Novel, digital, chest drainage system in cardiac surgery.

BACKGROUND: A new, self-contained, digital, continuous pump-driven chest drainage system is compared in a randomized control trial to a traditional wall-suction system in cardiac surgery. METHODS: One hundred and twenty adult elective cardiac patients undergoing coronary artery bypass graft and/or valve surgery were randomized to the study or control group. Both groups had similar pre/intra-operative demographics: age 67.8 vs 67.0 years, Euroscore 2.3 vs 2.2, and body surface area 1.92 vs 1.91 m2 . Additionally, a satisfaction assessment score (0-10) was performed by 52 staff members. RESULTS: Given homogenous intra-operative variables, total chest-tube drainage was comparable among groups (566 vs 640 mL; ns), but the study group showed more efficient fluid collection during the early postoperative phase due to continuous suction (P = .01). Blood, cell saver transfusions and postoperative hemoglobin values were similar in both groups. The study group experienced drain removal after 29.8 vs 38.4 hours in the control group (ns). Seven crossovers from the Study to the Control group were registered but no patient had drain-related complications. The Personnel Satisfaction Assessment scored above 5 for all questions asked. CONCLUSIONS: The new, digital, chest drainage system showed better early drainage of the chest cavity and was as reliable as conventional systems. Quicker drain removal might impact on intensive care unit (ICU) stay and reduce costs. Additional advantages are portable size, battery operation, patient mobility, noiseless function, digital indications and alarms. The satisfaction assessment of the new system by the staff revealed a higher score when compared to the traditional wall suction chest drainage system.

Risk of Burns During Active External Rewarming for Accidental Hypothermia.

This article describes 3 incidents in which therapeutic or experimental warming of cold individuals caused first- to third-degree burns to the skin. Mechanisms for these injuries are considered. We conclude that active external rewarming of the trunk of a cold patient in the field can be administered safely and burn risk reduced if 1) manufacturer instructions are followed; 2) insulation is placed between the skin the and heat source; and 3) caregivers make regular efforts to observe heated skin for possible pending burn injury. Direct inspection is mandatory for the skin of areas that are on top of a heat source when the patient is lying on the heat source.

Wilderness Medical Society Clinical Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2019 Update.

To provide guidance to clinicians, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and a balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is the 2019 update of the Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2014 Update.

Biodegradable and plasma-treated electrospun scaffolds coated with recombinant Olfactomedin-like 3 for accelerating wound healing and tissue regeneration.

Three-dimensional biomimetic scaffolds resembling the native extracellular matrix (ECM) are widely used in tissue engineering, however they often lack optimal bioactive cues needed for acceleration of cell proliferation, neovascularization, and tissue regeneration. In this study, the use of the ECM-related protein Olfactomedin-like 3 (Olfml3) demonstrates the importance and feasibility of fabricating efficient bioactive scaffolds without in vitro cell seeding prior to in vivo implantation. First, in vivo proangiogenic properties of Olfml3 were shown in a murine wound healing model by accelerated wound closure and a 1.4-fold increase in wound vascularity. Second, subcutaneous implantation of tubular scaffolds coated with recombinant Olfml3 resulted in enhanced cell in-growth and neovascularization compared with control scaffolds. Together, our data indicates the potential of Olfml3 to accelerate neovascularization during tissue regeneration by promoting endothelial cell proliferation and migration. This study provides a promising concept for the reconstruction of damaged tissue using affordable and effective bioactive scaffolds.

Porcine carotid artery replacement with biodegradable electrospun poly-e-caprolactone vascular prosthesis.

OBJECTIVE: There is a continuous search for shelf-ready small-caliber vascular prostheses with satisfactory early and late results. Biodegradable scaffolds, repopulated by recipient's cells regenerating a neovessel, can be a suitable option for adult and pediatric, urgent and elective cardiovascular procedures. METHODS: This was a short-term experimental assessment of a new biodegradable vascular prosthesis for arterial replacement in the pig. Eleven pigs underwent bilateral carotid artery replacement with biodegradable electrospun poly-ε-caprolactone (PCL) nanofiber prostheses (internal diameter, 4 mm; length, 5 cm); or expanded polytetrafluoroethylene (ePTFE) prostheses as control. Perioperative anticoagulation was achieved with intravenous heparin (double baseline activated clotting time). Postoperatively, until conclusion of the study at 1 month, animals received aspirin and clopidogrel daily. Transit time flow was measured intraoperatively and at sacrifice. Doppler ultrasound (1 and 4 weeks) and a selective carotid angiography (4 weeks) were performed to assess patency. All explanted grafts were analyzed by histology, morphometry, and scanning electron microscopy in order to study graft-host interaction. RESULTS: Surgical handling and hemostasis of the new prostheses were excellent. Patency rate was 78% (7/9) for PCL grafts, compared with 67% (4/6) for ePTFE grafts. Transit time flow and Doppler ultrasound showed no significant changes in flow and velocity or diameter over time in both groups. Both prostheses showed no detectable in vivo compliance as compared with native carotid artery. Percent neoendothelialization was 86% for PCL and 58% for ePTFE grafts (P = .008). Neointima formation was equal in both grafts. More adventitial infiltration of macrophages, myofibroblasts, and capillaries was seen in PCL grafts with a milder foreign-body reaction when compared with ePTFE implants. Both grafts showed similar endoluminal thrombus formation. CONCLUSIONS: Biodegradable, electrospun PCL grafts showed good surgical and mechanical properties, no aneurysm formation, and similar short-term patency compared with ePTFE grafts. Rapid endothelialization and cell ingrowth confirms favorable PCL graft-recipient biological interaction. Despite good early results, long-term follow-up is required before clinical application.

Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia.

To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations.

Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia: 2014 update.

To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is an updated version of the original Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia published in Wilderness & Environmental Medicine 2014;25(4):425-445.

Extracorporeal Rewarming Is Associated With Increased Survival Rate in Severely Hypothermic Patients With Preserved Spontaneous Circulation.

Treatment recommendations for rewarming patients in severe accidental hypothermia with preserved spontaneous circulation have a weak evidence due to the absence of randomized clinical trials. We aimed to compare the outcomes of extracorporeal versus less-invasive rewarming of severely hypothermic patients with preserved spontaneous circulation. We conducted a multicenter retrospective study. The patient population was compiled based on data from the HELP Registry, the International Hypothermia Registry, and a literature review. Adult patients with a core temperature <28°C and preserved spontaneous circulation were included. Patients who underwent extracorporeal rewarming were compared with patients rewarmed with less-invasive methods, using a matched-pair analysis. The study population consisted of 50 patients rewarmed extracorporeally and 85 patients rewarmed with other, less-invasive methods. Variables significantly associated with survival included: lower age; outdoor cooling circumstances; higher blood pressure; higher PaCO 2 ; higher BE; higher HCO 3 ; and the absence of comorbidities. The survival rate was higher in patients rewarmed extracorporeally ( p = 0.049). The relative risk of death was twice as high in patients rewarmed less invasively. Based on our data, we conclude that patients in severe accidental hypothermia with circulatory instability can benefit from extracorporeal rewarming without an increased risk of complications.

Successful Pre-Rewarming Resuscitation after Cardiac Arrest in Severe Hypothermia: A Retrospective Cohort Study from the International Hypothermia Registry.

The aim of our study is to investigate successful pre-rewarming resuscitation after hypothermic cardiac arrest (HCA). The hypothermic heart may be insensitive to defibrillation when core temperature is below 30 °C and after successful defibrillation, sinus rhythm often returns into ventricular fibrillation. Recurrent defibrillation attempts may induce myocardial injury. Discrepancy exists concerning pre-rewarming defibrillation between the guidelines of the European Resuscitation Council and American Heart Association. The International Hypothermia Registry (IHR) gathers hypothermia cases. The primary outcome was survival. Secondary outcomes were the characteristics of defibrillation, the effect of Adrenaline administration under 30 °C, and the duration of CPR. Of the 239 patients, eighty-eight were in cardiac arrest at arrival of the rescue team. Successful pre-rewarming resuscitation was obtained in 14 patients. The outcome showed: seven deaths, one vegetative state, two patients with reversible damage, and four patients with full recovery. A total of five patients had a shockable rhythm, and defibrillation was successful in four patients. The response rate to Adrenaline was reported as normal in six patients. There were no statistically significant differences in the presence of a shockable rhythm, the success of defibrillation, and the effect on Adrenaline administration between the survivors and non-survivors. Successful resuscitation in severe hypothermia is possible before active rewarming and arrival in the hospital, thus improving the chance of survival.

Catheter tip force required for mechanical perforation of porcine cardiac chambers.

AIMS: Catheter manipulation during ablation procedures can produce injury and tamponade. We evaluated the mechanical forces required to perforate a porcine heart with an ablation catheter. METHODS AND RESULTS: A 7 Fr, 3.5 mm irrigated radiofrequency (RF) ablation catheter with a force sensor (FS) within its tip was used to create right atrial (RA) free wall lesions in pigs. The intact heart was removed and the FS-equipped catheter was used to mechanically perforate (without RF delivery) the free walls of both atria and ventricles: directly and through an introducer sheath to prevent catheter shaft buckling. Perforation was also performed through epicardially visible RA lesions and adjacent unablated tissue. Twenty-four RA free wall lesions were created in four pigs. One hundred and forty-four mechanical perforations were performed: 44 RA, 30 left atrial (LA), 37 right ventricular (RV), and 33 left ventricular (LV). The RA and RV perforation force (PF) was lower than through the LA and LV (P<0.0001). The LV perforation time was shorter when the catheter was gripped through an introducer sheath (0.8±0.5 vs. 3.2±3 s, P<0.0001). Perforation force through transmural RA lesions was lower than through unablated RA tissue (172.4±79.1 vs. 300.6±116.8 g, P<0.0002). CONCLUSION: The force threshold for mechanical perforation in the porcine heart is lower for right- compared with left-sided chambers, and also lower through recently created RA RF lesions compared with unablated RA tissue. Left ventricular perforation is achieved more rapidly with the ablation catheter in a sheath despite the same PF because the sheath prevents catheter buckling.

A biodegradable ring enables growth of the native tricuspid annulus.

BACKGROUND AND AIM OF THE STUDY: The study aim was to assess the growth potential and function of the tricuspid valve (TV) annulus after annuloplasty with the intra-annular biodegradable ring. METHODS: Among 11 children (median age 4.5 years; age range: 0.2-10.9 years) who underwent surgery for severe congenital TV regurgitation, valve repair was completed using a biodegradable annuloplasty ring. The children were followed regularly using transthoracic echocardiography, whereby the TV annulus lateral diameter (TVALD) and valve function were monitored. Rates of valve growth were derived from the slope of the regression equations which related TVALD to the natural logarithm of the body surface area (lnBSA). RESULTS: The children's somatic growth was harmonious throughout the entire follow up period (mean 478 days; range: 171-1,477 days). The TVALD differed significantly at six months and at one and two years after surgery compared to the postoperative value at discharge, rising from 19 mm (range: 15.5-26.0 mm) to 24 mm (range: 19.0-30.0 mm) at the last control examination (p = 0.003), while the related Z-scores remained stable. A significant linear correlation between TVALD and lnBSA was found in 63.6% of patients. The median rate of growth for the whole cohort was 1.96-fold (range: 0.52-5.53-fold) higher than a norm, and correlated strongly and positively with age (r = 0.91; p <0.05). The median postoperative TV insufficiency fraction of 9.8% (range: 0-28.8%) remained constant during the follow up period. The postoperative TV maximal pressure gradient was 5.5 mmHg (range: 3.1-12.2 mmHg), and did not increase over time. CONCLUSION: The implantation of a biodegradable ring does not restrict growth of the native TV annulus; this enabled its stabilization in proportion to the somatic growth in the majority of the children. The TV annulus began to change its dimension at six months postoperatively, which may coincide with its biodegradation. The rate of growth of the TV annulus differed from that in the normal population, and was proportional to the patient age. The increase in TV annulus diameter over time did not have any negative influence on the function of the repaired valve.

Arteriovenous access in hemodialysis: A multidisciplinary perspective for future solutions.

In hemodialysis, vascular access is a key issue. The preferred access is an arteriovenous fistula on the non-dominant lower arm. If the natural vessels are insufficient for such access, the insertion of a synthetic vascular graft between artery and vein is an option to construct an arteriovenous shunt for punctures. In emergency situations and especially in elderly with narrow and atherosclerotic vessels, a cuffed double-lumen catheter is placed in a larger vein for chronic use. The latter option constitutes a greater risk for infections while arteriovenous fistula and arteriovenous shunt can fail due to stenosis, thrombosis, or infections. This review will recapitulate the vast and interdisciplinary scenario that characterizes hemodialysis vascular access creation and function, since adequate access management must be based on knowledge of the state of the art and on future perspectives. We also discuss recent developments to improve arteriovenous fistula creation and patency, the blood compatibility of arteriovenous shunt, needs to avoid infections, and potential development of tissue engineering applications in hemodialysis vascular access. The ultimate goal is to spread more knowledge in a critical area of medicine that is importantly affecting medical costs of renal replacement therapies and patients' quality of life.

Hypothermic Cardiac Arrest - Retrospective cohort study from the International Hypothermia Registry.

AIM: The International Hypothermia Registry (IHR) was created to increase knowledge of accidental hypothermia, particularly to develop evidence-based guidelines and find reliable outcome predictors. The present study compares hypothermic patients with and without cardiac arrest included in the IHR. METHODS: Demographic, pre-hospital and in-hospital data, method of rewarming and outcome data were collected anonymously in the IHR between 2010 and 2020. RESULTS: Two hundred and one non-consecutive cases were included. The major causeof hypothermia was mountain accidents, predominantly in young men. Hypothermic Cardiac Arrest (HCA) occurred in 73 of 201 patients. Core temperature was significantly lower in the patients in cardiac arrest (25.0 vs. 30.0 °C, p < 0.001). One hundred and fifteen patients were rewarmed externally (93% with ROSC), 53 by extra-corporeal life support (ECLS) (40% with ROSC) and 21 with invasive internal techniques (71% with ROSC). The overall survival rate was 95% for patients with preserved circulation and 36% for those in cardiac arrest. Witnessed cardiac arrest and ROSC before rewarming were positive outcome predictors, asphyxia, coagulopathy, high potassium and lactate negative outcome predictors. CONCLUSIONS: This first analysis of 201 IHR patients with moderate to severe accidental hypothermia shows an excellent 95% survival rate for patients with preserved circulation and 36% for HCA patients. Witnessed cardiac arrest, restoration of spontaneous circulation, low potassium and lactate and absence of asphyxia were positive survival predictors despite hypothermia in young, healthy adults after mountaineering accidents. However, accidental hypothermia is a heterogenous entity that should be considered in both treatment strategies and prognostication.

S-nitroso human serum albumin as a nitric oxide donor in drug-eluting vascular grafts: Biofunctionality and preclinical evaluation.

Currently available synthetic small diameter vascular grafts reveal low patency rates due to thrombosis and intimal hyperplasia. Biofunctionalized grafts releasing nitric oxide (NO) in situ may overcome these limitations. In this study, a drug-eluting vascular graft was designed by blending polycaprolactone (PCL) with S-nitroso-human-serum-albumin (S-NO-HSA), a nitric oxide donor with prolonged half-life. PCL-S-NO-HSA grafts and patches were fabricated via electrospinning. The fabrication process was optimized. Patches were characterized in vitro for their morphology, drug release, biomechanics, inflammatory effects, cell proliferation, and expression of adhesion molecules. The selected optimized formulation (8%PCL-S-NO-HSA) had superior mechanical/morphological properties with high protein content revealing extended NO release (for 28 days). 8%PCL-S-NO-HSA patches significantly promoted endothelial cell proliferation while limiting smooth muscle cell proliferation. Expression of adhesion molecules (ICAM-1, VCAM-1) and pro-inflammatory macrophage/cytokine markers (CD80, IL-1α, TNF-α) was significantly reduced. 8%PCL-S-NO-HSA patches had superior immunomodulatory properties by up-regulating anti-inflammatory cytokines (IL-10) and M2 macrophage marker (CD163) at final time points. Grafts were further evaluated in a small rodent model as aortic implants up to 12 weeks. Grafts were assessed by magnetic resonance imaging angiography (MRI) in vivo and after retrieval by histology. All grafts remained 100 % patent with no signs of thrombosis or calcification. 8%PCL-S-NO-HSA vascular grafts supported rapid endothelialization, whereas smooth muscle cell proliferation was hampered in earlier phases. This study indicates that 8%PCL-S-NO-HSA grafts effectively support long-term in situ release of bioactive NO. The beneficial effects observed can be promising features for long-term success of small diameter vascular grafts. STATEMENT OF SIGNIFICANCE: Despite extensive research in the field of small diameter vascular graft replacement, there is still no appropriate substitute to autografts yet. Various limitations are associated with currently available synthetic vascular grafts such as thrombogenicity and intimal hyperplasia. Therefore, developing new generations of such conduits has become a major focus of research. One of the most significant signaling molecules that are involved in homeostasis of the vascular system is nitric oxide. The new designed nitric-oxide eluting vascular grafts described in this study induce rapid surface endothelialization and late migration of SMCs into the graft wall. These beneficial effects have potential to improve current limitations of small diameter vascular grafts.

Paclitaxel-eluting biodegradable synthetic vascular prostheses: a step towards reduction of neointima formation?

BACKGROUND: Clinical small-caliber vascular prostheses are unsatisfactory. Reasons for failure are early thrombosis and late intimal hyperplasia. We thus prepared biodegradable small-caliber vascular prostheses using electrospun polycaprolactone (PCL) with slow-releasing paclitaxel (PTX), an antiproliferative drug. METHODS AND RESULTS: PCL solutions containing PTX were used to prepare nonwoven nanofibre-based 2-mm ID prostheses. Mechanical morphological properties and drug loading, distribution, and release were studied in vitro. Infrarenal abdominal aortic replacement was carried out with nondrug-loaded and drug-loaded prostheses in 18 rats and followed for 6 months. Patency, stenosis, tissue reaction, and drug effect on endothelialization, vascular remodeling, and neointima formation were studied in vivo. In vitro prostheses showed controlled morphology mimicking extracellular matrix with mechanical properties similar to those of native vessels. PTX-loaded grafts with suitable mechanical properties and controlled drug-release were obtained by factorial design. In vivo, both groups showed 100% patency, no stenosis, and no aneurysmal dilatation. Endothelial coverage and cell ingrowth were significantly reduced at 3 weeks and delayed at 12 and 24 weeks in PTX grafts, but as envisioned, neointima formation was significantly reduced in these grafts at 12 weeks and delayed at 6 months. CONCLUSIONS: Biodegradable, electrospun, nanofibre, polycaprolactone prostheses are promising because in vitro they maintain their mechanical properties (regardless of PTX loading), and in vivo show good patency, reendothelialize, and remodel with autologous cells. PTX loading delays endothelialization and cellular ingrowth. Conversely, it reduces neointima formation until the end point of our study and thus may be an interesting option for small caliber vascular grafts.

Dynamic human cadaver model for testing the feasibility of new endovascular techniques and tools.

Endovascular device specifications and technical improvements are strongly required, especially in particular anatomical locations such as the aortic arch and the thoracoabdominal aorta. We present a new technique for total endovascular repair of the aortic arch and an experimental design of a circulation model in the human cadaver in order to evaluate the feasibility of this technique.