Artificial intelligence (AI) has made significant progress in recent years, and many medical fields are attempting to introduce AI technology into clinical practice. Currently, much research is being conducted to evaluate that AI can be incorporated into surgical procedures to make them safer and more efficient, subsequently to obtain better outcomes for patients.In this paper, we review basic AI research regarding surgery and discuss the potential for implementing AI technology in gastric cancer surgery. At present, research and development is focused on AI technologies that assist the surgeon's understandings and judgment during surgery, such as anatomical navigation. AI systems are also being developed to recognize in which the surgical phase is ongoing. Such a surgical phase recognition systems is considered for effective storage of surgical videos and education, in the future, for use in systems to objectively evaluate the skill of surgeons. At this time, it is not considered practical to let AI make intraoperative decisions or move forceps automatically from an ethical standpoint, too. At present, AI research on surgery has various limitations, and it is desirable to develop practical systems that will truly benefit clinical practice in the future.

Between March 1985 and May 1988 we performed valve replacement to 86 cases using 92 Duromedics prosthetic valves in the atrioventricular position. Long term results were obtained, we examined the problem (especially thrombosed valve). The cumulative follow-up was 313.6 patients-year (p-y). The 6-year actuarial survival rate including early mortality was 83.4±4.1%. The valve-related complications were as follows; peripheral embolism 3 cases (1.0%/p-y), thrombosed valve 7 cases (2.2%/p-y), hemorrhage and paravalvular leakage each 1 case (0.3%/p-y). All valve-related complications were 12 cases (3.8%/p-y). Reoperation for valve-related complications were 5 cases (1.6%/p-y), it was all to thrombosed prosthetic valve. Thrombosed valve were seen 7 cases (4 cases in mitral, 3 cases in tricuspid position). The event free rate of thrombosed valve was 89.1±4.0%. It was high incidence in tricuspid position. We concluded that it was necessary to be done early reoperation the time of fixed with one leaflet alone.

Purpose: We evaluated the oncological outcomes of bridge to surgery (BTS) using stent compared with surgery alone for obstructive colorectal cancer. Methods: Consecutive patients who underwent curative resection for stages II to III obstructive colorectal cancer at our institution from January 2009 to March 2020, were registered retrospectively and divided into 43 patients in the BTS group and 65 patients in the surgery alone group. We compared the surgical and oncological outcomes between the 2 groups. Results: Stent-related perforation did not occur. One patient in whom the stent placement was unsuccessful underwent emergency surgery with poor decompression (clinical success rate, 97.7%). The pathological characteristics were not significantly different between the groups. The following surgical outcomes in the BTS group were superior to those in the surgery alone group; nonemergency surgery (P<0.001), surgical approach (P=0.006), and length of hospital stay (P=0.020). The median follow-up time was 44.9 months (range, 1.1–126.5 months). The 3-year relapse-free survival rates were 68.4% and 58.2% (P=0.411), and the overall survival rates were 78.3% and 88.2% (P=0.255) in the surgery alone and BTS groups, respectively. The 3-year locoregional recurrence rates were 10.2% and 8.0% (P=0.948), and distant metastatic recurrence rates were 13.3% and 30.4% (P=0.035) in the surgery alone and BTS groups, respectively. Conclusion This study revealed that BTS with stent may be associated with a higher frequency of distant metastatic recurrence. Stent for stages II to III obstructive colorectal cancer potentially worsens oncological outcomes.