Evaluation of the advantage of surgeons certified by the endoscopic surgical skill qualification system participating in laparoscopic low anterior rectal resection.

Background: A technical qualification system was developed in 2004 by the Japan Society for Endoscopic Surgery. An analysis of the EnSSURE study on 3188 stage II-III rectal cancer patients, which was performed by including the participation of qualified surgeons as assistants and advisers without restricting their participation as operators, revealed that the participation of technically qualified surgeons in surgery improved the technical and oncological safety of laparoscopic rectal resection. Aim: This secondary retrospective analysis of the EnSSURE study examined the advantage of qualified surgeons participating in laparoscopic low anterior resection (LAR). Methods: The outcomes of low anterior resection were compared between groups with and without the participation of surgeons qualified by the Endoscopic Surgical Skill Qualification System (Q and non-Q groups, respectively). We used propensity score matching to generate paired cohorts at a one-to-one ratio. The postoperative complication rate, short-term results (hemorrhage volume, operative time, number of dissected lymph nodes, open conversion rate, intraoperative complication rate, and R0 resection rate), and long-term results (disease-free survival rate, local recurrence rate, and overall survival rate) were evaluated. Results: The frequencies of postoperative complications, anastomotic bleeding, and intraperitoneal abscess were significantly lower, the operative time was significantly shorter, the postoperative hospital stay was significantly shorter, and the number of dissected lymph nodes was higher in the Q group. No significant differences were observed in disease-free survival, local recurrence, or overall survival rate rates between the groups. Conclusion: The participation of qualified surgeons in LAR is technically advantageous.

Valley Pseudospin Polarized Evanescent Coupling between Microwave Ring Resonator and Waveguide in Phononic Topological Insulators.

A coupled ring-waveguide structure is at the core of bosonic wave-based information processing systems, enabling advanced wave manipulations such as filtering, routing, and multiplexing. However, its miniaturization is challenging due to momentum conservation issues in rings with larger curvature that induce significant backscattering and radiation leakage and hampering stable operation. Here, we address it by taking an alternative approach of using topological technology in wavelength-scale and microwave ring-waveguide coupled systems built in nanoengineered phononic crystals. Our approach, which leverages pseudospin conservation in valley topological systems, eliminates phonon backscattering and achieves directional evanescent coupling. The resultant hypersonic waves in the tiny ring exhibit robust transport and resonant circulation. Furthermore, the ring-waveguide hybridization enables critical coupling, where valley-dependent ring-waveguide interference blocks the transmission. Our findings reveal the capability of topological phenomena for managing ultrahigh-frequency phonons in nano/microscale structures and pave the way for advanced phononic circuits in classical and quantum signal processing applications.

Primary Malignant Melanoma of the Esophagus Treated with Surgical Resection at an Early Stage.

Introduction: Primary malignant melanoma of the esophagus is a very rare disease with a poor prognosis. We herein report a patient with primary malignant melanoma of the esophagus who underwent surgical resection. Case Presentation: A 73-year-old female underwent an upper gastrointestinal endoscopy during follow-up for colonic diverticulitis. An endoscopic examination and constructed radiography revealed a slightly elevated black pigmented lesion in the upper esophagus and a black pigmented area in the esophagogastric junction. Through a preoperative endoscopic biopsy, she was diagnosed with malignant melanoma of the esophagus. We performed thoracoscopy-assisted and laparoscopy-assisted subtotal esophagectomy with lymphadenectomy. The surgical specimens were subjected to immunohistochemical analysis, resulting in a diagnosis of malignant melanoma. The tumor cells were positive for Melan-A and HMB-45 diffusely, supporting that diagnosis. We performed surgical resection in a case of primary malignant melanoma of the esophagus, and the patient has remained disease free for 2 years since the surgery. Conclusion: Early diagnosis and radical resection may be essential for long-term survival in patients with malignant melanoma of the esophagus.

Short- and Long-term Outcomes After Colonic Stent Insertion as a Bridge to Surgery in Elderly Colorectal Cancer Patients.

BACKGROUND/AIM: Colonic stents have been inserted as a bridge to surgery in patients with resectable colorectal cancer, allowing bowel decompression for systemic assessment and better preparation to avoid stoma construction. However, reports of short- and long-term prognoses for elderly patients remain limited. PATIENTS AND METHODS: This retrospective study reviewed 175 consecutive patients who underwent colonic stent insertion for bowel obstruction followed by curative colectomy. Patients were divided into those >80 years old (Old, n=49) and those <80 years old (Young, n=126). After propensity score matching, 41 patients in each group matched. RESULTS: Before matching, performance status was poorer (p<0.001), postoperative complication rate was higher (p=0.009), adjuvant chemotherapy rate was lower (p<0.001), and hospital stay was longer (p<0.001) in the Old group. After matching, adjuvant chemotherapy rate was lower (9.8% vs. 39.0%; p=0.003) and hospital stay was longer (14 vs. 12 days; p=0.029) in the Old group. Five-year relapse-free survival (42.9% vs. 68.8%; p=0.200), overall survival (66.3% vs. 87.7%; p=0.081), and cancer-specific survival (68.2% vs. 87.7%; p=0.129) rates were comparable between groups. CONCLUSION: Colorectal resection after colonic stent insertion is useful for elderly patients, with potential to reduce postoperative complication rates and achieve good long-term results with appropriate case selection.

Impact of institutional volume on short- and long-term outcomes after laparoscopic colectomy.

INTRODUCTION: The impact of institutional volume on postoperative outcomes after laparoscopic colectomy is still being debated. This study aimed to investigate whether differences in postoperative outcomes of laparoscopic colon resection exist between high- and low-volume centers. METHODS: Data were reviewed for 1360 patients who underwent laparoscopic colectomy for colon cancer between 2016 and 2022. Patients were divided according to whether they were treated at a high-volume center (≥100 colorectal surgeries annually; n = 947) or a low-volume center (<100 colorectal surgeries annually; n = 413). Propensity score matching was applied to balance covariates and minimize selection biases that could affect outcomes. Finally, 406 patients from each group were matched. RESULTS: After matching, patients from high-volume centers showed a higher number of retrieved lymph nodes (19 vs. 17, p < .001) and more frequent involvement of expert surgeons (98.3% vs. 88.4%, p < .001). Postoperative complication rates were similar between groups (p = .488). No significant differences between high- and low-volume centers were seen in relapse-free survival (88.8% each, p = .716) or overall survival (85.7% vs. 82.8%, p = .480). CONCLUSION: The present study suggests that in appropriately educated organizations, relatively safe procedures and good prognosis may be obtained for laparoscopic colectomy cases, regardless of institutional volume.

Short-term outcomes after laparoscopic colorectal cancer surgery in patients over 90 years old: a Japanese multicenter study.

BACKGROUND: The effect of laparoscopic surgery on short-term outcomes in colorectal cancer patients over 90 years old has remained unclear. METHODS: We reviewed 87 colorectal cancer patients aged over 90 years who underwent surgery between 2016 and 2022. Patients were divided into an open surgery group (n = 22) and a laparoscopic surgery group (n = 65). The aim of this study was to investigate the effect of laparoscopic surgery on postoperative outcome in elderly colorectal cancer patients, as compared to open surgery. RESULTS: Seventy-eight patients (89.7%) had comorbidities. Frequency of advanced T stage was lower with laparoscopic surgery (p = 0.021). Operation time was longer (open surgery 146 min vs. laparoscopic surgery 203 min; p = 0.002) and blood loss was less (105 mL vs. 20 mL, respectively; p < 0.001) with laparoscopic surgery. Length of hospitalization was longer with open surgery (22 days vs. 18 days, respectively; p = 0.007). Frequency of infectious complications was lower with laparoscopic surgery (18.5%) than with open surgery (45.5%; p = 0.021). Multivariate analysis revealed open surgery (p = 0.026; odds ratio, 3.535; 95% confidence interval, 1.159-10.781) as an independent predictor of postoperative infectious complications. CONCLUSIONS: Laparoscopic colorectal resection for patients over 90 years old is a useful procedure that reduces postoperative infectious complications.

Prognostic value of lymph node distribution after laparoscopic colectomy with Japanese D3 dissection.

PURPOSE: Positive pathologic lymph nodes in colorectal cancer represent an important prognostic indicator. Whether lymph node distribution or the number of metastatic nodes is more strongly associated with survival prediction remains controversial. METHODS: Among 3449 colorectal cancer surgeries performed at Nagasaki University Hospital and five affiliated institutions from April 2016 to March 2022, we investigated 604 patients who underwent laparoscopic radical resection and were diagnosed with pathological stage III cancer. Patients were divided into two groups according to whether they had central vessel metastasis (LND3 group, n=42) or not (LND1/2 group, n=562). After adjusting for background factors using propensity score matching, the LND3 group included 42 patients and the LND1/2 group included 40 patients. Patient background characteristics and prognosis were compared between these two groups. RESULTS: Before matching, frequencies of right-side colon cancer (64.3% vs 38.1%, p=0.001), multivisceral resection (11.9% vs 4.4%, p=0.039), clinical N2 status (40.5% vs 22.6%, p=0.032), and pathological N2 (73.8% vs 22.6%, p<0.001) were all greater, and the number of lymph nodes retrieved was higher (24 vs 19, p=0.042) in the LND3 group. After matching, no differences in any clinical factors were evident between groups. Five-year RFS (44.8% vs 77.1%, p=0.004) and OS (43.1% vs 83.2%, p<0.001) were worse in the LND3 group. Adjuvant chemotherapy improved RFS (adjuvant chemotherapy (+) vs adjuvant chemotherapy (-): 62.1% vs 27.7%, p=0.047) in the LND3 group. CONCLUSION: LND3-positive patients show poorer prognosis than LND1/2 patients and should be treated with an appropriate perioperative treatment strategy.

Risk factors for reoperation within 30 days in laparoscopic colorectal cancer surgery: A Japanese multicenter study.

INTRODUCTION: Thirty-day reoperation rate reflects short-term surgical outcomes following surgery. Laparoscopic surgery for colorectal cancer reportedly has positive effects on postoperative complications. This retrospective study investigated risk factors for 30-day reoperation rate among patients after laparoscopic colorectal cancer surgery using a multicenter database. METHODS: Participants comprised 3037 patients who had undergone laparoscopic resection of colorectal cancer between April 2016 and December 2022 at the Nagasaki University and six affiliated centers, classified into those who had undergone reoperation within 30 days after surgery (RO group; n = 88) and those who had not (NRO group; n = 2949). Clinicopathological characteristics were compared between groups. RESULTS: In the RO group, anastomotic leakage occurred in 57 patients (64.8%), intestinal obstruction in 12 (13.6%), and intraabdominal abscess in 5 (5.7%). Female patients were more frequent, preoperative treatment less frequent, body mass index (BMI) lower, operation time longer, blood loss greater, and hospital stay longer in the RO group (p < .05 each). Multivariate analysis revealed BMI (odds ratio, 0.415; 95% confidence interval, 0.218-0.787; p = .021) and poor performance status (odds ratio, 1.966; 95% confidence interval, 1.106-3.492; p = .021) as independent predictors of reoperation. CONCLUSION: Perioperative measures are warranted for patients with low BMI and poor performance status undergoing laparoscopic colorectal surgery.

Correlations of age with clinicopathological features, perioperative outcomes and the prognosis in patients with colorectal cancer: a Japanese multicenter study.

PURPOSE: Colorectal cancer is not common in patients under 40 years old, and its associations with clinical features and the prognosis remain uncertain. METHODS: Using a multicenter database, we retrospectively reviewed 3015 patients who underwent colorectal surgery between 2016 and 2021. Patients were divided by age into those < 40 years old (young; n = 52), 40-54 years old (middle-aged; n = 254) and > 54 years old (old; n = 2709). We then investigated age-related differences in clinicopathological features, perioperative outcomes and the prognosis. RESULTS: The proportion of young patients increased annually from 0.63% in 2016 to 2.10% in 2021. Female patients were more frequent, the performance status was better, tumors were larger, clinically node-positive and poorly differentiated adenocarcinomas were more frequent, postoperative complications were less frequent, and the hospital stay was shorter in young patients than in older patients. Young age was an independent predictor of a low risk of postoperative complications (odds ratio, 0.204; 95% confidence interval, 0.049-0.849; p = 0.028). With pathologically node-positive status, adjuvant chemotherapy was more frequent in young patients (100%) than in middle-aged (73.7%) or old (51.8%) patients (p < 0.001), and the 3-year relapse-free survival was better in the young group than in others. CONCLUSION: Despite higher rates of advanced tumors in younger patients, adequate adjuvant chemotherapy appears to improve the relapse-free survival.

Incidence of and risk factors for postoperative ileus between right and left laparoscopic colectomy using propensity-score-matched analysis: A retrospective multicenter study.

INSTRUCTION: In colon cancer, the incidence of postoperative ileus is reportedly higher for the right-side than for the left-side colon, but those studies included small numbers of subjects and contained several biases. Furthermore, risk factors for postoperative ileus remain unclear. METHODS: This multicenter study reviewed 1986 patients who underwent laparoscopic colectomy between 2016 and 2021 for right-side (n = 907) and left-side (n = 1079) colon cancer. After propensity score matching, 803 patients in each group were matched. RESULTS: Postoperative ileus occurred in 97 patients. Before matching, the proportion of female patients and median age were higher and frequency of preoperative stent insertion was lower with right colectomy (P < .001 each). After matching, the number of retrieved lymph nodes (17 vs 15, P < .001) and greater rates of undifferentiated adenocarcinoma (10.6% vs 5.1%, P < .001) and postoperative ileus (6.4% vs 3.2%, P = .004) were higher in right colectomy. Multivariate analysis revealed male gender (hazard ratio, 1.798; 95% confidence interval, 1.049-3.082; P = .32) and history of abdominal surgery (hazard ratio, 1.909; 95% confidence interval, 1.073-3.395; P = .027) as independent predictors of postoperative ileus in right-side colon cancer. CONCLUSION: This study revealed a higher risk of postoperative ileus after right colectomy with laparoscopic surgery. Male gender and history of abdominal surgery were risk factors for postoperative ileus after right colectomy.

Usefulness of the endoscopic surgical skill qualification system for laparoscopic colectomy for transverse colon cancer: a Japanese multicenter analysis.

PURPOSE: Laparoscopic colectomy for transverse colon cancer (TCC) can be technically demanding due to the anatomical complexity of the region. In Japan, the Endoscopic Surgical Skill Qualification System (ESSQS) was established to improve the skill of laparoscopic surgeons and further develop surgical teams. We examined the safety and feasibility of laparoscopic colectomy for TCC and evaluated the effects of the Japanese ESSQS in facilitating this approach. METHODS: We retrospectively reviewed 136 patients who underwent laparoscopic colectomy for TCC between April 2016 and December 2021. Patients were divided into an ESSQS-qualified surgeon group (surgery performed by an ESSQS-qualified surgeon, n = 52) and a non ESSQS-qualified surgeon (surgery performed by a non ESSQS-unqualified surgeon, n = 84). Clinicopathological and surgical features were compared between groups. RESULTS: Postoperative complications occurred in 37 patients (27.2%). The proportion of patients who developed postoperative complications was lower in the ESSQS-qualified surgeon group (8.0%) than that in the non ESSQS-qualified surgeon group (34.5%; p < 0.017). Multivariate analysis revealed "Operation by ESSQS-qualified surgeon surgeon" (odds ratio (OR) 0.360, 95% confidence interval (CI) 0.140-0.924; p = 0.033), blood loss (OR 4.146, 95% CI 1.688-10.184; p = 0.002), and clinical N status (OR 4.563, 95% CI 1.814-11.474; p = 0.001) as factors independently associated with postoperative complications. CONCLUSION: The present multicenter study confirmed the feasibility and safety of laparoscopic colectomy for TCC and revealed that ESSQS-qualified surgeon achieved better surgical outcomes.

Efficacy of left colic artery preservation with D3 lymph node dissection in laparoscopic surgery for advanced sigmoid and rectal cancer.

PURPOSE: For advanced left colon cancer, lymph node dissection at the root of the inferior mesenteric artery is recommended. Whether the left colic artery (LCA) should be preserved or resected remains contentious. METHODS: The 367 patients who underwent laparoscopic sigmoidectomy or anterior resection and who were pathologically node-positive were reviewed. Patients were divided into LCA-preserving group (LCA-P, n = 60) and LCA-non-preserving group (LCA-NP, n = 307). Propensity score matching was applied to minimize selection bias and 59 patients were matched. RESULTS: Before matching, the rates of poor performance status and cardiovascular disease were higher in the LCA-P group (p < 0.001). After matching, operation time was longer (276 vs. 240 min, p = 0.001), the frequency of splenic flexure mobilization (62.7% vs. 33.9%, p = 0.003) and lymphovascular invasion (84.7% vs. 55.9%, p = 0.001) was higher in the LCA-P group. Severe postoperative complications (CD ≥ 3) occurred only in the LCA-NP group (0% vs. 8.4%, p = 0.028). The median follow-up period was 38.5 months (range 2.0-70.0 months). The 5-year RFS rates (67.8% vs. 66.0%, p = 0.871) and OS rates (80.4% vs. 74.9%, p = 0.308) were comparable between the groups. CONCLUSIONS: Laparoscopic LCA-sparing surgery for left-sided colorectal cancer reduces the risk of severe complications and offers a favorable long-term prognosis.

Effect of adjuvant chemotherapy after curative resection of colorectal cancer peritoneal metastasis.

PURPOSE: Several guidelines have recommended surgical resection for localized peritoneal metastases, but the prognosis remains poor. In addition, the efficacy of adjuvant chemotherapy (AC) after curative resection is under debate. The present study compared long-term outcomes between curative and non-curative resection and evaluated the effects of AC after curative resection. METHODS: Using a multicenter database, we retrospectively reviewed 123 colorectal cancer patients with peritoneal metastases between April 2016 and December 2021. Of these patients, 49 underwent curative resection, and 74 underwent non-curative resection. RESULTS: The frequency of broad metastases was lower in the curative resection group (8.2%) than in the non-curative resection group (43.2%, p < 0.001). Among all patients, 5-year overall survival rate was higher in the curative resection group (43.0%) than in the non-curative resection group (7.3%, p = 0.004). Among patients who underwent curative resection, 5-year overall survival rate was significantly higher in the AC group (48.2%) than in the non-AC group (38.1%, p = 0.037). Multivariate analysis of all patients revealed pathological N status and non-curative resection as independent predictors of overall survival. In patients who underwent curative resection, advanced age was an independent predictor of relapse-free survival, and AC was an independent predictor of overall survival. CONCLUSION: This multicenter study of colorectal cancer patients with peritoneal metastases revealed that prognosis was more favorable for curable cases than for non-curable cases. Prognosis was more favorable in the AC group than in the non-AC group after curative resection.

Relationship between perfusion index and central temperature before and after induction of anesthesia in laparoscopic gastrointestinal surgery: A prospective cohort study.

The perfusion index (PI) cutoff value before anesthesia induction and the ratio of PI variation after anesthesia induction remain unclear. This study aimed to clarify the relationship between PI and central temperature during anesthesia induction, and the potential of PI in individualized and effective control of redistribution hypothermia. This prospective observational single center study analyzed 100 gastrointestinal surgeries performed under general anesthesia from August 2021 to February 2022. The PI was measured as peripheral perfusion, and the relationship between central and peripheral temperature values was investigated. Receiver operating characteristic curve analysis was performed to identify baseline PI before anesthesia, which predicts a decrease in central temperature 30 minutes after anesthesia induction, and the rate of change in PI that predicts the decrease in central temperature 60 minutes after anesthesia induction. In cases with a central temperature decrease of ≥ 0.6°C after 30 minutes, the area under the curve was 0.744, Youden index was 0.456, and the cutoff value of baseline PI was 2.30. In cases with a central temperature decrease of ≥ 0.6°C after 60 minutes, the area under curve was 0.857, Youden index was 0.693, and the cutoff value of the PI ratio of variation after 30 minutes of anesthesia induction was 1.58. If the baseline PI is ≤ 2.30 and the PI 30 minutes after anesthesia induction is at least 1.58-fold the PI ratio of variation, there is a high probability of a central temperature decrease of at least 0.6°C within 30 minutes after 2 time points.

Mid-term outcomes of laparoscopic vs open colectomy for pathological T4 and/or N2 colon cancer patients: Multicenter study using propensity score matched analysis.

OBJECTIVES: We aimed to assess mid-term outcomes after laparoscopic surgery (LAP) vs open surgery (OP) for pathological T4 (pT4) and/or N2 (pN2) colon cancer. METHODS: We retrospectively reviewed 255 primary tumor resections for pT4 and/or pN2 colon cancer performed from 2015 to 2020 at six hospitals, divided into LAP (n = 204) and OP groups (n = 51). After propensity score matching to minimize selection bias, 47 matched patients per group were assessed. RESULTS: Before matching, the rate of males (53.9% vs. 37.3%, P = .042), left sided colon cancer (53.9% vs 37.3%, P = .042), D3 lymph node dissection (90.7% vs 68.6%, P < .001) and body mass index (kg/m2 ) (22.3 vs 21.8, P = .039) were significantly greater in the LAP group. The rate of pT4b (7.8% vs 40.4%, P < .001) was lower and pN2 was higher (57.4% vs 37.3%, P = .012) in the LAP group. After matching, preoperative characteristics and pathologic status were equivalent between the groups. The LAP and OP groups showed comparable overall survival (OS) (2-year OS, 84.5% vs 76.8%, P = .055) and recurrence-free survival (RFS) (2-year RFS, 73.9% vs 52.8%, P = .359). In the patients with pT4, OS (2-year OS, 79.4% vs 75.7%, P = .359) and RFS (2-year RFS, 71.3% vs 58.7%) were comparable. In the patients with pN2, OS (2-year OS, 83.4% vs 76.3%) and RFS (2-year RFS, 69.6% vs 36.2%) were also comparable. CONCLUSIONS: LAP for pT4 and/or pN2 colon cancer showed comparable mid-term outcomes compared with OP. LAP was an acceptable surgical approach in this cohort.

Effect of intraoperative operating table rotation on lower limb perfusion index in patients in the lithotomy position.

We focused on "returning to the horizontal position," one of the measures for preventing well leg compartment syndrome implemented at our hospital, and aimed to clarify the effect of intraoperative positional changes by operating table rotation on blood perfusion in the lower extremities during lithotomy in patients under general anesthesia. This prospective observational study examined 64 patients scheduled to undergo general anesthesia in the lithotomy position from March 2021 to May 2022. The primary endpoint was the perfusion index (PI) of the lower limb before and after operating table rotation. The baseline lower limb PI before the operating table rotation was 2.376 (1.591), and the lower limb PI after the change from Trendelenburg to the horizontal position was as follows: immediately after, 2.123 (1.405); 5 minutes, 1.894 (1.138); 10 minutes, 1.915 (1.167); and 15 minutes, 1.993 (1.218). Compared with the baseline, no significant difference was noted in the change in the lower limb PI due to the Trendelenburg to horizontal positional change. The baseline lower leg pressure before the operating table rotation was 51.4 (13.4) mm Hg, and the lower leg pressure after the change from the Trendelenburg to the horizontal position was as follows: immediately after, 36.6 (10.3) mm Hg; 5 minutes, 36.5 (10.2) mm Hg; 10 minutes, 36.4 (10.0) mm Hg; and 15 minutes, 36.5 (10.2) mm Hg. Compared with the baseline, the change in lower leg pressure due to the Trendelenburg to horizontal positional change showed a significant decrease immediately afterward (P < .001). After operating table rotation from the Trendelenburg to the horizontal position, the lower limb PI did not change significantly after 15 min. However, lower leg pressure showed a significant decrease immediately after returning to the horizontal position. This result provides evidence for operating table rotation as a preventive measure for well leg compartment syndrome.

Application of laparoscopic distal pancreatectomy for normal anatomy after hiatal hernia repair: A case report.

We describe a case of pancreatic tumor associated with a giant type IV hiatal hernia that had prolapsed into the posterior mediastinum. Hiatal hernia repair should be performed first because it enables laparoscopic distal pancreatectomy to be performed in the normal anatomical position.

Hepatocellular carcinoma with situs inversus totalis treated by caudate lobectomy: A case report.

INTRODUCTION: Situs inversus totalis (SIT) is a congenital anatomical variant in which organs and vasculature are positioned in a mirror-image relationship to the normal condition. Therefore, the surgical procedures need to be carefully planned with these factors in mind. CASE PRESENTATION: A 57-year-old man with SIT was diagnosed with a hepatocellular carcinoma (HCC) and was planned for caudate lobectomy. As preoperative preparation, 3D reconstructed images were created based on the contrast-enhanced CT images, and careful simulations were performed on the vascular anomalies and location of the tumor. There was a replaced left hepatic artery forming a common trunk with a left gastric artery. In addition, using media player software, a previous caudate lobectomy video was played in right and left inverted mode to simulate the abdominal surgical field image in SIT. The operative time was 285 min, and the blood loss was 440 ml. The preoperative careful simulation allowed us to proceed with the surgery without significant discomfort. CONCLUSION: Even in the case of hepatocellular carcinoma with SIT, hepatectomy for hepatocellular carcinoma can be safely performed by careful preoperative simulations.

Effect of oxaliplatin in elderly colon cancer patients with pathological T4 and/or N2 disease: a multicenter, propensity score-matched analysis.

PURPOSE: Although adjuvant chemotherapy (AC) using fluoro-pyrimidine and oxaliplatin (FU + oxaliplatin) is recommended after curative resection for locally advanced colon cancer patients, several randomized controlled trials have shown no additional effect of oxaliplatin in patients aged ≥ 70 years. Here, we examined the effectiveness of FU + oxaliplatin on the long-term outcome of old patients with a high risk of recurrence. METHODS: This multicenter, retrospective study included 346 colon cancer patients diagnosed with pathological T4 and/or N2 disease from 2016 to 2020. They were divided into an old group (≥ 70 years, n = 197) and a young group (< 70 years, n = 167). Propensity score matching was used to minimize selection bias, and 126 patients per group were matched. RESULTS: Before matching, the rates of poor performance status (p < 0.001) and the presence of comorbidities (76.1% vs. 47.9%, p < 0.001) were higher in the old group. Although all baseline factors were similar between groups, after matching, the AC rate was lower in the old group (45.2% vs. 65.1%, p = 0.002). In the old group, relapse-free (82.2% vs. 55.6% and 69.6%, p < 0.05) and overall survival (83.1% vs. 80.0% and 44.4%, p < 0.05) rates were significantly higher in the AC patients with FU + oxaliplatin than in the AC patients with only FU and the non-AC patients. CONCLUSION: The selected old colon cancer patients with a high risk of recurrence gained an additional benefit with respect to prognosis from FU + oxaliplatin as AC.

A case of retroperitoneal abscess caused by infection of urachal remnant.

Infection of urachal remnant may cause recurrent abscesses. In the current case report, we describe a urachal remnant infection leading to a retroperitoneal abscess, which is an extremely rare condition. In such cases, the recommended treatment is urachal remnant resection.