Tolerability of Olaparib Combined with Abiraterone in Patients with Metastatic Castration-resistant Prostate Cancer: Further Results from the Phase 3 PROpel Trial

BACKGROUND

The PROpel study (NCT03732820) demonstrated a statistically significant progression-free survival benefit with olaparib plus abiraterone versus placebo plus abiraterone in the first-line metastatic castration-resistant prostate cancer (mCRPC) setting, irrespective of homologous recombination repair mutation status.

OBJECTIVE

We report additional safety analyses from PROpel to increase clinical understanding of the adverse-event (AE) profiles of olaparib plus abiraterone versus placebo plus abiraterone.

DESIGN, SETTING, AND PARTICIPANTS

A randomised (1:1), double-blind, placebo-controlled trial was conducted at 126 centres in 17 countries (October 2018-January 2020). Patients had mCRPC and no prior systemic mCRPC treatment.

INTERVENTION

Olaparib (300 mg bid) or placebo with abiraterone (1000 mg od) plus prednisone/prednisolone (5 mg bid).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The data cut-off date was July 30, 2021. Safety was assessed by AE reporting (Common Terminology Criteria for Adverse Events v4.03) and analysed descriptively.

RESULTS AND LIMITATIONS

The most common AEs (all grades) for olaparib plus abiraterone versus placebo plus abiraterone were anaemia (46.0% vs 16.4%), nausea (28.1% vs 12.6%), and fatigue (27.9% vs 18.9%). Grade ≥3 anaemia occurred in 15.1% versus 3.3% of patients in the olaparib plus abiraterone versus placebo plus abiraterone arm. The incidences of the most common AEs for olaparib plus abiraterone peaked early, within 2 mo, and were managed typically by dose modifications or standard medical practice. Overall, 13.8% versus 7.8% of patients discontinued treatment with olaparib plus abiraterone versus placebo plus abiraterone because of an AE; 3.8% versus 0.8% of patients discontinued because of anaemia. More venous thromboembolism events were observed in the olaparib plus abiraterone arm (any grade, 7.3%; grade ≥3, 6.8%) than in the placebo plus abiraterone arm (any grade, 3.3%; grade ≥3, 2.0%), most commonly pulmonary embolism (6.5% vs 1.8% for olaparib plus abiraterone vs placebo plus abiraterone).

CONCLUSIONS

Olaparib plus abiraterone has a manageable and predictable safety profile.

PATIENT SUMMARY

The PROpel trial showed that in patients who had not received any previous treatment for metastatic castration-resistant prostate cancer, olaparib combined with abiraterone was more effective in delaying progression of the disease than abiraterone alone. Most side effects caused by combining olaparib with abiraterone could be managed with supportive care methods, by pausing olaparib administration for a short period of time and/or by reducing the dose of olaparib.

Long-Term Efficacy and Safety of Enzalutamide Monotherapy in Elderly Patients with Metastatic Castration-Resistant Prostate Cancer: A Case Report

Introduction

Prostate cancer is one of the most common cancers in men. Despite the sharp rise in incidence, mortality is decreasing. ARTA preparations are preferred options for asymptomatic or mildly symptomatic patients with mCRPC. The use of enzalutamide in elderly patients with mCRPC is risky and depends on a number of factors. An increased risk of falls and fractures has been shown.

Case Presentation

We present a case report of an elderly patient with mCRPC treated with enzalutamide with very good long-term tolerance and efficacy.

Conclusion

Despite the older age, no reduction of therapy was necessary in the patient due to good tolerance. Administration of enzalutamide in full doses resulted in a very good effect of therapy.

Autophagy modulators influence the content of important signalling molecules in PS-positive extracellular vesicles

Extracellular vesicles (EVs) are important mediators of intercellular communication in the tumour microenvironment. Many studies suggest that cancer cells release higher amounts of EVs exposing phosphatidylserine (PS) at the surface. There are lots of interconnections between EVs biogenesis and autophagy machinery. Modulation of autophagy can probably affect not only the quantity of EVs but also their content, which can deeply influence the resulting pro-tumourigenic or anticancer effect of autophagy modulators. In this study, we found that autophagy modulators autophinib, CPD18, EACC, bafilomycin A1 (BAFA1), 3-hydroxychloroquine (HCQ), rapamycin, NVP-BEZ235, Torin1, and starvation significantly alter the composition of the protein content of phosphatidylserine-positive EVs (PS-EVs) produced by cancer cells. The greatest impact had HCQ, BAFA1, CPD18, and starvation. The most abundant proteins in PS-EVs were proteins typical for extracellular exosomes, cytosol, cytoplasm, and cell surface involved in cell adhesion and angiogenesis. PS-EVs protein content involved mitochondrial proteins and signalling molecules such as SQSTM1 and TGFβ1 pro-protein. Interestingly, PS-EVs contained no commonly determined cytokines, such as IL-6, IL-8, GRO-α, MCP-1, RANTES, and GM-CSF, which indicates that secretion of these cytokines is not predominantly mediated through PS-EVs. Nevertheless, the altered protein content of PS-EVs can still participate in the modulation of the fibroblast metabolism and phenotype as p21 was accumulated in fibroblasts influenced by EVs derived from CPD18-treated FaDu cells. The altered protein content of PS-EVs (data are available via ProteomeXchange with identifier PXD037164) also provides information about the cellular compartments and processes that are affected by the applied autophagy modulators. Video Abstract.

Magnetically Driven Self-Degrading Zinc-Containing Cystine Microrobots for Treatment of Prostate Cancer

Prostate cancer is the most commonly diagnosed tumor disease in men, and its treatment is still a big challenge in standard oncology therapy. Magnetically actuated microrobots represent the most promising technology in modern nanomedicine, offering the advantage of wireless guidance, effective cell penetration, and non-invasive actuation. Here, new biodegradable magnetically actuated zinc/cystine-based microrobots for in situ treatment of prostate cancer cells are reported. The microrobots are fabricated via metal-ion-mediated self-assembly of the amino acid cystine encapsulating superparamagnetic Fe₃ O₄ nanoparticles (NPs) during the synthesis, which allows their precise manipulation by a rotating magnetic field. Inside the cells, the typical enzymatic reducing environment favors the disassembly of the aminoacidic chemical structure due to the cleavage of cystine disulfide bonds and disruption of non-covalent interactions with the metal ions, as demonstrated by in vitro experiments with reduced nicotinamide adenine dinucleotide (NADH). In this way, the cystine microrobots served for site-specific delivery of Zn²⁺ ions responsible for tumor cell killing via a "Trojan horse effect". This work presents a new concept of cell internalization exploiting robotic systems' self-degradation, proposing a step forward in non-invasive cancer therapy.

Abiraterone and Olaparib for Metastatic Castration-Resistant Prostate Cancer

Abiraterone and Olaparib for Metastatic Prostate CancerPatients with metastatic castration-resistant prostate cancer, regardless of homologous recombination repair gene mutation status, received either abiraterone and olaparib or abiraterone and placebo in the first-line setting. Imaging-based progression-free survival was 24.8 months for patients treated with abiraterone and olaparib versus 16.6 months for those receiving abiraterone alone.

Tolerability of abiraterone (abi) combined with olaparib (ola) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC): Further results from the phase III PROpel trial

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Background: The Phase III PROpel (NCT03732820) trial demonstrated at interim analysis a statistically significant clinical benefit from combining ola + abi in the first-line (1L) mCRPC setting vs placebo (pbo) + abi. Benefit was seen irrespective of a pt’s homologous recombination repair mutation (HRRm) status; median radiographic progression-free survival (rPFS) 24.8 for ola + abi vs 16.6 months for pbo + abi (hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.54–0.81; P<0.0001). The safety profile of ola + abi was shown to be consistent with that for the individual drugs. We report additional interim safety analysis from PROpel. Methods: Eligible pts were ≥18 years with mCRPC, had received no prior chemotherapy or next-generation hormonal agent treatment at mCRPC stage, and were unselected by HRRm status. Pts were randomized 1:1 to abi (1000 mg qd) plus prednisone/prednisolone with either ola (300 mg bid) or pbo. Primary endpoint was investigator-assessed rPFS. Safety was assessed in all pts receiving ≥1 dose of study treatment by adverse event (AE) reporting (CTCAE v4.03). Results: 398 pts received ola + abi and 396 pbo + abi (safety analysis set). At data cut-off (July 30, 2021), median total duration of exposure for ola was 17.5 vs 15.7 months for pbo, and for abi 18.2 months in the ola + abi arm and 15.7 in the pbo + abi arm. Anemia (n=183) was the most common AE in the ola + abi arm, and 34% of these 183 events were managed by dose interruption, 23% by dose reduction, and 8% resulted in treatment discontinuation. Anemia and pulmonary embolism (PE) were the only Grade ≥3 AEs in ≥5% of pts (anemia: ola + abi, 15.1% vs pbo + abi, 3.3%; PE: 6.5% vs 1.8%, respectively). Most PEs were detected incidentally on radiographic imaging (69.2% and 71.4% in the ola + abi and pbo + abi arms, respectively) and no pts discontinued. More pts in the ola + abi arm experienced venous thromboembolism (Table). Arterial thromboembolism and cardiac failure AEs were balanced between the treatment arms. No AE of myelodysplastic syndrome/acute myeloid leukemia was reported in either treatment arm. COVID-19 was reported more frequently with ola + abi (8.3% vs 4.5%). Conclusions: PROpel demonstrated a predictable safety profile for ola + abi given in combination to pts with 1L mCRPC unselected by HRRm status. AEs of cardiac failure and arterial thromboembolism were reported at similar frequency in both treatment arms. The majority of PEs were asymptomatic. The safety profile of abiraterone was not adversely impacted by its combination with olaparib. Clinical trial information: NCT03732820. [Table: see text]

Cancer Cells Viscoelasticity Measurement by Quantitative Phase and Flow Stress Induction

Cell viscoelastic properties are affected by the cell cycle, differentiation, pathological processes such as malignant transformation. Therefore, evaluation of the mechanical properties of the cells proved to be an approach to obtaining information on the functional state of the cells. Most of the currently used methods for cell mechanophenotypisation are limited by low robustness or the need for highly expert operation. In this paper, the system and method for viscoelasticity measurement using shear stress induction by fluid flow is described and tested. Quantitative Phase Imaging (QPI) is used for image acquisition because this technique enables to quantify optical path length delays introduced by the sample, thus providing a label-free objective measure of morphology and dynamics. Viscosity and elasticity determination were refined using a new approach based on the linear system model and parametric deconvolution. The proposed method allows high-throughput measurements during live cell experiments and even through a time-lapse, where we demonstrated the possibility of simultaneous extraction of shear modulus, viscosity, cell morphology, and QPI-derived cell parameters like circularity or cell mass. Additionally, the proposed method provides a simple approach to measure cell refractive index with the same setup, which is required for reliable cell height measurement with QPI, an essential parameter for viscoelasticity calculation. Reliability of the proposed viscoelasticity measurement system was tested in several experiments including cell types of different Young/shear modulus and treatment with cytochalasin D or docetaxel, and an agreement with atomic force microscopy was observed. The applicability of the proposed approach was also confirmed by a time-lapse experiment with cytochalasin D washout, where an increase of stiffness corresponded to actin repolymerisation in time.

Metabolic tricks of cancer cells

One of the characteristics of cancer cells important for tumorigenesis is their metabolic plasticity. Indeed, in various stress conditions, cancer cells can reshape their metabolic pathways to support the increased energy request due to continuous growth and rapid proliferation. Moreover, selective pressures in the tumor microenvironment, such as hypoxia, acidosis, and competition for resources, force cancer cells to adapt by complete reorganization of their metabolism. In this review, we highlight the characteristics of cancer metabolism and discuss its clinical significance, since overcoming metabolic plasticity of cancer cells is a key objective of modern cancer therapeutics and a better understanding of metabolic reprogramming may lead to the identification of possible targets for cancer therapy.

Parametric Deconvolution for Cancer Cells Viscoelasticity Measurements from Quantitative Phase Images

In this contribution, we focused on optimising a dynamic flow-based shear stress system to achieve a reliable platform for cell shear modulus (stiffness) and viscosity assessment using quantitative phase imaging. The estimation of cell viscoelastic properties is influenced by distortion of the shear stress waveform, which is caused by the properties of the flow system components (i.e., syringe, flow chamber and tubing). We observed that these components have a significant influence on the measured cell viscoelastic characteristics. To suppress this effect, we applied a correction method utilizing parametric deconvolution of the flow system's optimized impulse response. Achieved results were compared with the direct fitting of the Kelvin-Voigt viscoelastic model and the basic steady-state model. The results showed that our novel parametric deconvolution approach is more robust and provides a more reliable estimation of viscosity with respect to changes in the syringe's compliance compared to Kelvin-Voigt model.

The dual role of asporin in breast cancer progression

Asporin has been reported as a tumor suppressor in breast cancer, while asporin-activated invasion has been described in gastric cancer. According to our in silico search, high asporin expresion associates with significantly better relapse free survival (RFS) in patients with low-grade tumors but RFS is significantly worse in patients with grade 3 tumors. In line with other studies, we have confirmed asporin expression by RNA scope in situ hybridization in cancer associated fibroblasts. We have also found asporin expression in the Hs578T breast cancer cell line which we confirmed by quantitative RT-PCR and western blotting. From multiple testing, we found that asporin can be downregulated by bone morphogenetic protein 4 while upregulation may be facilited by serum-free cultivation or by three dimensional growth in stiff Alvetex scaffold. Downregulation by shRNA inhibited invasion of Hs578T as well as of CAFs and T47D cells. Invasion of asporin-negative MDA-MB-231 and BT549 breast cancer cells through collagen type I was enhanced by recombinant asporin. Besides other investigations, large scale analysis of aspartic acid repeat polymorphism will be needed for clarification of the asporin dual role in progression of breast cancer.

Secondary Combined Immunodeficiency in Pediatric Patients after the Fontan Operation: Three Case Reports

The Fontan operation or total cavopulmonal connection (TCPC) is a palliative surgical correction of rare and complex inborn cardiac malformations that are characterized by univentricular circulation. Protein-losing enteropathy (PLE) develops in 4-13% of patients after the Fontan procedure. Fontan-related PLE leads to secondary combined immunodeficiency marked by hypogammaglobulinemia and predominantly CD4+ lymphocytopenia. Here, we present 3 case reports of patients with secondary immunodeficiency after the Fontan operation. The severity of hypogammaglobulinemia correlated with the nature of the infectious complications; however, clinical manifestations of T cell deficiency such as severe viral or opportunistic infections were not observed. The clinical consequences of the secondary combined immunodeficiency were modified by immunoglobulin replacement treatment and antibiotic prophylaxis. Heart transplantation led to the resolution of PLE signs and the restitution of IgG levels in 1 transplanted patient. Our experience shows that the immunological follow-up was delayed in all 3 patients. We suggest that all patients should be followed regularly by a clinical immunologist after the Fontan surgery.

Absence of maternal cell contamination in mesenchymal stromal cell cultures derived from equine umbilical cord tissue

This study aimed to determine whether maternal cell contamination exists in cells derived from equine umbilical cord tissue, a perspective material for cell-based therapies in veterinary medicine. Potential maternal cell contamination was analyzed at DNA level via a set of 16 microsatellite markers in cells originating from the cord tissue of 22 foals. In these cells no maternal cell contamination was detected at a sensitivity level of 0.01%. Our results suggest that equine umbilical cord tissue-derived cells are entirely of fetal origin.

MiR-34b is associated with clinical outcome in triple-negative breast cancer patients

Background

Breast cancer is the most common malignancy with the highest incidence rates among women worldwide. Triple-negative breast cancer (TNBC) represents the major phenotype of basal-like molecular subtype of breast cancer, characterized by higher incidence in young women and a very poor prognosis. MicroRNAs (miRNAs) are small non-coding RNAs playing significant role in the pathogenesis of many cancers including breast cancer. Therefore, miRNAs are also potential prognostic and/or predictive biomarkers in triple-negative breast cancer patients.

Methods

Thirty-nine TNBC patients with available formalin-fixed paraffin-embedded (FFPE) tissues were enrolled in the study. MiR-34a, miR-34b, and miR-34c were analyzed using qRT-PCR and correlated to clinico-pathological features of TNBC patients.

Results

Expression levels of miR-34b significantly correlate with disease free survival (DFS) (p = 0.0020, log-rank test) and overall survival (OS) (p = 0.0008, log-rank test) of TNBC patients. No other significant associations between miR-34a, miR-34b, and miR-34c with available clinical pathological data were observed.

Conclusions

MiR-34b expression negatively correlates with disease free survival and overall survival in TNBC patients. Thus, miR-34b may present a new promising prognostic biomarker in TNBC patients, but independent validations are necessary.

Cytokine expression by human peripheral blood dendritic cells stimulated in vitro with HIV-1 and herpes simplex virus

Dendritic cells are potent stimulators of Ag-specific T cell responses and have been implicated in the pathogenesis of HIV-1 and other viral infections. Although cytokines may be involved in both of these processes, there is little information on the expression of cytokines by human blood dendritic cells. We characterized cytokine gene and protein expression in dendritic cells that were purified from normal human PBMC by flow cytometry and stimulated in vitro for up to 24 h with HIV-1 or herpes simplex virus (HSV). The unstimulated, uncultured dendritic cells were defined by their phenotype (HLA DR+ CD3- CD19- CD16- CD56- CD14-) and distinct morphology, lack of mRNA expression for CD3, CD14 and CD19, and presence of mRNA for CD4 and CD83. The purified dendritic cells also expressed CD4 (70-90%), CD33 (36-48%), and CD11c (44-54%); lacked CD1a expression (<1%); and were potent stimulators of an allogeneic MLR. The stimulated dendritic cells expressed mRNA for IFN-alpha, IL-1alpha, IL-1beta, IL-6, IL-10, IL-12, GM-CSF, and TNF-alpha within 4 to 12 h as determined by reverse transcription-PCR, with higher levels induced by HSV compared with HIV-1 strains IIIb or BaL. In contrast, the dendritic cells produced detectable protein only for IFN-alpha and IL-6 in response to HIV-1 or HSV, and IL-1beta in response to HSV within 24 h. There were no differences in expression of CD80 and CD86 surface molecules by dendritic cells that were either mock stimulated or stimulated with HIV-1 or HSV for 24 h. Production of IFN-alpha, IL-1beta, and IL-6 by dendritic cells may be important to the immunologic function of these cells and their role in the pathogenesis of HIV-1 and HSV infections.

Cytokine expression by human peripheral blood dendritic cells stimulated in vitro with HIV-1 and herpes simplex virus

Dendritic cells are potent stimulators of Ag-specific T cell responses and have been implicated in the pathogenesis of HIV-1 and other viral infections. Although cytokines may be involved in both of these processes, there is little information on the expression of cytokines by human blood dendritic cells. We characterized cytokine gene and protein expression in dendritic cells that were purified from normal human PBMC by flow cytometry and stimulated in vitro for up to 24 h with HIV-1 or herpes simplex virus (HSV). The unstimulated, uncultured dendritic cells were defined by their phenotype (HLA DR+ CD3- CD19- CD16- CD56- CD14-) and distinct morphology, lack of mRNA expression for CD3, CD14 and CD19, and presence of mRNA for CD4 and CD83. The purified dendritic cells also expressed CD4 (70-90%), CD33 (36-48%), and CD11c (44-54%); lacked CD1a expression (&lt;1%); and were potent stimulators of an allogeneic MLR. The stimulated dendritic cells expressed mRNA for IFN-alpha, IL-1alpha, IL-1beta, IL-6, IL-10, IL-12, GM-CSF, and TNF-alpha within 4 to 12 h as determined by reverse transcription-PCR, with higher levels induced by HSV compared with HIV-1 strains IIIb or BaL. In contrast, the dendritic cells produced detectable protein only for IFN-alpha and IL-6 in response to HIV-1 or HSV, and IL-1beta in response to HSV within 24 h. There were no differences in expression of CD80 and CD86 surface molecules by dendritic cells that were either mock stimulated or stimulated with HIV-1 or HSV for 24 h. Production of IFN-alpha, IL-1beta, and IL-6 by dendritic cells may be important to the immunologic function of these cells and their role in the pathogenesis of HIV-1 and HSV infections.

Selective decrease in human immunodeficiency virus type 1 (HIV-1)-induced alpha interferon production by peripheral blood mononuclear cells during HIV-1 infection

We previously reported that human immunodeficiency virus type 1 (HIV-1), herpes simplex virus (HSV), and Sendai virus induce higher levels of alpha interferon (IFN-alpha) in blood dendritic cells than in monocytes of healthy donors. In the present study, the levels of IFN-alpha induced by T-cell tropic (IIIb and RF) and monocytotropic (BaL) strains of HIV-1 and by HSV were significantly decreased in peripheral blood mononuclear cells (PBMCs) derived from subjects with asymptomatic and symptomatic HIV-1 infection. In contrast, Sendai virus, a paramyxovirus that induces proportionally more IFN-alpha in monocytes and B cells than do either HIV-1 or HSV, stimulated normal levels of IFN-alpha in PBMCs from the HIV-1-infected men. The IFN-alpha produced by PBMCs from the HIV-1-seropositive subjects was partially acid labile, whereas the IFN-alpha produced by PBMCs from the HIV-1-seronegative donors was acid stable. We hypothesize that there is a selective defect in IFN-alpha production by peripheral blood dendritic cells, whereas the host retains the IFN-alpha-producing capacity of monocytes and B lymphocytes. The loss of IFN-alpha production in response to HIV-1, herpesviruses, and possibly other pathogens could contribute to the progression of HIV-1 infection and to the development of AIDS.

[Origin of the right pulmonary artery from the ascending aorta]

A 19-day old female infant presented with congestive cardiac failure. Cardiac catheterization and angiography demonstrated the right pulmonary artery to originate from the ascending aorta, and an atrial septal defect with a left to right shunt of 40%. At the age of six months anastomosis of the right pulmonary artery to the main pulmonary artery was performed with hypothermic arrest and cardioplegia. The postoperative course was complicated by respiratory distress but later the patient's condition improved. Four years later control cardiac catheterization and angiography visualized operative repair and only a small left to right shunt of 20% at atrial level.

[Myocardial revascularization in threatening extension of myocardial infarction (author's transl)]

Myocardial revascularization was performed in 13 patients between two and 14 days following initial infarction because of impending re-infarction. The diagnosis of impending re-infarction was made on the basis of the following criteria: myocardial infarction; repeated stenocardia despite medical treatment; renewed ST-T changes in the ECG. The intra-aortic balloon pump was installed in 7 patients for haemodynamic reasons (shock, massively raised pressure in the pulmonary artery). 12 patients survived the surgical intervention and were eventually discharged free of stenocardia. The presented findings suggest that surgical intervention in impending re-infarction appears of value in those cases which have not been satisfactorily controlled by conventional medical treatment.

[Surgical therapy of postinfarct tachyarrhythmia (author's transl)]

Thirteen patients with ventricular tachyarrhythmias after myocardial infarction underwent surgery at the heart wall or at the coronary vessels. Ten of these patients had an aneurysm of the anterior wall or akinesia of the anterior wall which in some cases was associated with stenosis of the right coronary artery or of the circumflex artery. One patient showed an isolated stenosis of the right coronary artery. One patient died from recurrent ventricular fibrillation during hospitalization, another patient died from reinfarction 4 months later. All the other patients could be discharged and were improved significantly.

Clinical application of the ellipsoid left heart assist device

The ellipsoid left heart assist device (E-LVAD) was implanted in eight patients suffering from intraoperative heart failure. It was not possible to remove these patients from extracorporeal circulation following an intracardiac procedure; therefore, implantation of the E-LVAD was performed during extracorporeal circulation. The inflow connector was pushed forward from a purse-string suture on the right superior pulmonary vein, across the mitral valve and into the left ventricle. The outflow connector was joined to the ascending aorta. In two patients, the artificial heart chamber was removed after complete recovery of the circulation; these patients, however, later died. In six other patients, untreatable right heart failure developed and these patients died with the pump in place. It is concluded, therefore, that the right heart must also be mechanically supported during postoperative heart failure.

[Surgical therapy of varicose veins of the lower limb (author's transl)]

Between 1969 and 1975 302 patients were surgically treated for varicose veins of the lower limbs (bilaterally in 61 cases) in the 2nd Department of Surgery, University of Vienna. 151 patients (including 30 cases operated on bilaterally) were followed up. The "classic" technique of vein stripping introduced by Babcock [1], modified in regard to certain details, was employed. The results of the follow-up examinations are presented and discussed.

The Windkesselventricle with guiding balloon as a new approach for assisted circulation

A simple method was developed to aid the patient with low cardiac output syndrome following cardiac surgery. The concept was shown to be feasible in electric circulatory analog studies and verified in 20 dog experiments. A Dacron graft (end-to-side) through the right second intercostal space connects the ascending aorta to the subcutaneously implanted, ellipsoidal-shaped artifical ventricle. A spherical polyurethane balloon is positioned in the aorta distal to the Dacron graft via the femoral artery. The ventricle and balloon are pneumatically driven synchronously with the ECG. In natural systole the balloon is inflated, occluding the aorta, and the artificial ventricle sucks the entire stroke volume. In natural diastole the balloon deflates and the artificial ventricle ejects the blood into the peripheral arteries. With this system it is possible to maintain a normal systemic pressure and have high hemodynamic efficiency. The left ventricular systolic pressure is 85 percent unloaded. The systolic wave is turned 180 degrees to the natural. After treatment, the device can be removed without thoracotomy.

Late appearance of traumatic ventricular septal defect

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