Venous Return (venous + return)

Distribution by Scientific Domains

Kinds of Venous Return

  • anomalous pulmonary venous return
  • pulmonary venous return


  • Selected Abstracts


    Hemiazygos Venous Additional Pulmonary Flow for Successful Total Cavo-pulmonary Connection

    CONGENITAL HEART DISEASE, Issue 5 2007
    Koichi Sughimoto MD
    ABSTRACT Patients who underwent only Glenn procedure after being deemed unsuitable candidates for Fontan completion are not small in number, and may develop arterio-venous (AV) pulmonary malformations during the follow-up period. We present the case of a 17-year-old woman with severe systemic desaturation 13 years after Glenn procedure and repair of total anomalous pulmonary venous return. Among other anomalies, the patient disclosed hemiazygos continuation to a persistent left superior vena cava. This case supports the concept that returning flow from the abdominal vein plays an important role in the well-balanced growth of the pulmonary artery and in the inhibition of the pulmonary AV malformation. [source]


    Tricuspid Valve Malfunction and Ventricular Pacemaker Lead: Case Report and Review of the Literature

    ECHOCARDIOGRAPHY, Issue 8 2006
    Said B. Iskandar M.D.
    Pacemaker implantation can be associated with several complications, including myocardial perforation with or without pericardial effusion, venous thrombosis, vegetations of the tricuspid valve (TV) or pacing lead, and tricuspid regurgitation (TR). The TR is thought to be derived from deformity or perforation of the TV by the pacing lead or secondary to atrioventricular discordance with asynchronous ventricular pacing. Severe TR can be deleterious to the patient because it raises the central venous pressure by increasing the right sided preload. Chronically, the increase in right sided blood volume can result in an increase in the right atrial pressure leading to a decrease in venous return and low cardiac output. Severe TR from leaflet adhesion to the pacemaker lead has not been reported before. With the aging of the population and the expanding use of pacemakers and implantable cardioverter defibrillators (ICD) in clinical practice, this complication may be seen more frequently. We present a patient diagnosed with severe TR, years after his pacemaker implantation. His TR was thought to be caused by adhesion of the tricuspid valve to his pacemaker lead. [source]


    Localization of the mosaic transmembrane serine protease corin to heart myocytes

    FEBS JOURNAL, Issue 23 2000
    John D. Hooper
    Corin cDNA encodes an unusual mosaic type II transmembrane serine protease, which possesses, in addition to a trypsin-like serine protease domain, two frizzled domains, eight low-density lipoprotein (LDL) receptor domains, a scavenger receptor domain, as well as an intracellular cytoplasmic domain. In in vitro experiments, recombinant human corin has recently been shown to activate pro-atrial natriuretic peptide (ANP), a cardiac hormone essential for the regulation of blood pressure. Here we report the first characterization of corin protein expression in heart tissue. We generated antibodies to two different peptides derived from unique regions of the corin polypeptide, which detected immunoreactive corin protein of approximately 125,135 kDa in lysates from human heart tissues. Immunostaining of sections of human heart showed corin expression was specifically localized to the cross striations of cardiac myocytes, with a pattern of expression consistent with an integral membrane localization. Corin was not detected in sections of skeletal or smooth muscle. Corin has been suggested to be a candidate gene for the rare congenital heart disease, total anomalous pulmonary venous return (TAPVR) as the corin gene colocalizes to the TAPVR locus on human chromosome 4. However examination of corin protein expression in TAPVR heart tissue did not show evidence of abnormal corin expression. The demonstrated corin protein expression by heart myocytes supports its proposed role as the pro-ANP convertase, and thus a potentially critical mediator of major cardiovascular diseases including hypertension and congestive heart failure. [source]


    Prevention of hemodialysis-related muscle cramps by intradialytic use of sequential compression devices: A report of four cases

    HEMODIALYSIS INTERNATIONAL, Issue 3 2004
    Muhammad Ahsan
    Background:, Hemodialysis (HD)-related lower extremity (LE) muscle cramps are a common cause of morbidity in end-stage renal disease patients on maintenance HD. Numerous pharmacologic and physical measures have been tried with variable success rates. Methods:, Sequential compression devices (SCD) improve venous return (VR) and are commonly used to prevent LE deep venous thrombosis in hospitals. We hypothesized that LE cramps are triggered by stagnant venous flow during HD and are preventable by improving VR. We prospectively studied four adult patients (mean age 61 ± 14 years) on thrice-weekly HD who experienced two or more episodes of LE cramping weekly in the month before the study. SCD were applied before each HD on both legs and compressions were intermittently applied at 40 mmHg during treatment. Results:, All four patients reported complete resolution of cramping during the study period that lasted 1 month or 12 consecutive dialysis treatments. Conclusion:, Application of SCD to LE may prevent the generation of LE HD-related cramping in a select group of patients. Larger, controlled studies are needed to establish the utility of this noninvasive alternative for the prevention of LE HD-related cramps. [source]


    Regulatory processes interacting to maintain hepatic blood flow constancy: Vascular compliance, hepatic arterial buffer response, hepatorenal reflex, liver regeneration, escape from vasoconstriction

    HEPATOLOGY RESEARCH, Issue 11 2007
    W. Wayne Lautt
    Constancy of hepatic blood flow (HBF) is crucial for several homeostatic roles. The present conceptual review focuses on interrelated mechanisms that act to maintain a constant HBF per liver mass. The liver cannot directly control portal blood flow (PF); therefore, these mechanisms largely operate to compensate for PF changes. A reduction in PF leads to reduced intrahepatic distending pressure, resulting in the highly compliant hepatic vasculature passively expelling up to 50% of its blood volume, thus adding to venous return, cardiac output and HBF. Also activated immediately upon reduction of PF are the hepatic arterial buffer response and an HBF-dependent hepatorenal reflex. Adenosine is secreted at a constant rate into the small fluid space of Mall which surrounds the terminal branches of the hepatic arterioles, portal venules and sensory nerves. The concentration of adenosine is regulated by washout into the portal venules. Reduced PFreduces the washout and the accumulated adenosine causes dilation of the hepatic artery, thus buffering the PF change. Adenosine also activates hepatic sensory nerves to cause reflex renal fluid retention, thus increasing circulating blood volume and maintaining cardiac output and PF. If these mechanisms are not able to maintain total HBF, the hemodynamic imbalance results in hepatocyte proliferation, or apoptosis, by a shear stress/nitric oxide-dependent mechanism, to adjust total liver mass to match the blood supply. These mechanisms are specific to this unique vascular bed and provide an excellent example of multiple integrative regulation of a major homeostatic organ. [source]


    Left Superior Vena Cava Draining into the Left Atrium, Associated with Partial Anomalous Pulmonary Venous Connection: Surgical Correction

    JOURNAL OF CARDIAC SURGERY, Issue 4 2005
    Andrea Quarti M.D.
    Although intra-atrial rerouting techniques, in patients with no connecting vein, have proved to be reliable and successful, in many cases the extracardiac repair is preferable. We report a case of a 5-month-old patient with a not connected left superior vena cava draining into the left atrium, associated with atrial septal defect and partial anomalous pulmonary venous connection. The correction has been achieved by rerouting the pulmonary venous return into the left atrium and by transposition of the left vena cava on the right appendage. [source]


    Sonographically guided percutaneous sclerosis using 1% polidocanol in the treatment of vascular malformations

    JOURNAL OF CLINICAL ULTRASOUND, Issue 7 2002
    Rajeev Jain MD
    Abstract Purpose The aim of this prospective study was to assess the safety and efficacy of sonographically guided percutaneous injection of 1% polidocanol for sclerosis of peripheral vascular malformations. Methods Patients with vascular malformations of soft tissues were invited to enroll in the study. Gray-scale and color Doppler sonography were performed to determine the texture, margins, and size of the lesions and to determine whether high-velocity blood flow was present. Using real-time sonographic guidance, lesions were punctured with a 20/21-gauge spinal needle. When possible, venous return was occluded before injection. For each injection, 1,6 ml of 1% polidocanol was injected into 1 or more sites within the lesion. The sclerosing agent was not aspirated after injection. Repeat radiography was performed 1 month after each injection session. The procedure was repeated if the patient did not have a complete response, defined as an 80% or greater decrease in the volume of the lesion or resolution of the presenting symptoms. Results Of the 15 patients enrolled, 9 had venous malformations, 3 had lymphangiomas, 1 had a recurrent aneurysmal bone cyst, 1 had a venous pseudoaneurysm, and 1 had an arteriovenous malformation of the pinna. Each patient received 1,20 injections of 1% polidocanol (mean ± standard deviation, 3.3 ± 4.8 injections). This treatment resulted in a complete response of 7 venous malformations, 3 lymphangiomas, and the arteriovenous malformation and partial response of 2 venous malformations, the recurrent aneurysmal bone cyst, and the venous pseudoaneurysm. Only minor complications occurred. Conclusions Sonographically guided percutaneous injection of 1% polidocanol for sclerosis of peripheral vascular lesions is simple, effective, and safe. This technique is especially effective in cases of soft tissue venous malformation and lymphangioma. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:416,423, 2002 [source]


    MRI of partial anomalous pulmonary venous return (scimitar syndrome)

    JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 1 2003
    M Puvaneswary
    Summary We report a case of anomalous pulmonary venous drainage into the inferior vena cava (scimitar syndrome). Cine MRI and 3-D contrast-enhanced MR angiography provides an non-invasive diagnostic technique in the evaluation of anomalous pulmonary venous return. [source]


    Importance of Anterograde Visualization of the Coronary Venous Network by Selective Left Coronary Angiography Prior To Resynchronization

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2007
    NICOLAS DELARCHE M.D.
    Background: Understanding of coronary anatomy is essential to the advancement of cardiac resynchronization therapy (CRT) techniques. We determined whether the difficulties associated with catheterization of the coronary sinus (CS) and its lateral branches could be overcome by a preliminary angiographical study of the coronary venous system carried out during a pre-operative coronary angiography with examination of venous return. Methods and Results: All patients were scheduled for an exploratory angiography procedure and indicated for CRT. Group A patients were implanted with a CRT device after a right arterial angiographical procedure while group B patients had a selective left angiogram including examination of venous return. Data analyzed in group B were: position of CS ostium, number and distribution of lateral branches, and ability to preselect a marginal vein suitable for catheterization. Subsequent device implantation was guided by these parameters. A total of 96 and 89 patients were included in groups A and B, respectively. Implantation success rates were not different (98% and 100%, respectively), but CS catheterization time was reduced in group B (6 minutes vs 4 minutes; P < 10,6) as well as total time required to position the left ventricular lead (25 minutes vs 15 minutes; P < 10,6), fluoroscopy exposure (7 minutes vs 5 minutes; P < 10,6), and volume of contrast medium required (45 mL vs 15 mL; P < 10,6). Conclusion: A coronary angiographical study, including examination of the coronary venous return prior to implantation of a CRT device, can simplify the device implant and allows patient-specific preselection of appropriate tools for the procedure. [source]


    Haemodynamic responses to exercise, ATP infusion and thigh compression in humans: insight into the role of muscle mechanisms on cardiovascular function

    THE JOURNAL OF PHYSIOLOGY, Issue 9 2008
    José González-Alonso
    The muscle pump and muscle vasodilatory mechanims are thought to play important roles in increasing and maintaining muscle perfusion and cardiac output during exercise, but their actual contributions remain uncertain. To evaluate the role of the skeletal muscle pump and vasodilatation on cardiovascular function during exercise, we determined leg and systemic haemodynamic responses in healthy men during (1) incremental one-legged knee-extensor exercise, (2) step-wise femoral artery ATP infusion at rest, (3) passive exercise (n= 10), (4) femoral vein or artery ATP infusion (n= 6), and (5) cyclic thigh compressions at rest and during passive and voluntary exercise (n= 7). Incremental exercise resulted in progressive increases in leg blood flow (,LBF 7.4 ± 0.7 l min,1), cardiac output ( 8.7 ± 0.7 l min,1), mean arterial pressure (,MAP 51 ± 5 mmHg), and leg and systemic oxygen delivery and . Arterial ATP infusion resulted in similar increases in , LBF, and systemic and leg oxygen delivery, but central venous pressure and muscle metabolism remained unchanged and MAP was reduced. In contrast, femoral vein ATP infusion did not alter LBF, or MAP. Passive exercise also increased blood flow (,LBF 0.7 ± 0.1 l min,1), yet the increase in muscle and systemic perfusion, unrelated to elevations in aerobic metabolism, accounted only for ,5% of peak exercise hyperaemia. Likewise, thigh compressions alone or in combination with passive exercise increased blood flow (,LBF 0.5,0.7 l min,1) without altering , MAP or . These findings suggest that the skeletal muscle pump is not obligatory for sustaining venous return, central venous pressure, stroke volume and or maintaining muscle blood flow during one-legged exercise in humans. Further, its contribution to muscle and systemic peak exercise hyperaemia appears to be minimal in comparison to the effects of muscle vasodilatation. [source]


    Fully Autonomous Preload-Sensitive Control of Implantable Rotary Blood Pumps

    ARTIFICIAL ORGANS, Issue 9 2010
    Andreas Arndt
    Abstract A pulsatility-based control algorithm with a self-adapting pulsatility reference value is proposed for an implantable rotary blood pump and is to be tested in computer simulations. The only input signal is the pressure difference across the pump, which is deduced from measurements of the pump's magnetic bearing. A pulsatility index (PI) is calculated as the mean absolute deviation from the mean pressure difference. As a second characteristic, the gradient of the PI with respect to the pump speed is derived. This pulsatility gradient (GPI) is used as the controlled variable to adjust the operating point of the pump when physiological variables such as the systemic arterial pressure, left ventricular contractility, or heart rate change. Depending on the selected mode of operation, the controller is either a linear controller or an extremum-seeking controller. A supervisory mechanism monitors the state of the system and projects the system into the region of convergence when necessary. The controller of the GPI continuously adjusts the reference value for PI. An underlying robust linear controller regulates the PI to the reference value in order to take into account changes in pulmonary venous return. As a means of reacting to sudden changes in the venous return, a suction detection mechanism was included. The control system is robustly stable within a wide range of physiological variables. All the clinician needs to do is to select between the two operating modes. No other adjustments are required. The algorithm showed promising results which encourage further testing in vitro and in vivo. [source]


    Left Ventricle Afterload Impedance Control by an Axial Flow Ventricular Assist Device: A Potential Tool for Ventricular Recovery

    ARTIFICIAL ORGANS, Issue 9 2010
    Francesco Moscato
    Abstract Ventricular assist devices (VADs) are increasingly used for supporting blood circulation in heart failure patients. To protect or even to restore the myocardial function, a defined loading of the ventricle for training would be important. Therefore, a VAD control strategy was developed that provides an explicitly definable loading condition for the failing ventricle. A mathematical model of the cardiovascular system with an axial flow VAD was used to test the control strategy in the presence of a failing left ventricle, slight physical activity, and a recovering scenario. Furthermore, the proposed control strategy was compared to a conventional constant speed mode during hemodynamic changes (reduced venous return and arterial vasoconstriction). The physiological benefit of the control strategy was manifested by a large increase in the ventricular Frank,Starling reserve and by restoration of normal hemodynamics (5.1 L/min cardiac output at a left atrial pressure of 10 mm Hg vs. 4.2 L/min at 21 mm Hg in the unassisted case). The control strategy automatically reduced the pump speed in response to reduced venous return and kept the pump flow independent of the vasoconstriction condition. Most importantly, the ventricular load was kept stable within 1%, compared to a change of 75% for the constant speed. As a key feature, the proposed control strategy provides a defined and adjustable load to the failing ventricle by an automatic regulation of the VAD speed and allows a controlled training of the myocardium. This, in turn, may represent a potential additional tool to increase the number of patients showing recovery. [source]


    A Passively Controlled Biventricular Support Device

    ARTIFICIAL ORGANS, Issue 6 2010
    Nicholas Richard Gaddum
    Abstract Clinical studies have reported the balancing of pump outputs to be a serious control issue for rotary biventricular support (BiVS) systems. Poor reliability of long-term, blood immersed pressure sensors encouraged the development of a new control strategy to improve their viability. A rotary BiVS device was designed and constructed with a mechanical passive controller to autoregulate pump outputs to emulate the native baroreceptor response. In vitro testing in a dual circuit, hydraulic mock circulation loop showed that the prototype was able to maintain arterial pressures when subjected to sudden induced hemodynamic destabilization. However, inlet suction was observed when sudden simulated hypertension briefly reduced venous return to the cannulated ventricle. The results have encouraged further development of the device as a means to create an inherently stable, fully passive biventricular support device. [source]


    Physiological Control of a Rotary Blood Pump With Selectable Therapeutic Options: Control of Pulsatility Gradient

    ARTIFICIAL ORGANS, Issue 10 2008
    Andreas Arndt
    Abstract A control strategy for rotary blood pumps meeting different user-selectable control objectives is proposed: maximum support with the highest feasible flow rate versus medium support with maximum ventricular washout and controlled opening of the aortic valve (AoV). A pulsatility index (PI) is calculated from the pressure difference, which is deduced from the axial thrust measured by the magnetic bearing of the pump. The gradient of PI with respect to pump speed (GPI) is estimated via online system identification. The outer loop of a cascaded controller regulates GPI to a reference value satisfying the selected control objective. The inner loop controls the PI to a reference value set by the outer loop. Adverse pumping states such as suction and regurgitation can be detected on the basis of the GPI estimates and corrected by the controller. A lumped-parameter computer model of the assisted circulation was used to simulate variations of ventricular contractility, pulmonary venous pressure, and aortic pressure. The performance of the outer control loop was demonstrated by transitions between the two control modes. Fast reaction of the inner loop was tested by stepwise reduction of venous return. For maximum support, a low PI was maintained without inducing ventricular collapse. For maximum washout, the pump worked at a high PI in the transition region between the opening and the permanently closed AoV. The cascaded control of GPI and PI is able to meet different control objectives and is worth testing in vitro and in vivo. [source]


    Parental lead exposure and total anomalous pulmonary venous return

    BIRTH DEFECTS RESEARCH, Issue 4 2004
    Leila W. Jackson
    Abstract BACKGROUND Investigators from the Baltimore-Washington Infant Study (BWIS) reported an association between self-reported maternal lead exposure and total anomalous pulmonary venous return (TAPVR) in their offspring. This association was further evaluated in the BWIS population using a more sensitive exposure estimate. METHODS Cases included 54 live-born infants with TAPVR; controls were a stratified random sample of 522 live-born infants from the BWIS control group. Parental lead exposure was based on three assessment methods, including: an industrial hygiene assessment, an a priori job exposure matrix, and self-reported exposures. A parent was classified as exposed to lead if he/she was classified as exposed by any one of the assessment methods. RESULTS Approximately 17% of case mothers and 11% of control mothers were classified as exposed to lead during the three months prior to conception through the first trimester (odds ratio [OR], 1.57; 95% confidence interval [CI], 0.64,3.47). Among fathers, 61% of case fathers and 46% of control fathers were classified as exposed to lead during the six months prior to conception (paternal critical period) (OR, 1.83; 95% CI, 1.00,3.42). During the paternal critical period, when only the father was exposed compared to neither parent exposed, the OR for any lead exposure and TAPVR was 1.65 (95% CI, 0.84,3.25). CONCLUSIONS This study supports a possible association between paternal lead exposure and TAPVR. Further studies are warranted using validated assessment methods for occupational and nonoccupational lead exposures to corroborate this association and to elucidate the possible biological mechanism. Birth Defects Research (Part A), 2004. © 2004 Wiley-Liss, Inc. [source]


    Specific congenital heart defects in RSH/Smith-Lemli-Opitz syndrome: Postulated involvement of the Sonic Hedgehog pathway in syndromes with postaxial polydactyly or heterotaxia

    BIRTH DEFECTS RESEARCH, Issue 3 2003
    Maria Cristina Digilio
    BACKGROUND RSH/Smith-Lemli-Opitz syndrome is an autosomal recessive syndrome due to an inborn error of cholesterol metabolism and is characterized by developmental delay, facial anomalies, hypospadias, congenital heart defect (CHD), postaxial polydactyly, and 2,3 toe syndactyly. CHD is found in half of the propositi, and a specific association with atrioventricular canal defect (AVCD) and anomalous pulmonary venous return has been demonstrated. METHODS We report on an additional patient with RSH/SLOS presenting with complete AVCD and anomalous pulmonary venous return, and discuss the possible relationship of the Sonic Hedgehog (SHH) pathway as causative factor of these CHDs and those in heterotaxia patients with postaxial polydactyly syndromes. RESULTS Anatomic similarities between heterotaxia and CHDs of several syndromes with postaxial polydactyly have been noted previously, considering the frequent association of AVCD with common atrium in these conditions. It is known that both CHDs of heterotaxia and postaxial polydactyly can be related to abnormalities of the SHH pathway. Cholesterol has a critical role in the formation of normally active hedgehog proteins. It could be hypothesized that specific types of CHDs in RSH/SLOS can be caused by modifications of the SHH protein related to the defect of cholesterol biosynthesis. CONCLUSIONS The specific association of AVCD and anomalous pulmonary venous return in patients with RSH/SLOS and the finding of AVCD ± common atrium in several syndromes with polydactyly leads to the hypothesis that heterotaxia due to SHH anomalies could be involved in a large spectrum of conditions. Perturbations in different components of the SHH pathway could lead to several developmental errors presenting with partially overlapping clinical manifestations. Birth Defects Research (Part A) 67149,153, 2003. © 2003 Wiley-Liss, Inc. [source]


    Look before you close: Atrial septal defect with undiagnosed partial anomalous pulmonary venous return

    CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2005
    David T. Cragun MD
    Abstract The growing and continued success of percutaneous closure of atrial defects is related to its high benefit-to-risk ratio in appropriately selected patients. The following case illustrates a previously undocumented danger, namely, the potential for incomplete correction. A thorough transesophageal examination performed at the time of the planned atrial defect closure suggested the presence of a partial anomalous pulmonary vein insertion, which was then appropriately documented and the incomplete closure was averted. © 2005 Wiley-Liss, Inc. [source]


    Acute left ventricular failure after large volume pericardiocentesis

    CLINICAL CARDIOLOGY, Issue 12 2003
    A. Chamoun M.D.
    Abstract This paper reports on two cases of large volume pericardiocentesis followed by transient severe acute left ventricular (LV) systolic failure in the absence of any prior history of LV dysfunction. Acute LV volume overload due to inter-ventricular volume mismatch is believed by most authors to be the cause for this phenomenon. Another plausible physiopathologic explanation is the acute increase in "wall stress" (Laplace's law) due to acute distention of the cardiac chambers secondary to a sudden increase in venous return at high filling pressures, combined with a "vacuum" effect of the evacuated pericardial space. [source]


    Asystole and increased serum myoglobin levels associated with ,packing blackout' in a competitive breath-hold diver

    CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 6 2009
    Johan P. A. Andersson
    Summary Many competitive breath-hold divers use ,glossopharyngeal insufflation', also called ,lung packing', to overfill their lungs above normal total lung capacity. This increases intrathoracic pressure, decreases venous return, compromises cardiac pumping, and reduces arterial blood pressure, possibly resulting in a syncope breath-hold divers call ,packing blackout'. We report a case with a breath-hold diver who inadvertently experienced a packing blackout. During the incident, an electrocardiogram (ECG) and blood pressure were recorded, and blood samples for determinations of biomarkers of cardiac muscle perturbation (creatine kinase-MB isoenzyme (CK-MB), cardiac troponin-T (TnT), and myoglobin) were collected. The ECG revealed short periods of asystole during the period of ,packing blackout', simultaneous with pronounced reductions in systolic, diastolic, and pulse pressures. Serum myoglobin concentration was elevated 40 and 150 min after the incident, whereas there were no changes in CK-MB or TnT. The ultimate cause of syncope in this diver probably was a decrease in cerebral perfusion following glossopharyngeal insufflation. The asystolic periods recorded in this diver could possibly indicate that susceptible individuals may be put at risk of a serious cardiac incident if the lungs are excessively overinflated by glossopharyngeal insufflation. This concern is further substantiated by the observed increase in serum myoglobin concentration after the event. [source]


    Rowing, the ultimate challenge to the human body , implications for physiological variables

    CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 4 2009
    Stefanos Volianitis
    Summary Clinical diagnoses depend on a variety of physiological variables but the full range of these variables is seldom known. With the load placed on the human body during competitive rowing, the physiological range for several variables is illustrated. The extreme work produced during rowing is explained by the seated position and the associated ability to increase venous return and, thus, cardiac output. This review highlights experimental work on Olympic rowing that presents a unique challenge to the human capacities, including cerebral metabolism, to unprecedented limits, and provides a unique opportunity to reveal the extreme range of many physiological variables. [source]


    Remnant liver regeneration and spleen volume changes after living liver donation: influence of the middle hepatic vein

    CLINICAL TRANSPLANTATION, Issue 6 2006
    Tai-Yi Chen
    Abstract:, Background and objectives:, Graft harvest with or without the middle hepatic vein (MHV) affects venous return and function of the remaining liver. The aims of this study are to compare the remnant liver volume and spleen changes in the donors of different types of graft harvest and to evaluate the influence of resection with or without the MHV on the remnant liver volume regeneration, spleen volume change and serum total bilirubin. Patients and methods: A total of 165 donors were grouped according to the type of graft harvest: 88 donors underwent left lateral segmentectomy (LLS), 10 donors underwent extend LLS or left lobectomy (LL), and 67 donors underwent right lobectomy (RL). Groups LLS and LL were later combined as group LH (left hepatectomy, n = 98). There were 68 men and 97 women. The mean age was 32.9 ± 8.1 yr. The total liver volume (LV) and spleen volume (S1) before graft harvest, graft weight (GW), regenerated liver volume (LV6m) and spleen volume (S2) six months post-donation were calculated. Results:, There were no significant differences in the regenerated liver volume six months postoperation (LV6m) and recovery ratio (LV6m/LV × 100%) among the different groups, albeit significant smaller LV6m in both groups compared with the initial liver volume was noted. Postoperative spleen volume (S2), average spleen ratio (S2/S1) and spleen change ratio were significantly larger and higher in group RL than in group LH. A significant increase in spleen volume was noted in both groups six months after graft harvest. A significantly higher TB in group RL (4.1 ± 1.7 mg/dL, range: 1.4,8.5 mg/dL) was noted compared with that of group LH (1.6 ± 1.0 mg/dL, range: 0.7,6.2 mg/dL). Conclusion: There was a significant increase in the regenerated remnant liver and splenic volumes six months postoperation in all types of hepatectomy following living donor hepatectomy, and there was no difference in the mean TB levels among donors whether the MHV was included or not in the graft. [source]