scholarly journals Parametric Investigation of an Injection-Jet Self-Powered Fontan Circulation

2021 ◽  
Author(s):  
Ray Prather ◽  
Arka Das ◽  
Michael Farias ◽  
Eduardo Divo ◽  
Alain Kassab ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Oxygen Saturation ◽  
Survival Rates ◽  
Vena Cava ◽  
Blood Rheology ◽  
Design Parameters ◽  
Mortality And Morbidity ◽  
Volume Load ◽  
Tightly Coupled ◽  
Systemic Oxygen

Abstract Rationale: Approximately 1/2500 babies are born with only one functioning ventricle and the Fontan is the third and, ideally final staged palliative operation for these patients. This altered circulation is prone to failure with survival rates below 50% into adulthood in some series. Chronically elevated inferior vena cava (IVC) pressure is implicated as one cause of the mortality and morbidity in this population.Objective: An injection jet shunt (IJS) drawing blood-flow directly from the aortic arch to significantly lower IVC pressure is proposed.Methods and Results: A computer-generated 3D model of a 2–4 year old patient with a fenestrated Fontan and a cardiac output of 2.3L/min was generated. The detailed 3D pulsatile hemodynamics are resolved in a zero-dimensional lumped parameter network tightly-coupled to a 3D computational fluid dynamics model accounting for non-Newtonian blood rheology and resolving turbulence using large eddy simulation. IVC pressure and systemic oxygen saturation were tracked for various IJS-assisted Fontan configurations, altering design parameters such as shunt and fenestration diameters and locations.A baseline “failing” Fontan with 4mm fenestration was tuned to elevated IVC pressure (\(+17.8mmHg\)). Enlargement of the fenestration to 8mm resulted in a 3mmHg IVC pressure drop but an unacceptable reduction in systemic oxygen saturation below 80%. Addition of an IJS with a 2mm nozzle and minor volume load to the ventricle improved the IVC pressure drop to 3.2mmHg while increasing systemic oxygen saturation above 80%.Conclusions: The salutary effects of the IJS to effectively lower IVC pressure while retaining acceptable levels of oxygen saturation are successfully demonstrated.

scholarly journals Cancer treatment associated cardiac toxicities

2018 ◽  
Vol 7 (3) ◽  
pp. 353
Author(s):  
Eric Y. Chang ◽  
Aneese F. Chaudhry ◽  
Victoria Lopez ◽  
Sanjay R. Jain
Keyword(s):  
Cardiovascular Disease ◽  
Cancer Progression ◽  
Superior Vena ◽  
Survival Rates ◽  
Vena Cava ◽  
Cancer Therapeutics ◽  
Developed Countries ◽  
Cardiovascular Complications ◽  
Mortality And Morbidity ◽  
Vena Cava Syndrome

Cardiovascular disease remains the leading cause of mortality and morbidity in men and women both in the US and worldwide. With increased access to healthcare, it is predicted that life expectancies in developed countries will continue to rise and thus, lead to an increase in both cardiovascular disease and cancer. Similarly, improved survival rates in cancer patients have led to an increased awareness of the presence and potential worsening of cardiovascular disease in these patients. Cardiovascular complications due to side effects from cancer therapy or from cancer progression can be a common occurrence. Although recent advances in cancer therapeutics have led to improved survival rates and quality of life, the increase in life expectancy may be counteracted by the increased morbidity and mortality from progressive cardiac pathology. Examples of such complications include local invasion or distant metastatic spread, which can lead to superior vena cava syndrome, cardiac tamponade, or hyperviscosity syndromes. In addition, many chemo and radiation therapies can be directly toxic to the cardiovascular system. This review aims to discuss the potential cardiac toxicities of the most commonly used chemotherapeutics along with some strategies to manage these complex patients.

scholarly journals Evaluation of Optimization of Pulmonary and Systemic Blood Flow in Children after Bidirectional Cavapulmonary Anastomosis

2021 ◽  
pp. 57-62
Author(s):  
Ivan V. Dziuryi ◽  
Iaroslav P. Truba ◽  
Liliya M. Prokopovych ◽  
Vasyl V. Fylypchuk ◽  
Vasyl V. Lazoryshynets
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Flow Ratio ◽  
Systemic Blood ◽  
Systemic Blood Flow ◽  
Blood Flow Ratio ◽  
Systemic Oxygen

In patients after bidirectional cavapulmonary anastomosis, blood flow through the superior vena cava (SVC), providing effective pulmonary blood flow, is the most important factor influencing blood oxygen saturation. Blood flow through the inferior vena cava recirculates into the systemic bloodstream. The study of the ratio of these flows will provide better understanding of the physiology of blood circulation after anastomosis and determine systemic oxygen saturation of blood and optimal time to perform surgery.   The aim. To determine volumetric blood flow in the SVC, calculate pulmonary to systemic blood flow ratio in children after bidirectional cavapulmonary anastomosis, and evaluate its contribution to cardiac output and oxygen saturation in systemic blood flow. Materials and methods. In the period from January 2010 to June 2021, 51 patients with congenital heart defects with depleted pulmonary blood flow underwent hemodynamic correction at the National Amosov Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine. There were 29 male patients (57%) and 22 female patients (43%). The mean age of the patients at the time of the surgery was 34 ± 18.2 months (2 to 120 months), the mean age of patients at the time of examination was 43.5 ± 28.4 months (12 to 134 months). The main method of diagnosis in determining the defect and assessing the immediate and long-term results was echocardiographic examination and probing of the heart cavities. To evaluate the optimization of pulmonary/systemic blood flow we used equations obtained using the Fick method. Pulmonary to systemic blood flow ratio was calculated separately for 35 patients. Among the examined 35 patients, 18 children were older than 2.5 years, so all the examined patients were conveniently divided into 2 age groups: I group (n = 17) up to 2.5 years, II group (n = 18) older than 2.5 years to assess the contribution of SVC to the systemic circulation depending on age. Results. Pulmonary to systemic blood flow ratio was calculated for 35 patients Qp/Qs = (82% – 66%) / (97% – 66%) = 0.52. The calculated cardiac index according to echocardiography was 4.0 ± 0.85 L/min/m2 which corresponds to the SVC saturation (r = 0.60, p = <0.001). The flow in the superior vena cava = 2.08 L/min/m2. There was a very interesting trend towards decrease in the average rate of systemic saturation in patients after bidirectional cavapulmonary anastomosis depending on age and duration of surgery. Thus, in 17 patients of group I, the calculated Qp/Qs was (84% – 67%) / (97% – 67%) = 0.57. In patients of group II, the average systemic oxygen saturation was 78 ± 2% (from 65% to 81%). Calculated Qp/Qs for 18 patients of group II = (78% – 66%) / (97% – 66%) = 0.39, which indicates a decrease in pulmonary to systemic ratio with the growth of the child. Decreased systemic saturation after bidirectional cavapulmonary anastomosis in patients with increasing age and body surface area is associated with a decrease in the proportional flow from the superior vena cava. Therefore, in our clinical material, we confirmed the phenomenon of change in pulmonary to systemic ratio depending on age, which was described by Salim et al. according to a study conducted on healthy babies. Conclusions. The contribution of SVC flow to total cardiac output after bidirectional cavapulmonary anastomosis is directly associated with the patient’s age and gradually decreases in older patients, as indicated by a decrease in systemic saturation, so the clinical effect of bidirectional cavapulmonary anastomosis may be significantly better when performing surgery in early childhood.

scholarly journals Clogging sensitivity of flow distributors designed for radially elongated hexagonal pillar array columns: a computational modelling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Farideh Haghighi ◽  
Zahra Talebpour ◽  
Amir Sanati-Nezhad
Keyword(s):  
Pressure Drop ◽  
Aspect Ratio ◽  
Contact Zone ◽  
Separation Efficiency ◽  
Fluid Dynamic ◽  
Computational Modelling ◽  
Channel Width ◽  
Fluid Distribution ◽  
Design Parameters ◽  
Pillar Array

AbstractFlow distributor located at the beginning of the micromachined pillar array column (PAC) has significant roles in uniform distribution of flow through separation channels and thus separation efficiency. Chip manufacturing artifacts, contaminated solvents, and complex matrix of samples may contribute to clogging of the microfabricated channels, affect the distribution of the sample, and alter the performance of both natural and engineered systems. An even fluid distribution must be achieved cross-sectionally through careful design of flow distributors and minimizing the sensitivity to clogging in order to reach satisfactory separation efficiency. Given the difficulty to investigate experimentally a high number of clogging conditions and geometries, this work exploits a computational fluid dynamic model to investigate the effect of various design parameters on the performance of flow distributors in equally spreading the flow along the separation channels in the presence of different degrees of clogging. An array of radially elongated hexagonal pillars was selected for the separation channel (column). The design parameters include channel width, distributor width, aspect ratio of the pillars, and number of contact zone rows. The performance of known flow distributors, including bifurcating (BF), radially interconnected (RI), and recently introduced mixed-mode (MMI) in addition to two new distributors designed in this work (MMII and MMIII) were investigated in terms of mean elution time, volumetric variance, asymmetry factors, and pressure drop between the inlet and the monitor line for each design. The results show that except for pressure drop, the channel width and aspect ratio of the pillars has no significant influence on flow distribution pattern in non-clogged distributors. However, the behavior of flow distributors in response to clogging was found to be dependent on width of the channels. Also increasing the distributor width and number of contact zone rows after the first splitting stage showed no improvement in the ability to alleviate the clogging. MMI distributor with the channel width of 3 µm, aspect ratio of the pillars equal to 20, number of exits of 8, and number of contact zones of 3 exhibited the highest stability and minimum sensitivity to different degrees of clogging.

Bifurcated bypass in severe chronic limb threatening ischaemia

Vascular ◽  
2021 ◽  
pp. 170853812199985
Author(s):  
Daniele Adami ◽  
Michele Marconi ◽  
Alberto Piaggesi ◽  
Davide M Mocellin ◽  
Raffaella N Berchiolli ◽  
...  
Keyword(s):  
Survival Rates ◽  
Primary Patency ◽  
Free Survival ◽  
Mortality And Morbidity ◽  
Bypass Patency ◽  
Stage 4 ◽  
Endovascular Approach ◽  
The Mean ◽  
Clinical Records

Objectives Revascularization according to the angiosome concept is of proven importance for limb salvage in chronic limb threatening ischaemia but it is not always practicable. Bifurcated bypasses could be considered as an option when an endovascular approach is not feasible or has already failed and a single bypass would not allow direct revascularization of the ischaemic area. Bifurcated bypasses are characterized by landing on two different arteries, the main artery (in direct continuity with the foot vessels) and the secondary one (perfusing the angiosome district). The aim of this study is to evaluate the safety and effectiveness of bifurcated bypass in chronic limb threatening ischaemia. Methods Thirty-five patients were consecutively treated with a bifurcated bypass for chronic limb threatening ischaemia from January 2014 to December 2019 in a single vascular surgery centre. Data from clinical records and operative registers were collected prospectively in an electronic database and retrospectively analysed. Primary and primary assisted bypass patency, amputation-free survival, morbidity and mortality rates at 12 and 24 months were analysed. Results Mean follow-up period was 25.1 months (range 2–72 months). Thirty-six bifurcated bypasses were performed on 35 patients (age 75.3 ± 7.2 years; 69.4% were male). According to Wound, Ischemia, foot Infection classification 22.2% belonged to stage 3 and 77.8% to stage 4 and the mean Rutherford’s class was 5.1 ± 0.7. Immediate technical success was 100%. Early mortality and morbidity rates were respectively 5.5%, and 33.3%; foot surgery was performed in 50% of cases with wound healing in all patients. Primary patency and primary assisted bypass patency were 96.7% and 100% at 6 months; 85.2% and 92% at 12 months, 59.9% and 73.4% at 24 months, respectively. Amputation-free survival at 12 and 24 months was, respectively, 95.6% and 78.8%. Overall survival rates at 12 and 24 months were respectively 94.4% and 91.6%. Conclusions Bifurcates bypass can provide good results in patients with chronic limb threatening ischaemia without endovascular option, especially in diabetic ones. Bifurcated bypass is a complex surgical solution, both to be planned and performed, and it is quite invasive for frail patients that should be accurately selected.

Pulse oximetry: a diagnostic instrument in pulpal vitality testing

2003 ◽  
Vol 26 (2) ◽  
pp. 141-145 ◽  
Author(s):  
A. Munshi ◽  
Amitha Hegde ◽  
Sangeeth Radhakrishnan
Keyword(s):  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Index Finger ◽  
Control Population ◽  
Diagnostic Instrument ◽  
Base Line ◽  
Clinical Value ◽  
Electrical Test ◽  
Anterior Teeth ◽  
Systemic Oxygen

One hundred children with normal maxillary central and lateral incisors were subjected to vitality tests each by electrical and pulse oximetry. As a control population to confirm the readings, 10 known nonvital anterior teeth with complete endodontic fillings were tested. The systemic oxygen saturation values measured on the index finger of the patient served as the control for the comparison of the oxygen saturation values measure on the teeth. The SaO2 values obtained on the teeth were correlated with the electrical test readings. The correlation between the SaO2 readings and electrical testing readings were found to be negative i.e. as the values of the electrical pulp testing reading increased, the SaO2 values decreased. Since a reproducible SaO2 level is obtainable on the vital teeth, pulse oximetry has immediate clinical value in providing base line vitality data for the traumatised teeth.

scholarly journals Preoperative Cerebral Oxygen Saturation and Clinical Outcomes in Cardiac Surgery

2011 ◽  
Vol 114 (1) ◽  
pp. 58-69 ◽  
Author(s):  
Matthias Heringlake ◽  
Christof Garbers ◽  
Jan-Hendrik Käbler ◽  
Ingrid Anderson ◽  
Hermann Heinze ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Oxygen Saturation ◽  
Clinical Outcomes ◽  
Natriuretic Peptide ◽  
Troponin T ◽  
Area Under The Curve ◽  
Cerebral Oxygen Saturation ◽  
Cerebral Oxygen ◽  
Mortality And Morbidity ◽  
High Sensitive Troponin

Background The current study was designed to determine the relation between preoperative cerebral oxygen saturation (Sco2), variables of cardiopulmonary function, mortality, and morbidity in a heterogeneous cohort of cardiac surgery patients. Methods In this study, 1,178 consecutive patients scheduled for on-pump surgery were prospectively studied. Preoperative Sco2, demographics, N-terminal pro-B-type natriuretic peptide, high-sensitive troponin T, clinical outcomes, and 30-day and 1-yr mortality were recorded. Results Median additive EuroSCORE was 5 (range: 0-19). Thirty-day and 1-yr mortality and major morbidity (at least two major complications and/or a high-dependency unit stay of at least 10 days) were 3.5%, 7.7%, and 13.3%, respectively. Median minimal preoperative oxygen supplemented Sco2 (Sco2min-ox) was 64% (range: 15-92%). Sco2min-ox was correlated (all: P value &lt;0.0001) with N-terminal pro-B-type natriuretic peptide (ρ: -0.35), high-sensitive troponin T (ρ: -0.28), hematocrit (ρ: 0.34), glomerular filtration rate (ρ: 0.19), EuroSCORE (τ: 0.20), and left ventricular ejection fraction class (τ: 0.12). Thirty-day nonsurvivors had a lower Sco2min-ox than survivors (median 58% [95% CI, 50.7-62%] vs. 64% [95% CI, 64-65%]; P &lt; 0.0001). Receiver-operating curve analysis of Sco2min-ox and 30-day mortality revealed an area-under-the-curve of 0.71 (95% CI, 0.68-0.73%; P &lt; 0.0001) in the total cohort and an area-under-the-curve of 0.77 (95% CI, 0.69-0.86%; P &lt; 0.0001) in patients with a EuroSCORE more than 10. Logistic regression based on different EuroSCORE categories (0-2; 3-5, 6-10, &gt;10), Sco2min-ox, and duration of cardiopulmonary bypass showed that a Sco2min-ox equal or less than 50% is an independent risk factor for 30-day and 1-yr mortality. Conclusions Preoperative Sco2 levels are reflective of the severity of cardiopulmonary dysfunction, associated with short- and long-term mortality and morbidity, and may add to preoperative risk stratification in patients undergoing cardiac surgery.

scholarly journals The Clinical Outcome in Patients with Peritoneal Metastasis

2020 ◽  
pp. 1-3
Author(s):  
Spiliotis J ◽  
◽  
Farmakis D ◽  
Raptis A ◽  
Kopanakis N ◽  
...  
Keyword(s):  
Systemic Chemotherapy ◽  
Treatment Options ◽  
Survival Rates ◽  
Peritoneal Metastases ◽  
Mortality And Morbidity ◽  
Chemotherapy Group ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Group D

Cytroreductive surgery (CRS) and HIPEC are controversial effective treatment options for selected patients with peritoneal metastases. We retrospectively examined 4.500 patients with peritoneal metastases from different tumors from 2005 to 2020. Patients were divided in 4 groups, surgery plus HIPEC and then systemic chemotherapy: Group A n=730, Group B n=700, R0 surgery plus systemic chemotherapy, Group C n=870, palliative surgery plus systemic chemotherapy and Group D n=2.200, palliative care and best support. The postoperative outcomes, morbidity, mortality were compared between the 4 groups. The mean survival rates Group A=24,4+10,2m, Group B= 18,4+6,3m, Group C=12,3+5,7m, Group D=5,8+2,3m (p<0.05 between Gr A vr Gr B). There was no statistically significant difference in the 30-day mortality and morbidity. In conclusion CRS + HIPEC are feasible in 16% of our patients with peritoneal metastases and are associated with pro-longed survival.

Localization of intrahepatic portal vascular resistance

1986 ◽  
Vol 251 (3) ◽  
pp. G375-G381 ◽  
Author(s):  
W. W. Lautt ◽  
C. V. Greenway ◽  
D. J. Legare ◽  
H. Weisman
Keyword(s):  
Pressure Drop ◽  
Portal Vein ◽  
Vascular Resistance ◽  
Venous Pressure ◽  
Vena Cava ◽  
Sympathetic Nerves ◽  
Hepatic Veins ◽  
Pressure Changes ◽  
Stimulation Of ◽  
Anesthetized Cat

The pressure drop from the portal vein to the vena cava occurs primarily across a postsinusoidal site localized to a narrow segment (less than 0.5 cm) of hepatic veins (roughly 1.5 mm diam) in the anesthetized cat. Portal venous pressure (PVP = 8.9 +/- 0.3 mmHg) and lobar hepatic venous pressure (LVP = 8.7 +/- 0.4 mmHg) are insignificantly different, and pressure changes imposed from the presinusoidal or postsinusoidal side are equally transmitted to both pressure sites. Several types of experiments were done to validate the LVP measurement. The portal vein, hepatic sinusoids, and hepatic veins proximal to the resistance site are all under a similar pressure. Previously reported calculations of hepatic vascular resistance are in error because of incorrect assumptions of sinusoidal pressure and localization of the portal resistance site as presinusoidal. Stimulation of hepatic sympathetic nerves for 3 min caused LVP and PVP to increase equally, showing that the increased "portal" resistance is postsinusoidal across the same region of the hepatic veins that was previously localized as the site of resistance in the basal state.

scholarly journals Central Venous Oxygenation for Mixed Venous Oxygen Saturation

2018 ◽  
Vol 02 (02) ◽  
pp. 057-060
Author(s):  
Naresh Kumar Agarwal ◽  
Arun Subramanian
Keyword(s):  
Oxygen Saturation ◽  
Superior Vena ◽  
Vena Cava ◽  
Clinical Decision ◽  
Mixed Venous Oxygen Saturation ◽  
The Body ◽  
Wide Range ◽  
Venous Oxygen Saturation ◽  
Range Of Values ◽  
Mixed Venous

AbstractVenous oxygen saturation has been traditionally used as a marker for tissue hypoxia. A wide range of factors can affect it. Literature abounds with articles on the use of the same in decision making and clinical management of patients in shock. Likewise, the application of venous saturation in patients undergoing cardiac and noncardiac surgery has been demonstrated. The controversy as to whether superior vena cava oxygen saturation can replace the traditional mixed venous oxygen saturation is never ending. Irrespective of the body of evidence, it is recommended that clinical decision should not be based on a single value, and a range of values needs to be incorporated to differentiate a critically ill from a noncritically ill patient.

Pharmacological treatment of hepatocellular carcinoma with cavoatrial tumor thrombus – case series and literature review

2019 ◽  
Vol 57 (04) ◽  
pp. 501-507 ◽  
Author(s):  
Tianzuo Zhan ◽  
Janina Sollors ◽  
Niels Steinebrunner ◽  
Hans Schlitt ◽  
Christian Stroszczynski ◽  
...  
Keyword(s):  
Tumor Thrombus ◽  
Systemic Treatment ◽  
Treatment Options ◽  
Survival Rates ◽  
Vena Cava ◽  
Case Series ◽  
Surgical Approaches ◽  
Surgical Interventions ◽  
Advanced Hcc ◽  
Multimodal Therapy Concept

AbstractHepatocellular carcinomas (HCC) that extend into the vena cava and the right atrium have a poor prognosis. Surgical approaches including partial hepatectomy and thrombectomy are the most frequently reported treatment options. However, most patients with advanced HCC are not eligible for complex surgical interventions due to reduced liver function, comorbidities, and metastases. At the same time, systemic treatment options of HCC have expanded in recent years. Here, we report 3 cases of patients with advanced HCC who developed a cavoatrial tumor thrombus (CATT) after initial surgical or interventional therapy. The patients were consequently treated with sorafenib or nivolumab. In all cases, the tumor responded to systemic treatment with disease stabilization or partial regression. Overall survival after diagnosis of CATT was 3 and 17 months for sorafenib and 7 + months for nivolumab. Compared to survival rates of alternative treatment options, systemic therapies demonstrated comparable outcomes. In summary, pharmacotherapy is an efficient and well worth option to treat patients with HCC and CATT and should be an integral part of a multimodal therapy concept.

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