Arterial Complications following Total Knee Arthroplasty (TKA): A Systematic Review and Proposal for Improved Monitoring

@#Introduction: Total knee arthroplasty (TKA) is a common operation and is becoming more common due to population aging and increasing BMI. TKA provides excellent improvement in quality of life but carries risk of arterial complications in the perioperative period. This systematic review aims to provide a greater understanding of the incidence of such complications, and time taken to diagnose arterial injury. Materials and methods: PubMed, Medline, Ovid SP and EMBASE databases were searched with the following MeSH keywords: ‘complication’, ‘vascular injury’, ‘ischaemia’, ‘spasm’, ‘thrombosis’, ‘pseudoaneurysm’, ‘transection’, ‘pulse’, ‘ABPI OR ABI’, ‘Doppler’, ‘amputation’. All arterial vascular events in the perioperative state of the total knee replacement were included. Records were independently screened by two reviewers, and data was extracted according to a pre-determined proforma. Overall incidence and time to diagnosis was calculated for complications. Systematic review registration PROSPERO: CRD42018086643. No funding was received. Results: Twelve studies were selected for inclusion. A total of 3325 cases of arterial complications were recorded across all studies, and were divided into three categories, pseudoaneurysms (0.06%); ischaemia and thrombosis (0.17%); haemorrhage and arterial transections (0.07%). Time taken to reach the diagnosis for each complication was longest in the ischaemia and thrombosis group (6.8 days), followed by pseudoaneurysm (3.5 days) and haemorrhage and transections (3.0 days). Conclusion: TKA post-operative vascular complications are rare, but when they do occur they lead to limb and life threatening complications. This should be discussed with patients during the consent process. Current times to diagnosis represent missed opportunities to recognise arterial injury and facilitate rapid treatment of the complication. A very low threshold for seeking specialist input should be adopted, and any concern for vascular injury, such as unexplained perioperative bleeding, absent lower limb pulses in the post-operative period or unexplained severe pain should warrant immediate review by a vascular surgeon, and in centres where this is not possible, immediate bluelight transfer to the closest vascular centre

Vitamin D Activities for Health Outcomes

Reports describing significant health risks due to inadequate vitamin D status continue to generate considerable interest amongst the medical and lay communities alike. Recent research on the various molecular activities of the vitamin D system, including the nuclear vitamin D receptor and other receptors for 1,25-dihydroxyvitamin D and vitamin D metabolism, provides evidence that the vitamin D system carries out biological activities across a wide range of tissues similar to other nuclear receptor hormones. This knowledge provides physiological plausibility of the various health benefits claimed to be provided by vitamin D and supports the proposals for conducting clinical trials. The vitamin D system plays critical roles in the maintenance of plasma calcium and phosphate and bone mineral homeostasis. Recent evidence confirms that plasma calcium homeostasis is the critical factor modulating vitamin D activity. Vitamin D activities in the skeleton include stimulation or inhibition of bone resorption and inhibition or stimulation of bone formation. The three major bone cell types, which are osteoblasts, osteocytes and osteoclasts, can all respond to vitamin D via the classical nuclear vitamin D receptor and metabolize 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D to activate the vitamin D receptor and modulate gene expression. Dietary calcium intake interacts with vitamin D metabolism at both the renal and bone tissue levels to direct either a catabolic action on the bone through the endocrine system when calcium intake is inadequate or an anabolic action through a bone autocrine or paracrine system when calcium intake is sufficient.

A Comparative Review of the Hemodynamics and Pathogenesis of Cerebral and Abdominal Aortic Aneurysms: Lessons to Learn From Each Other

OBJECTIVE: Cerebral aneurysms (CAs) and abdominal aortic aneurysms (AAAs) are degenerative vascular pathologies that manifest as abnormal dilations of the arterial wall. They arise with different morphologies in different types of blood vessels under different hemodynamic conditions. Although treated as different pathologies, we examine common pathways in their hemodynamic pathogenesis in order to elucidate mechanisms of formation. MATERIALS AND METHODS: A systematic review of the literature was performed. Current concepts on pathogenesis and hemodynamics were collected and compared. RESULTS: CAs arise as saccular dilations on the cerebral arteries of the circle of Willis under high blood flow, high wall shear stress (WSS), and high wall shear stress gradient (WSSG) conditions. AAAs arise as fusiform dilations on the infrarenal aorta under low blood flow, low, oscillating WSS, and high WSSG conditions. While at opposite ends of the WSS spectrum, they share high WSSG, a critical factor in arterial remodeling. This alone may not be enough to initiate aneurysm formation, but may ignite a cascade of downstream events that leads to aneurysm development. Despite differences in morphology and the structure, CAs and AAAs share many histopathological and biomechanical characteristics. Endothelial cell damage, loss of elastin, and smooth muscle cell loss are universal findings in CAs and AAAs. Increased matrix metalloproteinases and other proteinases, reactive oxygen species, and inflammation also contribute to the pathogenesis of both aneurysms. CONCLUSION: Our review revealed similar pathways in seemingly different pathologies. We also highlight the need for cross-disciplinary studies to aid in finding similarities between pathologies.

Algunos aspectos relevantes de la enfermedad de Chagas en Chile / Chaga's disease in Chile

La infección por T. cruzi (enfermedad de Chagas) constituye un problema de salud pública en Chile. tiene carácter endemo-enzoótico en sectores rurales y periféricos de las siete primeras regiones político-administrativas del país. Se registra una poporción significativa de infección por el parásito en habitantes de ciudades ubicadas en las regiones antes mencionadas, debido muy posiblemente a migración rural - urbana. 2.- El T. infestans es el vector domiciliario practicamente único de la parasitosis. Las tasas de infestación domiciliaria, cuyo promedio es de 29,4%, varían entre 9,3% y 65,2%, siendo en general más altas en las regiones III y IV. 3.- La infección promedia por T. cruzi de los T. infestans es de 18,7%, variando entre 6,4% y 47,6% registrándose los porcentajes más latos en las regiones II y III. Las tasas de infección de los triatominos, ocn un promedio de 19,6%, van en aumento según su edad, desde un 5,8% en los estadios II - III hasta un 25,4% en los imagos. Las fuentes de alimentación de los triatomídeos están constituídas principalmente por sangre de mamíferos y aves, alcanzando a un 90,8%, en la de los primeros, correspondiendo al hombre el 68,4%. Como era de esperar, las tasas deinfección por T. cruzi de los triatomas, fueron mayores en aquellos que se alimentaron con sangre de mamíferos. 4.- La infección chagásica humana, diagnosticada por medio de la RHAI correspondiente, fue en general de 16,9%, oscilando entre un 7,0% y un 33,2%, siendo las regiones III y IV las con más altos índices de infección. Las tasas de infección fueron similares para hombres y mujeres con un 17,7% y un 16,3% respectivamente. como es natural, se registró un incrmento progresivo de los valores de dichas tasas desde los grupos de menor edad (5,7%) hasta los grupos de mayores de 60 años (35,8%)...

Leishmaniasis cutánea en Panamá: un breve resumen / Cutaneous leishmaniasis in Panama: a brief summary

El Laboratorio Conmemorativo Gorgas (LCG) se ha dedicado a estudios epidemiológicos sobre Leishmaniasis Cutánea durante las últimas cuatro décadas. Se presenta un corto resumen de los hallazgos efectuados por científicos del LCG durante este período en cuanto a los parásitos, reservorio y vectores