Visish M. Srinivasan and Peter Kan
Visish M. Srinivasan, Peter Kan and Edward A. M. Duckworth
Visish M. Srinivasan, Gouthami Chintalapani, Edward A. M. Duckworth and Peter Kan
The evaluation of the venous neurovasculature, especially the dural venous sinuses, is most often performed using MR or CT venography. For further assessment, diagnostic cerebral angiography may be performed. Three-dimensional rotational angiography (3D-RA) can be applied to the venous system, producing 3D rotational venography (3D-RV) and cross-sectional reconstructions, which function as an adjunct to traditional 2D digital subtraction angiography.
After querying the database of Baylor St. Luke’s Medical Center in Houston, Texas, the authors reviewed the radiological and clinical data of patients who underwent 3D-RV. This modality was performed based on standard techniques for 3D-RA, with the catheter placed in the internal carotid artery and a longer x-ray delay calculated based on time difference between the early arterial phase and the venous phase.
Of the 12 cases reviewed, 5 patients had neoplasms invading a venous sinus, 4 patients with idiopathic intracranial hypertension required evaluation of venous sinus stenosis, 2 patients had venous diverticula, and 1 patient had a posterior fossa arachnoid cyst. The x-ray delay ranged from 7 to 10 seconds. The 3D-RV was used both for diagnosis and in treatment planning.
Three-dimensional RV and associated cross-sectional reconstructions can be used to assess the cerebral venous vasculature in a manner distinct from established modalities. Three-dimensional RV can be performed with relative ease on widely available biplane equipment, and data can be processed using standard software packages. The authors present the protocol and technique used along with potential applications to venous sinus stenosis, venous diverticula, and tumors invading the venous sinuses.
Visish M. Srinivasan, Brent R. O'Neill, Diana Jho, Donald M. Whiting and Michael Y. Oh
External ventricular drainage (EVD) is one of the most commonly performed neurosurgical procedures. It was first performed as early as 1744 by Claude-Nicholas Le Cat. Since then, there have been numerous changes in technique, materials used, indications for the procedure, and safety. The history of EVD is best appreciated in 4 eras of progress: development of the technique (1850–1908), technological advancements (1927–1950), expansion of indications (1960–1995), and accuracy, training, and infection control (1995–present). While EVD was first attempted in the 18th century, it was not until 1890 that the first thorough report of EVD technique and outcomes was published by William Williams Keen. He was followed by H. Tillmanns, who described the technique that would be used for many years. Following this, many improvements were made to the EVD apparatus itself, including the addition of manometry by Adson and Lillie in 1927, and continued experimentation in cannulation/drainage materials. Technological advancements allowed a great expansion of indications for EVD, sparked by Nils Lundberg, who published a thorough analysis of the use of intracranial pressure (ICP) monitoring in patients with brain tumors in 1960. This led to the application of EVD and ICP monitoring in subarachnoid hemorrhage, Reye syndrome, and traumatic brain injury. Recent research in EVD has focused on improving the overall safety of the procedure, which has included the development of guidance-based systems, virtual reality simulators for trainees, and antibiotic-impregnated catheters.
Visish M. Srinivasan, Stephen R. Chen, Kevin M. Camstra, Gouthami Chintalapani and Peter Kan
Stroke is a major cause of disability and death in adults. Several large randomized clinical trials have shown the significant benefit of mechanical thrombectomy with modern stent retrievers in the treatment of large-vessel occlusions. However, large clots located at bifurcations remain challenging to treat. An in vivo model of these recalcitrant clots needs to be developed to test future generations of devices.
Autologous blood was drawn from anesthetized swine via a femoral sheath. Blood was then mixed with thrombin, calcium chloride, and saline, and injected into silicone tubing to form cylindrical clots in the standard fashion. Matured clots were then delivered in an unfragmented fashion directly into the distal extracranial vasculature, at branch points where vessel sizes mimic the human middle cerebral artery, by using Penumbra aspiration tubing and the Penumbra ACE68 reperfusion catheter.
A total of 5 adult swine were used to develop the model. The techniques evolved during experiments in the first 3 animals, and the last 2 were used to establish the final model. In these 2 swine, a total of 8 autologous clots, 15–20 mm, were injected directly into 8 distal extracranial vessels at branch points to mimic a bifurcation occlusion in a human. All clots were delivered directly at a distal bifurcation or trifurcation in an unfragmented fashion to cause an occlusion. Ten revascularization attempts were made, and none of the branch-point occlusions were fully revascularized on the first attempt.
Using novel large-bore distal access catheters, large unfragmented clots can be delivered into distal extracranial vessels in a swine occlusion model. The model mimics the clinical situation of a recalcitrant bifurcation occlusion and will be valuable in the study of next-generation stroke devices and in training settings.
Visish M. Srinivasan, Peter Kan and Edward A. M. Duckworth
Visish M. Srinivasan, Aditya Vedantam and Peter Kan
We present a case of a patient with an anterior communicating artery aneurysm treated by PulseRider-assisted coil embolization. PulseRider is a new device, FDA approved for treatment of broad-necked aneurysms of the basilar apex or internal carotid artery terminus. The aneurysm was broad-necked and involved the anterior communicating artery and was considered for traditional stent-assisted coiling as well as PulseRider-assisted coiling. The authors present the treatment plan and strategy and then fluoroscopic recording of the PulseRider delivery and subsequent coiling phase. Nuances of technique for this new device used in a challenging setting are discussed.
The video can be found here: https://youtu.be/ont7ggqgLH8.
Visish M. Srinivasan, Patrick J. Karas, Anish N. Sen and Jared S. Fridley
Sandi K. Lam, Visish M. Srinivasan, Thomas G. Luerssen and I-Wen Pan
There have been no large-scale analyses on cost drivers in CSF shunt surgery for the treatment of pediatric hydrocephalus. The objective of this study was to develop a cost model for hospitalization costs in pediatric CSF shunt surgery and to examine risk factors for increased costs.
Data were extracted from the Kids' Inpatient Database (KID) of the Healthcare Cost and Utilization Project. Children with initial CSF shunt placement in the 2009 KID were examined. Patient charge was converted to cost using a cost-to-charge ratio. The factors associated with costs of CSF shunt hospitalizations were examined, including patient demographics, hospital characteristics, and clinical data. The natural log transformation of cost per inpatient day (CoPID) was analyzed. Three multivariate linear regression models were used to characterize the cost. Variance inflation factor was used to identify multicollinearity for each model.
A total of 2519 patients met the inclusion criteria and were included in study. Average cost and length of stay (LOS) for initial shunt placement were $49,317 ± $74,483 (US) and 18.2 ± 28.5 days, respectively. Cost per inpatient day was $4249 ± $2837 (median $3397, range $80–$22,263). The average number of registered nurse (RN) full-time equivalents (FTEs) per 1000 adjusted inpatient days was 5.8 (range 1.6–10.8). The final model had the highest adjusted coefficient of determination (R2 = 0.32) and was determined to be the best among 3 models. The final model showed that child age, hydrocephalus etiology, weekend admission, number of chronic diseases, hospital type, number of RN FTEs per 1000 adjusted inpatient days, number of procedures, race, insurance type, income level, and hospital regions were associated with CoPID.
A patient's socioeconomic status, such as race, income level, and insurance, in addition to hospitalrelated factors such as number of hospital RN FTEs, hospital type, and US region, could affect the costs of initial CSF shunt placement, in addition to clinical factors such as hydrocephalus origin and LOS. To create a cost model of initial CSF shunt placement in the pediatric population, consideration of such nonclinical factors may be warranted.
Michael G. Z. Ghali, Visish M. Srinivasan, Andrew Jea and Sandi Lam
Paul Louis Tessier is recognized as the father of craniofacial surgery. While his story and pivotal contributions to the development of the multidisciplinary practice of craniofacial surgery are much highlighted in plastic surgery literature, they are seldom directly discussed in the context of neurosurgeons. His life and legacy to craniosynostosis and neurosurgery are explored in the present paper.