spinal vascular malformations.

For anatomic and technical reasons, it is often difficult to achieve guiding-catheter stability in the segmental arteries during embolization of spinal vascular lesions. We have developed a segmental artery exchange technique using a thin-walled 4F nontapered catheter that is safe and achieves a stable guiding-catheter position. This catheter accommodates both the flow-guided and variable-stiffness microcatheters, allowing selective catheterization and treatment of spinal vascular lesions.

Association between calcification of the cervical carotid artery bifurcation and white matter ischemia.

BACKGROUND AND PURPOSE: The association of cervical carotid artery bifurcation calcification to future stroke risk is unknown, though coronary artery calcification is a proven indicator of heart disease risk. Severity of white matter change has been correlated with future stroke risk. We sought to use white matter severity grade on CT as a surrogate predictor of relative future stroke risk and thus correlate white matter and future stroke risk with carotid calcification grade. METHODS: We retrospectively reviewed unenhanced neck and brain CTs in 209 patients. Carotid calcification degree was scored by the Agatston method, adapted from that commonly used to quantify coronary artery calcification. White matter change severity was scored by the European Task Force for Age-Related White Matter Change scale. Both scores were measured blinded to each other, and to age and sex covariables. Association was tested by univariate and multivariate analyses. RESULTS: Both carotid calcification and white matter scores were strongly, and independently, associated with increasing age (r = 0.61, P < .001; and r = 0.67, P < .001, respectively). Despite apparent association between carotid calcification and white matter scores on univariate analysis, there was no independent effect evident after adjusting for age as a covariant (r = 0.07, P = .14). Sex had no independent effect on white matter scores, though men had a marginally higher mean calcified carotid plaque load than women after controlling for age (P = .008). CONCLUSIONS: Carotid calcification scores do not independently predict severity of white matter ischemia. Future stroke risk, assessed by white matter severity scores, cannot be predicted from carotid calcium scores.

Bilateral infraoptic origin of anterior cerebral arteries: a rare anomaly and its embryological and clinical significance.

SUMMARY: We describe a case of bilateral infraoptic origin of the anterior cerebral arteries associated with an anterior communicating artery (ACOM) aneurysm. Anatomical variations of the anterior cerebral artery (ACA) are common; however, bilateral infraoptic course of the anterior cerebral artery is extremely rare. Since an infraoptic course of the ACA is associated with ACOM aneurysm formation, an understanding of the cerebrovascular anatomy and embryology is important for appropriate management of the aneurysm.

Accuracy of Voxel-Based and Algebraic Formula-Based Methods in Quantifying Cerebral Aneurysm Volume by 3D-Rotational Digital Subtraction Angiography. An In-Vitro and In-Vivo Study.

SUMMARY: Accurate knowledge of cerebral aneurysm volume would be valuable in guiding the volume of embolized material required for optimal filling of an aneurysm sac and recording percentage volume filling. Algebraic volumes are frequently estimated by algebraic volume formulae. 3D digital subtraction angiography (DSA) aids endovascular treatment planning and yields volumetric data. Our aim was to define the accuracy of 3D-DSA in quantifying aneurysm volume using an automated voxel-based volumetric method (voxel volume method) and compare results to volumes calculated by ellipsoid and cylindrical algebraic formulae (algebraic volume method). We constructed 13 latex aneurysm moulds and measured their true volumes using a micropipette in-vitro. 3D-DSA was performed on contrast filled moulds and experimental volume estimated by both voxel and algebraic methods. In our in-vivo study we quantified the voxel and algebraic volumes from the 3D data sets of 75 cerebral aneurysms. The linear regression test provided correction values between voxel and algebraic methods. The in-vitro study showed that the voxel volume method was the most accurate (mean percentage deviation from true volume 3.7 +/- 3.5%; p=0.9). The ellipsoid method significantly underestimated - 11.2 +/- 13.6%; p < 0.05) and the cylindrical method overestimated (42.6 +/- 35.7%; p < 0.05) true aneurysm volume. Similar results were obtained in-vivo. While algebraic measurements could be corrected by an equation, the clinical usefulness of this equation is questionable due to the large volume range to achieve a 95% confidence interval. The voxel volume method is accurate in quantifying aneurysm volume. Aneurysms in-vivo do not conform to simple algebraic geometry. Aneurysm volume on 3D-DSA should be calculated by the voxel-based method and not by algebraic formulae.

The pretzel sign: angiographic pattern of tortuous intra-aneurysmal blood flow in a giant serpentine aneurysm.

Giant serpentine aneurysms (GSAs) form a specific subgroup of giant cerebral aneurysms that have pathognomonic angiographic features. We report the angiographic findings of a GSA demonstrating a striking convoluted dynamic flow pattern, which we have called the 'pretzel sign'. The aneurysm was successfully treated by permanent occlusion of the parent vessel using a detachable balloon. GSAs should be identified prior to treatment in view of their particular management requirements.

Benzodiazepines inhibit the rate of neutrophil apoptosis.

BACKGROUND: Benzodiazepines, which are commonly administered perioperatively, can depress immune function. Neutrophil apoptosis plays a central role in the regulation of inflammation. This is particularly important during and after surgery. AIM: To examine the effects of benzodiazepines (midazolam and diazepam) on neutrophil apoptosis. METHODS: Venous blood samples were withdrawn from patients scheduled to undergo elective surgery, (a) immediately prior to, and 10 minutes after administration of midazolam 0.2 mg/kg intravenously (n=11) and (b) immediately prior to, and 60 minutes after administration of diazepam 10 mg p.o. (n=10). Neutrophil apoptosis was measured by Annexin V-FITC after 1 and 12 hours in culture. RESULTS: The percentage of apoptotic cells was significantly less after midazolam at 12% (11.9) hours in culture compared to pre-midazolam 29.7% (13.3) (p<0.05). After diazepam, the rates of neutrophil apoptosis were also significantly less after 12 hours in culture (p<0.05). CONCLUSION: Administration of benzodiazepines in clinically relevant doses inhibits neutrophil apoptosis. In the perioperative period, this may influence the inflammatory response to surgery.

Iodinated contrast media induce neutrophil apoptosis through a mitochondrial and caspase mediated pathway.

Iodinated contrast media (ICM) can induce apoptosis (programmed cell death) in renal, myocardial and endothelial cells. Following intravascular injection, circulating immune cells are exposed to high concentrations of ICM. As neutrophils constitutively undergo apoptosis we hypothesized that ICM may adversely affect neutrophil survival. Our aim was to investigate the effect of ICM on neutrophil apoptosis. Neutrophils were isolated from healthy subjects and cultured in vitro with ionic (diatrizoate and ioxaglate) and non-ionic (iohexol and iotrolan) ICM. The effect of ICM on neutrophil apoptosis in both unstimulated and lipopolysaccharide-stimulated neutrophils was determined by annexin V flow cytometry. The influence of physicochemical properties of the different ICM on apoptosis of neutrophils was also studied. We further investigated the effects of ICM on key intracellular signal pathways, including p38 mitogen-activated protein kinase (MAPK) by Western blotting, and mitochondrial depolarization and caspase activity by flow cytometry. Isoiodine concentrations (20 mg ml(-1)) of ionic (diatrizoate 69.6+/-2.9%; ioxaglate 58.9+/-2.0%) and non-ionic (iohexol 57.3+/-2.9%; iotrolan 57.1+/-2.6%) ICM significantly induced neutrophil apoptosis over control levels (47.7+/-1.4%). The apoptotic effect of ICM was influenced by their chemical structure, with ionic ICM having a more significant (p<0.01) apoptotic effect than non-ionic ICM (p<0.05). Furthermore, ICM reversed the anti-apoptotic effect of lipopolysaccharide (1000 ng ml(-1)) treated neutrophils to control levels (23.0+/-3.5% to 61.2+/-5.3%; n=4; p<0.05). These agents induce apoptosis through a p38 MAPK independent pathway that results in mitochondrial depolarization, and is dependent on caspase activation. As neutrophils play a central role in host response to infection and injury, ICM, through induction of neutrophil apoptosis, could have a significant deleterious effect on host immune defence and resolution of an inflammatory response.

General versus regional anaesthesia for cataract surgery: effects on neutrophil apoptosis and the postoperative pro-inflammatory state.

At clinically relevant concentrations, volatile anaesthetic agents influence neutrophil function. Our hypothesis was that sevoflurane would inhibit neutrophil apoptosis and consequently influence the postoperative pro-inflammatory state. In order to identify selectively the effect of the anaesthetic agent sevoflurane, we studied patients undergoing minimally stimulating (cataract) surgery randomly allocated to receive either sevoflurane (n = 11) or local anaesthesia (n = 12). Venous blood samples were taken immediately prior to anaesthesia and at 1, 8 and 24 h thereafter. The rate of neutrophil apoptosis, plasma concentration of cytokines and differential white cell count were measured. The rates of neutrophil apoptosis and plasma concentrations of IL-1beta, TNF-alpha and IL-8 at each time point were similar in the two groups. IL-6 concentrations increased significantly and to a similar extent compared to preanaesthetic levels at 8 and 24 h. This study demonstrates that sevoflurane does not influence the rate of neutrophil apoptosis, cytokine concentrations and neutrophil count following cataract surgery.

Inhibition of neutrophil apoptosis after elective surgery.

BACKGROUND: Neutrophils play a crucial role in host defense against infections, but their inappropriate infiltration and activation within tissues can cause host tissue damage through release of reactive oxygen metabolites, metalloproteinases, and proinflammatory cytokines. The termination of a neutrophil-mediated inflammatory response is effected through programmed cell death or apoptosis. Delayed neutrophil apoptosis is associated with proinflammatory diseases, such as the systemic inflammatory response syndrome. Surgery induces a profound inflammatory response; therefore, neutrophil apoptosis of patients undergoing elective surgery was investigated. METHODS: Nonseptic patients undergoing elective orthopedic surgery while under epidural anesthesia had neutrophils and platelet-poor isolated from whole venous blood harvested at 4 time points: pre-epidural, 45 minutes postepidural but before surgical intervention, 1 hour postsurgical incision, and 24 hours postsurgery. Neutrophil apoptosis was quantified at 1, 12, and 24 hours in culture by immunofluorescence flow cytometry of annexin V and propidium iodide staining and confirmed by TUNEL (terminal deoxynucleotidyl transferase nick end labeling) assay for DNA strand breaks. Serum cytokines were quantified by specific enzyme-linked immunosorbent assay. RESULTS: Spontaneous neutrophil apoptosis after elective surgery was significantly (P < .001) inhibited with an effect evident within an hour of surgical incision and persisting at 24 hours postsurgery. The addition of patients' 24 hour postoperative plasma to healthy neutrophils markedly (P < .01) reduced neutrophil apoptosis, whereas plasma taken an hour after surgical incision was ineffective. Interleukin (IL)-6 was notably increased (1395 +/- 196 pg/mL, P < .01) 24 hours postsurgery and at this postoperative concentration inhibited (P < .01) apoptosis of normal neutrophils. Levels of other inflammatory mediators (IL-1 beta, tumor necrosis factor alpha, granulocyte-macrophage colony-stimulating factor, soluble Fas, soluble Fas ligand) were unaltered. The anti-inflammatory cytokine IL-10 was only slightly increased 24 hours postsurgery (8.32 +/- 2.99 pg/mL); however, the addition of recombinant human IL-10 (10 ng/mL) counteracted (P < .05) inhibition of neutrophil apoptosis induced by IL-6 and post-surgery plasma. CONCLUSIONS: These results identify marked inhibition of neutrophil apoptosis after elective surgery and suggest that the inhibition of neutrophil apoptosis in the postoperative period is, at least in part, a result of soluble circulating factors. The marked imbalance favoring proinflammatory over anti-inflammatory cytokine release in the immediate postoperative period mediates the overwhelmingly antiapoptotic net capacity of postsurgery plasma.

Circulating granulocyte macrophage colony-stimulating factor in plasma of patients with the systemic inflammatory response syndrome delays neutrophil apoptosis through inhibition of spontaneous reactive oxygen species generation.

In the normal resolution of an acute inflammatory response apoptosis of neutrophils is essential to maintain immune homeostasis and limit inappropriate host tissue damage by decreasing neutrophil tissue load, function, and release of phlogistic reactive oxygen species and proteases. The systemic inflammatory response syndrome (SIRS), a massive pro-inflammatory immune state, is associated with delayed neutrophil apoptosis, however, the systemic circulating factors and intracellular signal transduction pathways important in regulating neutrophil apoptosis in SIRS are poorly described. Neutrophils isolated from patients with SIRS on admission to the intensive care unit showed significantly (p<.01) delayed spontaneous neutrophil apoptosis compared with healthy neutrophils as quantified using annexin V-FITC and terminal deoxyuridine triphosphate (dUTD) nick end labeling (TUNEL) flow cytometry methods. Plasma from SIRS patients markedly (41.5+/-7.2%, p<.01) inhibited apoptosis of healthy neutrophils compared with controls (69.7+/-4.8%) indicating the presence of soluble circulating factors that can modify the expression of neutrophil apoptosis. Various pro-inflammatory (IL-6, granulocyte macrophage colony-simulating factor, interleukin (IL)-1beta, tumor necrosis factor-alpha) mediators, known to modulate neutrophil apoptosis in vitro, were elevated in the plasma of our cohort of SIRS patients compared with controls. However, the anti-apoptotic effect of SIRS plasma was specifically attenuated (75.5%, p<.01) by neutralizing SIRS plasma of granulocyte macrophage-colony-stimulating factor, but not IL-6, IL-1beta, tumor necrosis factor-alpha. Although the anti-inflammatory cytokine IL-10 was elevated in SIRS plasma (median level 7.2 pg/mL), further boosting SIRS plasma with recombinant human IL-10 (10 ng/mL, levels found in septic shock patients) significantly countered (63.8%, p<.01) the inhibitory effect of SIRS plasma on neutrophil apoptosis. Suppression of neutrophil apoptosis was concomitant with delayed spontaneous elevation of reactive oxygen species, quantified as peroxide production, and reversed by addition of neutralizing antibodies to GM-CSF, and recombinant human IL-10 to SIRS plasma. These results identify circulating GM-CSF as a significant inhibitor of neutrophil apoptosis in patients with SIRS, and that this effect can be countered by boosting SIRS plasma with IL-10. GM-CSF and IL-10 appear to modulate neutrophil apoptosis by altering reactive oxygen species generation in neutrophils.

In-situ emergency paediatric surgery in the intensive care unit.

The role of surgery in the intensive care unit (ICU) remains unclear. Although previously shown not to increase morbidity for patent ductus arteriosus ligation, Broviac catheter insertion, and recently, general neonatal and paediatric surgery, there remains a reluctance to operate on sick patients in the ICU (in-situ surgery, ISS). A retrospective study of 25 critically ill children and neonates who underwent ISS was performed. Surgery was aided by operating loupes and a high-intensity headlight. ISS was not associated with any morbidity, and although a 36% mortality occurred in this small series, in no case was this due to ISS. ISS avoids the risks of transfer to the operating theatre and the potential delays in theatre access. Our results suggest that ISS in a tertiary-level paediatric surgical hospital is safe and does not impact adversely on clinical outcome.

Helicobacter pylori does not play a role in the aetiology of acute appendicitis.

The aetiology of acute appendicitis remains uncertain. H. pylori is viable outside the gastroduodenum, however its pathological role outside this area has not been fully investigated. Ten consecutive patients with a histological diagnosis of acute appendicitis were investigated for H. pylori status by serology, and by culture, histology, and polymerase chain reaction (PCR) analysis of the appendiceal specimens. One patient had positive serology for H. pylori, however PCR analysis was negative. Culture failed to reveal H. pylori colonies. Histology in 5 cases did reveal organisms with a morphological appearance of H. pylori, but PCR analysis confirmed that H. pylori was not present. Using a variety of methods, with PCR acting as the 'gold standard', we have shown that H. pylori is not associated with acute appendicitis.

External carotid artery ligation for life-threatening hemorrhage in exsanguinating orbital facial congenital hemangiopericytoma.

A 7-week-old infant with a locally invasive, orbital, congenital hemangiopericytoma underwent emergency external carotid artery (ECA) ligation for exsanguinating hemorrhage from an intraoral biopsy site. ECA ligation was successful in controlling the life-threatening hemorrhage and in reducing tumor size and vascularity. The location and extensive nature of the tumor prevented primary excision. Preoperative adjuvant chemotherapy was unsuccessful in controlling tumor growth. After ECA ligation, with reduction in tumor bulk and blood supply, the tumor was radically excised. This technique has important implications in the management of patients with extensive hemangiopericytomas or sino-facial tumors previously regarded as unresectable and which present with life-threatening hemorrhage.