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Biomedical subjects

R Ruggiero

Publications and source records attributed to R Ruggiero.

At least 37 records · Page 2Linked to original sources
PubMed1994

Cortical kidney scan evaluation in the follow-up of children with vesico-ureteric reflux.

We present the results obtained in the follow-up of 66 children with vesico-ureteric reflux (VUR) of different grades (111 refluxing renal units, RU; the VUR being bilateral in 47 children), employing the renal cortical agent 99mTc-aprotinin (TcA). Together with the visual inspection of the scan, we adopted a quantitative approach, expressing the results as the split percent uptake of the injected dose. The detection of morphological anomalies was more frequent in the cases of more severe reflux. Scars were noted in 38 RU, with a higher prevalence in more severe grades, except for grade V where severe impairment was more frequent. With regard to the amount of functioning parenchyma, the probability of a significant loss of nephrons (expressed by a low uptake of TcA), rose with the grades, although the higher grades were not invariably associated with parenchymal failure. The abnormality detection rate is higher by about 2:1 with the TcA scan than with other diagnostic modalities such as i.v. pyelography or echography. No differences were found between RU with or without scars as regards evolution over time; only when the TcA uptake at presentation was lower than 10% was the normal development of the RU likely to be hindered. From these data it can be concluded that early diagnosis is the key factor in the management of these children with VUR; the morpho-functional assessment with TcA uptake is probably the most effective technique for the detection of parenchymal abnormalities. In addition, the test has a high prognostic value, an uptake lower than 10% indicating an unfavourable prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aprotinin↗
PubMed1994

Detection of canine allograft lung rejection by pulmonary lymphoscintigraphy.

We previously demonstrated that lymphoscintigraphy could be used to study pulmonary lymphatic flow. Radiocolloids, high-molecular-weight proteins tagged with radioactive markers, are injected percutaneously in the periphery of the lung. These molecules enter the lymph, are transported via lymphatic channels, and concentrate in the tributary hilar and mediastinal lymph nodes, where they can be visualized by nuclear scan. The goal of this study was to determine whether pulmonary lymphoscintigraphy could be used to detect allograft rejection after lung transplantation. Thirteen mongrel dogs underwent left lung allotransplantation. Cyclosporine 15 mg/kg per day and azathioprine 1 mg/kg per day were given orally for postoperative immunosuppression. Lymphoscintigraphic studies were obtained 1 week after the operation and then at weekly intervals. In five dogs (group A), immunosuppression was continued until the animal died or was put to death 6 weeks later. Lymphoscintigraphy demonstrated reestablishment of lymphatic drainage between the lung graft and the mediastinum in all the animals 2 to 4 weeks after transplantation. In eight dogs (group B), immunosuppression was discontinued after reestablishment of graft lymphatic drainage was documented by two consecutive lymphoscintigraphic studies. The dogs continued to be studied with weekly scans. In group B, lymphatic drainage from the lung graft to the mediastinum disappeared 1 to 4 weeks after immunosuppression was stopped. Rejection was diagnosed clinically and confirmed histologically with open lung biopsies and/or autopsies in all animals. This study shows that canine allograft lung rejection is associated with disappearance of lymphatic drainage from lung graft to mediastinum, which can be documented by pulmonary lymphoscintigraphy, a minimally invasive technique that can be easily repeated. Pulmonary lymphoscintigraphy may be useful for early detection of lung allograft rejection.

Acute Disease↗
PubMed1993

Functional evaluation of intrathoracic versus extrathoracic skeletal muscle ventricles.

Skeletal muscle ventricles (SMVs) were constructed from the latissimus dorsi muscle in 10 dogs. In Group I (n = 5), SMVs were left in an extrathoracic position on the chest wall. In Group II (n = 5), SMVs were placed within the chest cavity. After a 3- to 4-week vascular delay period, SMVs were electrically preconditioned with 2 Hz continuous stimulation for 6 weeks. At a second procedure, SMVs were connected to a mock circulation system, and function was evaluated under differing conditions of preload and afterload. SMVs in Group II were significantly more compliant, as demonstrated by the end diastolic pressure volume relationship, than those in Group I (P < 0.01). SMVs in Group II were also capable of generating greater stroke work than those in Group I (P < 0.05). SMVs in Group II were also capable of greater stroke work than those in Group I at physiologic preloads (P < 0.05). These findings suggest that SMVs placed in an intrathoracic position exhibit better diastolic and systolic function.

Animals↗
PubMed1993

Double cardiomyoplasty: acute versus chronic results.

We previously found that double cardiomyoplasty using both acutely raised, unconditioned latissimus dorsi muscles increased cardiac output by 9.6% (1,547 +/- 154 versus 1,695 +/- 166 mL/min), stroke volume by 18.2% (12.1 +/- 0.6 versus 14.3 +/- 0.7 mL), peak left ventricular pressure by 18.4% (98 +/- 3 versus 116 +/- 5 mm Hg), and peak right ventricular pressure by 62.5% (24 +/- 2 versus 39 +/- 4 mm Hg) (p < 0.05 for all differences). In this study 10 dogs underwent double cardiomyoplasty: 3 died perioperatively, and 7 underwent 8 weeks of muscle conditioning. After the conditioning period, the muscle flaps did not contract in 2 of the 7 dogs. Hemodynamics were measured in the remaining 5 dogs. Using fatigue-resistant muscle, cardiac output decreased by 3.7% (1,279 +/- 262 versus 1,233 +/- 274 mL/min), stroke volume decreased by 9.0% (9.5 +/- 1.2 versus 8.8 +/- 1.2 mL), and peak left ventricular pressure increased by 10.6% (82.1 +/- 6.5 versus 90.8 +/- 3.2 mm Hg), but not significantly. Peak right ventricular pressure increased significantly by 31.3% (24.3 +/- 2.1 versus 31.9 +/- 3.6 mm Hg; p < 0.05). Hemodynamic effects of individual left or right muscle contractions versus bilateral muscle stimulation were not significantly different except for a greater percentage increase in peak right ventricular pressure (right, 24.9 +/- 2.1 mm Hg unstimulated versus 28.0 +/- 2.1 stimulated; left, 26.3 +/- 0.9 mm Hg unstimulated versus 30.7 +/- 2.4 mm Hg stimulated; bilateral, 24.3 +/- 2.1 mm Hg unstimulated versus 31.9 +/- 3.4 mm Hg stimulated; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Skeletal muscle ventricles: left ventricular apex to aorta configuration.

Skeletal muscle ventricles (SMVs) were constructed from the latissimus dorsi muscle in 6 dogs. After 3 weeks of vascular delay followed by 6 weeks of 2-Hz continuous electrical conditioning, a valved conduit was placed between the left ventricular apex and the SMV and a second valved conduit, between the SMV and the aorta. The SMV was stimulated to contract during diastole at a 1:2 ratio with the heart. The SMV pumped 47% of the systemic blood flow initially (0.73 +/- 0.23 versus 1.54 +/- 0.42 L/min) and 40% after 3 hours. Skeletal muscle ventricle stimulation resulted in a 58% increase in mean diastolic pressure initially (52 +/- 9 to 82 +/- 11 mm Hg; p < 0.05) and a 73% increase (45 +/- 7 to 78 +/- 8 mm Hg) after 3 hours of continuous pumping. This was associated with a 68% increase in the endocardial viability ratio initially and a 63% increase at 3 hours. The systolic tension-time index decreased by 26% initially and 25% at 3 hours. This study indicates that the SMV configuration of left ventricular apex to aorta may be particularly suitable for left ventricular assist.

Animals↗
PubMed1993

Reestablishment of lymphatic drainage after canine lung transplantation.

The technique of pulmonary lymphoscintigraphy was used to evaluate pulmonary lymphatic flow and to assess reestablishment of lymphatic drainage after lung transplantation. A first group of six control dogs underwent percutaneous transthoracic injection of a radiocolloid into the periphery of the left upper and lower lobes. Radiocolloids are large molecules tagged with radioisotopes that are absorbed only through lymph and are concentrated in tributary lymph nodes. Twenty-four hours after injection the dogs underwent scintigraphic studies of the chest and upper part of the abdomen. Mediastinal lymph nodes were visualized in all animals. A second group of four dogs underwent partial reimplantation of the native left lung, with interruption of all lymphatic connections between the lung and mediastinum. Lymphoscintigraphic studies of the left lung were obtained on the third postoperative day and then weekly for 4 weeks. Three of the four dogs in this group did not have visible mediastinal nodes 3 days after the operation. Nodes were visualized in all animals at 1 week and at all following studies. A third group of five dogs were subjected to left lung allotransplantation by means of standard surgical techniques, as well as immunosuppression. The animals were studied with radiocolloid injections and lung lymphoscintigraphy at weekly intervals for 6 weeks. Mediastinal nodes were visualized for the first time 2 to 4 weeks after the operation and at every subsequent study. We conclude that lung lymphoscintigraphy is a reliable technique for the study of pulmonary lymphatic flow. This experiment demonstrates that lymphatic drainage after lung transplantation is reestablished as early as the second postoperative week.

Animals↗
PubMed1992

Skeletal muscle ventricles with improved thromboresistance: 28 weeks in circulation.

Skeletal muscle ventricles (SMVs) were constructed from the left latissimus dorsi in 22 mongrel dogs. The configuration of these SMVs was different from those previously reported. The animals were divided into two groups: group A (n = 11) SMVs rested for 10 weeks after construction; group B (n = 11) SMVs rested for 18 weeks. At the end of the delay period, SMVs were tested in vivo with a mock circulation device. The SMVs in group B developed stroke work greater than those in group A. After acute testing, SMVs (n = 12) were connected to the descending thoracic aorta and stimulated to contract during diastole. Aortic diastolic counterpulsation was achieved in all dogs, with 9 animals surviving from 1 to beyond 28 weeks. In all of the dogs surviving 1 week or more, the SMVs remained free of thrombus. Aspirin was used as the only antithrombotic agent. Skeletal muscle ventricles in this study were able to develop stroke work similar to that previously reported, intermediate between that of the right and left ventricular stroke work, with a significantly decreased incidence of thromboembolism.

Animals↗
PubMed1992

Skeletal muscle ventricles as left atrial-aortic pumps: short-term studies.

In 5 dogs, skeletal muscle ventricles (SMVs) were constructed from the latissimus dorsi muscle and placed in the left hemithorax. After a 3-week vascular delay period, SMVs were electrically preconditioned with 2-Hz stimulation for 6 weeks. At a second operation, SMVs were connected between the left atrium and thoracic aorta by afferent and efferent aortic root homografts, and stimulated to contract in a 1:2 diastolic mode. At a mean left atrial pressure of 12.4 +/- 1.3 mm Hg and a burst stimulation frequency of 33 Hz, SMV stroke volume was initially 43% of that of the native left ventricle, achieving a flow equivalent to 21% of cardiac output (194 +/- 38 versus 902 +/- 85 mL/min). At 50-Hz stimulation, this figure rose to 27% (246 +/- 41 mL/min; p less than 0.05). Skeletal muscle ventricle power output (the product of stroke work and contraction rate) at 33 Hz was 0.016 +/- 0.003 W, increasing to 0.024 +/- 0.004 W at 50 Hz (p less than 0.05), corresponding to 14% and 22%, respectively, of left ventricular power output (0.11 +/- 0.012 W). After 4 hours of continuous pumping, four of the SMVs were still generating flows of more than 70% of starting values and more than 60% of initial power output. This study demonstrates that SMVs can function in the systemic circulation at physiologic left atrial preloads.

Animals↗
PubMed1992

Skeletal muscle ventricles in the pulmonary circulation: up to 16 weeks' experience.

Skeletal muscle ventricles (SMVs) were constructed from the right latissimus dorsi muscle of 8 mongrel dogs. After a 3-week vascular delay period, each SMV was electrically preconditioned with 2-Hz continuous stimulation of the thoracodorsal nerve for 6 weeks. A porcine-valved conduit was then anastomosed between the right ventricle and the SMV, with a second valved conduit connecting the SMV to the main pulmonary artery. The pulmonary artery was then ligated proximal to the conduit. The SMVs were stimulated to contract in 1:2 diastolic mode with a 33-Hz burst frequency. Effective right ventricular assist was achieved in all dogs. Cardiac output increased by 22.6% (1,799 +/- 97 versus 1,467 +/- 84 mL/min; p less than 0.001), systemic systolic arterial pressure by 9.3% (90.1 +/- 3.5 versus 82.4 +/- 3.9 mm Hg; p less than 0.005), and peak pulmonary artery pressure by 31.8% (27.8 +/- 2.0 versus 21.1 +/- 1.7 mm Hg; p less than 0.001) at the initiation of this study. In 6 dogs, effective right heart assist was sustained for periods of between 1 week and 12 weeks. Two dogs survived for longer than 3 months, though with evidence of deteriorating SMV function. These results demonstrate the feasibility of providing sustained right ventricular assist using this modified "Rastelli-SMV" configuration, which obviates the limitations imposed by low right atrial preload.

Adaptation, Physiological↗
PubMed1991

Skeletal muscle ventricles: update after 18 months in circulation.

Skeletal muscle ventricles (SMVs) have been constructed from canine latissimus dorsi muscle and connected to the aorta as aortic diastolic counterpulsators. Presently one dog remains alive and well with an SMV that has been functioning continuously in circulation for 18 months, without evidence of thromboembolic complications. SMVs are able to perform cardiac-type work with an output equal to that of the left ventricle at physiologic preloads, when tested with a mock circulation device in our laboratory. SMVs have been used for right-sided cardiac assist. In acute experiments these ventricles have functioned effectively, bypassing the right side of the heart for up to 8 h. Most recently we have tested SMVs using them chronically to pump blood in the right-sided circulation, and at the time of writing they have been shown to function effectively in this configuration for up to 18 days. SMVs may be used in the future as a method of treating patients with left- or right-sided heart failure.

Animals↗
PubMed1991

Autologous skeletal muscle, an alternative for cardiac assistance.

Original attempts to use skeletal muscle for cardiac assistance were soon abandoned when the problem of muscle fatigue could not be solved. In the last 2 decades, better understanding of muscle physiology and the development of successful protocols of electrical muscle conditioning have given new impetus to researchers around the world to proceed in the effort to identify useful applications of skeletal muscle to support the heart. More than 100 patients around the world have undergone cardiomyoplasty, mostly for cardiac failure. While subjective improvement in symptoms was noticed in the majority of the patients, only recently favorable hemodynamic changes have been documented. The other alternative that has been pursued in the laboratory is the construction of skeletal muscle ventricles that, after conditioning and vascular delay, have been shown to provide significant cardiac support when used for diastolic counterpulsation or for right heart bypass in animal models.

Cardiac Surgical Procedures↗
PubMed1991

Intrathoracic skeletal muscle ventricles: a feasibility study.

For skeletal muscle ventricles (SMVs) to be applied clinically, it is likely that they will have to be placed within the chest. Ease of subsequent connection to the circulation, and avoidance of significant lung compression, are factors that could influence SMV size and shape in a way that may prejudice their ability to pump effectively at physiological preloads. In five dogs, specially designed SMVs were constructed from the latissimus dorsi muscle, and placed in the apex of the left hemithorax. After a 3-week delay, the muscle was preconditioned electrically by 2-Hz continuous stimulation for 6 weeks. At a later thoracotomy, this positioning of SMVs permitted easy surgical access to the heart and great vessels. SMVs were then connected to a mock circulation device for functional evaluation. As right-sided pumps, at a preload of 10 mmHg, SMVs generated a stroke volume (SV) and stroke work (SW) exceeding that of the native right ventricle (SV = 8.9 +/- 0.8 vs 7.9 +/- 0.6 mL; SW = 0.44 +/- 0.03 vs 0.20 ergs x 10(6)). As left-sided pumps, also at a preload of 10 mmHg, SMV SV, and SW was roughly half that of the left ventricle (SV = 3.7 +/- 0.2 vs 7.9 +/- 0.6 mL; SW = 0.29 +/- 0.03 vs 0.57 +/- 0.05 ergs x 10(6)). SMVs may conveniently be positioned inside the chest, where they have the potential to function as left or right heart assist devices.

Animals↗
PubMed1991

Canine latissimus dorsi cardio-double myoplasty: acute feasibility study.

Cardio-double myoplasty was performed in eight mongrel dogs. Both latissimus dorsi muscles were dissected from the chest wall and wrapped around the heart. They were then stimulated using an R wave synchronous stimulator. Hemodynamic measurements were obtained, first with the stimulator off and then with stimulator activated. After measuring hemodynamic effects in a normal heart, acute heart failure was induced by the infusion of propranolol (5 mg/kg). Hemodynamic data were then obtained in the same fashion. In a normal heart state, cardio-double myoplasty increased the cardiac output 9.9% +/- 2.24 (p less than 0.005), the left ventricular pressure 18.7% +/- 3.53 (p less than 0.001), the pulmonary artery pressure 72.2% +/- 25.4 (p less than 0.01), and the stroke volume 13.4% +/- 5.73 (p less than 0.05). In a failing heart, the cardiac output increased 21.6% +/- 3.34 (p less than 0.005), the left ventricular pressure increased 20.8% +/- 3.34 (p less than 0.005), the pulmonary artery pressure increased 87.2% +/- 39.9 (p less than 0.05), and the stroke volume increased 46.9% +/- 22.9 (p less than 0.05). The left ventricular end-diastolic pressure decreased slightly and the central venous pressure did not change in either the normal state or during cardiac failure. Cardio-double myoplasty resulted in a significant circulatory augmentation particularly in the setting of cardiac failure.

Animals↗
PubMed1991

Skeletal muscle ventricles: a promising treatment option for heart failure.

Our most recent work on cardiac assist with canine latissimus dorsi muscle in a skeletal muscle ventricle (SMV) configuration is reported here. One animal's SMV has been pumping blood effectively in the circulation for more than 16 months. To date there is no evidence of thromboembolism, and the dog has suffered no untoward effects. It has recently been shown, in a mock circulation study, that canine SMVs are capable of developing stroke work, at physiological preloads, much greater than that of the right ventricle and equivalent to that of the left ventricle. The improved ability of conditioned SMVs to perform work, independent of the circulation, during severe hypotension is also demonstrated. In the face of a 75% drop in left ventricular stroke work, the SMV stroke work dropped by only 50%. The continuing work on this subject suggests that a skeletal muscle ventricle may have the potential of becoming a viable alternative in the treatment of heart failure.

Animals↗
PubMed1991

A new configuration for right ventricular assist with skeletal muscle ventricle. Short-term studies.

BACKGROUND: Previous attempts to provide right heart assistance with skeletal muscle ventricles (SMVs) have been frustrated by the low preload supplied by the systemic venous blood pressure. In the present study, right ventricular pressure was exploited to provide more optimal preload, the SMV being connected by valved conduits between right ventricular free wall and the main pulmonary artery. METHODS AND RESULTS: SMVs were constructed from the right latissimus dorsi muscle in seven mongrel dogs. Following a delay period of 4 weeks, SMVs were preconditioned with 2-Hz continuous stimulation for 5-6 weeks. The SMV was then connected to the right ventricle using a porcine valved Dacron conduit. A similar valved conduit connected the SMV to the main pulmonary artery that had been ligated proximally. SMVs were stimulated with 33-Hz burst frequency to contract synchronously with ventricular diastole in a 1:2 mode. The stimulator was intermittently turned off to permit comparison of assisted and nonassisted circulation. Cardiac output increased by 27% at 1 hour (1,437 +/- 54 versus 1,140 +/- 64 ml/min, p less than 0.005) and by 30% at 4 hours (1,403 +/- 161 versus 1,074 +/- 99 ml/min, p less than 0.005), systemic arterial systolic pressure increased at 1 hour by 12% (87.1 +/- 4.9 versus 78.0 +/- 4.9 mm Hg, p less than 0.05) and by 13% at 4 hours (81.4 +/- 2.8 versus 72.3 +/- 3.4 mm Hg, p less than 0.005), and peak pulmonary arterial pressure increased at 1 hour by 35% (28.0 +/- 2.1 versus 20.9 +/- 1.8 mm Hg, p less than 0.01) and by 37% at 4 hours (31.5 +/- 2.6 versus 23.0 +/- 0.4 mm Hg, p less than 0.05). Peak SMV pressure was 52.8 +/- 2.0 mm Hg at 1 hour and 49.9 +/- 3.3 mm Hg at 4 hours (p = NS). CONCLUSIONS: The improved preload supplied by this configuration of right ventricular assist enabled an SMV to provide stable and effective circulatory support throughout the 4-hour duration of the experiment.

Animals↗
PubMed1990

[Comparative analysis in gastric cancer of total gastrectomy extended with lymphadenectomy and the other surgical technics. 10 years' experience].

Of 220 patients operated for gastric cancer, 74 with subtotal gastrectomy and 145 with total gastrectomy (60 with lymphadenectomy), the results and indications for total gastrectomy extended with lymphadenectomy are analysed. The importance of lymph node emptying in relation to the possibility of breakdown of the lymphnode chains with R2 metastasis is particularly stressed. Analysis of perioperative mortality and long-term survival indicates results that are close to the data reported by Japanese schools.

Adult↗
PubMed1990

[Anesthesia in the diagnostic stages of cerebral arteriovenous malformations in children under 3 years of age].

From 1974 through 1989, 36 patients with arteriovenous malformations were treated in the neuroradiological unit of the Santobono Children's Hospital, in Naples, 7 of these patients were younger than 3 years of age. During such a time-span, dramatic improvements in diagnostic work-up were jelded by introduction of CT-scan and MRI; better angiographic techniques, progress in anaesthesia drugs, equipment and procedures and more rational surgical modalities. Anaesthesia must be tailored in each patient with special consideration of the clinical and neurological conditions of the patients as well of the neuroradiological procedure, specifically, with minimal side effects on cardiovascular and respiratory functions as well on intracranial pressure. The present paper discuss of equipment for cardiovascular assistance and drugs to be employed in the various steps of the diagnostic work-up of such patients.

Anesthesia, General↗