Recording of elapsed time and temporal information about biological events using Cas9.

DNA has not been utilized to record temporal information, although DNA has been used to record biological information and to compute mathematical problems. Here, we found that indel generation by Cas9 and guide RNA can occur at steady rates, in contrast to typical dynamic biological reactions, and the accumulated indel frequency can be a function of time. By measuring indel frequencies, we developed a method for recording and measuring absolute time periods over hours to weeks in mammalian cells. These time-recordings were conducted in several cell types, with different promoters and delivery vectors for Cas9, and in both cultured cells and cells of living mice. As applications, we recorded the duration of chemical exposure and the lengths of elapsed time since the onset of biological events (e.g., heat exposure and inflammation). We propose that our systems could serve as synthetic "DNA clocks."

Neurovascular Coupling under Chronic Stress Is Modified by Altered GABAergic Interneuron Activity.

Neurovascular coupling (NVC), the interaction between neural activity and vascular response, ensures normal brain function by maintaining brain homeostasis. We previously reported altered cerebrovascular responses during functional hyperemia in chronically stressed animals. However, the underlying neuronal-level changes associated with those hemodynamic changes remained unclear. Here, using in vivo and ex vivo experiments, we investigate the neuronal origins of altered NVC dynamics under chronic stress conditions in adult male mice. Stimulus-evoked hemodynamic and neural responses, especially beta and gamma-band local field potential activity, were significantly lower in chronically stressed animals, and the NVC relationship, itself, had changed. Further, using acute brain slices, we discovered that the underlying cause of this change was dysfunction of neuronal nitric oxide synthase (nNOS)-mediated vascular responses. Using FISH to check the mRNA expression of several GABAergic subtypes, we confirmed that only nNOS mRNA was significantly decreased in chronically stressed mice. Ultimately, chronic stress impairs NVC by diminishing nNOS-mediated vasodilation responses to local neural activity. Overall, these findings provide useful information in understanding NVC dynamics in the healthy brain. More importantly, this study reveals that impaired nNOS-mediated NVC function may be a contributory factor in the progression of stress-related diseases.SIGNIFICANCE STATEMENT The correlation between neuronal activity and cerebral vascular dynamics is defined as neurovascular coupling (NVC), which plays an important role for meeting the metabolic demands of the brain. However, the impact of chronic stress, which is a contributory factor of many cerebrovascular diseases, on NVC is poorly understood. We therefore investigated the effects of chronic stress on impaired neurovascular response to sensory stimulation and their underlying mechanisms. Multimodal approaches, from in vivo hemodynamic imaging and electrophysiology to ex vivo vascular imaging with pharmacological treatment, patch-clamp recording, FISH, and immunohistochemistry revealed that chronic stress-induced dysfunction of nNOS-expressing interneurons contributes to NVC impairment. These findings will provide useful information to understand the role of nNOS interneurons in NVC in normal and pathological conditions.

An impedance-based formulation of frequency-domain nonlinearity indicators in finite-amplitude sound propagation.

Since the Morfey-Howell Q/S was introduced as a single-point frequency-domain nonlinearity indicator for propagation of intense broadband noise [AIAA J. 19, 986-992 (1981)], there has been debate about its validity, utility, and interpretation. In this Letter, the generalized Burgers equation is recast in terms of specific acoustic impedance along with linear absorption and dispersion coefficients, normalized quadspectral density (Q/S), and newly proposed normalized cospectral density (C/S). The formulation leads to a rather straightforward interpretation in which Q/S and C/S, respectively, represent the additional absorption and dispersion at a locale, produced by the passage of a finite-amplitude wave.

Comparison of supramesenteric aortic cross-clamping with supraceliac aortic cross-clamping for aortic reconstruction.

OBJECTIVE: Supraceliac aortic cross-clamping (SCXC) is routinely used during open aortic reconstruction (OAR) of pararenal aortic disease when suprarenal control is not feasible. On occasion, however, aortic control may be obtained at the supramesenteric level by supramesenteric cross-clamping (SMXC) between the superior mesenteric artery and the celiac axis. The purpose of this study was to compare outcomes between patients who had SMXC vs SCXC during OAR for both aneurysmal and occlusive diseases. METHODS: A retrospective chart review identified 69 patients who underwent elective OAR requiring SMXC (n = 18) or SCXC (n = 51). All patients with thoracoabdominal aneurysms and those who had inframesenteric (suprarenal and infrarenal) aortic control were excluded. Propensity score-based matching was performed to adjust for confounding factors in a 1:1 ratio to compare outcomes. Late survival was estimated by Kaplan-Meier methods. RESULTS: Propensity score-based matching was performed at a 1:1 ratio; 18 SMXC cases were matched with 18 SCXC cases. The average age was 66.7 years, and men constituted 72%. Baseline characteristics were matched, except for the incidence of peripheral vascular occlusive disease (72.2% in the SMXC group vs 33.3% in the SCXC group; P = .04). A majority (80.6%) of patients underwent OAR for aneurysmal disease (72.2% in the SMXC group, 88.9% in the SCXC group). Intraoperatively, there were no differences in operative times (325 minutes for SMXC vs 298 minutes for SCXC; P = .48), but the SMXC group had a longer renal ischemia time (40 minutes vs 28 minutes; P = .03). There were no significant differences in intraoperative blood loss (2.4 L vs 1.6 L; P = .2) or blood product transfusion requirements (packed red blood cells, 2.2 units vs 1.6 units [P = .5]; Cell Saver, 1.3 L vs 0.7 L [P = .09]). Overall complication rates did not differ significantly (27.8% for SMXC vs 44.4% for SCXC; P = .24). Thirty-day mortality rates did not differ between the two groups (0% for SMXC vs 5.6% for SCXC; P = 1). CONCLUSIONS: In this study, there were no differences in early morbidity or mortality between SMXC and SCXC during aortic reconstruction. SMXC, however, can be performed safely and effectively in properly selected patients. A larger, multicenter prospective study would help elucidate the potential benefits.

Outcomes of endovascular abdominal aortic aneurysm repair in high-risk patients.

OBJECTIVE: Although the endovascular aneurysm repair trial 2 (EVAR-2) demonstrated no benefit of EVAR in high-risk (HR) patients, EVAR is still performed widely in this patient cohort. This study compares the midterm outcomes after EVAR in HR patients with those in normal-risk (NR) patients. In turn, these data are compared with the EVAR-2 data. METHODS: A retrospective review from January 2006 to December 2013 identified 247 patients (75 HR [30.4%], 172 NR [69.6%]) who underwent elective EVAR for infrarenal aortic aneurysm in an academic tertiary institution and its affiliated Veterans Administration hospital. The same HR criteria used in the EVAR-2 trial were employed. Overall survival, graft-related complications, and reintervention rates were estimated by the Kaplan-Meier method. HR group outcomes were compared with the EVAR-2 data. RESULTS: HR patients had a larger abdominal aortic aneurysm size and had a higher prevalence of cardiac disease (P < .01), chronic obstructive pulmonary disease (P = .02), renal insufficiency (P < .01), and cancer (P < .01). Use of aspirin (63% HR vs 66% NR; P = .6), statin (83% HR vs 72% NR; P = .2), and beta-blockers (71% HR vs 60% NR; P = .2) was similar; in the EVAR-2 trial, the corresponding use of these medications was 58%, 42%, and not available, respectively. Perioperative mortality (0% HR vs 1.2% NR; P = 1.0) and early complication rates (4% HR vs 6% NR; P = .8) were similar. In contrast, perioperative mortality in the EVAR-2 trial was 9%. At a mean follow-up of 3 years, the incidence rates of delayed secondary interventions for aneurysm- or graft-related complications were 7% for HR patients and 10% for NR patients (P = .5). The 1-, 2-, and 4-year survival rates in HR patients (85%, 77%, 65%) were lower than those in NR patients (97%, 97%, 93%; P < .001), but this was more favorable compared with a 36% 4-year survival in the EVAR-2 trial. No difference was seen in long-term reintervention-free survival in HR and NR patients (P = .8). Backward stepwise logistic regression analysis identified five prognostic indicators for post-EVAR death: age, chronic kidney disease stages 4 and 5, congestive heart failure, home oxygen use, and current cancer therapy. CONCLUSIONS: EVAR can be performed in patients unfit for open surgical repair with excellent early survival and long-term durability. These outcomes in the HR group compare more favorably to the EVAR-2 trial data. However, not all HR patients for open surgical repair derive the benefit from EVAR. The decision to proceed with EVAR in HR patients should be individualized, depending on the number and severity of risk factors.

Tea Consumption and Endometrial Cancer Risk: Meta-Analysis of Prospective Cohort Studies.

Several lines of evidence suggest that tea consumption may reduce the risk of endometrial cancer due to antioxidant properties of tea, but the results of prospective data to date are inconsistent. We thus conducted a meta-analysis of prospective cohort studies to examine the relationship between tea consumption and endometrial cancer risk, using a random-effects model. We identified 5 eligible cohort studies, which included 231,870 female participants and 1831 cases for endometrial cancer. The pooled relative risk (RR) for the highest (median 2 cups/day) vs. no/lowest category of tea consumption on endometrial cancer risk was 0.95 [95% confidence interval (CI): 0.80-1.12] with no significant heterogeneity (P for heterogeneity = 0.68, I(2) = 0.0%). By country of origin, the pooled RR of 3 studies conducted in the United States was 1.00 (95% CI: 0.83-1.21), in which black tea was consumed by most people. Because of limited data on Asian population, the association of green tea on endometrial cancer was not calculated separately. There was no indication of publication bias (Begg's P = 0.46; Egger's P = 0.43). Our findings from prospective data do not support a role of tea consumption in endometrial carcinogenesis. More prospective cohort studies with green tea consumption should be conducted.

Sex Differences in Heart Rate Variability and Vascular Function Following High-Intensity Interval Training in Young Adults.

High-intensityintervaltraining (HIIT) issuperiortoothertrainingstrategies in both male andfemalehealthyindividuals. Understanding sex-specificdifferences in cardiac auto-regulation maycontributetothe optimal trainingstrategiesfor HIIT. The presentstudyaimedtoidentifysexdifferences in heart rate variability (HRV) andvascularfunctionfollowing HIIT in youngadults. Twenty-fourphysicallyactiveyoung male andfemaleadults (M: 12, F: 12, age: 19.5 yr, BMI: 22.1 kg·m-2) volunteeredtoparticipate in thestudy. Participantsperformed 10 boutsof HIIT including 20 s of high-intensitycycling at 115-130% Wmaxfollowedby 100 s ofrecovery. The cardiac auto-regulationsincluding HRV andvascularfunctionweremeasured at five different time points. The R-R interval, rMSSD, and SDNN wererecoveredfaster in malesthan in females after 15 min of HIIT. Thereweresexdifferences in theautonomicnervoussystemwhereln LF andln HF activitiesalongwithsympathovagalbalance (ln LF/HF) weregreater in femalescomparedwithmalesimmediatelyand 15 min after HIIT. However, nosignificantdifferences in bloodpressureand brachial-ankle pulse wavevelocitywereobservedbetween male andfemaleparticipants. Overall, HRV was moreactivated in femalesthan in malesfollowing HIIT, but theacuteresponse in vascularfunction was not different betweensexes. In futurestudies, sex-specificadaptationsofcardiacautoregulationfollowingrepeated HIIT mayneedtobeperformed.

Assessing the feasibility, acceptability, and preliminary efficacy of a novel symptom management care delivery intervention for caregivers receiving home hospice care: The I-HoME protocol.

BACKGROUND: Terminally ill patients experience high symptom burden at the end of life (EoL), even when receiving hospice care. In the U.S., family caregivers play a critical role in managing symptoms experienced by patients receiving home hospice services. Yet, most caregivers don't receive sufficient support or formal training in symptom management. Therefore, providing additional visits and education to caregivers could potentially improve outcomes for both patient and caregiver. In response, we developed the Improving Home hospice Management of End-of-life issues through technology (I-HoME) intervention, a program designed for family caregivers of home hospice patients. This paper describes the intervention, study design, and protocol used to evaluate the intervention. METHODS: The I-HoME study is a pilot randomized controlled trial aimed at reducing patient symptom burden through weekly tele-visits and education videos to benefit the patient's family caregiver. One hundred caregivers will be randomized to hospice care with (n = 50) or without (n = 50) the I-HoME intervention. Primary outcomes include intervention feasibility (e.g., accrual, attrition, use of the intervention) and acceptability (e.g., caregivers' comfort accessing the tele-visits and satisfaction). We will also examine preliminary efficacy using validated patient symptom burden and caregiver outcome measures (i.e., burden, depression, anxiety, satisfaction). CONCLUSION: The trial is evaluating a novel symptom management intervention that supports caregivers of patients receiving home hospice services. The intervention employs a multi-pronged approach that provides needed services at a time when close contact and support is crucial. This research could lead to advances in how care gets delivered in the home hospice setting.

Interventions for Family Caregivers of Patients Receiving Palliative/Hospice Care at Home: A Scoping Review.

There is a need for understanding the breadth of interventions for caregivers of individuals receiving hospice care at home, given the important role caregivers play in caring and the negative outcomes (e.g., depression) associated with their caregiving. Previous reviews were limited in scope to certain types of interventions or patient populations. The objective of this scoping review was to broadly examine the interventions targeting caregivers who provide care to terminally ill patients in home, with the purpose of (1) describing the characteristics of these interventions, (2) discussing key outcomes, limitations, and knowledge gaps, (3) highlighting intervention strengths, and (4) proposing future research directions. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Intervention studies that met the inclusion criteria and that were published up until October 2022 were obtained from the following databases: Ovid MEDLINE, Ovid EMBASE, CINAHL (EBSCO), and The Cochrane Library (Wiley). We analyzed 76 studies describing 55 unique interventions that took place in 14 countries. Interventions were largely delivered by nurses (n = 18, 24%), followed by an interdisciplinary team (n = 16, 21%), a health care provider (n = 10, 13%), research staff (n = 10, 13%), social worker (n = 5, 7%), and others (n = 11, 15%). Six interventions (8%) were self-administered. The most measured outcome was caregiver quality of life (n = 20, 26%), followed by anxiety (n = 18, 24%) and burden (n = 15, 20%). Missing data on patient and caregiver characteristics (i.e., age, gender) were common, and less than half of studies (n = 32, 42%) reported race/ethnicity data. Our review highlighted the current state of interventions for caregivers of patients receiving hospice care at home. Many of the interventions were in the early phases of development, raising the need for future studies to look at efficacy, effectiveness, and the ability to implement interventions in real-world settings.

An Ultramicroporous Graphene-Based 3D Structure Derived from Cellulose-Based Biomass for High-Performance CO2 Capture.

The use of powered activated carbon is often limited by inconsistent particle sizes and porosities, leading to reduced adsorption efficiencies. In this study, we demonstrated a practical and environmentally friendly method for creating a 3D graphene nanostructure with highly uniform ultramicropores from wood-based biomass through a series of delignification, carbonization, and activation processes. In addition, we evaluated the capture characteristics of this structure for CO2, CH4, and N2 gases as well as its selectivity for binary-mixture gases. Based on textural and chemical analyses, the delignified monolith had a lamellar structure interconnected by cellulose-based fibers. Interestingly, applying the KOH vapor activation technique solely to the delignified samples led to the formation of a monolithic 3D network composed of interconnected graphene sheets with a high degree of crystallinity. Especially, the Act. 1000 sample exhibited a specific surface area of 1480 m2/g and a considerable pore volume of 0.581 cm3/g, featuring consistently uniform ultramicropores over 90% in the range of 3.5-11 Å. The monolithic graphene-based samples, predominantly composed of ultramicropores, demonstrated a notably heightened capture capacity of 6.934 mol/kg at 110 kPa for CO2, along with favorable selectivity within binary gas mixtures (CO2/N2, CO2/CH4, and CO2/CH4). Our findings suggest that this biomass-derived 3D structure has the potential to serve as a monolithic adsorbent in gas separation applications.

Pilot Testing Educational Videos for Black Caregivers Receiving Home Hospice Care.

Black caregivers face distinct challenges in symptom management when providing end-of-life care. Educational interventions may improve caregiver preparedness and competency by providing information on symptom management. This study pilot tested 4 culturally tailored caregiver educational videos about symptom management for Black caregivers receiving home hospice care at a large, urban, nonprofit hospice organization to determine feasibility and acceptability, along with their potential impact on caregiver outcomes. All participants (N = 10) agreed to watch the 4 videos and found the videos to be helpful; 90% (n = 9) shared that they would recommend them to other Black caregivers receiving home hospice care. Total preparedness scores increased from a mean score of 23.5 preintervention to 28.3 postintervention. Caregiver competency scores increased from 13.8 at preintervention to 14.3 at postintervention. Caregivers' comfort and knowledge scores increased from preintervention to postintervention for all 7 end-of-life topics presented in the 4 videos. This study found that it was feasible and acceptable to show Black caregivers culturally tailored educational videos related to issues regarding symptom management. Many found the videos to be helpful and the topics to be relatable. There were trends toward improvement in preparedness and competency. Future studies examining efficacy are needed to determine the impact of this intervention.

What Motivates Physicians to Address Caregiver Needs? The Role of Experiential Similarity.

Despite the significant stress of family caregiving, caregivers' needs and risks are often overlooked in healthcare settings. This study examined the factors associated with primary care physicians' perceived responsibility to identify and address caregiver needs and risks. Using a national random sample of U.S. primary care physicians (N = 106), multivariable logistic regression analyses were conducted to examine associations of physicians' perceived responsibility to assess caregivers' needs with experiential similarity (personal experience with caregiving), structural similarity (being older and female), and secondary exposure variables (time seeing older adults in the outpatient setting). Most (76.5%) physicians felt responsible for identifying caregivers' needs and risks. In multivariable models, physicians who had personal experience with caregiving were four times more likely than those without it to feel responsible for identifying caregivers' needs and risks and assessing caregivers' mental health concerns. Thus, physicians may benefit from educational interventions that immerse them in caregivers' lived experiences.

Recruitment of family caregivers of persons with dementia: Lessons learned from a pilot randomized controlled trial.

Family caregivers play an essential role in supporting the health and well-being of older adults with dementia, a population projected to increase rapidly over the coming decades. Enrolling caregivers of people with dementia (PWD) in research studies is vital to generating the evidence necessary to support broader implementation of efficacious intervention programs in real-world care delivery, but a range of challenges impede recruitment and enrollment of sufficiently large and representative sample sizes. In this article, we characterize the challenges and lessons learned from recruiting caregivers of PWD to participate in a pilot randomized control trial. We utilize Bronfenbrenner's ecological model to categorize the challenges into three levels: individual (i.e., understanding caregivers' time constraints and motivations), community (i.e., reaching underrepresented populations and accessing caregiver support groups) and institutional (i.e., obtaining informed consent and navigating research registries). We found that establishing rapport and maintaining flexibility with participants was crucial for motivating individuals to enroll in our study. Building trust with local communities by collaborating with support group leaders, appointing a co-investigator who is already embedded within a given community, and establishing equitable partnerships with organizations increased recruitment rates. At the institutional level, engaging experts in regulatory affairs and geriatrics may help overcome barriers in obtaining approval from institutional review boards. We also recommend using research registries of individuals who offer their contact information to researchers. The lessons learned from our research-including the challenges and potential solutions to overcome them-may promote more effective and efficient recruitment in future research.

Black Caregivers' Symptom Management, Cultural, and Religious Experiences With Home Hospice Care.

CONTEXT: Informal Black or African American (Black/AA) caregivers are at high risk for caregiver burden due to both greater caregiving responsibilities and unmet needs. However, there has been minimal research on the challenges Black/AA caregivers face after hospice enrollment. OBJECTIVES: This study seeks to address this knowledge gap by applying qualitative methods to understand Black/AA caregivers' experiences around symptom management, cultural, and religious challenges during home hospice care. METHODS: Data from small group discussions with 11 bereaved Black/AA caregivers of patients who received home hospice care were qualitatively analyzed. RESULTS: Caregivers struggled most with managing patients' pain, lack of appetite, and decline near end of life (EoL). Cultural needs (e.g., knowing their language, having familiarity with foods) were perceived as not on top of mind for many Black/AA caregivers. However, there was a concern of stigma around mental health preventing care recipients from sharing their mental health concerns and seeking resources. Many caregivers relied on their personal religious networks rather than services provided by hospice chaplains. Lastly, caregivers reported increased burden during this phase of caregiving but were satisfied with the overall hospice experience. CONCLUSION: Our results suggest that tailored approaches that target mental health stigma in the Black/AA community and reduce caregiver distress around end of life symptoms may improve hospice outcomes among Black/AA hospice caregivers. Hospice spiritual services should consider offering services complementary to caregivers' existing religious networks. Future qualitative and quantitative studies should examine the clinical implications of these results in terms of patient, caregiver, and hospice outcomes.

Artificial intelligence in urologic oncology: the actual clinical practice results of IBM Watson for Oncology in South Korea.

Background: Artificial intelligence (AI) is changing our life, including the medical field. Repeated machine learning using big data made various fields more predictable and accurate. In medicine, IBM Watson for Oncology (WFO), trained by Memorial Slone Kettering Cancer Center (MSKCC), was first introduced and applied in 14 countries worldwide.Our study was designed to assess the feasibility of WFO in actual clinical practice. We aimed to investigate the concordance rate between WFO and multidisciplinary tumor board (MTB) in Urologic cancer patients. Materials and methods: We reviewed retrospectively collected data for consecutive patients who underwent WFO and MTB simultaneously in the diagnosis of urologic malignancy before determining further treatment between August 2017 and September 2020. We compared the recommendation of the AI system, WFO (IBM Watson Health, Cambridge, MA), with the opinion of MTB for further managing all patients diagnosed with urologic malignancies such as prostate, bladder, and kidney cancer. Results: A total of 55 patients were enrolled in our study. The number of patients with prostate cancer was 48. The number of bladder and kidney cancer patients was 5 and 2, respectively. The overall concordance rate between WFO and MTB was 92.7%. Three patients could not suggest proper treatment options using WFO, and the recommended choice of WFO was not feasible in the Korean Health Insurance Review and Assessment Service. Conclusions: The decision of WFO showed a high concordance rate with a multidisciplinary tumor board for urologic oncology. However, some recommendations of WFO were not feasible in actual practice, and WFO still has some points to improve and modify. Interestingly, applying WFO is likely to facilitate a multidisciplinary team approach.

High-Performance Electrochromic Devices Based on Size-Controlled 2D WO3 Nanosheets Prepared Using the Intercalation Method.

It is difficult to obtain ultrathin two-dimensional (2D) tungsten trioxide (WO3) nanosheets through direct exfoliation from bulk WO3 in solution due to the strong bonding between interlayers. Herein, WO3 nanosheets with controllable sizes were synthesized via K+ intercalation and the exfoliation of WO3 powder using sonication and temperature. Because of the intercalation and expansion in the interlayer distance, the intercalated WO3 could be successfully exfoliated to produce a large quantity of individual 2D WO3 nanosheets in N-methyl-2-pyrrolidone under sonication. The exfoliated ultrathin WO3 nanosheets exhibited better electrochromic performance in an electrochromic device than WO3 powder and exfoliated WO3 without intercalation. In particular, the prepared small WO3 nanosheets exhibited excellent electrochromic properties with a large optical modulation of 41.78% at 700 nm and fast switching behavior times of 9.2 s for bleaching and 10.5 s for coloring. Furthermore, after 1000 cycles, the small WO3 nanosheets still maintained 86% of their initial performance.

Feasibility and measurement stability of smartwatch-based cuffless blood pressure monitoring: A real-world prospective observational study.

Cuffless wearable devices are currently being developed for long-term monitoring of blood pressure (BP) in patients with hypertension and in apparently healthy people. This study evaluated the feasibility and measurement stability of smartwatch-based cuffless BP monitoring in real-world conditions. Users of the first smartwatch-based cuffless BP monitor approved in Korea (Samsung Galaxy Watch) were invited to upload their data from using the device for 4 weeks post calibration. A total of 760 participants (mean age 43.7 ± 11.9, 80.3% men) provided 35,797 BP readings (average monitoring 22 ± 4 days [SD]; average readings 47 ± 42 per participant [median 36]). Each participant obtained 1.5 ± 1.3 readings/day and 19.7% of the participants obtained measurements every day. BP showed considerable variability, mainly depending on the day and time of the measurement. There was a trend towards higher BP levels on Mondays than on other days of the week and on workdays than in weekends. BP readings taken between 00:00 and 04:00 tended to be the lowest, whereas those between 12:00 and 16:00 the highest. The average pre-post calibration error for systolic BP (difference in 7-day BP before and after calibration), was 6.8 ± 5.6 mmHg, and was increased with higher systolic BP levels before calibration. Smartwatch-based cuffless BP monitoring is feasible for out-of-office monitoring in the real-world setting. The stability of BP measurement post calibration and the standardization and optimal time interval for recalibration need further investigation.

Endovascular repair of ruptured abdominal aortic aneurysm does not confer survival benefits over open repair.

OBJECTIVE: Endovascular repair of ruptured abdominal aortic aneurysm (rAAA) is being increasingly performed despite lack of good evidence for its superiority. Other reported studies suffer from patient selection and publication bias with limited follow-up. This study is a single-center propensity score comparing early and midterm outcomes between open surgical repair (OSR) and endovascular repair of rAAA (REVAR). METHODS: A retrospective review from January 2001 to November 2010 identified 312 patients who underwent rAAA repairs. Thirty-one patients with antecedent AAA repair and three with incomplete records were excluded, leaving 37 REVARs and 241 OSRs. Propensity score-based matching for sex, age, preoperative hemodynamic status, surgeon's annual AAA volume, and preoperative cardiopulmonary resuscitation was performed in a 1:3 ratio to compare outcomes. Thirty-seven REVARs were matched with 111 OSRs. Late survival was estimated by Kaplan-Meier methods. RESULTS: Operative time and blood replacement were higher with OSR. Overall complication rates were similar (54% REVAR vs 66% OSR; P = .23), except for higher incidences of tracheostomies (21% vs 3%; P = .015), myocardial infarction (38% vs 18%; P = .036), and acute tubular necrosis (47% vs 21%; P = .009) with OSR. Operative mortality rates were similar (22% REVAR vs 32% OSR), with an odds ratio of 0.63 for REVAR (95% confidence interval = [0.24, 1.48]; P = .40). No differences in the incidences for secondary interventions for aneurysm- or graft-related complications were noted (22% REVAR vs 22% OSR; P = .99). Kaplan-Meier estimates of 1-, 2-, and 3-year survival rates were also similar (50%, 50%, 42% REVAR vs 54%, 52%, 47% OSR; P = .66). CONCLUSIONS: REVAR for rAAA does not seem to conclusively confer either acute or late survival advantages. Routine use of REVAR should be deferred until prospective, randomized trial data become available.

Delayed open conversions after endovascular abdominal aortic aneurysm repair.

OBJECTIVE: Secondary interventions after endovascular aneurysm repair (EVAR) remain a concern. Most are simple catheter-based procedures, but in some instances, open conversions (OCs) are required and carry a worse outcome. We reviewed our experience to characterize these OCs. METHODS: A retrospective review was conducted of all patients who underwent an OC after a previous EVAR for an aneurysm-related indication from 2001 to 2010. Clinical outcomes are reported. RESULTS: Data were reviewed for 44 patients (77% men) with a mean age of 74 years (range, 55-90 years). The average time from EVAR to the first OC was 45 months (range, 2-190 months). In six patients (14%), the initial EVAR was at another institution. The endografts used were Ancure in 16, Excluder in 13, AneuRx in eight, Zenith in three, Lifepath in one, Renu in one, and undetermined in two. Twenty-two patients had previously undergone a total of 32 endovascular reinterventions before their index OC. Indications for OC were aneurysm expansion in 28 (64%), rupture in 12 (27%), and infection in four (9%). The endograft was preserved in situ in 10 patients (23%). Explantation was partial in 18 (41%) or complete in 16 (36%). Endograft preservation was used for type II endoleak in all but one patient by selective ligation of the culprit arteries (lumbar in four, inferior mesenteric artery in five, and middle sacral in one). Proximal neck banding was performed in one type Ia endoleak. Overall morbidity was 55%, and mortality was 18%. No deaths occurred in a subgroup of patients who underwent endograft preservation with selective ligation of culprit vessels for type II endoleak. Intraoperative complications included bowel injury in two, bleeding in two, splenectomy in one, and ureteral injury in one. At a mean follow-up of 20 months, two patients underwent additional procedures after the index OC: one after endograft preservation and one after partial explantation. None of the patients who underwent elective OC with endograft preservation required subsequent endograft explantation. CONCLUSIONS: Most OCs after EVAR are associated with significant morbidity and mortality, except when electively treating an isolated type II endoleak with ligation of branches and preservation of the endograft.

Bayesian nonparametric inference on quantile residual life function: Application to breast cancer data.

There is often an interest in estimating a residual life function as a summary measure of survival data. For ease in presentation of the potential therapeutic effect of a new drug, investigators may summarize survival data in terms of the remaining life years of patients. Under heavy right censoring, however, some reasonably high quantiles (e.g., median) of a residual lifetime distribution cannot be always estimated via a popular nonparametric approach on the basis of the Kaplan-Meier estimator. To overcome the difficulties in dealing with heavily censored survival data, this paper develops a Bayesian nonparametric approach that takes advantage of a fully model-based but highly flexible probabilistic framework. We use a Dirichlet process mixture of Weibull distributions to avoid strong parametric assumptions on the unknown failure time distribution, making it possible to estimate any quantile residual life function under heavy censoring. Posterior computation through Markov chain Monte Carlo is straightforward and efficient because of conjugacy properties and partial collapse. We illustrate the proposed methods by using both simulated data and heavily censored survival data from a recent breast cancer clinical trial conducted by the National Surgical Adjuvant Breast and Bowel Project.