小林 陽介

PURPOSE: To develop an educational program that enables young surgeons to safely perform laparoscopic transabdominal preperitoneal repair (TAPP). METHODS: This retrospective study comprised 365 patients who underwent elective TAPP performed by surgical residents (SRs; n = 145 patients) and board-certified surgeons (BCSs; n = 220 patients) from January 2018 to December 2023. An educational program for SRs has been underway since April 2021 to facilitate efficient learning and ensure the safe performance of TAPP. This program comprises four steps and highlights the two points mentioned, including understanding technical principles and acquiring fundamental skills. The surgical outcomes of laparoscopic TAPP performed by SRs and BCSs were compared retrospectively. RESULTS: A total of 43 operators (16 SRs and 27 BCSs) performed the laparoscopic TAPP. The SRs demonstrated longer operative times (median 126 vs. 98 min; p < 0.01). No significant differences in the rates of seroma (7.6% vs. 5.5%), grade IIIa or higher Clavien-Dindo complications (early: 0.7 vs. 0.9%; late: 0.7% vs. 0%), and recurrence at 1 year after surgery (1.4% vs. 0.5%) were observed between the SR and BCSs groups. Following the implementation of the educational program in April 2021, laparoscopic TAPP procedures performed by SRs were associated with significantly shorter operation times compared to those conducted before the program was introduced. CONCLUSIONS: SRs who received presurgical education improved the operative time in laparoscopic TAPP, although with intraoperative guidance from Endoscopic Surgical Skill Qualification System-qualified surgeons.

BACKGROUND: Robotic surgery for rectal cancer has grown popular in recent years and has primarily used the da Vinci Surgical System (Intuitive Surgical, CA, USA; da Vinci). In 2020, Japan introduced the hinotori™ Surgical Robot System (Medicaroid, Kobe, Japan; hinotori). We report our initial surgical experiences with robotic surgery using hinotori for rectal cancer and its feasibility and safety comparing with da Vinci. METHODS: A single-institution retrospective study was conducted. Between November 2022 and November 2023, 38 and 96 patients with rectal cancer underwent robotic surgery using hinotori and da Vinci, respectively. The primary endpoint was the incidence of postoperative complications of the Clavien-Dindo classification (CD) grade ≥ II within postoperative 30 days. Secondary endpoints included surgical and console time, blood loss, conversion to other approaches, number of dissected lymph nodes, and postoperative hospital stay. A propensity score matching (PSM) analysis was used to adjust for imbalance in baseline characteristics. RESULTS: After PSM, a total of 76 patients (hinotori: 38, da Vinci: 38) were included. Compared to the da Vinci group, the hinotori group showed a similar postoperative complication rate of CD ≥ II (15.8% vs. 18.4%), comparable operative time (280.5 vs. 258 min), comparable console time (166 vs. 156 min), and less blood loss (9 vs. 17.5 mL, p = 0.025). There was no conversion in either group. The number of dissected nodes and postoperative stay were similar between the two groups. CONCLUSION: Our findings support that robotic surgery for rectal cancer using hinotori is as safe as surgery performed using the da Vinci system.

BACKGROUND AND PURPOSE: Accurate recurrence risk evaluation in patients with stage II and III colorectal cancer (CRC) remains difficult. Traditional histopathological methods frequently fall short in predicting outcomes after adjuvant chemotherapy. This study aims to evaluate the use of comprehensive genomic profiling combined with machine learning for prognostic risk stratification in patients with CRC. METHODS: A machine learning model was developed using a training cohort of 52 patients with stage II/III CRC who underwent curative surgery at Fujita Health University Hospital. Genomic DNA was isolated from formalin-fixed, paraffin-embedded tissue sections and analyzed with a 160 cancer-related gene panel. The random forest algorithm was used to determine key genes affecting recurrence-free survival. The model was validated by developing a risk score with internal and external cohorts, including 44 patients from Keio University Hospital. RESULTS: Six key genes (KRAS, KIT, SMAD4, ARID2, NF1, and FBXW7) were determined as significant prognostic risk predictors. A risk score system integrating these genes with clinicopathological factors effectively stratified patients in both internal (p < 0.001) and external cohorts (p = 0.017). CONCLUSIONS: This study reveals that machine learning, combined with comprehensive genomic profiling, significantly improves prognostic risk stratification in patients with stage II/III CRC after adjuvant chemotherapy. This approach provides a promising tool for individualized treatment strategies, warranting further validation with larger cohorts.

Colorectal cancer (CRC) is well characterized in terms of genetic mutations and the mechanisms by which they contribute to carcinogenesis. Mutations in APC, TP53, and KRAS are common in CRC, indicating key roles for these genes in tumor development and progression. However, for certain tumors with low frequencies of these mutations that are defined by tumor location and molecular phenotypes, a carcinogenic mechanism dependent on BRAF mutations has been proposed. We here analyzed targeted sequence data linked to clinical information for CRC, focusing on tumors with a high tumor mutation burden (TMB) in order to identify the characteristics of associated mutations, their relations to clinical features, and the mechanisms of carcinogenesis in tumors lacking the major driver oncogenes. Analysis of overall mutation frequencies confirmed that APC, TP53, and KRAS mutations were the most prevalent in our cohort. Compared with other tumors, TMB-high tumors were more frequent on the right side of the colon, had lower KRAS and higher BRAF mutation frequencies as well as a higher microsatellite instability (MSI) score, and showed a greater contribution of a mutational signature associated with MSI. Ranking of variant allele frequencies to identify genes that play a role early in carcinogenesis suggested that mutations in genes related to the DNA damage response (such as ATM and POLE) and to MSI (such as MSH2 and MSH6) may precede BRAF mutations associated with activation of the serrated pathway in TMB-high tumors. Our results thus indicate that TMB-high tumors suggest that mutations of genes related to mismatch repair and the DNA damage response may contribute to activation of the serrated pathway in CRC.

BACKGROUND: In the field of abdominal surgery, including colorectal cancer surgery, robotic surgery has become widespread, and the introduction of new robotic platforms is increasing. As a result, the incidence of subcutaneous emphysema (SE) as a postoperative complication has increased; however, the causes, grade, and perioperative course of SE have not been definitively examined. Therefore, we aimed to evaluate potential risk factors of SE after robotic colorectal cancer surgery. METHODS: Between November 2022 and March 2024, 244 consecutive patients who underwent robotic colorectal cancer surgery using the da Vinci Xi (n = 190) or the hinotori™ platform (n = 54) were retrospectively analyzed. Risk factors associated with postoperative SE were assessed by multivariate analysis using logistic regression models. Moreover, the grade of SE and its perioperative course were investigated based on the two robotic platforms. RESULTS: Postoperative SE was observed in 95 patients (38.9%). Nine patients (3.7%) had severe SE. The risk factors for SE were female sex, older age (≥ 80 years), and maximum intraabdominal pressure (max IAP) with CO2 insufflation > 10 mmHg (odds ratio [95% confidence interval]: 1.981 [1.105-3.552], p = 0.022; 2.765 [1.310-5.835], p = 0.008; and 13.249 [1.227-143.020], p = 0.033, respectively). Additionally, the incidence of SE when using the hinotori™ platform was significantly lower than when using the da Vinci Xi platform (0.302 [0.135-0.667], p = 0.004). CONCLUSIONS: Max IAP with CO2 > 10 mmHg was associated with SE during robotic colorectal cancer surgery. Compared with the use of da Vinci Xi, the use of hinotori™ was associated with fewer incidences of postoperative SE, especially in females and older patients (≥ 80 years).

Pelvic arteriovenous malformation (AVM) is a rare vascular condition with diverse clinical manifestations. Treatment-related decision-making is difficult for concurrent AVMs and colon cancer. Interventional radiology is effective for colon cancer patients with pelvic AVM. Herein, a 77-year-old man presented with fatigue. Computed tomography revealed thickening of the sigmoid colon wall without lymph node swelling or distant metastasis, confirming irregularly dilated pelvic blood vessels. Preoperative transcatheter embolization of the AVM was initially performed. Then, laparoscopic sigmoidectomy was performed without complications following confirmation of AVM shrinkage via computed tomography. The patient was discharged without complications. Thus, preoperative pelvic AVM embolization in patients with sigmoid colon cancer may facilitate safe minimally invasive surgery.

Subtotal colectomy is often performed on patients with synchronous colorectal cancer. However, compared with colorectal anastomosis, ileorectal anastomosis with subtotal colectomy is more likely to result in bowel dysfunction. The Deloyers procedure is useful in preserving bowel function in a patient with synchronous colorectal cancer. An 87-year-old man presented with bloody stool. Colonoscopy showed masses in the cecum, transverse colon, rectosigmoid, and rectum above the peritoneal reflection. Computed tomography scan revealed no evidence of regional lymph node swelling and distant metastasis. Therefore, robot-assisted low anterior resection, laparoscopic extended left hemicolectomy, laparoscopic cecal resection, and diverting ileostomy were performed. The patient was discharged from the hospital without complications. There was no recurrence, and the patient did not have complaints such as urgency, fecal incontinence, and excretory dysfunction. Hence, minimally invasive coloproctectomy using the Deloyers procedure can be safe and useful in preserving postoperative bowel function in elderly patients.

Undergoing another surgery after a previous abdominal procedure can sometimes result in significant abdominal adhesions. We present a case of robot-assisted low anterior resection in a patient with rectal cancer who had a urinary reservoir. A 65-year-old male patient underwent robot-assisted total bladder resection and creation of a urinary reservoir for bladder cancer in 2013. He presented with melena. Thus, the findings revealed advanced low rectal cancer. The robot-assisted low anterior resection was performed in 2022. Extensive adhesions were observed in the pelvic space. The indocyanine green function was appropriately used, and the robotic surgery was completed without injury to the urinary reservoir or major complications. The surgical time was 510 min, and the blood loss volume was 15 mL. The patient had been recurrence free for 12 months following the surgery. Robot-assisted surgery can be beneficial for patients with rectal cancer with significant pelvic adhesions.

INTRODUCTION: Post-contrast acute kidney injury (PC-AKI) is a major complication of contrast media usage; risks for PC-AKI are generally evaluated before computed tomography (CT) with contrast at the emergency department (ED). Although persistent hypotension (systolic blood pressure [sBP] <80 mm Hg for 1 h) is associated with increased PC-AKI incidence, it remains unclear whether transient hypotension that is haemodynamically stabilized before CT is a risk of PC-AKI. We hypothesized that hypotension on ED arrival would be associated with higher PC-AKI incidence even if CT with contrast was performed after patients are appropriately resuscitated. METHODS: This multicentre retrospective observational study was conducted at three tertiary care centres during 2013-2014. We identified 280 patients who underwent CT with contrast at the ED. Patients were classified into two groups based on sBP on arrival (<80 vs. ≥80 mm Hg); hypotension was considered as transient because CT with contrast has always been performed after patients were stabilized at participating hospitals. PC-AKI incidence was compared between the groups; inverse probability weighting (IPW) was conducted to adjust background characteristics. RESULTS: Eighteen patients were excluded due to chronic haemodialysis, cardiac arrest on arrival, or death within 72 h; 262 were eligible for this study. PC-AKI incidence was higher in the transient hypotension group than the normotension group {7/27 (28.6%) vs. 24/235 (10.2%), odds ratio (OR) 3.08 (95% confidence interval [CI] 1.18-8.03), p = 0.026}, which was confirmed by IPW (OR 3.25 [95% CI 1.99-5.29], p < 0.001). CONCLUSION: Transient hypotension at the ED was associated with PC-AKI development.

A 70-year-old Japanese woman who was treated for interstitial pneumonia (IP) with steroid therapy developed cholecystitis. A serial computed-tomography (CT) imaging showed irregular thickness of the fundus wall of the gallbladder and two rapidly enlarged lymph nodes (LNs): number (no.) 12 and no. 8a. Positron-emission tomography-computed tomography (PET-CT) scan showed an abnormal uptake at the site of the gallbladder tumor and those LNs. We subsequently performed open radical cholecystectomy and LN dissection of the no. 12 and 8a LNs, following complete remission of IP. The histology showed gallbladder adenocarcinoma, with a single focus of neuroendocrine carcinoma (NEC) component of less than 30%; Ki-67 index > 80%, synaptophysin (Syn) (+), chromogranin A (CgA) (+), and clusters of differentiation (CD) 56 (+) (T2bN1M0, Stage IIIB). LN no. 8a was diffusely metastatic with NEC components. LN no. 12c, which was adjacent to the cystic duct, revealed necrosis without apparent tumor cells, but was highly suspicious for tumor necrosis. The final diagnosis was adenocarcinoma of the gallbladder with focal NEC (< 30%), which did not meet the criteria for mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN). Postoperatively, she completed 4 cycles of adjuvant chemotherapy for NEC (Cisplatin plus Etoposide), and no recurrence was observed after 12 months.

Massive hemothorax due to multiple rib fractures and intercostal artery (ICA) injuries is one of the most lethal forms of chest trauma. Urgent thoracotomy is required; however, suturing is sometimes difficult owing to the limited operative field in the thoracic cavity and because the transected ICA retracts between the surrounding intercostal muscles. We present a patient with refractory ICA bleeding induced by severe blunt thoracic injury successfully treated with extensive rib resection followed by thoracic wall reconstruction using GORE® DUALMESH® and titanium plates. A 66-year-old woman attempted suicide by diving into the path of a train. She incurred massive left hemothorax associated with multiple rib fractures and severe trauma to her extremities; both upper limbs and left leg at the thigh were nearly disconnected. Initially, she underwent urgent left anterolateral thoracotomy followed by partial lung resection and suture hemostasis of the thoracic wall. Subsequently, interventional radiology was performed for the ICA bleeding, and her extremities except her right leg were amputated. However, because hemothorax persisted, and because of the comminuted fractures, we removed the fifth to eighth ribs, and the ICA vascular sheath was ligated. Resecting multiple ribs caused deformities and lung herniations, although hemostasis was achieved. On the third postoperative day, thoracic reconstruction using Gore-Tex® Dual Mesh and titanium plates was performed. Although a small empyema occurred, it was controlled with antibiotics and drainage. Paradoxical respiration and atelectasis did not occur, and the patient was moved to the hospital for continued care in a lucid state.

OBJECTIVES: Surgery for colonic perforation has high morbidity and mortality rates. Predicting complications preoperatively would help improve short-term outcomes; however, no predictive risk stratification model exists to date. Therefore, the current study aimed to determine risk factors for complications after colonic perforation surgery and use machine learning to construct a predictive model. METHODS: This retrospective study included 51 patients who underwent emergency surgery for colorectal perforation. We investigated the connection between overall complications and several preoperative indicators, such as lactate and the Glasgow Prognostic Score. Moreover, we used the classification and regression tree (CART), a machine-learning method, to establish an optimal prediction model for complications. RESULTS: Overall complications occurred in 32 patients (62.7%). Multivariate logistic regression analysis identified high lactate levels [odds ratio (OR), 1.86; 95% confidence interval (CI), 1.07-3.22; p = 0.027] and hypoalbuminemia (OR, 2.56; 95% CI, 1.06-6.25; p = 0.036) as predictors of overall complications. According to the CART analysis, the albumin level was the most important parameter, followed by the lactate level. This prediction model had an area under the curve (AUC) of 0.830. CONCLUSIONS: Our results determined that both preoperative albumin and lactate levels were valuable predictors of postoperative complications among patients who underwent colonic perforation surgery. The CART analysis determined optimal cutoff levels with high AUC values to predict complications, making both indicators clinically easier to use for decision making.

Oxidative stress plays a key role in the pathophysiology of post-cardiac arrest syndrome. Molecular hydrogen reduces oxidative stress and exerts anti-inflammatory effects in an animal model of cardiac arrest. However, its effect on human post-cardiac arrest syndrome is unclear. We consecutively enrolled five comatose post-cardiac arrest patients (three males; mean age, 65 ± 15 years; four cardiogenic, one septic cardiac arrest) and evaluated temporal changes in oxidative stress markers and cytokines with inhaled hydrogen. All patients were treated with target temperature management. Hydrogen gas inhalation (2% hydrogen with titrated oxygen) was initiated upon admission for 18 h. Blood hydrogen concentrations, plasma and urine oxidative stress markers (derivatives of reactive oxygen metabolites, biological antioxidant potential, 8-hydroxy-2'-deoxyguanosine, N ɛ-hexanoyl-lysine, lipid hydroperoxide), and cytokines (interleukin-6 and tumor necrosis factor-α) were measured before and 3, 9, 18, and 24 h after hydrogen gas inhalation. Arterial hydrogen concentration was measurable and it was equilibrated with inhaled hydrogen. Oxidative stress was reduced and cytokine levels were unchanged in cardiogenic patients, whereas oxidative stress was unchanged and cytokine levels were diminished in the septic patient. The effect of inhaled hydrogen on oxidative stress and cytokines in comatose post-cardiac arrest patients remains indefinite because of methodological weaknesses.

The prevalence of lung cancer in idiopathic pulmonary fibrosis (IPF) patients ranges from 9.8 to 38%. Nintedanib, a small molecule receptor tyrosine kinase inhibitor (TKI) of platelet-derived growth factor receptor (PDGFR), fibroblast growth factor receptor (FGFR), and vascular endothelial growth factor receptor (VEGFR), has been approved for IPF after phase III INPULSIS trials in 2014. Ramucirumab, a monoclonal antibody for VEGFR-2, combined with docetaxcel, has been approved for advanced non-small cell lung cancer (NSCLC) after the phase III REVEL trail in 2014. Physicians will have more IPF patients being treated with nintedanib, who subsequently develop NSCLC, and therefore will likely be treated with ramucirumab plus docetaxel. We report the first case of 70-year-old man taking nintedanib for his IPF and treated with ramucirumab plus docetaxel as a seventh-line therapy for his pulmonary adenocarcinoma. On day 15 of his chemotherapy treatment cycle 2, after taking nintedanib for nine days, he developed gastric perforation.

BACKGROUND: Hydrogen gas inhalation (HI) ameliorates cerebral and cardiac dysfunction in animal models of post-cardiac arrest syndrome (PCAS). HI for human patients with PCAS has never been studied. METHODS AND RESULTS: Between January 2014 and January 2015, 21 of 107 patients with out-of-hospital cardiac arrest achieved spontaneous return of circulation. After excluding 16 patients with specific criteria, 5 patients underwent HI together with target temperature management (TTM). No undesirable effects attributable to HI were observed and 4 patients survived 90 days with a favorable neurological outcome. CONCLUSIONS: HI in combination with TTM is a feasible therapy for patients with PCAS. (Circ J 2016; 80: 1870-1873).