Risk of Major Malformations in Infants After First-Trimester Exposure to Stimulants: Results From the Massachusetts General Hospital National Pregnancy Registry for Psychiatric Medications.

PURPOSE/BACKGROUND: The prevalence of attention-deficit/hyperactivity disorder in adult females is 3% to 4%. Attention-deficit/hyperactivity disorder is highly comorbid with other psychiatric disorders such as mood, anxiety, and substance use disorders. For reproductive-aged women, the treatment of attention-deficit/hyperactivity disorder with stimulant medications may be considered during pregnancy or breastfeeding, although historically, data are lacking to inform these decisions. The aim of this investigation was to determine the risk of major malformations in infants after first-trimester prescription stimulant exposure in a small but rigorously characterized sample. METHODS/PROCEDURES: The Massachusetts General Hospital National Pregnancy Registry for Psychiatric Medications systematically ascertains information from pregnant females including demographic information, medical and psychiatric history, use of prescription medications, and other information relevant to fetal outcomes. Participants provide verbal informed consent and are interviewed twice during gestation and again at approximately 3 months postpartum. The primary outcome of interest is the presence of a major malformation identified within 6 months after birth. Redacted cases of major malformations are reviewed by a dysmorphologist blinded to medication exposure. FINDINGS/RESULTS: A total of N = 1988 women were eligible for this analysis, including the following exposures: n = 173 to mixed amphetamine salts; n = 40 to lisdexamfetamine; n = 45 to methylphenidate; n = 3 to dexmethylphenidate; and n = 1755 controls. The odds ratio of a major malformation among infants after first-trimester exposure to any stimulant was 0.39 (95% confidence interval, 0.09-1.61) compared with controls. There were no major malformations observed in infants exposed to lisdexamfetamine, methylphenidate, or dexmethylphenidate. IMPLICATIONS/CONCLUSIONS: Although preliminary, this analysis from an ongoing pregnancy registry provides reassurance that these stimulants do not appear to have major teratogenic effects. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01246765 .

Risk of Major Malformations Following First-Trimester Exposure to Olanzapine: Preliminary Data From the Massachusetts General Hospital National Pregnancy Registry for Psychiatric Medications.

PURPOSE/BACKGROUND: Since its US Food and Drug Administration approval in 1996, olanzapine has been one of the most commonly prescribed atypical antipsychotics, making a better understanding of its reproductive safety profile critical. The goal of the current analysis was to determine the risk of major malformations among infants exposed to olanzapine during pregnancy compared with a group of nonexposed infants. METHODS/PROCEDURES: The National Pregnancy Registry for Psychiatric Medications is a prospective pharmacovigilance program in which pregnant women are enrolled and interviewed during pregnancy and the postpartum period. Labor and delivery and pediatric medical records were screened for evidence of major malformations followed by adjudication by a dysmorphologist blinded to medication exposure. Infants with first-trimester exposure to olanzapine were compared with controls without second-generation antipsychotic exposure. FINDINGS/RESULTS: As of April 18, 2022, 2619 women have enrolled in the study. At the time of data extraction, 49 olanzapine-exposed infants and 1156 infants in the comparison group were eligible for these analyses. There were no major malformations associated with olanzapine exposure in the first trimester. The absolute risk for major malformations in the exposure group was 0.00% (95% confidence interval, 0.00-7.25) for olanzapine compared with 1.64% (95% confidence interval, 0.99-2.55) in the control group. IMPLICATIONS/CONCLUSIONS: In this prospective cohort, no major malformations were associated with olanzapine exposure during the first trimester. Although these data are preliminary and cannot rule out more modest effects, they are nonetheless important, adding to the growing reproductive safety data for olanzapine.

Risk of Poor Neonatal Adaptation Syndrome Among Infants Exposed to Second-Generation Atypical Antipsychotics Compared to Antidepressants: Results From the National Pregnancy Registry for Psychiatric Medications.

Objective: While poor neonatal adaptation syndrome (PNAS) has been particularly well described among infants exposed to antidepressants, specifically selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), this is not the case for second-generation antipsychotics (SGAs). In 2011, the US Food and Drug Administration (FDA) issued a drug safety warning regarding fetal antipsychotic exposure and risk for PNAS and extrapyramidal symptoms (EPS). The primary objective of this study was to examine the risk for PNAS among infants exposed to SGAs compared to SSRI/SNRI-exposed infants, leveraging the prospective, longitudinal design of the National Pregnancy Registry for Psychiatric Medications (NPRPM).Methods: The NPRPM is a prospective pharmacovigilance program in which pregnant women, aged 18-45 years, are enrolled and followed prospectively. Medical records were systematically reviewed and data abstracted using a checklist of PNAS and EPS symptoms specifically outlined in the FDA drug safety warning. The two study groups included infants exposed to an SGA during pregnancy and infants exposed to an SSRI/SNRI during pregnancy. The primary outcome was the presence of at least one or more PNAS symptoms during the first month of life. Other neonatal outcomes following exposure to the medication of interest, including preterm birth, neonatal intensive care unit (NICU) admission, rates of EPS, and whether infants were discharged home with their mothers, are also reported.Results: Of the 2,145 women enrolled in this study as of December 16, 2020, a total of 373 women and their infants (n = 384) were eligible for inclusion (n = 193 SGA-exposed infants and 191 SSRI/SNRI-exposed infants). Among SGA-exposed infants, 32.6% (63/193) experienced at least 1 PNAS sign compared to 34.6% of infants (66/191) in the SSRI/SNRI-exposed group. The majority of infants in each group showed no symptoms of PNAS. No differences were observed between the two groups with respect to rates of preterm birth, NICU admission, prevalence of EPS, and timing of infants being discharged home with their mothers.Conclusions: PNAS symptomatology was comparable among infants exposed prenatally to an SGA or to an SSRI/SNRI. These preliminary findings provide an estimated risk of PNAS among infants exposed to SGAs of roughly 30%. Interestingly, these findings are also consistent with estimates in the literature of PNAS in SSRI/SNRI-exposed infants, suggesting a possible common pathway underlying this phenomenon.Trial Registration: ClinicalTrials.gov identifier: NCT01246765.

Reproductive Safety of Lurasidone and Quetiapine: Update from the National Pregnancy Registry for Psychiatric Medications.

Background: Second-generation antipsychotics (SGAs), also called atypical antipsychotics, are common therapies for women with a spectrum of psychiatric disorders. No systematically ascertained human reproductive safety data are available for lurasidone, and prospective data for quetiapine are limited, making decisions regarding use of these medications during pregnancy complicated. Materials and Methods: The National Pregnancy Registry for Psychiatric Medications is a prospective cohort study designed to collect reproductive safety data relative to SGAs. Pregnant women aged 18-45 years, with psychiatric illness and prenatal psychotropic medication exposure completed three phone interviews during pregnancy and the postpartum period. Cases of presumed malformations are abstracted from medical records for adjudication by a teratologist blinded to medication exposure. Results: Of 2,293 women enrolled at the time of analysis, 134 in the lurasidone group, 264 in the quetiapine group, and 886 controls completed the postpartum interview and were therefore eligible for inclusion. Dropped or lost-to-follow-up participants (13%) and those currently pregnant were excluded. Participants were predominantly White, college-educated, and married (lurasidone = 88.1%, 76.9%, 77.6%; quetiapine = 89.8%, 71.2%, 75.0%; controls = 92.7%, 86.7%, 89.1%). Absolute risks of major malformations were 2.19% (lurasidone), 1.85% (quetiapine), and 1.77% (controls). Odds ratios comparing lurasidone and quetiapine with controls were 1.24 (95% confidence interval [CI] = 0.36-4.32) and 1.04 (95% CI = 0.38-2.85), respectively. Conclusions: No specific patterns of malformations were observed in infants exposed to the medications of interest. Lurasidone and quetiapine did not appear to be major teratogens, but further information is needed to refine risk estimates. Food and Drug Administration guidance underscores the importance of pregnancy registries. Clinical trial number: NCT01246765.

A deep 96-well plate RBC storage platform for high-throughput screening of novel storage solutions.

Background: Red blood cell (RBC) storage solutions, also known as additive solutions (ASs), first developed in the 1970s, enable extended storage of RBCs. Unfortunately, the advancements in this field have been limited, due to labor intensive and time-consuming serial in vitro and in vivo testing, coupled with very high commercialization hurdles. This study examines the utility of deep 96-well plates for preliminary screenings of novel ASs through comparison of RBC storage with the standard PVC bags in terms of hemolysis and ATP levels, under both normoxic (N) and hypoxic/hypocapnic (H) storage conditions. The necessity for the presence of DEHP, normally provided by PVC bags, is also examined. Materials and methods: A pool of 2 ABO compatible RBC units was split between a bag and a plate. Each plate well contained either 1, 2 or 0 PVC strips cut from standard storage bags to supply DEHP. The H bags and plates were processed in an anaerobic glovebox and stored in O2 barrier bags. Hemolysis and ATP were measured bi-weekly using standard methods. Results: Final ATP and hemolysis values for the plate-stored RBCs were comparable to the typical values observed for 6-week storage of leukoreduced AS-3 RBCs in PVC bags under both N and H conditions. Hemolysis was below FDA and EU benchmarks of 1% and 0.8%, respectively, and excluding DEHP from plates during storage, resulted in an inconsequential increase when compared to bag samples. Discussion: In combination with high-throughput metabolomics workflow, this platform provides a highly efficient preliminary screening platform to accelerate the initial testing and consequent development of novel RBC ASs.

Risk of major malformations in infants after first-trimester exposure to benzodiazepines: Results from the Massachusetts General Hospital National Pregnancy Registry for Psychiatric Medications.

BACKGROUND: Perinatal anxiety affects 20% of women, and untreated maternal mental illness can cause deleterious effects for women and their children. Benzodiazepines are commonly used to treat anxiety disorders. The reported risk of congenital malformations after in utero benzodiazepine exposure has been inconsistent. METHODS: The Massachusetts General Hospital National Pregnancy Registry for Psychiatric Medications prospectively enrolls pregnant women with psychiatric illness who take one or more psychiatric medications. Participants are interviewed twice during pregnancy and at 12 weeks postpartum. Women taking any benzodiazepine during the first trimester of pregnancy were compared with a group of women taking psychiatric medication(s) other than benzodiazepines during pregnancy. RESULTS: A total of 1053 women were eligible for this analysis; N = 151 women who had taken a benzodiazepine during the first trimester, and the comparison group was N = 902 women. There were 5 (3.21%) major malformations in the exposure group and 32 (3.46%) in the comparison group (odds ratio 0.92; 95% confidence interval 0.35-2.41). CONCLUSION: This ongoing pregnancy registry offers reassurance that benzodiazepines do not appear to have major teratogenic effects. The precision of relative risk estimate will improve as the number of participants increases. This and other pregnancy registries will better inform the reproductive safety of benzodiazepines.

Breastfeeding practices among women taking second-generation antipsychotics: findings from the National Pregnancy Registry for Atypical Antipsychotics.

The purpose of this study is to examine initiation rates of breastfeeding and other breastfeeding outcomes among women taking second generation antipsychotics (SGAs). Participants were enrolled in the National Pregnancy Registry for Atypical Antipsychotics; an ongoing prospective cohort study enrolling women age 18-45 years who are exposed and unexposed to SGAs during pregnancy. A 3-month postpartum interview collects information regarding breastfeeding behaviors. Specifically, women are asked the following questions about ever breastfeeding, still breastfeeding at 3 months postpartum, and whether women are breastfeeding exclusively, bottle-feeding exclusively, or breast and bottle feeding. Descriptive statistics were used to summarize demographic variables and breastfeeding practices. Rates of breastfeeding initiation and continuation were higher among participants who did not use SGAs. Among women not on SGAs, 88.2% of women reported "ever breastfeeding" compared to 59.3% of women on an SGA. At 3 months postpartum, 47% of women on a non-SGA were exclusively breastfeeding compared to 23% of women on an SGA. While the majority of women on an SGA initiated breastfeeding, breastfeeding rates were considerably lower than for women who were not on a SGA. More research is needed on the safety of lactation and use of combinations of psychotropics for women in pregnancy and postpartum.

The Course of ADHD during Pregnancy.

OBJECTIVE: The aim of this study was to characterize the course of ADHD during pregnancy. METHOD: Women ages 18 to 45 were followed prospectively at <20 weeks, 24 weeks, and 36 weeks pregnant. Three groups emerged: women who discontinued, maintained, or adjusted their ADHD medications. ADHD symptoms were recorded using the AISRS. Anxiety, depression, stress, and functional impairment were monitored. RESULTS: A total of 25 women with ADHD were eligible for analysis. No significant difference observed between three groups in AISRS scores. Significant differences found between medication discontinuers vs adjusters for both mood and family functioning (EPDS, 5.3, p < .0001; WFIRS, 3.3, p = .0309). Significant differences also found between discontinuers vs maintainers for mood and family functioning (EPDS, 4.98, p = .0009; WFIRS, 3.09, p = .0197). CONCLUSION: This preliminary study provides novel insight into the course of ADHD during pregnancy, underscoring mood and family functioning as critical domains that may contribute to growing use of psychostimulants during pregnancy.

The oxygen saturation of red blood cell concentrates: The basis for a novel index of red cell oxidative stress.

BACKGROUND: Oxidative stress is a major driving force in the development of storage lesions in red cell concentrates (RCCs). Unlike manufactured pharmaceuticals, differences in component preparation methods and genetic/physiological status of donors result in nonuniform biochemical characteristics of RCCs. Various characteristics of donated blood on oxygen saturation (SO2 ) distribution were investigated, and a model to estimate potential oxidative stress burden of stored RCC at transfusion is proposed. STUDY DESIGN AND METHODS: The oxygen content of freshly prepared RCCs (770) was quantified noninvasively as fractional hemoglobin saturation (SO2 ) with visible reflectance spectrometry. Using separate RCCs and mimicking typical handling of RCCs during routine storage, evolution of SO2 was followed for construction of an empirical model. Based on this model, the oxygen exposure index (OEI) was formulated to estimate the accumulated oxygen exposure burden of RCC at the time of transfusion. RESULTS: The SO2 of RCCs varied widely at donation (mean 43% ± 1.3%; range 20%-93%). Multivariate regression model showed that sex and processing method had small effects on SO2 (R2  = 0.12), indicating that variability was mainly attributed to other individual donor characteristics. Storage simulation model indicated that median SO2 increased gradually over 6 weeks (approx. 1.3 fold), while OEI increased at a faster rate (approx. eight-fold). CONCLUSION: In addition to storage age, the OEI provides a potential new metric to assess the quality of RCCs at the time of transfusion in terms of their oxidative stress. In future studies, a single noninvasive measurement during storage could link OEI to clinical outcomes in transfusion recipients.

Safety and Efficacy of a Disposable Vaginal Device for Stress Urinary Incontinence.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of an over-the-counter device for the treatment of stress urinary incontinence (SUI) in females. METHODS: A multicenter, interventional, single-arm study involving 5 different sites was conducted including women diagnosed with symptomatic SUI using a self-inserted pessary device. A 1-week baseline period was followed by a 2-week period of wearing the device. The main outcome of our study was to determine if the device was able to reduce at least 50% the number of leakage events and pad weight. RESULTS: Across all study sites, 73 subjects were enrolled and 51 completed the study. Efficacy analyses were conducted on the modified intent-to-treat population (n = 48), whereas the safety analysis was conducted on all consented participants. The average pad weight gain was 0.9 g/h at baseline and 0.5 g/h during the treatment phase. The number of leakage episodes per day decreased from 2 at baseline to 0.9 during the treatment phase (P < 0.0001). Seventy-one percent of the study population experienced a more than 50% reduction in leakage volume, leakage episodes, or both. The quality of life scores improved from baseline to posttreatment phase by 4.35 points on average (P < 0.0001). A total of 40 adverse events were recorded, and only 4 subjects withdrew due to adverse events. CONCLUSIONS: The self-deployable pessary device evaluated in this study is an alternative option for women seeking an over-the-counter method to manage symptoms of SUI. Further studies are required to determine the long-term effects and compliance using the device.

Variation in resource utilization associated with the surgical management of ovarian cancer.

OBJECTIVE: Identify the major factors that drive standardized cost in providing surgical care for women with ovarian cancer, characterize the magnitude of variation in resource utilization between centers, and to investigate the relationship between resource utilization and quality of care provided. METHODS: Retrospective cohort study of hospitals across the United States reporting to the Premier Database who cared for patients with ovarian cancer diagnosed between 2007 and 2014. The primary outcome was standardized total cost of the index hospitalization. To assess the relationship between hospital standardized costs and patient outcomes, we identified four measures of quality: 1) complications, 2) re-operation, 3) length of stay > 15 days, and 4) unplanned readmission. RESULTS: The study population included 15,857 patients treated at 226 hospitals. The median standardized cost for hospitalizations was $13,267 (IQR = $3342). Reoperation was associated with 49% increase (95% CI = 43%-56%), and having minor complication was associated with 10% (95% CI = 8%-12%) increase in standardized cost, a moderate complication was associated with 36% (95% CI = 33%-38%) increase, and a major complication was associated with 83% (95% CI = 76%-89%) increase. The average risk-adjusted hospital standardized costs for hospitals in the highest resource use quartiles was 56% higher than the average hospital costs for hospitals in the lowest quartile ($10,826 vs. $16,933). The largest variation was in operating room standardized cost (45.5% of the total variation in operating room cost is explained by differences in hospital practices) and supplies (41.7%). CONCLUSIONS: We identified significant variation in standardized costs among women who underwent surgery for ovarian cancer, operating room and supply costs are the largest drivers of variation.

Influence of diabetes and perivascular allogeneic endothelial cell implants on arteriovenous fistula remodeling.

OBJECTIVES: Arteriovenous fistula (AVF) is the preferred type of vascular access for hemodialysis to treat end-stage renal disease. A high proportion of AVF are never used for dialysis because the vein fails to mature adequately. We have previously described the safety and feasibility of Vascugel (Genzyme BioSurgery, Cambridge, Mass) (allogeneic aortic endothelial cells in a gelatin matrix) when placed around the anastomotic and venous outflow sites of AVFs (Vascular intimal Hyperplasia: Extending Arterial and venous patency, Limiting vascular Trauma, and inhibiting Hyperplasia while re-establishing vascular health [V-HEALTH] clinical study). In this retrospective analysis, we investigated factors that influenced AVF remodeling in patients from the V-HEALTH study. We hypothesized that providing healthy endothelial cells and their secreted factors immediately after surgery could enhance venous remodeling in the setting of vascular injury. METHODS: Thirty-one AVF patients from the V-HEALTH study were randomized 2:1 to receive either Vascugel or control matrices (placebo) at surgery and were followed for 24 weeks. Venous lumen diameter was measured by ultrasound at 1, 3, and 5 cm from the anastomosis. Vein remodeling (change in lumen diameter at 4, 12, and 24 weeks compared with baseline diameter at 2 weeks) was analyzed using a multiple regression mixed model. RESULTS: The results indicated that diabetes was a significant, negative predictor of venous remodeling over the 24-week study (P = .02). The model-predicted change in lumen diameter from 2 to 24 weeks was -0.7 mm in diabetic patients (n = 11) and +2.4 mm in nondiabetic patients (n = 15), a difference of 3.1 mm, 95% confidence interval [CI] (1.4-4.9), P = .0014. Patient race, baseline vein diameter, and time post-AVF creation were also significant factors that affected remodeling (P < .05). Compared with placebo, there was a strong suggestion that Vascugel treatment improved the rate of venous enlargement in diabetic patients (P = .05). The model-predicted change in lumen diameter at 24 weeks was -1.9 mm for placebo-treated diabetic patients and +0.4 mm for Vascugel-treated diabetic patients, a difference of 2.3 mm, 95% CI (-0.1-4.8), P = .06, suggesting that treatment with Vascugel may mitigate the negative influence of diabetes on AVF remodeling. CONCLUSIONS: Diabetes negatively impacts AVF remodeling and targeted local therapy with perivascular, allogeneic endothelial cells may ameliorate this effect. A phase II trial designed specifically to evaluate AVF remodeling is needed to determine if Vascugel can increase AVF maturation and use and to support larger randomized trials.

Longitudinal trends and influence of BMI mismatch in living kidney donors and their recipients.

BACKGROUND AND OBJECTIVES: Age and body mass index (BMI) of kidney donors and recipients affect kidney allograft outcomes. Moreover, while deceased donor and recipient body size mismatch have been reported to influence allograft outcomes, how BMI mismatch in living kidney donor-recipient pairs affect graft survival is not well defined. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: We investigated trends in characteristics of 90,815 US. living kidney donors and their recipients between 1987 and 2008. RESULTS: Median ages of donors and their recipients have risen over time, and the proportion of living donors age ≥ 50 years increased from 11 to 25%. Median BMI of recipients increased from 22.6 to 26.6 kg/m(2); median BMI of kidney donors for the past 5 years has been 26.4 kg/m(2). Only 35% of living donor-recipient pairs were in the same BMI category (<25, 25-29.9, 30-34.9, or ≥ 35 kg/m(2)). BMI mismatch where the living donor was three categories heavier than the recipient was associated with a significant adjusted risk for death-censored allograft loss (HR 2.31, 95% CI 1.05-5.08). CONCLUSIONS: Living kidney donors are donating at more advanced ages, and the majority are overweight or obese in recent years. In summary: (1) previous longitudinal studies of living kidney donor outcomes may not be generalizable to recent donors, and studies of contemporary living kidney donor cohorts may be informative, (2) the majority of living donor-recipient pairs have BMI mismatch, and (3) extreme BMI mismatch where the living donor is heavier may confer an independent risk for allograft loss.

Multicenter phase I/II trial of the safety of allogeneic endothelial cell implants after the creation of arteriovenous access for hemodialysis use: the V-HEALTH study.

OBJECTIVES: Vascular access dysfunction is the major cause of morbidity in patients on hemodialysis to treat end stage renal disease. Preclinical studies have demonstrated that the perivascular placement of implants containing allogeneic aortic endothelial cells (Vascugel) reduces thrombosis, inflammation, stenosis and increases lumen diameter in porcine models of arteriovenous fistulae (AVF) and arteriovenous grafts (AVG). We conducted a phase I/II clinical study to investigate the safety of Vascugel placement around the surgical anastomotic sites of newly constructed dialysis accesses. METHODS: From July 2006 to August 2006, eight patients (4 AVG, 4 AVF) were treated with two Vascugel sponges at the venous anastomosis in the open-label phase I trial. From January 2007 to August 2007 57 patients (30 AVG and 27 AVF) were randomized in a 2:1 fashion to receive either Vascugel or control matrices (placebo) at surgery. The phase II AVG patients had sponges placed at both the venous and arterial anastomoses. All patients were followed for 24 weeks. The primary objective of the study was to demonstrate the safety (incidence of infection, intervention, and thrombosis) of Vascugel compared with placebo within 30 days post-surgery. Secondary endpoints included assessments of patency, lumen diameter, and immunologic sensitization to human leukocyte antigens (HLA) determined by measurement of panel reactive antibodies (PRA). RESULTS: There was no difference in early complication rates between the Vascugel and placebo groups at 4 weeks (10.9% vs 21.1%, respectively). There were no statistically significant differences in primary or assisted primary patency between the intent to treat groups at 24 weeks. Vascugel treated AVG had a primary patency rate of 38% and an assisted primary patency rate of 72% (vs 23% and 58%, respectively, for placebo). Vascugel treated AVF had a primary patency rate of 60% at 24 weeks and an assisted primary patency rate of 96% (vs 62% and 88%, respectively, for placebo). A greater than 30% increase in PRA was detected in 9 of the 46 (19.5%) Vascugel treated patients and one of the 19 (5.2%) placebo patients (P = .26) and was not associated with any evidence of local or systemic complications. CONCLUSIONS: Targeted local therapy with perivascular, allogeneic endothelial cells is a safe and novel therapeutic approach that may be ideally suited to control the response to injury at surgical anastomoses. Larger randomized trials are needed to determine if Vascugel can prolong AVG or AVF patency.

Shielding of the hip prosthesis during radiation therapy for heterotopic ossification is associated with increased failure of prophylaxis.

PURPOSE: Radiation therapy (RT) is frequently administered to prevent heterotopic ossification (HO) after total hip arthroplasty (THA). The purpose of this study was to determine if there is an increased risk of HO after RT prophylaxis with shielding of the THA components. METHODS AND MATERIALS: This is a retrospective analysis of THA patients undergoing RT prophylaxis of HO at Brigham and Women's Hospital between June 1994 and February 2004. Univariate and multivariate logistic regressions were used to assess the relationships of all variables to failure of RT prophylaxis. RESULTS: A total of 137 patients were identified and 84 were eligible for analysis (61%). The median RT dose was 750 cGy in one fraction, and the median follow-up was 24 months. Eight of 40 unshielded patients (20%) developed any progression of HO compared with 21 of 44 shielded patients (48%) (p = 0.009). Brooker Grade III-IV HO developed in 5% of unshielded and 18% of shielded patients (p = 0.08). Multivariate analysis revealed shielding (p = 0.02) and THA for prosthesis infection (p = 0.03) to be significant predictors of RT failure, with a trend toward an increasing risk of HO progression with age (p = 0.07). There was no significant difference in the prosthesis failure rates between shielded and unshielded patients. CONCLUSIONS: A significantly increased risk of failure of RT prophylaxis for HO was noted in those receiving shielding of the hip prosthesis. Shielding did not appear to reduce the risk of prosthesis failure.

Early biomechanical changes in lower extremity vein grafts--distinct temporal phases of remodeling and wall stiffness.

BACKGROUND: The geometric and biomechanical changes that contribute to vein graft remodeling are not well established. We sought to measure patterns of adaptation in lower extremity vein grafts and assess their correlation with clinical outcomes. METHODS: We conducted a prospective, longitudinal study of patients undergoing infrainguinal reconstruction with autogenous conduit. In addition to standard duplex surveillance, lumen diameter (of a defined index segment of the conduit) and pulse wave velocity (PWV) were assessed by ultrasound imaging at surgery and at 1, 3, and 6 months postoperatively. Graft dimensions and wall stiffness were correlated with clinical outcomes. RESULTS: There were 92 patients and 96 limbs in this study. On average, vein graft lumen diameter increased during the first month of implantation from 0.37 +/- .01 cm to 0.45 +/- 0.02 cm (mean +/- SEM; P = .002), representing a relative change of +21.6% (median +/- 14%; range, -31 to +67%) during this period. Of the entire cohort, 72% of grafts demonstrated appreciable dilation of the index segment during the first month. Index segment lumen diameter did not change appreciably beyond 1 month, with the notable exception of arm vein conduits, which showed continued tendency to dilate. PWV increased during the first 6 months (17.2 +/- 1.2 m/s to 23.2 +/- 2.4 m/s; P = .008), reflecting a nearly 40% increase in conduit stiffness (2.0 +/- .6 Mdynes/cm to 3.3 +/- .8 Mdynes/cm, P = .01). The greatest relative increase (25%) in PWV occurred from months 1 to 3. Loss of primary patency occurred in 24 cases (19 revisions, 5 occlusions), with a mean reintervention time of 7.6 months. Grafts that demonstrated early positive remodeling (lumen dilatation) had a trend of increased primary patency (P = .08, log rank). Among the grafts that failed, a trend was noted toward greater wall stiffness at 1 month, 2.7 vs 1.5 Mdynes (P = .08). CONCLUSION: Vein graft remodeling appears to involve at least two distinct temporal phases. Outward remodeling of the lumen occurs early, and wall stiffness changes occur in a more delayed fashion. Early outward remodeling may be important for successful vein graft adaptation.

Selection and plan switching behavior.

A majority of employees can choose among health insurance plans of varying generosity. They may switch plans if prices, information, or their health status change. This paper analyzes switching behavior presumptively caused by changes in health status. We show that people who move to a less generous plan have lower medical spending prior to the switch than the average for the generous plan in which they started, while those who move to a more generous plan appear to anticipate higher spending, which they delay until after the switch. This transfer of costs from a less to a more generous plan increases the burden of adverse selection. Our data suggest that switching may be more important to the level of premiums than previously documented.

Does reimbursement influence chemotherapy treatment for cancer patients?

Before the Medicare Prescription Drug, Improvement, and Modernization Act (MMA) of 2003, Medicare reimbursed physicians for chemotherapy drugs at rates that greatly exceeded physicians' costs for those drugs. We examined the effect of physician reimbursement on chemotherapy treatment of Medicare beneficiaries older than age sixty-five with metastatic lung, breast, colorectal, or other gastrointestinal cancers between 1995 and 1998 (9,357 patients). A physician's decision to administer chemotherapy to metastatic cancer patients was not measurably affected by higher reimbursement. Providers who were more generously reimbursed, however, prescribed more-costly chemotherapy regimens to metastatic breast, colorectal, and lung cancer patients.

Early adaptation of human lower extremity vein grafts: wall stiffness changes accompany geometric remodeling.

OBJECTIVE: To quantitatively describe the temporal changes in elastic properties and wall dimensions in lower-extremity vein grafts after implantation. DESIGN OF STUDY: This is a prospective study of patients (N = 38) undergoing lower extremity bypass grafts (N = 41) with autologous veins. Pulse wave velocity (PWV), luminal diameter, and wall thickness measurements were obtained by duplex ultrasound scan intraoperatively and at 1, 3, and 6 months postoperatively for assessment of graft dimensions and wall stiffness. RESULTS: Lower extremity vein grafts showed an increase in PWV (from 16 +/- 1 to 21 +/- 3 cm/s; mean +/- SEM; P =.08), reflecting an increase in wall stiffness (from 1.2 +/- 0.2 to 2.5 +/- 0.7 x 10(6) dynes/cm; P =.02) and wall thickness (from 0.47 +/- 0.03 to 0.61 +/- 0.004 mm; P =.04) over the first 6 months after implantation. Changes in lumen diameter were positively correlated with changes in external graft diameter (P <.01) and negatively correlated with initial lumen diameter (P <.01) but not with changes in the wall thickness. CONCLUSIONS: These results suggest complex remodeling of vein grafts during the first several months after implantation, with increased wall thickness occurring independent of variable changes in lumen diameter. Simultaneously, a marked increase in wall stiffness over this interval suggests a likely role for collagen deposition.

Preoperative risk factors for carotid endarterectomy: defining the patient at high risk.

PURPOSE: The efficacy of carotid endarterectomy (CEA) for prevention of stroke has been demonstrated in randomized trials; however, the optimal approach in patients excluded from these trials or who have other significant comorbid conditions remains controversial, particularly with the advent of percutaneous interventions. We examined the influence of putative risk factors on outcome of CEA in a single-center experience. METHODS: A retrospective analysis of 1370 consecutive CEA performed from 1990 to 1999 was undertaken. Preoperative risk factors examined included age older than 80 years, congestive heart failure, chronic obstructive pulmonary disease, renal failure (serum creatinine concentration > 2.0 mg/dL), contralateral carotid artery occlusion, recurrent ipsilateral carotid artery stenosis, ipsilateral hemispheric symptoms within 6 weeks, and recent coronary bypass grafting (CABG). The Fisher exact test was used to identify baseline variables associated with perioperative (30 days) risk for stroke or death. Multivariate analysis with Poisson regression was used to study the effect of all univariate criteria in combination. RESULTS: In the overall cohort, there were 32 adverse events (2.3%), including 11 deaths (0.8%), 6 disabling strokes (0.4%), and 10 nondisabling strokes (0.7%). There was no significant difference in incidence of perioperative stroke or death between patients with one or more risk factors (n = 689) and those with no risk factors (low risk, n = 681). Thirty-day mortality was significantly greater in patients with two or more risk factors compared with patients with no risk factors (2.8% vs 0.3%; P =.04), but no significant difference was noted in perioperative stroke rate (2.3% vs 1.0%). Univariate analysis demonstrated that contralateral carotid occlusion (n = 75) was the only significant predictor of adverse outcome (5 events, 6.7%) among the variables tested; this was confirmed with multivariate analysis (relative risk, 4.3; 95% confidence interval, 1.2-12.3; P =.01). Five-year survival for patients with two or more risk factors was notably diminished compared with that for patients with no risk factors (38.7% +/- 5.9% vs 75.0% +/- 2.6%; P <.001). Contralateral occlusion was also associated with reduced 5-year survival (38 +/- 11% vs 67 +/- 2%; P <.004). CONCLUSION: CEA can be safely performed in patients deemed at high risk, including those aged 80 years or older and others with significant comorbid conditions, with combined stroke and mortality rates comparable to those found in randomized trials, ie, the Asymptomatic Carotid Atherosclerosis Study and the North American Symptomatic Carotid Endarterectomy Trial. Contralateral occlusion may be a predictor for moderately increased perioperative risk and for reduced long-term survival. Caution may be warranted in asymptomatic patients with multiple risk factors, in whom presumed long-term benefit of CEA may be compromised by markedly reduced 5-year survival.