clinical style. Usually, this phase is characterized by progressively increasing surgical volume, which in turn generates more volume and practice opportunities. Also at this time, it is difficult to establish work/life balance, as personal and family issues often peak as the neurosurgeon enters his or her late 30s. The importance of self-discovery as a surgeon is characterized by distinguishing ourselves from those around us and determining what is important to us. The neurosurgeon must experiment and learn by trial and error. Some of the things that we try do not go
Ralph G. Dacey Jr.
Ralph G. Dacey Jr.
of nearly 6000 pediatric patients in approximately 250 hospitals, treated by approximately 400 neurosurgeons. In this group, 0.5% of the patients died, 1% were transferred to another acute-care facility, and 1.7% were transferred to long-term care or rehabilitation facilities. The mortality rates associated with placement of a shunt were 0.7% for the primary procedure, and 0.4 and 0.2% for proximal and distal revisions, respectively. Their most striking finding is that the mortality rate for patients treated at high-volume hospitals and by high-volume surgeons
Roberto C. Heros
This is an excellent retrospective study of the relationship between hospital case volume and mortality rates in patients admitted through the emergency department of an acute-care hospital with the diagnosis of subarachnoid hemorrhage (SAH). The data are derived from records kept in 18 states representing 58% of the US population. Although my expertise with statistics in general and with this type of epidemiological research in particular is limited, the paper has been duly reviewed by an individual with such expertise who found no major flaws with the
DeWitte T. Cross III, David L. Tirschwell, Mary Ann Clark, Dan Tuden, Colin P. Derdeyn, Christopher J. Moran and Ralph G. Dacey Jr.
C ase volume is related to outcome in a variety of procedures. For carotid endarterectomy, craniotomy for aneurysm clip placement, coronary artery bypass grafting, coronary angioplasty, pancreatic resection, joint replacement surgery, esophagectomy, pneumonectomy, and other surgical procedures, higher case volumes are correlated with lower mortality rates. 1, 3–6, 8, 11, 16–19, 24–26, 30 When a case volume—mortality rate relationship is identified, it may be possible to use that relationship to improve outcomes. Policies implemented in Canada and New York to
Masakazu Takayasu and Ralph G. Dacey Jr.
H yperemic phenomena play important roles in the pathophysiology of the cerebral circulation, since intracranial blood volume can fluctuate only between certain finite limits. Phenomena that appear to involve cerebral hyperemia include post-reperfusion hyperemia, 10, 14 the rapid increase in intracranial pressure (ICP) after subarachnoid hemorrhage (SAH), 8, 18 normal perfusion pressure breakthrough encountered during the surgical treatment of arteriovenous malformations (AVM's), 24 and ICP plateau waves. 13, 22 Neurogenic, metabolic, and myogenic
S. Kathleen Bandt and Ralph G. Dacey Jr.
—critical review of the “h” index and its variants . World Neurosurg 80 : e85 – e90 , 2013 2 Barendse W : The strike rate index: a new index for journal quality based on journal size and the h-index of citations . Biomed Digit Libr 4 : 3 , 2007 10.1186/1742-5581-4-3 17445275 3 Bjork B , Roos A , Lauri M : Scientific journal publishing: yearly volume and open access availability . Inform Res 14 : 391 , 2009 4 Bornmann L : Are there better indices for evaluation purposes than the h index? . J Am Soc Inf Sci 59 : 830 – 837 , 2008 10.1002/asi.20806 5
Hans H. Dietrich and Ralph G. Dacey Jr.
cells. However, the cell volume of penetrating arterioles consists mostly of smooth-muscle cells, and most likely the measurements were obtained from these cells. In addition, the use of high magnification enabled us to clearly identify smooth-muscle cells. We used special care not to penetrate the vessel wall with the microelectrode, so it is unlikely that we obtained measurements from endothelial cells. Our intracellular staining indicated that circumferentially oriented cells were impaled, suggesting that smooth-muscle cells rather than endothelial cells were the
Matthew A. Howard III, Ralph G. Dacey Jr. and H. Richard Winn
test tube was filled to a final calculated volume of 10 µ l/block. The tissue was disrupted into a fine cell suspension by gentle pipetting with a sterile fire-polished Pasteur pipette. The suspension was then drawn into a Hamilton syringe and transplanted stereotaxically into a pair of recipient rats. A 10- µ l sample of the suspension was drawn up for each pair of transplant recipients. One of each pair of rats received the first 5- µ l aliquot and the other received the second 5- µ l aliquot from the same syringe. In this way both rats in each pair were injected
Matthew A. Howard III, Alan S. Gross, Ralph G. Dacey Jr. and H. Richard Winn
treatment. “Functional survival” is defined as a GOS grade of good or moderately disabled. TABLE 2 Time from head injury to emergency room admission Time Interval Older Group Younger Group < 1 hr 15 11 1 to < 3 hrs 3 8 3 to 6 hrs 2 1 > 6 hrs 8 6 unknown 6 7 total cases 34 33 Fifty-two admission CT scans (22 in the young group and 30 in the old group) were available for analysis of acute SDH volume, size of midline shift, and presence or absence of intracerebral
Roberto C. Heros
literature. Essentially, the authors planned their embolization, which is frequently done in several sessions, to reduce the overall volume of the AVM by attacking peripheral compartments rather than using a shotgun approach of embolization to simply reduce the flow to the malformation. In this manner, the authors achieved a very significant reduction in volume of the AVMs, thus making them amenable to radiosurgical treatment. Using this treatment paradigm, they achieved better results in terms of postprocedural hemorrhage (none in the patients included in their series