The Preventable Shunt Revision Rate: a potential quality metric for pediatric shunt surgery.

OBJECTIVE Shunt surgery consumes a large amount of pediatric neurosurgical health care resources. Although many studies have sought to identify risk factors for shunt failure, there is no consensus within the literature on variables that are predictive or protective. In this era of "quality outcome measures," some authors have proposed various metrics to assess quality outcomes for shunt surgery. In this paper, the Preventable Shunt Revision Rate (PSRR) is proposed as a novel quality metric. METHODS An institutional shunt database was queried to identify all shunt surgeries performed from January 1, 2010, to December 31, 2014, at Le Bonheur Children's Hospital. Patients' records were reviewed for 90 days following each "index" shunt surgery to identify those patients who required a return to the operating room. Clinical, demographic, and radiological factors were reviewed for each index operation, and each failure was analyzed for potentially preventable causes. RESULTS During the study period, there were 927 de novo or revision shunt operations in 525 patients. A return to the operating room occurred 202 times within 90 days of shunt surgery in 927 index surgeries (21.8%). In 67 cases (33% of failures), the revision surgery was due to potentially preventable causes, defined as inaccurate proximal or distal catheter placement, infection, or inadequately secured or assembled shunt apparatus. Comparing cases in which failure was due to preventable causes and those in which it was due to nonpreventable causes showed that in cases in which failure was due to preventable causes, the patients were significantly younger (median 3.1 vs 6.7 years, p = 0.01) and the failure was more likely to occur within 30 days of the index surgery (80.6% vs 64.4% of cases, p = 0.02). The most common causes of preventable shunt failure were inaccurate proximal catheter placement (33 [49.3%] of 67 cases) and infection (28 [41.8%] of 67 cases). No variables were found to be predictive of preventable shunt failure with multivariate logistic regression. CONCLUSIONS With economic and governmental pressures to identify and implement "quality measures" for shunt surgery, pediatric neurosurgeons and hospital administrators must be careful to avoid linking all shunt revisions with "poor" or less-than-optimal quality care. To date, many of the purported risk factors for shunt failure and causes of shunt revision surgery are beyond the influence and control of the surgeon. We propose the PSRR as a specific, meaningful, measurable, and-hopefully-modifiable quality metric for shunt surgery in children.

Predicting shunt failure in children: should the global shunt revision rate be a quality measure?

OBJECT: Ventricular shunts for pediatric hydrocephalus continue to be plagued with high failure rates. Reported risk factors for shunt failure are inconsistent and controversial. The raw or global shunt revision rate has been the foundation of several proposed quality metrics. The authors undertook this study to determine risk factors for shunt revision within their own patient population. METHODS: In this single-center retrospective cohort study, a database was created of all ventricular shunt operations performed at the authors' institution from January 1, 2010, through December 2013. For each index shunt surgery, demographic, clinical, and procedural variables were assembled. An "index surgery" was defined as implantation of a new shunt or the revision or augmentation of an existing shunt system. Bivariate analyses were first performed to evaluate individual effects of each independent variable on shunt failure at 90 days and at 180 days. A final multivariate model was chosen for each outcome by using a backward model selection approach. RESULTS: There were 466 patients in the study accounting for 739 unique ("index") operations, for an average of 1.59 procedures per patient. The median age for the cohort at the time of the first shunt surgery was 5 years (range 0-35.7 years), with 53.9% males. The 90- and 180-day shunt failure rates were 24.1% and 29.9%, respectively. The authors found no variable-demographic, clinical, or procedural-that predicted shunt failure within 90 or 180 days. CONCLUSIONS: In this study, none of the risk factors that were examined were statistically significant in determining shunt failure within 90 or 180 days. Given the negative findings and the fact that all other risk factors for shunt failure that have been proposed in the literature thus far are beyond the control of the surgeon (i.e., nonmodifiable), the use of an institution's or individual's global shunt revision rate remains questionable and needs further evaluation before being accepted as a quality metric.

Surgical Outcomes for Minimally Invasive vs Open Transforaminal Lumbar Interbody Fusion: An Updated Systematic Review and Meta-analysis.

BACKGROUND: Minimally invasive transforaminal lumbar interbody fusion (TLIF)-or MI-TLIF-has been increasing in prevalence compared with open TLIF (O-TLIF) procedures. The use of MI-TLIF is an evolving technique with conflicting reports in the literature about outcomes. OBJECTIVE: To investigate the impact of MI-TLIF in comparison with O-TLIF for early and late outcomes by using the Visual Analog Scale for back pain (VAS-back) and the Oswestry Disability Index (ODI). Secondary end points include blood loss, operative time, radiation exposure, length of stay, fusion rates, and complications between the 2 procedures. METHODS: During August 2014, a systematic literature search was performed identifying 987 articles. Of these, 30 met inclusion criteria. A random-effects meta-analysis was performed by using both pooled and subset analyses based on study type. RESULTS: Our meta-analysis demonstrated that MI-TLIF reduced blood loss (P < .001), length of stay (P < .001), and complications (P = .001) but increased radiation exposure (P < .001). No differences were found in fusion rate (P = .61) and operative time (P = .34). A decrease in late VAS-back scores was demonstrated for MI TLIF (P < .001), but no differences were found in early VAS-back, early ODI, and late ODI. CONCLUSION: MI-TLIF is associated with reduced blood loss, decreased length of stay, decreased complication rates, and increased radiation exposure. The rates of fusion and operative time are similar between MI-TLIF and O-TLIF. Differences in long-term outcomes in MI-TLIF vs O-TLIF are inconclusive and require more research, particularly in the form of large, multi-institutional prospective randomized controlled trials. ABBREVIATIONS: CI, confidence intervalMCID, minimal clinically important differenceMI-TLIF, minimally invasive transforaminal lumbar interbody fusionODI, Oswestry Disability IndexO-TLIF, open transforaminal lumbar interbody fusionVAS, Visual Analog Scale.

Regulation of reactive oxygen species by p53: implications for nitric oxide-mediated apoptosis.

Nitric oxide (NO) induces vascular smooth muscle cell (VSMC) apoptosis in part through activation of p53. Traditionally, p53 has been thought of as the gatekeeper, determining if a cell should undergo arrest and repair or apoptosis following exposure to DNA-damaging agents, depending on the severity of the damage. However, our laboratory previously demonstrated that NO induces apoptosis to a much greater extent in p53(-/-) compared with p53(+/+) VSMC. Increased reactive oxygen species (ROS) within VSMC has been shown to induce VSMC apoptosis, and recently it was found that the absence of, or lack of, functional p53 leads to increased ROS and oxidative stress within different cell types. This study investigated the differences in intracellular ROS levels between p53(-/-) and p53(+/+) VSMC and examined if these differences were responsible for the increased susceptibility to NO-induced apoptosis observed in p53(-/-) VSMC. We found that p53 actually protects VSMC from NO-induced apoptosis by increasing antioxidant protein expression [i.e., peroxiredoxin-3 (PRx-3)], thereby reducing ROS levels and cellular oxidative stress. We also observed that the NO-induced apoptosis in p53(-/-) VSMC was largely abrogated by pretreatment with catalase. Furthermore, when the antioxidant protein PRx-3 and its specific electron acceptor thioredoxin-2 were silenced within p53(+/+) VSMC with small-interfering RNA, not only did these cells exhibit greater ROS production, but they also exhibited increased NO-induced apoptosis similar to that observed in p53(-/-) VSMC. These findings suggest that ROS mediate NO-induced VSMC apoptosis and that p53 protects VSMC from NO-induced apoptosis by decreasing intracellular ROS. This research demonstrates that p53 has antioxidant functions in stressed cells and also suggests that p53 has antiapoptotic properties.