Endovascular coil embolization of intracranial aneurysms: important factors related to rates and outcomes of incomplete occlusion

OBJECT: The authors report on important factors that influenced clinical and angiographically demonstrated outcomes in patients treated using coil embolization. METHODS: This study included 160 consecutive patients who underwent endovascular coil embolization for treatment of intracranial aneurysms. Univariate and multivariate logistic regression analyses were performed to assess factors that influenced the immediate posttreatment angiographic result. Cox regression analysis was used to establish factors related to the occurrence of negative events as well as a curve indicating the time to a negative event. Negative events were defined as aneurysm remnant increase, repeated treatment, rebleeding, or death during periprocedural hospitalization. Seventy-three percent of the patients treated in this study were independent or demonstrated no deficit (Glasgow Outcome Scale [GOS] Score 4 or 5) at a mean follow up of 18.2 months. The annual delayed rebleeding rate was 0.45%. Fifty percent of patients (65 of 131) suffered a negative event within 13 +/- 14 months (standard deviation). Statistically significant factors associated with the occurrence of negative events were rupture status (p = 0.0128) and immediate posttreatment angiographic result (p < 0.001). Overall clinical outcome assessed using the GOS was significantly related to the immediate posttreatment angiographic result (chi2 = 4.788, p = 0.029). The immediate post-treatment angiographic results were significantly influenced by catheter stability (p = 0.0012), aneurysm geometry (that is, simple or complex, p = 0.0053), and aneurysm neck diameter (p = 0.0205). CONCLUSIONS: A good or excellent clinical outcome can be obtained in most patients treated using endovascular coil embolization of intracranial aneurysms. Note, however, that a significant number of patients treated using traditional platinum coils will harbor unstable aneurysm remnants or require repeated treatment.     

Axillary nodal metastasis and resection margins as predictors of Loco Regional Recurrence in Breast Cancer Patients

BackgroundSurgical resection margins (RM), axillary nodal involvement and lymph node ratio (LNR) determine loco-regional control (LRC) in breast cancer management. Late presentation precludes breast conservation therefore surgical option is usually mastectomy and adjuvant chemoradiation minimize loco-regional recurrence (LRR).ObjectiveWe investigated the prognostic role of lymph nodes positive for malignancy (pN), LNR and RM on LRR of breast cancer in a tertiary hospital in Ibadan, Nigeria.MethodsLongitudinal cohort study of 225 females with breast carcinoma managed and followed up for 5-years with end point of LRR or not. Chi-square test and logistic regression analysis were used to evaluate the interaction of resection margin and proportion of metastatic lymph nodes with LRR. The receiver-operator curve was plotted to determine the proportion of metastatic lymph nodes which predicted LRR.ResultsNinety-nine percent had modified radical mastectomy and 163 (72.4%) had negative resection margins. A mean of 11 axillary lymph nodes were harvested at surgery. The age, positive resection margin and number of harvested nodes with malignant cells are associated with LRR. The overall 5-year LRR rate was 16%.ConclusionLRR is dependent on lymph node involvement as well as and tumor aggressiveness.     

Long-Term Performance of Endocardial Leads with Steroid-Eluting Electrodes

During a three-year period, 48 steroid-eluting leads (Medtronic* 4003 and 4503] have been implanted in 39 patients. 23 were implanted in the atrium and 25 in the ventricle. 36 patients with 45 leads have been observed for more than 12 months. Stimulation thresholds have been followed using pulse generators with variable output (vario): 12 atrial and 11 ventricular leads, 4 atrial leads and 11 ventricular leads have been followed using pulse generators with variable pulse-width (auto-threshold], P-waves have been followed using telemetry or sensitivity programming (23 atrial leads). R-waves have been followed using telemetry in 11 ventricular leads. Mean stimulation thresholds after 2 years are 0.7 V ± 0.2 in the atrium and 0.8 V ± 0.3 in the ventricle. P-waves after 2 years are of magnitudes allowing a sensitivity setting of 2.5 mV in 12 cases and of 1.5 mV in 2 cases; R-waves have in all cases been high enough to permit lowest programmable sensitivity setting. During the observation time, two patients have died from nonpacing-related causes. The results obtained from this investigation document low stimulation thresholds and good sensing levels in both ventricle and atrium using the steroid-eluting electrode with no significant changes after 6 weeks postimplant.     

Clinical Evaluation of Atrial Synchronous Ventricular Inhibited Pacemakers

The technical specifications and the operation of two atrial synchronous ventricular inhibited (ASVIP) pacemaker designs are described along with the results of clinical evaluation of these pacemakers in 30 patients. Clinical advantages of such pacemakers are contrasted with the performance of A-V sequential (DVI) and atrial synchronous (VAT) systems.     

Acute and Long-Term Atrial and Ventricular Stimulation Thresholds with a Steroid-Eluting Electrode

Thirty leads with a steroid-eluting electrode (Medtronic 4003 and 4503) have been implanted in 24 patients, 11 in the atrium and 19 in the ventricle. Six patients received the steroid lead in both atrium and ventricle. The stimulation thresholds were followed using Elema pulse generators with Vario function in 15 patients (11 atrial leads and 10 ventricular leads) during 11 +/- 3 months (mean +/- SD). At 0.5 ms pulse duration the mean atrial and ventricular thresholds were 0.55 Volt +/- 0.22 and 0.39 Volt +/- 0.22 respectively at implant, 0.94 Volt +/- 0.13 and 0.82 Volt +/- 0.16 after 12 months. During the entire follow-up period both atrial and ventricular mean thresholds never exceeded 1 V.     

Comparison of maximum intensity projection and digitally reconstructed radiographic projection for carotid artery stenosis measurement

Digital subtraction angiography is being supplanted by three-dimensional imaging techniques in many clinical applications, leading to extensive use of maximum intensity projection (MIP) images to depict volumetric vascular data. The MIP algorithm produces intensity profiles that are different than conventional angiograms, and can also increase the vessel-to-tissue contrast-to-noise ratio. We evaluated the effect of the MIP algorithm in a clinical application where quantitative vessel measurement is important: internal carotid artery stenosis grading. Three-dimensional computed rotational angiography (CRA) was performed on 26 consecutive symptomatic patients to verify an internal carotid artery stenosis originally found using duplex ultrasound. These volumes of data were visualized using two different postprocessing projection techniques: MIP and digitally reconstructed radiographic (DRR) projection. A DRR is a radiographic image simulating a conventional digitally subtracted angiogram, but it is derived computationally from the same CRA dataset as the MIP. By visualizing a single volume with two different projection techniques, the postprocessing effect of the MIP algorithm is isolated. Vessel measurements were made, according to the NASCET guidelines, and percentage stenosis grades were calculated. The paired t-test was used to determine if the measurement difference between the two techniques was statistically significant. The CRA technique provided an isotropic voxel spacing of 0.38 mm. The MIPs and DRRs had a mean signal-difference-to-noise-ratio of 30:1 and 26:1, respectively. Vessel measurements from MIPs were, on average, 0.17 mm larger than those from DRRs (P < 0.0001). The NASCET-type stenosis grades tended to be underestimated on average by 2.4% with the MIP algorithm, although this was not statistically significant (P=0.09). The mean interobserver variability (standard deviation) of both the MIP and DRR images was 0.35 mm. It was concluded that the MIP algorithm slightly increased the apparent dimensions of the arteries, when applied to these intra-arterial CRA images. This subpixel increase was smaller than both the voxel size and interobserver variability, and was therefore not clinically relevant.