Publications by authors named "Michael Ma"

109 Publications

Endo-hepatology: An emerging field.

World J Gastrointest Endosc 2021 Aug;13(8):296-301

Division of Gastroenterology, Lenox Hill Hospital, Northwell Health, New York, NY 10075, United States.

Gastroenterologists have long been spearheading the care of patients with various forms of liver disease. The diagnosis and management of liver disease has traditionally been a combination of clinical, laboratory, and imaging findings coupled with percutaneous and intravascular procedures with endoscopy largely limited to screening for and therapy of esophageal and gastric varices. As the applications of diagnostic and therapeutic endoscopic ultrasound (EUS) have evolved, it has found a particular niche within hepatology now coined endo-hepatology. Here we discuss several EUS-guided procedures such as liver biopsy, shear wave elastography, direct portal pressure measurement, paracentesis, as well as EUS-guided therapies for variceal hemorrhage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4253/wjge.v13.i8.296DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8394184PMC
August 2021

Commentary: Simplifying complex heart defects through modeling.

Authors:
Michael Ma

JTCVS Tech 2021 Jun 20;7:203. Epub 2021 Feb 20.

Division of Pediatric Cardiac Surgery, Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, Calif.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.xjtc.2021.02.018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8311673PMC
June 2021

Cannabis Exposure Decreases Need for Blood Pressure Support During General Anesthesia in Orthopedic Trauma Surgery.

Cannabis Cannabinoid Res 2021 Jul 5. Epub 2021 Jul 5.

Department of Anesthesiology and Perioperative Care and University of California-Irvine, Orange, California, USA.

As cannabis use continues to increase in popularity, it is important to investigate how it impacts public health in all sectors of the population, including patients undergoing anesthetic management. This retrospective study focuses on the orthopedic trauma population presenting through an emergency department (ED) and receiving a urine drug screen (UDS) with subsequent urgent surgical intervention. We aimed to evaluate differences in response to general anesthesia in patients with exposure to THC, a major cannabinoid, compared to controls that screened negative for THC. All ED visits at UC Irvine, a level 1 trauma center between November 4, 2017 and January 7, 2020, were evaluated in this study. Only adult patients who received a UDS and underwent urgent orthopedic trauma surgery within 48 h of ED visit were included in this study. Additional inclusion criteria required an anesthesia time greater than 1 h as well as anesthesia induction and intubation while in the operating room. Overall, we analyzed a total of 221 adult patients. When adjusting for demographic variability, there were statistically significant differences in response to general anesthesia between these two groups. The THC-positive (THC(+)) group was less likely to receive intraoperative vasopressors, had higher mean arterial blood pressure and mean diastolic blood pressure, needed less total fluid input and had a lower overall fluid balance. Chronic exposure to THC has been shown to downregulate cannabinoid 1 receptors and cause alterations in endocannabinoid tone. These are two potential mechanisms by which the THC(+) group in our study may have become more resistant to the typically observed hypotensive effects of general anesthesia. The present study suggests that prior use of cannabis, objectively assessed by urinalysis, results in a decreased need for blood pressure support during general anesthesia. The physiological basis for this phenomenon is unclear, but possible causes might include the downregulation of vascular cannabinoid receptor 1 and/or altered endocannabinoid levels after exposure to cannabis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/can.2021.0009DOI Listing
July 2021

Combined endoscopic ultrasound-guided gastrojejunostomy and anterograde biliary stenting.

Endoscopy 2021 Jun 18. Epub 2021 Jun 18.

Division of Gastroenterology, Lenox Hill Hospital, New York, New York, United States.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/a-1499-6234DOI Listing
June 2021

Commentary: The Devil in Z Details.

Authors:
Michael Ma

Semin Thorac Cardiovasc Surg 2021 Jun 9. Epub 2021 Jun 9.

Division of Pediatric Cardiac Surgery, Department of Cardiothoracic Surgery, Stanford University, Stanford, California. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1053/j.semtcvs.2021.06.003DOI Listing
June 2021

Preexisting right ventricular systolic dysfunction in high-risk patients undergoing non.emergent open abdominal surgery: A retrospective cohort study.

Ann Card Anaesth 2021 Jan-Mar;24(1):62-71

Department of Anesthesiology and Perioperative Care, University of California Irvine, 333 City Blvd. West Suite 2150.

Background: The prognostic value of right ventricular systolic dysfunction in high-risk patients undergoing non-emergent open abdominal surgery is unknown. Here, we aim to evaluate whether presence of preexisting right ventricular systolic dysfunction in this surgical cohort is independently associated with higher incidence of postoperative major adverse cardiac events and all-cause in-hospital mortality.

Methods: This is a single-centered retrospective study. Patients identified as American Society Anesthesiology Classification III and IV who had a preoperative echocardiogram within 1 year of undergoing non-emergent open abdominal surgery between January 2010 and May 2017 were included in the study. Incidence of postoperative major cardiac adverse events and all-cause in-hospital mortality were collected. Multivariable logistic regression was performed in a step-wise manner to identify independent association between preexisting right ventricular systolic dysfunction with outcomes of interest.

Results: Preexisting right ventricular systolic dysfunction was not associated with postoperative major adverse cardiac events (P = 0.26). However, there was a strong association between preexisting right ventricular systolic dysfunction and all-cause in-hospital mortality (P = 0.00094). After multivariate analysis, preexisting right ventricular systolic dysfunction continued to be an independent risk factor for all-cause in-hospital mortality with an odds ratio of 18.9 (95' CI: 1.8-201.7; P = 0.015).

Conclusion: In this retrospective study of high-risk patients undergoing non-emergent open abdominal surgery, preexisting right ventricular systolic dysfunction was found to have a strong association with all-cause in-hospital mortality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/aca.ACA_46_19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8081126PMC
May 2021

Compassionate Deactivation of Pediatric Ventricular Assist Devices: A Review of 14 Cases.

J Pain Symptom Manage 2021 Sep 25;62(3):523-528. Epub 2021 Apr 25.

Department of Anesthesia, Stanford University School of Medicine (D.C.), Palo Alto, California, USA.

Context: Compassionate deactivation (CD) of ventricular assist device (VAD) support is a recognized option for children when the burden of therapy outweighs the benefits.

Objectives: To describe the prevalence, indications, and outcomes of CD of children supported by VADs at the end of life.

Methods: Review of cases of CD at our institution between 2011 and 2020. To distinguish CD from other situations where VAD support is discontinued, patients were excluded from the study if they died during resuscitation (including extracorporeal membrane oxygenation), experienced brain or circulatory death prior to deactivation, or experienced a non-survivable brain injury likely to result in imminent death regardless of VAD status.

Results: Of 24 deaths on VAD, 14 (58%) were CD. Median age was 5.7 (interquartile range (IQR) 0.6, 11.6) years; 6 (43%) had congenital heart disease; 4 (29%) were on a device that can be used outside of the hospital. CD occurred after 40 (IQR: 26, 75) days of support; none while active transplant candidates. CD discussions were initiated by the caregiver in 6 (43%) cases, with the remainder initiated by a medical provider. Reasons for CD were multifactorial, including end-organ injury, infection, and stroke. CD occurred with endotracheal extubation and/or discontinuation of inotropes in 12 (86%) cases, and death occurred within 10 (IQR: 4, 23) minutes of CD.

Conclusion: CD is the mode of death in more than half of our VAD non-survivors and is pursued for reasons primarily related to noncardiac events. Caregivers and providers both initiate CD discussions. Ventilatory and inotropic support is often withdrawn at time of CD with ensuing death.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jpainsymman.2021.01.125DOI Listing
September 2021

Recurrent fibrovascular granulation on PhotoFix® bovine pericardium causing systemic and pulmonary venous obstruction after repair of scimitar syndrome.

Cardiol Young 2021 May 8;31(5):829-830. Epub 2021 Mar 8.

Division of Pediatric Cardiology, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, CA, USA.

A young adult with late diagnosis of scimitar syndrome underwent infradiaphragmatic baffling of the scimitar vein to left atrium through an intra-atrial tunnel using PhotoFix® bovine pericardium with recurrent extensive fibrovascular granulation of the patch causing pulmonary and systemic venous obstruction leading to eventual explantation of the bovine pericardium.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1017/S1047951121000822DOI Listing
May 2021

Alternative to heart-lung transplantation for end-stage tetralogy of Fallot with major aortopulmonary collaterals: Simultaneous heart transplantation and pulmonary artery reconstruction.

J Heart Lung Transplant 2021 05 17;40(5):392-394. Epub 2021 Feb 17.

Department of Cardiothoracic Surgery, Division of Pediatric Cardiac Surgery, Stanford University School of Medicine, Palo Alto, California.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.healun.2021.02.003DOI Listing
May 2021

Acute respiratory failure in immunosuppressed patients admitted to ICU.

J Crit Care 2021 Jun 3;63:26-31. Epub 2021 Feb 3.

Department of Intensive Care Medicine, Multidisciplinary Intensive Care Research Organization (MICRO), St. James's Hospital, Dublin, Ireland; Trinity College Dublin, School of Medicine, Dublin, Ireland; Hospital Clinic, IDIBAPS, Universidad de Barcelona, Ciberes, Barcelona, Spain. Electronic address:

Introduction: The number of hospitalized immunosuppressed adults is a growing and often develop severe complications that require admission to an Intensive Care Unit (ICU). The main cause of admission is acute respiratory failure (ARF). The goal of the study was to determine if ARF represents an independent risk factor for hospital mortality and in particular, we sought to ascertain if any risk factors were independently and identifiably associated with a bad outcome.

Methods: We perform a retrospective study of a prospectively collected data from patients admitted to an ICU. Adult patients with known immunosuppressive condition admitted to ICU were included.

Results: A total of 248 patients were included. Of 248 patients, 117 (47.2%) had a diagnosis of ARF at the time of ICU admission. Patients with ARF had a significantly higher in-hospital mortality (53.4% vs. 28.2% p = 0.001). Factors independently associated with hospital mortality were diagnosis of ARF at ICU admission, the presence of septic shock, use of continuous renal replacement therapy and failure of high-flow nasal canula(HFNC)/non-invasive (NIV) respiratory therapies.

Conclusion: We identified ARF on admission and failure of HFNC/NIV to be independently associated with increased hospital mortality in immunosuppressed patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcrc.2021.01.004DOI Listing
June 2021

Longevity of Large Aortic Allograft Conduits in Tetralogy With Major Aortopulmonary Collaterals.

Ann Thorac Surg 2021 Feb 16. Epub 2021 Feb 16.

Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California; Department of Pediatrics, Stanford University School of Medicine, Stanford, California.

Background: Appropriate conduit selection for right ventricle (RV)-to-pulmonary artery (PA) connection has been extensively studied, with older implantation age, pulmonary (vs aortic) homografts, and true sizing associated with increased longevity. Notably, patients with PA arborization abnormalities (ie, major aortopulmonary collateral arteries [MAPCAs]) are reported to require earlier and more frequent conduit interventions. We aim to understand the behavior of large-diameter aortic homografts in patients with MAPCAs, which are programmatically utilized at our institution.

Methods: This is a single-center retrospective cohort study including all children less than 12 years of age who underwent RV-PA connection using an aortic homograft greater than or equal to 16 mm diameter between 2002 and 2019, with a primary outcome of freedom from any RV-PA reintervention and a secondary outcome of freedom from surgical reintervention. Patients were grouped by absolute and indexed conduit sizes for further analysis.

Results: A total of 336 conduits were followed for a median of 3.0 years; transcatheter (n = 30) or surgical (n = 35) reintervention was performed on 64 conduits. Estimated freedom from reintervention and surgical replacement was 84% and 90% at 5 years. Younger age and smaller absolute conduit size were associated with earlier reintervention, but conduit Z-score (median 3.5) was not associated with outcome.

Conclusions: The programmatic use of oversized aortic homograft RV-PA conduits in the surgical repair of MAPCAs provides a focused experience that demonstrates similar longevity to reported best alternatives. Secondarily, conduit oversizing may improve durability and enables an increased likelihood of nonoperative reintervention.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.athoracsur.2021.01.054DOI Listing
February 2021

Detection of arterial pressure waveform error using machine learning trained algorithms.

J Clin Monit Comput 2021 Feb 1. Epub 2021 Feb 1.

Department of Anesthesiology, CUB Erasme, Université Libre de Bruxelles, Brussels, Belgium.

In critically ill and high-risk surgical room patients, an invasive arterial catheter is often inserted to continuously measure arterial pressure (AP). The arterial waveform pressure measurement, however, may be compromised by damping or inappropriate reference placement of the pressure transducer. Clinicians, decision support systems, or closed-loop applications that rely on such information would benefit from the ability to detect error from the waveform alone. In the present study we hypothesized that machine-learning trained algorithms could discriminate three types of transducer error from accurate monitoring with receiver operator characteristic (ROC) curve areas greater than 0.9. After obtaining written consent, patient arterial line waveform data was collected in the operating room in real-time during routine surgery requiring arterial pressure monitoring. Three deliberate error conditions were introduced during monitoring: Damping, Transducer High, and Transducer Low. The waveforms were split up into 10 s clips that were featurized. The data was also either calibrated against the patient's own baseline or left uncalibrated. The data was then split into training and validation sets, and machine-learning algorithms were run in a Monte-Carlo fashion on the training data with variable sized training sets and hyperparameters. The algorithms with the highest balanced accuracy were pruned, then the highest performing algorithm in the training set for each error state (High, Low, Damped) for both calibrated and uncalibrated data was finally tested against the validation set and the ROC and precision-recall curve area-under the curve (AUC) calculated. 38 patients were enrolled in the study with a mean age of 52 ± 15 years. A total of 40 h of monitoring time was recorded with approximately 120,000 heart beats featurized. For all error states, ROC AUCs for algorithm performance on classification of the state were greater than 0.9; when using patient-specific calibrated data AUCs were 0.94, 0.95, and 0.99 for the transducer low, transducer high, and damped conditions respectively. Machine-learning trained algorithms were able to discriminate arterial line transducer error states from the waveform alone with a high degree of accuracy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10877-020-00642-4DOI Listing
February 2021

Mid-Term Outcomes After Unifocalization Guided by Intraoperative Pulmonary Flow Study.

World J Pediatr Congenit Heart Surg 2021 Jan;12(1):76-83

Department of Cardiothoracic Surgery, 24349Lucile Packard Children's Hospital Heart Center, Stanford University School of Medicine, Palo Alto, CA, USA.

Background: Repair of tetralogy of Fallot (TOF) with major aortopulmonary collateral arteries (MAPCAs) requires unifocalization of pulmonary circulation, intracardiac repair with the closure of the ventricular septal defect, and placement of a right ventricle (RV) to pulmonary artery (PA) conduit. The decision to perform complete repair is sometimes aided by an intraoperative flow study to estimate the total resistance of the reconstructed pulmonary circulation.

Methods: We reviewed patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs to evaluate acute and mid-term outcomes after repair with and without flow studies and to characterize the relationship between PA pressure during the flow study and postrepair RV pressure.

Results: Among 579 patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs, 99 (17%) had an intraoperative flow study during one (n = 91) or more (n = 8) operations to determine the suitability for a complete repair. There was a reasonably good correlation between mean PA pressure at 3 L/min/m during the flow study and postrepair RV pressure and RV:aortic pressure ratio. Acute and mid-term outcomes (median: 3.8 years) after complete repair in the flow study patients (n = 78) did not differ significantly from those in whom the flow study was not performed (n = 444). Furthermore, prior failed flow study was not associated with differences in outcome after subsequent intracardiac repair.

Conclusions: The intraoperative flow study remains a useful adjunct for determining the suitability for complete repair in a subset of patients undergoing surgery for TOF/MAPCAs, as it is reasonably accurate for estimating postoperative PA pressure and serves as a reliable guide for the feasibility of single-stage complete repair.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/2150135120964427DOI Listing
January 2021

HNO to NO Conversion Mechanism with Copper Zinc Superoxide Dismutase, Comparison with Heme Protein Mediated Conversions, and the Origin of Questionable Reversibility.

Chemistry 2021 Mar 16;27(15):5019-5027. Epub 2021 Feb 16.

Department of Chemistry and Chemical Biology, Stevens Institute, of Technology, 1 Castle Point on Hudson, Hoboken, NJ, 07030, USA.

The interconversion of NO and HNO, via copper zinc superoxide dismutase (CuZnSOD), is important in biomedicine and for HNO detection. Many mechanistic questions, including the decades-long debate on reversibility, were resolved in this work. Calculations of various active-site and full-protein models show that the basic mechanism is proton-coupled electron transfer with a computed barrier of 10.98 kcal mol , which is in excellent agreement with experimental results (10.62 kcal mol ), and this nonheme protein-mediated reaction has many significant mechanistic differences compared with the conversions mediated by heme proteins due to geometric and electronic factors. The reasons for the irreversible nature of this conversion and models with the first thermodynamically favorable and kinetically feasible mechanism for the experimental reverse reaction were discovered. Such results are the first for nonheme enzyme mediated HNO to NO conversions, which shall facilitate other related studies and HNO probe development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/chem.202100015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7954974PMC
March 2021

Intravenous Infusion of the β-Adrenergic Receptor Antagonist APD418 Improves Left Ventricular Systolic Function in Dogs With Systolic Heart Failure.

J Card Fail 2021 Feb 25;27(2):242-252. Epub 2020 Dec 25.

Arena Pharmaceuticals, Inc., San Diego, California.

Background: Unlike β- and β-adrenergic receptors (ARs), β-AR stimulation inhibits cardiac contractility and relaxation. In the failing left ventricular (LV) myocardium, β-ARs are upregulated, and can be maladaptive in the setting of decompensation by contributing to LV dysfunction. This study examined the effects of intravenous infusions of the β-AR antagonist APD418 on cardiovascular function and safety in dogs with systolic heart failure (HF).

Methods And Results: Three separate studies were performed in 21 dogs with coronary microembolization-induced HF (LV ejection fraction [LVEF] of approximately 35%). Studies 1 and 2 (n = 7 dogs each) were APD418 dose escalation studies (dosing range, 0.35-15.00 mg/kg/h) designed to identify an effective dose of APD418 to be used in study 3. Study 3, the sustained efficacy study, (n = 7 dogs) was a 6-hour constant intravenous infusion of APD418 at a dose of 4.224 mg/kg (0.70 mg/kg/h) measuring key hemodynamic endpoints (e.g., EF, cardiac output, the time velocity integral of the mitral inflow velocity waveform representing early filling to time-velocity integral representing left atrial contraction [Ei/Ai]). Studies 1 and 2 showed a dose-dependent increase of LVEF and Ei/Ai, the latter being an index of LV diastolic function. In study 3, infusion of APD418 over 6 hours increased LVEF from 31 ± 1% to 38 ± 1% (P < .05) and increased Ei/Ai from 3.4 ± 0.4 to 4.9 ± 0.5 (P < .05). Vehicle had no effect on the LVEF or Ei/Ai. In study 3, APD418 had no significant effects on the HR or the systemic blood pressure.

Conclusions: Intravenous infusions of APD418 in dogs with systolic HF elicit significant positive inotropic and lusitropic effects. These findings support the development of APD418 for the in-hospital treatment of patients with an acute exacerbation of chronic HF.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cardfail.2020.12.008DOI Listing
February 2021

Angiographic Anatomy of Major Aortopulmonary Collateral Arteries and Association With Early Surgical Outcomes in Tetralogy of Fallot.

J Am Heart Assoc 2020 12 5;9(24):e017981. Epub 2020 Dec 5.

Division of Pediatric Cardiology Department of Pediatrics Stanford University School of Medicine Palo Alto CA.

Background Due in part to the heterogeneity of the pulmonary circulation in patients with tetralogy of Fallot and major aortopulmonary collateral arteries (MAPCAs), research on this condition has focused on relatively basic anatomic characteristics. We aimed to detail pulmonary artery (PA) and MAPCA anatomy in a large group of infants, assess relationships between anatomy and early surgical outcomes, and consider systems for classifying MAPCAs. Methods and Results All infants ( <1 year of age) undergoing first cardiac surgery for tetralogy of Fallot/MAPCAs from 2001 to 2019 at Stanford University were identified. Preoperative angiograms delineating supply to all 18 pulmonary segments were reviewed for details of each MAPCA and the arborization and size of central PAs. We studied 276 patients with 1068 MAPCAs and the following PA patterns: 152 (55%) incompletely arborizing PAs, 48 (17%) normally arborizing PAs, 45 (16%) absent PAs, and 31 (11%) unilateral MAPCAs. There was extensive anatomic variability, but no difference in early outcomes according to PA arborization or the predominance of PAs or MAPCAs. Patients with low total MAPCA and/or PA cross-sectional area were less likely to undergo complete repair. Conclusions MAPCA anatomy is highly variable and essentially unique for each patient. Though each pulmonary segment can be supplied by a MAPCA, central PA, or both, all anatomic combinations are similarly conducive to a good repair. Total cross-sectional area of central PA and MAPCA material is an important driver of outcome. We elucidate a number of novel associations between anatomic features, but the extreme variability of the pulmonary circulation makes a granular tetralogy of Fallot/MAPCA classification system unrealistic.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/JAHA.120.017981DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7955371PMC
December 2020

Unilateral Branch Pulmonary Artery Origin From a Solitary Arterial Trunk With Major Aortopulmonary Collaterals to the Contralateral Lung: Anatomic and Developmental Considerations.

Semin Thorac Cardiovasc Surg 2021 Autumn;33(3):780-786. Epub 2020 Nov 9.

Department of Pediatrics, Division of Pediatric Cardiology, Stanford University School of Medicine, Palo Alto, California.

In both truncus arteriosus communis (TAC) and tetralogy of Fallot (TOF), there is a rare phenotype that includes a single branch pulmonary artery (PA) arising from a solitary great artery and major aortopulmonary collaterals (MAPCAs) supplying the contralateral lung. We describe the intracardiac and great vessel anatomy of infants with this phenotype, consider rationale for classifying patients as TOF vs TAC, and describe surgical outcomes. Our institution's surgical database was reviewed for patients with a single branch PA from a solitary arterial trunk and contralateral MAPCAs from 2007 to 2019. Demographic, imaging, and surgical data were collected and described. All 11 patients underwent complete repair with a median right ventricular to aortic pressure ratio of 0.36 (range 0.26-0.50). At 0.1-9.1 years after repair (median 0.8 years) there was approximately balanced left-right lung perfusion (median 52% to the right lung, range 34-74%). The MAPCA lungs exemplified the full spectrum of PA and MAPCA anatomy, from absent intrapericardial PAs with all single supply MAPCAs to a normally arborizing PA with all dual supply MAPCAs and present pulmonary valve leaflet tissue. All patients had a systemic semilunar valve with 3 thin and similarly sized leaflets and fibrous continuity with the tricuspid valve, and all had coronary origins and outflow tract morphology more consistent with TOF. It is appropriate to classify all patients with a single anomalous PA from a solitary arterial trunk and MAPCAs to the contralateral lung as TOF rather than TAC Type A3. All variants were amenable to surgical repair.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1053/j.semtcvs.2020.11.009DOI Listing
November 2020

Comprehensive Ex Vivo Comparison of 5 Clinically Used Conduit Configurations for Valve-Sparing Aortic Root Replacement Using a 3-Dimensional-Printed Heart Simulator.

Circulation 2020 10 5;142(14):1361-1373. Epub 2020 Oct 5.

Department of Cardiothoracic Surgery (M.J.P., A.M.I.-M., M.B., H.W., C.E.H., H.J.L., J.M.F., A.D.T., Y.Z., M.M., J.W.M., Y.J.W.), Stanford University, CA.

Background: Many graft configurations are clinically used for valve-sparing aortic root replacement, some specifically focused on recapitulating neosinus geometry. However, the specific impact of such neosinuses on valvular and root biomechanics and the potential influence on long-term durability are unknown.

Methods: Using a custom 3-dimenstional-printed heart simulator with porcine aortic roots (n=5), the anticommissural plication, Stanford modification, straight graft (SG), Uni-Graft, and Valsalva graft configurations were tested in series using an incomplete counterbalanced measures design, with the native root as a control, to mitigate ordering effects. Hemodynamic and videometric data were analyzed using linear models with conduit as the fixed effect of interest and valve as a fixed nuisance effect with post hoc pairwise testing using Tukey's correction.

Results: Hemodynamics were clinically similar between grafts and control aortic roots. Regurgitant fraction varied between grafts, with SG and Uni-Graft groups having the lowest regurgitant fractions and anticommissural plication having the highest. Root distensibility was significantly lower in SG versus both control roots and all other grafts aside from the Stanford modification (≤0.01 for each). All grafts except SG had significantly higher cusp opening velocities versus native roots (<0.01 for each). Relative cusp opening forces were similar between SG, Uni-Graft, and control groups, whereas anticommissural plication, Stanford modification, and Valsalva grafts had significantly higher opening forces versus controls (<0.01). Cusp closing velocities were similar between native roots and the SG group, and were significantly lower than observed in the other conduits (≤0.01 for each). Only SG and Uni-Graft groups experienced relative cusp closing forces approaching that of the native root, whereas relative forces were >5-fold higher in the anticommissural plication, Stanford modification, and Valsalva graft groups.

Conclusions: In this ex vivo modeling system, clinically used valve-sparing aortic root replacement conduit configurations have comparable hemodynamics but differ in biomechanical performance, with the straight graft most closely recapitulating native aortic root biomechanics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/CIRCULATIONAHA.120.046612DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7531510PMC
October 2020

Outcomes in Patients with Alagille Syndrome and Complex Pulmonary Artery Disease.

J Pediatr 2021 02 24;229:86-94.e4. Epub 2020 Sep 24.

Department of Pediatrics, Lucille Packard Children's Hospital Stanford and Stanford University, Palo Alto, CA; Department of Cardiothoracic Surgery, Lucille Packard Children's Hospital Stanford and Stanford University, Palo Alto, CA.

Objective: To assess outcomes in a large cohort of patients with Alagille syndrome (ALGS) who underwent pulmonary artery reconstruction surgery for complex pulmonary artery disease.

Study Design: Patients with ALGS who underwent pulmonary artery reconstruction surgery at Lucile Packard Children's Hospital Stanford were reviewed. Patients were examined as an overall cohort and based on the primary cardiovascular diagnosis: severe isolated branch pulmonary artery stenosis, tetralogy of Fallot (TOF) without major aortopulmonary collateral arteries (MAPCAs), or TOF with MAPCAs.

Results: Fifty-one patients with ALGS underwent pulmonary artery surgery at our center, including 22 with severe branch pulmonary artery stenosis, 9 with TOF without MAPCAs, and 20 with TOF and MAPCAs. Forty-one patients (80%) achieved a complete repair. Five of the patients with TOF with MAPCAs (25%) underwent complete repair at the first surgery, compared with 8 (89%) with TOF without MAPCAs and 19 (86%) with isolated branch pulmonary artery stenosis. At a median follow-up of 1.7 years after the first surgery, 39 patients (76%) were alive, 36 with a complete repair and a median pulmonary artery:aortic systolic pressure of 0.38. Nine patients (18%), including 8 with isolated branch pulmonary artery stenosis, underwent liver transplantation.

Conclusions: Most patients with ALGS and complex pulmonary artery disease can undergo complete repair with low postoperative right ventricular pressure. Patients with TOF/MAPCAs had the worst outcomes, with higher mortality and more frequent pulmonary artery interventions compared with patients with TOF without MAPCAs or isolated branch pulmonary artery stenosis. Complex pulmonary artery disease is not a contraindication to liver transplantation in patients with ALGS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jpeds.2020.09.053DOI Listing
February 2021

Recent outcomes of the extracardiac Fontan procedure in patients with hypoplastic left heart syndrome.

Ann Pediatr Cardiol 2020 Jul-Sep;13(3):186-193. Epub 2020 Jun 29.

Department of Pediatrics, Division of Pediatric Cardiology, Stanford University School of Medicine, Stanford, CA, USA.

Objective: To investigate patient-related factors, echocardiographic, and anatomic variables associated with immediate and long-term clinical outcomes after extracardiac Fontan procedure at our institution.

Materials And Methods: Retrospective review of preoperative cardiac catheterizations and echocardiograms as well as medical records of all children with hypoplastic left heart syndrome (HLHS) who underwent Fontan between June 2002 and December 2018.

Results: Seventy-seven patients with HLHS were included (age 4 years [1.5-11.7]). Seventy patients (91%) received a nonfenestrated Fontan and 57 patients (74%) underwent Fontan without cardiopulmonary bypass (CPB). Presence of a Fontan fenestration ( = 0.69) and use of CPB ( = 0.79) did not differ between those with <2 weeks compared to those with ≥2 weeks of chest tube drainage. There were no differences in either pre- or intra-operative hemodynamics between patients who weighed <15 kg compared to those who weighed ≥15 kg at time of surgery; incidence of death, transplant, and transplant listing were similar between weight groups. Inferior vena cava (IVC) diameter z-score did not differ among patients with and without chylous chest tube drainage ( = 0.78), with and without development of protein losing enteropathy ( = 0.23), or death/heart transplant/transplant listing compared to survivors without transplant ( = 0.26).

Conclusion: In HLHS patients undergoing Fontan, preoperative weight and IVC diameter appeared to have no influence on immediate postoperative outcomes. Performing the Fontan off CPB and with a fenestration also conferred no added clinical benefit. These observations should be considered when deciding optimal timing for Fontan completion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/apc.APC_5_20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7437630PMC
June 2020

A fast and green reversed-phase HPLC method with fluorescence detection for simultaneous determination of amlodipine and celecoxib in their newly approved fixed-dose combination tablets.

J Sep Sci 2020 Aug 22;43(16):3197-3205. Epub 2020 Jun 22.

Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Tanta University, Tanta, Egypt.

A fast, green, sensitive, and accurate analytical method using high-performance liquid chromatography couple with fluorescence detection was established and validated for the simultaneous determination of amlodipine besylate and celecoxib in their recently approved fixed-dose combination tablets (1:20). Separation of the two drugs was achieved on C reversed-phase column (Thermo ODS Hypersil, 4.6 × 250 mm, particle size 5 µm) using acetonitrile:potassium phosphate buffer (50 mM; pH 5.5, 60:40 v/v) as a mobile phase at 40°C, which eluted at a rate of 1 mL/min. Detection was carried out with excitation and emission wavelengths of 360 and 446 nm for amlodipine and 265 and 359 nm for celecoxib, respectively. The method was linear over a concentration range of 0.05-2 and 0.05-10 µg/mL and limit of detection reached to 0.017 and 0.0167 µg/mL for amlodipine and celecoxib, respectively. The developed method was successfully applied to assess the cited drugs in their newly FDA approved fixed-dose combination tablet dosage form. Furthermore, the method was found to be sensitive and eco-friendly green alternative to the reported methods as it was evaluated according to the green analytical procedure index tool guidelines and analytical Eco-Scale.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jssc.202000345DOI Listing
August 2020

Unifocalization and pulmonary artery reconstruction in patients with tetralogy of Fallot and major aortopulmonary collateral arteries who underwent surgery before referral.

J Thorac Cardiovasc Surg 2020 Nov 11;160(5):1268-1280.e1. Epub 2020 Apr 11.

Department of Cardiothoracic Surgery, Lucile Packard Children's Hospital Heart Center Clinical and Translational Research Program, Stanford University School of Medicine, Stanford, Calif.

Objective: The study objective was to characterize and analyze outcomes in patients with tetralogy of Fallot and major aortopulmonary collateral arteries who had undergone surgery elsewhere before referral (prereferral surgery).

Methods: Patients with tetralogy of Fallot and major aortopulmonary collateral arteries who underwent surgery between 2001 and 2019 at our center were reviewed. Prereferral surgery and unoperated patients were compared, as were subsets of prereferral surgery patients who had undergone different types of prior procedures. Primary outcomes included complete repair with survival to 6 months, death, and perioperative metrics.

Results: Of 576 patients studied, 200 (35%) had undergone a wide range and number of prior operations elsewhere, including 92 who had pulmonary blood supply through a shunt and 108 who had a right ventricle pulmonary artery connection. Patients who underwent prereferral surgery with an existing right ventricle pulmonary artery connection had undergone more prereferral surgery procedures than those with a shunt and were more likely to have a right ventricle outflow tract pseudoaneurysm or pulmonary artery stent (all P < .001) at the time of referral. The cumulative incidences of complete repair and death were similar regardless of prereferral surgery status, but the cumulative incidence of complete repair with 6-month survival was higher (P = .002) and of death lower (P = .18) in patients who had prior right ventricle pulmonary artery connection compared with those who had received a prior shunt only.

Conclusions: Our comprehensive management strategy for tetralogy of Fallot and major aortopulmonary collateral arteries can be applied with excellent procedural results in both unoperated patients and those who have undergone multiple and varied procedures elsewhere.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jtcvs.2020.03.062DOI Listing
November 2020

In Vivo Validation of Restored Chordal Biomechanics After Mitral Ring Annuloplasty in a Rare Ovine Case of Natural Chronic Functional Mitral Regurgitation.

J Cardiovasc Dev Dis 2020 05 15;7(2). Epub 2020 May 15.

Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA.

Mitral valve chordae tendineae forces are elevated in the setting of mitral regurgitation (MR). Ring annuloplasty is an essential component of surgical repair for MR, but whether chordal forces are reduced after mitral annuloplasty has never been validated in vivo. Here, we present an extremely rare ovine case of natural, severe chronic functional MR, in which we used force-sensing fiber Bragg grating neochordae to directly measure chordal forces in the baseline setting of severe MR, as well as after successful mitral ring annuloplasty repair. Overall, our report is the first to confirm in vivo that mitral ring annuloplasty reduces elevated chordae tendineae forces associated with chronic functional MR.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/jcdd7020017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7344614PMC
May 2020

A novel cross-species model of Barlow's disease to biomechanically analyze repair techniques in an ex vivo left heart simulator.

J Thorac Cardiovasc Surg 2021 05 19;161(5):1776-1783. Epub 2020 Feb 19.

Department of Cardiothoracic Surgery, Stanford University, Stanford, Calif; Department of Bioengineering, Stanford University, Stanford, Calif. Electronic address:

Objective: Barlow's disease remains challenging to repair, given the complex valvular morphology and lack of quantitative data to compare techniques. Although there have been recent strides in ex vivo evaluation of cardiac mechanics, to our knowledge, there is no disease model that accurately simulates the morphology and pathophysiology of Barlow's disease. The purpose of this study was to design such a model.

Methods: To simulate Barlow's disease, a cross-species ex vivo model was developed. Bovine mitral valves (n = 4) were sewn into a porcine annulus mount to create excess leaflet tissue and elongated chordae. A heart simulator generated physiologic conditions while hemodynamic data, high-speed videography, and chordal force measurements were collected. The regurgitant valves were repaired using nonresectional repair techniques such as neochord placement.

Results: The model successfully imitated the complexities of Barlow's disease, including redundant, billowing bileaflet tissues with notable regurgitation. After repair, hemodynamic data confirmed reduction of mitral leakage volume (25.9 ± 2.9 vs 2.1 ± 1.8 mL, P < .001) and strain gauge analysis revealed lower primary chordae forces (0.51 ± 0.17 vs 0.10 ± 0.05 N, P < .001). In addition, the maximum rate of change of force was significantly lower postrepair for both primary (30.80 ± 11.38 vs 8.59 ± 4.83 N/s, P < .001) and secondary chordae (33.52 ± 10.59 vs 19.07 ± 7.00 N/s, P = .006).

Conclusions: This study provides insight into the biomechanics of Barlow's disease, including sharply fluctuating force profiles experienced by elongated chordae prerepair, as well as restoration of primary chordae forces postrepair. Our disease model facilitates further in-depth analyses to optimize the repair of Barlow's disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jtcvs.2020.01.086DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7815072PMC
May 2021

Postoperative Recovery of Left Ventricular Function following Repair of Large Ventricular Septal Defects in Infants.

J Am Soc Echocardiogr 2020 03 19;33(3):368-377. Epub 2019 Dec 19.

Division of Pediatric Cardiology, Department of Pediatrics, Stanford University School of Medicine, Palo Alto, California.

Introduction: Early postoperative left ventricular (LV) dysfunction is observed following repair of large ventricular septal defects (VSDs), but the frequency and rate of recovery of LV function are unknown. This study aims to characterize the incidence and rate of recovery of postoperative LV dysfunction following repair of large VSDs and to improve understanding of LV mechanics before and after VSD repair.

Methods: Infants who underwent surgical repair of an isolated large VSD were included. Pre- and postoperative echocardiographic images were reviewed, and LV function was assessed by both conventional echocardiography and speckle-tracking strain analyses. Postoperative LV dysfunction was defined as an LV ejection fraction (LVEF) < 50% using the 5/6 area-length method. Echocardiograms were reviewed to assess LVEF and LV volume through 1-year follow-up.

Results: Of 104 infants evaluated (median age, 0.31 [0.22, 0.56] years), all had normal preoperative LVEF and 39 (38%) had postoperative LV dysfunction. Follow-up echocardiograms were available in 31 (80%) patients, all of whom had LVEF > 50% within 9 months of surgery. Lower preoperative apical four-chamber longitudinal strain (A4LS) and greater LV end-diastolic volume indexed to body surface area were independently associated with postoperative LV dysfunction. An absolute preoperative A4LS < 16.7% (area under the curve = 0.87; 95% CI, 0.78-0.95; P < .001) was most strongly associated with postoperative dysfunction.

Conclusions: Infants with LV dysfunction following repair of large VSDs recover function within 9 months. Preoperative A4LS can be helpful to detect subclinical LV dysfunction in the setting of a large hemodynamically significant VSD and guide postoperative expectations for providers and families.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.echo.2019.10.003DOI Listing
March 2020

Feasibility Evaluation of Commercially Available Video Conferencing Devices to Technically Direct Untrained Nonmedical Personnel to Perform a Rapid Trauma Ultrasound Examination.

Diagnostics (Basel) 2019 Nov 14;9(4). Epub 2019 Nov 14.

Department of Anesthesiology, UCI Medical Center, Orange, CA 92868, USA.

Point-of-care ultrasound (POCUS) is a rapidly expanding discipline that has proven to be a valuable modality in the hospital setting. Recent evidence has demonstrated the utility of commercially available video conferencing technologies, namely, FaceTime (Apple Inc, Cupertino, CA, USA) and Google Glass (Google Inc, Mountain View, CA, USA), to allow an expert POCUS examiner to remotely guide a novice medical professional. However, few studies have evaluated the ability to use these teleultrasound technologies to guide a nonmedical novice to perform an acute care POCUS examination for cardiac, pulmonary, and abdominal assessments. Additionally, few studies have shown the ability of a POCUS-trained cardiac anesthesiologist to perform the role of an expert instructor. This study sought to evaluate the ability of a POCUS-trained anesthesiologist to remotely guide a nonmedically trained participant to perform an acute care POCUS examination. A total of 21 nonmedically trained undergraduate students who had no prior ultrasound experience were recruited to perform a three-part ultrasound examination on a standardized patient with the guidance of a remote expert who was a POCUS-trained cardiac anesthesiologist. The examination included the following acute care POCUS topics: (1) cardiac function via parasternal long/short axis views, (2) pneumothorax assessment via pleural sliding exam via anterior lung views, and (3) abdominal free fluid exam via right upper quadrant abdominal view. Each examiner was given a handout with static images of probe placement and actual ultrasound images for the three views. After a brief 8 min tutorial on the teleultrasound technologies, a connection was established with the expert, and they were guided through the acute care POCUS exam. Each view was deemed to be complete when the expert sonographer was satisfied with the obtained image or if the expert sonographer determined that the image could not be obtained after 5 min. Image quality was scored on a previously validated 0 to 4 grading scale. The entire session was recorded, and the image quality was scored during the exam by the remote expert instructor as well as by a separate POCUS-trained, blinded expert anesthesiologist. A total of 21 subjects completed the study. The average total time for the exam was 8.5 min (standard deviation = 4.6). A comparison between the live expert examiner and the blinded postexam reviewer showed a 100% agreement between image interpretations. A review of the exams rated as three or higher demonstrated that 87% of abdominal, 90% of cardiac, and 95% of pulmonary exams achieved this level of image quality. A satisfaction survey of the novice users demonstrated higher ease of following commands for the cardiac and pulmonary exams compared to the abdominal exam. The results from this pilot study demonstrate that nonmedically trained individuals can be guided to complete a relevant ultrasound examination within a short period. Further evaluation of using telemedicine technologies to promote POCUS should be evaluated.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/diagnostics9040188DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6963664PMC
November 2019

A Prospective Observational Cohort Study of Calls for Help in a Tertiary Care Academic Operating Room Suite.

Anesth Analg 2019 09;129(3):e83-e85

From the Department of Anesthesiology & Perioperative Care, University of California at Irvine, Irvine, California.

While significant literature exists on hospital-based "code calls," there is a lack of research on calls for help in the operating room (OR). The purpose of this study was to quantify the rate and nature of calls for help in the OR of a tertiary care hospital. For a 1-year period, all calls were recorded in the main OR at The University of California, Irvine Medical Center. The average rate of calls per 1000 anesthesia hours was 1.4 (95% CI, 1.1-1.8), corresponding to a rate of 5.0 (3.8-6.5) calls per 1000 cases. Airway (44%), cardiac (32%), and hemorrhagic (11%) emergencies were the most common etiologies. Thirty-day mortality approached 11% for patients who required a call for help in the OR.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1213/ANE.0000000000003667DOI Listing
September 2019

Surgical Repair of Ebstein's Anomaly Using a Bicuspidization Approach.

Ann Thorac Surg 2019 12 5;108(6):1875-1882. Epub 2019 Aug 5.

Division of Pediatric Cardiac Surgery, Lucile Packard Children's Hospital Stanford, Stanford University School of Medicine, Stanford, California.

Background: Ebstein's anomaly of the tricuspid valve is a rare and heterogeneous form of congenital heart defect. The purpose of this study was to review the surgical experience with Ebstein's anomaly at a single institution.

Methods: This was a retrospective review of 47 patients with Ebstein's anomaly who were previously unrepaired and underwent surgical repair of the tricuspid valve. Our surgical approach repairs the leaflets at the preexisting level and does not attempt to reposition the hinge points at the anatomic annulus. The median age at surgery was 17 years (range, 2-53). Preoperatively the median degree of tricuspid regurgitation was graded as moderate-to-severe, and the median right ventricular function was slightly below normal.

Results: Forty-seven patients underwent surgical repair without any mortality. Forty-three patients (91%) had a successful repair as evidenced by a decrease in the amount of tricuspid regurgitation to trace/mild. Four patients (9%) had an unsuccessful initial repair. Thirteen patients (29%) underwent a concomitant bidirectional Glenn procedure. Eight patients (17%) required late reoperation. Seven of these 8 patients initially had undergone a successful repair but returned with recurrent tricuspid regurgitation. Six of the 8 late reoperations entailed a re-repair, whereas 2 (4%) required tricuspid valve replacement.

Conclusions: The bicuspidization surgical technique resulted in 91% percent of patients undergoing a successful initial repair. These results suggest this technique may be a viable alternative to the "cone" procedure.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.athoracsur.2019.06.026DOI Listing
December 2019

Use of a supramolecular polymeric hydrogel as an effective post-operative pericardial adhesion barrier.

Nat Biomed Eng 2019 08 7;3(8):611-620. Epub 2019 Aug 7.

Department of Bioengineering, Stanford University, Stanford, CA, USA.

Post-operative adhesions form as a result of normal wound healing processes following any type of surgery. In cardiac surgery, pericardial adhesions are particularly problematic during reoperations, as surgeons must release the adhesions from the surface of the heart before the intended procedure can begin, thereby substantially lengthening operation times and introducing risks of haemorrhage and injury to the heart and lungs during sternal re-entry and cardiac dissection. Here we show that a dynamically crosslinked supramolecular polymer-nanoparticle hydrogel, with viscoelastic and flow properties that enable spraying onto tissue as well as robust tissue adherence and local retention in vivo for two weeks, reduces the formation of pericardial adhesions. In a rat model of severe pericardial adhesions, the hydrogel markedly reduced the severity of the adhesions, whereas commercial adhesion barriers (including Seprafilm and Interceed) did not. The hydrogels also reduced the severity of cardiac adhesions (relative to untreated animals) in a clinically relevant cardiopulmonary-bypass model in sheep. This viscoelastic supramolecular polymeric hydrogel represents a promising clinical solution for the prevention of post-operative pericardial adhesions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41551-019-0442-zDOI Listing
August 2019
-->