Giuseppe Lanzino and David F. Kallmes
Harry J. Cloft, Nasser Razack and David F. Kallmes
Object. The aim of this study was to determine the prevalence of cerebral saccular aneurysms in patients with persistent primitive trigeminal artery (PPTA). The prevalence of cerebral saccular aneurysms in patients with PPTA previously has been reported to be 14 to 32%, but this rate range is unreliable because it is based on collections of published case reports rather than a series of patients chosen in an unbiased manner.
Methods. The authors retrospectively evaluated their own series of 34 patients with PPTA to determine the prevalence of cerebral aneurysms in this population. The prevalence of intracranial aneurysms in patients with PPTA was approximately 3% (95% confidence interval 0–9%).
Conclusions. The prevalence of intracranial aneurysms in patients with PPTA is no greater than the prevalence of intracranial aneurysms in the general population.
Huy M. Do, Mary E. Jensen, William F. Marx and David F. Kallmes
The authors report the clinical symptoms and response to therapy of a series of patients who presented with subacute or chronic back pain due to vertebral osteonecrosis (Kümmell's spondylitis) and who underwent percutaneous vertebroplasty.
The authors performed a retrospective chart review of a series of 95 patients in whom 149 painful, nonneoplastic compression fractures were demonstrated and who were treated with percutaneous transpediculate polymethylmethacrylate (PMMA) vertebroplasty. In six of these patients there was evidence of vertebral osteonecrosis, as evidenced by the presence of an intravertebral vacuum cleft on radiography or by intravertebral fluid on magnetic resonance (MR) imaging. Clinical and radiological findings on presentation were noted. Technical aspects of the vertebroplasty technique were compiled. Response to therapy, defined as qualitative change in pain severity and change in level of activity, was noted immediately following the procedure and at various periods on follow-up reviews.
One man and five women, who ranged in age from 72 to 90 years (mean 81 years), were treated. Each patient had one compression fracture. The fractures were at T-11 (one patient), L-1 (two patients), L-3 (two patients), and L-4 (one patient). The pain pattern was described as severe and localized to the affected vertebra, and sometimes radiated along either flank. Pain duration ranged from 2 to 12 weeks, and the pain was refractory to conservative therapy that consisted of bedrest, analgesics, and external bracing. At the time of treatment, all patients were bedridden because of severe back pain. In all patients either plain radiographic or computerized tomography evidence of intravertebral vacuum cleft or MR imaging evidence of vertebral fluid collection consistent with avascular necrosis of the vertebral body was demonstrated. Four patients underwent bilateral transpediculate vertebroplasty, and two patients underwent unilateral transpediculate vertebroplasty. The fracture cavities were specifically targeted for PMMA injection. Additional fortification of the osteoporotic vertebral body trabeculae was also performed when feasible. "Cavitygrams" or intraosseous venograms with gentle contrast injection were obtained prior to application of cement mixture. In all patients subjective improvement in pain and increased mobility were demonstrated posttreatment. The follow-up period ranged from 4 to 24 hours after treatment. Two patients made additional office visits at 1 and 3 months, respectively.
Patients presenting with vertebral osteonecrosis (Kümmell's spondylitis) often suffer from local paraspinous or referred pain. When performing vertebroplasty on these patients, confirmation of entry into the fracture cavities with contrast-enhanced "cavitygrams" should be performed prior to injection of PMMA cement. The response to vertebroplasty with regard to amelioration of pain and improved mobility is encouraging.
Robert J. McDonald, Harry J. Cloft and David F. Kallmes
The authors sought to identify the presence of a “July effect,” a transient increase in adverse outcomes during July, among a cohort of spontaneous subarachnoid hemorrhage (SAH) admissions recorded in the National Inpatient Sample (NIS).
The discharge status, admission month, patient demographics, treatment parameters, and hospital characteristics among spontaneous SAH admissions were extracted from the 2001–2008 NIS. Multivariate regression was used to determine whether an unfavorable discharge status and/or in-hospital mortality significantly increased in summer months in a pattern suggestive of a July effect. Additional models were generated to assess the impact of hospital teaching status on these outcomes.
Among 57,663,486 hospital admissions from the 2001–2008 NIS, 52,879 cases of spontaneous SAH (ICD-9-CM 430) were treated at teaching (36,914 cases [70%]) and nonteaching (15,965 cases [30%]) facilities. Regression models failed to reveal a July effect for in-hospital mortality (χ2 = 0.75, p = 1.000) or unfavorable discharges (χ2 = 1.69, p = 0.999) among monthly SAH admissions, although they did suggest a significant reduction in these outcomes (in-hospital mortality, OR = 0.89, p < 0.001; unfavorable discharges, OR = 0.88, p < 0.001) among teaching hospitals as compared with nonteaching hospitals after adjustment for disparities in demographic, treatment, and hospital characteristics.
The discharge disposition among SAH admissions within the NIS was not suggestive of a July effect but did reveal that teaching institutions have significantly lower rates of adverse outcomes when compared with nonteaching hospitals. Note, however, that the origins of this difference related to teaching status remain unclear.
Caleb B. Leake, Waleed Brinjikji, David F. Kallmes and Harry J. Cloft
Evidence of better outcomes in patients with aneurysmal subarachnoid hemorrhage treated at higher-volume centers might be expected to result in more of these patients being referred to such centers. The authors evaluated the US National Inpatient Sample for the years 2001 to 2008 for trends in patient admissions for the treatment of ruptured aneurysms at high- and low-volume centers.
The authors determined the number of ruptured aneurysms treated with clipping or coiling annually at low-volume (≤ 20 patients/year) and high-volume (> 20 patients/year) centers and also counted the number of high- and low-volume centers performing each treatment. Hospitalizations for clipping or coiling ruptured aneurysms were identified by cross-matching International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes for the diagnosis of a ruptured aneurysm (ICD-9-CM 430) with procedure codes for clipping (ICD-9-CM 39.51) or coiling (ICD-9-CM 39.52, 39.79, or 39.72) cerebral aneurysms.
In 2001, 31% (435 of 1392) of the patients who underwent clipping and 0% (0 of 122 patients) of those who underwent coiling did so at high-volume centers, whereas in 2008 these numbers increased to 62% (627 of 1016) and 68% (917 of 1351) of patients, respectively. For clipping procedures, the number of low-volume centers significantly declined from 177 in 2001 to 85 in 2008, whereas the number of high-volume centers remained constant at 13–15. For coiling procedures, the number of low-volume centers decreased from 62 in 2001 to 54 in 2008, whereas the number of high-volume centers substantially increased from 0 in 2001 to 16 in 2005 and remained constant thereafter.
The treatment of ruptured cerebral aneurysms increasingly occurs at high-volume centers in the US. This trend is favorable given that better outcomes are associated with the treatment of these lesions at high-volume centers.
Ross C. Puffer, David F. Kallmes, Harry J. Cloft and Giuseppe Lanzino
In this study the authors determined the patency rate of the ophthalmic artery (OphA) after placement of 1 or more flow diversion devices across the arterial inlet for treatment of proximal internal carotid artery (ICA) aneurysms, and correlated possible risk factors for OphA occlusion.
Nineteen consecutive patients were identified (mean age 53.9 years, range 23–74 years, all female) who were treated for 20 ICA aneurysms. In all patients a Pipeline Embolization Device (PED) was placed across the ostium of the OphA while treating the target aneurysm. Flow through the OphA after PED placement was determined by immediate angiography as well as follow-up angiograms (mean 8.7 months), compared with the baseline study. Potential risk factors for OphA occlusion, including age, immediate angiographic flow through the ophthalmic branch, status of flow within the aneurysm after placement of PEDs, whether the ophthalmic branch originated from the aneurysm dome, and number of PEDs placed across the ophthalmic branch inlet were correlated with patency rate.
Patients were treated with 1–3 PEDs (3 aneurysms treated with placement of 1 PED, 12 with 2 PEDs, and 5 with 3 PEDs). In 17 (85%) of 20 treated aneurysms, no changes in the OphA flow were noted immediately after placement of the device. Two (10%) of 20 patients had delayed antegrade filling immediately following PED placement and 1 patient (5%) had retrograde flow from collaterals to the OphA immediately after placement of the device. One patient (5%) experienced delayed asymptomatic ICA occlusion; this patient was excluded from analysis at follow-up. At follow-up the OphA remained patent with normal antegrade flow in 13 (68%) of 19 patients, patent but with slow antegrade flow in 2 patients (11%), and was occluded in 4 patients (21%). No visual changes or clinical symptoms developed in patients with OphA flow compromise. The mean number of PEDs in the patients with occluded OphAs or change in flow at angiographic follow-up was 2.4 (SEM 0.2) compared with 1.9 (SEM 0.18) in the patients with no change in OphA flow (p = 0.09). There was no significant difference between the patients with occluded OphAs compared with nonoccluded branches based on patient age, immediate angiographic flow through the ophthalmic branch, status of flow through the aneurysm after placement of PEDs, whether the ophthalmic branch originated from the aneurysm dome, or number of PEDs placed across the ophthalmic branch inlet.
Approximately one-quarter of OphAs will undergo proximal thrombosis when covered with flow diversion devices. Even though these events were well-tolerated clinically, our findings suggest that coverage of branch arteries that have adequate collateral circulation may lead to spontaneous occlusion of those branches.
Jennifer S. McDonald, Michelle J. Clarke, Gregory A. Helm and David F. Kallmes
The presence of a “July effect,” where the influx of new residents and fellows at teaching hospitals every July may negatively affect patient care and outcomes, is widely debated. The authors used the Nationwide Inpatient Sample (NIS) to identify all cases of spinal surgery and examine outcomes among patients who underwent surgery in July compared with those who underwent surgery in other months.
Spinal surgery hospitalizations from 2001 to 2008 were identified in the NIS by extracting relevant ICD-9 codes. Rates of in-hospital mortality, discharge to a long-term care facility, and postoperative complications were compared between admission months and between teaching and nonteaching hospitals using the Wilcoxon rank-sum test, Fisher exact test, and multivariate regression analysis.
Compared with patients admitted in other months, patients who were admitted to teaching hospitals in July for spinal surgery showed a similar likelihood of in-hospital mortality (OR 0.94 [95% CI 0.78–1.11], p = 0.46), reaction to implanted device/instrumentation (OR 0.88 [95% CI 0.77–1.02], p = 0.09), and postoperative wound dehiscence (OR 1.12 [95% CI 0.94–1.33], p = 0.25). A significantly higher likelihood of discharge to a long-term care facility (OR 1.03 [95% CI 1.00–1.07], p = 0.0467) and postoperative infection (OR 1.11 [95% CI 1.05–1.17], p = 0.0341) was observed in teaching hospitals in July compared with other months; however, incidence rates were similar regardless of admission month. Higher-risk patients (Charlson score ≥ 2) admitted to teaching hospitals in July had a similar likelihood of all outcomes regardless of admission month.
This study of nationwide hospitalizations demonstrates that the influx of new residents and fellows in July has a negligible effect on periprocedural outcomes following spinal surgery.
Waleed Brinjikji, David F. Kallmes, Harry J. Cloft and Giuseppe Lanzino
The association between age and outcomes following aneurysm treatment with flow diverters such as the Pipeline Embolization Device (PED) have not been well established. Using the International Retrospective Study of the Pipeline Embolization Device (IntrePED) registry, the authors assessed the age-related clinical outcomes of patients undergoing aneurysm embolization with the PED.
Patients with unruptured aneurysms in the IntrePED registry were divided into 4 age groups: ≤ 50, 51–60, 61–70, and > 70 years old. The rates of the following postoperative complications were compared between age groups using chi-square tests: spontaneous rupture, intracranial hemorrhage (ICH), ischemic stroke, parent artery stenosis, cranial neuropathy, neurological morbidity, neurological mortality, combined neurological morbidity and mortality, and all-cause mortality. The association between age and these complications was tested in a multivariate logistic regression analysis adjusted for sex, number of PEDs, and aneurysm size, location, and type.
Seven hundred eleven patients with 820 unruptured aneurysms were included in this study. Univariate analysis demonstrated no significant difference in ICH rates across age groups (lowest 1.0% for patients ≤ 50 years old and highest 5.0% for patients > 70 years old, p = 0.097). There was no difference in ischemic stroke rates (lowest 3.6% for patients ≤ 50 years old and highest 6.0% for patients 50–60 years old, p = 0.73). Age > 70 years old was associated with higher rates of neurological mortality; patients > 70 years old had neurological mortality rates of 7.4% compared with 3.3% for patients 61–70 years old, 2.7% for patients 51–60 years old, and 0.5% for patients ≤ 50 years old (p = 0.006). On multivariate logistic regression analysis, increasing age was associated with higher odds of combined neurological morbidity and mortality (odds ratio 1.02, 95% confidence interval 1.00–1.05; p = 0.03).
Increasing age is associated with higher neurological morbidity and mortality after Pipeline embolization of intracranial aneurysms. However, the overall complication rates of PED treatment in this group of highly selected elderly patients (> 70 years) were acceptably low, suggesting that age alone should not be considered an exclusion criterion when considering treatment of intracranial aneurysms with the PED.
Ross C. Puffer, David J. Daniels, David F. Kallmes, Harry J. Cloft and Giuseppe Lanzino
The authors conducted a study to review their experience with tentorial dural arteriovenous fistulas (DAVFs) treated with transarterial endovascular embolization in which Onyx was used.
The authors reviewed prospectively collected data in 9 patients with tentorial DAVFs treated with Onyx embolization between 2008 and 2011. Information reviewed included clinical presentation, angiographic features, treatment, and clinical and radiologically documented outcome. Clinical follow-up was available in every patient. Radiological follow-up studies were available in 8 of 9 patients (mean follow-up 4.6 months).
Six of 9 patients had complete angiographic obliteration (in 5 this was confirmed by a follow-up angiogram obtained 3–6 months later), and 2 patients had near-complete obliteration (faint filling of the venous drainage in the late venous phase). One patient had partial obliteration and required surgical disconnection. In all patients with complete obliteration, transarterial embolization was performed through the posterior branch of the middle meningeal artery. There were no procedural complications, and no morbidity or mortality resulted from Onyx embolization.
Transarterial Onyx embolization is a valid, effective, and safe alternative to surgical disconnection in many patients with tentorial DAVFs. The presence of an adequate posterior branch of the middle meningeal artery is critical to achieve a microcatheter position distal enough to increase the likelihood of complete obliteration.