Identifying hemophilia B carriers: Utility of aPTT, factor IX levels and ratios of factor IX to other Vitamin K dependent factors.

INTRODUCTION: Diagnosing hemophilia B (HB) carrier status is important to manage bleeding in carriers and to prevent bleeding in potential offspring. Without a family history of hemophilia, diagnosing HB carrier status is challenging. Genetic testing is the gold-standard, however it is reserved for individuals with a high suspicion of carrier status. AIMS: To describe the distribution of activated partial thromboplastin time (aPTT) and factor IX coagulant (FIX:C) levels in HB carriers and assess the ratio of FIX:C to other Vitamin K dependent factors (FII:C, FVII:C, FX:C) as an indicator of HB carrier status. METHODS: In this retrospective, single-centre cohort study, subjects were included if they were obligate or genetically proven HB carriers. Distributions of aPTT and FIX:C were described and the relationship between FIX:C levels in carriers and severity of familial HB was analysed. Ratios of FIX:C to FII:C, FVII:C, FX:C were calculated. RESULTS: Seventy-two female HB carriers (median age: 34 years; IQR 24-43) were included. Median aPTT and FIX:C levels were 33.0 s [IQR 30.0-37.0] and 57 IU/dL [IQR 43-74]. Fifteen carriers (21%) had mild HB (FIX:C levels of 10-40 IU/dL). FIX:C levels trended higher in carriers of mild HB versus carriers of moderate/severe HB. In six carriers, the median ratio of FIX:C to other Vitamin K dependent factors was 0.44, with 92% of ratios being ≤ 0.75. CONCLUSION: aPTT and FIX:C levels were unreliable in diagnosing HB carrier status. A low ratio of FIX:C to other Vitamin K dependent factors may be a useful marker of HB carrier status.

Unravelling the effect of blood group on FVIII:C levels and response to DDAVP in 20 males with a single genotype (Twillingate Variant) causing Haemophilia A.

INTRODUCTION: The genetic variant responsible for haemophilia A (HA) significantly impacts endogenous coagulant factor VIII (FVIII:C) level, thus impacting DDAVP responsiveness. Blood group (BG) also impacts FVIII:C levels, but this is difficult to evaluate in a genetically heterogeneous population. Canada has a large cohort of mild-moderate HA due to a single point variant: c.6104T>C, p.Val2035Ala-the Twillingate variant. AIM: To evaluate the impact of BG on endogenous FVIII:C levels and DDAVP responsiveness in a single genotype of mild-moderate HA. METHODS: This was a retrospective, single-centre study. BG and FVIII:C levels were obtained for males with the Twillingate variant. One-hour absolute and fold increases in FVIII:C post-DDAVP were calculated. T-tests and Mann-Whitney U tests were used to compare FVIII:C levels and DDAVP challenge variables between individuals according to BGs (O vs. non-O). RESULTS: Twenty males were included. There were significant differences between BGs (O vs. non-O) in their lowest FVIII:C level at age <12 years (medians: 0.05 vs. 0.08 IU/mL; P = .05). Fifteen subjects underwent DDAVP challenges. Mean 1-h FVIII:C were 0.29 (O BG) versus 0.41 IU/mL (non-O BG); P = .04. There were no significant differences between BGs (O vs. non-O) in mean absolute FVIII:C increase (0.20 vs. 0.27 IU/mL; P = .10) and FVIII:C fold increase (3.3-fold vs. 3.8-fold; P = .51). CONCLUSION: In HA subjects with an identical genotype, BG significantly impacts baseline FVIII:C levels and FVIII:C levels post-DDAVP, but does not impact absolute and fold increases in FVIII:C with DDAVP.

The role of minimally invasive gynecologic surgeons in the era of subspecialties: when to refer and consult.

PURPOSE OF REVIEW: Minimally invasive gynecologic surgery (MIGS) is a subspecialty focus of obstetrics and gynecology with focused expertise on complex benign gynecologic disorders. To date, no formal recommendations have been made in defining a referral system for MIGS. This article reviews the evidence regarding common disorders and procedures and their outcomes, and posits a basis for MIGS referral. RECENT FINDINGS: In instances where intraoperative and perioperative features may pose clinical challenges to the surgeon and ultimately the patient, the literature suggests the following scenarios may have adverse outcomes, and therefore, benefit from the skills of MIGS subspecialists: fibroids - at least five myomas, myoma size at least 9 cm, and suspected myoma weight at least 500 g; endometriosis - presence of endometrioma(s), suspected stage III/IV endometriosis, and requirement for advanced adjunct procedures; hysterectomy - uteri at least 250 g or 12 weeks estimated size, at least three prior laparotomies, obesity, and complex surgical history with suspected adhesive disease. SUMMARY: A referral system for MIGS subspecialists has proven benefits for both the gynecologic surgical community as well as the patients and their outcomes. This article provides evidence for collaboration with MIGS especially as it relates to leiomyomatous uteri, endometriosis, and complex hysterectomies.

Renal Hilum Injury with Veress Needle.

Introduction: Since the advent of laparoscopy, the ideal first-port entry technique has not yet been determined. Use of the Veress needle at Palmer's point, although safe in practice under skilled physicians, is not without risk of complications. Case Description: A female patient with prior abdominal surgeries underwent a laparoscopic surgery for a nonmalignant indication. Intraoperative complications included hemodynamic instability and gross hematuria. The patient was ultimately stabilized, and imaging after the case revealed a hematoma formation around the left kidney with evidence of renal hilar injury. Discussion: The laparoscopic surgeon must be aware that blind Veress needle entry has inherent risk for injury of retroperitoneal structures including the renal system. Particularly if hemodynamic instability is noted after abdominal entry at any site, physicians should have a low threshold for investigation, including by laparotomy if necessary.

Femtosecond x-ray diffraction reveals a liquid-liquid phase transition in phase-change materials.

In phase-change memory devices, a material is cycled between glassy and crystalline states. The highly temperature-dependent kinetics of its crystallization process enables application in memory technology, but the transition has not been resolved on an atomic scale. Using femtosecond x-ray diffraction and ab initio computer simulations, we determined the time-dependent pair-correlation function of phase-change materials throughout the melt-quenching and crystallization process. We found a liquid-liquid phase transition in the phase-change materials Ag4In3Sb67Te26 and Ge15Sb85 at 660 and 610 kelvin, respectively. The transition is predominantly caused by the onset of Peierls distortions, the amplitude of which correlates with an increase of the apparent activation energy of diffusivity. This reveals a relationship between atomic structure and kinetics, enabling a systematic optimization of the memory-switching kinetics.

PROFILE OF PATIENTS WITH OSTEOPOROTIC FRACTURES AT A TERTIARY ORTHOPEDIC TRAUMA CENTER.

OBJECTIVE: To evaluate the profile of patients with osteoporotic fractures treated at a tertiary orthopedic hospital. METHODS: Using questionnaires, 70 patients with osteoporotic fractures (OF) were compared with 50 outpatients with multiple osteoarthritis (OA) followed through an outpatient clinic. RESULTS: The OF group was older (p <0.001), less heavy (p=0.003), had lower BMI (p=0.006), was more likely to be white (p=0.011), was less likely to be married (p=0.008), and had previous falls, previous fractures, old fractures (>1 year), falls in the last 12 months, fractures due to falls, and needed more assistance (p<0.05). They also had lower Lawton & Brody Instrumental Activities of Daily Living scores (p <0.05) and reported less lower limb disability, foot pathology, muscle weakness, hypothyroidism, and vitamin D intake than patients in the OA group. White race, previous falls, and previous fractures increase the risk of osteoporotic fractures by 10.5, 11.4, and 4.1 times, respectively. The chance of fracture dropped 29% for each one-unit increase in Lawton & Brody IADL score. Married participants had fewer fractures than participants with other marital status. CONCLUSION: Together, race, marital status, previous falls, foot pathologies, previous fractures, and IADL scores define the profile of patients with osteoporotic fractures. Level of Evidence III; Case control study.

OBJETIVO: Avaliar o perfil dos pacientes com fraturas osteoporóticas atendidos em hospital de atendimento terciário ortopédico. MÉTODOS: Setenta pacientes com fraturas osteoporóticas (FO) foram comparados a 50 pacientes com acompanhamento ambulatorial de osteoartrite (OA) por meio de questionários. RESULTADOS: O grupo FO apresentou média de idade maior (p < 0,001), menor peso (p = 0,003), menor IMC (p = 0,006), maior frequência de pacientes brancos (p = 0,011), menor frequência de casados (p = 0,008), mais quedas prévias, fraturas prévias, fratura antiga (> 1 ano), queda nos últimos 12 meses, fratura por causa da queda e necessitam de mais auxílio (p < 0,05); menor Lawton e Brody AIVD (Atividades instrumentais da vida diária, p < 0,05), reportando menos deficiência de membros inferiores, patologia nos pés, fraqueza muscular, hipotireoidismo e consumo de vitamina D do que pacientes do grupo OA. Raça branca, quedas e fraturas prévias aumentam o risco de fraturas osteoporóticas em 10,5, 11,4 e 4,1 vezes respectivamente. A chance de fratura foi reduzida em 29% a cada aumento de uma unidade no Lawton e Brody AIVD. Casados fraturam menos que outros estados civis. CONCLUSÃO: Conjuntamente, a raça, estado civil, quedas prévias, patologias nos pés, fraturas prévias e AIVD definem o perfil dos pacientes com fraturas osteoporóticas deste centro. Nível de Evidência III; Estudo de caso-controle.

Profile of patients with osteoporotic fractures at a tertiary orthopedic trauma center / Perfil de pacientes com fraturas osteoporóticas num centro terciário de trauma ortopédico

ABSTRACT Objective: To evaluate the profile of patients with osteoporotic fractures treated at a tertiary orthopedic hospital. Methods: Using questionnaires, 70 patients with osteoporotic fractures (OF) were compared with 50 outpatients with multiple osteoarthritis (OA) followed through an outpatient clinic. Results: The OF group was older (p <0.001), less heavy (p=0.003), had lower BMI (p=0.006), was more likely to be white (p=0.011), was less likely to be married (p=0.008), and had previous falls, previous fractures, old fractures (>1 year), falls in the last 12 months, fractures due to falls, and needed more assistance (p<0.05). They also had lower Lawton & Brody Instrumental Activities of Daily Living scores (p <0.05) and reported less lower limb disability, foot pathology, muscle weakness, hypothyroidism, and vitamin D intake than patients in the OA group. White race, previous falls, and previous fractures increase the risk of osteoporotic fractures by 10.5, 11.4, and 4.1 times, respectively. The chance of fracture dropped 29% for each one-unit increase in Lawton & Brody IADL score. Married participants had fewer fractures than participants with other marital status. Conclusion: Together, race, marital status, previous falls, foot pathologies, previous fractures, and IADL scores define the profile of patients with osteoporotic fractures. Level of Evidence III; Case control study.

RESUMO Objetivo: Avaliar o perfil dos pacientes com fraturas osteoporóticas atendidos em hospital de atendimento terciário ortopédico. Métodos: Setenta pacientes com fraturas osteoporóticas (FO) foram comparados a 50 pacientes com acompanhamento ambulatorial de osteoartrite (OA) por meio de questionários. Resultados: O grupo FO apresentou média de idade maior (p < 0,001), menor peso (p = 0,003), menor IMC (p = 0,006), maior frequência de pacientes brancos (p = 0,011), menor frequência de casados (p = 0,008), mais quedas prévias, fraturas prévias, fratura antiga (> 1 ano), queda nos últimos 12 meses, fratura por causa da queda e necessitam de mais auxílio (p < 0,05); menor Lawton e Brody AIVD (Atividades instrumentais da vida diária, p < 0,05), reportando menos deficiência de membros inferiores, patologia nos pés, fraqueza muscular, hipotireoidismo e consumo de vitamina D do que pacientes do grupo OA. Raça branca, quedas e fraturas prévias aumentam o risco de fraturas osteoporóticas em 10,5, 11,4 e 4,1 vezes respectivamente. A chance de fratura foi reduzida em 29% a cada aumento de uma unidade no Lawton e Brody AIVD. Casados fraturam menos que outros estados civis. Conclusão: Conjuntamente, a raça, estado civil, quedas prévias, patologias nos pés, fraturas prévias e AIVD definem o perfil dos pacientes com fraturas osteoporóticas deste centro. Nível de Evidência III; Estudo de caso-controle.

Minimally Invasive Hysterectomy for Uteri Greater Than One Kilogram.

BACKGROUND AND OBJECTIVES: To assess the feasibility and safety of minimally invasive hysterectomy for uteri >1 kg. METHODS: Clinical and surgical characteristics were collected for patients in an academic tertiary care hospital. Included were patients who underwent minimally invasive hysterectomy by 1 of 3 fellowship-trained gynecologists from January 1, 2009, to July 1, 2015 and subsequently had confirmed uterine weights of 1 kg or greater on pathology report. Both robotic and conventional laparoscopic procedures were included. RESULTS: During the study period, 95 patients underwent minimally invasive hysterectomy with confirmed uterine weight over 1 kg. Eighty-eight percent were performed with conventional laparoscopy and 12.6% with robot-assisted laparoscopy. The median weight (range) was 1326 g (range, 1000-4800). The median estimated blood loss was 200 mL (range, 50-2000), and median operating time was 191 minutes (range, 75-478). Five cases were converted to laparotomy (5.2%). Four cases were converted secondary to hemorrhage and one secondary to extensive adhesions. There were no conversions after 2011. Intraoperative transfusion was given in 6.3% of cases and postoperative transfusion in 6.3% of cases. However, after 2013, the rate of intraoperative transfusion decreased to 1.0% and postoperative transfusion to 2.1%. Of the 95 cases, there were no cases with malignancy. CONCLUSIONS: This provides the largest case series of hysterectomy over 1 kg completed by a minimally invasive approach. Our complication rate improved with experience and was comparable to other studies of minimally invasive hysterectomy for large uteri. When performed by experienced surgeons, minimally invasive hysterectomy for uteri >1 kg can be considered feasible and safe.

Comparison of cost and operative outcomes of robotic hysterectomy compared to laparoscopic hysterectomy across different uterine weights.

Operative cost and outcomes between robotic and laparoscopic hysterectomy across different uterine weights. Retrospective cohort study including patients undergoing robotic and laparoscopic hysterectomy for benign disease at an Academic university hospital. One hundred and ninety six hysterectomies were identified (101 robotic versus 95 laparoscopic). Demographic and surgical characteristics were statistically equivalent. Robotic group had a higher body mass index (±SD) (32.9 ± 6.5 versus 30.4 ± 7.1, p 0.012) and more frequent history of adnexal surgery (12.9 versus 4.2%, p 0.031). Laparoscopic group had a higher number of concurrent salpingectomy (81 versus 66.3%, p 0.02). Estimated blood loss did not differ between procedures. Compared to robotic hysterectomies, laparoscopic procedures added 47 min (CI: 31-63 min; p < 0.001) of operative time, costed $1648 more (CI: 500-2797; p = 0. 005) and had triple the odds of having an overnight admission (OR = 2.94 CI: 1.34-6.44; p = 0.007). After stratification of cases by uterine weight, the mean operative time difference between the two groups in uteri between 750 and 1000 g and in uteri >1000 g was 81.3 min (CI: 51.3-111.3, p < 0.0001) and 70 min (CI: 26-114, p < 0.005), respectively, in favor of the robotic group. Mean direct cost difference in uteri between 750 and 1000 g and uteri >1000 g was 1859$ (CI: 629-3090, p < 0.006) and 4509$ (CI: 377-8641, p < 0.004), respectively, also in favor of the robotic group. In expert hands, robotic hysterectomy for uteri weighing more than 750 g may be associated with shorter operative time and improved cost profile.

Picosecond Electric-Field-Induced Threshold Switching in Phase-Change Materials.

Many chalcogenide glasses undergo a breakdown in electronic resistance above a critical field strength. Known as threshold switching, this mechanism enables field-induced crystallization in emerging phase-change memory. Purely electronic as well as crystal nucleation assisted models have been employed to explain the electronic breakdown. Here, picosecond electric pulses are used to excite amorphous Ag_{4}In_{3}Sb_{67}Te_{26}. Field-dependent reversible changes in conductivity and pulse-driven crystallization are observed. The present results show that threshold switching can take place within the electric pulse on subpicosecond time scales-faster than crystals can nucleate. This supports purely electronic models of threshold switching and reveals potential applications as an ultrafast electronic switch.

Outcomes of tracheostomy following congenital heart surgery: a contemporary experience.

INTRODUCTION: Following congenital heart surgery, pediatric patients may experience persistent respiratory failure that requires tracheostomy placement. Currently, definitive knowledge of the optimal timing for tracheostomy placement in this patient population is lacking. METHODS: An 8-year retrospective review of 17 pediatric patients who underwent congenital heart surgery and subsequently required tracheostomy placement was performed. Patients were evaluated with regard to the timing of tracheostomy and mortality. RESULTS: The overall study mortality was 24%. The median duration of intubation prior to tracheostomy was 60 days (interquartile range: 19-90 days); there was no difference in the average time between intubation and tracheostomy for survivors compared with nonsurvivors (51 vs. 73 days, P = .37). No difference was observed in the overall duration of positive pressure ventilation when tracheostomy was performed within 30 days of intubation compared with greater than 30 days following intubation (481 vs. 451 days, P = .88). Overall, 18% of patients were successfully weaned from the ventilator after a median duration of positive pressure ventilation of 212 days. CONCLUSION: The timing of tracheostomy placement may be an important factor in clinical outcomes for pediatric patients with persistent dependence on mechanical ventilatory support following congenital heart surgery. A larger, multi-institution study may help further elucidate our observed clinical findings in this patient population.

Intermediate-term results of extracorporeal membrane oxygenation support following congenital heart surgery.

BACKGROUND: Although there are considerable data regarding in-hospital results of congenital heart surgery (CHS) patients requiring postoperative extracorporeal membrane oxygenation (ECMO) support, there is limited information on intermediate-term outcomes. METHODS: A single-institution retrospective review of 25 consecutive postoperative CHS patients who required ECMO and survived to hospital discharge between January 2003 and June 2008. Survival was estimated by the Kaplan-Meier method. RESULTS: At a median follow-up of 3.3 years (interquartile range: 1.2-5.9 years), there was one death which occurred at six months postsurgery. Kaplan-Meier-estimated survival at three years was 95% (95% confidence interval: 90%-100%). Indications for ECMO included extracorporeal cardiopulmonary resuscitation (48%), systemic hypoxia (4%), postoperative low-cardiac output syndrome (28%), and intraoperative failure to wean off cardiopulmonary bypass (20%). Following ECMO support, 65% of patients had unplanned cardiac reinterventions (three requiring operative interventions, six requiring percutaneous interventions, and four requiring both), and 47% of patients required unplanned hospitalizations. In all, 29% of patients developed neurological deficits and 12% of patients developed chronic respiratory failure. No patients developed renal failure. Overall, systemic ventricular (SV) function normalized in 83% of patients, whereas 17% of patients had persistent mild-to-moderate SV dysfunction. CONCLUSIONS: Intermediate-term patient survival of ECMO following CHS is encouraging. However, neurological impairment and unplanned cardiac reinterventions remain significant concerns. Further delineation of risk factors to improve patient outcomes is warranted.