Thomas J. Buell, Davis G. Taylor, Ching-Jen Chen, and Bhiken I. Naik
Ching-Jen Chen, Dwight Saulle, Kai-Ming Fu, Justin S. Smith, and Christopher I. Shaffrey
This study was undertaken to evaluate the incidence of and risk factors associated with the development of dysphagia following same-day combined anterior-posterior cervical spine surgeries.
The records of 30 consecutive patients who underwent same-day combined anterior-posterior cervical spine surgery were reviewed. The presence of dysphagia was assessed by a formalized screening protocol using history/clinical presentation and a bedside swallowing test, followed by formal evaluation by speech and language pathologists and/or fiberoptic endoscopic evaluation of swallowing/modified barium swallow when necessary. Age, sex, previous cervical surgeries, diagnoses, duration of procedure, specific vertebral levels and number of levels operated on, degree of sagittal curve correction, use of anterior plate, estimated blood loss, use of recombinant human bone morphogenetic protein-2 (rhBMP-2), and length of hospital stay following procedures were analyzed.
In the immediate postoperative period, 13 patients (43.3%) developed dysphagia. Outpatient follow-up data were available for 11 patients with dysphagia, and within this subset, all cases of dysphagia resolved subjectively within 12 months following surgery. The mean numbers of anterior levels surgically treated in patients with and without dysphagia were 5.1 and 4.0, respectively (p = 0.004). All patients (100%) with dysphagia had an anterior procedure that extended above C-4, compared with 58.8% of patients without dysphagia (p = 0.010). Patients with dysphagia had significantly greater mean correction of C2–7 lordosis than patients without dysphagia (p = 0.020). The postoperative sagittal occiput–C2 angle and the change in this angle were not significantly associated with the occurrence of dysphagia (p = 0.530 and p = 0.711, respectively). Patients with postoperative dysphagia had significantly longer hospital stays than those who did not develop dysphagia (p = 0.004). No other significant difference between the dysphagia and no-dysphagia groups was identified; differences with respect to history of previous anterior cervical surgery (p = 0.141), use of an anterior plate (p = 0.613), and mean length of anterior cervical operative time (p = 0.541) were not significant.
The incidence of dysphagia following combined anterior-posterior cervical surgery in this study was comparable to that of previous reports. The risk factors for dysphagia that were identified in this study were increased number of anterior levels exposed, anterior surgery that extended above C-4, and increased surgical correction of C2–7 lordosis.
Panagiotis Mastorakos, Davis G. Taylor, Ching-Jen Chen, Thomas Buell, Joseph H. Donahue, and John A. Jane Jr.
Cavernous sinus invasion (CSI) in Cushing’s disease (CD) negatively affects the probability of complete resection, biochemical cure, and need for adjuvant therapy. However, the prediction of CSI based on MRI findings has been inconsistent and variable. Among macroadenomas, the Knosp classification is the most widely utilized radiographic predictor of CSI, but its accuracy in predicting CSI and the probability of gross-total resection is limited in the setting of microadenomas or Knosp grade 0–2 macroadenomas. The authors noticed that the presence of a triangular shape of adenomas adjacent to the cavernous sinus on coronal MR images is frequently associated with CSI. The authors aimed to determine the correlation of this radiographic finding (“sail sign” [SS]) with CSI.
The authors performed a retrospective review of all patients with a pituitary lesion < 20 mm and a biochemical diagnosis of CD treated with endoscopic or microscopic transsphenoidal resection from November 2007 to May 2017. Overall 185 patients with CD were identified: 27 were excluded for negative preoperative imaging, 32 for lacking tumors adjacent to the sinus, 7 for Knosp grade 3 or higher, and 4 for inadequate intraoperative assessment of the CSI. Following application of inclusion and exclusion criteria, 115 cases were available for statistical analysis. Intraoperative CSI was prospectively evaluated at the time of surgery by one of two neurosurgical attending surgeons, and MRI data were evaluated retrospectively by a neurosurgical resident and attending neuroradiologist blinded to the intraoperative results.
A positive SS was identified in 23 patients (20%). Among patients with positive SS, 91% demonstrated CSI compared to 10% without an SS (p < 0.001). Using the SS as a predictor of CSI provided a sensitivity of 0.7 and a specificity of 0.98, with a positive predictive value (PPV) of 0.91 and a negative predictive value of 0.9. Among patients with positive SS, 30% did not achieve immediate postoperative remission, compared to 3.3% of patients without an SS (p < 0.001).
The presence of a positive SS among Cushing’s adenomas adjacent to the CS provides strong PPV, specificity, and positive likelihood ratio for the prediction of CSI. This can be a useful tool for preoperative planning and for predicting the likelihood of long-term biochemical remission and the need for adjuvant radiosurgery.
Thomas J. Buell, Daniel M. S. Raper, I. Jonathan Pomeraniec, Dale Ding, Ching-Jen Chen, Davis G. Taylor, and Kenneth C. Liu
Stenosis of the transverse sinus (TS) and sigmoid sinus (SS), with a trans-stenosis pressure gradient, has been implicated in the pathophysiology of idiopathic intracranial hypertension (IIH). MRI has shown improvement in TS and SS stenosis after high-volume lumbar puncture (HVLP) in a subset of patients with IIH. The authors present the first report of an IIH patient with immediate post-HVLP TS and SS trans-stenosis pressure gradient reduction and an attendant increase in TS and SS cross-sectional area confirmed using intravascular ultrasonography (IVUS). Recurrence of the patient’s TS-SS stenosis coincided with elevated HVLP opening pressure, and venous sinus stent placement resulted in clinical improvement. This report suggests that TS and SS stenosis may be a downstream effect of elevated intracranial pressure in IIH, rather than its principal etiological mechanism. However, the authors hypothesize that endovascular stenting may obliterate a positive feedback loop involving trans-stenosis pressure gradients, and still benefit appropriately selected patients.
Adeel Ilyas, Ching-Jen Chen, Dale Ding, Panagiotis Mastorakos, Davis G. Taylor, I. Jonathan Pomeraniec, Cheng-Chia Lee, and Jason Sheehan
Cyst formation can occasionally occur after stereotactic radiosurgery (SRS) for brain arteriovenous malformations (AVMs). Given the limited data regarding post-SRS cyst formation in patients with AVM, the time course, natural history, and management of this delayed complication are poorly defined. The aim of this systematic review was to determine the incidence, time course, and optimal management of cyst formation after SRS for AVMs.
A literature review was performed using PubMed to identify studies reporting cyst formation in AVM patients treated with SRS. Baseline and outcomes data, including the incidence and management of post-SRS cysts, were extracted from each study that reported follow-up duration. The mean time to cyst formation was calculated from the subset of studies that reported individual patient data.
Based on pooled data from 22 studies comprising the incidence analysis, the overall rate of post-SRS cyst formation was 3.0% (78/2619 patients). Among the 26 post-SRS cyst patients with available AVM obliteration data, nidal obliteration was achieved in 20 (76.9%). Of the 64 cyst patients with available symptomatology and management data, 21 (32.8%) were symptomatic; 21 cysts (32.8%) were treated with surgical intervention, whereas the remaining 43 (67.2%) were managed conservatively. Based on a subset of 19 studies reporting individual time-to-cyst-formation data from 63 patients, the mean latency period to post-SRS cyst formation was 78 months (6.5 years).
Cyst formation is an uncommon complication after SRS for AVMs, with a relatively long latency period. The majority of post-SRS cysts are asymptomatic and can be managed conservatively, although enlarging or symptomatic cysts may require surgical intervention. Long-term follow-up of AVM patients is crucial to the appropriate diagnosis and management of post-SRS cysts.
Adeel Ilyas, Ching-Jen Chen, Dale Ding, Andrew Romeo, Thomas J. Buell, Tony R. Wang, M. Yashar S. Kalani, and Min S. Park
Stroke is one of the leading causes of death worldwide and a significant source of long-term morbidity. Unfortunately, a substantial number of stroke patients either are ineligible or do not significantly benefit from contemporary medical and interventional therapies. To address this void, investigators recently made technological advances to render transcranial MR-guided, high-intensity focused ultrasound (MRg-HIFU) sonolysis a potential therapeutic option for both acute ischemic stroke (AIS)—as an alternative for patients with emergent large-vessel occlusion (ELVO) who are ineligible for endovascular mechanical thrombectomy (EMT) or as salvage therapy for patients in whom EMT fails—and intracerebral hemorrhage (ICH)—as a neoadjuvant means of clot lysis prior to surgical evacuation. Herein, the authors review the technological principles behind MRg-HIFU sonolysis, its results in in vitro and in vivo stroke models, and its potential clinical applications. As a noninvasive transcranial technique that affords rapid clot lysis, MRg-HIFU thrombolysis may develop into a therapeutic option for patients with AIS or ICH. However, additional studies of transcranial MRg-HIFU are necessary to ascertain the merit of this treatment approach for thrombolysis in both AIS and ICH, as well as its technical limitations and risks.
Ching-Jen Chen, Pedro Norat, Dale Ding, George A. C. Mendes, Petr Tvrdik, Min S. Park, and M. Yashar Kalani
Endovascular embolization of brain arteriovenous malformations (AVMs) is conventionally performed from a transarterial approach. Transarterial AVM embolization can be a standalone treatment or, more commonly, used as a neoadjuvant therapy prior to microsurgery or stereotactic radiosurgery. In contrast to the transarterial approach, curative embolization of AVMs may be more readily achieved from a transvenous approach. Transvenous embolization is considered a salvage therapy in contemporary AVM management. Proposed indications for this approach include a small (diameter < 3 cm) and compact AVM nidus, deep AVM location, hemorrhagic presentation, single draining vein, lack of an accessible arterial pedicle, exclusive arterial supply by perforators, and en passage feeding arteries. Available studies of transvenous AVM embolization in the literature have reported high complete obliteration rates, with reasonably low complication rates. However, evaluating the efficacy and safety of this approach is challenging due to the limited number of published cases. In this review the authors describe the technical considerations, indications, and outcomes of transvenous AVM embolization.
Adeel Ilyas, Ching-Jen Chen, Dale Ding, Davis G. Taylor, Shayan Moosa, Cheng-Chia Lee, Or Cohen-Inbar, and Jason P. Sheehan
Several recent studies have improved our understanding of the outcomes of volume-staged (VS) and dose-staged (DS) stereotactic radiosurgery (SRS) for the treatment of large (volume > 10 cm3) brain arteriovenous malformations (AVMs). In light of these recent additions to the literature, the aim of this systematic review is to provide an updated comparison of VS-SRS and DS-SRS for large AVMs.
A systematic review of the literature was performed using PubMed to identify cohorts of 5 or more patients with large AVMs who had been treated with VS-SRS or DS-SRS. Baseline data and post-SRS outcomes were extracted for analysis.
A total of 11 VS-SRS and 10 DS-SRS studies comprising 299 and 219 eligible patients, respectively, were included for analysis. The mean obliteration rates for VS-SRS and DS-SRS were 41.2% (95% CI 31.4%–50.9%) and 32.3% (95% CI 15.9%–48.8%), respectively. Based on pooled individual patient data, the outcomes for patients treated with VS-SRS were obliteration in 40.3% (110/273), symptomatic radiation-induced changes (RICs) in 13.7% (44/322), post-SRS hemorrhage in 19.5% (50/256), and death in 7.4% (24/323); whereas the outcomes for patients treated with DS-SRS were obliteration in 32.7% (72/220), symptomatic RICs in 12.2% (31/254), post-SRS hemorrhage in 10.6% (30/282), and death in 4.6% (13/281).
Volume-staged SRS appears to afford higher obliteration rates than those achieved with DS-SRS, although with a less favorable complication profile. Therefore, VS-SRS or DS-SRS may be a reasonable treatment approach for large AVMs, either as stand-alone therapy or as a component of a multimodality management strategy.