Microvascular function in viable myocardium after chronic infarction does not influence fractional flow reserve measurements.

Fractional flow reserve (FFR) is an index of coronary stenosis severity. FFR is the ratio of hyperemic myocardial flow in the stenotic area to maximal flow in that same territory without stenosis and can be measured with a pressure wire. In patients with prior infarction, measuring FFR in infarct-related arteries may be different for 2 reasons: a smaller mass of viable myocardium depending on the stenotic infarct-related artery and greater microvascular resistance in the infarcted area than in the reference area. When microvascular resistance does not differ between the infarcted and the reference areas, FFR should equal relative flow reserve (RFR). RFR is the ratio of myocardial blood flow in the stenotic area to blood flow in a normally perfused reference area, at maximal hyperemia. H(2)(15)O PET measures myocardial flow within only the viable areas of an infarct and can be used to measure RFR. The present study assessed in patients with chronic myocardial infarction whether microvascular resistance in the infarct is different from that in the reference area. Therefore, the correlation between FFR and RFR using H(2)(15)O PET was studied. METHODS: In the catheterization laboratory, FFR was measured in the infarct-related artery and a reference coronary artery. The H(2)(15)O PET study and FFR measurements were performed on the same day in 22 patients. RESULTS: In 27 patients, the mean interval between the PET study and infarction was 3.3 y. Most patients had an anterior infarction, and the mean ejection fraction was 44%. The mean FFR and RFR values were 0.75 +/- 0.16 and 0.74 +/- 0.18, respectively. A significant correlation (r = 0.81; P < 0.0001) was found between FFR and RFR. The linear regression line was close to the line of identity. CONCLUSION: In patients with chronic myocardial infarction and a reduced ejection fraction, a good correlation was found between FFR measurements in the infarct-related artery and RFR. Because the linear regression line between FFR and RFR was close to the line of identity, one can conclude that microvascular resistance in the viable myocardium does not differ from that in the reference area.     

Association of no epidural analgesia with postoperative morbidity and mortality after transthoracic esophageal cancer resection

BACKGROUND: The aim of this study was to compare morbidity and mortality of patients who had epidural analgesia for at least 2 days after transthoracic esophagectomy for cancer with those who did not have epidural analgesia at all or who had it for less than 2 days. STUDY DESIGN: We analyzed 182 patients, 7 of whom were excluded. Patients were divided into two groups; 90 patients (51%) with epidural analgesia for at least 2 days (epidural group) and 85 patients (49%) who did not have epidural analgesia or had it for less than 2 days (no epidural group). To identify prognostic factors for pneumonia, univariate and multivariate logistic regression analyses were performed. RESULTS: There were no notable differences in clinicopathologic characteristics or intraoperative measurements. In favor of the epidural group, marked differences were found in pneumonia (28% versus 48%, p = 0.005), reintubation (17% versus 34%, p = 0.011), ICU-stay (median 2.8 versus 5.8 days, p = 0.001), hospital stay (median 17 versus 21 days, p = 0.015), and in-hospital mortality (0 versus 8 patients, p = 0.003). No epidural analgesia (odds ratio [OR] 2.48, 95% CI 1.30 to 4.71, p = 0.006) and atelectasis (OR 2.06, 95% CI 1.08 to 3.90, p = 0.028) were independent predictors for pneumonia. There were eight in-hospital deaths. CONCLUSIONS: No epidural analgesia for more than 2 days after a transthoracic esophageal cancer resection is associated with increased postoperative morbidity. To optimize postoperative recovery, it is of vital importance to ensure adequate epidural analgesia in these patients.     

Kinetic analysis of the cannabinoid-1 receptor PET tracer [18F]MK-9470 in human brain

Purpose

Quantitative imaging of the type 1 cannabinoid receptor (CB1R) opens perspectives for many neurological and psychiatric disorders. We characterized the kinetics and reproducibility of the CB1R tracer [¹⁸F]MK-9470 in human brain.

Methods

[¹⁸F]MK-9470 data were analysed using reversible models and the distribution volume V _T and V _ND k ₃ (V _ND k ₃ = K ₁ k ₂) were estimated. Tracer binding was also evaluated using irreversible kinetics and the irreversible uptake constant K _i and fractional uptake rate (FUR) were estimated. The effect of blood flow on these parameters was evaluated. Additionally, the possibility of determining the tracer plasma kinetics using a reduced number of blood samples was also examined.

Results

A reversible two-tissue compartment model using a global k ₄ value was necessary to describe brain kinetics. Both V _T and V _ND k ₃ were estimated satisfactorily and their test–retest variability was between 10% and 30%. Irreversible methods adequately described brain kinetics and FUR values were equivalent to K _i. The linear relationship between K _i and V _ND k ₃ demonstrated that K _i or FUR and thus the simple measure of tracer brain uptake provide CB1R availability information. The test–retest variability of K _i and FUR was <10% and estimates were independent of blood flow. Brain uptake can be used as a receptor availability index, albeit at the expense of potential bias due to between-subject differences in tracer plasma kinetics.

Conclusion

[¹⁸F]MK-9470 specific binding can be accurately determined using FUR values requiring a short scan 90 to 120 min after tracer administration. Our results suggest that [¹⁸F]MK-9470 plasma kinetics can be assessed using a few venous samples.     

Reduction of portal vein pressure with the enlargement of portal-systemic shunts: observation made in one patient

Whether portal vein pressure is reduced as spontaneous portal-systemic shunts are enlarged has long been disputed. We measured portal vein pressure directly by percutaneous transhepatic catheterization in one patient with cirrhosis at a 4-year interval, and demonstrated a significant reduction in portal vein pressure that had occurred along with enlargement of a collateral paraumbilical vein and splenorenal shunt during this period.     

A specific attentional bias in panic disorder?

According to cognitive theories, panic patients are assumed to have an attentional bias toward bodily sensations. To date, there is only some indirect evidence of such a bias measured by an emotional Stroop task. Moreover, the content and disorder specificity of this bias is rather unclear. The aim of this study was to investigate the specificity of attentional bias in patients with panic disorder (PD). Patients with PD (n=32), patients with mixed anxiety disorders (n=25), and a healthy control group (n=26) performed an emotional Stroop task with three word types: panic threat, general threat, and neutral. There were no differences on reaction times between the different groups, or on the different word types. Despite the generally accepted existence of attentional biases in anxiety disorders, we found no evidence of a specific attentional bias in patients with PD.     

8p21.3 deletions are rare causes of non-syndromic autism spectrum disorder

neurogenetics - A de novo 0.95 Mb 8p21.3 deletion had been identified in an individual with non-syndromic autism spectrum disorder (ASD) through high-resolution copy number variant analysis....     

Medial Prefrontal Cortex Has a Causal Role in Selectively Enhanced Consolidation of Emotional Memories after a 24-Hour Delay: A TBS Study

Previous research points to an association between retrieval-related activity in the medial prefrontal cortex (mPFC) and preservation of emotional information compared with co-occurring neutral information following sleep. Although the role of the mPFC in emotional memory likely begins at encoding, little research has examined how mPFC activity during encoding interacts with consolidation processes to enhance emotional memory. This issue was addressed in the present study using transcranial magnetic stimulation in conjunction with an emotional memory paradigm. Healthy young adults encoded negative and neutral scenes while undergoing concurrent TMS with a modified short intermittent theta burst stimulation (sTBS) protocol. Participants received stimulation to either the mPFC or an active control site (motor cortex) during the encoding phase. Recognition memory for scene components (objects and backgrounds) was assessed after a short delay (30 min) and a long delay [24 h (including a night of sleep)] to obtain measures of specific and gist-based memory processes. The results demonstrated that, relative to control stimulation, sTBS to the mPFC enhanced memory for negative objects on the long delay test (collapsed across specific and gist-based memory measures). mPFC stimulation had no discernable effect on memory for objects on the short delay test nor on the background images at either test. These results suggest that mPFC activity occurring during encoding interacts with consolidation processes to preferentially preserve negatively salient information.SIGNIFICANCE STATEMENT Understanding how emotional information is remembered over time is critical to understanding memory in the real world. The present study used noninvasive brain stimulation [repetitive transcranial magnetic stimulation (rTMS)] to investigate the interplay between mPFC activity that occurs during memory encoding and its subsequent interactions with consolidation processes. rTMS delivered to the mPFC during encoding enhanced memory for negatively valenced pictures on a test following a 24 h delay, with no such effect on a test occurring shortly after the encoding phase. These results are consistent with the hypothesis that emotional aspects of memories are differentially subjected to consolidation processes, and that the mPFC might contribute to this “tag-and-capture” mechanism during the initial formation of such memories.     

Mortality and revision rate of cemented and uncemented hemiarthroplasty after hip fracture: an analysis of the Dutch Arthroplasty Register (LROI)

Background and purpose — Femoral neck fractures are commonly treated with cemented or uncemented hemiarthroplasties (HA). We evaluated differences in mortality and revision rates in this fragile patient group.Patients and methods — From January 1, 2007 until December 31, 2016, 22,356 HA procedures from the Dutch Arthroplasty Register (LROI) were included. For each HA, follow-up until death, revision, or end of follow-up (December 31, 2016) was determined. The crude revision rate was determined by competing risk analysis. Multivariable Cox regression analyses were performed to evaluate the effect of fixation method (cemented vs. uncemented) on death or revision. Age, sex, BMI, Orthopaedic Data Evaluation Panel (ODEP) rating, ASA grade, surgical approach, and previous surgery were included as potential confounders.Results — 1-year mortality rates did not differ between cemented and uncemented HA. 9-year mortality rates were 53% (95% CI 52–54) in cemented HA compared to 56% (CI 54–58) in uncemented HA. Multivariable Cox regression analysis showed similar mortality between cemented and uncemented HA (HR 1.0, CI 0.96–1.1). A statistically significantly lower 9-year revision rate of 3.1% (CI 2.7–3.6) in cemented HA compared with 5.1% (CI 4.2–6.2) in the uncemented HA was found with a lower hazard ratio for revision in cemented compared with uncemented HA (HR 0.56, CI 0.47–0.67).Interpretation — Long-term mortality rates did not differ between patients with a cemented or uncemented HA after an acute femoral neck fracture. Revision rates were lower in cemented compared with uncemented HA.

The number of hemiarthroplasties (HA) after displaced femoral neck fracture increases as a result of global aging, and inferior results and high risk of reoperation after internal fixation. Although the literature on the decision to use cemented or uncemented HA may favor a cemented implant, both techniques are currently used. The use of bone cement is associated with bone cement implantation syndrome (BCIS) characterized by hypoxia, hypotension, loss of consciousness around the time of bone cementation, and intraoperative death (Olsen et al. 2014, Rutter et al. 2014). More intraoperative complications including intraoperative death were found in cemented HA in the Norwegian register (Gjertsen et al. 2012, Talsnes et al. 2013). However, no differences in mortality were found after 1 week (Costain et al. 2011, Yli-Kyyny et al. 2014). More studies including randomized controlled trials (Deangelis et al. 2012, Taylor et al. 2012) and registry studies (Costa et al. 2011, Ekman et al. 2019) did not show differences in mortality between cemented and uncemented HA. Randomized controlled trials (Taylor et al. 2012, Langslet et al. 2014, Inngul et al. 2015) and register studies (Gjertsen et al. 2012, Yli-Kyyny et al. 2014) have shown that the use of uncemented implants could result in a higher risk of periprosthetic fractures. A meta-analysis by Li et al. (2013) concluded that differences in several outcome parameters indicated cemented hemiarthroplasty to be superior to the uncemented counterpart. However, a serious flaw in this analysis is that several studies were included using an outdated stem like the Austin Moore (Sonne-Holm et al. 1982, Emery et al. 1991, Parker et al. 2010) and the experimental uncemented Thomson stem (Sadr and Arden 1977). The use of a prosthesis without Orthopaedic Data Evaluation Panel (ODEP) rating > 3A could influence outcome and is therefore discouraged (Grammatopoulos et al. 2015). A recent review by Rogmark and Leonardsson (2016) included 5 randomized studies comparing modern uncemented and cemented hemiarthroplasties. They found no differences in mortality, but more periprosthetic fractures in uncemented cases. We compared cemented and uncemented HA after an acute hip fracture with primary outcome mortality and revision rate. Data from the Dutch Arthroplasty Register (LROI) were used and the cohort of cemented HAs was compared with uncemented HAs, accounting for the ODEP rating and other confounders.     

Management of a large post-traumatic skin and bone defect using an Ilizarov frame

The authors report the case of a 28-year old male who presented with a compound diaphyseal fracture of the tibia, which was treated with intramedullary nailing. Postoperatively he required an extensive fasciotomy for an acute compartment syndrome. The fracture evolved towards post-traumatic osteomyelitis, growing methicillin-resistant Staphylococcus aureus (MRSA), combined with a large overlying soft tissue gap. An Ilizarov frame was used to treat both the bone and the skin defect. The infected fracture was treated by resection and longitudinal bone transport. Meanwhile, the skin was gradually closed using extra rods on the frame, allowing for a transverse 'skin transport'. Both the bone and the soft tissues healed without further complications.     

Opposite acute potassium and sodium shifts during transplantation of hypothermic machine perfused donor livers

Liver transplantation is frequently associated with hyperkalemia, especially after graft reperfusion. Dual hypothermic oxygenated machine perfusion (DHOPE) reduces ischemia/reperfusion injury and improves graft function, compared to conventional static cold storage (SCS). We examined the effect of DHOPE on ex situ and in vivo shifts of potassium and sodium. Potassium and sodium shifts were derived from balance measurements in a preclinical study of livers that underwent DHOPE (n = 6) or SCS alone (n = 9), followed by ex situ normothermic reperfusion. Similar measurements were performed in a clinical study of DHOPE‐preserved livers (n = 10) and control livers that were transplanted after SCS only (n = 9). During DHOPE, preclinical and clinical livers released a mean of 17 ± 2 and 34 ± 6 mmol potassium and took up 25 ± 9 and 24 ± 14 mmol sodium, respectively. After subsequent normothermic reperfusion, DHOPE‐preserved livers took up a mean of 19 ± 3 mmol potassium, while controls released 8 ± 5 mmol potassium. During liver transplantation, blood potassium levels decreased upon reperfusion of DHOPE‐preserved livers while levels increased after reperfusion of SCS‐preserved liver, delta potassium levels were ‐0.77 ± 0.20 vs. +0.64 ± 0.37 mmol/L, respectively (P = .002). While hyperkalemia is generally anticipated during transplantation of SCS‐preserved livers, reperfusion of hypothermic machine perfused livers can lead to decreased blood potassium or even hypokalemia in the recipient.