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1.
BMC Pregnancy Childbirth ; 24(1): 228, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38566074

ABSTRACT

BACKGROUND: Placenta accreta spectrum disorders (PASDs) increase the mortality rate for mothers and newborns over a decade. Thus, the purpose of the study is to evaluate the neonatal outcomes in emergency cesarean section (CS) and planned surgery as well as in Cesarean hysterectomy and the modified one-step conservative uterine surgery (MOSCUS). The secondary aim is to reveal the factors relating to poor neonatal outcomes. METHODS: This was a single-center retrospective study conducted between 2019 and 2020 at Tu Du Hospital, in the southern region of Vietnam. A total of 497 pregnant women involved in PASDs beyond 28 weeks of gestation were enrolled. The clinical outcomes concerning gestational age, birth weight, APGAR score, neonatal intervention, neonatal intensive care unit (NICU) admission, and NICU length of stay (LOS) were compared between emergency and planned surgery, between the Cesarean hysterectomy and the MOSCUS. The univariate and multivariable logistic regression were used to assess the adverse neonatal outcomes. RESULTS: Among 468 intraoperatively diagnosed PASD cases who underwent CS under general anesthesia, neonatal outcomes in the emergency CS (n = 65) were significantly poorer than in planned delivery (n = 403). Emergency CS increased the odds ratio (OR) for earlier gestational age, lower birthweight, lower APGAR score at 5 min, higher rate of neonatal intervention, NICU admission, and longer NICU LOS ≥ 7 days with OR, 95% confidence interval (CI) were 10.743 (5.675-20.338), 3.823 (2.197-6.651), 5.215 (2.277-11.942), 2.256 (1.318-3.861), 2.177 (1.262-3.756), 3.613 (2.052-6.363), and 2.298 (1.140-4.630), respectively, p < 0.05. Conversely, there was no statistically significant difference between the neonatal outcomes in Cesarean hysterectomy (n = 79) and the MOSCUS method (n = 217). Using the multivariable logistic regression, factors independently associated with the 5-min-APGAR score of less than 7 points were time duration from the skin incision to fetal delivery (min) and gestational age (week). One minute-decreased time duration from skin incision to fetal delivery contributed to reduce the risk of adverse neonatal outcome by 2.2% with adjusted OR, 95% CI: 0.978 (0.962-0.993), p = 0.006. Meanwhile, one week-decreased gestational age increased approximately two fold odds of the adverse neonatal outcome with adjusted OR, 95% CI: 1.983 (1.600-2.456), p < 0.0001. CONCLUSIONS: Among pregnancies with PASDs, the neonatal outcomes are worse in the emergency group compared to planned group of cesarean section. Additionally, the neonatal comorbidities in the conservative surgery using the MOSCUS method are similar to Cesarean hysterectomy. Time duration from the skin incision to fetal delivery and gestational age may be considered in PASD surgery. Further data is required to strengthen these findings.


Subject(s)
Cesarean Section , Placenta Accreta , Pregnancy , Infant, Newborn , Female , Humans , Cesarean Section/adverse effects , Retrospective Studies , Vietnam/epidemiology , Placenta Accreta/surgery , Placenta Accreta/etiology , Birth Weight
2.
Int J Public Health ; 69: 1606941, 2024.
Article in English | MEDLINE | ID: mdl-38651035

ABSTRACT

Objectives: We tested an adapted version of an effective U.S.-based peer-texting intervention to promote Quitline use and smoking cessation among rural participants in Vietnam. Methods: We conducted a two-arm randomized trial with participants recruited at four rural community centers. The intervention included peer messages sent for six months that promoted Quitline use and smoking cessation. Additionally, biweekly two-way text messages assessed participants' interest in Quitline referral and current smoking status. Comparison participants received only the bi-weekly text message assessment of their current smoking status. At six months, we assessed Quitline use and smoking cessation. Smoking cessation was assessed using the 7-day point prevalence question and verified with a carbon monoxide breath monitor (<=6 ppm). Results: Among 750 participants, the intervention had higher Quitline verified use (18%, 95% CI 0.14, 0.22) than comparison (1%, 95% CI .2, 2, p < 0.0001). Carbon-monoxide-verified smoking cessation did not differ between the two groups. However, intervention (28.3%, 95% CI) and comparison (28.1%, 95% CI) participants had substantial rates of carbon monoxide cessation at 6 months (both 28%). Conclusion: Our study highlighted the promise of texting interventions to extend tobacco control efforts in Vietnam.


Subject(s)
Rural Population , Smoking Cessation , Text Messaging , Humans , Smoking Cessation/methods , Vietnam , Male , Female , Adult , Middle Aged , Peer Group , Health Promotion/methods , Hotlines
3.
Int J Emerg Med ; 17(1): 14, 2024 Jan 29.
Article in English | MEDLINE | ID: mdl-38287235

ABSTRACT

BACKGROUND: Cardiopulmonary collapse is a catastrophic event in cesarean section, which leads to adverse outcomes for both the mother and the fetus. Pulmonary embolism is one of the rare etiologies of this entity. We herein reported the successful management of acute embolism pulmonary associated with cesarean delivery on a healthy pregnant woman at our tertiary referral hospital. CASE PRESENTATION: A full-term pregnant woman hospitalized for planned cesarean delivery due to placenta previa without cardiorespiratory diseases. She was scheduled uneventfully for a planned cesarean section. After placental delivery, the patient spontaneously fell into cardiopulmonary collapse and her vital signs deteriorated rapidly. The obstetricians promptly completed the cesarean section and performed all procedures to prevent the PPH and preserve the uterus. At the same time, the anesthesiologists continued to carry out advanced heart-lung resuscitation in order to control her vital signs. After surgery, the multidisciplinary team assessed the patient and found a thrombus in her pulmonary circulation. Therefore, the patient was managed with therapeutic anticoagulation. The patient recovered in good clinical condition and was discharged after 2 weeks without any complications. CONCLUSIONS: The diagnosis of acute pulmonary embolism is extremely difficult due to uncommon occurrence, sudden onset, and non-specific presentation. Awareness of this life-threatening pathology during cesarean delivery should be raised. Interdisciplinary assessment must be essentially established in this life-threatening condition. After the whole conventional management, uterine conservation may be acceptable where applicable. Further data is required to encourage this finding.

4.
Int J Gynaecol Obstet ; 165(2): 723-736, 2024 May.
Article in English | MEDLINE | ID: mdl-38009657

ABSTRACT

OBJECTIVES: To compare maternal outcome measures in surgical management of placenta accreta spectrum (PAS)-the modified one-step conservative uterine surgery (MOSCUS), a new approach at Tu Du Hospital in Vietnam, versus cesarean hysterectomy, and to identify factors that appear to contribute to the successful outcome of the MOSCUS. METHODS: This retrospective study was conducted at Tu Du Hospital in southern Vietnam between January 2019 and December 2020. The study enrolled all pregnant women at more than 28 weeks of pregnancy with a diagnosis of PAS who underwent either a cesarean hysterectomy or a uterus-preserving approach using the MOSCUS method. RESULTS: The prevalence of PAS at our single tertiary referral hospital was 0.4% (619 PAS cases/132 518 births) in 2 years. Among 296 patients, the surgical time duration, estimated blood loss, and red blood cell transfusion in the MOSCUS group (n = 217) were all significantly less than in the cesarean hysterectomy group (n = 79) (152.72 ± 42.23 vs 185.13 ± 58.22 min, 1000 vs 1500 mL, and 500 vs 710 mL, respectively). Intraoperatively, the rate of visceral injuries in the hysterectomy group was higher than that in the MOSCUS group (P < 0.001). However, the rate of postoperative infection was higher in the MOSCUS group than in the cesarean hysterectomy group (P = 0.012). Of a total of 217 cases managed using the MOSCUS management, 24 required a secondary hysterectomy; the success rate was 88.9% (95% confidence interval [CI] 84.3%-93.1%). Some of the primary factors associated with the success of MOSCUS included maternal age less than 35 years, planned surgery, severity of PAS, and estimated blood loss during surgery (odds ratio [OR] 5.16, 95% CI 1.96-13.59; OR 3.05, 95% CI 1.08-8.62; OR 3.62, 95% CI 1.19-10.98; and OR 49.66, 95% CI 11.16-221.02, respectively; P < 0.05). CONCLUSION: MOSCUS is an acceptable alternative to cesarean hysterectomy in many patients diagnosed with PAS. This new surgical management of PAS resulted in the preservation of the uterus, and a favorable outcome in nearly 9 out of 10 pregnant women. We believe that MOSCUS can be safely offered for the management of PAS in referral hospital settings.


Subject(s)
Placenta Accreta , Placenta Previa , Female , Humans , Pregnancy , Adult , Retrospective Studies , Pregnant Women , Vietnam , Placenta Accreta/diagnosis , Hysterectomy/methods , Placenta Previa/surgery
8.
J Obstet Gynaecol Res ; 49(7): 1750-1761, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37245054

ABSTRACT

AIMS: The study purposed to evaluate the success rate of cervical ripening using dinoprostone controlled-release vaginal insert and reveal some factors relating to successful cervical ripening. METHODS: This cross-sectional study was conducted at Tu Du Hospital in Vietnam from December 2021 to August 2022. The study enrolled 200 pregnant women with gestational age ≥37 weeks diagnosed with oligohydramnios. These candidates underwent dinoprostone cervical ripening (DCR) according to the local protocol. The Bishop score ≥7 after 24 h was determined for the successful cervical ripening (SCR). RESULTS: In total, the success rate of DCR achieved at 57.5% and the cesarean delivery rate was 46.5%. None of the severe side-effects and complications was present. Using multivariable logistic regression, the study found that the body mass index ≥25 kg/m2 and oxytocin infusion drip related to SCR with adjusted odds ratio (aOR): 3.67 (95% confidence intervals [CI]: 1.78-7.57) and aOR: 4.68 (95% CI: 1.84-11.93), p < 0.001. Using the Kaplan-Meier curve, the present study revealed a significant difference between Bishop <3 and ≥3 following the duration time of cervical ripening, with hazard ratio: 1.38 (95% CI: 1.19-1.59), p < 0.001. The time duration of cervical ripening was not significantly different following amniotic fluid index from 3 to 5 cm. CONCLUSIONS: Cervical ripening using a dinoprostone vaginal insert is a potentially acceptable method in term pregnancy accompanying with oligohydramnios. The probability of SCR can be predicted on a careful assessment of relative factors by obstetricians. Further studies are required to strengthen these findings.


Subject(s)
Cervical Ripening , Oligohydramnios , Oxytocics , Female , Humans , Infant , Pregnancy , Administration, Intravaginal , Cervical Ripening/drug effects , Cross-Sectional Studies , Dinoprostone/administration & dosage , Dinoprostone/pharmacology , Labor, Induced/methods , Oxytocics/administration & dosage , Oxytocics/pharmacology , Delayed-Action Preparations
9.
Int J Emerg Med ; 16(1): 26, 2023 Apr 17.
Article in English | MEDLINE | ID: mdl-37069520

ABSTRACT

BACKGROUND: Spontaneous hemoperitoneum in pregnancy (SHiP) refers to fluid collection in the abdominal cavity with a vague presentation of clinical symptoms. Particularly, SHiP causes a life-threatening condition with the coexistence of intrauterine pregnancy, since this dangerous complication significantly increases the maternal and fetal mortality. Herein, we present two cases of nontraumatic SHiP in the second and third trimester of pregnancy, respectively. CASE PRESENTATION: The pregnant woman in case 1 was admitted to our hospital owing to severe paroxysmal shoulder pain along with abdominal pain. Her medical history was remarkably recorded with endometriosis and adenomyosis. At the emergency room, an ultrasound scan revealed a live fetus corresponding to 21 weeks and 3 days and free fluid in the abdominal cavity. She was subsequently diagnosed with SHiP and underwent immediate laparotomy for hemostatic procedures. During the postpartum course, the patient was uneventfully monitored. Unfortunately, the patient delivered on the 4th postoperative day in spite of the initial administration of tocolytic agents and close monitoring. The primigravid woman in case 2 complained of lower abdominal pain and vaginal bleeding. The patient's history was noted with ovarian tumor removal. At admission, the sonography scan revealed free fluid in the abdominal cavity, a fetus at 34 weeks and 3 days gestational age with bradycardia of 70 bpm, and a laboratory test showed a low hemoglobin level. Thus, exploratory laparotomy and hysterotomy were performed at the same time due to fetal distress. The postpartum course was uneventful. The patient was discharged 5 days later. CONCLUSIONS: In pregnant women with a history of endometriosis, adenomyosis, or ovarian tumor removal, acute abdominal pain combined with the presence of free fluid collection in the intraperitoneal cavity, and a decreased hemoglobin levels should be first assessed as SHiP originating from the spontaneous rupture of abnormal vascular proliferation. Proper management is strongly indicated for an emergent laparotomy to control the active bleeding point, thus increasing the survival rate for both mother and neonate.

10.
World J Pediatr Congenit Heart Surg ; 14(3): 309-315, 2023 05.
Article in English | MEDLINE | ID: mdl-36895130

ABSTRACT

Background: This study evaluates mortality and intermediate outcomes of the arterial switch operation (ASO) for transposition or Taussig-Bing anomaly with single sinus coronary artery (CA) anatomy in a high-volume cardiac program in Vietnam. Methods: We retrospectively reviewed and performed risk factor analysis pertaining to 41 consecutive patients who presented with single sinus CA anatomy and who underwent ASO from January 2010 to December 2016 in our center. Results: The median age at operation was 43 days [interquartile range (IQR): 20-65] and the median weight was 3.6 kg (IQR: 3.4-4.0). Four in-hospital deaths (9.8%), of which one was related to coronary insufficiency. There were no late deaths, with a median follow-up time of 7.2 years. Survival for all patients with single sinus CA was 90.2% at 1 year and remained constant at 5 years and 10 years after ASO. The presence of a coexisting aortic arch anomaly was the only risk factor for overall mortality identified in this study (hazard ratio: 8.66, P = .031, 95% confidence interval: 1.21-61.92). There were three cardiac reoperations. Freedom from reintervention after ASO for patients with single sinus CA at 1 year, 5 years, and 10 years were 97.3%, 91.9%, and 91.9%, respectively. Interestingly, among all patients undergoing ASO during this time period (n = 304), single-sinus CA anatomy was not a risk factor for overall death (P = .758). Conclusions: In a high-volume cardiac program in a lower middle-income country like Vietnam, ASO can be safely performed with single sinus CA anatomy, irrespective of the presenting coronary anatomy.


Subject(s)
Arterial Switch Operation , Heart Defects, Congenital , Transposition of Great Vessels , Humans , Infant , Arterial Switch Operation/adverse effects , Transposition of Great Vessels/surgery , Retrospective Studies , Coronary Vessels , Developing Countries , Treatment Outcome , Heart Defects, Congenital/surgery , Risk Factors , Reoperation , Follow-Up Studies
11.
Taiwan J Obstet Gynecol ; 62(1): 22-30, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36720545

ABSTRACT

OBJECTIVE: Placenta accreta spectrum disorders (PASD) are the leading cause which results in highly maternal mortality during pregnancy. Although hysterectomy has been the gold standard for PASD, the recent study along with our experience has been demonstrated that the association between uterine myometrial resection and transverse B-Lynch suture in conservative management might be effective in the appropriate patients, thus we hereby attempted to determine this issue. MATERIALS AND METHODS: A retrospective observational study enrolled 65 patients at Tu Du Hospital in Vietnam between January 2017 and December 2018. This study included all pregnant women above 28 weeks of gestational age, who had undergone cesarean delivery due to PASD diagnosed preoperatively by ultrasound or upon laparotomy. Additionally, all patients who desired uterine preservation underwent modified one-step conservative uterine surgery (MOSCUS), avoiding peripartum hysterectomy. RESULTS: Overall, the rate of successful preservation was 93.8%. Other main outcomes such as average operative blood loss was 987 mL, mean blood transfusion was 831 ± 672 mL; mean operative time was 135 ± 31 min and average postoperative time was 5.79 days. Postoperative complications included six out of 65 cases due to intraoperative bleeding and postoperative infection, requiring hysterectomy in 4 patients. CONCLUSION: MOSCUS was associated with less operative blood loss and blood transfusion amount. Its success rate of uterine preservation was approximately 94% in our study. Thus, this method can be acceptable in PASD management at our maternity health care center. Further studies might be necessary to evaluate the long-term effects of this method in PASD management.


Subject(s)
Placenta Accreta , Postpartum Hemorrhage , Female , Pregnancy , Humans , Blood Loss, Surgical , Placenta Accreta/surgery , Placenta Accreta/diagnosis , Vietnam , Postpartum Hemorrhage/etiology , Retrospective Studies , Hysterectomy/methods , Postoperative Complications/surgery , Hospitals
12.
J Family Reprod Health ; 16(3): 220-228, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36569258

ABSTRACT

Objective: Umbilical cord hematoma and uterine torsion are extremely rare complications in pregnancy. However, these should not be neglected in clinical practice in condition of abnormal fetal heart monitoring without others suspects. We hereby report rare case of umbilical cord hematoma and uterine torsion as well as review the literature. Through this report, we aim to mention on an available tool to investigate spontaneous umbilical cord hematoma on fetal well-being in such a case. Case report : A women aged 35 years old (G1P0) admitted to our hospital for term gestation with uncomplicated pregnancy, except large uterine fibroid accompanied with cervical pessary. Then, an uncommon complication of umbilical cord hematoma was revealed accidentally upon cesarean section. Particularly, this dramatic event was happened along with an asymptomatic uterine torsion noticed at the same time. Preoperative diagnosis of two rare complications was missed, hence, we extracted timely baby based on another modality of management, computerized cardiotocography. Conclusion: Umbilical cord hematoma along with uterine torsion is difficult to diagnosis due to its rarity. Moreover, no available tool could investigate umbilical cord hematoma prior to delivery. Surveillance on fetal heart rate monitoring may be helpful in this situation.

13.
Int J Surg Case Rep ; 99: 107603, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36150330

ABSTRACT

INTRODUCTION AND IMPORTANCE: Placenta accreta spectrum disorders (PASD) refer to an uncommon obstetrical conditions leading to significant life-threatening obstetrical issue for mothers and foetus during pregnancy. Rarely, this pathology can occur in the uterus without a history of uterine surgery, localize at unusual site of the uterus, and result in the spontaneous uterine rupture. We herein reported two unusual cases managed successfully in the third trimester of pregnancy at our tertiary referral hospital. CASE PRESENTATION: Two pregnant women were hospitalized at our maternity hospital for a dilemma diagnosis of PASD without history of previous caesarean scar. Following the suspected images of PASD on ultrasound combined with a hematoma anterior to the body of the uterus, especially a sudden onset of abdominal pain and intraperitoneal fluid without a clear etiology, we made the suspected diagnosis of uterine rupture associated with PASD. Moreover, a gradual reduction of hemoglobin concentration also supported this diagnosis. Both cases underwent immediately caesarean hysterectomy for saving the life of the mother and baby following suspicion. CLINICAL DISCUSSION: PASD associated with an unscarred uterus is an uncommon placentation during pregnancy. Although an extremely rare cases, PASD may be present without association with placenta praevia. Timely management by caesarean hysterectomy can avoid adverse maternal-foetal outcomes. CONCLUSION: PASD can be appeared on the uterus without a previous uterine scar, thus leading to unexpected complications during pregnancy. Closely strict monitoring helps avoiding the materno-foetal mortality. Further data is needed to summarize this rarely uncommon entity.

14.
Medicine (Baltimore) ; 101(51): e32137, 2022 Dec 23.
Article in English | MEDLINE | ID: mdl-36595786

ABSTRACT

BACKGROUND: To understand the prevalent issues and challenges in the provision of care for dyslipidemia and hypertension in Vietnamese adults, quantification of patient journey stages (awareness, screening, diagnosis, treatment, adherence, and control) was performed in this semi-systematic review. METHODS: The EMBASE and MEDLINE databases were searched for English articles published between 2010 and 2019. Thesis abstracts, letters to the editor, editorials, case studies, and studies on patient subgroups or nationally unrepresentative studies, were excluded. Articles from Google, the Incidence and Prevalence Database, the World Health Organization, Vietnam's Ministry of Health, and those suggested by the authors were also included. The last search was run on December 10, 2019 for dyslipidemia and hypertension. RESULTS: A reviewer independently screened 586 retrievals for dyslipidemia and 177 retrievals for hypertension, and extracted data from 2 articles on dyslipidemia and 6 articles on hypertension that were included in the final synthesis. CONCLUSION: The data generated in this review will help overcome these issues and barriers to patient care in populations with these 2 conditions.


Subject(s)
Cardiovascular Diseases , Dyslipidemias , Hypertension , Adult , Humans , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/prevention & control , Vietnam/epidemiology , Hypertension/epidemiology , Hypertension/therapy , Dyslipidemias/epidemiology , Dyslipidemias/therapy
15.
JMIR Res Protoc ; 10(10): e30947, 2021 Oct 07.
Article in English | MEDLINE | ID: mdl-34617915

ABSTRACT

BACKGROUND: Tobacco kills more than 8 million people each year, mostly in low- and middle-income countries. In Vietnam, 1 in every 2 male adults smokes tobacco. Vietnam has set up telephone Quitline counseling that is available to all smokers, but it is underused. We previously developed an automated and effective motivational text messaging system to support smoking cessation among US smokers. OBJECTIVE: The aim of this study is to adapt the aforementioned system for rural Vietnamese smokers to promote cessation of tobacco use, both directly and by increasing the use of telephone Quitline counseling services and nicotine replacement therapy. Moreover, we seek to enhance research and health service capacity in Vietnam. METHODS: We are testing the effectiveness of our culturally adapted motivational text messaging system by using a community-based randomized controlled trial design (N=600). Participants were randomly allocated to the intervention (regular motivational and assessment text messages) or control condition (assessment text messages only) for a period of 6 months. Trial recruitment took place in four communes in the Hung Yen province in the Red River Delta region of Vietnam. Recruitment events were advertised to the local community, facilitated by community health workers, and occurred in the commune health center. We are assessing the impact of the texting system on 6-month self-reported and biochemically verified smoking cessation, as well as smoking self-efficacy, uptake of the Quitline, and use of nicotine replacement therapy. In addition to conducting the trial, the research team also provided ongoing training and consultation with the Quitline during the study period. RESULTS: Site preparation, staff training, intervention adaptation, participant recruitment, and baseline data collection were completed. The study was funded in August 2017; it was reviewed and approved by the University of Massachusetts Medical School Institutional Review Board in 2017. Recruitment began in November 2018. A total of 750 participants were recruited from four communes, and 700 (93.3%) participants completed follow-up by March 2021. An analysis of the trial results is in progress; results are expected to be published in late 2022. CONCLUSIONS: This study examines the effectiveness of mobile health interventions for smoking in rural areas in low- and middle-income countries, which can be implemented nationwide if proven effective. In addition, it also facilitates significant collaboration and capacity building among a variety of international partners, including researchers, policy makers, Quitline counselors, and community health workers. TRIAL REGISTRATION: ClinicalTrials.gov NCT03567993; https://clinicaltrials.gov/ct2/show/NCT03567993. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/30947.

17.
Int J Numer Method Biomed Eng ; 35(11): e3253, 2019 11.
Article in English | MEDLINE | ID: mdl-31441222

ABSTRACT

The aim of this work is to develop a novel computational approach to facilitate the modeling of angiogenesis during tumor growth. The preexisting vasculature is modeled as a 1D inclusion and embedded into the 3D tissue through a suitable coupling method, which allows for nonmatching meshes in 1D and 3D domain. The neovasculature, which is formed during angiogenesis, is represented in a homogenized way as a phase in our multiphase porous medium system. This splitting of models is motivated by the highly complex morphology, physiology, and flow patterns in the neovasculature, which are challenging and computationally expensive to resolve with a discrete, 1D angiogenesis and blood flow model. Moreover, it is questionable if a discrete representation generates any useful additional insight. By contrast, our model may be classified as a hybrid vascular multiphase tumor growth model in the sense that a discrete, 1D representation of the preexisting vasculature is coupled with a continuum model describing angiogenesis. It is based on an originally avascular model which has been derived via the thermodynamically constrained averaging theory. The new model enables us to study mass transport from the preexisting vasculature into the neovasculature and tumor tissue. We show by means of several illustrative examples that it is indeed capable of reproducing important aspects of vascular tumor growth phenomenologically.


Subject(s)
Models, Biological , Vascular Neoplasms/pathology , Blood Vessels/physiology , Humans , Neovascularization, Pathologic , Porosity , Regional Blood Flow , Vascular Neoplasms/blood supply
18.
Int J Numer Method Biomed Eng ; 34(11): e3139, 2018 11.
Article in English | MEDLINE | ID: mdl-30070046

ABSTRACT

In this paper, we propose a finite element-based immersed method to treat the mechanical coupling between a deformable porous medium model (PM) and an immersed solid model (ISM). The PM is formulated as a homogenized, volume-coupled two-field model, comprising a nearly incompressible solid phase that interacts with an incompressible Darcy-Brinkman flow. The fluid phase is formulated with respect to the Lagrangian finite element mesh, following the solid phase deformation. The ISM is discretized with an independent Lagrangian mesh and may behave arbitrarily complex (it may, eg, be compressible, grow, and perform active deformations). We model two distinct types of interactions, namely, (1) the immersed fluid-structure interaction (FSI) between the ISM and the fluid phase in the PM and (2) the immersed structure-structure interaction (SSI) between the ISM and the solid phase in the PM. Within each time step, we solve both FSI and SSI, employing strongly coupled partitioned schemes. This novel finite element method establishes a main building block of an evolving computational framework for modeling and simulating complex biomechanical problems, with focus on key phenomena during cell migration. Cell movement is strongly influenced by mechanical interactions between the cell body and the surrounding tissue, ie, the extracellular matrix (ECM). In this context, the PM represents the ECM, ie, a fibrous scaffold of structural proteins interacting with interstitial flow, and the ISM represents the cell body. The FSI models the influence of fluid drag, and the SSI models the force transmission between cell and ECM at adhesions sites.


Subject(s)
Finite Element Analysis , Cell Adhesion/physiology , Cell Communication/physiology , Cell Movement/physiology , Computer Simulation , Humans , Porosity
19.
Comput Methods Appl Mech Eng ; 340: 657-683, 2018 Oct 01.
Article in English | MEDLINE | ID: mdl-33132456

ABSTRACT

We present a dynamic vascular tumor model combining a multiphase porous medium framework for avascular tumor growth in a consistent Arbitrary Lagrangian Eulerian formulation and a novel approach to incorporate angiogenesis. The multiphase model is based on Thermodynamically Constrained Averaging Theory and comprises the extracellular matrix as a porous solid phase and three fluid phases: (living and necrotic) tumor cells, host cells and the interstitial fluid. Angiogenesis is modeled by treating the neovasculature as a proper additional phase with volume fraction or blood vessel density. This allows us to define consistent inter-phase exchange terms between the neovasculature and the interstitial fluid. As a consequence, transcapillary leakage and lymphatic drainage can be modeled. By including these important processes we are able to reproduce the increased interstitial pressure in tumors which is a crucial factor in drug delivery and, thus, therapeutic outcome. Different coupling schemes to solve the resulting five-phase problem are realized and compared with respect to robustness and computational efficiency. We find that a fully monolithic approach is superior to both the standard partitioned and a hybrid monolithic-partitioned scheme for a wide range of parameters. The flexible implementation of the novel model makes further extensions (e.g., inclusion of additional phases and species) straightforward.

20.
Article in Vietnamese | WPRIM (Western Pacific) | ID: wpr-5731

ABSTRACT

Study STEPWise approach to non-communicable disease (NCD) risk factors surveillance. This approach allows us to supervise general risk factors of NCDs, so that appropriate interventions for each group of risks and subjects can be given. This approach includes 3 steps. Step 1: to assess risk behaviours for NCDs such as smoking, drinking alcohol, less consumption of vegetable, sedentary lifestyle. Step 2: to measure some body indexes such as blood pressure, weight, height, waist circumference, etc. Step 3: perform some blood tests such as glycemia, lipidemia, etc.


Subject(s)
Risk Factors , Disease
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