Assessing visualization in robotic-assisted surgery: demystifying a misty lens.

Despite major technological advancements in robotic-assisted laparoscopic surgery (RAS), there remain shortcomings yet to be addressed. This study assesses the prevalence of suboptimal vision in minimally invasive RAS and corresponding factors regarding related surgical conditions. 45 minimally invasive robotic surgeries, performed using Da Vinci XI, were observed across three surgical subspecialties: general, urology, and OB/GYN. Lens occlusion events were monitored and defined as the presence of a visual distortion caused by debris deposition on the scope lens. Lens occlusions and cleanings, and "active instrumentation" were recorded. Descriptive statistics summarized duration-based variables, and one-factor ANOVA compared the presence of active instrumentation. Cases averaged 127 ± 76 min. Active instrumentation ANOVA during lens occlusions demonstrated significant variation between categories (F7, 256 = 11.63, p = 2.558e-13). Post hoc Tukey HSD found electrocautery devices were active significantly more during occlusion events (37.9%) than other instruments. On average, lens cleaning occurred every 36.5 ± 39.8 min despite lens occlusion occurring every 24.5 ± 15.7 min. Of the operative time observed, 41.4% ± 28.1% was conducted with visual distortion. 1.16% ± 0.97% of time observed was spent cleaning. Although only 1.16% of operative time was spent cleaning, surgeons experienced suboptimal conditions for nearly 35× the time it would take the clear lens, potentially indicating a tendency to avoid cleaning the lens to disrupt surgery. Future research may examine the impact of occluded visualization and lens cleaning on other aspects of surgery.

Stop the leak!: Mitigating potential exposure of aerosolized COVID-19 during laparoscopic surgery.

BACKGROUND: Viral particles have been shown to aerosolize into insufflated gas during laparoscopic surgery. In the operating room, this potentially exposes personnel to aerosolized viruses as well as carcinogens. In light of circumstances surrounding COVID-19 and a concern for the safety of healthcare professionals, our study seeks to quantify the volumes of gas leaked from dynamic interactions between laparoscopic instruments and the trocar port to better understand potential exposure to surgically aerosolized particles. METHODS: A custom setup was constructed to simulate an insufflated laparoscopic surgical cavity. Two surgical instrument use scenarios were examined to observe and quantify opportunities for insufflation gas leakage. Both scenarios considered multiple configurations of instrument and trocar port sizes/dimensions: (1) the full insertion and full removal of a laparoscopic instrument from the port and (2) the movement of the scope within the port, recognized as "dynamic interaction", which occurs nearly 100% of the time over the course of any procedure. RESULTS: For a 5 mm instrument in a 5 mm trocar, the average volume of gas leaked during dynamic interaction and full insertion/removal scenarios were 43.67 and 25.97 mL of gas, respectively. Volume of gas leaked for a 5 mm instrument in a 12 mm port averaged 41.32 mL and 29.47 for dynamic interaction vs. instrument insertion and removal. Similar patterns were shown with a 10 mm instrument in 12 mm port, with 55.68 mL for the dynamic interaction and 58.59 for the instrument insertion/removal. CONCLUSIONS: Dynamic interactions and insertion/removal events between laparoscopic instruments and ports appear to contribute to consistent leakage of insufflated gas into the OR. Any measures possible taken to reduce OR gas leakage should be considered in light of the current COVID-19 pandemic. Minimizing laparoscope and instrument removal and replacement would be one strategy to mitigate gas leakage during laparoscopic surgery.

Quantification of the Capacity for Cold-Induced Thermogenesis in Young Men With and Without Obesity.

OBJECTIVE: Cold exposure increases energy expenditure (EE) and could have a role in combating obesity. To understand this potential, we determined the capacity for cold-induced thermogenesis (CIT), the EE increase above the basal metabolic rate at the individualized coldest tolerable temperature before overt shivering. DESIGN: During a 13-day inpatient protocol, we quantitated the EE of 12 lean men and 9 men with obesity at various randomly ordered ambient temperatures in a room calorimeter. Subjects underwent brown fat imaging after exposure to their coldest tolerable temperature. RESULTS: CIT capacity was 300 ± 218 kcal/d (mean ± SD) or 17 ± 11% in lean men and 125 ± 146 kcal/d or 6 ± 7% in men with obesity (P = 0.01). The temperature below which EE increased, lower critical temperature (Tlc), was warmer in lean men than men with obesity (22.9 ± 1.2 vs 21.1 ± 1.7°C, P = 0.03), but both had similar skin temperature (Tskin) changes and coldest tolerable temperatures. Whereas lean subjects had higher brown fat activity, skeletal muscle activity increased synchronously with CIT beginning at the Tlc in both groups, indicating that muscle is recruited for CIT in parallel with brown fat, not sequentially after nonshivering thermogenesis is maximal. CONCLUSIONS: Despite greater insulation from fat, men with obesity had a narrower range of tolerable cool temperatures available for increasing EE and less capacity for CIT than lean men, likely as a result of greater basal heat production and similar perception to Tskin cooling. Further study of the reduced CIT capacity in men with obesity may inform treatment opportunities for obesity.

Effect of mechanical optical clearing on near-infrared spectroscopy.

Near-infrared Spectroscopy (NIRS) is a broadly utilized technology with many emerging applications including clinical diagnostics, sports medicine, and functional neuroimaging, to name a few. For functional brain imaging NIR light is delivered at multiple wavelengths through the scalp and skull to the brain to enable spatial oximetry measurements. Dynamic changes in brain oxygenation are highly correlated with neural stimulation, activation, and function. Unfortunately, NIRS is currently limited by its low spatial resolution, shallow penetration depth, and, perhaps most importantly, signal corruption due to light interactions with superficial non-target tissues such as scalp and skull. In response to these issues, we have combined the non-invasive and rapidly reversible method of mechanical tissue optical clearing (MOC) with a commercially available NIRS system. MOC utilizes a compressive loading force on tissue, causing the lateral displacement of blood and water, while simultaneously thinning the tissue. A MOC-NIRS Breath Hold Test displayed a ∼3.5-fold decrease in the time-averaged standard deviation between channels, consequentially promoting greater channel agreement. A Skin Pinch Test was implemented to negate brain and muscle activity from affecting the recorded signal. These results displayed a 2.5-3.0 fold increase in raw signal amplitude. Existing NIRS instrumentation has been further integrated within a custom helmet device to provide a uniform force distribution across the NIRS sensor array. These results showed a gradual decrease in time-averaged standard deviation among channels with an increase in applied pressure. Through these experiments, and the development of the MOC-NIRS helmet device, MOC appears to provide enhancement of NIRS technology beyond its current limitations.