HeartMate III: pump design for a centrifugal LVAD with a magnetically levitated rotor.

A long-term, compact left ventricular assist device (LVAD), the HeartMate III, has been designed and fabricated, featuring a centrifugal pump with a magnetically levitated rotor. The pump has been optimized by in vitro testing to achieve a design point of 7 L/min against 135 mm Hg at high hydrodynamic efficiency (30%) and to be capable of up to 10 L/min under such a load. Furthermore, the pump has demonstrated no mechanical failures, low hemolysis (4-10 mg/dl plasma free Hb), and low thrombogenicity during six (40, 27, 59, 42, 27, and 49-day) in vivo bovine studies.

The Heartmate III: design and in vivo studies of a maglev centrifugal left ventricular assist device.

A compact implantable centrifugal left ventricular assist device (LVAD) (HeartMate III) featuring a magnetically levitated impeller is under development. The goal of our ongoing work is to demonstrate feasibility, low hemolysis, and low thrombogenicity of the titanium pump in chronic bovine in vivo studies. The LVAD is based on so-called bearingless motor technology and combines pump rotor, drive, and magnetic bearing functions in a single unit. The impeller is rotated (theta z) and levitated with both active (X, Y) and passive (Z, theta x, theta y) suspension. Six prototype systems have been built featuring an implantable titanium pump (69 mm diameter, 30 mm height) with textured blood contacting surfaces and extracorporeal electronics. The pumps were implanted in 9 calves (< or = 100 kg at implant) that were anticoagulated with Coumadin (2.5 < or = INR < or = 4.0) throughout the studies. Six studies were electively terminated (at 27-61 days), 1 study was terminated after the development of severe pneumonia and lung atelectasis (at 27 days) another study was terminated after cardiac arrest (at 2 days) while a final study is ongoing (at approximately 100 days). Mean pump flows ranged from 2 to 7 L/min, except for brief periods of exercise at 6 to 9 L/min. Plasma free hemoglobin ranged from 4 to 10 mg/dl. All measured biochemical indicators of end organ function remained within normal range. The pumps have met performance requirements in all 9 implants with acceptable hemolysis and no mechanical failures.

[Primary suppurated splenic cysts. A case report]. / Cisti splenica primaria suppurata. Presentazione di un caso.

The authors describe a case of an epidermoidal cyst of the spleen, which they were able to observe in an emergency case, due to suppuration of the cyst. Primary cysts of the spleen represent a rare dysontegenetic pathological condition which is, for this reason, often underestimated. The general clinical summary is related here, with particular reference to supporative complications, which cause problema of differential diagnosis with patients suffering from abscess of the spleen. The diagnosis can be made as a result of standard X-ray procedures and computed tomography and above all, following a simple scan. The treatment recommended in this case is an open splenectomy, in order to check the allarming clinical symptoms of the patient, which can deteriorate. The use of laparoscopical techniques or trans-cutaneous draining is reserved for salected cases.

[Synergism between cyclosporin and gangliosides in anti-rejection therapy. Experimental in vivo model]. / Sinergismo tra ciclosporina e gangliosidi nella terapia antirigetto. Modello sperimentale in vivo.

In vivo gangliosides (GS) bring about inhibitory effects on the immune response which is attributable to a weakening of the interaction between interleukin-2 (IL-2) and its receptor. In a previous paper we showed that the GS are capable of bringing about in vitro the immunosuppressive power of cyclosporin A CyA2 in this paper we have tried to associate gangliosides (GS) and low dose of CyA in the grafting of rat allogen cutis in order to have in this way in vivo a confirmation of the results previously obtained in vitro. Cutaneous strips taken from Lewis rats were grafted into Sprague Dawley rats and treated for 21 days with intraperitoneal administration of GS, of Cya, and a mixture of the two. The rats were not treated and the rats treated with GS and with CyA separately rejected the graft of the cutis. On the other hand, the use of an association of Gs and CyA brought about a successful graft in 8 rats out of 10. Splenic cells extracted 21 days after the graft from rats treated with GS and with CyA separately were stimulated in vitro with Packweed mitogen (PWM); on the contrary the cells extracted from rats treated with a combination of the two drugs did not react to the stimulation with PWM. Our results show that the GS brings about in vivo the immunosuppressive effects of low doses of CyA.

[The current role of microsurgery in the therapy of idiopathic varicocele]. / Ruolo attuale della microchirurgia nella terapia del varicocele idiopatico.

The authors report a case of recidivant varicocele. After having considered the epidemiological and clinical features of varicocele, traditional and microsurgical technics are analyzed and discussed.