Dr. George W. Smith is credited with developing the Smith-Robinson procedure, the automatic drill, the vessel-encircling aneurysm clip, and treatment of tic douloureux with stilbamidine. His contributions to neurosurgery were unfortunately truncated by his untimely death. This article highlights his career and his contributions.
Angela Viers, Marshall B. Allen Jr. and Cargill H. Alleyne Jr.
Report of two cases
Cargill H. Alleyne Jr. and Daniel L. Barrow
✓ The use of cadaveric human dura has been critical in the repair of dural defects since the dawn of neurosurgery. Reports in the literature of immune response to this type of graft have been extremely rare. Two patients are presented who received cadaveric dural implants with resulting meningeal signs and cerebrospinal fluid eosinophilia several weeks after surgery. Peripheral eosinophilia was present in one patient. The signs and symptoms resolved temporarily during corticosteroid therapy and permanently upon removal of the offending grafts. These cases illustrate that an immune-type reaction can occur with significant morbidity in patients receiving cadaveric dural grafts. A proposed mechanism for this response is discussed.
Khoi D. Nguyen, Ehizele Osehobo and Cargill H. Alleyne Jr.
Scott Y. Rahimi, John H. Brown, Samuel D. Macomson, Michael A. Jensen and Cargill H. Alleyne Jr.
✓ Cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is a disease process for which the lack of effective treatments has plagued neurosurgeons for decades. Historically, successful treatment after SAH in the acute setting was often followed by a rapid, uncontrollable deterioration in the subacute interval. Little was known regarding the nature and progression of this condition until the mid-1800s, when the disease was first described by Gull. Insight into the origin and natural history of cerebral vasospasm came slowly over the next 100 years, until the 1950s. Over the past five decades our understanding of cerebral vasospasm has expanded exponentially. This newly discovered information has been used by neurosurgeons worldwide for successful treatment of complications associated with vasospasm. Nevertheless, although great strides have been made toward elucidating the causes of cerebral vasospasm, a lasting cure continues to elude experts and the disease continues to wreak havoc on patients after aneurysmal SAH.
Cargill H. Alleyne Jr., C. Michael Cawley, George G. Shengelaia and Daniel L. Barrow
Object. The blood supply of the lower spinal cord is heavily dependent on the artery of Adamkiewicz, which characteristically originates from one of the thoracolumbar segmental arteries. The aforementioned artery is of enormous clinical, surgical, and radiological importance, and the goal of this study was to elucidate the course and branches of the segmental artery that gives rise to this important vessel.
Methods. In this cadaveric, microsurgical anatomical study, the authors investigate and describe the course and branches of the artery of Adamkiewicz and the segmental branch from which it ultimately originates. A review of the literature is provided.
Conclusions. By documenting the microsurgical anatomy of these important vessels, this study facilitates an understanding of the anatomy that will aid in treatment planning for surgery of various lesions in this area.
Scott Y. Rahimi, Cargill H. Alleyne Jr., Eric Vernier, Mark R. Witcher and John R. Vender
Patients undergoing craniotomies have traditionally received opiates with acetaminophen for the management of their postoperative pain. The use of narcotic pain medications can be costly, decrease rates of early postoperative ambulation, lengthen hospital stays, and alter a patient's neurological examination. The use of alternative pain medications such as tramadol may benefit patients by resolving many of these issues.
The authors conducted a randomized, blinded prospective study to evaluate the efficacy of alternative pain management strategies for patients following craniotomies. Fifty patients were randomly assigned either to a control group who received narcotics and acetaminophen alone or an experimental group who received tramadol in addition to narcotic pain medications (25 patients assigned to each group).
The control group was noted to have statistically significant higher visual analog scale pain scores, an increased length of hospital stay, and increased narcotic use compared with the tramadol group. The narcotics and acetaminophen group also had increased hospitalization costs when compared with the tramadol group.
The use of scheduled atypical analgesics such as tramadol in addition to narcotics with acetaminophen for the management of postoperative pain after craniotomy may provide better pain control, decrease the side effects associated with narcotic pain medications, encourage earlier postoperative ambulation, and reduce total hospitalization costs.
Cargill H. Alleyne Jr., C. Michael Cawley, George G. Shengelaia and Daniel L. Barrow
The blood supply of the lower spinal cord is heavily dependent on the artery of Adamkiewicz, which characteristically originates from one of the thoracolumbar segmental arteries. The aforementioned artery is of enormous clinical, surgical, and radiological importance, and the goal of this study was to elucidate the course and branches of the segmental artery that gives rise to this important vessel.
In this cadaveric, microsurgical anatomical study, the authors investigate and describe the course and branches of the artery of Adamkiewicz and the segmental branch from which it ultimately originates. A review of the literature is provided.
By documenting the microsurgical anatomy of these important vessels, this study facilitates an understanding of the anatomy that will aid in treatment planning for surgery of various lesions in this area.
Nathan Todnem, Khoi D. Nguyen, Vamsi Reddy, Dayton Grogan, Taylor Waitt and Cargill H. Alleyne Jr.
External ventricular drain (EVD) placement is one of first cranial procedures neurosurgery residents are expected to perform independently. While proper training improves patient outcomes, there are few options for practicing EVD placement prior to placing the EVD in patients in a clinical setting. Proposed solutions to this include using cadaveric models and virtual simulations, but barriers exist with these as well in regard to authenticity. EVD simulators using virtual reality technologies are a promising new technique for training, but the cost of these devices poses a barrier to general/widespread accessibility among smaller programs or underserved hospitals. The authors desribe a novel, yet simple, and cost-effective technique (less than $5 per mold) for developing a brain model constructed of homemade ballistics gelatin that can be used for teaching and practicing the placement of EVD.
A brain model is made with ballistics gelatin using an anatomically correct skull model as a mold. A 3D-printed ventricular system model is used to create a mold of an anatomically correct ventricular system in the brain model. A group of medical students (n = 10) were given a basic presentation about EVD placement, including standard landmarks and placement techniques, and were also shown a demonstration of EVD placement on the brain model. They were then allowed to perform an EVD placement using the brain model. The students were surveyed on their experience with using the brain model, including usability and practicality of the model. Accuracy of EVD placement by each student was also assessed, with adequate position of catheter tip being in the ipsilateral frontal horn.
The final product is fairly inexpensive and easy to make. It is soft enough to pass a catheter through, but it is also firm enough to maintain its shape, including a cavity representing the lateral ventricles. The dense gelatin holds the catheter in its final resting position, while the two halves are separated and inspected. All participants in the test group of medical students reported that the brain model was easy to use, helped them understand the steps and technique of EVD placement, and provided good feedback on the ideal position of ventricular catheters. All of the participants in the group had adequate positioning of their ventricular catheters after one attempt.
The presented brain model is easy to replicate, inexpensive, anatomically accurate, and provides a medium for neurosurgeons to teach and practice ventricular catheter placement in a risk-free environment.
Cargill H. Alleyne Jr., C. Michael Cawley, Daniel L. Barrow, Bradley C. Poff, Michelle D. Powell, Amarpreet S. Sawhney and Dirck L. Dillehay
Object. A canine craniotomy model was used to evaluate the dural sealing efficacy and biocompatibility of a novel, synthetic, bioresorbable hydrogel.
Methods. Bilateral craniotomies were performed in 24 dogs assigned to six survival periods. In each animal a parasagittal durotomy was created and then repaired. At the treatment sites the hydrogel sealant was applied over the dural repair and photopolymerized. The repair was tested for leaks to 20 cm H2O by using a Valsalva maneuver. At the control sites the incisions were sutured and tested for leaks only. After uneventful survival periods, the leak test was repeated in three of the four animals in each group. Bone—dura adhesion was evaluated, after which the dura and underlying brain were removed, fixed, and examined histologically. En bloc histological investigation was performed on a specimen obtained from the fourth animal in each group.
Over a 56-day period, 18 treated sites were tested for leaks. A leak was detected at a site remote from that of the repair in one animal; this was excluded from analysis. Thus 17 of 17 treated sites remained free of leaks. On the control side of one animal, there was a leak from a new dural tear at the cranial end of the durotomy, which occurred when the bone flap was removed. This site was also excluded from analysis. Eleven of 17 leak-tested control sites remained free of leaks over the study period. Bone—dura adhesions occurred in 15 of 19 control sites and had a mean adhesion score of 1.37 (range 0–4), whereas adhesions occurred in 10 of 19 treated sites with a mean adhesion score of 0.84 (range 0–3). No cortical reaction was noted.
Conclusions. This novel hydrogel sealant is efficacious in sealing dural repair sites measuring up to 2 mm. Healing of the underlying dura is not compromised and exposed cortical tissue is not altered histologically.
Melanie D. King, D. Jay McCracken, F. Marlene Wade, Steffen E. Meiler, Cargill H. Alleyne Jr. and Krishnan M. Dhandapani
Intracerebral hemorrhage (ICH) is associated with significant morbidity and mortality. Acute hematoma enlargement is an important predictor of neurological injury and poor clinical prognosis; but neurosurgical clot evacuation may not be feasible in all patients and treatment options remain largely supportive. Thus, novel therapeutic approaches to promote hematoma resolution are needed. In the present study, the authors investigated whether the curry spice curcumin limited neurovascular injury following ICH in mice.
Intracerebral hemorrhage was induced in adult male CD-1 mice by intracerebral administration of collagenase or autologous blood. Clinically relevant doses of curcumin (75–300 mg/kg) were administered up to 6 hours after ICH, and hematoma volume, inflammatory gene expression, blood-brain barrier permeability, and brain edema were assessed over the first 72 hours. Neurological assessments were performed to correlate neurovascular protection with functional outcomes.
Curcumin increased hematoma resolution at 72 hours post-ICH. This effect was associated with a significant reduction in the expression of the proinflammatory mediators, tumor necrosis factor–α, interleukin-6, and interleukin-1β. Curcumin also reduced disruption of the blood-brain barrier and attenuated the formation of vasogenic edema following ICH. Consistent with the reduction in neuroinflammation and neurovascular injury, curcumin significantly improved neurological outcome scores after ICH.
Curcumin promoted hematoma resolution and limited neurological injury following ICH. These data may indicate clinical utility for curcumin as an adjunct therapy to reduce brain injury and improve patient outcome.