A new scope warmer/cleaner for laparoscopic surgery: a disposable hot pack.

BACKGROUND: Fogging and staining of a laparoscope lens negatively impact surgical visualization. We hypothesized that the disposable hot pack could not only warm but also clean laparoscopes. Hence, this study verified and developed the disposable hot pack with anti-fogging and cleaning function. MATERIAL AND METHODS: The laparoscope was inserted into a swine abdominal cavity for five minutes. Then, the laparoscopic tip was heated with 65 °C saline or the folded disposable hot pack with nonwoven fabric coated surfactant for ten seconds (n = 15). Also, a laparoscopic tip with dirt was wiped with the prototype or conventional gauze for 10 s (n = 10). The dirt, fogging, and temperature of the laparoscopic tip were respectively evaluated after the laparoscope was inserted into the abdominal cavity. RESULTS: The laparoscopic tip temperature five minutes after insertion into the abdominal cavity was similar (31.1 °C vs 31.2 °C, p = 0.748) and there was no fogging in both methods. The conventional gauze had significantly less temperature of the laparoscopic tip after cleaning and higher fogging occurrence than the prototype (29.5 °C vs 34.0 °C, p < 0.001, 30% vs 0%, p = 0.030, respectively), although there was no dirt left after both methods. CONCLUSION: The disposable hot pack has a strong potential as an anti-fogging and cleaning device for use during laparoscopic surgery.

Mechanism underlying lens fogging and its countermeasure in laparoscopic surgery.

BACKGROUND: During laparoscopic surgery, visualization is fogged due to the influence of temperature. Fogging on the laparoscopic lens heightens the difficulty of the procedure. Therefore, the aim of this study was to analyse thermodynamics in laparoscopy. MATERIAL AND METHODS: A temperature sensor was attached to the laparoscopic tip and the abdominal cavity of five swine under general anaesthesia. The laparoscope was inserted into the abdominal cavity for five minutes after heating its tip with 65 °C saline for 10-300 s. The defogged laparoscope was wiped at room temperature for 10-300 s. Then, the laparoscope was inserted into the abdominal cavity for five minutes. RESULTS: The temperature five minutes after insertion was similar for the 10-300 s heating durations (approximately 32.0 °C). There was no fogging when the laparoscope was wiped for 10-30 s. Two fogging events occurred when it was wiped for 60 s (temperature difference: -3.5 °C, -4.6 °C). Five fogging events were observed immediately after insertion when it was wiped for 300 s. CONCLUSION: This study showed that the heating time was more than ten seconds to prevent fogging. We found that fogging occurred when the laparoscopic tip temperature was 3.5 °C lower than the abdominal cavity temperature.