Faculty Bibliography

Acute kidney injury (AKI) is common in hospitalized patients of all ages and is associated with significant morbidity and mortality. Accurate prediction and early identification of AKI is of utmost importance because no therapy exists to mitigate AKI once it has occurred. Yet, serum creatinine lacks adequate sensitivity and specificity, and quantification of urine output is challenging in incontinent children without indwelling bladder catheters. Integration of clinically available biomarkers have the potential to delineate unique AKI phenotypes that could have important prognostic and therapeutic implications. Plasma Cystatin C, urine neutrophil gelatinase associated lipocalin (NGAL) and the urinary product of tissue inhibitor metalloproteinase (TIMP-2) and insulin growth factor binding protein-7 (IGFBP7) are clinically available. These biomarkers have been studied in heterogenous populations across the age spectrum and in a variety of clinical settings for prediction of AKI. The purpose of this review is to describe and discuss the clinically available AKI biomarkers including how they have been used to delineate AKI phenotypes.

Acute kidney injury (AKI) is common in critically ill children and adults, and sepsis-associated AKI (SA-AKI) is the most frequent cause of AKI in the ICU. To date, no mechanistically targeted therapeutic interventions have been identified. High-throughput "omic" technologies (e.g., genomics, proteomics, metabolomics, etc.) offer a new angle of approach to achieve this end. In this review, we provide an update on the current understanding of SA-AKI pathophysiology. Omic technologies themselves are briefly discussed to facilitate interpretation of studies using them. We next summarize the body of SA-AKI research to date that has employed omic technologies. Importantly, omic studies are helping to elucidate a pathophysiology of SA-AKI centered around cellular stress responses, metabolic changes, and dysregulation of energy production that underlie its clinical features. Finally, we propose opportunities for future research using clinically relevant animal models, integrating multiple omic technologies and ultimately progressing to translational human studies focusing therapeutic strategies on targeted disease mechanisms.

The evolution of neurosurgery has been, and continues to be, closely associated with innovations in technology. Modern neurosurgery is wed to imaging technology and the future promises even more dependence on anatomic and, perhaps more importantly, functional imaging. The photoacoustic phenomenon was described nearly 140 yr ago; however, biomedical applications for this technology have only recently received significant attention. Light-based photoacoustic and microwave-based thermoacoustic technologies represent novel biomedical imaging modalities with broad application potential within and beyond neurosurgery. These technologies offer excellent imaging resolution while generally considered safer, more portable, versatile, and convenient than current imaging technologies. In this review, we summarize the current state of knowledge regarding photoacoustic and thermoacoustic imaging and their potential impact on the field of neurosurgery.

We describe a series of 14 surgical blister aneurysm (BA) patients and compare outcomes in those with known cerebral BA to those lacking preoperative BA diagnosis/recognition. BA are broad, fragile, pathologic dilatations of the intracranial arteries. They have a low prevalence but are associated with substantially higher surgical morbidity and mortality rates than saccular aneurysms. A confirmed, preoperative BA diagnosis can alter operative management and technique. We performed a retrospective review of prospectively collected data on aneurysm patients undergoing surgery at a major academic institution. All patients from 1990 to 2011 with a postoperative BA diagnosis were included. Chart reviews were performed to identify patients with preoperative BA diagnoses and collect descriptive data. We identified 14 patients, 12 of whom presented with subarachnoid hemorrhage. The age of the cohort (mean ± standard deviation: 41.8 ± 13.9 years) was lower than that generally reported for saccular aneurysm populations. Preoperatively diagnosed BA had an intraoperative rupture (IOR) rate of 28.6% (2/7) compared to a 57.1% (4/7) rate in the undiagnosed patients. The mortality rate in the preoperatively diagnosed cohort was 14.3% (1/7) while that of the undiagnosed group was 42.8% (3/7). BA remain a diagnostic and treatment challenge with morbidity and mortality rates exceeding those of saccular aneurysms. Preoperative BA diagnosis may decrease IOR and mortality rates and improve patient outcomes.