Purpose: The calculation of the intraperitoneal organ surface area is important for understanding their anatomical structure and for conducting basic and clinical studies on diseases related to the peritoneum. To measure the intraperitoneal surface area in a living body by applying artificial intelligence (AI) techniques to the abdominal cavity using computed tomography and to prepare clinical indicators for application to the abdominal cavity. Methods: Computed tomography images of ten adult males and females with a healthy body mass index and ten adults diagnosed with colon cancer were analyzed to determine the peritoneal and intraperitoneal surface areas of the organs. The peritoneal surface was segmented and three-dimensionally modeled using AI medical imaging software. In addition to manual work, three-dimensional editing, filtering, and connectivity checks were performed to improve work efficiency and accuracy. The colon and small intestine surface areas were calculated using the mean length and diameter. The abdominal cavity surface area was defined as the sum of the intraperitoneal area and the surface areas of each organ. Results: The mean peritoneal surface area of all participants was measured as 10,039 ± 241 cm2 (males 10,224 ± 171 cm2 and females 9,854 ± 134 cm2). Males had a 3.7% larger peritoneal surface area than females, with a statistically significant difference (P < 0.001). Conclusion The abdominal cavity surface area can be measured using AI techniques and is expected to be used as basic data for clinical applications.

Purpose: Studies on the appropriate amount of anti-adhesive agents for preventing postoperative adhesion are lacking. This animal study aimed to investigate the distribution of an anti-adhesive agent in the abdominal cavity and estimate the necessary amount to cover the entire cavity. Methods: Fluorescent dye Flamma-552 was conjugated to Guardix-sol to create Guardix-Flamma, which was laparoscopically applied to the abdominal cavity of two 10-kg pigs in different amounts: 15 mL for G1 and 35 mL for G2. After 24 hours, the distribution of Guardix-Flamma was examined under the near-infrared mode of the laparoscope, and the thickness was measured in tissues from the omentum, small, and large intestine by immunohistochemistry. Results: The average area of the abdominal cavity in 10 kg pigs was 2,755 cm2. Guardix-Flamma fluorescence was detected in the greater omentum, ascites in the pelvis, and right quadrant area in G1, whereas in G2, it was detected everywhere. On average, the total thickness of G1 and G2 were 12.68 ± 9.80 μm and 18.16 ± 15.57 μm, respectively. Guardix-Flamma thickness applied to the omentum, small, and large intestines of G2 were 1.31-, 1.45-, and 1.49-times thicker than those of G1, respectively, and were all statistically significant (P < 0.05). Conclusion The entire abdominal cavity of the 10 kg pig was not evenly covered with 15 mL of Guardix. Although 35 mL of Guardix is sufficient to cover the same area with an average thickness of 18 µm, further studies should evaluate the minimum thickness required for an effective anti-adhesive function.

Purpose: Curative treatment is challenging in patients with locally advanced rectal cancer and unresectable metastases. The aim of this study was to evaluate the clinical outcomes of short-course radiotherapy (RT) followed by systemic chemotherapy for patients with rectal cancer with mesorectal fascia (MRF) involvement and unresectable distant metastases. Methods: The study included consecutive patients diagnosed as having metastatic mid-to-low rectal cancer treated with short-course RT followed by systemic chemotherapy for conversion radical or palliative surgery between 2014 and 2019 at Gil Medical Center. The patients had primary rectal tumors involving the MRF and unresectable distant metastases. The treatment strategies were determined in a multidisciplinary team discussion. Results: Seven patients (five men and two women) underwent short-course RT (5 × 5 Gy) and preoperative systemic chemotherapy. The median age was 68 years (range, 46–84 years), and the median distance from the anal verge to the primary tumor was 6.0 cm (range, 2.0–9.0 cm). During the median follow-up period of 29.4 months, three patients underwent conversion radical surgery with R0 resection, two underwent palliative surgery, and two could not undergo surgery. No postoperative major morbidity or mortality occurred. The patients who underwent conversion complete radical surgery showed good long-term survival outcomes, with an overall survival time of 29.4–48.8 months and progression-free survival time of 14.7–41.1 months. Conclusion Short-course RT followed by systemic chemotherapy could provide patients with unresectable stage IV rectal cancer a chance to undergo to conversion radical surgery with good long-term survival outcomes.

Purpose: Under the South Korea’s unique health insurance structure, any new surgical technology must be evaluated first by the government in order to consider whether that particular technology can be applied to patients for further clinical trials as categorized as ‘New Health Technology,’ then potentially covered by the insurance sometime later. The aim of this meta-analysis was to assess the safety and efficacy of transanal total mesorectal excision (TaTME) for rectal cancer, activated by the National Evidence-based Healthcare Collaborating Agency (NECA) TaTME committee. Methods: We systematically searched Ovid-MEDLINE, Ovid-Embase, Cochrane, and Korean databases (from their inception until August 31, 2019) for studies published that compare TaTME with laparoscopic total mesorectal excision (LaTME). End-points included perioperative and pathological outcomes. Results: Sixteen cohort studies (7 for case-matched studies) were identified, comprising 1,923 patients (938 TaTMEs and 985 LaTMEs). Regarding perioperative outcomes, the conversion rate was significantly lower in TaTME (risk ratio, 0.19; 95% confidence interval, 0.11–0.34; P < 0.001); whereas other perioperative outcomes were similar to LaTME. There were no statistically significant differences in pathological results between the 2 procedures. Conclusion Our meta-analysis showed comparable results in preoperative and pathologic outcomes between TaTME and LaTME, and indicated the benefit of TaTME with low conversion. Extensive evaluations of well-designed, multicenter randomized controlled trials are required to come to unequivocal conclusions, but the results showed that TaTME is a potentially beneficial technique in some specific cases. This meta-analysis suggests that TaTME can be performed for rectal cancer patients as a ‘New Health Technology’ endorsed by NECA in South Korea.

Purpose: Under the South Korea’s unique health insurance structure, any new surgical technology must be evaluated first by the government in order to consider whether that particular technology can be applied to patients for further clinical trials as categorized as ‘New Health Technology,’ then potentially covered by the insurance sometime later. The aim of this meta-analysis was to assess the safety and efficacy of transanal total mesorectal excision (TaTME) for rectal cancer, activated by the National Evidence-based Healthcare Collaborating Agency (NECA) TaTME committee. Methods: We systematically searched Ovid-MEDLINE, Ovid-Embase, Cochrane, and Korean databases (from their inception until August 31, 2019) for studies published that compare TaTME with laparoscopic total mesorectal excision (LaTME). End-points included perioperative and pathological outcomes. Results: Sixteen cohort studies (7 for case-matched studies) were identified, comprising 1,923 patients (938 TaTMEs and 985 LaTMEs). Regarding perioperative outcomes, the conversion rate was significantly lower in TaTME (risk ratio, 0.19; 95% confidence interval, 0.11–0.34; P < 0.001); whereas other perioperative outcomes were similar to LaTME. There were no statistically significant differences in pathological results between the 2 procedures. Conclusion Our meta-analysis showed comparable results in preoperative and pathologic outcomes between TaTME and LaTME, and indicated the benefit of TaTME with low conversion. Extensive evaluations of well-designed, multicenter randomized controlled trials are required to come to unequivocal conclusions, but the results showed that TaTME is a potentially beneficial technique in some specific cases. This meta-analysis suggests that TaTME can be performed for rectal cancer patients as a ‘New Health Technology’ endorsed by NECA in South Korea.

Purpose: This study aimed to investigate the clinical outcomes after totally implantable access port (TIAP) implantation performed by general surgery residents in patients with colorectal cancer. Methods: A total of 291 consecutive patients who underwent TIAP implantations were evaluated. The patients were divided into threegroups: second-, third-, and fourth-grade residents. Results: The mean follow-up was 22.1 months (range, 1–87 months). The total times of operation, puncture, and cannulation decreased as the resident grade increased (P<0.001). Early complications significantly decreased with higher resident grades (P=0.039). The non-use of ultrasonography and non-use of C-arm were identified as independent risk factors for complications. Resident grades between second and third (P=0.005) and between second and fourth (P=0.041) were identified as independent risk factors for optimal tip position. Conclusion TIAP implantation can be safely and effectively performed by residents. Low-grade residents were associated with early complications.

Purpose: This study aimed to investigate the clinical outcomes after totally implantable access port (TIAP) implantation performed by general surgery residents in patients with colorectal cancer. Methods: A total of 291 consecutive patients who underwent TIAP implantations were evaluated. The patients were divided into threegroups: second-, third-, and fourth-grade residents. Results: The mean follow-up was 22.1 months (range, 1–87 months). The total times of operation, puncture, and cannulation decreased as the resident grade increased (P<0.001). Early complications significantly decreased with higher resident grades (P=0.039). The non-use of ultrasonography and non-use of C-arm were identified as independent risk factors for complications. Resident grades between second and third (P=0.005) and between second and fourth (P=0.041) were identified as independent risk factors for optimal tip position. Conclusion TIAP implantation can be safely and effectively performed by residents. Low-grade residents were associated with early complications.

PURPOSE: The optimal treatment for synchronous liver metastasis (LM) from colorectal cancer (CRC) depends on various factors. The present study was intended to investigate the oncologic outcome according to the time of resection of metastatic lesions. METHODS: Data from patients who underwent treatment with curative intent for primary CRC and synchronous LM between 2004 and 2009 from 9 university hospitals in Korea were collected retrospectively. One hundred forty-three patients underwent simultaneous resection for primary CRC and synchronous LM (simultaneous surgery group), and 65 patients were treated by 2-stage operation (staged surgery group). RESULTS: The mean follow-up length was 41.2 ± 24.6 months. In the extent of resection for hepatic metastasis, major hepatectomy was more frequently performed in staged surgery group (33.8% vs. 8.4%, P < 0.001). The rate of severe complications of Clavien-Dindo classification grade III or more was not significantly different between the 2 groups. The 3-year overall survival (OS) rate was 85.0% in staged surgery group and 69.4% in simultaneous surgery group (P = 0.013), and the 3-year recurrence-free survival (RFS) rate was 46.4% in staged surgery group and 30.2% in simultaneous surgery group (P = 0.143). In subgroup analysis based on the location of primary CRC, the benefit of staged surgery for OS and RFS was clearly shown in rectal cancer (P = 0.021 and P = 0.015). CONCLUSION: Based on our results, staged surgery with or without neoadjuvant chemotherapy should be considered for resectable synchronous LM from CRC, especially in rectal cancer, as a safe and fairly promising option.
Classification ; Colorectal Neoplasms ; Drug Therapy ; Follow-Up Studies ; Hepatectomy ; Hospitals, University ; Humans ; Korea ; Liver ; Neoplasm Metastasis ; Rectal Neoplasms ; Retrospective Studies

Metastatic colorectal cancer is rare and its origins are difficult to define if the gross features of colorectal cancer mimic primary colorectal cancer. However, accurate diagnosis is essential because the treatment and prognosis may vary depending on the origin of the cancer. This report is about a 74-year-old female patient with metastatic sigmoid colon cancer of ovarian origin that mimicked primary sigmoid colon cancer. She spent a 3-year period disease-free from ovarian cancer after surgery and adjuvant chemotherapy. At the time of initial diagnosis, the cancer was diagnosed as a primary sigmoid colon cancer, because the cancer appeared to be a solitary intra-luminal fungating mass. However, the final pathologic result showed that the cancer was metastatic sigmoid colon cancer of ovarian origin and it was confirmed by immunohistochemical staining of cytokeratins-7, -20, and Wilms tumor-1. Therefore, even if colorectal cancer is a single intra-luminal lesion, patients should be suspected of having metastatic colorectal cancer if they have other cancer histories. At this time, immunohistochemical staining using various cancer markers may be a useful tool to distinguish the origin of cancer.
Aged ; Chemotherapy, Adjuvant ; Colon ; Colonic Neoplasms ; Colorectal Neoplasms ; Diagnosis ; Female ; Humans ; Immunohistochemistry ; Neoplasm Metastasis ; Ovarian Neoplasms ; Prognosis ; Sigmoid Neoplasms

PURPOSE: The status of tumor regression in rectal cancer after neoadjuvant concurrent chemoradiotherapy (CCRT) has significant effect on tumor recurrence and patient survival. The aim of this study was to evaluate the long-term oncologic outcomes of rectal cancer patients presenting complete response or down-staging of rectal cancer compared to patients with non-response after neoadjuvant therapy in advanced mid-to-lower rectal cancer.METHODS: We retrospectively reviewed 79 patients with stage II/III mid-to-lower rectal cancer following neoadjuvant CCRT between March 2003 and April 2012. Patients were classified into three groups according to down-staging tumor response after neoadjuvant CCRT: complete response group (CRG), partial response group (PRG), and non-response group (NRG).RESULTS: Of the 79 patients in the study, eight (10.1%), 31 (39.2%), and 40 (50.7%) were classified as CRG, PRG, and NRG, respectively. Median follow-up period was 57 months. There was significant difference in local recurrence (P=0.012) between the three groups, yet there was no significant difference in overall survival (CRG, 100%; PRG, 82.5%; NRG, 74.0%; P=0.244). There was a significant difference in disease-free survival (CRG, 100%; PRG, 90.1%; NRG, 57.7%; P=0.006).CONCLUSION: Tumor response with complete response or down-staging provided better oncologic outcomes in terms of disease-free survival and local recurrence in locally advanced rectal cancer patients.
Chemoradiotherapy ; Disease-Free Survival ; Follow-Up Studies ; Humans ; Neoadjuvant Therapy ; Rectal Neoplasms ; Recurrence ; Retrospective Studies