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Background Laparoscopic surgery (LS) is contemplated during long duration space flight, but it typically necessitates intraabdominal hypertension (IAH) from insufflation to create a surgical domain. Because there are spontaneous changes in abdominal wall behavior in weightlessness (0g) that have been previously suggested to increase LS visualization, we studied the comparative laparoscopic visualization between gasless (noGAS), abdominal wall retraction (AWR), and standard 15 mmHg gas insufflation (GAS) during weightlessness. Study Design In-flight LS was performed on four anesthetized pigs during weightlessness obtained through parabolic flight in a research aircraft. GAS was studied during 27 parabolas and compared with 20 parabolas using AWR-LS and 12 with noGAS. Pelvic visualization was scored in real time during flight by 2 or 3 surgeons per parabola and postflight through review of compiled digital video disk (DVD) images by 29 independent reviewers. Physical measurements of the sagittal (anterior-posterior) and transverse dimensions of anesthetized pigs were recorded during 39 parabolas. Results Despite consistent increases in the sagittal abdominal dimension in weightlessness (GAS and noGAS), on-board scored visualization in 0g was unchanged for noGAS (p=0.78) and decreased during AWR (p=0.09), compared with 1g. Although AWR was considered feasible in 1g, spontaneous visceral movements reduced the surgical domain in 0g. Neither AWR nor noGAS was believed safe. But visualization during GAS in 0g was increased over that in 1g (p Conclusions Both noGAS and AWR are impractical in weightlessness. Gas insufflation will be required. With insufflation, visualization and perceived ability to perform LS was improved by weightlessness.

Laparoscopic surgery (LS) is envisioned as an option for spaceflight, but requires intra-abdominal hypertension (IAH) to create the surgical domain. Prolonged weightlessness induces physiologic deconditioning that questions the ability of ill or injured astronauts to tolerate IAH. On earth, IAH results in marked ventilatory embarrassment. As there has been no previous study of physiologic changes related to LS in weightlessness, we studied anesthetized pigs in parabolic flight.Parabolic flight research laboratory.Five anesthetized Yorkshire pigs.Subjects were transported from an animal care facility and secured aboard an aircraft capable of generating hypergravity and weightlessness. Mechanical ventilation was performed using pressure control and positive end-expiratory pressure at 15 and 2 cm H2O, respectively; rate 12 breaths/min. Three abdominal conditions were used during LS: insufflation to produce IAH, abdominal wall retraction (AWR), and no abdominal wall manipulation (baseline). During each parabola breath by breath-tidal volumes (Vt) were recorded by a transport ventilator (HT-50 Newport Medical).Least square means (LS-means) of weight corrected Vt (milliliter per kilogram) by gravity (g) and abdominal condition were determined using a mixed effects model for repeated measures analysis. Increasing gravity (g) consistently reduced Vt (p = 0.0011) as did insufflation (p0.0001). In 1g, Vt (LS-mean 13.7, 95% confidence interval [CI]: 12.4-15.0) was relatively unaffected by AWR (LS-mean 12.8, 95% CI: 11.5-14.00), but markedly decreased by IAH (LS-mean 10.00, 95% CI: 8.9-11.1), an effect accentuated in hypergravity (LS-mean 8.1, 95% CI: 6.4-9.8). In weightlessness, Vt reduction during insufflation was near obviated (LS-mean 12.3, 95% CI: 10.6-14.1), and AWR regularly but inconsistently increased the Vt above 1g baseline (LS-mean 13.7, 95% CI: 11.7-15.8).Weightlessness protects against thoracic compliance changes that are inherent in IAH during induced pneumoperitoneum in gravity. The technique-related physiologic cost of performing LS in space deconditioned astronauts should be incorporated into design concepts for space surgery systems.

It is likely humans will venture beyond the relative safety of low earth orbit (LEO) during the next century, in space-faring journeys termed exploration class missions (ECMs). These missions will include manned missions to the Moon and, ultimately, Mars. Such a mission to Mars could entail a period of years in which space travelers would be unable to quickly return to Earth in the event of a serious surgical condition. These medical care challenges are greater than the engineering ones. Space medicine will always be limited by logistical factors such as limitations in weight, volume, power, and crew training. It will be driven by a focus on conditions that are most likely to occur, or would have the most impact on the crewmembers and mission. A human surgical event has not yet occurred in space, though injury has been ranked at the highest level of concern regarding the probable incidence versus impact and is considered a critical problem for which no reliable countermeasures exist in the National Aeronautics and Space Administration (NASA) Bioastronautics Critical Path Roadmap for long-duration, human space exploration.

Telemedicine has been used to support care at a distance through the use of expensive equipment and broadband communication links. In the past, the operating room has been an isolated environment that has been relatively inaccessible for real-time consultation. Recent technological advances have permitted videoconferencing over low-bandwidth, inexpensive Internet connections. If these connections are shown to provide adequate video quality for surgical applications, low-bandwidth telemedicine will revolutionize surgical practice by enabling remote real-time surgical consultation. Many of the regions around the world that have the most need for advanced surgical mentoring can least afford it. Although expensive broadband network links such as integrated services digital network (ISDN), local area networks (LANs), and dedicated T-1 lines have provided ample throughput for acceptable video image quality in recent years, the Internet has opened new doors for inexpensive alternatives. Early work by NASA demonstrated the usefulness of the Internet for telemedicine applications. 1 Similar work was also conducted using plain old telephone system (POTS) from the jungles of Ecuador. 2 In both cases, low bandwidth proved to be very useful for telemedicine applications. Internet-2 has been shown to provide high-resolution images, 3 but Internet-2 is simply another broadband technology, which will not be broadly available in the foreseeable future in most regions of the world. By using the ordinary telephone and a dial-up account to a local or global Internet service provider (ISP), a reliable remote node network can be established easily and affordably. The Internet has been successfully shown to be a useful and effective tool in supporting telemedicine on an international scale. 4,5 Over low-bandwidth connections such as dial-up, many Internet applications such as e-mail or web browsing are completely adequate. However, transmitting video over this type of connection is more difficult because of the synchronous data transfer rate and high degrees of compression. A series of experiments were performed to determine whether the quality of video images transmitted over Internet protocol (IP) connections were adequate to support surgical applications.