Impact of pulmonary vein-first ligation during lobectomy on the postoperative survival and recurrence rates in patients with non-small cell lung cancer: a multicenter propensity score-matched study.

PURPOSE: Surgical manipulation of the lungs increases the number of circulating tumor cells and the subsequent risk of metastasis in patients with lung cancer. This study investigated whether or not ligating the tumor-draining pulmonary vein first during lobectomy could improve the prognosis of these patients. METHODS: We retrospectively evaluated patients who underwent curative lobectomy for solitary nonsmall-cell lung carcinoma between January 2012 and December 2016. We divided the patients into the vein-first group, in which all associated pulmonary veins were dissected and severed before cutting the pulmonary artery, bronchus, or pulmonary fissure, and the other procedure group. RESULTS: Overall, we included 177 and 413 patients in the vein-first and other procedure groups, respectively. Propensity score matching yielded 67 pairs of patients. The 5-year overall survival (85.6% [95% confidence interval, 77.3-94.8%] vs. 69.4% [58.7-81.9%], P = 0.03%) and recurrence-free survival (73.4% [63.3-85.1%] vs. 53.5% [42.5-67.3%], P = 0.02) were significantly better in the vein-first group than in the other procedure group. The cumulative recurrence rate at 5 years post-surgery was significantly lower in the vein-first group than in the other procedure group (21.7% vs. 38.3%, P = 0.04). CONCLUSION: Our study suggests that ligating the pulmonary vein first during lobectomy for lung cancer can improve the overall survival, recurrence-free survival, and cumulative recurrence rate.

Antibody responses induced by the BNT162b2 mRNA COVID-19 vaccine in healthcare workers in a single community hospital in Japan.

INTRODUCTION: The effectiveness of several vaccines against coronavirus disease (COVID-19) has been reported in the real-world setting. However, it is still unknown how long antibodies persist following vaccination and whether or not the persistence of antibodies has a protective effect against COVID-19. METHODS: Healthcare workers who had received two doses of the BNT162b2 mRNA COVID-19 vaccine were enrolled, and a single-center study was conducted at the National Hospital Organization Hakodate National Hospital. Serum samples from all participants were collected 13-21 weeks (median: 20 weeks) after the second dose of vaccination. The antibody titers were measured using an electrochemiluminescence immunoassay (Elecsys® Anti-SARS-CoV-2 S). Data on characteristics of the participants were gathered from patient records and interview sheets. RESULTS: A total of 401 participants, among whom 70.1% were women and the median age was 42 years, were evaluated in this study. None of the participants had a definite COVID-19 history, and all participants who received complete vaccination showed positive antibody titers. The antibody titer was observed to be higher in participants with younger age (p < 0.001) and those who were females (p = 0.028). Despite the higher risk of infection than that of the general public, no vaccinated staff developed breakthrough infections. CONCLUSIONS: This study demonstrates the significant contribution of the BNT162b2 vaccine in the acquisition of anti-SARS-CoV-2S antibodies; therefore, the general population should benefit from these two vaccine doses, which are expected to be protective for at least five months.

Rabbit VX2 lung tumor models can form early nodal metastases.

BACKGROUND: The rabbit squamous cell cancer line, VX2, has been used to generate various tumor models in rabbits. It is notable for its ability to generate nodal metastases. However, the timing and extent of nodal metastases vary by primary inoculation site and methodology. The development of metastases specifically in lung cancer models has not been well-described. We sought to characterize the generation of nodal metastases in rabbit transbronchial VX2 lung tumor models. METHODS: Rabbit VX2 lung tumor models were created in the right lung via transbronchial injection and serially imaged by computed tomography. Rabbits (n = 15) were sacrificed from between 5 and 24 days post-inoculation for collection of the ipsilateral and contralateral paratracheal lymph nodes. These underwent histopathological evaluation for metastases using hematoxylin and eosin as well as cytokeratin AE1/AE3 immunohistochemical staining. RESULTS: Nodal metastases were detectable as early as 1 week after inoculation but were more prevalent with longer inoculation; all rabbits at > 2 weeks post-inoculation had nodal metastases. Contralateral metastases were in general seen later than ipsilateral metastases. Lymph node volume did not predict the likelihood of nodal metastases (p = 0.4 and p = 0.07 for ipsilateral and contralateral nodal metastases, respectively), but primary tumor volume was significantly associated with the likelihood of nodal metastases (p = 0.001 and p = 0.005 for ipsilateral and contralateral nodal metastases, respectively). Ipsilateral metastases were detectable at a tumor diameter of 1 cm; contralateral metastases were more variable but in general required a tumor diameter of 2 cm. CONCLUSIONS: Rabbit transbronchial VX2 lung tumor models generate nodal metastases relatively early after inoculation. These results suggest such models may be valuable tools in the investigation of novel therapeutic modalities relevant for the treatment of both early-stage and locally advanced lung cancer.

A simple and safe surgical technique for nonpalpable lung tumors: One-stop Solution for a nonpalpable lung tumor, Marking, Resection, and Confirmation of the surgical margin in a Hybrid operating room (OS-MRCH).

When performing thoracoscopic partial resections of nonpalpable lung tumors such as ground-glass opacities (GGOs) and small tumors, detecting the location of the lesion and assessing the resection margins can be challenging. We have developed a novel method to ease this difficulty, the One-stop Solution for a nonpalpable lung tumor, Marking, Resection, and Confirmation of the surgical margin in a Hybrid operating room (OS-MRCH), which uses a hybrid operating room wherein the operating table is seamlessly integrated with cone-beam computed tomography (CBCT). We performed the OS-MRCH method on 62 nodules including primary lung cancer presenting with GGO. Identification of the lesion and confirmation of the margin were performed in 58 of the cases, while nodules were detected in all. The frequency of computed tomography (CT) scans performed prior to resection was one time in 51 cases, two times in eight cases, and ≥3 times in three cases. Additional resection was performed in two cases. The median operative time was 85.0 minutes, and the median pathological margin was 11.0 mm. The key advantages of this method are that all surgical processes can be completed in a single session, specialized skill sets are not required, and it is feasible to perform in any facility equipped with a hybrid operating room. To overcome its disadvantages, such as longer operating time and limited patient positioning, we devised various methods for positioning patients and for CT imaging of the resected specimens. OS-MRCH is a simple, useful, and practical method for performing thoracoscopic partial resection of nonpalpable lung tumors.

Developing a Virtual Reality Simulation System for Preoperative Planning of Robotic-Assisted Thoracic Surgery.

Background. Robotic-assisted thoracic surgery (RATS) is now standard for lung cancer treatment, offering advantages over traditional methods. However, RATS's minimally invasive approach poses challenges like limited visibility and tactile feedback, affecting surgeons' navigation through com-plex anatomy. To enhance preoperative familiarization with patient-specific anatomy, we devel-oped a virtual reality (VR) surgical navigation system. Using head-mounted displays (HMDs), this system provides a comprehensive, interactive view of the patient's anatomy pre-surgery, aiming to improve preoperative simulation and intraoperative navigation. Methods. We integrated 3D data from preoperative CT scans into Perspectus VR Education software, displayed via HMDs for in-teractive 3D reconstruction of pulmonary structures. This detailed visualization aids in tailored preoperative resection simulations. During RATS, surgeons access these 3D images through Tile-ProTM multi-display for real-time guidance. Results. The VR system enabled precise visualization of pulmonary structures and lesion relations, enhancing surgical safety and accuracy. The HMDs offered true 3D interaction with patient data, facilitating surgical planning. Conclusions. VR sim-ulation with HMDs, akin to a robotic 3D viewer, offers a novel approach to developing robotic surgical skills. Integrated with routine imaging, it improves preoperative planning, safety, and accuracy of anatomical resections. This technology particularly aids in lesion identification in RATS, optimizing surgical outcomes.

Dose Optimization of Intravenous Indocyanine Green for Malignant Lung Tumor Localization.

Background: Intravenously administered indocyanine green (ICG) accumulates in lung tumors, facilitating their detection via a fluorescence spectrum measurement. This method aids in identifying tumor locations that are invisible to the naked eye. We aim to determine the optimal ICG dose and administration method for accurate tumor identification during lung resection surgeries, utilizing a novel ICG fluorescence spectroscopy system for precise tumor localization. Materials and Methods: ICG should be dissolved in the provided solution or distilled water and administered intravenously approximately 24 h before surgery, beginning with an initial dose of 0.5 mg/kg. If the tumor detection rate is insufficient, the dose may be gradually increased to a maximum of 5.0 mg/kg to determine the optimal dosage for effective tumor detection. This fluorescence spectroscopy during surgery may reveal additional lesions that remain undetected in preoperative assessments. The primary endpoint includes the correct diagnostic rate of tumor localization. The secondary endpoints include the measurement of the intraoperative ICG fluorescence spectral intensity in lung tumors, the assessment of the operability and safety of intraperitoneal ICG administrations, the measurement of the ICG fluorescence spectral intensity in surgical specimens, the comparison of the spectral intensity in lung tissues during collapse and expansion, the correlation between ICG camera images and fluorescence spectral intensity, and the comparison of fluorescence analysis results with histopathological findings. The trial has been registered in the jRCT Clinical Trials Registry under the code jRCTs011230037. Results and Conclusions: This trial aims to establish an effective methodology for localizing and diagnosing malignant lung tumors, thereby potentially improving surgical outcomes and refining treatment protocols.

Acute onset of constrictive pericarditis due to acute myelomonocytic leukemia: A case and literature review.

We herein present a fatal case of constrictive pericarditis (CP) due to acute myelomonocytic leukemia (AMML) in a patient who initially complained of an acute onset of chest pain two days after COVID-19 vaccination. An autopsy revealed pericardial infiltration of leukemic cells. CP is rarely associated with leukemia and only 14 cases have been reported in the literature. The etiology of CP in previous reports included leukemic infiltration, graft-versus-host disease, drug-induced, post-radiation, autoimmune, and otherwise unidentified. This case indicates that leukemic infiltration can cause CP and that clinicians should include leukemia in the differential diagnosis of CP.

A novel edge-marking method in pleural covering with video-assisted thoracic surgery.

Total pleural covering is implemented to reinforce the visceral pleura with surgical sheets. It has been adopted for diffuse cystic lung diseases such as lymphangioleiomyomatosis to prevent pneumothorax and has achieved good results. The procedure is technically demanding, because it is difficult to cover the entire visceral pleura without disarrangement and jamming of surgical sheets, especially during thoracoscopic surgery, where grasping of a wrong site might happen when unfolding the sheets. Herein, we report a technique to cover the entire pleura with dotted line folded sheets to ease the thoracoscopic procedure. We found that the use of this marking method made the procedure easier, with just a little ingenuity, because marking the edges of sheets with dashed lines clarifies the site that should be grasped, thus preventing the incidence of grasping the wrong part of the sheet. Pleural covering with dotted line folded surgical sheets is a useful method for reduced port thoracoscopic surgery.

Tumor-to-thoracic height ratio as an easy method to predict the feasibility of reduced-port video-assisted thoracic surgery for mediastinal lesions in children: a single-center experience.

In the last few decades, reduced-port video-assisted thoracic surgery (RP-VATS) has been developed to minimize surgical invasiveness. Nevertheless, VATS in children can occasionally be difficult because the lesion occupies a small thoracic cavity, limiting the working space. This study aimed to assess the feasibility of RP-VATS for the resection of mediastinal lesions in children in association with the tumor-to-thoracic height ratio (TTH ratio). We reviewed all patients aged ≤10 years who underwent resection for mediastinal lesions in our institute between January 2008 and August 2022. Patients who underwent diagnostic procedures were excluded from this study. The TTH ratio was calculated as tumor height divided by thoracic height. Seven patients in the RP-VATS group and six in the conventional procedures (multi-portal VATS or open surgery) group were included in this study. The TTH ratio was significantly lower in the RP-VATS group than in the conventional procedures group (median, 26.3% vs. 50.8%; P=0.007). The operating time (P=0.01) and duration of drainage (P=0.003) were significantly shorter and the blood loss (P=0.001) was significantly lower in the RP-VATS group than in the conventional procedures group. After adjusting for age, a lower TTH ratio was significantly associated with the completion of RP-VATS (odds ratio: 0.776; 95% confidence interval: 0.529-0.926; P=0.048). In conclusion, RP-VATS can be performed appropriately in carefully selected cases of pediatric mediastinal lesions. A low TTH ratio may predict the feasibility of RP-VATS. Further studies are warranted to determine the criteria for the indications of RP-VATS in children, so that more children can benefit from RP-VATS.

Dual-portal robotic-assisted thoracic surgery (DRATS) as a reduced port RATS: early experiences in three institutions in Japan.

Background: Robotic-assisted thoracic surgery (RATS) has gained increasing interest in recent years, with most procedures performed using the conventional multiportal approach. Uniportal RATS (URATS) approaches have recently been reported in the pursuit of minimally invasive procedures. However, URATS requires specific skills. Herein, we introduce dual-portal RATS (DRATS) performed with two incisions. Methods: Data of DRATS procedures performed from December 2022 to May 2023 were retrospectively reviewed. Twenty patients with lung cancer underwent anatomical lung resections via DRATS performed by our group at three institutes. Results: Among 20 cases of planned DRATS for anatomical pulmonary resections, there were no conversions to thoracotomy and no need for extra ports. The mean surgery time was 121±60 minutes and mean console time was 91±47 minutes. The mean intraoperative blood loss volume was 9.6±12.1 g. The mean duration of chest tube drainage and hospital stay were 2±1 and 5±2 days, respectively. The mean numerical rating scale for pain was 2±1 on the first postoperative day, 1±1 on the third day, and 1±1 at discharge. There were no postoperative complications or mortalities. Conclusions: Our primary experience shows that DRATS is safe and feasible for anatomical lung resection. We consider DRATS to be a very good preliminary step in the future transition to URATS.

Fatal case of subdural empyema caused by Campylobacter rectus and Slackia exigua.

We report a fatal subdural empyema caused by Campylobacter rectus in a 66-year-old female who developed acute onset of confusion, dysarthria, and paresis in her left extremities. A CT scan showed hypodensity in a crescentic formation with a mild mid-line shift. She had a bruise on her forehead caused by a fall several days before admission, which initially raised subdural hematoma (SDH) diagnosis, and a burr hole procedure was planned. However, her condition deteriorated on the admission night, and she died before dawn. An autopsy revealed that she had subdural empyema (SDE) caused by Campylobacter rectus and Slackia exigua. Both microorganisms are oral microorganisms that rarely cause extra-oral infection. In our case, head trauma caused a skull bone fracture, and sinus infection might have expanded to the subdural space causing SDE. CT/MRI findings were not typical for either SDH or SDE. Early recognition of subdural empyema and prompt initiation of treatment with antibiotics and surgical drainage is essential for cases of SDE. We present our case and a review of four reported cases.

High density and proximity of CD8+ T cells to tumor cells are correlated with better response to nivolumab treatment in metastatic pleural mesothelioma.

BACKGROUND: The efficacy of immune checkpoint inhibitors (ICIs) in pleural mesothelioma has recently been established. The response to ICIs can be predicted by quantitative analysis of cells and their spatial distribution in the tumor microenvironment (TME). However, the detailed composition of the TME in pleural mesothelioma has not been reported. We evaluated the association between the TME and response to ICIs in this cancer. METHODS: A retrospective analysis of 22 pleural mesothelioma patients treated with nivolumab in different centers was performed using surgical specimens. Four patients had a partial response to nivolumab (response group) and 18 patients had stable or progressive disease (nonresponse group). The number of CD4, CD8, FoxP3, CK, and PD-L1 positive cells, cell density, and cell-to-cell distance were analyzed by multiplex immunofluorescence. RESULTS: PD-L1 expression did not differ significantly between the response and nonresponse groups. The density of total T cells and of CD8+ T cells was significantly higher in the response than in the nonresponse group. CD8+ T cells were more clustered and located closer to tumor cells, whereas regulatory T cells were located further from tumor cells in the response than in the nonresponse group. CONCLUSIONS: High density and spatial proximity of CD8+ T cells to tumor cells were associated with better response to nivolumab, whereas the proximity of regulatory T cells to tumor cells was associated with worse response, suggesting that the distinct landscape of the TME could be a potential predictor of ICI efficacy in pleural mesothelioma.

Distribution and clinical impact of molecular subtypes with dark zone signature of DLBCL in a Japanese real-world study.

The distribution and clinical impact of cell-of-origin (COO) subtypes of diffuse large B-cell lymphoma (DLBCL) outside Western countries remain unknown. Recent literature also suggests that there is an additional COO subtype associated with the germinal center dark zone (DZ) that warrants wider validation to generalize clinical relevance. Here, we assembled a cohort of Japanese patients with untreated DLBCL and determined the refined COO subtypes, which include the DZ signature (DZsig), using the NanoString DLBCL90 assay. To compare the distribution and clinical characteristics of the molecular subtypes, we used a data set from the cohort of British Columbia Cancer (BCC) (n = 804). Through the 1050 patient samples on which DLBCL90 assay was successfully performed in our cohort, 35%, 45%, and 6% of patients were identified to have germinal center B-cell-like (GCB) DLBCL, activated B-cell-like (ABC) DLBCL, and DZsig-positive (DZsigpos) DLBCL, respectively, with the highest prevalence of ABC-DLBCL, differing significantly from the BCC result (P < .001). GCB-DLBCL, ABC-DLBCL, and DZsigpos-DLBCL were associated with 2-year overall survival rates of 88%, 75%, and 66%, respectively (P < .0001), with patients with DZsigpos-DLBCL having the poorest prognosis. In contrast, GCB-DLBCL without DZsig showed excellent outcomes after rituximab-containing immunochemotherapy. DZsigpos-DLBCL was associated with the significant enrichment of tumors with CD10 expression, concurrent MYC/BCL2 expression, and depletion of microenvironmental components (all, P < .05). These results provide evidence of the distinct distribution of clinically relevant molecular subtypes in Japanese DLBCL and that refined COO, as measured by the DLBCL90 assay, is a robust prognostic biomarker that is consistent across geographical areas.

[A case report of surgical treatment for axillary lymph node metastasis from descending colon cancer].

We report a rare case of a 78-year-old woman with metachronous axillary lymph node metastasis originating from descending colon cancer. Her past medical history included right mastectomy for breast cancer at age 53 and distal gastrectomy for gastric cancer at age 70. She underwent a left hemicolectomy for descending colon adenocarcinoma in April 2011. Four months after that operation, 3 enlarging nodules in the left lung and a swollen left axillary lymph node were detected by computed tomography. No tumor was detected in the left breast by ultrasonography and mammography. The lung tumors were resected thoracoscopically, and the left axillary lymph node was excised. These specimens were histologically diagnosed as moderately differentiated adenocarcinoma, which had metastasized from colon cancer, not from the previous breast or gastric cancer. She received adjuvant chemotherapy with uracil and tegafur (UFT) plus Leucovorin for 6 months and is still alive after 12 months without recurrence.

Parietal pleural small holes found in patients with primary spontaneous pneumothorax associated with relatively mild chest wall flatness: a retrospective study.

Background: During surgery for spontaneous pneumothorax, parietal pleural small holes (PPSHs) are occasionally found around the apex of the intrapleural space; however, this has not been well recognized. Additionally, chest wall flatness is usually observed in patients with primary spontaneous pneumothorax (PSP) and PPSHs. This study aimed to investigate the prevalence of PPSH and evaluate the characteristics of patients with PPSH. We also investigated the degree of chest wall flatness in patients with PPSHs. Methods: We retrospectively reviewed all patients who underwent thoracoscopic surgery for pneumothorax at our department between April 2014 and May 2021. A propensity-matched analysis was used to compare the characteristics of patients with and without PPSH. Results: A total of 490 patients were enrolled in this study. PPSH was found in 45 of 297 (15.2%) patients with PSP and one of 193 (0.5%) patients with secondary pneumothorax. PSP was independently associated with the presence of PPSH after adjusting for age and sex [primary/secondary, odds ratio (OR) =34.3, 95% confidence interval (CI): 4.7-250.9; P<0.001]. Among patients with PSP, the flatness of the chest wall in patients with PPSH was not as severe as that in patients without PPSH {thoracic anteroposterior diameter (APDT) to transverse diameter (TDT) ratio; with PPSH: median =0.517 [interquartile range (IQR) =0.480-0.554] vs. without PPSH: median =0.487 (IQR =0.463-0.529; P=0.031)} after propensity score matching. Conclusions: PPSH is found in a non-negligible proportion of patients with PSP, and patients with PPSHs show a relatively mild flat chest among patients with PSP. Clinicians should be aware of PPSH, and further understanding of this condition may contribute to a better understanding of PSP.

Anatomical segmentectomy under uniportal video-assisted thoracoscopic surgery for early staged non-small cell lung cancer: a case report.

Background: Anatomical segmentectomy has become more and more universal in thoracic surgery because of the increasing detection of pulmonary nodules with ground-glass opacity (GGO), most of which proved early staged non-small cell lung cancer (NSCLC) postoperative. With the advantage of preservation of normal lung tissues, segmentectomy may be performed by surgeons when computed tomography (CT) scan shows pure GGO or multiple GGOs appearing. Especially when the patients with poor cardiopulmonary function or severe comorbidities or in the circumstance of bilateral pulmonary GGOs, segmentectomy can provide opportunities to radically resect all lesions. With the development of minimally invasive surgery technology, uniportal video-assisted thoracoscopic surgery (VATS) has become the regular operative route in many medical centers because it can provide less access trauma, less stress response, less pain, shorter hospital stays, and a lower postoperative complication rate and corresponds well with the idea of "minimally invasive". However, all of the procedures must be performed in one tiny portal, so uniportal VATS anatomical segmentectomy not only needs the skill and patience of surgeons but the effective cooperation of assistants, nurses and anesthetists, and plenty of details must be paid special attention. Case Description: Here we present a video of a patient undergoing S1 segmentectomy of right upper lobectomy (RUL) under uniportal VATS. The chief complaints of the patients was that two pure GGOs in the bilateral upper lobe were found by physical examination for 26 months and he had no symptoms. We performed S1 segmentectomy of RUL under uniportal first time and performed trisegmentectomy of left upper lobectomy (LUL) 3 months later. With routinely follow-up, no evidence of relapse and metastasis disease was found. Conclusions: We think anatomical segmentectomy under uniportal VATS can be a feasible and safe procedure that reduces trauma and has equivalent oncology outcomes to lobectomy in early-stage lung cancer but need a more experienced medical center to perform. Keywords: Uniportal video-assisted thoracoscopic surgery (uniportal VATS); segmentectomy; non-small cell lung cancer (NSCLC); case report.

Thymoma-Related Stiff-Person Syndrome with Successfully Treated by Surgery.

INTRODUCTION: Stiff-person syndrome (SPS) is a rare autoimmune neurological disorder. Paraneoplastic SPS associated with malignant tumors such as thymoma occurs in approximately 5% of all SPS cases. We present a rare case of thymoma accompanied by SPS successfully treated using surgery. PRESENTATION OF CASE: A 26-year-old woman presented with lower limbs convulsions and gait disturbance and complained of leg pain. Cerebrospinal fluid and blood test results showed a high level of anti-glutamic acid decarboxylase (GAD) antibodies. Computed tomography showed anterior mediastinal tumor suggestive of a thymoma. She underwent extended thymectomy, and her symptoms gradually improved after surgery. No evidence of recurrent thymoma and SPS has been observed over 44 months. CONCLUSION: Surgical treatment would be effective for patients with SPS and thymoma.

Presurgical assessment of flow variability in an azygos vein aneurysm using 4D-flow MRI.

Azygos vein aneurysm (AVA) is necessary to prevent pulmonary embolism due to the outflow of a thrombus or rupture of the aneurysm. However, there is no established modality to assess the properties of AVA. Time-resolved three-dimensional phase-contrast magnetic resonance imaging (4D-flow MRI) has been used to examine the hemodynamics in various fields. We report a case of AVA to evaluate the flow variability and adhesions of surrounding tissues using 4D-flow MRI. The findings of the study suggested aneurysm turbulence and the absence of thrombi. The cine image, which showed a sliding wall synchronized to the heartbeat, indicated no adhesion to the superior vena cava. Based on these results, the thoracoscopic approach was deemed possible preoperatively. Thoracoscopic AVA resection was performed, and the postoperative course was uneventful. This study documented the utility of 4D-flow MRI for a detailed evaluation of AVA.

A novel system for analyzing indocyanine green (ICG) fluorescence spectra enables deeper lung tumor localization during thoracoscopic surgery.

Background: Palpation of tumors during thoracoscopic surgery remains difficult, and identification of deep-seated tumors may be impossible. This preclinical study investigated the usefulness of a novel indocyanine green (ICG) fluorescence spectroscopy system for tumor localization. Methods: ICG was diluted to 5.0×10-2 mg/mL in fetal bovine serum (FBS) and mixed with silicone resin to prepare pseudo-tumors. Sponges of different densities and a porcine lung were placed on top of the pseudo-tumors, which were examined using a novel fluorescence spectroscopy system and a near-infrared (NIR) camera. Spectra were measured for different sponge and lung thicknesses, and the lung spectra were measured during both inflation and deflation. Results: The fluorescence spectroscopy system was able to identify tumors at depths ≥15 mm, while the NIR system was not. The spectroscopy system also detected tumors at greater depths when the density of the intervening material was lower. Depending on the density and thickness of the intervening material, the system could detect spectra as deep as 40 mm for sponges and 30 mm for lungs. Conclusions: This new fluorescence spectroscopy system can be used to identify lung tumors up to a depth of 30 mm in experiments using pseudo-tumors and a porcine lung, which may aid in tumor identification during thoracoscopic surgery.

Development of a minimally invasive pulmonary porcine embolism model via endobronchial ultrasound.

Background: Current massive pulmonary embolism (PE) animal models use central venous access to deliver blood clots, which have features of random clot distribution and potentially fatal hemodynamic compromise. A clinically relevant preclinical model for generating pulmonary emboli in a more controlled fashion would be of value for a variety of research studies, including initial evaluation of novel therapeutic approaches. Endobronchial ultrasound-guided transbronchial needle injection (EBUS-TBNI) is a newly established approach for peri-tracheal/bronchial targets. The purpose of the present work was to establish a minimally invasive PE model in swine via a transbronchial approach. Methods: In anesthetized Yorkshire pigs, a 21-G EBUS-guided transbronchial needle aspiration (EBUS-TBNA) needle was introduced into the pulmonary artery under EBUS guidance. Autologous blood clots were administered into the right and left lower pulmonary arteries sequentially (PE1 and PE2, respectively). Hemodynamic and biochemical responses were evaluated. Results: Ten pigs were evaluated; all 20 blood clots (6.3±1.9 mL) were successfully injected. After injection, mean pulmonary artery pressure (mPAP; mmHg) increased (baseline: 16.6±5.6 vs. PE1: 24.5±7.6, P<0.0001 vs. PE2: 26.9±6.7, P<0.0001), and a positive correlation was observed between clot volume and change in mPAP (PE1: r=0.69, P=0.025; PE1 + PE2: r=0.60, P=0.063). Mean arterial pressure (MAP; mmHg) (baseline: 57.5±5.1 vs. PE1: 59.0±9.1, P=0.918 vs. PE2: 60.9±9.6, P=0.664) remained stable. No complications were observed. Conclusions: EBUS allows minimally invasive, precise, and reliable generation of pulmonary emboli in pigs. This model may serve as an important tool for new PE-related diagnostic and therapeutic research.