From heart to muscle: Pathophysiological mechanisms underlying long-term physical sequelae from SARS-CoV-2 infection

The long-term sequelae of the coronavirus disease 2019 (COVID-19) are multifaceted and, besides the lungs, impact other organs and tissues, even in cases of mild infection. Along with commonly reported symptoms such as fatigue and dyspnea, a significant proportion of those with prior COVID-19 infection also exhibit signs of cardiac damage, muscle weakness, and ultimately, poor exercise tolerance. This review provides an overview of evidence indicating cardiac impairments and persistent endothelial dysfunction in the peripheral vasculature of those previously infected with COVID-19, irrespective of the severity of the acute phase of illness. Additionally, VO2peak appears to be lower in convalescent patients, which may stem, in part, from alterations in O2 transport such as impaired diffusional O2conductance. Together, the persistent multi-organ dysfunction induced by COVID-19 may set previously healthy individuals on a trajectory towards frailty and disease. Given the large proportion of individuals recovering from COVID-19, it is critically important to better understand the physical sequelae of COVID-19, the underlying biological mechanisms contributing to these outcomes, and the long-term effects on future disease risk. This review highlights relevant literature on the pathophysiology post-COVID-19 infection, gaps in the literature, and emphasizes the need for the development of evidence-based rehabilitation guidelines.

Bioheat Transfer Basis of Human Thermoregulation: Principles and Applications

Thermoregulation is a process that is essential to the maintenance of life for all warm-blooded mammalian and avian species. It sustains a constant core body temperature in the face of a wide array of environmental thermal conditions and intensity of physical activities that generate internal heat. A primary component of thermoregulatory function is the movement of heat between the body core and the surface via the circulation of blood. The peripheral vasculature acts as a forced convection heat exchanger between blood and local peripheral tissues enabling heat to be conducted to the skin surface where is may be transferred to and from the environment via conduction, convection, radiation, and/or evaporation of water as local conditions dictate. Humans have evolved a particular vascular structure in glabrous (hairless) skin that is especially well suited for heat exchange. These vessels are called arteriovenous anastomoses (AVAs) and can vasodilate to large diameters and accommodate high flow rates. We report herein a new technology based on a physiological principle that enables simple and safe access to the thermoregulatory control system that allow manipulation of thermoregulatory function. The technology operates by applying a small amount of heating local to control tissue on the body surface overlying the cerebral spine that upregulates AVA perfusion. Under this action, heat exchangers can be applied to glabrous skin, preferably on the palms and soles, to alter the temperature of elevated blood flow prior to its return to the core. Therapeutic and prophylactic applications are discussed.

Case report: End of life care via a mid-thigh femoral midline catheter

Maintaining peripheral vascular access represents a major challenge for medical providers and patients leading to the emergence of ultrasound guided vascular access teams. Upper extremity peripheral vascular access options are often limited in the chronically ill patient population with end stage cancer, patients with severe contractures, tracheostomies, and feeding tubes and patients referred for palliative care are just some examples of patients who live with difficult access. The following is a case description of a mid-thigh superficial femoral vein midline catheter for comfort care medications in a patient with exhausted peripheral vasculature on hospice.

A proposed framework for cerebral venous congestion

Background While venous congestion in the peripheral vasculature has been described and accepted, intracranial venous congestion remains poorly understood. The characteristics, pathophysiology, and management of cerebral venous stasis, venous hypertension and venous congestion remain controversial, and a unifying conceptual schema is absent. The cerebral venous and lymphatic systems are part of a complex and dynamic interaction between the intracranial compartments, with interplay between the parenchyma, veins, arteries, cerebrospinal fluid, and recently characterized lymphatic-like systems in the brain. Each component contributes towards intracranial pressure, occupying space within the fixed calvarial volume. This article proposes a framework to consider conditions resulting in brain and neck venous congestion, and seeks to expedite further study of cerebral venous diagnoses, mechanisms, symptomatology, and treatments. Methods A multi-institution retrospective review was performed to identify unique patient cases, complemented with a published case series to assess a spectrum of disease states with components of venous congestion affecting the brain. These diseases were organized according to anatomical location and purported mechanisms. Outcomes of treatments were also analyzed. Illustrative cases were identified in the venous treatment databases of the authors. Conclusion This framework is the first clinically structured description of venous pathologies resulting in intracranial venous and cerebrospinal fluid hypertension. Our proposed system highlights unique clinical symptoms and features critical for appropriate diagnostic work-up and potential treatment. This novel schema allows clinicians effectively to approach cases of intracranial hypertension secondary to venous etiologies, and furthermore provides a framework by which researchers can better understand this developing area of cerebrovascular disease.

Impact of a Peripheral Vascular Access Service on Device Use

Background More than 1 billion peripheral vascular access devices are inserted annually worldwide with potential complications including infection, thrombosis, and vasculature damage. Vasculature damage can necessitate the use of central catheters, which carry additional risks such as central catheter–associated bloodstream infections. To address these concerns, one institution used expert nurses and a consult request system with algorithms embedded in the electronic medical record. Objectives To develop a uniform process for catheter insertion by means of a peripheral vascular access service dedicated to selecting, placing, and maintaining all inpatient peripheral catheters outside of the intensive care units. Methods Descriptive analysis and χ2 analysis were done to describe the impact of the peripheral vascular access service. Results In 2018, 6246 consults were reviewed. Of these, 26% did not require vascular access. Similarly, in 2019, 7861 consults were reviewed, and 35.3% did not require vascular access. Use of central catheters decreased from 21% in 2017 to 17% in 2018 and 2019. Conclusions The peripheral vascular access service allowed patients to receive appropriate peripheral vascular access devices and avoid unnecessary peripheral catheter placements. This may have preserved patients’ peripheral vasculature and thus prevented premature central catheter placement and contributed to an overall decrease in central catheter days. With the peripheral vascular access service, peripheral vascular access devices were selected, placed, and maintained by experts with a standardized process that promoted a culture of quality and patient safety.

Clinical experience with a shape memory polymer peripheral vascular embolisation plug: a case series

Background Shape memory polymers are materials that are manufactured in a certain shape, can be stored in a temporary deformed shape, and then return to – or remember – their original shape upon exposure to external stimuli such as temperature and moisture. This property lends itself to application in endovascular medical devices. Peripheral vasculature embolisation devices incorporating this novel technology have become commercially available and this case series, where the data were collected as part of a post market registry, outlines initial clinical experience with these novel devices. Results Eight cases are described in this series. The disease state/conditions for which embolisation was indicated were right common iliac artery aneurysms (n = 3), a type II endoleak into the thoracic aorta following thoracic endovascular aneurysm repair (n = 1), a left inferior gluteal artery aneurysm (n = 1), left internal iliac artery aneurysms (n = 2), and a case of splenomegaly, where splenectomy was planned after the embolisation procedure (n = 1). Target arteries were 5–10 mm in diameter. In each case, at least one IMPEDE Embolization Plug (IMP-Device) of an appropriate diameter was used. All procedures were technically successful and target vessel thrombosis was achieved in all cases. Follow-up imaging available during the 45–90-day data collection timeframe showed sustained vessel occlusion. This case series includes examples of situations commonly encountered when embolising the peripheral vasculature, namely, the use of one or multiple devices in a single vessel and in combination with the use of other embolic devices (e.g., microcoils, gelatin sponge, and PVA particles) in the same case. There were no adverse events related to the specific use of the device. Conclusions This small series illustrates the safety and efficacy of this novel sponge-based embolic device for the embolisation of small and medium sized arteries and further experience will demonstrate the utility of the shape memory polymer devices.

The Outback Re-Entry Device. A Pictorial Review

The Outback™ Elite re-entry catheter (CORDIS, Cardinal Health, USA) is designed to facilitate placement and positioning of guidewires within the peripheral vasculature and allows for re-entry of a guidewire back into the true lumen of a vessel following a subintimal crossing of an arterial occlusion. The device was first introduced in 2005 and has become widely utilized in a variety of situations involving both arterial and venous interventions. This article aims to share our experiences with the Outback™ device and inform interventionalists of its utility and versatility.

Clinical Experience With a Shape Memory Polymer Peripheral Vascular Embolisation Plug: A Case Series

Background: Shape memory polymers are materials that are manufactured in a certain shape, can be stored in a temporary deformed shape, and then return to – or remember – their original shape upon exposure to external stimuli such as temperature and moisture. This property lends itself to application in endovascular medical devices. Peripheral vasculature embolisation devices incorporating this novel technology have become commercially available and this case series, where the data were collected as part of a post market registry, outlines initial clinical experience with these novel devices.Results: Eight cases are described in this series. The disease state/conditions for which embolisation was indicated were right common iliac artery aneurysms (n = 3), a type II endoleak into the thoracic aorta following thoracic endovascular aneurysm repair (n = 1), a left inferior gluteal artery aneurysm (n = 1), left internal iliac artery aneurysms (n = 2), and a case of splenomegaly, where splenectomy was planned after the embolisation procedure (n = 1). Target arteries were 5-10 mm in diameter. In each case, at least one IMPEDE Embolization Plug of an appropriate diameter was used. All procedures were technically successful and target vessel thrombosis was achieved in all cases. Follow-up imaging available during the 45-90-day data collection timeframe showed sustained vessel occlusion. This case series includes examples of situations commonly encountered when embolising the peripheral vasculature, namely, the use of one or multiple devices in a single vessel and in combination with the use of other embolic devices (e.g., microcoils, gelatin sponge, and PVA particles) in the same case. There were no adverse events related to the specific use of the device.Conclusions: This small series illustrates the safety and efficacy of this novel sponge-based embolic device for the embolisation of small and medium sized arteries and further experience will demonstrate the utility of the shape memory polymer devices.