渡部 文昭

BACKGROUND: While seasonality of hospital-acquired infections, including incisional SSI after orthopaedic surgery, is recognized, the seasonality of incisional SSI after general and gastroenterological surgeries remains unclear. STUDY DESIGN: This retrospective single-institute observational study analysed the seasonality and risk factors of incisional SSI after general and gastroenterological surgeries using univariate and multivariable analyses. The evaluated variables included age, sex, surgical approach, surgical urgency, operation time, wound classification, and the American Society of Anesthesiologists physical status (ASA-PS). RESULTS: 8,436 patients were enrolled. General surgeries (n=2,241) showed a pronounced SSI incidence in summer (3.9%; odds ratio [OR] 1.87; 95% confidence interval [CI] 1.05-3.27; p=0.025) compared to other seasons (2.1%). Conversely, gastroenterological surgeries (n=6,195) showed a higher incidence in winter (8.3%; OR 1.38; 95% CI 1.10-1.73; p=0.005) than in other seasons (6.1%). Summer for general surgery (OR 1.90; 95% CI 1.12-3.24; p=0.018) and winter for gastroenterological surgery (OR 1.46; 95% CI 1.17-1.82; p=0.001) emerged as independent risk factors for incisional SSI. Open surgery (OR, 2.72; 95% CI 1.73-4.29, p<0.001) and an ASA-PS score ≥3 (OR, 1.64; 95% CI 1.08-2.50, p=0.021) were independent risk factors for incisional SSI in patients undergoing gastroenterological surgery during winter. CONCLUSION: Seasonality exists in the incisional SSI incidence following general and gastroenterological surgeries. Recognizing these trends may help enhance preventive strategies, highlighting the elevated risk in summer for general surgery and in winter for gastroenterological surgery.

PURPOSE: Mesopancreas resection is a crucial but difficult procedure when performing pancreaticoduodenectomy. This study evaluated the influence of mesopancreas thickness on surgical outcomes in patients undergoing pancreaticoduodenectomy. METHODS: We measured the thickness of the fat tissue on the right side of the superior mesenteric artery from the dorsal margin of the confluence of the superior mesenteric vein and portal vein to the ventral margin of the left renal vein on preoperative contrast-enhanced computed tomography and defined it as the mesopancreas thickness. We evaluated the correlation between mesopancreas thickness and intraoperative and postoperative variables in 357 patients who underwent pancreaticoduodenectomy. RESULTS: Multivariate analysis revealed that a thick mesopancreas was significantly associated with a long operative time (β = 10.361; 95% confidence interval, 0.370-20.353, p = 0.042), high estimated blood loss (β = 36.038; 95% confidence interval, -27.192-99.268, p = 0.013), and a low number of resected lymph nodes (β = -1.551; 95% confidence interval, -2.662--0.439, p = 0.006). This analysis further revealed that thick mesopancreas was a significant risk factor for overall morbidity (odds ratio 2.170; 95% confidence interval 1.340-3.520, p = 0.002), major morbidity (odds ratio 2.430; 95% confidence interval 1.360-4.340, p = 0.003), and a longer hospital stay (β = 2.386; 95% confidence interval 0.299-4.474, p = 0.025). CONCLUSION: A thick mesopancreas could predict a longer operation time, higher estimated blood loss, fewer resected lymph nodes, more frequent overall and major morbidities, and a longer hospital stay in patients who underwent pancreaticoduodenectomy more precisely than the body mass index.

BACKGROUND: The recent guidelines from the European and American Hernia Societies recommend a continuous small-bite suturing technique with slowly absorbable sutures for fascial closure of midline abdominal wall incisions to reduce the incidence of wound complications, especially for incisional hernia. However, this is based on low-certainty evidence. We could not find any recommendations for skin closure. The wound closure technique is an important determinant of the risk of wound complications, and a comprehensive approach to prevent wound complications should be developed. METHODS: We propose a single-institute, prospective, randomized, blinded-endpoint trial to assess the superiority of the combination of continuous suturing of the fascia without peritoneal closure and continuous suturing of the subcuticular tissue (study group) over that of interrupted suturing of the fascia together with the peritoneum and interrupted suturing of the subcuticular tissue (control group) for reducing the incidence of midline abdominal wall incision wound complications after elective gastroenterological surgery with a clean-contaminated wound. Permuted-block randomization with an allocation ratio of 1:1 and blocking will be used. We hypothesize that the study group will show a 50% reduction in the incidence of wound complications. The target number of cases is set at 284. The primary outcome is the incidence of wound complications, including incisional surgical site infection, hemorrhage, seroma, wound dehiscence within 30 days after surgery, and incisional hernia at approximately 1 year after surgery. DISCUSSION: This trial will provide initial evidence on the ideal combination of fascial and skin closure for midline abdominal wall incision to reduce the incidence of overall postoperative wound complications after gastroenterological surgery with a clean-contaminated wound. This trial is expected to generate high-quality evidence that supports the current guidelines for the closure of abdominal wall incisions from the European and American Hernia Societies and to contribute to their next updates. TRIAL REGISTRATION: UMIN-CTR UMIN000048442. Registered on 1 August 2022. https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000055205.

Nivolumab monotherapy is a standard treatment of metastatic gastric cancer, and this type of cancer involves vascular endothelial growth factor (VEGF) signaling in the tumor immunological environment. The subgroup analysis of the ATTRACTION-2 trial revealed that prior treatment with ramucirumab (RAM), a VEGF inhibitor, affected the therapeutic effect of nivolumab. The present retrospective study aimed to review patients with metastatic gastric cancer who were treated with paclitaxel (PTX) and RAM followed by nivolumab. A total of 29 patients with metastatic gastric cancer were treated with PTX + RAM as second-line treatment, followed by nivolumab monotherapy as third-line treatment. The therapeutic efficacy of nivolumab was compared in 13 patients with progression-free survival (PFS) of <5 months and 16 patients with PFS ≥5 months after PTX + RAM therapy. The present study included 22 male and seven female patients, with a median age of 68 years (range, 45-82 years). Human epidermal growth factor receptor 2 positivity was observed in six patients. The disease control rate was 62.1%. The PFS and overall survival (OS) were 4.4 and 11.9 months, respectively. Patients with PFS ≥5 months after PTX + RAM therapy showed better outcome in both PFS (5.3 months vs. 2.8 months, P=0.039) and OS (6.9 months vs. 15.2 months, P=0.066) after nivolumab treatment than patients with PFS of <5 months after PTX + RAM therapy. However, no significant relationship was observed between the outcome of first-line treatment and nivolumab. The therapeutic effect of nivolumab was associated with prior PTX + RAM treatment in advanced gastric cancer.

PURPOSE: Midline abdominal incisions (MAIs) are widely used in both open and minimally invasive surgery. Incisional hernia (IH) accounts for most long-term postoperative wound complications. This study explored the risk factors for IH due to MAI in patients with clean-contaminated wounds after elective gastroenterological surgery. METHODS: The present study targeted patients enrolled in 2 randomized controlled trials to evaluate the efficacy of intraoperative interventions for incisional SSI prevention after gastroenterological surgery for clean-contaminated wounds. The patients were reassessed, and pre- and intraoperative variables and postoperative outcomes were collected. IH was defined as any abdominal wall gap, regardless of bulge, in the area of a postoperative scar that was perceptible or palpable on clinical examination or computed tomography according to the European Hernia Society guidelines. The risk factors for IH were identified using univariate and multivariate analyses. RESULTS: The study population included 1,281 patients, of whom 273 (21.3%) developed IH. Seventy-four (5.8%) patients developed incisional SSI. Multivariate logistic regression analysis revealed that female sex (odds ratio [OR], 1.39; 95% confidence interval [CI] 1.03-1.86, p = 0.031), high preoperative body mass index (OR, 1.81; 95% CI 1.19-2.77, p = 0.006), incisional SSI (OR, 2.29; 95% CI 1.34-3.93, p = 0.003), and postoperative body weight increase (OR, 1.49; 95% CI 1.09-2.04, p = 0.012) were independent risk factors for IH due to MAI in patients who underwent elective gastroenterological surgery. CONCLUSION: We identified postoperative body weight increase at one year as a novel risk factor for IH in patients with MAI after elective gastroenterological surgery.