Chengyuan Wu

Contributing factors to surgical site infections.

&NA; Surgical site infections (SSIs) are the most common nosocomial infections. These complications lead to revision surgery, delayed wound healing, increased use of antibiotics, and increased length of hospital stay, all of which have a significant impact on patients and the cost of health care. Such intraoperative factors as proper skin preparation, adherence to sterile technique, surgical duration, and traffic in the operating room contribute more to SSIs than do patient‐related risk factors such as diabetes mellitus, obesity, and preexisting colonization with methicillin‐resistant Staphylococcus aureus. Surgeons have a responsibility to understand the current evidence regarding the factors that affect the rates of SSIs so as to provide the highest level of patient care.

Laser interstitial thermal therapy for medically intractable mesial temporal lobe epilepsy

To describe mesial temporal lobe ablated volumes, verbal memory, and surgical outcomes in patients with medically intractable mesial temporal lobe epilepsy (mTLE) treated with magnetic resonance imaging (MRI)–guided stereotactic laser interstitial thermal therapy (LiTT).

Coiling of Large and Giant Aneurysms: Complications and Long-Term Results of 334 Cases

The long-term complications of coil treatment of giant intracranial aneurysms were assessed in 334 instances when treatment consisted of only coiling (225), stent-assisted coiling (88), parent vessel occlusion (14), or balloon-assisted coiling (7). The authors concluded that coiling of large and giant aneurysms has reasonable safety profiles with good clinical outcomes, but aneurysm reopening was common. Stent-assisted coiling had lower recurrence, retreatment, and new or recurrent hemorrhage rates with no additional morbidity compared with conventional coiling. Aneurysm size was a major determinant of recanalization, retreatment, new or recurrent hemorrhage, and poor outcome. BACKGROUND AND PURPOSE: Large and giant intracranial aneurysms are increasingly treated with endovascular techniques. The goal of this study was to retrospectively analyze the complications and long-term results of coiling in large and giant aneurysms (≥10 mm) and identify predictors of outcome. MATERIALS AND METHODS: A total of 334 large or giant aneurysms (≥10 mm) were coiled in our institution between 2004 and 2011. Medical charts and imaging studies were reviewed to determine baseline characteristics, procedural complications, and clinical/angiographic outcomes. Aneurysm size was 15 mm on average. Two hundred twenty-five aneurysms were treated with conventional coiling; 88, with stent-assisted coiling; 14, with parent vessel occlusion; and 7, with balloon-assisted coiling. RESULTS: Complications occurred in 10.5% of patients, with 1 death (0.3%). Aneurysm location and ruptured aneurysms predicted complications. Angiographic follow-up was available for 84% of patients at 25.4 months on average. Recanalization and retreatment rates were 39% and 33%, respectively. Larger aneurysm size, increasing follow-up time, conventional coiling, and aneurysm location predicted both recurrence and retreatment. The annual rebleeding rate was 1.9%. Larger aneurysm size, increasing follow-up time, and aneurysm location predicted new or recurrent hemorrhage. Favorable outcomes occurred in 92% of patients. Larger aneurysm size, poor Hunt and Hess grades, and new or recurrent hemorrhage predicted poor outcome. CONCLUSIONS: Coiling of large and giant aneurysms has a reasonable safety profile with good clinical outcomes, but aneurysm reopening remains very common. Stent-assisted coiling has lower recurrence, retreatment, and new or recurrent hemorrhage rates with no additional morbidity compared with conventional coiling. Aneurysm size was a major determinant of recanalization, retreatment, new or recurrent hemorrhage, and poor outcome.

Neurostimulation for the treatment of epilepsy: a review of current surgical interventions.

Objectives:  Epilepsy continues to provide challenges to clinicians, as a significant proportion of patients continue to suffer from seizures despite medical and surgical treatments. Neurostimulation has emerged as a new treatment modality that has the potential to improve quality of life and occasionally be curative for patients with medically refractory epilepsy who are not surgical candidates. In order to continue to advance the frontier of this field, it is imperative to have a firm grasp of the current body of knowledge.

A Single Pipeline Embolization Device is Sufficient for Treatment of Intracranial Aneurysms

BACKGROUND AND PURPOSE: The Pipeline Embolization Device has emerged as an important treatment option for intracranial aneurysms. The number of devices needed to treat an aneurysm is uncertain and is the subject of vigorous debate. The purpose of this study was to compare rates of complications, aneurysm occlusion, and outcome in patients treated with a single-versus-multiple Pipeline Embolization Devices. MATERIAL AND METHODS: One hundred seventy-eight patients were treated with the Pipeline Embolization Device at our institution. Patients were divided into 2 groups: a single-device group (n = 126) and a multiple-device group (n = 52). RESULTS: There was no statistically significant difference between the 2 groups with respect to baseline characteristics except for age and aneurysm size (higher with multiple Pipeline Embolization Devices). Complications occurred more frequently with multiple (15%) versus a single device (5%, P = .03). In multivariate analysis, the use of multiple devices independently predicted complications. A similar proportion of patients achieved adequate aneurysm obliteration at follow-up in the single-device (84%) and the multiple-device groups (87%, P = .8). In multivariate analysis, age and follow-up time predicted obliteration. At follow-up, a significantly higher proportion of patients treated with a single device (97%) achieved a favorable outcome compared with those treated with multiple devices (89%, P = .03). In multivariate analysis, there was a strong trend for the use of a single device to predict favorable outcomes (P = .06). CONCLUSIONS: Treatment with a single Pipeline Embolization Device provides similar occlusion rates with less complications and better overall outcomes. These findings suggest that a single Pipeline Embolization Device is sufficient for treatment of most intracranial aneurysms.

Endovascular management of cerebral vasospasm following aneurysm rupture: Outcomes and predictors in 116 patients

OBJECTIVE To retrospectively assess the safety and efficacy of endovascular treatment of cerebral vasospasm with different modalities and assess predictors of outcome. METHODS Endovascular treatment was indicated in the event of neurological deterioration refractory to medical therapy. Data were collected for 116 patients treated at our institution. RESULTS Vasospasm was treated with balloon angioplasty in 52.6%, intra-arterial nicardipine infusion in 19.8%, or both in 27.6%. Angiographic vasospasm was reversed in all but 4 (96.6%) patients. The complication rate was 0.9%. Twenty patients (17.2%) had incipient pre-procedure hypodensities; 3 (15%) hypodensities were reversed and neurological improvement occurred in 60% of these patients. Retreatment was required in 22 (19%) patients. Higher Hunt and Hess grades and treatment with nicardipine alone predicted retreatment. Neurological improvement was noted in 82%. Male gender, pre-procedure hypodensities, and posterior communicating artery aneurysm location negatively predicted neurological recovery. Favorable outcomes were noted in 73%. Higher Hunt and Hess grades, pre-procedure hypodensities, posterior circulation aneurysms, and no neurological recovery predicted poor outcome. CONCLUSION Endovascular therapy for vasospasm has an excellent safety-efficacy profile. Balloon angioplasty and nicardipine are equally effective but effects of nicardipine are less durable. Patients with incipient pre-procedure hypodensities benefit from endovascular intervention and should probably not be excluded from treatment.

Complications of subdural and depth electrodes in 269 patients undergoing 317 procedures for invasive monitoring in epilepsy

Intracranial monitoring is fundamental to epilepsy surgery, with reported complication rates of 3–17%. We aimed to assess the differences in complication rates between subdural and depth electrodes.

The effects of anatomic variations on stereotactic laser amygdalohippocampectomy and a proposed protocol for trajectory planning.

BACKGROUND: Stereotactic laser amygdalohippocampectomy (SLAH) is a promising minimally invasive alternative for mesial temporal lobe epilepsy. As seizure outcome has been associated with the extent of amygdalar and hippocampal ablation, it is important to select a safe trajectory optimizing involvement of both structures; however, variations in temporal anatomy significantly affect the overall complexity of planning. OBJECTIVE: To quantify anatomic variables of SLAH and facilitate stereotactic planning by developing a protocol for optimally targeting the amygdalohippocampal complex (AHC). METHODS: We performed a retrospective analysis of 19 SLAHs. Anatomic measurements from preoperative magnetic resonance imaging and laser trajectory measurements from coregistered postoperative magnetic resonance imaging were taken in 11 patients. Simple linear regression analysis was performed to identify significant predictor variables determining ablation extent. Based on these data, a protocol for optimal trajectory planning was developed and subsequently implemented in 8 patients. RESULTS: The medial angle of the laser trajectory correlated with the medial angle of the AHC. The length of amygdalar cannulation was predictive of its ablation volume. All trajectories passed through a posteroinferior corridor formed by the lateral ventricle superiorly and collateral sulcus inferiorly. Our protocol facilitated planning and increased the volume of AHC ablation. CONCLUSION: The medial AHC angle dictates the medial trajectory angle and a path from the posteroinferior corridor through the hippocampus and the center of the amygdala dictates the caudal angle. These observations led to a protocol for long-axis AHC cannulation that maintains an extraventricular trajectory to minimize hemorrhage risk and targets the center of the amygdala to optimize ablation volumes. ABBREVIATIONS: AHC, amygdalohippocampal complex MTLE, mesial temporal lobe epilepsy SLAH, stereotactic laser amygdalohippocampectomy

Widening and High Inclination of the Middle Cerebral Artery Bifurcation Are Associated With Presence of Aneurysms

Background and Purpose— The middle cerebral artery (MCA) bifurcation is a preferred site for aneurysm formation. Wider bifurcation angles have been correlated with increased risk of aneurysm formation. We hypothesized a link between the presence of MCA aneurysms and the angle morphology of the bifurcation. Methods— Three-dimensional rotational angiography volumes of 146 MCA bifurcations (62 aneurysmal) were evaluated for angle morphology: parent–daughter angles (larger daughter Ф1, smaller daughter Ф2), bifurcation angle (Ф1+Ф2), and inclination angle (&ggr;) between the parent vessel axis and the plane determined by daughter vessel axes. Statistics were evaluated using Wilcoxon rank-sum analysis and area under the receiver operator characteristic curve. Results— Aneurysmal bifurcations had wider inclination angle &ggr; (median 57.8° versus 15.4°; P<0.0001). Seventy-five percent of aneurysmal MCAs had &ggr; >10°, compared with 25% nonaneurysmal. Ф1 and Ф2, but especially Ф1+Ф2, were significantly larger in aneurysmal bifurcations (median 171.3° versus 98.1°; P<0.0001). Sixty-seven percent of aneurysmal bifurcations had Ф1+Ф2 >161°, compared with 0% nonaneurysmal MCAs. An optimal threshold of 140° was established for Ф1+Ф2 (area under the curve, 0.98). Sixty-eight percent of aneurysms originated off the daughter branches. Seventy-six percent of them originated off the branch with the largest branching angle, specifically if this was the smaller daughter branch. Wider Ф1+Ф2 correlated with aneurysm neck width, but not dome size. Conclusions— MCA bifurcations harboring aneurysms have significantly larger branching angles and more often originate off the branch with the largest angle. Wider inclination angle is strongly correlated with aneurysm presence, a novel finding. The results point to altered wall shear stress regulation as a possible factor in aneurysm development and progression.

Impedance Variations over Time for a Closed‐Loop Neurostimulation Device: Early Experience with Chronically Implanted Electrodes

Responsive neurostimulation (RNS®) is an investigational treatment modality for intractable focal epilepsy. We analyzed impedance values over time to gain a better understanding of RNS device stability, potential differences between depth and strip electrodes, and general implications of long‐term electrode implantation.