Reporting and analysis of sex in vascular surgery research.

OBJECTIVE: To examine sex in human vascular surgery research by quantifying the inclusion and analysis of sex-based data in high-impact vascular surgery journals. METHODS: A bibliographic review of original articles published in the European Journal of Vascular and Endovascular Surgery, Journal of Vascular Surgery, JVS: Venous and Lymphatic Disorders, Journal of Endovascular Therapy, and Annals of Vascular Surgery from January 1, 2018, to December 31, 2020, and from January 1, 2023, to December 31, 2023, was conducted. Abstracted data included sex-based data analysis, inclusion of sex as a variable in multivariable analysis, inclusion of sex as an independent variable, and a discussion of sex-based results. RESULTS: Of the 3762 articles that included human, animal, or cell subjects, 249 (6.6%) did not state sex. Of those 249 articles, 183 included human subjects, 55 included animal subjects, and 11 used cell lines as the subjects. These were removed from analysis as well as the remaining 68 articles with animal subjects. In addition, 23 researched a sex-specific pathology and were removed from analysis. Of the remaining 3422 articles included in our study, 42.3% analyzed sex, 46.9% included sex in multivariable analysis, 4.8% included sex as an independent variable, and 26.6% included a discussion of sex. There were no significant differences in all four sex variables between 2018, 2019, and 2020. Between 2018-2020 and 2023, there were significant increases in all four sex variables. Multicenter studies had significantly higher rates of independent analysis of sex over single-center studies (7.4% vs 3.3%, P < .001). There was no significant difference in independent analysis of sex between U.S.-based and non-U.S.-based studies. Only 191 articles (5.6%) had 90% or greater matching of men and women in their study. CONCLUSIONS: Equitable inclusion and analysis of sex is rare in vascular surgery research. Less than 5% of articles included an independent analysis of data by sex, and few studies included males and females equally. Clinical research is the basis for evidence-based medicine; therefore, it is important to strive for equitable inclusion, analysis, and reporting of data to foster generalizability of clinical research to men and women.

Burnout is not associated with trainee performance on the Vascular Surgery In-Training Exam.

OBJECTIVE: The Vascular Surgery In-Training Examination (VSITE) is a yearly exam evaluating vascular trainees' knowledge base. Although multiple studies have evaluated variables associated with exam outcomes, few have incorporated training program-specific metrics. The purpose of this study is to evaluate the impact of the learning environment and burnout on VSITE performance. METHODS: Data was collected from a confidential, voluntary survey administered after the 2020 to 2022 VSITE as part of the SECOND Trial. VSITE scores were calculated as percent correct then standardized per the American Board of Surgery. Generalized estimating equations with robust standard errors and an independent correlation structure were used to evaluate trainee and program factors associated with exam outcomes. Analyses were further stratified by integrated and independent training paradigms. RESULTS: A total of 1385 trainee responses with burnout data were collected over 3 years (408 in 2020, 459 in 2021, 498 in 2022). On average, 46% of responses reported at least weekly burnout symptoms. On unadjusted analysis, burnout symptoms correlated with a 14 point drop in VSITE score (95% confidence interval [CI], -24 to -4; P = .006). However, burnout was no longer significant after adjusted analysis. Instead, higher postgraduate year level, being in a relationship, identifying as male gender with or without kids, identifying as non-Hispanic white, larger programs, and having a sense of belonging within a program were associated with higher VSITE scores. CONCLUSIONS: Despite high rates of burnout, trainees generally demonstrate resilience in gaining the medical knowledge necessary to pass the VSITE. Performance on standardized exams is associated with trainee and program characteristics, including availability of support systems and program belongingness.

Urological Outcome of the Xiao Procedure in Children with Myelomeningocele and Lipomyelomeningocele Undergoing Spinal Cord Detethering.

PURPOSE: Although previous studies have revealed high success rates (70% to 85%) after an intradural somatic-to-autonomic nerve transfer procedure in children with spinal dysraphism, no study has had a control group or blinded observers. We report a rigorously designed study to investigate the effectiveness of the Xiao procedure. MATERIALS AND METHODS: Children with neurogenic bladder dysfunction related to myelomeningocele or lipomyelomeningocele who required spinal cord detethering were randomized to 2 groups at surgery, with half undergoing only spinal cord detethering and half undergoing the Xiao procedure in addition to detethering. Double-blind evaluations were performed at regular intervals during the 3-year followup. RESULTS: A total of 10 patients underwent spinal cord detethering only and 10 underwent detethering plus the Xiao procedure. The Xiao procedure did not result in voluntary voiding or continence in any patient, but patients undergoing spinal cord detethering plus the Xiao procedure were more likely to have greater improvements in total bladder capacity, bladder overactivity and overall quality of life than those who underwent detethering only. By the end of the study no participant or evaluator was able to accurately predict to which group the patients had been assigned. CONCLUSIONS: The results of this randomized controlled trial are in agreement with recently published similarly poor results of the Xiao procedure in patients with spinal cord injury. Improvements in bladder parameters observed in this study may be related to sacral nerve root section, a necessary portion of the Xiao procedure, instead of reinnervation. Confirmatory animal studies are recommended before further clinical trials of the Xiao procedure are performed in humans.

Lack of efficacy of an intradural somatic-to-autonomic nerve anastomosis (Xiao procedure) for bladder control in children with myelomeningocele and lipomyelomeningocele: results of a prospective, randomized, double-blind study.

OBJECTIVE Xiao et al. and other investigators have studied an intradural somatic-to-autonomic (e.g., L-5 to S3-4) nerve transfer as a method to create a reflex arc to allow bladder emptying in response to cutaneous stimulation (the Xiao procedure). In previous clinical studies of patients with spinal dysraphism who underwent the Xiao procedure, high success rates (70%-85%) were reported for the establishment of a "skin-CNS-bladder" reflex arc that allows spontaneous, controlled voiding in children with neurogenic bladder dysfunction. However, many of these studies did not use blinded observers, did not have control groups, and/or featured only limited follow-up durations. METHODS A randomized, prospective, double-blind trial was initiated in March 2009, enrolling children with myelomeningocele (MM), lipomyelomeningocele (LMM), and neurogenic bladder dysfunction who were scheduled for spinal cord detethering (DT) for the usual indications. At the time of DT, patients were randomized between 2 arms of the study: half of the patients underwent a standard spinal cord DT procedure alone (DT group) and half underwent DT as well as the Xiao procedure (DT+X group). Patients, families, and study investigators, all of whom were blinded to the surgical details, analyzed the patients' strength, sensory function, mobility, voiding, and urodynamic bladder function before surgery and at regular intervals during the 3-year follow-up. RESULTS Twenty patients were enrolled in the study: 10 underwent only DT and the other 10 underwent DT+X. The addition of the Xiao procedure to spinal cord DT resulted in longer operative times (p = 0.024) and a greater chance of wound infection (p = 0.03). Patients in both treatment arms could intermittently void or dribble small amounts of urine (< 20% total bladder capacity) in response to scratching in dermatomes T-9 through S-2 using a standardized protocol, but the voiding was not reproducible and the volume voided was not clinically useful in any patient. Voiding in response to scratching was not more frequent in patients who underwent DT+X compared with those who underwent only DT. Bladder contractions in response to scratching occurred in both treatment arms at various intervals after surgery, but they were not more reproducible or more frequent in the patients who underwent the Xiao procedure than in the patients who did not. No patient in either treatment arm was continent of urine before, during, or after the study. CONCLUSIONS Patients with MM and LMM who underwent the Xiao procedure during spinal cord DT were no more likely to be able to void, to control their urination, to achieve continence, or to have a demonstrable urodynamic bladder contraction in response to cutaneous stimulation than patients who underwent only spinal cord DT. This study, in the context of disappointing results reported in other recent studies of the Xiao procedure, raises doubts about the clinical applicability of this procedure in humans until further basic science research is performed.

Phenylalanine hydroxylase gene in psychiatric patients: screening and functional assay of mutations.

BACKGROUND: Reports relating phenylalanine kinetics and metabolism to psychiatric disorders led us to undertake the comprehensive screening of the phenylalanine hydroxylase (PAH) coding region and functional testing of discovered mutations in a sample of psychiatric patients and healthy control subjects. METHODS: Genomic DNA from psychiatric patients and control subjects was assayed for sequence variants in all PAH coding regions and splice junctions. In vivo functional analysis of mutations was conducted by assessing the kinetics and conversion to tyrosine of a standardized phenylalanine dose and by measuring fasting pterin levels. RESULTS: A known missense mutation was observed in a schizoaffective subject, and a novel missense mutation was discovered in four subjects with schizophrenia and one normal subject. The schizoaffective patient heterozygous for the known A403V mutation showed the lowest rate of phenylalanine kinetics and lowest conversion to tyrosine in the patient sample. The four schizophrenic patients heterozygous for the novel K274E mutation showed significantly decreased phenylalanine kinetics, reduced conversion to tyrosine, and increased synthesis of the PAH cofactor tetrahydrobiopterin compared with schizophrenic subjects without the mutation. CONCLUSIONS: The study findings suggest that larger scale studies are warranted to test the relationship of the PAH genotype with a psychiatric phenotype.

Attempted bladder reinnervation and creation of a scratch reflex for bladder emptying through a somatic-to-autonomic intradural anastomosis.

An intradural somatic-to-autonomic anastomosis, or Xiao procedure, has been described to create a "skin-CNS-bladder" reflex that improves bladder and bowel function in patients with neurogenic bladder and bowel dysfunction. The authors present their experience with a 10-year-old boy with chronic neurogenic bladder and bowel dysfunction related to spinal cord injury who underwent the Xiao procedure. After undergoing a left L-5 ventral root to left S2-3 intradural anastomosis, the patient reported that his bladder and bowel dysfunction improved between 6 and 12 months. Two years after the procedure, however, he reported that there was no change in his bladder or bowel dysfunction as compared with his condition prior to the procedure. Frequent, systematic multidisciplinary evaluations produced conflicting data. Electrophysiological and histological evaluation of the previously performed anastomosis during surgical reexploration 3 years after the Xiao procedure revealed that the anastomosis was in anatomical continuity but neuroma formation had prevented reinnervation. Nerve action potentials were not demonstrable across the anastomosis, and stimulation of the nerve above and below the anastomosis created no bladder or perineal contractions. This is the first clinical report on the outcome of the Xiao procedure in a child with spinal cord injury outside of China. It is impossible to draw broad conclusions about the efficacy of the procedure based on a single patient with no demonstrable benefit. However, future studies should carefully interpret transient improvements in bladder function, urodynamic findings, and the patient's ability to void in response to scratching after the Xiao procedure. The authors' experience with the featured patient, in whom reinnervation could not be demonstrated, suggests that such changes could be related to factors other than the establishment of a skin-CNS-bladder reflex as a result of a somatic-to-autonomic anastomosis.

Analysis of plasma biopterin levels in psychiatric disorders suggests a common BH4 deficit in schizophrenia and schizoaffective disorder.

Tetrahydrobiopterin (BH4) is an essential cofactor for amine neurotransmitter synthesis. BH4 also stimulates and modulates the glutamatergic system, and regulates the synthesis of nitric oxide by nitric oxide synthases. A connection between BH4 deficiencies and psychiatric disorders has been previously reported; major depression and obsessive-compulsive disorder have been found in subjects with a BH4 deficiency disorder and more recently we have observed a robust plasma deficit of biopterin (a measure of BH4), in a large group of schizophrenic patients compared to control subjects. To extend our previous finding in schizophrenia, we analyzed plasma biopterin levels from patients with schizoaffective and bipolar disorders. A significant difference in biopterin was seen among the diagnostic groups (P < 0.0001). Post hoc analyses indicated significant biopterin deficits relative to the normal control group for the schizoaffective group, who had biopterin levels comparable to the schizophrenic group. Bipolar disorder subjects had plasma biopterin levels that were higher that the schizoaffective disorder group and significantly higher than the schizophrenic group. The demonstrated significant biopterin deficit in both schizophrenia and schizoaffective disorder, may suggest an etiological role of a BH4 deficit in these two disorders, via dysregulation of neurotransmitter systems.

Evidence for a tetrahydrobiopterin deficit in schizophrenia.

Tetrahydrobiopterin (BH(4)) is a vital cofactor maintaining availability of the amine neurotransmitters [dopamine (DA), noradrenaline (NA), and serotonin (5-HT)], regulating the synthesis of nitric oxide (NO) by nitric oxide synthase (NOS), and stimulating and modulating the glutamatergic system (directly and indirectly). These BH(4) properties and their potential relevance to schizophrenia led us to investigate the hypothesis of a study group (healthy controls, n=37; schizophrenics, n=154) effect on fasting plasma total biopterin levels (a measure of BH(4)). Study analysis showed a highly significant deficit of total biopterins for the schizophrenic sample after partialling out the effects of potential confounds of gender, age, ethnicity, neuroleptic use history and dose of current use, 24-hour dietary phenylalanine/protein ratio (a dietary variable relevant to BH(4) synthesis), and plasma phenylalanine (which stimulates BH(4) synthesis). A mean decrement of 34% in plasma total biopterins for schizophrenics from control values supports clinical relevance for the finding. In a subsample (21 controls and 23 schizophrenics), sequence analysis was done of the GTP cyclohydrolase I feedback regulatory gene and no mutations were found in the coding region of the gene. A deficiency of BH(4) could lead to hypofunction of the systems of DA, NA, 5-HT, NOS/NO, and glutamate, all of which have been independently implicated in schizophrenia psychopathology. Further, evidence has been accumulating which implicates the critical interdependence of these neurotransmitter systems in schizophrenia; this concept, along with the present study finding of a biopterin deficit, suggests that further study of the BH(4) system in schizophrenia is warranted and desirable.