Identification of z-axis filopodia in growth cones using super-resolution microscopy.

A growth cone is a highly motile tip of an extending axon that is crucial for neural network formation. Three-dimensional-structured illumination microscopy, a type of super-resolution light microscopy with a resolution that overcomes the optical diffraction limitation (ca. 200 nm) of conventional light microscopy, is well suited for studying the molecular dynamics of intracellular events. Using this technique, we discovered a novel type of filopodia distributed along the z-axis ("z-filopodia") within the growth cone. Z-filopodia were typically oriented in the direction of axon growth, not attached to the substratum, protruded spontaneously without microtubule invasion, and had a lifetime that was considerably shorter than that of conventional filopodia. Z-filopodia formation and dynamics were regulated by actin-regulatory proteins, such as vasodilator-stimulated phosphoprotein, fascin, and cofilin. Chromophore-assisted laser inactivation of cofilin induced the rapid turnover of z-filopodia. An axon guidance receptor, neuropilin-1, was concentrated in z-filopodia and was transported together with them, whereas its ligand, semaphorin-3A, was selectively bound to them. Membrane domains associated with z-filopodia were also specialized and resembled those of lipid rafts, and their behaviors were closely related to those of neuropilin-1. The results suggest that z-filopodia have unique turnover properties, and unlike xy-filopodia, do not function as force-generating structures for axon extension.

Enhanced Thermal Conductivity of Single-Walled Carbon Nanotube with Axial Tensile Strain Enabled by Boron Nitride Nanotube Anchoring.

Thermal conductivity measurements are conducted by optothermal Raman technique before and after the introduction of an axial tensile strain in a suspended single-walled carbon nanotube (SWCNT) through end-anchoring by boron nitride nanotubes (BNNTs). Surprisingly, the axial tensile strain (<0.4 %) in SWCNT results in a considerable enhancement of its thermal conductivity, and the larger the strain, the higher the enhancement. Furthermore, the thermal conductivity reduction with temperature is much alleviated for the strained nanotube compared to previously reported unstrained cases. The thermal conductivity of SWCNT increases with its length is also observed.

Adsorption of Prochiral Solvent Molecules by Surface-Confined Chiral Supramolecular Assemblies: How Solvent Impacts On-Surface Chirality.

The understanding of supramolecular chirality in self-assembled molecular networks (SAMNs) on surfaces generates a lot of interest because of its relation to the production of chiral sensors, reactors, and catalysts. We herein report the adsorption of a prochiral solvent molecule in porous SAMNs formed by a chiral dehydrobenzo[12]annulene (cDBA) derivative. Through the prochirality recognition of a solvent molecule, the supramolecular chirality of the SAMN is switched: the cDBA exclusively forms a counter-clockwise pore through co-adsorption of the solvent molecule in prochiral 1,2,4-trichlorobenzene, while in 1-phenyloctane it produces the opposite chiral, clockwise pore. The prochirality recognition of the solvent molecule in the chiral SAMN pores is attributed to the adaptable conformational changes of the chiral chains of the cDBA molecule.

Automated escape system: identifying prey's kinematic and behavioral features critical for predator evasion.

Identifying the kinematic and behavioral variables of prey that influence evasion from predator attacks remains challenging. To address this challenge, we have developed an automated escape system that responds quickly to an approaching predator and pulls the prey away from the predator rapidly, similar to real prey. Reaction distance, response latency, escape speed and other variables can be adjusted in the system. By repeatedly measuring the response latency and escape speed of the system, we demonstrated the system's ability to exhibit fast and rapid responses while maintaining consistency across successive trials. Using the live predatory fish species Coreoperca kawamebari, we show that escape speed and reaction distance significantly affect the outcome of predator-prey interactions. These findings indicate that the developed escape system is useful for identifying kinematic and behavioral features of prey that are critical for predator evasion, as well as for measuring the performance of predators.

Trastuzumab deruxtecan in patients with human epidermal growth factor receptor 2-expressing salivary gland carcinoma: a pooled analysis of two phase I studies.

BACKGROUND: HER2-expressing salivary gland carcinoma (SGC) is associated with poor prognosis. Trastuzumab deruxtecan (T-DXd, DS-8201) has shown evidence of antitumor activity for several HER2-expressing solid tumors in multiple studies. This study aimed to present the efficacy and safety of T-DXd in patients with HER2-expressing SGC from a pooled analysis. METHODS: Patients with HER2-expressing SGC were pooled from two phase I, open-label studies of T-DXd: a two-phase, multiple-dose, first-in-human study (NCT02564900) and a single-sequence crossover drug-drug interaction study (NCT03383692). Endpoints included efficacy (objective response rate [ORR], duration of response [DoR] and progression-free survival [PFS]) and safety. RESULTS: This pooled analysis included 17 patients with SGC (median age: 57 years; male: 88.2%); median (range) follow-up duration was 12.0 (2.3-|34.8) months. Among these patients, 14 had received prior HER2-targeted agents and 13 had undergone prior radiotherapy. The investigator-assessed confirmed ORR was 58.8% (95% confidence interval [CI], 32.9-|81.6). The median (95% CI) DoR and PFS were 17.6 months (4.0 to not evaluable [NE]) and 20.5 months (11.1-NE), respectively. All 17 patients reported treatment-emergent adverse events (TEAEs); 76.5% reported TEAEs of grade ≥3. The most common TEAEs were decreased appetite (94.1%), nausea (88.2%) and neutrophil count decreased (76.5%). Of the 17 patients, five (29.4%) reported adjudicated drug-related interstitial lung disease (grade 1, n = 3; grade 2, n =1; grade 3, n = 1). CONCLUSION: The results of this pooled analysis provide evidence that clinical benefit is achievable with T-DXd in patients with HER2-expressing SGC. CLINICAL TRIAL INFORMATION: FIH study, NCT02564900; DDI study, NCT03383692.

Trastuzumab deruxtecan in patients with locally advanced or metastatic HER2-positive gastric cancer: a multicenter, open-label, expanded-access study.

BACKGROUND: Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate that consists of an anti-human epidermal growth factor receptor 2 (HER2) antibody bound by a cleavable tetrapeptide-based linker to a cytotoxic topoisomerase I inhibitor. Prior to marketing approval in Japan in September 2020, this expanded-access study was conducted to provide T-DXd to previously treated patients with locally advanced or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinomas. METHODS: This multicenter, open-label, expanded-access study was conducted between March 25 and September 25, 2020 at 17 Japanese sites. Previously treated patients with locally advanced or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinomas received T-DXd 6.4 mg/kg via intravenous infusions at 3-week intervals. Serious adverse events (SAEs), all potential cases of interstitial lung disease (ILD)/pneumonitis, all liver-related events potentially meeting Hy's Law criteria, and all cases of overdose were reported on the case report forms. RESULTS: A total of 64 patients were treated with T-DXd. Among the 17 (26.6%) patients with reported SAEs, 10 (15.6%) had SAEs related to T-DXd treatment. Febrile neutropenia was the most common SAE (n = 6). SAEs led to death in six patients; drug-related SAEs (sepsis and febrile neutropenia) led to death in one patient. Drug-related ILD, as determined by the external Adjudication Committee, occurred in three patients (Grade 1, Grade 2, and Grade 3: all n = 1). CONCLUSION: This expanded-access study provided T-DXd to a broader population of Japanese patients prior to marketing approval in Japan, bridging the gap between clinical trials and drug approval. No new safety concerns were identified.

Successful multidisciplinary treatment for synchronous advanced esophageal and cecal cancers after total gastrectomy with reconstruction by jejunal interposition.

BACKGROUND: Esophageal squamous cell carcinoma is characterized by field cancerization, wherein multiple cancers occur in the esophagus, head and neck, and stomach. Synchronous esophageal and colorectal cancers are also encountered with a certain frequency. A good prognosis can be expected if the tumors in both locations can be safely and completely removed. For patients with multiple cancers that occur simultaneously with esophageal cancer, it is necessary to perform a staged operation, taking into consideration the associated surgical invasiveness. It is also necessary to select multidisciplinary treatment depending on the degree of progression of the multiple lesions. We report our rare experience with a staged operation for a patient with synchronous advanced cancers of the esophagus and cecum who had previously undergone total gastrectomy with reconstruction by jejunal interposition for gastric cancer. CASE PRESENTATION: A 71-year-old man with a history of reconstruction by jejunal interposition after total gastrectomy was diagnosed as having multiple synchronous esophageal and cecal cancers. After neoadjuvant chemotherapy, we performed a planned two-stage operation, with esophagectomy and jejunostomy in the first stage and ileocecal resection and jejunal reconstruction with vascular anastomosis in the second. Postoperatively, the patient was relieved without major complications, and both tumors were amenable to curative pathologic resection. CONCLUSIONS: Our procedure reported here may be recommended as an option for staged resection and reconstruction in patients with simultaneous advanced esophageal and cecal cancer after total gastrectomy.

One-dimensional van der Waals heterostructures: Growth mechanism and handedness correlation revealed by nondestructive TEM.

We recently synthesized one-dimensional (1D) van der Waals heterostructures in which different atomic layers (e.g., boron nitride or molybdenum disulfide) seamlessly wrap around a single-walled carbon nanotube (SWCNT) and form a coaxial, crystalized heteronanotube. The growth process of 1D heterostructure is unconventional-different crystals need to nucleate on a highly curved surface and extend nanotubes shell by shell-so understanding the formation mechanism is of fundamental research interest. In this work, we perform a follow-up and comprehensive study on the structural details and formation mechanism of chemical vapor deposition (CVD)-synthesized 1D heterostructures. Edge structures, nucleation sites, and crystal epitaxial relationships are clearly revealed using transmission electron microscopy (TEM). This is achieved by the direct synthesis of heteronanotubes on a CVD-compatible Si/SiO2 TEM grid, which enabled a transfer-free and nondestructive access to many intrinsic structural details. In particular, we have distinguished different-shaped boron nitride nanotube (BNNT) edges, which are confirmed by electron diffraction at the same location to be strictly associated with its own chiral angle and polarity. We also demonstrate the importance of surface cleanness and isolation for the formation of perfect 1D heterostructures. Furthermore, we elucidate the handedness correlation between the SWCNT template and BNNT crystals. This work not only provides an in-depth understanding of this 1D heterostructure material group but also, in a more general perspective, serves as an interesting investigation on crystal growth on highly curved (radius of a couple of nanometers) atomic substrates.

Technical outcomes of robotic-assisted surgery versus laparoscopic surgery for rectal tumors: a single-center safety and feasibility study.

PURPOSE: Robot-assisted surgery has a multi-joint function, which improves manipulation of the deep pelvic region and contributes significantly to perioperative safety. However, the superiority of robot-assisted surgery to laparoscopic surgery remains controversial. This study compared the short-term outcomes of laparoscopic and robot-assisted surgery for rectal tumors. METHODS: This single-center, retrospective study included 273 patients with rectal tumors who underwent surgery with anastomosis between 2017 and 2021. In total, 169 patients underwent laparoscopic surgery (Lap group), and 104 underwent robot-assisted surgery (Robot group). Postoperative complications were compared via propensity score matching based on inverse probability of treatment weighting (IPTW). RESULTS: The postoperative complication rates based on the Clavien-Dindo classification (Lap vs. Robot group) were as follows: grade ≥ II, 29.0% vs. 19.2%; grade ≥ III, 10.7% vs. 5.8%; anastomotic leakage (AL), 6.5% vs. 4.8%; and urinary dysfunction (UD), 12.1% vs. 3.8%. After adjusting for the IPTW method, although AL rates did not differ significantly between groups, postoperative complications of both grade ≥ II (odds ratio [OR] 0.66, 95% confidence interval [CI] 0.50-0.87, p < 0.01) and grade ≥ III (OR 0.29, 95% CI 0.16-0.53, p < 0.01) were significantly less frequent in the Robot group than in the Lap group. Furthermore, urinary dysfunction also tended to be less frequent in the Robot group than in the Lap group (OR 0.62, 95% CI 0.38-1.00; p = 0.05). CONCLUSION: Robot-assisted surgery for rectal tumors provides better short-term outcomes than laparoscopic surgery, supporting its use as a safer approach.

Impact of computer-aided characterization for diagnosis of colorectal lesions, including sessile serrated lesions: Multireader, multicase study.

OBJECTIVES: Computer-aided characterization (CADx) may be used to implement optical biopsy strategies into colonoscopy practice; however, its impact on endoscopic diagnosis remains unknown. We aimed to evaluate the additional diagnostic value of CADx when used by endoscopists for assessing colorectal polyps. METHODS: This was a single-center, multicase, multireader, image-reading study using randomly extracted images of pathologically confirmed polyps resected between July 2021 and January 2022. Approved CADx that could predict two-tier classification (neoplastic or nonneoplastic) by analyzing narrow-band images of the polyps was used to obtain a CADx diagnosis. Participating endoscopists determined if the polyps were neoplastic or not and noted their confidence level using a computer-based, image-reading test. The test was conducted twice with a 4-week interval: the first test was conducted without CADx prediction and the second test with CADx prediction. Diagnostic performances for neoplasms were calculated using the pathological diagnosis as reference and performances with and without CADx prediction were compared. RESULTS: Five hundred polyps were randomly extracted from 385 patients and diagnosed by 14 endoscopists (including seven experts). The sensitivity for neoplasia was significantly improved by referring to CADx (89.4% vs. 95.6%). CADx also had incremental effects on the negative predictive value (69.3% vs. 84.3%), overall accuracy (87.2% vs. 91.8%), and high-confidence diagnosis rate (77.4% vs. 85.8%). However, there was no significant difference in specificity (80.1% vs. 78.9%). CONCLUSIONS: Computer-aided characterization has added diagnostic value for differentiating colorectal neoplasms and may improve the high-confidence diagnosis rate.

Cytoskeletal fractionation identifies LMO7 as a positive regulator of fibroblast polarization and directed migration.

Cell migration is a cytoskeleton-driven cellular process involved in physiological and pathological events such as embryonic development and cancer metastasis. Fibroblasts have often been used to elucidate the mechanism of cell migration due to their high morphological polarity and migratory activity. We recently reported that human lung fibroblasts migrate straight for a long duration without external stimuli, which phenomenon we named intrinsic and directed migration (IDM) of fibroblasts. In this study, we explored proteins involved in IDM in order to elucidate the molecular mechanism. First, we focused on the differences in morphology and migratory behaviors between normal and immortalized fibroblasts-the former exhibit obvious polarity and IDM; the latter exhibit poorly polarized morphology and random migration. We compared the abundance of proteins functioning as the cytoskeletal components between them through proteomic analysis and found that LIM domain only protein 7 (LMO7) is overwhelmingly incorporated into the cytoskeletons of normal fibroblasts. Depletion of LMO7 inhibited the directed migration of normal fibroblast on the fibronectin (FN)-rich surface, suggesting that LMO7 is important for IDM. Moreover, on the FN-free surface, LMO7-depleted fibroblasts often failed to establish morphological polarity and hardly migrated. Thus, the present study identified LMO7 as a positive regulator of fibroblast polarization and IDM, especially in an environment where integrin-mediated substrate attachment is insufficient.

Formation of Supramolecular Heterostacks at the Liquid-Solid Interface: Impact of Symmetry Mismatching on Structural Growth.

The construction of intricate three-dimensional (3D) nanoarchitectures on surfaces through molecular self-assembly attracts attention not only from a crystal engineering viewpoint but also because of its potential in a range of applications, given the current interest in van der Waals heterostructures. We herein report the formation of porous structures on alkane buffer layers on graphite. A dehydrobenzo[12]annulene (DBA) derivative having six decyloxy chains forms hexagonal structures on n-pentacontane and n-hexacontane buffer layers through van der Waals interactions at the 1-octanoic acid/graphite interface. The structural features are very similar to those on the graphite surface, except for the slight structural distortion, which is attributed to the p2 symmetry of the buffer layer underneath. Moreover, based on the observation of small clusters of the DBA molecules, we discussed the nucleation and structural growth of the DBA network on a buffer layer. Finally, a hierarchical multicomponent structure was formed through the coadsorption of a heteromolecular cluster formed by a hydrogen-bonded isophthalic acid cyclic hexamer hosting a coronene molecule on the buffer layer. This study on supramolecular heterostacks provides insights into the construction of intricate 3D nanoarchitectures using self-assembly at interfaces.

Perioperative predictive factors of failure to rescue following highly advanced hepatobiliary-pancreatic surgery: a single-institution retrospective study.

BACKGROUND: Failure to rescue (FTR), defined as a postoperative complication leading to death, is a recently described outcome metric used to evaluate treatment quality. However, the predictive factors for FTR, particularly following highly advanced hepatobiliary-pancreatic surgery (HBPS), have not been adequately investigated. This study aimed to identify perioperative predictive factors for FTR following highly advanced HBPS. METHODS: This single-institution retrospective study involved 177 patients at Gifu University Hospital, Japan, who developed severe postoperative complications (Clavien-Dindo classification grades ≥ III) between 2010 and 2022 following highly advanced HBPS. Univariate analysis was used to identify pre-, intra-, and postoperative risks of FTR. RESULTS: Nine postoperative mortalities occurred during the study period (overall mortality rate, 1.3% [9/686]; FTR rate, 5.1% [9/177]). Univariate analysis indicated that comorbid liver disease, intraoperative blood loss, intraoperative blood transfusion, postoperative liver failure, postoperative respiratory failure, and postoperative bleeding significantly correlated with FTR. CONCLUSIONS: FTR was found to be associated with perioperative factors. Well-coordinated surgical procedures to avoid intra- and postoperative bleeding and unnecessary blood transfusions, as well as postoperative team management with attention to the occurrence of organ failure, may decrease FTR rates.

Drain fluid and serum amylase concentration ratio is the most reliable indicator for predicting postoperative pancreatic fistula after distal pancreatectomy.

BACKGROUND: Postoperative pancreatic fistula (POPF) is a major complication of pancreatic surgery. Drain fluid amylase concentration (DAC) is considered a predictive indicator of POPF. However, other indicators related to postoperative drain fluid amylase status exist, and the most reliable indicator for predicting POPF remains unclear. The object of this study is to identify the single most accurate indicator related to drain fluid amylase status of POPF after distal pancreatectomy (DP). METHODS: This single-institution retrospective study included 122 patients who underwent DP. The study was conducted between 2010 and 2022 at Gifu University Hospital. We statistically analyzed DAC, drain fluid amylase amount (DAA) calculated by multiplying DAC and daily drainage volume, and drain and serum amylase concentration ratio (DSACR) to assess the correlation with POPF. RESULTS: Based on the definition and grading of the International Study Group of Pancreatic Fistula, 24.6 (%) of the 122 patients had Grades B and C POPF. The result of the receiver operating characteristic (ROC) curve for predicting POPF after DP, DSACR had the highest area under curve(AUC) value among DAC, DAA, and DSACR both POD1 and POD3. The cutoff value of DSACR on POD1 was 17 (AUC 0.69, sensitivity 80.0%, specificity 58.2%, and accuracy 63.6%). The cutoff value of DSACR on POD3 was 22 (AUC 0.77, sensitivity 77.7%, specificity 73.3%, and accuracy 73.6%). Overall, DSACR on POD3 had the highest AUC value. Furthermore, a multivariate logistic regression analysis revealed that pancreatic texture (soft; odds ratio [OR] 9.22; 95% confidence interval [CI] 2.22-44.19; p < 0.01) and DSACR on POD3 (> 22; OR 8.76; 95% CI 2.78-31.59; p < 0.001) were independently associated with POPF after DP. CONCLUSIONS: DSACR is the most reliable indicator of drain fluid amylase status for predicting POPF after DP.

Short-term outcomes associated with the use of a new powered circular stapler for rectal reconstructions: a retrospective study comparing it to manual circular staplers using inverse probability of treatment weight analysis.

BACKGROUND: The most common postoperative complication in malignant rectal surgery is anastomotic leakage (AL). AL after anterior or low anterior resection in rectal tumors is a fatal postoperative complication. Recently, the first automated suture circular stapler, which is expected to reduce the incidence of AL, (J&J). MATERIALS AND METHODS: This study included a total of 248 rectal tumor patients who underwent double stapler technique (DST) anastomotic procedures in the department of gastroenterological surgery /pediatric surgery at Gifu University School of Medicine from January 2017 to December 2021. The experience of a single institution utilizing the The Echelon circular™ stapler (ECP stapler:Manual VS Automatic) in rectal surgery cases was evaluated retrospectively from maintained database. RESULT: One hundred thirty-nine patients (58.4%) were performed by manual circular stapling, 99 patients (41.6%) by powerd circular stapling. Diverting stoma was performed in 45 cases (32.4%) by manual circular stapling, 42 patients (42.4%) by powerd circular stapling Postoperative complications were occurred clavien-dindo grade II or higher in 57 cases (23.9%) and grade III or higher in 20 cases (8.4%). Anastomotic leakage occurred in 14 patients (5.9%) within all grades. After IPTW, the variables of patient characteristics was SMD ≤ 0.2 (Table.3), and there was a significant difference in anastomotic leakage (Odds Ratio (OR), 0.57; 95% Confidence Interval(CI), 0.34-0.98; p = 0.041). In addition, there was no significant difference in postoperative complications in grade II or higher (OR, 0.88; 95%CI, 0.65-1.19; p = 0.417) and grade III or higher (OR, 0.46; 95%CI, 0.29-0.74; p = 0.001) were significantly remarkable lower in powered circular stapling group. CONCLUSION: In this IPTW comparison of patients undergoing rectal reconstructions, the ECP trial cohort had lower risks of several surgical complications AL and statistically signifcant lower rates of ileus/bowel obstruction, infection, and bleeding as Clavien-Dindo ≥ grade II and III as compared with for whom manual circular staplers were used.

Photo/Electrocatalytic Hydrogen Peroxide Production by Manganese and Iron Porphyrin/Molybdenum Disulfide Nanoensembles.

The oxygen reduction reaction (ORR) 2e- pathway provides an alternative and green route for industrial hydrogen peroxide (H2 O2 ) production. Herein, the ORR photo/electrocatalytic activity in the alkaline electrolyte of manganese and iron porphyrin (MnP and FeP, respectively) electrostatically associated with modified 1T/2H MoS2 nanosheets is reported. The best performing catalyst, MnP/MoS2 , exhibits excellent electrocatalytic performance towards selective H2 O2 formation, with a low overpotential of 20 mV for the 2e- ORR pathway (Eons  = 680 mV vs RHE) and an H2 O2 yield up to 99%. Upon visible light irradiation, MnP/MoS2 catalyst shows significant activity enhancement along with good stability. Electrochemical impedance spectroscopy assays suggest a reduced charge transfer resistance value at the interface with the electrolyte, indicating an efficient intra-ensemble transfer process of the photo-excited electrons through the formation of a type II heterojunction or Schottky contact, and therefore justifies the boosted electrochemical activities in the presence of light. Overall, this work is expected to inspire the design of novel advanced photo/electrocatalysts, paving the way for sustainable industrial H2 O2 production.

Serum diamine oxidase activity derived from response to chemotherapy affects adverse events and serum amino acid levels.

PURPOSE: The relationship between activity of the small intestinal villi and the effectiveness of chemotherapy remains unclear. This study aimed to investigate how serum diamine oxidase (DAO) activity affects antitumor effects, adverse events, and amino acid absorption. METHODS: We performed a single-center prospective cohort study that enrolled 50 patients with esophageal cancer (EC) receiving docetaxel, cisplatin, and 5-fluorouracil therapy. We determined the cut-off value of serum DAO activity contributing to a response to chemotherapy using a generalized additive model. Additionally, we compared adverse events, inflammatory markers, blood amino acid levels, and quality of life between the high and low DAO activity groups during chemotherapy. RESULTS: The cut-off value of serum DAO activity at the first visit that contributed to a chemotherapy response was 6.5 units/L. Leukopenia and neutropenia of grade ≥ 3 were significantly higher in the DAO low (< 6.5 units/L) group (p = 0.044, 0.017, respectively). Interleukin-6 was significantly lower in the DAO high (≥ 6.5 units/L) group at the first visit and at 4 weeks after the end of chemotherapy (p = 0.039, 0.011, respectively). Glutamine was higher in the DAO high group at all measurement points during chemotherapy. Fatigue was significantly lower in the DAO high group (p = 0.001). CONCLUSION: Serum DAO activity may be a predictor of the response to chemotherapy in patients with EC. The absorption capacity of amino acids was maintained in the group with high DAO activity, which may have contributed to the anti-inflammatory effect and provided a background for reducing adverse events.

Right top pulmonary vein is a venous anomaly of which surgeons should be aware in subcarinal dissection for thoracoscopic esophagectomy: a case report and literature review.

BACKGROUND: A right top pulmonary vein (RTPV) that crosses behind the right main or intermediate bronchus is a variation of the superior posterior pulmonary vein in the right upper lobe. Damage or ligation of this abnormal vessel can lead to massive intraoperative bleeding and serious complications, such as congestion of the posterior segment of the right upper lobe and cardiac tamponade. Subcarinal lymph node dissection is mandatory in radical thoracoscopic esophagectomy for esophageal cancer, and the RTPV is an anomalous vessel of which thoracic surgeons should be aware. CASE PRESENTATION: A 70-year-old man underwent thoracoscopic esophagectomy for esophageal cancer (T3N1M0). An anomaly of the superior posterior pulmonary vein in the right lobe was recognized on preoperative computed tomography imaging. With simulation and intraoperative navigation using three-dimensional imaging of the same view as that observed during the operation, radical subcarinal dissection could be performed with preservation of the RTPV. CONCLUSION: In our review of the relevant literature, the incidence of RTPV ranged from 0.28 to 9.3%, and its mean vascular diameter was 7.0 mm at the maximum and 2.2 ± 0.72 mm at the minimum, with the right superior pulmonary vein being a relatively common inflow site. Our case in which the RTPV ran dorsal to the right main bronchus is very rare. In radical subcarinal dissection of thoracoscopic esophagectomy, it is important to recognize the posterior pericardial plane and release the ventral fixation of these lymph nodes to free space for the back side. This is also true in the case of RTPV, which should be noted to avoid injury. In cases involving an RTPV larger than 4.5 mm, ligation should be avoided, and preoperative recognition of the exact run of this abnormal vessel using three-dimensional imaging can be very useful.

Total laparoscopic resection by medial-retroperitoneal approach using virtual navigation: two case reports of primary retroperitoneal schwannoma.

BACKGROUND: We report two rare cases of retroperitoneal schwannoma completely resected by a laparoscopic medial-retroperitoneal approach aided by virtual navigation. Three-dimensional images have been used in liver and lung surgery, but there are few prior reports on retroperitoneal surgery. CASE PRESENTATION: These two case reports are of a 60-year-old man and a 40-year-old man with asymptomatic retroperitoneal schwannoma. In both cases, the tumors were located in the right renal hilum and were close to the duodenum, right ureter, and inferior vena cava. Simulation using three-dimensional images was performed before surgery, and a medial-retroperitoneal approach was performed to secure a wide surgical field. During the operation, we confirmed the location of the main feeder and the relationship between the tumor and organs with those shown on the three-dimensional images and performed total laparoscopic resection. CONCLUSION: The medial-retroperitoneal approach provides operative safety. Preoperative simulation and intraoperative navigation with three-dimensional images, which can be freely rotated and interactively visualized from any angle, are useful methods to enhance the surgeon's understanding of a patient's specific anatomy and are especially effective when resecting a retroperitoneal tumor that is located in an anatomically deep and complex location.

The pancreas-to-muscle signal intensity ratio on T1-weighted MRI as a predictive biomarker for postoperative pancreatic fistula after distal pancreatectomy: a single-center retrospective study.

BACKGROUND: Postoperative pancreatic fistula (POPF) is one of the serious complications of pancreatic surgery. When POPF occurs and becomes severe, it causes secondary complications and a longer treatment period. We previously reported a correlation between pancreatic fibrosis and magnetic resonance imaging (MRI) findings, and MRI may have the potential to predict POPF. This study aimed to assess the predictive ability of the pancreas-to-muscle signal intensity ratio on T1-weighted MRI (SIR on T1-w MRI) for POPF after distal pancreatectomy (DP). METHODS: This single-institution retrospective study comprised 117 patients who underwent DP. It was conducted between 2010 and 2021 at the Gifu University Hospital. We statistically analyzed pre-, intra-, and postoperative factors to assess the correlation with POPF. RESULTS: According to the definition and grading of the International Study Group of Pancreatic Fistula (ISGPF), 29 (24.8%) of the 117 patients had POPF grades B and C. In the univariate analysis, POPF was significantly associated with the pancreas-to-muscle SIR on T1-w MRI, the drainage fluid amylase concentration (D-Amy) levels on postoperative day (POD) 1 and 3, white blood cell count on POD 1 and 3, C-reactive protein level on POD 3, and heart rate on POD 3. In multivariate analysis, only the pancreas-to-muscle SIR on T1-w MRI (>1.37; odds ratio [OR] 23.25; 95% confidence interval [CI] 3.93-454.03; p < 0.01) and D-Amy level on POD 3 (>737 U/l; OR 3.91; 95% CI 1.02-16.36; p = 0.046) were identified as independent predictive factors. CONCLUSIONS: The pancreas-to-muscle SIR on T1-w MRI and postoperative D-Amy levels were able to predict the development of POPF after DP. The pancreas-to-muscle SIR on T1-w MRI may be a potential objective biomarker reflecting pancreatic status.