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Biomedical subjects

G Bruschi

Publications and source records attributed to G Bruschi.

At least 19 recordsLinked to original sources

Materials characterization of explanted mechanical heart valves and comparison to patients' clinical data.

In the present study, twelve explanted mechanical heart valves (MHVs)with pyrolitic carbon tilting disc and 14 bileaflet MHVs were analyzed to investigate the effects of material properties on valve performance and patients' general health conditions. Optical and scanning electron microscopy was used to investigate material imperfections, wear patterns or damages to housing and occluder components. All analyzed tilting disc valves exhibited wear effects, particularly due to abrasion and impact to both disc and housing. Wear of pyrolitic carbon disc and housing did not influence their in vivo performance. In the bileaflet MHVs, breakaway of the pyrolitic carbon coating sometimes caused malfunctioning and required surgical retrieval of the valve. In all cases, occurrence of clinical symptoms was more likely when wear effects were located in critical areas. The study supports a correlation between the properties of the MHVs material and patients' symptoms.

Adult↗

Mechanical circulatory support in severe heart failure: single-center experience.

Ventricular assist devices (VADs) have become important therapeutic tools to treat patients with end-stage cardiac failure. VADs are an essential component of transplantation programs as they successfully bridge individuals who would otherwise die. Recently left ventricular VAD (LVAD) therapy has been proposed as alternative to heart transplantation (HTx) for patients who are not transplant candidates. Other indications have now expanded into areas such as postcardiotomy failure, acute myocarditis, and acute massive myocardial infarction. From 1988 to May 2003, 80 patients received left or biventricular mechanical circulatory support including 78 as a bridge to and two as an alternative to HT. All patients survived the operation. Mean duration of VAD support was 77 +/- 150 days. Fifty-one points (63.8%) underwent heart transplantation; 3 (3.8%) recovered and were weaned from VADs. Major bleeding episodes occurred in 11 patients (13.8%) and major neurologic events occurred in 8 (10%). Sixteen patients (20%) were discharged home while waiting for HTx. Twenty-two patients (27.5%) died on VAD. In conclusion, VAD therapy proved effective in bridging patients with end-stage heart failure to HTx. While on LVAD support patients who were assisted with implantable wearable devices could be discharged at home, improving their quality of life.

Cause of Death↗

Impella recover 100 microaxial left ventricular assist device: the Niguarda experience.

BACKGROUND: The Impella Recover 100 (IR100) is an intravascular microaxial blood pump used to support blood circulation for a maximum of 7 days in cases of reduced left ventricular function, for example in postcardiotomy low output syndrome or in cardiogenic shock after acute myocardial infarction. MATERIALS AND METHODS: We supported five patients with the IR100. The mean age, cardiac index (CI), and ejection fraction (EF) of our population were 42 years, 1.83 L/min/m(2), and 20%, respectively. Two patients (group A) with ischemic dilated cardiomyopathy were bridged to heart transplant. Two patients (group B) with fulminan myocarditis and septic shock were bridged to recovery. One patient, with severe valvular cardiomyopathy who underwent aortic valve replacement and mitral valve annuloplasty, was supported to weaning from ECC. RESULTS: Mean support time was 9.8 +/- 2.3 days. Only one acute myocarditis patient died from a severe vasoplegic syndrome despite maximal inotropic and vasoactive support. Both group A patients were successfully transplanted. Among group B, the second patient resolved the septic status and was slowly weaned from the device and discharged home with moderate improvement of LV function (EF = 40%). Patient C was weaned from the IR100 and electively placed on the heart transplant recipient list. CONCLUSIONS: IR100 is a device that in our experience can be utilized for various indications for short-term support. In compromised patients where a traditional LVAD is contraindicated, the IR100 showed good results, for it is minimally invasive and does not need ECC or systemic anticoagulation.

Equipment Design↗

Combined surgical approach to coexistent carotid and coronary artery disease: early and late results.

BACKGROUND: The management of patients with simultaneous coronary artery and carotid artery disease is still controversial. METHODS: A retrospective review of the records and follow-up data of 139 consecutive patients undergoing simultaneous coronary artery bypass graft and carotid endarterectomy from 1981 to 1999 was carried out. RESULTS: Early mortality was 2.1%, perioperative myocardial infarction and stroke rates were 2.8 and 1.4%, respectively. Survival at 7 years was 74.7+/-5.1% and event-free survival at 7 years was 67.9+/-5.6%. CONCLUSIONS: The combined surgical approach has proved to be effective and safe allowing the treatment of both diseases in a single operative procedure.

Aged↗

Aorto-atrial fistula through the septum in recurrent aortic dissection.

A case of aortic dissection (De Bakey type I) with a fistula to the right atrium through the interatrial septum, diagnosed by transthoracic and transesophageal echocardiography is reported. The patient presented with cardiac failure and a continuous murmur in the right second and third intercostal spaces. The patient underwent successful operative repair.

Aged↗

Topoisomerase I inhibitors combination chemotherapy in non-small cell lung cancer.

In the last years, the main topoisomerase I inhibitors (TP1-I) (i.e. topotecan and irinotecan) have been used in combination chemotherapy in non-small cell lung cancer. Several drugs (also alternative to cisplatin) have been used in combination with TP1-I, but to date the higher remission rate obtained with combinations is not translated into a more prolonged survival in comparison with TP1-I given alone. On the other hand, the toxicity of TP1-I combinations is greater than those of TP1-I used alone. The superior efficacy of combinations versus TP1-I used alone remains an open question. Furthermore, the best schedule for TP1-I has not been completely elucidated. Randomised studies are few (only two phase III trials) and only controlled studies will be able to clarify the best TP1-I combination regimen.

Antineoplastic Agents↗

Tricuspid regurgitation secondary to mitral valve disease: tricuspid annulus function as guide to tricuspid valve repair.

METHODS: A prospective analysis was performed on 50 patients (pts) with rheumatic mitral disease and associate secondary tricuspid insufficiency who underwent mitral valve replacement from January 1995 to December 1998. Surgical indication to tricuspid annuloplasty was considered in patients with echocardiographic tricuspid annulus diameter > 21 mm/m2, regardless semiquantitative evaluation of tricuspid insufficiency. De Vega annuloplasty was performed in 33 out of 50 patients. RESULTS: Hospital mortality was 2.0% (CL 0.3-3.6). The follow up of the discharged patients ranged from 3 to 48 months (mean 25 +/- 15.9). Three late deaths occurred (6.1% CL 2.8-9.2). Forty-two patients out of the 46 followed up (91.3% CL 84.9-93.8) were in I or II NYHA class. In eight patients (16.3% of discharged patients) the obtained result has been considered as 'negative late results': persisting moderate (three cases) or moderate-severe (five cases) TrI, together with congestive heart failure requiring a furosemide intake of > 25 mg/day. No patients had severe TrI at follow up. The statistics analysis demonstrated the 'preoperative fraction shortening of the tricuspid annulus' (P = 0.038) as factor predictive of late negative result. The incidence of late negative result was 57.1% among patients with fractional shortening lower than 25% and 0% among those patients with fractional shortening greater than 25% (P = 0.0001). CONCLUSIONS: The choice to treat the tricuspid insufficiency according to indexed tricuspid annulus dimension (> 21 mm/m2) has been effective in terms of clinical efficacy and of late functional result. Fractional shortening of the tricuspid annulus, expression of right ventricular cardiomyopathy in patients with poorest prognosis, affects the postoperative evolution of tricuspid insufficiency.

Adult↗

Papillary muscle rupture and pericardial injuries after blunt chest trauma.

Non-penetrating cardiac trauma resulting in mitral valve rupture is uncommon, requiring a high degree of suspicion for diagnosis. Sudden and severe mitral regurgitation, unless surgically corrected rapidly lead to congestive heart failure and death. We report a patient with traumatic rupture of the antero-lateral papillary muscle of the mitral valve and pericardial injury, after a lateral blunt chest trauma, who successfully underwent emergency mitral valve replacement.

Adult↗

First successful Italian clinical experience with DeBakey VAD.

The growing number of patients waiting for heart transplantation more than tripled between 1989 and 1998. Various non-pulsatile mechanical circulatory support devices have been developed as bridge to heart transplantation in recent years. We report the first successful Italian clinical experience with an axial-flow pump, DeBakey VAD, in a patient supported as bridge to transplantation for 55 days.

Cardiomyopathy, Dilated↗

Doppler tissue echocardiography: myocardial wall motion velocities in essential hypertension.

AIMS: Doppler tissue echocardiography (DTE) was applied to extract the myocardial wall velocities along different planes and evaluate the left ventricular function in essential hypertension. METHODS AND RESULTS: Fifty-four hypertensives (HT) were compared to a control group of 31 normotensive (NT) subjects. The short-axis shortening and lengthening was assessed through the parasternal projections, sampling from interventricular septum and posterior wall. Through the apical projections the mitral annulus excursion was observed at four sites (anterior, posteroseptal, lateral, inferior walls) to assess the longitudinal dynamic of the heart. In each myocardial segment, peak velocity and time-velocity integral for systolic (S) and diastolic waves (E and A) were measured and their means for the long- and short-axis directions were calculated. Significant changes in hypertensives involved mainly the longitudinal motion. In diastole, the E-wave relaxation velocity was significantly decreased and the late A-wave velocity was unchanged. The E/A velocity ratio was significantly reduced. Relaxation velocity was negatively correlated to age, left ventricular mass and diastolic blood pressure. In systole, the peak S-wave shortening velocity was reduced and no association with age, left ventricular mass and blood pressure could be demonstrated. The range of segmental data produced by DTE proved useful to manufacture sensitive indices for recognition of hypertensive damage. Single DTE variables also proved slightly more sensitive than those extracted from the mitral flow pattern for the discrimination of HT patients. CONCLUSION: The presence of impaired relaxation was confirmed by DTE in a large portion of patients with hypertension and left ventricular hypertrophy. A peculiar systolic disturbance is evidenced by this technique. DTE-derived information can be used to detect early and quantify target-organ damage and its progression or regression during antihypertensive treatment.

Adult↗

[Left monoventricular assistance with DeBakey VAD continuous flow pump: initial clinical Italian experience].

BACKGROUND: The shortage of heart donors causes a rise in mortality among candidates for cardiac transplantation and increases the waiting list. Consequently mechanical circulatory support for bridge to transplant is now a standard clinical procedure utilized in the most representative cardiac surgery centers. Recently, continuous-axial-flow pumps have been introduced in the clinical practice and have led to new perspectives. METHODS: Four patients suffering from end-stage heart failure were implanted with a DeBakey ventricular assist device (VAD) continuous-flow pump as a bridge to heart transplant. The DeBakey VAD is smaller than the pulsatile devices commonly employed, the pump is totally implantable and is connected to a small controller and two batteries by a transcutaneous drive line. RESULTS: One patient died of multiorgan failure during assistance; 3 patients were fully rehabilitated and were successfully transplanted after 55, 42 and 141 days respectively. In the early postoperative period the mean pump flow was 4.27 +/- 0.55 l/min, after 1 week of assistance the flow rose to 5.32 +/- 0.57 l/min and then progressively increased to 5.83 +/- 0.57 l/min. CONCLUSIONS: This experience demonstrated the possibility of continuous-flow left ventricular support with the DeBakey VAD for mid-term mechanical ventricular assistance. This pump presents new interesting aspects and opens new perspectives for the future of left ventricular mechanical assistance. Increasing experience will define the role of this device in the scenario of heart failure.

Adult↗

Modified pericardial closure technique in patients with ventricular assist device.

The use of Gore-Tex (W.L. Gore & Assoc, Flagstaff, AZ) sheet for pericardial closure in patients with left ventricular assist device as a bridge to transplant allows easy dissection of epicardial adhesions and safe resternotomy at the moment of heart transplantation, with no complications or significant cost increase related to the Gore-Tex itself.

Heart-Assist Devices↗

Regional sympathetic activity in pre-hypertensive phase of spontaneously hypertensive rats.

Imbalances in central and peripheral sympathetic nervous system (SNS) activity have been observed in essential and experimental hypertension. This study was carried out in order to evaluate SNS activity in two distinct tissue types of spontaneously hypertensive rats (SHR), compared to Wistar-Kyoto normotensive (WKY) rats, in the pre-hypertensive phase (4-5 weeks of age). Interstitial concentrations of norepinephrine (NE) and other catecholamines were measured by microdialysis in striated muscle, whose tone is controlled by baroreflexes, and in the subcutaneous adipose tissue where sympathetic output mainly controls metabolism. Two groups of SHR and WKY male rats were studied, aged 4-5 weeks, with a mean body weight of 92 and 86 g respectively. Systolic blood pressure (SBP, tail-cuff) values were 113 mm Hg (SD +/- 6.2) in SHR and 108 mm Hg (SD +/- 7.3) in WKY rats (p=0.28,t test). Two microdialysis probes were positioned in the subcutaneous fatty tissue and in the striated muscle of the parascapular region and perfused with Ringers' solution. The dialysate was collected every thirty minutes for 3 hours and analyzed in HPLC-ED to determine the content of NE and other catecholamines. Interstitial levels of NE were higher in SH than in WKY rats in both tissues. Mean NE values from subcutaneous adipose tissue in 4-5 week-old SHR were 1162 +/- 193 pg/ml compared to 496 + 188 pg/ml in WKY rats (p<0.001, t test). Muscle tissue NE levels in SHR were 1241 +/- 337 pg/ml vs. 521 +/- 138 pg/ml in WKY rats (p<0.001, t test). Plasma NE concentrations (279 +/- 61 pg/ml in SHR vs 246 + 69 pg/ml in WKY P = 0.65, t test) were not significantly different between the two strains at this young age. These findings suggest SNS hyperactivity in young SHR, though still normotensive, possibly dissociated from regional components of regulation (baroreceptor control in striated muscle and metabolic control in subcutaneous adipose tissue).

Adipose Tissue↗

Heart transplantation 1985-1998: 13-years experience at Angelo De Gasperis Cardio-Thoracic Department-Milan.

BACKGROUND: After 13 years of transplant experience in our center, we analyzed the results in the overall population and in particular subgroups of heart transplant recipients. We tried to identify risk factors for both early (3 months) and late (over 3 months) mortality after heart transplantation. METHODS: The data on 461 patients transplanted from November 1985-June 1998 were reviewed. To study risk factors for mortality, the results for 313 patients operated on from June 1985-June 1995 were studied and analyzed with a multivariate logistic regression and Cox's proportional hazard model. Seventy pre-, intra- and postoperative variables were considered including patient demographics, clinical status, hemodynamic parameters, donor characteristics, donor-recipient HLA mismatches, complications, and immunosuppressive protocols. We also compared results for patients transplanted from 1985-1991 (Group 1) and from 1992-1998 (Group II) to assess improvements due to changes in indications and in perioperative treatments. RESULTS: Overall mortality in the entire population was 20.2% (93/461). The 30-day, 3-month and late mortality rates were 8.0%, 10.2%, 11.1%, respectively. Group II mortality rates were 6.5%, 8.5% and 6.8%, respectively, despite a significant increase in Status I patients (20.6% in Group I vs 49.0% in Group II, p = 0.0001). The main causes of death were graft failure (24.7%), cardiac allograft vasculopathy (18.3%), and infection (16.1%). The mean follow-up of the 414 recipients who survived more than 3 months was 54.0 +/- 37.3 months. Actuarial survival was 87.4%, 79.2% and 68.9% at one, 5 and 10 years, respectively. The difference in the 5-year actuarial survival rates between Group I and Group II patients was statistically significant (73.5% vs 83.9%, p = 0.0135). The transpulmonary gradient, right atrial pressure and mid-high doses of donor inotropic support were identified as independent risk factors for early mortality. The number of moderate rejections at biopsy and early posttransplant infections were identified as independent risk factors for late mortality. The results of patients transplanted while on ventricular assist devices, urgent and elective patients and combined heart and kidney transplants were also reported. CONCLUSIONS: The overall results of our 13-year experience are very satisfying in relation to early and late mortality, with a significant favorable trend between patients transplanted in the early era (1985-1991) and those transplanted in the recent era (1992-1998). Pulmonary hypertension and elevated preoperative right filling pressure appear to indicate a significantly increased risk of early death and only marginally influence late survival, which is principally influenced by severe postoperative complications. Good results were achieved in combined heart and kidney transplantation and among patients who deteriorated during the waiting period and were supported with ventricular assist devices. The early and late outcomes for urgent (status I) and elective (status II) heart transplant patients were comparable.

Adolescent↗

Use of Fourier shape descriptors to improve the reproducibility of echographic measurements of arterial intima-media thickness.

BACKGROUND: A major source of error in the longitudinal assessment of the intima-media thickness (IMT) is the difficulty in retrieving the same echographic view of the vessel. OBJECTIVE: To present a method for increasing the reproducibility of IMT measurements by ultrasound in large arteries. METHOD: The Fourier descriptor is a well-known means of describing an object's shape. By means of the discrete Fourier transform (DFT), the shape was represented in a frequency domain; the computational advantages of the DFT then permitted a measure of unlikeness between different shapes (the 'distance' measure; DM) to be defined and used as a criterion for reproducing the contour. When the sonographer compared successive images of a complex vascular segment, like the carotid bifurcation, the identity of the echographic cut was deduced from the identity of the vessel's contour. The best match of the baseline image was the view that minimized the contour DM. RESULTS: Preliminary studies in the carotid artery bifurcations of eight subjects showed that the DM responds to systematic variations in the ultrasound interrogation angle and reveals minimal changes in transducer position. Duplicate scans of 12 subjects were performed by three sonographers with different strategies for acquisition of the same images: a low DM was associated with a low difference in pairs of IMT measurements. Data were classified into two groups (normal or borderline vessels with a pooled mean IMT of 0.62 mm and overtly thickened segments with a pooled mean IMT of 1.31 mm). When minimization of the DM was the criterion for the acquisition of replicate scans, the mean absolute difference of paired data for the mean IMT of the distal common carotid artery was 0.03 +/- 0.02 mm for the first group and 0.06 +/- 0.03 mm for the second group. This is a significant reduction in comparison with non-quantitative alternative criteria for image reproduction. For the maximum IMT of the same segments the mean absolute differences were 0.07 +/- 0.03 and 0.13 +/- 0.06 mm in the first and second groups, respectively. CONCLUSION: This method can be applied to the serial assessment of single atherosclerotic segments. The computational time is negligible. By reducing the scatter in sequential IMT data, longitudinal investigations (e.g. of the results of antihypertensive therapy) with shorter durations and smaller sample groups may be rendered feasible.

Algorithms↗

[The relationship between regional sympathetic activity and the onset of arterial hypertension in spontaneously hypertensive rats].

Several studies on spontaneously hypertensive rats (SHR) have demonstrated increased activity of the sympathetic nervous system (SNS). Using microdialysis, we have observed a greater release of norepinephrine (NE) into the interstitia of striated muscle, than that observed in control Wistar-Kyoto (WKY) rats in the prehypertensive phase. We confirmed these results in the subcutaneous adipose tissue where the sympathetic output controls metabolism. This study was carried out in order to evaluate SNS activity in two district tissue types conducted during both the prehypertensive phase (4-5 weeks of age) and the established hypertensive phase (15-16 weeks of age). Interstitial concentrations of NE were measured by microdialysis in striated muscle and subcutaneous adipose tissue. Two groups of rats were studied. Each group was made up of 8 subjects, SHR and WKY, males of 4-5 weeks of age with a mean body weight of 80 and 75 g respectively. Arterial systolic pressure (tail-cuff) values were 106 mmHg (standard deviation +/-8.2) in SHR and 101 mmHg (standard deviation +/-6.9) in WKY rats (NS). Two microdialysis probes were positioned in the subcutaneous fatty tissue and in the striated muscle of the parascapular region and perfused with Ringers' solution. The dialysate was collected every 30 min for 150 min and analyzed in high-performance liquid chromatography-every day. The content of NE and other catecholamines was determined. The same animals in both groups were reevaluated at 15-16 weeks of age. The mean body weight at this time was 246 g for the SHR and 289 g for the WKY rats. Arterial systolic pressure was 161 mmHg (standard deviation +/-13.3) and 108 mmHg (standard deviation +/-15.6) respectively (p < 0.01, Student's t test). Interstitial levels of NE were higher in SHR than in WKY rats in both tissues examined in the prehypertensive phase and in the established hypertensive phase. Mean NE values from subcutaneous adipose tissue in 4-5 week-old SHR were 1362.1 +/- 181.3 pg/ml compared to 479.0 +/- 162.3 pg/ml in WKY rats (p < 0.001, Student's t test). Muscle tissue NE levels in SHR were 1292.7 +/- 319.1 vs 536.3 +/- 146.7 pg/ml in WKY rats (p < 0.001, Student's t test). Values from the same rats at 15-16 weeks of age were 1405.0 +/- 148.3 pg/ml in SHR compared to 501.6 +/- 131.2 pg/ml in fatty tissue from WKY rats and 1893.7 +/- 214.6 vs 502.0 +/- 118.8 pg/ml in muscle tissue from the respective groups (p < 0.001, Student's t test). Significant differences (p < 0.01, Student's t test) were also observed in mean NE values in striated muscle tissue during the developing phase of hypertension. These findings document SNS hyperactivity in SHR when compared to WKY normotensive controls. This increase in SNS activity was observed in both the prehypertensive phase and in the established hypertensive phase indicating a complete disassociation from regional components of regulation (baroreceptor control and metabolic control), at least in the prehypertensive phase. These results may suggest as alteration in primitive sympathetic central outflow. Higher interstitial NE concentrations in the muscle tissue from SHR during the hypertensive phase compared to levels of young animals that are still normotensive, reveal an interesting pathophysiological aspect for the development of arterial hypertension.

Animals↗