Stereotactic radiosurgery is an effective management strategy for properly selected patients with arteriovenous malformations (AVMs). However, the risk of postradiosurgical radiation-related injury is higher in patients with large AVMs. Multistaged volumetric management of large AVMs was undertaken to limit the radiation exposure to the surrounding normal brain. This strategy offers a promising method for obtaining high AVM obliteration rates with minimal normal tissue damage. The use of embolization as an adjunctive method in the treatment of large AVMs remains controversial. Unfortunately, staged-volume radiosurgery (SVR) has a number of potential pitfalls that affect the outcome. The aim of this article is to highlight the role of SVR in the treatment of large AVMs, to discuss the outcome comparing it to other treatment modalities, and to discuss the potential improvement that could be introduced to this method of treatment.
Kenan AlKhalili, Nohra Chalouhi, Stavropoula Tjoumakaris, Robert Rosenwasser, and Pascal Jabbour
Badih Daou, Christine Hammer, Nohra Chalouhi, Robert M. Starke, Pascal Jabbour, Robert H. Rosenwasser, and Stavropoula Tjoumakaris
Dissection of the carotid and vertebral arteries can result in the development of aneurysmal dilations. These dissecting pseudoaneurysms can enlarge and cause symptoms. The objective of this study is to provide insight into the progression of dissecting pseudoaneurysms and the treatments required to manage them.
A review of the electronic medical records was conducted to detect patients with carotid and vertebral artery dissection. An imaging review was conducted to identify patients with dissecting pseudoaneurysms. One hundred twelve patients with 120 dissecting pseudoaneurysms were identified. Univariate and multivariate analyses were conducted to assess the factors associated with undergoing further interventions other than medical treatment, pseudoaneurysm enlargement, pseudoaneurysms resulting in ischemic and nonischemic symptoms, and clinical outcome.
Overall, 18.3% of pseudoaneurysms were intracranial and 81.7% were extracranial, and the average size was 7.3 mm. The mean follow-up time was 29.3 months; 3.3% of patients had a recurrent transient ischemic attack, no patients had a recurrent stroke, and 14.2% of patients had recurrence of nonischemic symptoms (headache, neck pain, Horner syndrome, or cranial nerve palsy). Follow-up imaging demonstrated that 13.8% of pseudoaneurysms had enlarged, 30.2% had healed, and 56% had remained stable. In total, 20.8% of patients had an intervention other than medical treatment. Interventions included stenting, coiling, flow diversion, and clipping. Predictors of intervention included increasing size, size > 10 mm, location in the C2 (petrous) segment of the internal carotid artery (ICA), younger age, hyperlipidemia, pseudoaneurysm enlargement, and any symptom development. Significant predictors of enlargement included smoking, history of trauma, C2 location, hyperlipidemia, and larger initial pseudoaneurysm size. Predictors of pseudoaneurysm resulting in recurrent ischemic and nonischemic symptoms included increasing size and location in the petrous segment of the ICA. Smoking was a predictor of unfavorable outcome.
Dissecting pseudoaneurysms have a benign course and most will not cause symptoms or enlarge on follow-up. Medical treatment can be a sufficient, initial treatment for dissecting pseudoaneurysms.
L. Fernando Gonzalez, Nohra Chalouhi, Stavropoula Tjoumakaris, Pascal Jabbour, Aaron S. Dumont, and Robert H. Rosenwasser
Multiple approaches have been used to treat carotid-cavernous fistulas (CCFs). The transvenous approach has become a popular and effective route. Onyx is a valuable tool in today's endovascular armamentarium. The authors describe the use of a balloon-assisted technique in the treatment of CCFs with Onyx and assess its feasibility, utility, and safety.
The authors searched their prospectively maintained database for CCFs embolized using Onyx with the assistance of a compliant balloon placed in the internal carotid artery (ICA).
Five patients were treated between July 2009 and July 2011 at the authors' institution. A balloon helped to identify the fistulous point, served as a buttress for coils, protected from inadvertent arterial embolizations, and prevented Onyx and coils from obscuring the ICA during the course of embolization. No balloon-related complications were noted in any of the 5 cases. All 5 fistulas were completely obliterated at the end of the procedure. Four patients had available clinical follow-ups, and all 4 showed reversal of nerve palsies.
Balloon-assisted Onyx embolization of CCFs offers a powerful combination that prevents inadvertent migration of the embolic material into the arterial system, facilitates visualization of the ICA, and serves as a buttress for coils deployed in the cavernous sinus through the fistulous point. Despite adding another layer of technical complexity, an intraarterial balloon can provide valuable assistance in the treatment of CCFs.
Badih Daou, Anthony P. Kent, Maria Montano, Nohra Chalouhi, Robert M. Starke, Stavropoula Tjoumakaris, Robert H. Rosenwasser, and Pascal Jabbour
Patients presenting with large-territory ischemic strokes may develop intractable cerebral edema that puts them at risk of death unless intervention is performed. The purpose of this study was to identify predictors of outcome for decompressive hemicraniectomy (DH) in ischemic stroke.
The authors conducted a retrospective electronic medical record review of 1624 patients from 2006 to 2014. Subjects were screened for DH secondary to ischemic stroke involving the middle cerebral artery, internal carotid artery, or both. Ninety-five individuals were identified. Univariate and multivariate analyses were performed for an array of clinical variables in relationship to functional outcome according to the modified Rankin Scale (mRS). Clinical outcome was assessed at 90 days and at the latest follow-up (mean duration 16.5 months).
The mean mRS score at 90 days and at the latest follow-up post-DH was 4. Good functional outcome was observed in 40% of patients at 90 days and in 48% of patient at the latest follow-up. The mortality rate at 90 days was 18% and at the last follow-up 20%. Univariate analysis identified a greater likelihood of poor functional outcome (mRS scores of 4–6) in patients with a history of stroke (OR 6.54 [95% CI1.39–30.66]; p = 0.017), peak midline shift (MLS) > 10 mm (OR 3.35 [95% CI 1.33–8.47]; p = 0.011), or a history of myocardial infarction (OR 8.95 [95% CI1.10–72.76]; p = 0.04). Multivariate analysis demonstrated elevated odds of poor functional outcome associated with a history of stroke (OR 9.14 [95% CI 1.78–47.05]; p = 0.008), MLS > 10 mm (OR 5.15 [95% CI 1.58–16.79; p = 0.007), a history of diabetes (OR 5.63 [95% CI 1.52–20.88]; p = 0.01), delayed time from onset of stroke to DH (OR 1.32 [95% CI 1.02–1.72]; p = 0.037), and evidence of pupillary dilation prior to DH (OR 4.19 [95% CI 1.06–16.51]; p = 0.04). Patients with infarction involving the dominant hemisphere had higher odds of unfavorable functional outcome at 90 days (OR 4.73 [95% CI 1.36–16.44]; p = 0.014), but at the latest follow-up, cerebral dominance was not significantly related to outcome (OR 1.63 [95% CI 0.61–4.34]; p = 0.328).
History of stroke, diabetes, myocardial infarction, peak MLS > 10 mm, increasing duration from onset of stroke to DH, and presence of pupillary dilation prior to intervention are associated with a worse functional outcome.
Elias Atallah, Hassan Saad, Kimon Bekelis, Nohra Chalouhi, Stavropoula Tjoumakaris, David Hasan, Jorge Eller, David Stidd, Robert H. Rosenwasser, and Pascal Jabbour
Thromboembolic complications continue to be encountered with Pipeline embolization devices (PEDs) despite routine clopidogrel/aspirin antiplatelet therapy. This study examined the safety and efficacy of prasugrel in the management of clopidogrel-resistant patients treated for cerebral aneurysms.
Four hundred thirty-seven consecutive patients were identified between January 2011 and May 2016. Patients allergic, or having less than 30% platelet inhibition, to a daily 75-mg dose of clopidogrel received 10 mg of prasugrel daily (n = 20) or 90 mg of ticagrelor twice daily (n = 2). The mean (± SD) follow-up duration was 15.8 ± 12.4 months. The primary outcome was the modified Rankin Scale (mRS) score registered before discharge and at each follow-up visit. To control confounding, multivariable mixed-effects logistic regression and propensity score conditioning were used.
Twenty-six (5.9%) of 437 patients presented with a subarachnoid hemorrhage (SAH). The mean patient age was 56.3 years, and 62 were women (14.2%). One of the 7 patients lost to follow-up received prasugrel. One patient was allergic to clopidogrel and prasugrel simultaneously. All patients receiving prasugrel or ticagrelor (n = 22) had an mRS score ≤ 2 on their latest follow-up visit (mean score 0.67 ± 1.15). In a multivariate analysis, clopidogrel did not affect the mRS score on last follow-up (p = 0.14). Multivariable logistic regression showed that clopidogrel was not associated with an increased long-term recurrence rate (OR 0.17, 95% CI 0.01–2.70, p = 0.21), an increased thromboembolic complication rate (OR 0.46, 95% CI 0.12–1.67, p = 0.24), or an increased hemorrhagic event rate (OR 0.39, 95% CI 0.91–1.64, p = 0.20). None of the patients receiving prasugrel or ticagrelor died or suffered a long-term recurrence or a hemorrhagic event; only 1 patient suffered from mild aphasia subsequent to a thromboembolic event. Three patients taking clopidogrel died during the study: 2 from acute SAH and 1 from intraparenchymal hemorrhage. Clopidogrel was not associated with an increased mortality rate (OR 2.18, 95% CI 0.11–43.27, p = 0.61). The same associations were present in propensity score–adjusted models.
In a cohort of patients treated with PEDs, prasugrel (10 mg/day) was a safe alternative to clopidogrel-resistant or clopidogrel-allergic patients, or nonresponders.
Nohra Chalouhi, Aaron S. Dumont, Ciro Randazzo, Stavropoula Tjoumakaris, L. Fernando Gonzalez, Robert Rosenwasser, and Pascal Jabbour
With the widespread use of brain imaging studies, neurosurgeons have seen a marked increase in the number of incidental intracranial lesions, including vascular abnormalities. Specifically, the detection of incidentally discovered aneurysms, arteriovenous malformations, cavernous angiomas, developmental venous anomalies, and capillary telangiectasias has increased. The best management strategy for most of these lesions is controversial. Treatment options include observation, open surgery, endovascular procedures, and radiosurgery. Multiple factors should be taken into account when discussing treatment indications, including the natural history of the disease and the risk of the treatment. In this article, the authors focus on the natural history of these lesions and the risk of the treatment, and they give recommendations regarding the most appropriate management strategy based on the current evidence in the literature and their experience with intracranial vascular abnormalities.
Nohra Chalouhi, Rohan Chitale, Pascal Jabbour, Stavropoula Tjoumakaris, Aaron S. Dumont, Robert Rosenwasser, and L. Fernando Gonzalez
Given that relatives of patients with intracranial aneurysms (IAs) or subarachnoid hemorrhage have a greater risk of harboring an aneurysm, family screening has become a common practice in neurosurgery. Unclear data exist regarding who should be screened and at what age and interval screening should occur. Multiple factors including the natural history of IAs, the risk of treatment, the cost of screening, and the psychosocial impact of finding an aneurysm should be taken into account when family screening is considered. In this paper, the authors review the current literature regarding risk factors and natural history of sporadic and familial aneurysms. Based on these data the authors assess current recommendations for screening and propose their own recommendations.
Shannon Hann, Nohra Chalouhi, Ravichandra Madineni, Alexander R. Vaccaro, Todd J. Albert, James Harrop, and Joshua E. Heller
Adult degenerative cervical kyphosis is a debilitating disease that often requires complex surgical management. Young spine surgeons, residents, and fellows are often confused as to which surgical approach to choose due to lack of experience, absence of a systematic method of surgical management, and today's plethora of information regarding surgical techniques. Although surgeons may be able to perform anterior, posterior, or combined (360°) approaches to the cervical spine, many struggle to rationally choose an appropriate approach for deformity correction. The authors introduce an algorithm based on morphology and pathology of adult cervical kyphosis to help the surgeon select the appropriate approach when performing cervical deformity surgery. Cervical deformities are categorized into 5 different prevalent morphological types encountered in clinical settings. A surgical approach tailored to each category/type of deformity is then discussed, with a concrete case illustration provided for each. Preoperative assessment of kyphosis, determination of the goal for surgery, and the complications associated with cervical deformity correction are also summarized. This article's goal is to assist with understanding the big picture for surgical management in cervical spinal deformity.
Ken Porche, Carolina B. Maciel, Brandon Lucke-Wold, Steven A. Robicsek, Nohra Chalouhi, Meghan Brennan, and Katharina M. Busl
Postoperative urinary retention (POUR) is a common complication after spine surgery and is associated with prolongation of hospital stay, increased hospital cost, increased rate of urinary tract infection, bladder overdistention, and autonomic dysregulation. POUR incidence following spine surgery ranges between 5.6% and 38%; no reliable prediction tool to identify those at higher risk is available, and that constitutes an important gap in the literature. The objective of this study was to develop and validate a preoperative risk model to predict the occurrence of POUR following routine elective spine surgery.
The authors conducted a retrospective chart review of consecutive adults who underwent lumbar spine surgery between June 1, 2017, and June 1, 2019. Patient characteristics, preexisting ICD-10 codes, preoperative pain and opioid use, preoperative alpha-1 blocker use, details of surgical planning, development of POUR, and management strategies were abstracted from electronic medical records. A binomial logistic model and a multilayer perceptron (MLP) were optimized using training and validation sets. The models’ performance was then evaluated on model-naïve patients (not a part of either cohort). The models were then stacked to take advantage of each model’s strengths and to avoid their weaknesses. Four additional models were developed from previously published models adjusted to include only relevant factors (i.e., factors known preoperatively and applied to the lumbar spine).
Overall, 891 patients were included in the cohort, with a mean of 59.6 ± 15.5 years of age, 52.7% male, BMI 30.4 ± 6.4, American Society of Anesthesiologists class 2.8 ± 0.6, and a mean of 5.6 ± 5.7 comorbidities. The rate of POUR was found to be 25.9%. The two models were comparable, with an area under the curve (AUC) of 0.737 for the regression model and 0.735 for the neural network. By combining the two models, an AUC of 0.753 was achieved. With a regression model probability cutoff of 0.24 and a neural network cutoff of 0.23, maximal sensitivity and specificity were achieved, with specificity 68.2%, sensitivity 72.9%, negative predictive value 88.2%, and positive predictive value 43.4%. Both models individually outperformed previously published models (AUC 0.516–0.645) when applied to the current data set.
This predictive model can be a powerful preoperative tool in predicting patients who will be likely to develop POUR. By using a combination of regression and neural network modeling, good sensitivity, specificity, and NPV are achieved.
Purvee D. Patel, Nohra Chalouhi, Elias Atallah, Stavropoula Tjoumakaris, David Hasan, Hekmat Zarzour, Robert Rosenwasser, and Pascal Jabbour
The Pipeline embolization device (PED) is the most widely used flow diverter in endovascular neurosurgery. In 2011, the device received FDA approval for the treatment of large and giant aneurysms in the internal carotid artery extending from the petrous to the superior hypophyseal segments. However, as popularity of the device grew and neurosurgeons gained more experience, its use has extended to several other indications. Some of these off-label uses include previously treated aneurysms, acutely ruptured aneurysms, small aneurysms, distal circulation aneurysms, posterior circulation aneurysms, fusiform aneurysms, dissecting aneurysms, pseudoaneurysms, and even carotid-cavernous fistulas. The authors present a literature review of the safety and efficacy of the PED in these off-label uses.