Roberto Lorusso

The Italian study of the Mitroflow postoperative results (ISTHMUS): a 20-year, multicenter evaluation of Mitroflow pericardial bioprosthesis

OBJECTIVE A multicentre experience with the Mitroflow pericardial bioprosthesis has been evaluated longitudinally over a 20-year period. METHODS From 1988 through 2008, 1591 patients (mean age, 75.3±6.8 years, and 60.1% female) from 12 centres had a Mitroflow in the aortic position. Concomitant coronary artery bypass was performed in 41.9% (n=666) of patients, urgency/emergency surgery in 9.5% (n=152) and replacement of degenerated prosthesis in 2.3% (n=36). Follow-up (7.447 patient-years) was 99.2% complete. Median follow-up was 61.9 months (interquartile range (IQR) 30.8-90.9 months). The study was carried out following American Association for Thoracic Surgery/Society for Thoracic Surgeons/European Association for Cardio-Thoracic Surgery (AATS/STS/EACTS) Guidelines for reporting valve morbidity and mortality. RESULTS The early (30-day) mortality was 6.5% (n=104). Actuarial survival rates at 10, 15 and 18 years were 53%, 34% and 27%, respectively (2.2 patient/year). Re-operation was required in 96 patients (5.9%), of whom 59 patients (3.7%) for structural valve degeneration. Actuarial freedom from prosthetic valve degeneration at 18 years was 65.5% (78% in patients>70 years) with a linearised rate of 1.4 patient/year (0.8 patient/year in patients>70 years). At 18 years, freedom from embolism was 82% (0.9 patient/year), freedom from valve endocarditis was 89% (0.6 patient/year) and freedom from bleeding episodes was 95% (0.2 patient/year), respectively. CONCLUSIONS This independent multicentre study indicates that the Mitroflow pericardial bioprosthesis provides favourable long-term postoperative results with a low rate of valve-related events and need of re-intervention, particularly in patients older than 70 years.

Echocardiographic Evaluation of Aortic Atheromas in Patients With Aortic Stenosis

The association of aortic atheromas in patients with isolated aortic stenosis has recently been acknowledged, probably because the pathogenic mechanisms are similar. Therefore, this study evaluated the extent and severity of thoracic aortic atheromas in patients with different grades of aortic stenosis using transesophageal echocardiography.

The Early Phase of Clinical Application: Lessons Learned

The experience of mitral valve repair (MVR) in the presence of anterior or bileaflet involvement has been not as satisfactory as the results of valve reconstruction for isolated posterior leaflet dysfunction [1–4]. Indeed, whereas quadrangular resection or other reparative techniques have been widely applied with remarkable long-lasting effects [5], mitral valve insufficiency (MVI) caused by mechanisms other than isolated posterior leaflet prolapse has been associated with more complex and time-consuming repair methods and has been characterized by higher rates of recurrent MVI [1–4]. The “French correction” proposed by Carpentier certainly provided major breakthroughs for reconstructing the mitral valve in the presence of variable patterns of MVI [6], but postoperative results were indisputably less favorable for specific MVI settings like anterior, bileaflet, or commissural lesions [1–4]. Under these circumstances, the traditional repair techniques proposed were more complex and often not easily reproducible. More expeditious and reliable techniques were advocated by the surgical community to overcome the above mentioned drawbacks in the treatment of MVI. The edge-to-edge (EE) technique was therefore designed to provide a simple, quick, and reproducible procedure meant to restore durable mitral leaflet coaptation in several MVI patterns, but, particularly, to counteract anterior, bileaflet, or commissural-based prolapse and MV regurgitation [7].

Engineering for IABP and ECMO

The use of mechanical devices to compensate the acutely impaired contractile efficiency and power of the heart due to muscular, coronary or valvular diseases has been addressed for almost a century in the history of cardiovascular medicine. Indeed, it is well known that at the beginning of the 20th century, Alexis Carrel and Charles Lindbergh worked together to develop an alternative to the heart pump meant to support the failing circulation. Many other researchers and investigators from 1930 till 1960 investigated several forms and types of mechanical blood circulation and started their application in the clinical setting in the USA, Italy, France, Sweden, Russia, and elsewhere, and extracorporeal circulation (ECC) began to represent a major breakthrough in cardiovascular medicine allowing open heart interventions. The adverse events linked to prolonged ECC and the need for mechanical cardiocirculatory support outside the operating room prompted technicians and clinicians to explore alternative or modified systems to provide partial or full cardiac assistance that could function for several hours, days or weeks. This chapter will describe the development of two systems designed for that objective: a mechanically driven device to partially support the heart through an indirect action, named the intra-aortic balloon pump (IABP), and another system derived from conventional ECC to temporarily help the impaired heart and lung function, named extracorporeal membrane oxygenation (ECMO).