An Elemental Diet Reduces Chylous Ascites of Patients Undergoing Pancreatoduodenectomy in the Setting of Early Enteral Feeding.

OBJECTIVES: The elemental diet (ED) is a formula to support nutritional status without increasing chylous burden. This study evaluates the efficacy of early ED feeding after pancreatoduodenectomy (PD). MATERIALS AND METHODS: A prospective phase II study of consecutive patients who underwent PD with early ED feeding was conducted. Patient backgrounds, surgical outcomes, and ED feeding tolerability were compared with a historical cohort of 74 PD patients with early enteral feeding of a low residue diet (LRD). RESULTS: The ED group comprised 104 patients. No patient in the ED group discontinued enteral feeding because of chylous ascites (CAs), whereas 17.6% of the LRD group experienced refractory CAs that disrupted further enteral feeding. The CAs rate was significantly decreased in the ED group compared with the LRD group (3.9% and 48.7%, respectively; P < 0.001). There was no significant difference in the incidence of major complications (ED: 17.3%, LRD: 18.9%; P = 0.844). Postoperative prognostic nutritional index was similar between the 2 groups ( P = 0.764). In multivariate analysis, enteral feeding formula, and sex were independent risk factors for CAs (LRD: P < 0.001, odds ratio, 22.87; female: P = 0.019, odds ratio, 2.78). CONCLUSIONS: An ED reduces postoperative CAs of patients undergoing PD in the setting of early enteral feeding.

Artificial Intelligence-Guided Segmentation and Path Planning Software for Transthoracic Lung Biopsy.

PURPOSE: To validate the sensitivity and specificity of a 3-dimensional (3D) convolutional neural network (CNN) artificial intelligence (AI) software for lung lesion detection and to establish concordance between AI-generated needle paths and those used in actual biopsy procedures. MATERIALS AND METHODS: This was a retrospective study using computed tomography (CT) scans from 3 hospitals. Inclusion criteria were scans with 1-5 nodules of diameter ≥5 mm; exclusion criteria were poor-quality scans or those with nodules measuring <5mm in diameter. In the lesion detection phase, 2,147 nodules from 219 scans were used to develop and train the deep learning 3D-CNN to detect lesions. The 3D-CNN was validated with 235 scans (354 lesions) for sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) analysis. In the path planning phase, Bayesian optimization was used to propose possible needle trajectories for lesion biopsy while avoiding vital structures. Software-proposed needle trajectories were compared with actual biopsy path trajectories from intraprocedural CT scans in 150 patients, with a match defined as an angular deviation of <5° between the 2 trajectories. RESULTS: The model achieved an overall AUC of 97.4% (95% CI, 96.3%-98.2%) for lesion detection, with mean sensitivity of 93.5% and mean specificity of 93.2%. Among the software-proposed needle trajectories, 85.3% were feasible, with 82% matching actual paths and similar performance between supine and prone/oblique patient orientations (P = .311). The mean angular deviation between matching trajectories was 2.30° (SD ± 1.22); the mean path deviation was 2.94 mm (SD ± 1.60). CONCLUSIONS: Segmentation, lesion detection, and path planning for CT-guided lung biopsy using an AI-guided software showed promising results. Future integration with automated robotic systems may pave the way toward fully automated biopsy procedures.

Management of potential portal vein thrombus during laparoscopic right hemihepatectomy following portal vein embolization.

BACKGROUND: Portal vein embolization (PVE) is often performed prior to right hemihepatectomy (RH) to increase the future liver remnants. However, intraoperative removal of portal vein thrombus (PVT) is occasionally required. An algorithm for treating the right branch of the PV using laparoscopic RH (LRH) after PVE is lacking and requires further investigation. METHODS: In our department, after the confirmation of a lack of extension of PVT to the main portal trunk or left branch on preoperative examination (ultrasound and contrast-enhanced computed tomography), a final evaluation was performed using intraoperative ultrasonography (IOUS). Here we present the cases of eight patients who underwent LRH after PVE and examine the safety of our treatment strategies. RESULTS: IOUS revealed PVT extension into the main portal trunk in two cases. For the other six patients without PVT extension, we continued the laparoscopic procedure. In contrast, in the two cases with PVT extension, we converted to laparotomy after hepatic transection and removed the PVT. The median operation time for hepatectomy was 562 min (421-659 min), the median blood loss was 293 mL (85-1010 mL), no liver-related postoperative complications were observed, and the median length of stay was 10 days (6-34 days). CONCLUSIONS: PVT evaluation and removal are important in cases of LRH after PVE. Our strategy is safe and IOUS is particularly useful for laparoscopically evaluating PVT extension.

Laparoscopic Portal Vein Ligation and Embolization During First-Stage Hepatectomy for Initially Unresectable Colorectal Liver Metastases.

BACKGROUND: Two-stage hepatectomy (TSH) is the only treatment for the patients with multiple bilobar colorectal liver metastases (CRMs) who are not candidates for one-step hepatectomy because of insufficient future remnant liver volume and/or impaired liver function.1-5 Although laparoscopic approaches have been introduced for TSH,6-8 the postoperative morbidity and mortality remains high because of the technical difficulties during second-stage hepatectomy.9,10 The authors present a video of laparoscopic TSH with portal vein (PV) ligation and embolization, which minimizes adhesions and PV thrombosis risk in the remnant liver, thereby facilitating second-stage hepatectomy. METHODS: Three patients with initially unresectable bilateral CRMs received a median of chemotherapy 12 cycles, followed by conversion TSH. After right PV ligation, laproscopic PV embolization was performed by injection of 100% ethanol into the hepatic side of the right PV using a 23-gauge winged needle. After PV embolization, a spray adhesion barrier (AdSpray, Terumo, Tokyo, Japan)11 was applied. RESULTS: During the first stage of hepatectomy, two patients underwent simultaneous laparoscopic colorectal resection (left hemicolectomy and high anterior resection). In the initial hepatectomy, two patients underwent two limited hepatectomies each, and one patient underwent six hepatectomies in the left lobe. After hepatectomy, all the patients underwent right PV embolization. During the second stage, two patients underwent open extended right hepatectomy (right adrenalectomy was performed because of adrenal invasion in one patient), and one patient underwent laparoscopic extended right hepatectomy. No postoperative complications occurred in the six surgeries. CONCLUSIONS: Laparoscopic TSH with PV embolization is recommended for safe completion of the second hepatectomy.

Ongoing EEG artifact correction using blind source separation.

OBJECTIVE: Analysis of the electroencephalogram (EEG) for epileptic spike and seizure detection or brain-computer interfaces can be severely hampered by the presence of artifacts. The aim of this study is to describe and evaluate a fast automatic algorithm for ongoing correction of artifacts in continuous EEG recordings, which can be applied offline and online. METHODS: The automatic algorithm for ongoing correction of artifacts is based on fast blind source separation. It uses a sliding window technique with overlapping epochs and features in the spatial, temporal and frequency domain to detect and correct ocular, cardiac, muscle and powerline artifacts. RESULTS: The approach was validated in an independent evaluation study on publicly available continuous EEG data with 2035 marked artifacts. Validation confirmed that 88% of the artifacts could be removed successfully (ocular: 81%, cardiac: 84%, muscle: 98%, powerline: 100%). It outperformed state-of-the-art algorithms both in terms of artifact reduction rates and computation time. CONCLUSIONS: Fast ongoing artifact correction successfully removed a good proportion of artifacts, while preserving most of the EEG signals. SIGNIFICANCE: The presented algorithm may be useful for ongoing correction of artifacts, e.g., in online systems for epileptic spike and seizure detection or brain-computer interfaces.

Technical Strategy for Pancreatic Body Cancers: A Raison d'etre of Distal Pancreatectomy with Portal Resection.

BACKGROUND: Advancements in multiagent chemotherapy have expanded the surgical indications for pancreatic cancer. Although pancreaticoduodenectomy (PD) with portal vein resection (PVR) has become widely adopted, distal pancreatectomy (DP) with PVR remains rarely performed because of its technical complexity. This study was designed to assess the feasibility of DP-PVR compared with PD-PVR for pancreatic body cancers, with a focus on PV complications and providing optimal reconstruction techniques when DP-PVR is necessary. METHODS: A retrospective review was conducted on consecutive pancreatic body cancer patients who underwent pancreatectomy with PVR between 2005 and 2020. An algorithm based on the anatomical relationship between the arteries and PV was used for optimal surgical selection. RESULTS: Among 119 patients, 32 underwent DP-PVR and 87 underwent PD-PVR. Various reconstruction techniques were employed in DP-PVR cases, including patch reconstruction, graft interposition, and wedge resection. The majority of PD-PVR cases involved end-to-end anastomosis. The length of PVR was shorter in DP-PVR (25 vs. 40 mm; p < 0.001). Although Clavien-Dindo ≥3a was higher in DP-PVR (p = 0.002), inpatient mortality and R0 status were similar. Complete PV occlusion occurred more frequently in DP-PVR than in PD-PVR (21.9% vs. 1.1%; p < 0.001). A cutoff value of 30 mm for PVR length was determined to be predictive of nonrecurrence-related PV occlusion after DP-PVR. The two groups did not differ significantly in recurrence or overall survival. CONCLUSIONS: DP-PVR had higher occlusion and postoperative complication rates than PD-PVR. These findings support the proposed algorithm and emphasize the importance of meticulous surgical manipulation when DP-PVR is deemed necessary.

Neoadjuvant chemotherapy for borderline resectable colorectal cancer liver metastases: a single-institution retrospective study.

INTRODUCTION: This study aimed to extract prognostic factors in patients undergoing neoadjuvant chemotherapy (NAC) for borderline resectable colorectal liver metastasis (BR-CRLM) (tumor size ≥5 cm, number of tumors ≥4, or resectable extrahepatic diseases) and assess validity of this strategy. MATERIALS AND METHODS: Since 2010, patients with BR-CRLM were treated with hepatectomy after six cycles of NAC. Prognostic factors of these patients were evaluated using clinicopathological data. RESULTS: Of 650 patients who underwent initial hepatectomy for CRLM from 2010 to 2018, 246 BR-CRLM cases underwent hepatectomy after NAC (BR-NAC). The 5-year recurrence-free survival rate was 16.7% and the 5-year overall survival rate (5y-OS) was 52.9%. Number of tumors ≥6, carcinoembryonic antigen (CEA) level ≥25 ng/mL, tumor diameter ≥5 cm, and progressive disease (PD) after NAC were identified as independent poor prognostic factors for OS. Patients were divided into four groups according to the number of risk factors, and prognoses of the four groups were well stratified. CONCLUSION: In patients with BR-NAC, number of tumors ≥6, CEA ≥25 ng/mL, tumor diameter ≥5 cm, and PD after NAC were independent poor prognostic factors. Patients with three or four risk factors showed poor prognosis and may need to switch chemotherapy.

Unique Biology of Pancreatic Ductal Adenocarcinoma Accompanied by Rapidly Impaired Diabetes: A Favorable Long-Term Survival Following Curative Resection.

BACKGROUND: Pancreatic ductal adenocarcinomas (PDACs) are sometimes diagnosed accompanied by rapidly impaired diabetes (PDAC-RID). Although this type of PDAC may have unusual biological features, these features have not been explained. METHODS: Patients with PDAC who underwent upfront pancreatectomy between 2010 and 2018 were retrospectively reviewed. PDAC-RID was defined as a glycated hemoglobin (HbA1c) value of ≥ 8.0% of newly diagnosed diabetes, and acute exacerbation of previously diagnosed diabetes. Other patients were classified as PDAC with stable glycometabolism (PDAC-SG). Clinicopathological factors, long-term survival rates, and recurrence patterns were evaluated. RESULTS: Of the 520 enrolled patients, 104 were classified as PDAC-RID and 416 as PDAC-SG. There was no significant difference regarding TNM staging, resectability, or adjuvant chemotherapy rate between the groups. However, 5-years cancer-specific survival (CSS) was significantly higher in the PDAC-RID group than in the PDAC-SG group (45.3% vs. 31.1%; p = 0.02). This survival difference was highlighted in relatively early-stage PDAC (≤ pT2N1) (CSS: 60.8% vs. 43.6%; p = 0.01), but the difference was not significant for advanced-stage PDAC. A multivariate analysis of early-stage PDAC showed that PDAC-SG was an independent risk factor of shorter CSS (hazard ratio 1.76; p = 0.02). The hematogenous metastatic rate in early-stage PDAC was lower in the PDAC-RID group than in the PDAC-SG group (18.3% vs. 35.8%; p = 0.01). CONCLUSIONS: PDAC-RID showed a favorable long-term survival rate after curative resection with low hematogenous metastases, which may be due to its unique biology.

Electron holography observation of electron spin polarization around charged insulating wire.

We report direct observation by electron holography of the spin polarization of electrons in a vacuum region around a charged SiO2 wire coated with Pt-Pd. Irradiating the SiO2 wire with 300-keV electrons caused the wire to become positively charged due to the emission of secondary electrons. The spin polarization of these electrons interacting with the charged wire was observed in situ using a phase reconstruction process under an external magnetic field. The magnetic field of the spin-polarized electrons was simulated taking into account the distribution of secondary electrons and the effect of the external magnetic field.

New approach of circumferential lymph node dissection around the superior mesenteric artery for pancreatic cancer during pancreaticoduodenectomy (with video).

PURPOSE: Various approaches have been reported for the resection of the nervous and lymphatic tissues around the superior mesenteric artery (SMA) during pancreaticoduodenectomy (PD) for pancreatic cancer. We developed a new procedure for circumferential lymph node dissection around the SMA to minimize local recurrence. METHODS: We included 24 patients who underwent PD with circumferential lymph node dissection around the SMA (circumferential dissection) and 94 patients who underwent classical mesopancreatic dissection (classical dissection) between 2019 and 2021. The technical details of this new method are described in the figures and videos, and the clinical characteristics and outcomes of this technique were compared with those of classical dissection. RESULTS: The median follow-up durations in the circumferential and classical dissection groups were 39 and 36 months, respectively. The patients' characteristics, including tumor resectability, preoperative and adjuvant chemotherapy rates, postoperative complication rates, and tumor stage, were similar between the two groups. No differences were observed in recurrence-free survival and overall survival between the two groups; however, the classical dissection group tended to have more local recurrences than the circumferential dissection group (8.3% vs. 33.3%, P = 0.168). Although no case of nodular-type recurrence after circumferential dissection was observed, 61.1% of local recurrences after classical dissection were of the nodular-type, and 36.4% were located on the left side of the SMA. CONCLUSIONS: Performing circumferential lymph node dissection around the SMA during PD can be conducted safely with minimal risks of local recurrence and may enhance the completeness of local resection.

Moiré-Assisted Realization of Octahedral MoTe2 Monolayer.

A current key challenge in 2D materials is the realization of emergent quantum phenomena in hetero structures via controlling the moiré potential created by the periodicity mismatch between adjacent layers, as highlighted by the discovery of superconductivity in twisted bilayer graphene. Generally, the lattice structure of the original host material remains unchanged even after the moiré superlattice is formed. However, much less attention is paid for the possibility that the moiré potential can also modify the original crystal structure itself. Here, it is demonstrated that octahedral MoTe2 which is unstable in bulk is stabilized in a commensurate MoTe2 /graphene hetero-bilayer due to the moiré potential created between the two layers. It is found that the reconstruction of electronic states via the moiré potential is responsible for this stabilization, as evidenced by the energy-gap opening at the Fermi level observed by angle-resolved photoemission and scanning tunneling spectroscopies. The present results provide a fresh approach to realize novel 2D quantum phases by utilizing the moiré potential.

Laparoscopic dissection around the superior mesenteric artery by left posterior approach during pancreaticoduodenectomy.

BACKGROUND: In pancreaticoduodenectomy (PD), the approach to superior mesenteric artery (SMA) is a critical process that supports adequate surgical margins and radicality for pancreatic tumors. In most of the reports on laparoscopic PD, the right-sided approach in which the jejunum is pulled out to the right side for peri-SMA dissection is used, since the left side of the SMA is difficult to dissect, and the only way to do this is to dissect the vein first. METHODS: We devised a method to simplify and safely perform peri-SMA dissection by reversing the process, starting from the left side of the SMA. The first step involves the mobilization of the pancreatic head, which allows for rotation around the SMA. The second step involves the dissection of the left side of the SMA and transection of the jejunum. The key point is to change the incision line between the anterior and posterior mesojejunum. The third process includes the inferior pancreatoduodenal artery (IPDA) and first jejunal artery (J1A) dissection, which can be easily performed from the left side because the SMA rotates by simply continuing the dissection along the previously exposed SMA, and the IPDA/J1A are safely dissected at the root because they are drawn to the left side. The remaining processes are performed on the right side. RESULTS: This method was performed in 16 cases, and in most cases IPDA/J1A were divided from the left side. CONCLUSION: The technique for SMA dissection from the left posterior side was described with illustrations and video. Our method allows safe oncologic dissection around SMA avoiding anatomical misorientation during laparoscopic PD.

Robotic Splenic Vessels Preserving Distal Pancreatectomy in a Post-Distal Gastrectomy Patient.

BACKGROUND: The optimal procedure during distal pancreatectomy (DP) for patients who have undergone distal gastrectomy (DG) remains unclear. Several papers on remnant gastric ischemia have reported that the preserved splenic vessels are essential for the proximal remnant stomach.1-4 We evaluated the outcomes of DP for post-DG patients in our hospital and introduced robotic splenic vessels preserving DP (R-SPDP). METHODS: Postoperative short-term outcomes of DP for post-DG patients during 2014 and 2021 were evaluated. Next, R-SPDP was performed for a post-DG patient with the intention of preserving the remnant stomach safely. The double bipolar method was used to dissect the adhesions around the splenic vessels.5,6 The splenic artery was clamped at the root side to prevent bleeding.7 All short gastric arteries and veins, which were the main feeders of the remnant stomach, were preserved and resection was completed. After resection, the indocyanine green (ICG) fluorescence angiography confirmed blood flow in the short gastric arteries and veins and good return blood flow to the splenic vein.8 RESULTS: Of four patients (50.0%, of 8 DP patients) in whom the remnant stomach was preserved, one conventional DP case had poor ICG perfusion and presented with remnant stomach ischemia postoperatively. The R-SPDP case with good ICG perfusion had a total operation time of 371 minutes and intraoperative blood loss of 10 mL. The oral diet was started on postoperative Day 3, and the postoperative course was uneventful. CONCLUSIONS: R-SPDP can be a good option for post-DG patients to preserve the remnant stomach safely.

Impact of sarcopenia on S1 adjuvant chemotherapy and prognosis in pancreatic cancer patients.

Although the importance of adjuvant chemotherapy (AC) has been recognized in pancreatic cancer (PC) patients, there are few studies to address the underlying mechanisms of failure to complete AC. This study aims to investigate the relationship between nutritional state represented by sarcopenia and failure to complete AC in patients after curative-intent surgery for PC. This study included 110 patients who underwent pancreaticoduodenectomy for potentially resectable pancreatic cancers with intention of adjuvant S-1. Sarcopenia was defined using the psoas muscle mass index with cutoff values of 6.36 cm2/m2 for men and 3.92 cm2/m2 for women, which were calculated with a 3-D volumetric software. The relation between sarcopenia and successful AC and long-term survival were investigated. Twenty-nine (26%) patients were diagnosed as having sarcopenia (Sarcopenia group). Sarcopenia group comprised significantly older patients than Non-sarcopenia group (72 vs. 67 years old, p = 0.0087). AC was successfully completed in 14 patients (48%) in Sarcopenia group compared to 72 patients (89%) in Non-sarcopenia group (p < 0.0001). Multivariate analysis identified age ≥ 70 years and sarcopenia as significant risk factors for failure of AC. Among patients ≥ 70 years old, rate of successful AC was significantly higher in sarcopenia groups than non-sarcopenia group (17% vs. 78%, p < 0.001). In conclusions, age and sarcopenia were critical risk factors for the failure of 6 months of adjuvant chemotherapy. Among elderly patients, sarcopenia can predict the poor success rate of AC.

Jejunum Patch Technique During Robot-Assisted Central Pancreatectomy: A Lesson from Open Procedure Experience.

BACKGROUND: Central pancreatectomy (CP) has been established as the most common type of parenchyma-sparing pancreatectomy;1 however, CP is associated with higher morbidity and a higher pancreatic fistula (PF) rate than distal pancreatectomy or pancreaticoduodenectomy.2,3 The jejunum patch technique (JPT) for distal pancreatectomy has recently been applied, which efficiently decreases the incidence of PF.4 We have adapted this technique to CP as well as distal pancreatectomy with celiac axis resection.5 Here, we retrospectively evaluated the usefulness of JPT for open CP cases, and report the experience of robot-assisted CP using the JPT. METHODS: Among 37 consecutive cases who underwent CP at our institution between 2011 and 2022, clinical characteristics and postoperative short-term outcomes were compared between patients who underwent CP with and without the JPT. In robot-assisted CP using the JPT, after resection of the middle of the pancreas the transected jejunum was elevated through the retrocolic route in a Roux-en-Y fashion. The pancreatic stump was covered by the JPT using a modified Blumgart technique, following pancreaticojejunostomy for the distal side.6 RESULTS: Among the entire cohort, 19 patients underwent CP using the JPT. The clinically relevant PF rate of the JPT group was significantly lower (47.4%) than the no-JPT group (83.3%, p = 0.022), and the length of drainage and hospital stay were shorter in the JPT group (p= 0.010 and p = 0.017, respectively). The blood loss of robot-assisted CP using the JPT was 20 mL, and the JPT took only 15 min. CONCLUSION: Robot-assisted CP using the JPT is an easy-to-use and promising procedure, based on experience and outcomes from open surgery.