3D planning of ear prosthesis and navigated flapless surgery for craniofacial implants: A pilot study.

New 3D digital technologies can be applied to implant-supported ear prostheses to restore anatomical structures damaged by cancer, dysplasia, or trauma. However, several factors influence the accuracy of implant positioning using a cranial template. This pilot study describes an innovative navigated flapless surgery for craniofacial implants, prosthetically guided by 3D planning of the ear prosthesis. Laser surface scanning of the face allowed for mapping of the healthy ear onto the defect site, and projection of the volume and position of the final prosthesis. The projected ear volume was superimposed on the skull bone image obtained by cone-beam computed tomography (CBCT), performed with the navigation system marker plate positioned in the patient's mouth. The craniofacial implants were fitted optimally to the ear prosthesis. After system calibration, real-time navigated implant placement based on the virtual planning was performed with minimally invasive flapless surgery under local anesthesia. After 3 months of healing, digital impressions of the implants were made, and the digital manufacturing workflow was completed to manufacture the ear prosthesis anchored to the craniofacial implants. The proposed digital method facilitated implant positioning during flapless surgery, improving the ear prosthesis manufacturing process and reducing operation time, patient morbidity, and related costs. This protocol avoids the need for a reference tool fixed in the cranial bone, as is usually required for maxillofacial surgery, and confirmed that surgical navigation is useful for guiding the insertion of craniofacial implants during flapless surgery.

[State of the art and scientific evidence on the role of unidirectional airflow ventilation systems in reducing surgical site infections]. / Stato dell'arte ed evidenze scientifiche sul ruolo dei sistemi di ventilazione a flusso unidirezionale nella riduzione delle infezioni del sito chirurgico.

The use of unidirectional airflow ventilation systems in operating rooms is frequently recommended for the prevention of Surgical Site Infections (SSI). However, scientific evidence is lacking to clearly support this technology which entails high investment costs and operating expenses, as compared with traditional ventilation systems. This sparse evidence is mainly related to the small number of interventions analyzed in each study and the difficulty to distinguish the effects of ventilation and other important confounding factors, such as antibiotic prophylaxis, special operating staff clothing and adoption of educational and training programs against SSI for the surgical personnel. The different behavior of the industrialized countries towards this issue, as it comes out analyzing the existing Rules and Guidelines concerning operating rooms ventilation, reflects a precautionary approach towards a technology which, until recently, has clearly demonstrated neither benefits nor limitations. In 2008, a relevant scientific study was published, reporting results from 63 departments of 55 German hospitals for a total of 99.230 surgical interventions, in which a standardized SSI surveillance was performed. Unexpectedly, the study concluded that unidirectional airflow ventilation showed no benefit and was even associated with a significantly higher risk for severe SSI, as compared with turbulent clean air. The present review collects updates from the scientific literature and national and international Rules and Guidelines concerning the use of unidirectional airflow ventilation systems in operating rooms, analyzing all aspects involved in this issue, from the debated efficacy of these systems in reducing the incidence of SSI to the "side effects" associated to their use, as the relevant costs and the reduction of the environmental comfort for the operators.

A new hermetic antenna for wireless transmission systems of implantable medical devices.

In implantable medical devices (IMDs), the need of telemetry systems able to provide wireless bidirectional communication to interrogate and remotely program the device, as well as to monitor the physiological status of the patient, is growing. The object of the present study was to evaluate a new hermetic antenna for wireless short-range transmission system for IMDs which would assure reliable long-term functioning due to the high level of hermeticity of antenna's housing that limits the influence of body tissue environment on transmitted signals. Experimental tests were conducted on three different prototypes to evaluate the most efficient antenna configuration for transmission both in the air and through a mixture simulating the human thorax. Further tests were performed to assess the influence of electro-catheters connected to IMDs on transmitted signals. Results showed that the hermetic antenna guarantees a good wireless transmission both in the air and through the human thorax simulator. The results also show that the presence of an electro-catheter can influence the effective radiated power (ERP) transmitted depending on its position in relation to the telemetric circuitry. Both a controlled increase of the ERP without exceeding the limits imposed by rules and the optimization of the tuning between the antenna and the transmitter can assure a reliable short-range transmission (several meters) using the new hermetic antenna proposed.

[Cost evaluation of a ventilation system for operating theatre: an ultraclean design versus a conventional one]. / Valutazione dei costi di un impianto di ventilazione per un blocco operatorio: confronto tra sistema "ultraclean" e convenzionale.

The postoperative infection has been recognized as a critical problem in healthcare, increasing patients'complications and hospitalization costs. At the moment the scientific evidence clearly linking ventilation parameters, such as air changes per hour, bacterial counts and infection, is lacking, with the exception of prosthetic joint surgery. This study aims to evaluate the building and operating costs of an ultraclean system versus a conventional one (which satisfies the minimum performance requested by rules), also considering the debating efficacy of ultraclean ventilation on prevention of postoperative infection. The results of our study show an increase of 24% in the building costs and of 34% in the annual operating costs for the ultraclean system versus the conventional one. The estimated 24% increase of the building costs for the ultraclean ventilation system represents only a 5% increase if compared to the total cost of a not equipped operating theatre. Therefore, the increase on costs linked to the use of high performance ventilation facilities seems to be so small that overcoming current rules towards ultraclean systems could be acceptable.

Considerations on isolation rooms and alternative pressure ventilation systems.

The health-care facility environment is involved in disease transmission in essentially two different situations: 1. in cases where patients are immunocompromised and require protection from infections; 2. in cases of inadvertent exposure to environmental or airborne pathogens that can aggravate patients' existent disease and cause illness among health-care personnel. Environmental infection-control strategies and engineering controls can effectively prevent transmission of these infections. In particular the ventilation system is fundamental to the control of the concentration of airborne contaminants within a hospital isolation room because it establishes and maintains appropriate pressure differentials within special care areas of the building. Thus the incidence of health-care-associated infections can be minimized by adherence to ventilation standards suggested in the guidelines for specialized care environments such as Airborne Infection Isolation rooms (AII, as in situation 2 above), and Protective Environments (PE) rooms (as in situation 1 above). This report is a comparative review of the principal guidelines and strategies existing in the international scientific literature for the prevention of environment-associated infections in healthcare facilities using pressure differentials (positive pressure for PE rooms, negative pressure for AII rooms). The purpose of the review is also to investigate the state-of-the-art use of the "alternative pressure rooms", i.e., areas furnished with a ventilation system capable of switching pressure from positive to negative according to patients' needs. The results of the present analysis indicate an unenthusiastic reaction to these "alternative pressure rooms", although there is no scientific evidence against their use.