robotized-testing-camera-positions-to-determine-ideal-configuration

Robotized Testing of Camera Positions to Determine Ideal Configuration for Stereo 3D Visualization of Open-Heart Surgery

Stereo 3D video from surgical procedures can be highly valuable for medical education and improve clinical communication. But access to the operating room ...

Skåne University Hospital

Perlecan is a proteoglycan composed of a 470-kDa core protein linked to three heparan sulfate (HS) glycosaminoglycan chains. The intact proteoglycan inhibits the smooth muscle cell (SMC) response to vascular injury. Hspg2(Δ3/Δ3) (MΔ3/Δ3) mice produce a mutant perlecan lacking the HS side chains. The objective of this study was to determine differences between these two types of perlecan in modifying SMC activities to the arterial injury response, in order to define the specific role of the HS side chains. In vitro proliferative and migratory activities were compared in SMC isolated from MΔ3/Δ3 and wild-type mice. Proliferation of MΔ3/Δ3 SMC was 1.5× greater than in wild type (P < 0.001), increased by addition of growth factors, and showed a 42% greater migratory response than wild-type cells to PDGF-BB (P < 0.001). In MΔ3/Δ3 SMC adhesion to fibronectin, and collagen types I and IV was significantly greater than wild type. Addition of DRL-12582, an inducer of perlecan expression, decreased proliferation and migratory response to PDGF-BB stimulation in wild-type SMC compared with MΔ3/Δ3. In an in vivo carotid artery wire injury model, the medial thickness, medial area/lumen ratio, and macrophage infiltration were significantly increased in the MΔ3/Δ3 mice, indicating a prominent role of the HS side chain in limiting vascular injury response. Mutant perlecan that lacks HS side chains had a marked reduction in the inhibition of in vitro SMC function and the in vivo arterial response to injury, indicating the critical role of HS side chains in perlecan function in the vessel wall. 

Heparan sulfate side chains have a critical role in the inhibitory effects of perlecan on vascular smooth muscle cell response to arterial injury.

Crowding of the mediastinum after complex cardiac repair procedures in neonates and young children is a frequent problem. To create space, the sternal wound is kept open, commonly with a plastic stent, for later closure. Despite this maneuver, space is still an issue, and appropriate placement of the mediastinal drain can become a challenge. In this article we describe a simple and effective way to eliminate the problem. Holes are made in the sternal stent, and the drain is pulled through these holes. The drain is elevated away from the heart surface and does not contribute to the crowding. 

Smart placement of a mediastinal drain in a neonate who requires a postoperative open sternum.

Successful enlargement of the small aortic root in children has remained a management challenge, particularly in the neonates and small infants. Achieving this aim requires thorough understanding of the anatomic features of the left ventricular outflow tract, careful patient selection, and skilful execution of complex surgery. This article reviews the anatomical principles upon which the surgical techniques rely, the decision-making, the timing of surgery, the surgical options, and the outcomes. 

When and How to Enlarge the Small Aortic Root.

The support of the pulmonary autograft root by the fibromuscular left ventricular outflow tract is emphasized to address the concern related to the dilatation of the pulmonary autograft structures in the paediatric population.

Midterm results of the Ross procedure in children: an appraisal of the subannular implantation with interrupted sutures technique.

In children with single ventricle physiology, increased pulmonary vascular resistance may impede surgical progression or result in failing single ventricle physiology. The use of pulmonary vasodilators has been suggested as a potential therapy. However, knowledge on indication, dosage, and effect is limited. A retrospective case notes review of all (n = 36) children with single ventricle physiology, treated with pulmonary vasodilators by the UK Pulmonary Hypertension Service for Children 2004-2017. Therapy was initiated in Stage 1 (n = 12), Glenn (n = 8), or TCPC (n = 16). Treatment indications were high mean pulmonary arterial pressure, cyanosis, reduced exercise tolerance, protein-losing enteropathy, ascites, or plastic bronchitis. Average dose of sildenafil was 2.0 mg/kg/day and bosentan was 3.3 mg/kg/day. 56% had combination therapy. Therapy was associated with a reduction of the mean pulmonary arterial pressure from 19 to 14 mmHg (n = 17, p < 0.01). Initial therapy with one or two vasodilators was associated with an increase in the mean saturation from 80 to 85%, (n = 16, p < 0.01). Adding a second vasodilator did not give significant additional effect. 5 of 12 patients progressed from Stage 1 to Glenn, Kawashima, or TCPC, and 2 of 8 from Glenn to TCPC during a mean follow-up time of 4.7 years (0-12.8). Bosentan was discontinued in 57% and sildenafil in 14% of treated patients and saturations remained stable. Pulmonary vasodilator therapy was well tolerated and associated with improvements in saturation and mean pulmonary arterial pressure in children with single ventricle physiology. It appears safe to discontinue when no clear benefit is observed.

Pulmonary Vasodilator Therapy in Children with Single Ventricle Physiology: Effects on Saturation and Pulmonary Arterial Pressure.

In pulmonary arterial hypertension, plexiform lesions are associated with severe arterial obstruction and right ventricular failure. Exploring their structure and position is crucial for understanding the interplay between hemodynamics and vascular remodeling. The aim of this research was to use synchrotron-based phase-contrast micro-CT to study the three-dimensional structure of plexiform lesions. Archived paraffin-embedded tissue samples from 14 patients with pulmonary arterial hypertension (13 idiopathic, 1 with known -mutation) were imaged. Clinical data showed high-median PVR (12.5 WU) and mPAP (68 mmHg). Vascular lesions with more than 1 lumen were defined as plexiform. Prior radiopaque dye injection in some samples facilitated 3-D rendering. Four distinct types of plexiform lesions were identified: ) localized within or derived from monopodial branches (supernumerary arteries), often with a connection to the vasa vasorum; ) localized between pulmonary arteries and larger airways as a tortuous transformation of intrapulmonary bronchopulmonary anastomoses; ) as spherical structures at unexpected abrupt ends of distal pulmonary arteries; and ) as occluded pulmonary arteries with recanalization. By appearance and localization, types 1-2 potentially relieve pressure via the bronchial circulation, as pulmonary arteries in these patients were almost invariably occluded distally. In addition, types 1-3 were often surrounded by dilated thin-walled vessels, often connected to pulmonary veins, peribronchial vessels, or the vasa vasorum. Collaterals, bypassing completely occluded pulmonary arteries, were also observed to originate within plexiform lesions. In conclusion, synchrotron-based imaging revealed significant plexiform lesion heterogeneity, resulting in a novel classification. The four types likely have different effects on hemodynamics and disease progression.

Article	Year
Heparan sulfate side chains have a critical role in the inhibitory effects of perlecan on vascular smooth muscle cell response to arterial injury. American journal of physiology. Heart and circulatory physiology\| PubMed ID: 24858854	2014
Smart placement of a mediastinal drain in a neonate who requires a postoperative open sternum. The Annals of thoracic surgery\| PubMed ID: 24882318	2014
When and How to Enlarge the Small Aortic Root. Seminars in thoracic and cardiovascular surgery. Pediatric cardiac surgery annual\| PubMed ID: 27060044	2016
Midterm results of the Ross procedure in children: an appraisal of the subannular implantation with interrupted sutures technique. European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery\| PubMed ID: 28459959	2017
Pulmonary Vasodilator Therapy in Children with Single Ventricle Physiology: Effects on Saturation and Pulmonary Arterial Pressure. Pediatric cardiology\| PubMed ID: 32734529	2020
Distinct types of plexiform lesions identified by synchrotron-based phase-contrast micro-CT. American journal of physiology. Lung cellular and molecular physiology\| PubMed ID: 33881927	2021

Phan-Kiet Tran

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