Even though rotational intraperitoneal pressurized aerosol chemotherapy (RIPAC) has been developed to improve the distribution and penetration depth of anti-cancer agents by pressurized intraperitoneal aerosol chemotherapy (PIPAC), the optimal nozzle position and patient’s posture have not been investigated. Thus, we used nine pigs weighing 50–60 kg, and sprayed 150 mL of 1% methylene blue as an aerosol through the nozzle, DreamPen® (Dreampac Corp., Wonju, Republic of Korea), with a flow rate of 0.6 ml/min under a pressure of 140 to 150 psi for RIPAC in six and three pigs with supine and Trendelenburg positions, respectively. When we evaluated its distribution and penetration depth, even distribution among 13 regions of the abdomen was observed in three pigs with Trendelenburg position regardless of the depth of the nozzle. Regarding penetration depth, the numbers of regions with maximal penetration depth were high in the 2 cm depth of the nozzle with supine position (n = 5) and the 4 cm depth with Trendelenburg position (n = 3). Conclusively, even distribution and maximal penetration of anti-cancer agents can be expected during RIPAC in the medium depth (4 cm) between the nozzle inlet and the visceral peritoneum located on the opposite side of it and the Trendelenburg position.

Introduction Even though the injection of diluted vasopressin into the uterus is expected to reduce intraoperative bleeding with decreased adverse effects during robot-assisted laparoscopic myomectomy (RALM), there is a lack of relevant trials to show its effect and safety. Thus, this study was designed to compare the effect and safety of vasopressin injection on bleedings based on dilution levels of vasopressin with constant volumes during RALM. Methods and analysis This is a randomised controlled pilot trial, where a total of 39 patients will be randomly divided into three experimental groups in a 1:1:1 ratio. All patients will be classified into the three groups based on the dilution level of vasopressin: group 1—a solution prepared by mixing 20 units of vasopressin with 100 mL of normal saline to make a total of 100 mL; group 2—a solution prepared by mixing 20 units of vasopressin with 200 mL of normal saline to make a total of 100 mL and group 3—a solution prepared by mixing 20 units of vasopressin with 400 mL of normal saline to make a total of 100 mL. During RALM, we will inject diluted vasopressin at different concentrations with a total of 100 mL. As the primary endpoint, estimated blood loss would be compared. As secondary endpoints, we will check the level of haemoglobin and haematocrit, operation time, amount of transfusion, and the period of hospitalisation. In addition, we will check other complications related to vasopressin injection. Ethics and dissemination This pilot study has been approved by the Institutional Review Board of the Seoul National University Hospital (No. H-2011-107-1174). All potential subjects will be provided written informed consent. The results of this study will be published in peer-reviewed journals and be presented at academic conferences. Trial registration numbers NCT04874246 and CKCT0006225.

Objective We used paclitaxel and cisplatin, known to be effective in intraperitoneal chemotherapy, in a novel prototype of rotational intraperitoneal pressurized aerosol chemotherapy (RIPAC) and evaluated the pharmacokinetics, tissue concentrations, and toxicities in a pig model. Methods We developed RIPAC, including the nozzle with the conical pendulum motion, and used 10% of intravenous doses of paclitaxel and cisplatin. We used high-performance liquid chromatography followed by tandem mass spectrometry to analyze serum and tissue concentrations. We applied a non-compartment model to study pharmacokinetics to analyze the time-dependent serum concentrations measured before RIPAC to 48 hours. We evaluated the difference in tissue concentrations between twelve peritoneal regions by the modified peritoneal cancer index. For evaluating toxicities, we observed hepatic and renal function until 4 days after RIPAC. Results Six pigs underwent RIPAC using paclitaxel (n=3) and cisplatin (n=3). The peak serum concentration (C max ) and the area under the curve were higher for cisplatin, while the time to the peak serum concentration (T max ) was longer for paclitaxel. Moreover, the parietal peritoneum showed higher tissue concentrations than the visceral peritoneum, and the ratio of tissue to serum concentrations using C max was higher for paclitaxel (172.2–6,237.9) than for cisplatin (0.1–9.3). However, there were no renal and hepatic toxicities after RIPAC with paclitaxel or cisplatin. Conclusion Delayed absorption of paclitaxel sprayed by RIPAC into the peritoneum to the bloodstream may lead to higher tissue concentrations at different regions and lower serum concentrations than cisplatin.

BACKGROUND Techniques utilizing artificial intelligence (AI) are rapidly growing in medical research and development, especially in the operating room. However, the application of AI in the operating room has been limited to small tasks or software, such as clinical decision systems. It still largely depends on human resources and technology involving the surgeons’ hands. Therefore, we conceptualized AI-based solo surgery (AISS) defined as laparoscopic surgery conducted by only one surgeon with support from an AI-based surgical assistant system, and we performed an electronic survey on the clinical desire for such a system. OBJECTIVE This study aimed to evaluate the experiences of surgeons who have performed laparoscopic surgery, the limitations of conventional laparoscopic surgical systems, and the desire for an AI-based surgical assistant system for AISS. METHODS We performed an online survey for gynecologists, urologists, and general surgeons from June to August 2017. The questionnaire consisted of six items about experience, two about limitations, and five about the clinical desire for an AI-based surgical assistant system for AISS. RESULTS A total of 508 surgeons who have performed laparoscopic surgery responded to the survey. Most of the surgeons needed two or more assistants during laparoscopic surgery, and the rate was higher among gynecologists (251/278, 90.3%) than among general surgeons (123/173, 71.1%) and urologists (35/57, 61.4%). The majority of responders answered that the skillfulness of surgical assistants was “very important” or “important.” The most uncomfortable aspect of laparoscopic surgery was unskilled movement of the camera (431/508, 84.8%) and instruments (303/508, 59.6%). About 40% (199/508, 39.1%) of responders answered that the AI-based surgical assistant system could substitute 41%-60% of the current workforce, and 83.3% (423/508) showed willingness to buy the system. Furthermore, the most reasonable price was US $30,000-50,000. CONCLUSIONS Surgeons who perform laparoscopic surgery may feel discomfort with the conventional laparoscopic surgical system in terms of assistant skillfulness, and they may think that the skillfulness of surgical assistants is essential. They desire to alleviate present inconveniences with the conventional laparoscopic surgical system and to perform a safe and comfortable operation by using an AI-based surgical assistant system for AISS.

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