Double bypass for inoperable pancreatic malignancy at laparotomy: postoperative complications and long-term outcome

INTRODUCTION

Between 4% and 13% of patients with operable pancreatic malignancy are found unresectable at the time of surgery. Double bypass is a good option for fit patients but it is associated with high risk of postoperative complications. The aim of this study was to identify pre-operatively which patients undergoing double bypass are at high risk of complications and to assess their long-term outcome.

METHODS

Of the 576 patients undergoing pancreatic resections between 2006 and 2011, 50 patients who underwent a laparotomy for a planned pancreaticoduodenectomy had a double bypass procedure for inoperable disease. Demographic data, risk factors for postoperative complications and pre-operative anaesthetic assessment data including the Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (P-POSSUM) and cardiopulmonary exercise testing (CPET) were collected.

RESULTS

Fifty patients (33 men and 17 women) were included in the study. The median patient age was 64 years (range: 39–79 years). The complication rate was 50% and the in-hospital mortality rate was 4%. The P-POSSUM physiology subscore and low anaerobic threshold at CPET were significantly associated with postoperative complications (p=0.005 and p=0.016 respectively) but they were unable to predict them. Overall long-term survival was significantly shorter in patients with postoperative complications (9 vs 18 months). Postoperative complications were independently associated with poorer long-term survival (p=0.003, odds ratio: 3.261).

CONCLUSIONS

P-POSSUM and CPET are associated with postoperative complications but the possibility of using them for risk prediction requires further research. However, postoperative complications following double bypass have a significant impact on long-term survival and this type of surgery should therefore only be performed in specialised centres.     

Quantitative assessment of magnetic resonance derived myocardial perfusion measurements using advanced techniques: microsphere validation in an explanted pig heart system

Background

Cardiovascular Magnetic Resonance (CMR) myocardial perfusion imaging has the potential to evolve into a method allowing full quantification of myocardial blood flow (MBF) in clinical routine. Multiple quantification pathways have been proposed. However at present it remains unclear which algorithm is the most accurate. An isolated perfused, magnetic resonance (MR) compatible pig heart model allows very accurate titration of MBF and in combination with high-resolution assessment of fluorescently-labeled microspheres represents a near optimal platform for validation. We sought to investigate which algorithm is most suited to quantify myocardial perfusion by CMR at 1.5 and 3 Tesla using state of the art CMR perfusion techniques and quantification algorithms.

Methods

First-pass perfusion CMR was performed in an MR compatible blood perfused pig heart model. We acquired perfusion images at physiological flow (“rest”), reduced flow (“ischaemia”) and during adenosine-induced hyperaemia (“hyperaemia”) as well as during coronary occlusion. Perfusion CMR was performed at 1.5 Tesla (n = 4 animals) and at 3 Tesla (n = 4 animals). Fluorescently-labeled microspheres and externally controlled coronary blood flow served as reference standards for comparison of different quantification strategies, namely Fermi function deconvolution (Fermi), autoregressive moving average modelling (ARMA), exponential basis deconvolution (Exponential) and B-spline basis deconvolution (B-spline).

Results

All CMR derived MBF estimates significantly correlated with microsphere results. The best correlation was achieved with Fermi function deconvolution both at 1.5 Tesla (r = 0.93, p < 0.001) and at 3 Tesla (r = 0.9, p < 0.001). Fermi correlated significantly better with the microspheres than all other methods at 3 Tesla (p < 0.002). B-spline performed worse than Fermi and Exponential at 1.5 Tesla and showed the weakest correlation to microspheres (r = 0.74, p < 0.001). All other comparisons were not significant. At 3 Tesla exponential deconvolution performed worst (r = 0.49, p < 0.001).

Conclusions

CMR derived quantitative blood flow estimates correlate with true myocardial blood flow in a controlled animal model. Amongst the different techniques, Fermi function deconvolution was the most accurate technique at both field strengths. Perfusion CMR based on Fermi function deconvolution may therefore emerge as a useful clinical tool providing accurate quantitative blood flow assessment.     

The common 'thermolabile' variant of methylene tetrahydrofolate reductase is a major determinant of mild hyperhomocysteinaemia

Mild hyperhomocysteinaemia is a major risk factor for vascular disease and neural tube defects (NTDs), conferring an approximately three-fold relative risk for each condition. It has several possible causes: heterozygosity for rare loss of function mutations in the genes for 5,10-methylene tetrahydrofolate reductase (MTHFR) or cystathionine-&bgr;-synthase (CBS); dietary insufficiency of vitamin co-factors B6, B12 or folates; or homozygosity for a common 'thermolabile' mutation in the MTHFR gene which has also been associated with vascular disease and NTDs. We quantified the contribution of the thermolabile mutation to the hyperhomocysteinaemic phenotype in a working male population (625 individuals). Serum folate and vitamin B12 concentrations were also measured and their relationship with homocysteine status and MTHFR genotype assessed. The homozygous thermolabile genotype occurred in 48.4, 35.5, and 23.4% for the top 5, 10 and 20% of individuals repectively) ranked by plasma homocysteine levels, compared with a frequency of 11.5% in the study population as a whole establishing that the mutation is a major determinant of homocystein levels at the upper end of the range. Serum folate concentrations also varied with genotype, being lowest in thermolabile homozygotes. The MTHFR thermolabile genotype should be considered when population studies are designed to determine the effective homocysteine-lowering dose of dietary folate supplements, and when prophylactic doses of folate are recommended for individuals.      

Detection of cytomegalovirus antibody in platelet concentrates by fluorescence immunoassay and latex agglutination

A passive latex agglutination (PLA) test for cytomegalovirus (CMV) antibody detection has been shown to be an acceptable method of screening both donor sera and plasma from units of red cells and platelets stored in CPDA-1. However, most plateletpheresis concentrates are collected in ACD, and CMV antibody testing of ACD-stored products has not been systematically evaluated by PLA. Sera and ACD-stored platelet concentrate bag segments from 104 donors were tested by PLA and by a solid-phase fluorescence immunoassay (FIAX) as a reference standard for CMV-IgM and CMV-IgG antibodies. Sera were stored at both 4 and 22 degrees C and were tested on Days 1 and 5 of storage; segments were tested daily for 5 days. Of 63 donor samples (61%) that tested negative for CMV-IgG by FIAX, there were two false-positive results in bag segments by PLA testing, one on Day 1 and the other on Day 2 of storage. PLA testing was consistently positive in sera and segments in the 40 donors (38%) who tested positive for CMV-IgG by FIAX. Potential false-negative PLA results occurred in five bag segments derived from one donor whose serum gave equivocal CMV-IgG results on FIAX. The sensitivity and specificity of the PLA assay were 100 percent for donor sera tested at both 4 and 22 degrees C and 91.5 and 98.4 percent, respectively, for platelet bag segment tests. Although no donors positive for CMV-IgM were identified, 15 (14.4%) had equivocal IgM anti-CMV test results.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anesthesia systems. Part II: Operating principles of fundamental components

This second article in a 2-part series on the operation of principal components within Narkomed anesthesia systems describes the function and compensation mechanisms of the Dräger 19.n vaporizer, the operating principles of the anesthesia ventilator-electronic, the structure and mechanics of the pressure limit control, and the 3 basic monitoring systems built into the anesthesia system. Part II of this series builds on the data published in part I (J Clin Monit 1992;8:295–307).     

Detection of human immunodeficiency virus type 1 p24 antigen and plasma RNA: relevance to indeterminate serologic tests

BACKGROUND: Most enzyme immunoassay-reactive specimens producing indeterminate Western blot results belong to individuals who are not infected with human immunodeficiency virus type 1 (HIV-1). However, a small percentage may correspond to early seroconversion or advanced disease, at which stage partial reactivity on Western blot may be observed. STUDY DESIGN AND METHODS: To determine the utility of HIV-1 p24 antigen and cell-free RNA detection for the resolution of Western blot-indeterminate serologic results, several types of enzyme immunoassay-positive, sero-indeterminate specimens were analyzed. Samples were obtained from infected individuals at the time of seroconversion (n = 20), from patients with AIDS (n = 2), as specimens from clinical samples obtained for diagnostic testing (n = 57), from blood donors producing persistent indeterminate results (n = 47), and from random blood donors (n = 72). RESULTS: HIV-1 p24 antigen was detected in 10 of 20 specimens collected from 9 of 12 individuals who seroconverted and in 2 of 2 AIDS patients. HIV-1 plasma RNA was positive in 22 of 22 samples from those 14 individuals. All of 57 diagnostic specimens and 47 samples obtained from persistently indeterminate donors were negative for HIV-1 p24 antigen and plasma HIV- 1 RNA. One of 72 blood donor specimens was positive for HIV-1 plasma RNA and had borderline reactivity for p24 antigen. CONCLUSION: The detection of plasma RNA appears to be sensitive and specific; negative test results may be used to identify false-positive serologic reactions. The detection of p24 antigen and plasma RNA can also be used to confirm HIV-1 infection in persons with indeterminate serologic results associated with early seroconversion or late-stage disease.     

Cutaneous mastocytosis in children: a clinical analysis of 71 cases

OBJECTIVE: To characterize the clinical features, response to therapy, evolution and prognosis of cutaneous mastocytosis in children. BACKGROUND: Mastocytosis in children, instead of being induced by a potentially oncogenic c-kit mutation, is probably a clonal disease with benign prognosis. METHODS: The clinicopathological features, evolution and response to treatment were analysed in 71 children with mastocytosis. RESULTS: There were 53 (75%) cases of urticaria pigmentosa, 12 (17%) cases of mastocytoma, and six (8%) cases of diffuse cutaneous mastocytosis. In 92% of cases disease onset was in the first year of life. There was a male predominance 1.8 : 1. Treatment did not modify the disease evolution. Eighty per cent of patients improved or had spontaneous resolution of the disease. CONCLUSION: The most frequent clinical form of mastocytosis was urticaria pigmentosa followed by mastocytoma and diffuse cutaneous mastocytosis. Darier's sign was present in 94% of cases. A negative Darier's sign does not rule out mastocytosis. In contrast to adults, mastocytosis in children usually has a benign course making sophisticated or invasive diagnostic tests unnecessary. A classification of paediatric cutaneous mastocytosis is proposed.     

Prevalence and risk factors for diabetic peripheral neuropathy,neuropathic pain and foot ulceration in the Arabian Gulf region

Aims/IntroductionThis study determined the prevalence and risk factors for diabetic peripheral neuropathy (DPN), painful DPN and diabetic foot ulceration (DFU) in patients with type 2 diabetes in secondary healthcare in Qatar, Kuwait and the Kingdom of Saudi Arabia.Materials and MethodsAdults aged 18–85 years with type 2 diabetes were randomly enrolled from secondary healthcare, and underwent clinical and metabolic assessment. DPN was evaluated using vibration perception threshold and neuropathic symptoms and painful Diabetic Peripheral Neuropathy was evaluated using the Douleur Neuropathique 4 questionnaire.ResultsA total of 3,021 individuals were recruited between June 2017 and May 2019. The prevalence of DPN was 33.3%, of whom 52.2% were at risk of DFU and 53.6% were undiagnosed. The prevalence of painful DPN was 43.3%, of whom 54.3% were undiagnosed. DFU was present in 2.9%. The adjusted odds ratios for DPN and painful DPN were higher with increasing diabetes duration, obesity, poor glycemic control and hyperlipidemia, and lower with greater physical activity. The adjusted odds ratio for DFU was higher with the presence of DPN, severe loss of vibration perception, hypertension and vitamin D deficiency.ConclusionsThis is the largest study to date from the Middle East showing a high prevalence of undiagnosed DPN, painful DPN and those at risk of DFU in patients with type 2 diabetes, and identifies their respective risk factors.     

Characteristics of pulsed electric field cardiac ablation porcine treatment zones with a focal catheter

Objectives

Pulsed electric field (PEF) therapies employ punctuated energy delivery to kill cells in a volume of tissue through mechanisms that are not dependent on thermal processes. A key component to successful cardiac ablation procedures is ensuring the generation of transmural, contiguous ablation zones, which requires in-depth knowledge regarding treatment sizes for a given therapeutic application.

Methods

In this study, a series of acute treatments were delivered to porcine ventricles, where triphenyl tetrazolium chloride (TTC) vitality stain was used to identify treatment effect sizes for the three focal monopolar CENTAURI PEF cardiac ablation energy settings.

Results

Treatment depths were 5.7, 7.2, and 8.2 mm for the 19, 22, and 25 A energy settings, respectively. Gross pathology indicated umbral zones of hemorrhage surrounded by pale avital TTC-negative-negative tissue, which contrasted significantly from radiofrequency ablation (RF) controls. Histologically, treatment zones are identified by regions of contraction band necrosis and cardiomyocytolysis, which contrasted with RF control lesions composed primarily of coagulation necrosis.

Conclusions

Together, these data indicate the ability for focal monopolar PEF treatments to generate deep treatment zones in cardiac ablation without incurring the gross or histological coagulative characteristics of RF thermal lesions.     

Peripheral T-cell lymphoma with a T follicular-helper phenotype: A different entity? Results of the Spanish Real-T study

Nodal peripheral T-cell lymphoma (PTCL) with a T follicular helper phenotype (PTCL-TFH) is a new type of PTCL. We aimed to define its clinical characteristics and prognosis compared to PTCL not otherwise specified (PTCL-NOS) and angioimmunoblastic T-cell lymphoma (AITL). This retrospective observational study included 175 patients diagnosed with PTCL between 2008 and 2013 in 13 Spanish sites. Patient diagnosis was centrally reviewed, and patients were reclassified according to the World Health Organization (WHO) 2016 criteria: 21 patients as PTCL-NOS, 55 as AITL and 23 as PTCL-TFH. Median follow-up was 56.07 months (95% CI 38.7–73.4). Progression-free survival (PFS) and overall survival (OS) were significantly higher in patients with PTCL-TFH than in those with PTCL-NOS and AITL (PFS, 24.6 months vs. 4.6 and 7.8 months, respectively, p = 0.002; OS, 52.6 months vs. 10.0 and 19.3 months, respectively, p < 0.001). Histological diagnosis maintained an independent influence on both PFS (hazard ratio [HR] 4.1 vs. PTCL-NOS, p = 0.008; HR 2.6 vs. AITL, p = 0.047) and OS (HR 5.7 vs. PTCL-NOS, p = 0.004; HR 2.6 vs. AITL, p = 0.096), regardless of the International Prognostic Index. These results suggest that PTCL-TFH could have more favourable features and prognosis than the other PTCL subtypes, although larger series are needed to corroborate these findings.