Endoscopic Versus Open Repair for Craniosynostosis in Infants Using Propensity Score Matching to Compare Outcomes: A Multicenter Study from the Pediatric Craniofacial Collaborative Group

BACKGROUND

The North American Pediatric Craniofacial Collaborative Group (PCCG) established the Pediatric Craniofacial Surgery Perioperative Registry to evaluate outcomes in infants and children undergoing craniosynostosis repair. The goal of this multicenter study was to utilize this registry to assess differences in blood utilization, intensive care unit (ICU) utilization, duration of hospitalization, and perioperative complications between endoscopic-assisted (ESC) and open repair in infants with craniosynostosis. We hypothesized that advantages of ESC from single-center studies would be validated based on combined data from a large multicenter registry.

METHODS

Thirty-one institutions contributed data from June 2012 to September 2015. We analyzed 1382 infants younger than 12 months undergoing open (anterior and/or posterior cranial vault reconstruction, modified-Pi procedure, or strip craniectomy) or endoscopic craniectomy. The primary outcomes included transfusion data, ICU utilization, hospital length of stay, and perioperative complications; secondary outcomes included anesthesia and surgical duration. Comparison of unmatched groups (ESC: N = 311, open repair: N = 1071) and propensity score 2:1 matched groups (ESC: N = 311, open repair: N = 622) were performed by conditional logistic regression analysis.

RESULTS

Imbalances in baseline age and weight are inherent due to surgical selection criteria for ESC. Quality of propensity score matching in balancing age and weight between ESC and open groups was assessed by quintiles of the propensity scores. Analysis of matched groups confirmed significantly reduced utilization of blood (26% vs 81%, P < .001) and coagulation (3% vs 16%, P < .001) products in the ESC group compared to the open group. Median blood donor exposure (0 vs 1), anesthesia (168 vs 248 minutes) and surgical duration (70 vs 130 minutes), days in ICU (0 vs 2), and hospital length of stay (2 vs 4) were all significantly lower in the ESC group (all P < .001). Median volume of red blood cell administered was significantly lower in ESC (19.6 vs 26.9 mL/kg, P = .035), with a difference of approximately 7 mL/kg less for the ESC (95% confidence interval for the difference, 3-12 mL/kg), whereas the median volume of coagulation products was not significantly different between the 2 groups (21.2 vs 24.6 mL/kg, P = .73). Incidence of complications including hypotension requiring treatment with vasoactive agents (3% vs 4%), venous air embolism (1%), and hypothermia, defined as <35°C (22% vs 26%), was similar between the 2 groups, whereas postoperative intubation was significantly higher in the open group (2% vs 10%, P < .001).

CONCLUSIONS

This multicenter study of ESC versus open craniosynostosis repair represents the largest comparison to date. It demonstrates striking advantages of ESC for young infants that may result in improved clinical outcomes, as well as increased safety.

How Should Refusal of Tracheostomy as Part of an Adolescent's Perioperative Planned Intubation Be Regarded?

Here we present a case of a patient in terminal respiratory failure refusing to consent to emergent tracheostomy in the setting of an anticipated difficult intubation. We examine ethical concerns that arise from deviations from the standard of care in the operative setting and the anesthesiologist's sense of culpability. Finally, we will review the ethical arguments and guidelines that support anesthesiologists' participation in palliative operative procedures when limitations on resuscitation are in place.

White-crowned sparrow males show immediate flexibility in song amplitude but not in song minimum frequency in response to changes in noise levels in the field

The soundscape acts as a selective agent on organisms that use acoustic signals to communicate. A number of studies document variation in structure, amplitude, or timing of signal production in correspondence with environmental noise levels thus supporting the hypothesis that organisms are changing their signaling behaviors to avoid masking. The time scale at which organisms respond is of particular interest. Signal structure may evolve across generations through processes such as cultural or genetic transmission. Individuals may also change their behavior during development (ontogenetic change) or in real time (i.e., immediate flexibility). These are not mutually exclusive mechanisms, and all must be investigated to understand how organisms respond to selection pressures from the soundscape. Previous work on white-crowned sparrows (Zonotrichia leucophrys) found that males holding territories in louder areas tend to sing higher frequency songs and that both noise levels and song frequency have increased over time (30 years) in urban areas. These previous findings suggest that songs are changing across generations; however, it is not known if this species also exhibits immediate flexibility. Here, we conducted an exploratory, observational study to ask whether males change the minimum frequency of their song in response to immediate changes in noise levels. We also ask whether males sing louder, as increased minimum frequency may be physiologically linked to producing sound at higher amplitudes, in response to immediate changes in environmental noise. We found that territorial males adjust song amplitude but not minimum frequency in response to changes in environmental noise levels. Our results suggest that males do not show immediate flexibility in song minimum frequency, although experimental manipulations are needed to test this hypothesis further. Our work highlights the need to investigate multiple mechanisms of adaptive response to soundscapes.

The catalytic function of cytochrome P450 is entwined with its membrane-bound nature

Cytochrome P450, a family of monooxygenase enzymes, is organized as a catalytic metabolon, which requires enzymatic partners as well as environmental factors that tune its complex dynamic. P450 and its reducing counterparts—cytochrome P450-reductase and cytochrome b ₅—are membrane-bound proteins located in the cytosolic side of the endoplasmic reticulum. They are believed to dynamically associate to form functional complexes. Increasing experimental evidence signifies the role(s) played by both protein-protein and protein-lipid interactions in P450 catalytic function and efficiency. However, the biophysical challenges posed by their membrane-bound nature have severely limited high-resolution understanding of the molecular interfaces of these interactions. In this article, we provide an overview of the current knowledge on cytochrome P450, highlighting the environmental factors that are entwined with its metabolic function. Recent advances in structural biophysics are also discussed, setting up the bases for a new paradigm in the study of this important class of membrane-bound enzymes.

Safety of antifibrinolytics in cranial vault reconstructive surgery: a report from the pediatric craniofacial collaborative group

BACKGROUND

Antifibrinolytic therapy significantly decreases blood loss and transfusion in pediatric cranial vault reconstructive surgery; however, concern regarding the side effects profile limits clinical use.

AIMS

The aim was to utilize the Pediatric Craniofacial Surgery Perioperative Registry database to identify the safety profile of antifibrinolytic therapy for cranial vault reconstructive surgery by reporting the incidence of adverse events as they relate to exposure to tranexamic acid and aminocaproic acid compared to no exposure to antifibrinolytics.

METHODS

The database was queried for cases of open cranial vault reconstructive surgery. Less invasive procedures such as neuro-endoscopic and spring-mediated cranioplasties were excluded. The outcomes evaluated included any perioperative neurological adverse event including seizures or seizure-like movements and thromboembolic events.

RESULTS

Thirty-one institutions reported a total of 1638 cases from 2010 to 2015. Total antifibrinolytic administration accounted for 59.5% (tranexamic acid, 36.1% and aminocaproic acid, 23.4%), with 40.5% not receiving any antifibrinolytic. The overall incidence of postoperative seizures or seizure-like movements was 0.6%. No significant difference was detected in the incidence of postoperative seizures between patients receiving tranexamic acid and those receiving aminocaproic acid [the odds ratio for seizures being 0.34 (95% confidence interval: 0.07-1.85) controlling for American Society of Anesthesia (ASA) physical class] nor in patients receiving antifibrinolytics compared to those not administered antifibrinolytics (the odds ratio for seizures being 1.02 (confidence interval 0.29-3.63) controlling for ASA physical class). One complicated patient in the antifibrinolytic group with a femoral venous catheter had a postoperative deep venous thrombosis.

CONCLUSIONS

This is the first report of an incidence of postoperative seizures of 0.6% in pediatric cranial vault reconstructive surgery. There was no significant difference in postoperative seizures or seizure-like events in those patients who received the tranexamic acid or aminocaproic acid vs those that did not. This report provides evidence of the safety profile of antifibrinolytic in children having noncardiac major surgery. Caution should prevail however in using antifibrinolytic in high-risk patients. Antifibrinolytic dosage regimes should be based on pharmacokinetic data avoiding high doses.

Patterns of Song across Natural and Anthropogenic Soundscapes Suggest That White-Crowned Sparrows Minimize Acoustic Masking and Maximize Signal Content

Soundscapes pose both evolutionarily recent and long-standing sources of selection on acoustic communication. We currently know more about the impact of evolutionarily recent human-generated noise on communication than we do about how natural sounds such as pounding surf have shaped communication signals over evolutionary time. Based on signal detection theory, we hypothesized that acoustic phenotypes will vary with both anthropogenic and natural background noise levels and that similar mechanisms of cultural evolution and/or behavioral flexibility may underlie this variation. We studied song characteristics of white-crowned sparrows (Zonotrichia leucophrys nuttalli) across a noise gradient that includes both anthropogenic and natural sources of noise in San Francisco and Marin counties, California, USA. Both anthropogenic and natural soundscapes contain high amplitude low frequency noise (traffic or surf, respectively), so we predicted that birds would produce songs with higher minimum frequencies in areas with higher amplitude background noise to avoid auditory masking. We also anticipated that song minimum frequencies would be higher than the projected lower frequency limit of hearing based on site-specific masking profiles. Background noise was a strong predictor of song minimum frequency, both within a local noise gradient of three urban sites with the same song dialect and cultural evolutionary history, and across the regional noise gradient, which encompasses 11 urban and rural sites, several dialects, and several anthropogenic and natural sources of noise. Among rural sites alone, background noise tended to predict song minimum frequency, indicating that urban sites were not solely responsible for driving the regional pattern. These findings support the hypothesis that songs vary with local and regional soundscapes regardless of the source of noise. Song minimum frequency from five core study sites was also higher than the lower frequency limit of hearing at each site, further supporting the hypothesis that songs vary to transmit through noise in local soundscapes. Minimum frequencies leveled off at noisier sites, suggesting that minimum frequencies are constrained to an upper limit, possibly to retain the information content of wider bandwidths. We found evidence that site noise was a better predictor of song minimum frequency than territory noise in both anthropogenic and natural soundscapes, suggesting that cultural evolution rather than immediate behavioral flexibility is responsible for local song variation. Taken together, these results indicate that soundscapes shape song phenotype across both evolutionarily recent and long-standing soundscapes.

Mesoporous silica-supported lipid bilayers (protocells) for DNA cargo delivery to the spinal cord

Amorphous mesoporous silica nanoparticles ('protocells') that support surface lipid bilayers recently characterized in vitro as carrier constructs for small drug and DNA delivery are reported here as highly biocompatible both in vitro and in vivo, involving the brain and spinal cord following spinal delivery into the lumbosacral subarachnoid space (intrathecal; i.t.). Specifically, positively charged, 1, 2-Dioleoyl-3-Trimethylammonium-Propane (DOTAP)-cholesterol (DOTAP:Chol) liposome-formulated protocells revealed stable in vitro cargo release kinetics and cellular interleukin-10 (IL-10) transgene transfection. Recent approaches using synthetic non-viral vector platforms to deliver the pain-suppressive therapeutic transgene, IL-10, to the spinal subarachnoid space have yielded promising results in animal models of peripheral neuropathy, a condition involving aberrant neuronal communication within sensory pathways in the nervous system. Non-viral drug and gene delivery protocell platforms offer potential flexibility because cargo release-rates can be pH-dependent. We report here that i.t. delivery of protocells, with modified chemistry supporting a surface coating of DOTAP:Chol liposomes and containing the IL-10 transgene, results in functional suppression of pain-related behavior in rats for extended periods. This study is the first demonstration that protocell vectors offer amenable and enduring in vivo biological characteristics that can be applied to spinal gene delivery.

Low prevalence of psychoses among the Hutterites, an isolated religious community

OBJECTIVE

The authors estimated the prevalence of psychoses among the Hutterites in Manitoba, Canada, who lived in 102 communal farms or colonies. The study stemmed from an earlier epidemiological survey of North American Hutterite colonies (1950-1953), in which a low prevalence of psychoses was documented.

METHOD

Psychiatrically ill individuals identified during the previous survey were rediagnosed with DSM-IV criteria. A current provincial health insurance claims database was queried anonymously for the period June 1992-May 1997, and the prevalence rate of disease among Hutterites, identified by distinctive surnames and unique postal addresses, was compared with the rate in the entire population of the province of Manitoba and in a comparison group of persons with Hutterite surnames but with addresses outside the Hutterite colonies.

RESULTS

The annual prevalence of schizophrenia among the communal Hutterites, estimated from the database search by using ICD-9 criteria, was consistent with the prevalence found in the prior epidemiological survey (annual mean of 1.2/1,000 population, compared with 1.3/1,000 in the prior survey). The database search yielded a significantly lower prevalence for schizophrenia and other functional psychoses among communal Hutterites as well as among the comparison group, compared to the total Manitoba population. There was also lower prevalence for affective psychoses and adjustment reaction disorders among the communal Hutterites, compared to the total Manitoba population. Rates for neurotic disorders were elevated both among the communal Hutterites and the comparison group.

CONCLUSIONS

The prevalence of specific psychoses was reduced among the Hutterites, although neurotic disorders were more prevalent. These findings suggest some specificity, although possible artifacts such as ascertainment bias must be considered. Further research is needed to examine genetic and environmental factors that may contribute to reduced prevalence of specific psychoses among the Hutterites.

High-affinity interleukin-2 receptors on blood lymphocytes are decreased during active rheumatoid arthritis

The expression of receptors for interleukin-2 (IL-2R) was examined in patients with active or inactive rheumatoid arthritis (RA) and in control subjects. Unstimulated blood lymphocytes from patients with active RA had increased levels of total IL-2R, as measured by Tac-positive cells, compared with the levels found in the other 2 groups. Mitogen-stimulated cells from patients with active RA expressed less IL-2R per cell, but the most striking feature was the failure to express high-affinity IL-2R. These changes could reflect persistent antigenic stimulation and explain the defective cell-mediated immunity in RA patients.

Psychologic assessment of morbidly obese patients undergoing gastric bypass: a comparison of preoperative and postoperative adjustment

Thirty-three morbidly obese patients underwent gastric bypass operation after intensive medical and psychiatric evaluation. Five psychometric tests were administered before and after operation. The study patients were found to have less self-esteem and more depressive traits than a normal population. This did not change after operation despite weight loss. High levels of optimism were not associated with better weight loss. However, patients who understood before operation that the success of the operation depended upon changing their eating behavior lost more weight. After operation patients expressed satisfaction with life and a new freedom from constant hunger. There was a reported decrease in organic symptoms, an increase in social activities, an improvement in interpersonal relationships, and a social usefulness not experienced previously. In selected patients with no active psychiatric disease or psychologic instability, gastric bypass, coupled with consistent postoperative reinforcement, produces behavioral changes that can lead to permanent weight loss without concomitant psychologic deterioration.

Gastric bypass for morbid obesity: a medical--surgical assessment

With the operative modifications and dietary guidelines described in this report, death and complications from gastric bypass were minimal, and weight loss was marked. Ninety per cent of a group of 69 patients lost more than half of their excess weight within the first two years after operation. Stringent preselection of patients for operation was crucial to the success of the operation, and marked alterations of eating behavior was necessary to achieve the weight loss. Mild electrolyte deficiencies and hypovitaminosis occurred in up to one-fourth of the patients. While none of these abnormalities was harmful to the patients, and all were easily corrected, their occurrence demonstrates the importance of long-term follow-up after the operation. We conclude that gastric bypass, with a 50-60 cc pouch and a small (1-1.2 cm) gastrojejunostomy, remains the operation of choice for morbid obesity.

Jejunoileal bypass. Late metabolic sequelae and weight gain

Of 101 patients originally operated on, the status of 98 is known. Given the mortality and reanastomosis rates, the operation must be considered an absolute failure in 28 percent of the patients. Given the other complications that appear (or persist) late postoperatively, only 18 percent of the entire series of patients have had what can be considered a good result. We therefore conclude that intestinal bypass is not an appropriate operation for morbid obesity and that complete long-term follow-up is essential for all patients who undergo the operation, despite what might seem to be a smooth course in the 1st 2 years postoperatively.

Reanastomosis after jejunoileal bypass

One hundred and one patients underwent jejunoileal bypass after careful preoperative evaluation. These patients were re-evaluated after operation on a frequent basis, and 23% have required restoration of intestinal continuity (reanastomosis) by a mean postoperative time of 44 months. The most frequent reasons for reanastomosis were liver dysfunction (5% of the entire series), severe malnutrition or weakness (5%), and late electrolyte imbalance (4%). Two patients did not survive reanastomosis, both having liver failure. Of the patients who did survive, weight gain (approaching prebypass weight) and improvement in liver function tests, electrolyte balance, serum vitamin levels, and diarrhea have been the rule. Of the entire series of 101 patients who underwent bypass, 58% either had life-threatening complications, had to be reanastomosed, or died. These morbidity and mortality rates raise the important question of whether jejunoileal bypass is an appropriate procedure for the treatment of morbid obesity.