Evolution of Three-Dimensional Computed Tomography Imaging in Thoracic Surgery.

Radiologic reconstruction technology allows the wide use of three-dimensional (3D) computed tomography (CT) images in thoracic surgery. A minimally invasive surgery has become one of the standard therapies in thoracic surgery, and therefore, the need for preoperative and intraoperative simulations has increased. Three-dimensional CT images have been extensively used, and various types of software have been developed to reconstruct 3D-CT images for surgical simulation worldwide. Several software types have been commercialized and widely used by not only radiologists and technicians, but also thoracic surgeons. Three-dimensional CT images are helpful surgical guides; however, in almost all cases, they provide only static images, different from the intraoperative views. Lungs are soft and variable organs that can easily change shape by intraoperative inflation/deflation and surgical procedures. To address this issue, we have developed a novel software called the Resection Process Map (RPM), which creates variable virtual 3D images. Herein, we introduce the RPM and its development by tracking the history of 3D CT imaging in thoracic surgery. The RPM could help develop a real-time and accurate surgical navigation system for thoracic surgery.

Bronchial occlusion with endobronchial Watanabe spigots using a two-scope technique for massive haemoptysis.

Massive haemoptysis is a life-threatening condition whose cause needs to be identified rapidly so that prompt interventions can ensue. Bronchial occlusion with endobronchial Watanabe spigots (EWSs) may be useful when endovascular treatment or surgery proves to be difficult. An 84-year-old woman developed massive haemoptysis during percutaneous mitral valve repair for refractory heart failure due to severe mitral regurgitation (MR). Interventional radiology (IVR) and surgery were contraindicated, and bronchial occlusion with EWSs was attempted to control bleeding. The bleeding was so persistent that it was difficult to secure the visual field without aspiration with a bronchoscope. Herein, we report a two-scope technique, also used in cryobiopsy of peripheral lung lesions, to control bleeding and perform bronchial occlusion with EWSs.

Development of a machine learning-based risk model for postoperative complications of lung cancer surgery.

PURPOSE: To develop a comorbidity risk score specifically for lung resection surgeries. METHODS: We reviewed the medical records of patients who underwent lung resections for lung cancer, and developed a risk model using data from 2014 to 2017 (training dataset), validated using data from 2018 to 2019 (validation dataset). Forty variables were analyzed, including 35 factors related to the patient's overall condition and five factors related to surgical techniques and tumor-related factors. The risk model for postoperative complications was developed using an elastic net regularized generalized linear model. The performance of the risk model was evaluated using receiver operating characteristic curves and compared with the Charlson Comorbidity Index (CCI). RESULTS: The rate of postoperative complications was 34.7% in the training dataset and 21.9% in the validation dataset. The final model consisted of 20 variables, including age, surgical-related factors, respiratory function tests, and comorbidities, such as chronic obstructive pulmonary disease, a history of ischemic heart disease, and 12 blood test results. The area under the curve (AUC) for the developed risk model was 0.734, whereas the AUC for the CCI was 0.521 in the validation dataset. CONCLUSIONS: The new machine learning model could predict postoperative complications with acceptable accuracy. CLINICAL REGISTRATION NUMBER: 2020-0375.

A Case of Incidentally Discovered Congenital Complete Pericardial Defect during Lobectomy for Lung Cancer: A Case Report and Literature Review.

An 82-year-old male patient underwent a left upper lobectomy with anterolateral thoracotomy for lung cancer. Although a complete left-pericardial defect was observed during surgery, the pericardial repair was not performed because the left lower lobe remained and the heart was considered stable. Postoperative pathological examination revealed primary synchronous double-lung squamous-cell carcinoma (pathological stage pT2a(2)N0M0 stage IB). He was discharged without complications on postoperative day 8. Leftward displacement of the heart and left diaphragmatic elevation, suspected of phrenic-nerve paralysis, were found in the chest X-ray after discharge. However, the patient's overall condition remained unaffected at the 5-month postoperative follow-up. To assess the need for pericardial repair, we compared cases of complete pericardial defects observed during lobectomy or pneumonectomy reported in the literature. Only one of 12 cases occurred postoperative death despite pericardial repair, and that case combined pectus excavatum and pericardial defects. Our assessment indicated that pericardial repair might not be necessary, excluding complex cases.

The Tumor Immune Microenvironment Is Associated With Recurrence in Early-Stage Lung Adenocarcinoma.

Introduction: Immune checkpoint inhibitors have recently been approved for the treatment of early-stage NSCLC in the perioperative setting on the basis of phase 3 trials. However, the characteristics of such patients who are susceptible to recurrence after adjuvant chemotherapy or who are likely to benefit from postoperative immunotherapy have remained unclear. Methods: This biomarker study (WJOG12219LTR) was designed to evaluate cancer stem cell markers (CD44 and CD133), programmed death-ligand 1 (PD-L1) expression on tumor cells, CD8 expression on tumor-infiltrating lymphocytes, and tumor mutation burden in completely resected stage II to IIIA NSCLC with the use of archived DNA and tissue samples from the prospective WJOG4107 trial. Tumors were classified as inflamed or noninflamed on the basis of the PD-L1 tumor proportion score and CD8+ tumor-infiltrating lymphocyte density. The association between each potential biomarker and relapse-free survival (RFS) during adjuvant chemotherapy was assessed by Kaplan-Meier analysis. Results: A total of 117 patients were included in this study. The median RFS was not reached (95% confidence intervals [CI]: 22.4 mo-not reached; n = 39) and 23.7 months (95% CI: 14.5-43.6; n = 41) in patients with inflamed or noninflamed adenocarcinoma, respectively (log-rank p = 0.02, hazard ratio of 0.52 [95% CI: 0.29-0.93]). Analysis of the combination of tumor inflammation category and TP53 mutation status revealed that inflamed tumors without TP53 mutations were associated with the longest RFS. Conclusions: PD-L1 expression on tumor cells, CD8+ T cell infiltration, and TP53 mutation status may help identify patients with early-stage NSCLC susceptible to recurrence after adjuvant chemotherapy.

Lung cancer after kidney transplantation: a 50-year experience at a single institution.

PURPOSE: To investigate the clinical characteristics of lung cancer that develops after kidney transplantation. METHODS: The clinical data of patients with lung cancer diagnosed after kidney transplantation were collected retrospectively. The medical records were extracted from our database. All patients underwent routine chest examination after kidney transplantation. RESULTS: In total, 17 lung tumors were detected in 15 (0.6%) of 2593 patients who underwent kidney transplantation at our institution. Eleven lung tumors were completely resected from a collective 10 patients (surgical group). The remaining five patients did not receive surgical treatment (nonsurgical group). The surgical group underwent wedge resection (n = 5), segmentectomy (n = 1), lobectomy (n = 3), and bilobectomy (n = 1). The pathological stages were 0 (n = 1), IA1 (n = 2), IA2 (n = 4), IA3 (n = 2), and IB (n = 1). The surgical group had a significantly better prognosis than the nonsurgical group. There were no perioperative complications related to kidney transplantation in either group. CONCLUSIONS: Routine chest examination would be useful for the early diagnosis and treatment of lung cancer after kidney transplantation. Moreover, surgical resection for early-stage lung cancer was associated with a better prognosis for kidney transplantation patients.

CHST4 Gene as a Potential Predictor of Clinical Outcome in Malignant Pleural Mesothelioma.

Malignant pleural mesothelioma (MPM) develops primarily from asbestos exposures and has a poor prognosis. In this study, The Cancer Genome Atlas was used to perform a comprehensive survival analysis, which identified the CHST4 gene as a potential predictor of favorable overall survival for patients with MPM. An enrichment analysis of favorable prognostic genes, including CHST4, showed immune-related ontological terms, whereas an analysis of unfavorable prognostic genes indicated cell-cycle-related terms. CHST4 mRNA expression in MPM was significantly correlated with Bindea immune-gene signatures. To validate the relationship between CHST4 expression and prognosis, we performed an immunohistochemical analysis of CHST4 protein expression in 23 surgical specimens from surgically treated patients with MPM who achieved macroscopic complete resection. The score calculated from the proportion and intensity staining was used to compare the intensity of CHST4 gene expression, which showed that CHST4 expression was stronger in patients with a better postoperative prognosis. The median overall postoperative survival was 107.8 months in the high-expression-score group and 38.0 months in the low-score group (p = 0.044, log-rank test). Survival after recurrence was also significantly improved by CHST4 expression. These results suggest that CHST4 is useful as a prognostic biomarker in MPM.

Prognostic impact of adjuvant therapy for cisplatin-unfit patients with non-small-cell lung cancer: A multicenter analysis.

INTRODUCTION: No evidence exists for postoperative adjuvant therapy in elderly or renal dysfunction patients with non-small-cell lung cancer (NSCLC) who are unfit to receive cisplatin (CDDP). Herein, we evaluated the efficacy of postoperative adjuvant therapy for CDDP-unfit patients. MATERIALS AND METHODS: We defined CDDP-unfit patients as those aged ≥75 years or with renal dysfunction based on criteria established by expert panels and from prospective studies. CDDP-fit patients comprised all others. Between 2010 and 2020, among 1,423 patients with pathological stage II-III (8th edition of the AJCC-TNM Classification) NSCLC, 454 were identified as unfit for CDDP. Following propensity score matching in CDDP-unfit patients with and without postoperative adjuvant therapy, we analyzed the overall survival (OS) and disease-free survival (DFS) of each group and assessed the impact of adjuvant therapy on survival. RESULTS: OS was significantly better in patients who received adjuvant therapy than in those who did not (5-year OS rate: 76.1 % vs. 50.0 %, p < 0.01) among 255 propensity score-matched patients. DFS was also significantly better in patients who received adjuvant therapy than in those who did not (5-year OS: 54.6 % vs. 35.1 %, p < 0.01). CONCLUSIONS: Our findings suggest that postoperative adjuvant therapy could be beneficial for CDDP-unfit patients aged ≥75 years or with renal dysfunction. Future studies for CDDP-unfit patients should be designed based on the results of this study to determine the potential benefits of adjuvant therapy.

Efficacy and safety of intraoperative partial spray of 50% glucose for patients with spontaneous pneumothorax.

OBJECTIVES: The management for pneumothorax patients involves surgical intervention, nevertheless postoperative recurrences are often encountered. To reduce the rates of recurrence, thoracic surgeons have experimented with various novel techniques, such as pleural abrasion, chemical pleurodesis, and staple line coverage with absorbable sheets, in addition to bullectomy. And in recent years, there have been reports of the effectiveness of the use of intraoperative glucose intrapleural spray (GIS) containing 50 ml of 50% glucose solution in addition to bullectomy. However, information on the effects and adverse events of GIS is limited. Current study was aimed to assess the efficacy and safety of GIS in preventing recurrence of pneumothorax. PATIENTS AND METHODS: We conducted a retrospective study with 74 cases of bullectomy with or without GIS between 2018 and 2021 at Okazaki City Hospital. Of these cases, 50 received GIS (GIS group) while 24 were treated conservatively (C group). RESULT: The GIS group consisted of 46 males and 4 females, whereas the C group consisted of 23 males and 1 female, with mean ages of 38.5 ± 5.7 years and 30.5 ± 6.7 years, respectively. The GIS group exhibited a mean increase in blood glucose of 23.8 mg/dL postoperatively, and postoperative infections were observed in 2 cases in the GIS group (4.0%) and 2 cases in the C group (8.3%). The NRS scores of the patients in the GIS group and the C group three hours postoperatively were 4.0 and 3.1, respectively (p = 0.28). No prolongation of postoperative drainage period by GIS was observed (1.2 days and 1.4 days in the GIS and C groups, respectively). Postoperative recurrence occurred in two patients from the C group. The postoperative total drainage volumes were 341.8 ± 25.2 ml and 74.2 ± 25.5 ml in the GIS and C groups, respectively, showing a significant increase in drainage volume (p < 0.01). None of them presented dehydration-related symptoms. CONCLUSIONS: The use of intraoperative glucose intrapleural spray is effective and safe in terms of preventing recurrences and postoperative complications.

Thoracoscopic Wedge Resection for Low-Grade Fibromyxoid Sarcoma (Evans Tumor) with Massive Calcification and Originating from the Lung: A Rare Case in an Unexpected Location.

We encountered a rare case of low-grade fibromyxoid sarcoma, which is generally known as Evans tumor, with massive calcification originating from the lung. The patient was a 22-year-old man with Duchenne muscular dystrophy who was referred for a detailed investigation of an intrathoracic tumor with massive calcification. Although our preoperative diagnosis was a solitary fibrous tumor originating from the mediastinum or diaphragm, intraoperative thoracoscopy revealed the tumor arising from the left lower lobe without adhesion to the other organs. Considering his medical history, we aimed to preserve lung function and chose wedge resection, which completely removed the tumor. Based on the pathological findings, the tumor was diagnosed as low-grade fibromyxoid sarcoma with massive calcification originating from the lung. Although extremely rare, this tumor should be considered as a differential diagnosis for a solitary lung mass with massive calcification in young adults.

Immunosuppressive treatment for myasthenia gravis crises improve the taste disorder in patients with thymoma: two case reports.

Background: Taste disorders in patients with thymoma accompanied by myasthenia gravis (MG) is rare. Case Description: The first case was a male in his 50s who underwent surgery for Masaoka stage III type B3 thymoma. He experienced a loss of taste before surgery, which showed no improvement after surgery. Due to a MG crisis 44 days after surgery, the patient underwent intensive treatment with mechanical ventilation, steroid pulse therapy, and intravenous immunoglobulin (IVIG) therapy. The patient recovered taste when he started oral food intake after the treatment for the MG crisis (about 3 months after surgery). Despite the recovery of taste after steroid pulse therapy and IVIG therapy, taste disorder gradually worsened about 1 year and 9 months after surgery, resulting in an almost complete loss of sweet taste 2 years after surgery. The second case was a male in his 60s who underwent surgery for Masaoka stage II type B1 thymoma. He experienced loss of taste before surgery, which showed no improvement after surgery. Five years and two months after surgery, the patient was diagnosed with a MG crisis and underwent steroid pulse therapy. Along with improvements in MG symptoms, taste disorders gradually improved. After 6 years and 10 months of surgery, the patient is still alive without MG symptoms (only pyridostigmine, 180 mg/body/day), taste disorder, and thymoma recurrence. Conclusions: The autoimmune mechanism may contribute to taste disorders in patients with thymoma, which can be recovered by immunosuppressive treatment in our cases.

Influencing Factors on Intersegmental Identification Adequacy in Segmentectomy with Intraoperative Indocyanine Green (ICG) Intravenous Administration.

Accurate identification of the intersegmental plane is essential in segmentectomy, and Indocyanine Green (ICG) assists in visualizing lung segments. Various factors, including patient-related, intraoperative, and technical issues, can influence boundary delineation. This study aims to assess the rate of unsuccessful intersegmental identification and identify the contributing factors. We analyzed cases of lung segmentectomy from April 2020 to March 2023, where intraoperative ICG was intravenously administered during robot-assisted or video-assisted thoracoscopic surgery. Cases where fluorescence extended beyond expected boundaries within 30 s were classified as the "unclear boundary group". This group was then compared to the "clear boundary group". The study encompassed 111 cases, 104 (94%) of which were classified under the "clear boundary group" and 7 (6%) under the "unclear boundary group". The "unclear boundary group" had a significantly lower DLCO (15.7 vs. 11.8, p = 0.03) and DLCO/VA (4.3 vs. 3.0, p = 0.01) compared to the "clear boundary group". All cases in the "unclear boundary group" underwent lower lobe segmentectomy. ICG administration effectively outlines pulmonary segments. Challenges in segment demarcation may occur in cases with low DLCO and DLCO/VA values, particularly during lower lobe segmentectomy.

Complete visualization using indocyanine green in thoracic surgery for pulmonary sequestration.

Preoperative three-dimensional computed tomography (CT) facilitates accurate identification of aberrant systemic arteries in thoracic surgery for pulmonary sequestration (PS). Furthermore, the boundary between normal and sequestrated lungs can be visualized using the spread of fluorescent indocyanine green (ICG) when performing surgery for PS. This study aimed to determine how to completely visualize anatomical variations, safely treat aberrant arteries, remove only sequestrated lungs, and perform minimally invasive surgery for PS. Seventeen patients underwent lung resection for intralobar PS at our institution between 2009 and 2022. We retrospectively reviewed the surgical outcomes and intraoperative images using ICG to assess the efficacy and feasibility of near-infrared fluorescence imaging. Since 2019, intraoperative near-infrared fluorescence imaging with ICG has been used in six patients, including four females and two males (median age, 56 years), to visualize the boundary between normal and sequestrated lungs. Aberrant arteries were identified using preoperative three-dimensional CT, and the boundary between sequestrated and normal lungs could be clearly delineated intraoperatively using ICG in all cases. The median operative time was 145 min (range, 88-167 min), and the median blood loss was 5 mL (range, 1-191 mL). The overlay mode using near-infrared thoracoscopy, which merges visible light images with fluorescent images, was safer and more useful than conventional thoracoscopy for delineating boundaries with electrocautery. No intraoperative or postoperative complications occurred. The median postoperative hospital stay was 5 days (range, 3-7 days). Intraoperative identification of the boundary between normal and sequestrated lungs using ICG was simple and feasible. We suggested that this technique was effective for lesion resection and normal lung preservation during surgery for intralobar PS.

The consecutive impact of COVID-19 on thoracic surgical procedures in Japan: an analysis of data from the National Clinical Database.

PURPOSE: The current study was designed to analyze the impact of the COVID-19 pandemic on general thoracic surgeries in Japan. METHODS: Changes in surgeries for lung cancer and metastatic lung tumors were evaluated based on National Clinical Database data regarding cancer screening. RESULTS: In 2021, surgeries for primary lung cancer increased by 3.4% compared to 2020, which, given the increase from 2014 to 2019, indicates an overall 11.1% decrease. In contrast, surgeries for metastatic lung tumors in 2021 decreased by 5.8% compared to 2020, which, given the increase from 2014 to 2020, indicates an overall 9.2% decrease. Half of the primary diseases for metastatic lung tumor were cases of colorectal cancer. Low anterior resection procedures in 2020 decreased by 5.5% compared to 2019. Lung and colon cancer screening examinees in 2021 were increased compared to 2020; however, they still showed respective decreases of 11% and 9.0% compared to 2019. CONCLUSIONS: Surgeries for primary lung cancer still decreased substantially during the COVID-19 pandemic. The continued stagnation of screening was responsible for this decrease. Surgeries for metastatic lung tumors decreased profoundly, and the decrease in screening for primary tumors was responsible for this reduction. Our findings emphasize the significance of maintaining cancer screening efforts, even during a pandemic.

New method for delineation of the intersegmental line in a deflated lung.

Background: Preoperative three-dimensional (3D) computed tomography (CT) images have been widely used as surgical guides in lung surgery; however, the lungs tend to be deflated during surgery. Discrepancies between the preoperatively constructed 3D image and the intraoperative view of the deflated lungs often require preoperative and/or intraoperative marking methods for sublobar pulmonary resection. We have developed a lung deflation simulation algorithm in which 3D CT images of the deflated lungs can be predicted only based on the preoperative CT taken in an inflated phase of respiration. Using this system, we conducted a preliminary study to retrospectively compare the intersegmental line predicted by our lung deflation simulation algorithm with the intersegmental line delineated by the intravenous administration of indocyanine green. Methods: Sixteen patients who underwent unilateral segmentectomy between January 1, 2020, and June 30, 2022, were included in the study. The identified intersegmental lines were confirmed intraoperatively using indocyanine green. These actual intersegmental lines were compared with those delineated on 3D images using the lung deflation simulation algorithm. Results: Of the 16 patients who underwent pulmonary segmentectomy, the consistency of these intersegmental lines was in complete agreement in twelve patients, partial agreement in three patients, and disagreement in one patient. The concordance rate of the intersegmental lines was 75%. Conclusions: The lung deflation simulation algorithm provides a new surgical guide in addition to the currently utilized ones. Continuous innovation might lead to a less invasive surgical technique for delineating the intersegmental line.

Prognostic impact of highly solid component in early-stage solid lung adenocarcinoma.

Background: Based on computed tomography (CT) findings of lung cancer, solid nodules have a much worse prognosis than subsolid nodules, even if the nodules are subcentimeter in size. There is, however, no systematic method for determining the prognosis of solid tumors on CT. This study aimed to discover the prognostic factor of early-stage solid lung adenocarcinoma using three-dimensional CT volumetry. Methods: Patients with pathological stage I solid lung adenocarcinoma who underwent complete resection between 2007 and 2012 were selected in this retrospective study. Clinicopathological data and preoperative multidetector CT findings, such as tumor size on the two-dimensional axial image, three-dimensional tumor volume between -600 and 199 HU, and three-dimensional solid volume between 0 and 199 HU, which corresponded to highly solid components, were compared between recurrence and non-recurrence. Furthermore, these radiological values were compared to pathological invasive volume (PIV). Results: During this time, 709 patients had their lung cancer completely removed. From this cohort, 90 patients with pathological stage I solid lung adenocarcinoma were selected. In addition, recurrence was found in 26 patients (28.9%). Although two-dimensional axial image, serum carcinoembryonic antigen (CEA) level, and SUVmax on 18F fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) did not differ statistically between recurrent and non-recurrent patients, three-dimensional tumor and solid tumor volume did. Multivariate analysis indicated that three-dimensional solid tumor volume [hazard ratio: 2.440; 95% confidence interval (CI): 1.110-5.361, P=0.026] and epidermal growth factor receptor (EGFR) mutation (hazard ratio: 4.307; 95% CI: 1.328-13.977, P=0.015) were significantly associated with disease-free survival (DFS). When three-dimensional tumor and solid tumor volume were compared to PIV, three-dimensional solid tumor volume (3,091 mm3 on average) showed a highly similar value with PIV (2,930 mm3 on average), whereas three-dimensional tumor volume (6,175 mm3 on average) was significantly larger than PIV (P<0.001). Conclusions: In patients with early-stage solid lung adenocarcinoma, the measurement of three-dimensional solid tumor volume, which is correlated with PIV, accurately predicted the postoperative outcome.

Risk stratification of postoperative pulmonary complications in elderly patients undergoing lung cancer resection: a propensity score-matched study.

Background: In China, lung cancer mainly affects the elderly population. Surgery remains the standard treatment for lung cancer in elderly patients, however, postoperative pulmonary complications (PPCs) are major contributors to morbidity and mortality following lung resection. This study aimed to identify perioperative predictors of PPCs among elderly patients undergoing pulmonary resection for lung cancer to provide evidence for better prevention and intervention for PPCs. Methods: A retrospective study was conducted with 456 patients (age >65 years) undergoing pulmonary resection for lung cancer in Yunnan, China from January 2016 to March 2019. Propensity score matching (PSM) was performed to compare preoperative data and clinical characteristics between the PPC and non-PPC groups, followed by binary logistic regression to evaluate predictors of PPCs. Results: Pulmonary complications occurred in 142/456 (31.1%) patients age >65 years, with pneumonia being the most common event (21.7%). Both PSM and binary logistic regression analysis identified American Society of Anesthesiologists (ASA) class II or those undergoing an open thoracotomy to help prevent the occurrence of PPCs.

Clinical application of resection process map as a novel surgical guide in thoracic surgery.

Resection Process Map (RPM) is a surgical simulation system that uses preoperative three-dimensional computed tomography. Unlike the usual static simulation, this system provides surgeons an individualized dynamic deformation of the lung parenchyma and vessels. RPM was first introduced in 2020. Although the intraoperative usefulness of this system has been evaluated experimentally, there have been no reports on its clinical use. Herein, we presented in detail the first experience on RPM during robot-assisted anatomical lung resection in the real clinical setting.

Lingular-segment torsion after extended left-upper division segmentectomy by video-assisted thoracic surgery with indocyanine green fluorescence imaging.

Lingular-segment torsion after left-upper division segmentectomy (LUDS) is a rare complication, and the cause remains unclear. Here we report the case of a patient who developed lingular-segment torsion after LUDS for multiple lung metastases of breast cancer. One lung nodule was located in the S1 + 2 segment and another between the upper lobe and S6 on an incomplete interlobar fissure. The lung metastases were resected by extended LUDS using video-assisted thoracic surgery with indocyanine green fluorescence imaging. The staple line on the lingular segment was vertically tilted against the interlobar line because of the atypical defect of the fluorescence plane and nodule position. Chest X-ray and contrast-enhanced computed tomography indicated ischemia and torsion of the lingular segment on the second postoperative day, and completion of lingular segmentectomy was performed. This case showed the vertical intersegment staple line during LUDS was one of the important causes of postoperative torsion of the lingular segment.

Enteral liquid ventilation oxygenates a hypoxic pig model.

The potential of extrapulmonary ventilation pathways remains largely unexplored. Here, we assessed the enteral ventilation approach in hypoxic porcine models under controlled mechanical ventilation. 20 mL/kg of oxygenated perfluorodecalin (O2-PFD) was intra-anally delivered by a rectal tube. We simultaneously monitored arterial and pulmonary arterial blood gases every 2 min up to 30 min to determine the gut-mediated systemic and venous oxygenation kinetics. Intrarectal O2-PFD administration significantly increased the partial pressure of oxygen in arterial blood from 54.5 ± 6.4 to 61.1 ± 6.2 mmHg (mean ± SD) and reduced the partial pressure of carbon dioxide from 38.0 ± 5.6 to 34.4 ± 5.9 mmHg. Early oxygen transfer dynamics inversely correlate with baseline oxygenation status. SvO2 dynamic monitoring data indicated that oxygenation likely originated from the venous outflow of the broad segment of large intestine including the inferior mesenteric vein route. Enteral ventilation pathway offers an effective means for systemic oxygenation, thus warranting further clinical development.