Explainable artificial intelligence prediction-based model in laparoscopic liver surgery for segments 7 and 8: an international multicenter study.

BACKGROUND: Artificial intelligence (AI) is becoming more useful as a decision-making and outcomes predictor tool. We have developed AI models to predict surgical complexity and the postoperative course in laparoscopic liver surgery for segments 7 and 8. METHODS: We included patients with lesions located in segments 7 and 8 operated by minimally invasive liver surgery from an international multi-institutional database. We have employed AI models to predict surgical complexity and postoperative outcomes. Furthermore, we have applied SHapley Additive exPlanations (SHAP) to make the AI models interpretable. Finally, we analyzed the surgeries not converted to open versus those converted to open. RESULTS: Overall, 585 patients and 22 variables were included. Multi-layer Perceptron (MLP) showed the highest performance for predicting surgery complexity and Random Forest (RF) for predicting postoperative outcomes. SHAP detected that MLP and RF gave the highest relevance to the variables "resection type" and "largest tumor size" for predicting surgery complexity and postoperative outcomes. In addition, we explored between surgeries converted to open and non-converted, finding statistically significant differences in the variables "tumor location," "blood loss," "complications," and "operation time." CONCLUSION: We have observed how the application of SHAP allows us to understand the predictions of AI models in surgical complexity and the postoperative outcomes of laparoscopic liver surgery in segments 7 and 8.

Risk-Adjusted Assessment of the Learning Curve for Pure Laparoscopic Donor Hepatectomy for Adult Recipients.

BACKGROUND: Studies on pure laparoscopic donor hepatectomy (PLDH) have been reported. However, only few studies have reported on the learning curve of PLDH. In this report, we aimed to determine the learning curve of PLDH in adult patients using cumulative sum (CUSUM) and risk-adjusted CUSUM (RA-CUSUM) analyses. METHODS: The data of donors who underwent PLDH at a single center between December 2012 and May 2022 were retrospectively reviewed. The learning curve was evaluated using the CUSUM and RA-CUSUM methods based on surgery duration. RESULTS: Forty-eight patients were finally included in the present study. The mean operation time was 393.6 ± 80.3 min. PLDH was converted to laparotomy in three cases (6.3%). According to the Clavien-Dindo classification, nine cases (18.8%) had higher-than-grade III postoperative complications and the most frequent complications were biliary complications. The CUSUM graph shows two peaks, at the 13th and 27th case. The multivariate analysis revealed that a body mass index ≥ 23 kg/m2 and intraoperative cholangiography were the only factors that were independently associated with longer operation time. Based on these results, an RA-CUSUM analysis was performed to assess the learning curve, which showed a decrease in the learning curve after 33 to 34 PLDH procedures. CONCLUSIONS: A learning curve effect was demonstrated in this study after 33 to 34 PLDH procedures. There are relatively many biliary complications, and it is necessary to further examine the method of bile duct transection.

Prediction and association analyses of skin phenotypes in Japanese females using genetic, environmental, and physical features.

BACKGROUND: Skin characteristics show great variation from person to person and are affected by multiple factors, including genetic, environmental, and physical factors, but details of the involvement and contributions of these factors remain unclear. OBJECTIVES: We aimed to characterize genetic, environmental, and physical factors affecting 16 skin features by developing models to predict personal skin characteristics. METHODS: We analyzed the associations of skin phenotypes with genetic, environmental, and physical features in 1472 Japanese females aged 20-80 years. We focused on 16 skin characteristics, including melanin, brightness/lightness, yellowness, pigmented spots, wrinkles, resilience, moisture, barrier function, texture, and sebum amount. As genetic factors, we selected 74 single-nucleotide polymorphisms of genes related to skin color, vitamin level, hormones, circulation, extracellular matrix (ECM) components and ECM-degrading enzymes, inflammation, and antioxidants. Histories of ultraviolet (UV) exposure and smoking as environmental factors and age, height, and weight as physical factors were acquired by means of a questionnaire. RESULTS: A linear association with age was prominent for increase in the area of crow's feet, increase in number of pigmented spots, decrease in forehead sebum, and increase in VISIA wrinkle parameters. Associations were analyzed by constructing linear regression models for skin feature changes and logistic regression models to predict whether subjects show lower or higher skin measurement values in the same age groups. Multiple genetic factors, history of UV exposure and smoking, and body mass index were statistically selected for each skin characteristic. The most important association found for skin spots, such as lentigines and wrinkles, was adolescent sun exposure. CONCLUSION: Genetic, environmental, and physical factors associated with interindividual differences of the selected skin features were identified. The developed models should be useful to predict the skin characteristics of individuals and their age-related changes.

Establishment and validation of visual assessment for the severity of lacrimal groove wrinkles in Chinese females.

OBJECTIVE: This study was undertaken to establish and validate a new wrinkle clinical assessment scale to measure Chinese Han women`s validated lacrimal groove. METHODS: Three clinical investigators asked to rate lacrimal groove wrinkles severity one each side for 30 photographic images from 15 subjects. Five-grade rating scale has been used in this clinical assessment. Scale definitions was standardized by 6 researchers in visual and descriptive formats. Assessments were conducted independently and were repeated after 1 week. RESULTS: For 30 photos from 15 subjects, test-retest of three investigators analyzed by Spearman's correlation were between 0.967 and 0.993 (p < 0.001), and by ICC Cronbach's α were between 0.989 and 0.997 (p < 0.001); intraobserver agreement of three investigators analyzed by Spearman's correlation were between 0.652 and 0.897 (p < 0.001), and by ICC Cronbach's α were between 0.840 and 0.959 (p < 0.001). CONCLUSION: This lacrimal groove wrinkles visual assessment scale is a valid and reliable instrument for quantitative assessment of China woman skin folds with inter- and intraobserver consistency. This assessment scale should prove a useful clinical tool by allowing objective and reproducible grading for assessing the effectiveness of lacrimal groove area.

Basement Membrane Helps Maintain Epidermal Hyaluronan Content.

Hyaluronan (HA) is the major glycosaminoglycan in the extracellular matrix of most mammalian tissues, including the epidermis. It is synthesized in epidermis, and mainly metabolized after transfer to the liver via lymphatic vessels in the dermis following its passage through the basement membrane (BM) at the dermal-epidermal junction. The aim of the present study was to investigate the influence of BM integrity on the level of HA in the epidermis. Epidermal HA content was decreased in sun-exposed skin of older subjects, whose BM structure was impaired, compared with sun-exposed young skin and sun-protected skin, in which BM integrity was well maintained. In an organotypic culture model of sun-exposed facial skin, epidermal HA was increased in the presence of inhibitors of BM-degrading matrix metalloproteinases and heparanase. In a skin equivalent model treated with these inhibitors, HA content was increased in the epidermis, but decreased in conditioned medium. These findings suggest that the BM at the dermal-epidermal junction plays an important role in maintaining epidermal HA levels.

Quantitative characterization of 3D structure of vellus hair arrector pili muscles by micro CT.

BACKGROUND: Vellus hair is the fine, wispy hair found over most of the body surface, and the arrector pili muscles (hair muscle) serve to raise these hairs. Hair muscles are also critical for skin regeneration, contributing to the maintenance of stem cells in epidermis and hair follicles. However, little is known about their fundamental properties, especially their structure, because of the limitations of conventional two-dimensional histological analysis. OBJECTIVES: We aimed to quantitatively characterize the structure of vellus hair muscles by establishing a method to visualize the 3D structure of hair muscle. METHODS: We observed young female abdominal skin specimens by means of X-ray micro CT and identified hair muscles in each cross-sectional CT image. We then digitally reconstructed the 3D structure of the hair muscles on computer (digital-3D skin), and numerically evaluated their structural parameters. RESULTS: Vellus hair muscles were clearly distinguished from the surrounding dermal layer in X-ray micro CT images and were digitally reconstructed in 3D from those images for quantification of the structural parameters. The mean value of number of divisions of vellus hair muscles was 1.6, mean depth was 943.6 µm from the skin surface, mean angle to the skin surface was 28.8 degrees, and mean length was 1657.9 µm. These values showed relatively little variation among subjects. The mean muscle volume was approximately 20 million µm3 but showed greater variability than the other parameters. CONCLUSION: Digital-3D skin technology is a powerful approach to understand the tiny but complex 3D structure of vellus hair muscles. The fundamental nature of vellus hair muscles was characterized in terms of their 3D structural parameters, including number of divisions, angle to the skin surface, depth, and volume.

Infiltration of subcutaneous adipose layer into the dermal layer with aging.

BACKGROUND: The elasticity of the dermal layer decreases with aging, leading to ulcer formation and wrinkling, but the mechanism of this change is not fully understood, because it is difficult to access the complex three-dimensional (3D) internal structure of the dermis. OBJECTIVE: To clarify age-dependent changes in the overall 3D structure of the dermal layer by means of 3D analysis technology. METHODS: We observed sun-protected human skin by means of X-ray micro CT, identified the layers of the skin, and reconstructed the 3D structure on computer. Age-dependent structural changes of the dermal layer were evaluated by statistical comparison of young and aged skin. RESULTS: Histological observations suggested the presence of two types of ectopic fat deposits, namely infiltrated subcutaneous fat and isolated fat, in the lower region of the reticular dermal layer in aged skin. To elucidate their nature, we observed skin specimens by X-ray microCT. The epidermis, dermal layer, and subcutaneous adipose layer were well differentiated on CT images, and 3D skin was digitally reconstructed on computer. This method clearly showed that the isolated fat observed histologically was in fact connected to the subcutaneous fat, namely all ectopic fat is connected to the subcutaneous adipose layer. Statistical analysis showed that the severity of fat infiltration into dermal layer is significantly increased in aged skin compared with young skin. CONCLUSION: Our findings indicate that subcutaneous fat infiltrates into the dermal layer of aged skin. Our 3D analysis approach is advantageous to understand changes of complex internal skin structures with aging.

Fat infiltration into dermal layer induces aged facial appearance by decreasing dermal elasticity.

BACKGROUND: Facial morphology changes with aging, producing an aged appearance, but the mechanisms involved are not fully established. We recently showed that subcutaneous fat infiltrates into the dermal layer with aging, but it is not yet clear whether and how this drastic change of the dermal layer influences facial appearance. PURPOSE: We aimed to establish the role of fat infiltration in producing an aged facial appearance and to clarify the mechanism involved. METHODS: We analyzed the severity of fat infiltration in cheek skin of 30 middle-aged female volunteers by means of ultrasonography. Severity of the nasolabial fold, an established age-related morphology, was evaluated based on our photographic grading criteria as a measure of aged appearance. Skin elasticity was measured with a Cutometer. RESULTS: Fat infiltration to the dermal layer was detected at the cheek skin noninvasively by means of ultrasonography. Fat infiltration severity, measured as the minimum depth of the fat inside the dermal layer from the skin surface, was positively correlated with the magnitude of the nasolabial fold. Further, fat infiltration severity was significantly negatively correlated with dermal elasticity. CONCLUSIONS: Our results suggest that fat infiltration into the dermal layer is a critical factor inducing aged appearance of the face. The infiltrated fat decreases the dermal elasticity, which exacerbates nasolabial folds, namely producing an aged facial appearance.

Hard bilateral syphilitic testes with vasculitis: a case report and literature review.

BACKGROUND: We report the case of a patient with syphilitic testicular gumma and vasculitis with adrenal failure due to chronic steroid use. CASE PRESENTATION: A 63-year-old male presented with hard right eye swelling and very firm bilateral testes on palpation, which he had for 2 years. Testicular tumor markers were negative; syphilis test was positive. Radiological examination suggested aortitis and bilateral testicular malignancy. The patient received ampicillin for the infection and prednisolone for vasculitis. Left orchidectomy was performed to confirm the presence of testicular tumor; histological examinations revealed granulomatous orchitis. The prednisolone doses were adjusted because of relapses and adverse effects of steroid use. Unfortunately, the patient died in the intensive care unit because of uncontrolled blood pressure and pneumonia. CONCLUSIONS: This is a rare case of syphilis with testicular involvement and vasculitis. This report shows the importance of broadening the differential diagnoses of testicular firmness.

Aging-related shift of eccrine sweat glands toward the skin surface due to tangling and rotation of the secretory ducts revealed by digital 3D skin reconstruction.

BACKGROUND: Sweat gland function deteriorates with aging, leading to loss of heat tolerance. However, it is unclear whether and how the structure of sweat glands changes during aging, because the 3D structure is complex and inaccessible. METHODS: To clarify age-dependent changes in sweat glands, we developed a method for 3D structure analysis of sweat glands by means of X-ray micro-CT observation of human skin specimens followed by 3D digital reconstruction on computer (digital 3D skin). RESULTS: Comparison of eccrine sweat glands of abdominal skin from young and old subjects showed that the density and volume of sweat glands do not change with aging. In contrast, the depth of the secretory coil from the skin surface is decreased in the aged group. Surprisingly, the secretory ducts appear tortuous or meandering though their length is unchanged. The secretory coils are located at the dermal-adipose layer boundary in both groups, but the thickness of the dermal layer decreases with aging, and the depth of the coils is correlated with the dermal thickness. CONCLUSION: Our results suggest that sweat glands twist and rotate with aging to maintain the position of the coil at the dermal-adipose boundary, causing an overall shift toward the skin surface.

1-(2-Hydroxyethyl)-2-imidazolidinone, a heparanase and matrix metalloproteinase inhibitor, improves epidermal basement membrane structure and epidermal barrier function.

Daily exposure to sunlight is known to affect the structure and function of the epidermal basement membrane (BM), as well as epidermal differentiation and epidermal barrier function. The aim of this study is to clarify whether the inhibition of BM-degrading enzymes such as heparanase and matrix metalloproteinase 9 (MMP-9) can improve the epidermal barrier function of facial skin, which is exposed to the sun on a daily basis. 1-(2-hydroxyethyl)-2-imidazolidinone (HEI) was synthesized as an inhibitor of both heparanase and MMP-9. HEI inhibited not only the BM damage at the DEJ but also epidermal proliferation, differentiation, water contents and transepidermal water loss abnormalities resulting from ultraviolet B (UVB). This was determined in this study by the use of UVB-induced human cultured skins as compared with the control without HEI. Moreover, topical application of HEI improved epidermal barrier function by increasing water content and decreasing transepidermal water loss in daily sun-exposed facial skin as compared with non-treated skins. These results suggest that the inhibition of both heparanase and MMP-9 is an effective way to care for regularly sun-exposed facial skin by protecting the BM from damage.

Outcomes of esophagectomy after chemotherapy with biweekly docetaxel plus cisplatin and fluorouracil for advanced esophageal cancer: a retrospective cohort analysis.

BACKGROUND: Docetaxel, cisplatin, and 5-fluorouracil (DCF) therapy can cause severe adverse events, including neutropenia and febrile neutropenia. The feasibility of DCF therapy is a concern, particularly for elderly patients, patients with moderate organ disorders, and patients suffering from malnutrition caused by dysphagia or insufficient oral intake. We introduced a biweekly DCF therapy (bDCF) for the purpose of reducing severe adverse events for these fragile patients. This study investigated the feasibility and outcome of an esophagectomy after bDCF therapy for patients with advanced esophageal squamous cell carcinoma. METHODS: Fifty-nine patients with esophageal carcinoma underwent an esophagectomy after DCF or bDCF therapy as primary chemotherapy. DCF was administered to 37 patients in the DCF group, whereas bDCF was administered to 22 patients in the bDCF group. RESULTS: Patients in the bDCF group were significantly older than those in the DCF group (p = 0.016). Heart and pulmonary comorbidities were significantly more common in the bDCF than in the DCF group (p < 0.001 and p = 0.039, respectively). Grade 3 or 4 neutropenia was less frequent in the bDCF than in the DCF group (40.9 vs. 81.1%, p = 0.002). Anorexia was more frequent in the DCF group than in the bDCF group (18.9 vs. 0%, p = 0.030). The clinical response rate of the bDCF group was significantly higher than that of the DCF group (86.4 vs. 62.2%, p = 0.047). There was no significant between-group difference in the postoperative morbidity rate (bDCF 45.5% vs. DCF 32.4%) or in the histological therapeutic effect. CONCLUSION: The results demonstrate that primary bDCF therapy for high-risk patients with advanced esophageal cancer is feasible and safe in both chemotherapeutic and perioperative periods without a reduction in the efficacy of DCF therapy.

Characterization and mechanisms of photoageing-related changes in skin. Damages of basement membrane and dermal structures.

Sun-exposed skin is characterized by superficial changes such as wrinkles, sagging and pigmentary changes, and also many internal changes in the structure and function of epidermis, basement membrane (BM) and dermis. These changes (so-called photoageing) are predominantly induced by the ultraviolet (UV) component of sunlight. Epidermis of UV-irradiated skin produced several enzymes such as matrix metalloproteinases (MMPs), urinary plasminogen activator (uPA)/plasmin and heparanase, which degrade dermal collagen fibres and elastic fibres in the dermis, and components of epidermal BM. The BM at the dermal-epidermal junction (DEJ) controls dermal-epidermal signalling and plays an important role in the maintenance of a healthy epidermis and dermis. BM is repetitively damaged in sun-exposed skin compared with unexposed skin, leading to epidermal and dermal deterioration and accelerated skin ageing. UV exposure also induces an increase in vascular endothelial growth factor (VEGF), an angiogenic factor, while thrombospondin-1 (TSP-1), an anti-angiogenic factor, is decreased; these changes induce angiogenesis in papillary dermis with increased migration of elastase-positive leucocytes, leading to dermal elastic fibre damage. Elastic fibres, such as oxytalan fibres in papillary dermis, are associated with not only skin resilience, but also skin surface texture, and elastic fibre formation by fibroblasts is facilitated by increased expression of fibulin-5. Thus, induction of fibulin-5 expression is a damage-repair mechanism, and fibulin-5 is an early marker of photoaged skin. UV-induced skin damage is cumulative and leads to premature ageing of skin. However, appropriate daily skincare may ameliorate photoageing by inhibiting processes causing damage and enhancing repair processes.

Changes in fibrillin-1 expression, elastin expression and skin surface texture at sites of cultured epithelial autograft transplantation onto wounds from burn scar excision.

This study investigated the recovery process during which grafted cultured epithelium generated skin elasticity and skin surface microarchitecture. The subjects were 18 patients whose burn scars were excised at a depth not exposing the fat layer and who subsequently received cultured epithelial autografts. A total of 24 samples were obtained from the grafted sites: 6 samples within 6 weeks (stage 1), 5 samples after 6 weeks and within 6 months (stage 2), 6 samples after 6 months and within 18 months (stage 3) and 7 samples beyond 18 months (stage 4) of transplantation. These samples were evaluated by taking replicas of skin surface, and histological changes of fibrillin-1 and elastin. The expression patterns were classified using a grading scale. The grade of skin surface texture was significantly higher at stage 3 and marginally significantly higher at stage 4 compared with stage 1. The grade of fibrillin-1 was marginally significantly higher at stage 3 and significantly higher at stage 4 compared with stage 1. The grade of elastin was marginally significantly higher at stage 4 compared with stage 1. These results showed that it is important for patients to have skin care and avoid external forces for at least 18 months after transplantation.

Changes in the expression of epidermal differentiation markers at sites where cultured epithelial autografts were transplanted onto wounds from burn scar excision.

This study investigated the recovery process during which grafted cultured epithelium formed normal epidermis. The subjects were 18 patients whose burn scars were excised at a depth not exposing the fat layer and who subsequently received cultured epithelial autografts. A total of 24 samples were obtained from the grafted sites: 6 samples within 6 weeks (stage 1), 5 samples after 6 weeks and within 6 months (stage 2), 6 samples after 6 months and within 18 months (stage 3) and 7 samples beyond 18 months (stage 4) after transplantation. These samples were stained for monoclonal antibodies against filaggrin, transglutaminase (TG), cytokeratin 6 and involucrin. Their expressions were examined in the epidermis. The expression patterns were classified using a six-grade scale. The grades of filaggrin and TG were significantly higher at stage 3 and 4 compared with stage 1. There was a marginally significant increase in the grade of cytokeratin 6 at stage 3 and it was significantly higher at stage 4 compared with stage 1. These results showed that wound healing continued at a molecular level until the end of stage 3. The recovery of involucrin was delayed compared with that of other markers. TG and involucrin are thought to be regulated independently at the grafted sites.

Increment of subcutaneous adipose tissue is associated with decrease of elastic fibres in the dermal layer.

Obesity is a significant risk factor for various skin disorders, including pressure ulcer and delayed wound healing. We previously showed that increment of subcutaneous adipose tissue contributes to poor skin condition by decreasing dermal elasticity. Here, we examined the mechanism involved. Histologic observation of abdominal skin from middle-aged females with a wide range of body mass index (BMI), an indicator of subcutaneous fat mass, showed that dermal elastic fibre abundance was significantly decreased with increment of BMI. Concomitantly, adipocytes were significantly enlarged. Adipocyte enlargement was significantly negatively correlated with dermal elastic fibre abundance. We hypothesized that enlarged adipocytes negatively influence dermal elastic fibres, so we investigated elastic fibre-degrading factors in in vitro-cultured enlarged adipocytes. MMP9 gene expression and secretion were significantly increased; further, these changes were blocked by extracellular signal-regulated kinase (ERK) inhibitor. Nuclear translocation (activation) of AP-1, a downstream ERK signalling molecule, was also observed in enlarged adipocytes. MMP9 abundance was significantly increased in skin of subjects with high BMI and enlarged adipocytes. These results suggest that increment of subcutaneous adipose tissue leads to adipocyte enlargement together with increased degradation of dermal elastic fibres, mediated at least in part by an ERK signalling-mediated increase of MMP9 in enlarged adipocytes.

Repeated folding stress-induced morphological changes in the dermal equivalent.

BACKGROUND/PURPOSE: Repeated mechanical stresses applied to the same region of the skin are thought to induce morphological changes known as wrinkle. However, the underlying mechanisms are not fully understood. To study the mechanisms, we examined effects of repeated mechanical stress on the dermal equivalent. METHODS: We developed a novel device to apply repeated folding stress to the dermal equivalent. After applying the mechanical stress, morphological changes of the dermal equivalent and expression of several genes related to extracellular matrix turn over and cell contraction were examined. RESULTS: The repeated folding stress induced a noticeable decrease in the width of the dermal equivalent. The mechanical stress altered orientations of collagen fibrils. Hydroxyproline contents, dry weights and cell viability of the dermal equivalents were not affected by the mechanical stress. On the other hand, Rho-associated coiled-coil-containing kinase (ROCK) specific inhibitor Y27632 completely suppressed the decrease in the width of the dermal equivalent. CONCLUSION: The present results revealed that either degradation of collagen or changes in the number of cells were not responsible for the decrease in the width of the dermal equivalent and indicate that the repeated mechanical stress induces unidirectional contraction in the dermal equivalent through the RhoA-ROCK signaling pathway.

Safety and Feasibility of Laparoscopic Parenchymal-Sparing Hepatectomy for Lesions with Proximity to Major Vessels in Posterosuperior Liver Segments 7 and 8.

Laparoscopic parenchymal-sparing hepatectomy (PSH) for lesions with proximity to major vessels (PMV) in posterosuperior segments (PSS) has not yet been sufficiently examined. The aim of this study is to examine the safety and feasibility of laparoscopic PSH for lesions with PMV in PSS 7 and 8. We retrospectively reviewed the outcomes of laparoscopic liver resection (LLR) and open liver resection (OLR) for PSS lesions and focused on patients who underwent laparoscopic PSH for lesions with PMV in PSS. Blood loss was lower in the LLR group (n = 110) than the OLR group (n = 16) (p = 0.009), and no other short-term outcomes were significantly different. Compared to the pure LLR group (n = 93), there were no positive surgical margins or complications in hand-assisted laparoscopic surgery (HALS) (n = 17), despite more tumors with PMV (p = 0.009). Regarding pure LLR for one tumor lesion, any short-term outcomes in addition to the operative time were not significantly different between the PMV (n = 23) and no-PMV (n = 48) groups. The present findings indicate that laparoscopic PSH for lesions with PMV in PSS is safe and feasible in a matured team, and the HALS technique still plays an important role.

Comparison of olanexidine versus povidone-iodine as a preoperative antiseptic for reducing surgical site infection in both scheduled and emergency gastrointestinal surgeries: A single-center randomized clinical trial.

Aim: Surgical site infection (SSI) is one of the most common postoperative complications in gastrointestinal surgery. To clarify the superiority of 1.5% olanexidine, we conducted a randomized prospective clinical trial that enrolled patients undergoing gastrointestinal surgery with operative wound classes II-IV. Methods: To evaluate the efficacy of 1.5% olanexidine in preventing SSIs relative to 10% povidone-iodine, we enrolled 298 patients in each group. The primary outcome was a 30-day SSI, and the secondary outcomes were incidences of superficial and deep incisional SSI and organ/space SSI. In addition, subgroup analyses were performed. Results: The primary outcome of the overall 30-day SSI occurred in 38 cases (12.8%) in the 1.5% olanexidine group and in 53 cases (18.0%) in the 10% povidone-iodine group (adjusted risk ratio: 0.716, 95% confidence interval: 0.495-1.057, p = 0.083). Organ/space SSI occurred in 18 cases (6.1%) in the 1.5% olanexidine group and in 31 cases (10.5%) in the 10% povidone-iodine group, with a significant difference (adjusted risk ratio: 0.587, 95% confidence interval: 0.336-0.992, p = 0.049). Subgroup analyses revealed that SSI incidences were comparable in scheduled surgery (relative risk: 0.809, 95% confidence interval: 0.522-1.254) and operative wound class II (relative risk: 0.756, 95% confidence interval: 0.494-1.449) in 1.5% olanexidine group. Conclusion: Our study revealed that 1.5% olanexidine reduced the 30-day overall SSI; however, the result was not significant. Organ/space SSI significantly decreased in the 1.5% olanexidine group. Our results indicate that 1.5% olanexidine has the potential to prevent SSI on behalf of povidone-iodine.