Direct Visualization Research Articles

Structural diversity of Alzheimer-related protein aggregations revealed using photothermal ratio-metric micro-spectroscopy

The crucial link between pathological protein aggregations and lipids in Alzheimer’s disease pathogenesis is increasingly recognized, yet its spatial dynamics remain challenging for labeling-based microscopy. Here, we demonstrate photothermal ratio-metric infrared spectro-microscopy (PRISM) to investigate the in situ structural and molecular compositions of pathological features in brain tissues at submicron resolution. By identifying the vibrational spectroscopic signatures of protein secondary structures and lipids, PRISM tracks the structural dynamics of pathological proteins, including amyloid and hyperphosphorylated Tau (pTau). Amyloid-associated lipid features in major brain regions were observed, notably the enrichment of lipid-dissociated plaques in the hippocampus. Spectroscopic profiling of pTau revealed significant heterogeneity in phosphorylation levels and a distinct lipid-pTau relationship that contrasts with the anticipated lipid-plaque correlation. Beyond in vitro studies, our findings provide direct visualization evidence of aggregate-lipid interactions across the brain, offering new insights into mechanistic and therapeutic research of neurodegenerative diseases.

Understanding Hemodynamic Incoherence: Mechanisms, Phenotypes, and Implications for Treatment

Abstract The reversal of microcirculation dysfunction is crucial for assessing the success of shock resuscitation and significantly influences patient prognosis. However hemodynamic incoherence is observed when microcirculatory dysfunction persists despite the restoration of macrocirculatory function post-resuscitation. Recent advancements in technology have enabled bedside assessment of microcirculation in shock patients, allowing for direct visualization of microcirculatory morphology and quantitative evaluation of its functional status. This article reviews the pathophysiological mechanisms that lead to hemodynamic incoherence. It also introduces the current understanding and classification framework for the different phenotypes of hemodynamic incoherence. Existing evidence indicates that the diverse mechanisms leading to microcirculatory disorders result in varied manifestations among patients experiencing hemodynamic incoherence, highlighting the heterogeneity of this population. Some classification frameworks have been proposed to enhance our understanding of these phenotypes. By integrating pathophysiological mechanisms, clinical symptoms, indicators of macrocirculation, microcirculation, tissue metabolism, and biomarkers, we can summarize certain clinical features of phenotypes in hemodynamic incoherence to form a conceptual framework. Additionally, strategies for creating targeted treatments based on different phenotypes require further validation.

Arthroscopic Management of Juxta-Articular Proximal Tibial Chondroblastoma: A Case Report and Literature Review.

Chondroblastoma is a rare bone tumor that originates from the epiphysis, constitutes around 1% of all primary bone tumors and is recognized for its tendency to exhibit local invasiveness, as well as the possibility of metastasis and recurrence in nearby areas. Currently, the main surgical treatment for chondroblastoma is open surgery, involving excision of the lesion. There are relatively few reports on arthroscopic surgery for the treatment of chondroblastoma. However, open surgical curettage is associated with operation-related trauma and potential for damage to the osteoepiphysis resulting in growth disturbances. This case study presents the application of an arthroscopic technique in a 14-year-old male patient with chondroblastoma affecting the proximal tibia and tibial eminence. The procedure involved thorough removal of the lesion using direct visualization with the management of the cavity utilizing a substitute for autologous bone graft. After 1 year of follow-up, the patient remains free from symptoms, exhibits normal knee functionality, and radiographic analysis reveals a good autologous bone graft fusion without any signs of recurrence. Based on the existing cases of arthroscopic treatment for chondroblastoma and the report of this case, arthroscopic treatment for chondroblastoma can be considered as a specific treatment option for certain patients. In some cases, this technique could be an effective alternative to open surgery.

Avoid delaying vitrectomy by foregoing diagnostic testing if the intraocular foreign body is visible and endophthalmitis is incipient.

Intraocular foreign bodies (IOFBs) are known to cause endophthalmitis at a high rate. Media opacity (corneal edema, cataract, vitreous hemorrhage) and the need for diagnostic testing often prevent timely recognition of an infection; the resulting treatment delay worsens the prognosis. We present a case in which direct visualization of a posterior-segment IOFB and the incipient endophthalmitis allowed foregoing further testing (computed tomography), shortening the time to sight-saving vitrectomy. A 16-year-old male presented 19 h after a hammering-related injury. The media remained clear, permitting recognition of a large area of purulent retinal infiltrate adjacent to the intravitreal IOFB. Within one hour the patient underwent comprehensive surgery (wound closure, vitrectomy, IOFB removal, and intravitreal antibiotic injection). The development of full-blown endophthalmitis was prevented, even though the vitreous culture yielded Staphylococcus epidermidis. Final visual acuity at one year was 20/30, with the retinal injury approaching to within 1 mm of the fovea. In opaque-media eyes with a suspected IOFB treatment delay is common, due to waiting for computed tomography (CT) - instead of ultrasonography, which can safely identify the IOFB in over 90% of cases. Expediting surgery is the best prophylaxis against post-presentation endophthalmitis. Our case highlights the benefits of early vitrectomy based on direct inspection of the IOFB alone; instant ultrasonography instead of a CT-caused delay may save eyes with infection developing behind media opacity.

The Current Role of Imaging in the Diagnosis of Inflammatory Bowel Disease and Detection of Its Complications: A Systematic Review.

Inflammatory bowel disease (IBD) encompasses complex gastrointestinal (GI) conditions, primarily Crohn's disease (CD) and ulcerative colitis (UC), requiring precise imaging for effective diagnosis and management of complications. This systematic review aimed to evaluatethe current role of imaging modalities in diagnosing IBD and detecting related complications. Thereview adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We performed a literature search using text words and controlled vocabulary applying Boolean operators "AND," "OR," with various combinations on databases such as PubMed, Embase, and Cochrane Library. The search targeted open-access articles involving humans, with full-text available, and published in the English Language from 2005 to 2024. The quality of the included studies was assessed using the Cochrane Risk-of-Bias (RoB) checklist. Our search process identified 127 recordsfrom Cochrane (39), Embase (29), and PubMed (59). After removing 98 irrelevant records, 29 underwent further screening. Five were excluded as they involved irrelevant problems or outcomes, leaving us with 24 reports with full text, all of which were accessible. Following the eligibility assessment, two more reports were excluded due to inaccessibility, and 22 studies were included in the final analysis. The risk of bias and methodological quality assessment revealed that out of 22 studies analyzed, five (23%) had a high risk of bias, while 13 (59%) were classified as moderate risk, and four (18%) showed low risk. This distribution highlights a predominance of moderate-risk studies in research on imaging in IBD, emphasizing the need for enhanced study designs in future investigations. Our findings revealed the varying effectiveness of imaging modalities in diagnosing complications of CD and UC. Magnetic resonance enterography (MRE) stands out as the preferred method for CD due to its high sensitivity and noninvasive nature. In contrast, colonoscopy remains the gold standard for UC, providing direct visualization of mucosal lesions. While techniques like ultrasound and capsule endoscopy offer valuable insights, they havelimitations that may affect their utility in certain cases.

A Prospective Study on Laparoscopic Evaluation of Tubal Factors with Polycystic Ovarian Syndrome and Infertility in Bangladeshi Patients

Background: Laparoscopic evaluation plays a crucial role in assessing tubal factors in infertility cases coexisting with polycystic ovarian syndrome (PCOS). PCOS, characterized by hormonal imbalances and ovarian cysts, often leads to irregular ovulation and infertility. Laparoscopy allows for direct visualization of the fallopian tubes, identifying any obstructions or abnormalities that may hinder conception. Understanding the tubal status in PCOS-related infertility helps tailor treatment strategies, optimizing the chances of successful conception for affected couples. Objective: In this study or main goal is to evaluate the tubal factor pathology in case of infertile patients with diagnosed PCOS by laparoscopy. Method: This retrospective study was carried out at tertiary medical hospital from 2022 to 2023 where a total of 100 women who were diagnosed case of infertility with PCOS included in the study. Among these 68 % were primary infertility and 32% were secondary infertility. Results: During the study, in primary infertility 70.59% patient had no history of contraception. Only 8.82% had taken oral pill and 20.59% used barrier method. In secondary infertility had no history of contraception 25% had taken oral pill, 6.25% had taken IUCD and 6.25% used barrier method. Laparoscopic study of fallopian tube showed in primary infertility the tube of the right side was normal looking in 52 (76.47%), peritubal adhesion was present in 12 (17.65%) and hydrosalpinx was present in 4 (5.88%) cases. The tube of the left side was normal looking in 50 (73.53%), peritubal adhesion was present in 10 (14.71%) and hydrosalpinx was present in 8 (11.76%) cases. In secondary infertility the tube of the right side was normal looking in 16 (50.00%), peritubal adhesion was present 8 (25.00%) hydrosalpinx in 6 (18.75%) and the tube was absent in 2 case. In the left side the tube was normal looking in 20 (62.50%), peritubal adhesion was present in 8 (25.00%) and hydrosalpinx in ...

Direct visualization of microwires in hybrid depth electrodes using high-resolution photon-counting CT.

Hybrid depth electrodes are increasingly being used for epilepsy monitoring and human neurophysiology research. Microwires extending from the tip of the Behnke-Fried (BF) electrode into (sub)cortical areas allow to isolate single neurons and perform microstimulation. Conventional CT or MRI visualize the entire microwire bundle as an artifact extending from the BF electrode tip with low resolution, without proper identification of individual microwires. We illustrate the first direct visualization method of individual microwires using high-resolution photon-counting CT (PCCT). Coregistration of the PCCT scan with a preoperative MRI can visualize individual wires directly in cortex, which is an advantage as it provides feedback on the accuracy of the implantation method and can guide future implantations. This PCCT technique allows for accurately depicting individual microwires which could be relevant for neuroscientific research through improved visualization and implantation of specific cortical and subcortical brain areas. PLAIN LANGUAGE SUMMARY: Researchers are using hybrid depth electrodes to study epilepsy and brain activity. These electrodes, called Behnke-Fried (BF) electrodes, have microwires at the tip that can record single neurons and stimulate brain areas. Regular CT or MRI scans do not show the individual microwires clearly. The authors use a new high-resolution photon-counting CT (PCCT) technique, which can show each individual microwire in the brain. By combining PCCT with MRI, the authors can precisely see where the microwires are located. This could improve future implantation surgeries and brain research.

A Review on Novel Applications of Nanotechnology in the Management of Prostate Cancer.

Prostate cancer continues to be a serious danger to men's health, despite advances in the field of cancer nanotechnology. Although different types of cancer have been studied using nanomaterials and theranostic systems derived from nanomaterials, they have not yet reached their full potential for prostate cancer due to issues with in vivo biologic compatibility, immune reaction responses, accurate targetability, as well as a therapeutic outcome related to the nano-structured mechanism. The ultimate motive of this article is to understand the theranostic nanotechnology-based scheme for treating prostate cancer. The categorization of diverse nanomaterials in accordance with biofunctionalization tactics and biomolecule sources has been emphasized in this review so that they might potentially be used in clinical contexts and future advances. These opportunities can enhance the direct visualization of prostate tumors, early identification of prostate cancer-associated biomarkers at extremely low detection limits, and finally, the therapy for prostate cancer. In December 2022, a thorough examination of the scientific literature was carried out utilizing the Web of Science, PubMed, and Medline databases. The goal was to analyze novel applications of nanotechnology in the treatment of prostate cancer, together with their structural layouts and functionalities. The various treatments and the reported revolutionary nanotechnology-based systems appear to be precise, safe, and generally successful; as a result, this might open up a new avenue for the detection and eradication of prostate cancer.

Activity-Based Dicyanoisophorone Derivatives: Fluorogenic Toolbox Enables Direct Visualization and Monitoring of Esterase Activity in Tumor Models.

The visualization and spatiotemporal monitoring of endogenous esterase activity are crucial for clinical diagnostics and treatment of liver diseases. Our research adopts a novel substrate hydrolysis-enzymatic activity (SHEA) approach using dicyanoisophorone-based fluorogenic ester substrates DCIP-R (R = R1-R6) to evaluate esterase preferences on diverse substrate libraries. Esterase-mediated hydrolysis yielded fluorescent DCIP-OH with a nanomolar detection limit in vitro. These probes effectively monitor ester hydrolysis kinetics with a turnover number of 4.73 s-1 and catalytic efficiency (kcat/Km) of 106 M-1 s-1 (DCIP-R1). Comparative studies utilizing two-photon imaging have indicated that substrates containing alkyl groups (DCIP-R1) as recognition elements exhibit enhanced enzymatic cleavage compared to those containing phenyl substitution on alkyl chains (DCIP-R4). Time-dependent variations in endogenous esterase levels were tracked in healthy and liver tumor models, especially in diethylnitrosamine (DEN)-induced tumors and HepG2-transplanted liver tumors. Overall, fluorescence signal quantifications demonstrated the excellent proficiency of DCIP-R1 in detecting esterase activity both in vitro and in vivo, showing promising potential for biomedical applications.

Anatomical-guided third-generation laser balloon ablation for the treatment of paroxysmal atrial fibrillation assessed by continuous rhythm monitoring: results from a multicentre prospective study

Abstract Aims The third-generation laser balloon (LB3) is an established ablation device for pulmonary vein isolation (PVI) that allows direct visualization of the anatomical target. Equipped with an automatic circumferential laser delivery modality, it aims at continuous circumferential PVI, improving both acute and clinical outcomes. We sought to evaluate the clinical efficacy of LB3 ablation using an anatomical-based approach without verifying electrical isolation. Methods and results Among 257 paroxysmal AF patients undergoing LB3 ablation across four Italian centres, 204 (72% male, mean age 60.4 ± 11.1 years) were included. The primary endpoint was freedom from any atrial tachyarrhythmia (ATa) recurrence after the blanking period (BP), assessed with implantable cardiac monitors (ICMs). All pulmonary veins (PVs) were targeted using the LB3, with the RAPID mode used on an average of 96 ± 8, 86 ± 19, 98 ± 11, and 84 ± 15% for the left superior, left inferior, right superior, right inferior PV, and left common ostium, respectively. Freedom from arrhythmia recurrences was 84.8% at 1, 80.4% at 2, and 76.0% at 3 years. An ATa burden ≥ 5% was documented in 2.5, 4.4, and 5.4% at 1, 2, and 3 years, respectively. Relapses during the BP [hazard ratio (HR) = 2.182, P = 0.032] and left atrial dilation (HR = 1.964, P = 0.048) were independent predictors of recurrences. Conclusion Anatomical-guided LB3 ablation for paroxysmal AF is a safe and effective approach, providing excellent clinical outcomes as assessed by ICM over nearly 3 years of follow-up.

Coordinate-Independent 3-D Ultrasound Principal Stretch and Direction Imaging.

In clinical ultrasound, current 2-D strain imaging faces challenges in quantifying three orthogonal normal strain components. This requires separate image acquisitions based on the pixel-dependent cardiac coordinate system, leading to additional computations and estimation discrepancies due to probe orientation. Most systems lack shear strain information, as displaying all components is challenging to interpret. This paper presents a 3-D high-spatial-resolution, coordinate-independent strain imaging approach based on principal stretch and axis estimation. All strain components are transformed into three principal stretches along three normal principal axes, enabling direct visualization of the primary deformation. We devised an efficient 3-D speckle tracking method with tilt filtering, incorporating randomized searching in a two-pass tracking framework and rotating the phase of the 3-D correlation function for robust filtering. The proposed speckle tracking approach significantly improves estimates of displacement gradients related to the axial displacement component. Non-axial displacement gradient estimates are enhanced using a correlation-weighted least-squares method constrained by tissue incompressibility. Simulated and in vivo canine cardiac datasets were evaluated to estimate Lagrangian strains from end-diastole to end-systole. The proposed speckle tracking method improves displacement estimation by a factor of 4.3 to 10.5 over conventional 1-pass processing. Maximum principal axis/direction imaging enables better detection of local disease regions than conventional strain imaging. Coordinate-independent tracking can identify myocardial abnormalities with high accuracy. This study offers enhanced accuracy and robustness in strain imaging compared to current methods.

Contralateral Sublaminar Approach in Lumbar Spine With Unilateral Biportal Endoscopy

Unilateral biportal endoscopy (UBE) can be used to treat common lumbar pathologies, such as synovial facet cysts, foraminal disc herniations, and foraminal stenosis via a contralateral sublaminar approach. Due to the ultra-minimally invasive technique, UBE can reduce damage to anatomical structures, thereby reducing postoperative pain and allowing faster recovery. The patient is placed prone on a Wilson frame or bolsters. Fluoroscopy is used to identify the midline and medial pedicle line in the anterior-posterior projection. Spinal needles can aid to identifying portals’ trajectory in the lateral fluoroscopic projection. The procedure is performed via 2 separate portal incisions. The endoscope is introduced through the viewing portal and the surgical instruments through the working portal. Soft tissue dissector is used to create a working area over the spinous process-lamina junction. Bony shaving and drilling start at the target area and continue medially underneath the base of the spinous process until the midline and contralateral ligamentum flavum are identified. Contralateral ligamentum flavum is excised, exposing thecontralateral thecal sac, traversing nerve root, and lateral recess. The contralateral disc space, annulus, and superior articulating process are then identified and the offending pathology can be addressed under direct visualization. Meticulous hemostasis and close attention to outflow should be maintained to reduce the risk of complications. The steps of this procedure closely resemble those of traditional microscopic “over-the-top” techniques, including the surgical instruments used through the working portal. In this video, authors present the surgical technique of the contralateral sublaminar approach in the lumbar spine with UBE.

Successful management of mycotic anastomotic pseudoaneurysm of interposition vein graft following a carotid endarterectomy: a case report

BackgroundAnastomotic pseudoaneurysms of interposition vein grafts are a rare entity that requires urgent management to prevent life-threatening complications, such as rupture and thromboembolism, especially when involving the carotid arteries. As these are rare complications and literature is sparse, we believe that this case report can aid the decision-making process in similar circumstances.Case presentationA 49-year-old Ukrainian male patient presented with a false aneurysm of both distal and proximal anastomosis of an interposition vein graft between the common carotid artery and the internal carotid artery, which was previously performed as a bailout procedure after the patient developed a complication of carotid surgery. The patient was successfully treated with extra-anatomical interposition of a vein graft from the subclavian artery to the remnant of extracranial internal carotid artery and en bloc excision of the previous vein graft with the false aneurysms.ConclusionMycotic anastomotic pseudoaneurysms following carotid endarterectomy represent a rare yet serious complication in vascular surgery that requires urgent treatment. While endovascular techniques could represent an alternative option, open surgical repair is still the standard of care for this pathology, offering advantages in preventing postoperative ischemic complications and ensuring optimal long-term outcomes. The open approach provides direct visualization of the pseudoaneurysm. It allows the meticulous debridement of the infected tissues and an accurate reconstruction of the arterial wall with autologous or synthetic grafts. In light of the substantial evidence supporting its superiority, open surgical repair should remain the preferred approach in addressing mycotic anastomotic pseudoaneurysms following carotid endarterectomy. Future research should continue to explore advancements in other surgical techniques and refine treatment strategies to enhance patient outcomes in this challenging clinical scenario.

Tele-education in point-of-care ultrasound training

BackgroundTraditionally, ultrasound skills have been taught through a one-on-one approach, where instructors physically guide learners’ hands at the bedside or in the workshop. However, this method is frequently challenged by scheduling and cost limitations. Our objective was to create a tele-education model for point-of-care ultrasound training and evaluate its effectiveness and its impact on learners’ perceived workload compared to conventional education and self-directed learning methods.MethodsWe conducted a 3-arm randomized trial, comparing tele-education (TE), conventional education (CE) and self-directed learning (SL) methods. All subjects underwent online didactic lectures prior to a hands-on ultrasound workshop. The TE group utilized an ultrasound machine equipped with a speakerphone, a webcam for direct visualization of learner’s hand maneuvers, and an analog-to-video converter for the real-time streaming of ultrasound images. This configuration enabled remote instructors to provide immediate verbal feedback to learners. In contrast, the CE group received in-person coaching, while the SL group had no instructors present. Following the coaching session, subjects completed a scenario-based skill test and a survey on the National Aeronautics and Space Administration task load index (NASA-TLX) to measure their ultrasound competency and perceived workload, respectively.ResultsTwenty-seven ultrasound novices were randomly allocated into 3 groups. The median skill test score of TE, CE, and SL was 22 [interquartile range (IQR): 18–28], 24 [IQR: 21–31], and 16 [IQR: 15–18], respectively (p < 0.01). Pairwise comparisons of median test scores of 3 groups demonstrated a statistical significance in comparisons of TE vs. SL (22 vs. 16, p = 0.01) and CE vs. SL (24 vs. 16, p < 0.01), but not in TE vs. CE (22 vs. 24, p = 0.56). There was no statistical significance observed in the median NASA-TLX scores among the 3 groups; 54 [IQR:47–61] in TE, 57 [IQR:22–64] in CE, and 66 [IQR: 66–72] in SL (p = 0.05).ConclusionsOur tele-education model was more effective than self-directed learning. There was no statistically significant difference in effectiveness between the tele-education and the conventional education groups. Importantly, tele-education did not impose a significantly higher workload on learners compared to conventional education or self-directed learning. Tele-education has a substantial potential as an alternative to conventional ultrasound training.

Successful surgical repair of aortic root rupture during transcatheter aortic valve implantation: a case report

BackgroundAortic root rupture is a rare but potentially fatal complication of transcatheter aortic valve implantation (TAVI). Herein, we report a case of aortic root rupture during TAVI that was successfully managed with partial aortic root repair and aortic valve replacement.Case presentationAn 83-year-old woman with severe bicuspid aortic stenosis underwent transfemoral TAVI using a 26 mm SAPIEN 3 Ultra RESILIA valve. Soon after valve implantation, transesophageal echocardiography detected pericardial effusion, which was accompanied by immediate hemodynamic instability. Subxiphoid pericardial drainage was performed, and extracorporeal membrane oxygenation was promptly initiated. Owing to the eruptive hemorrhage, we converted to open-heart surgery. Direct visualization enabled the detection of the aortic root rupture and the performance of partial aortic root repair using bovine pericardium and aortic valve replacement using a 19 mm INSPIRIS RESILIA valve. The patient was transferred to a different hospital 60 days after surgery without complications and is currently doing well as an outpatient.ConclusionsIn the present case, prompt treatment decisions and smooth cooperation among the institutional heart team led to the successful repair of aortic root rupture during TAVI and good clinical outcomes.

Chemotherapy Induced Corneal Changes Assessed by Corneal Confocal Microscopy: A Review

The eye, and the cornea in particular, is a common site of chemotherapy induced toxicity, and ocular side effects of both traditional and novel agents have been reported. Corneal confocal microscopy (CCM) is an in vivo technique that allows for the study of all the corneal layers in an easy, non-invasive and reproducible way via the direct visualization of corneal cell morphologies as well as of sub-basal nerve plexus. Thus, it represents a useful way to identify and monitor chemotherapy induced corneal alterations. This work aims to review the use of CCM in identifying corneal toxicity secondary to chemotherapy treatment, as regards both corneal nerves alterations in the setting of chemotherapy induced peripheral neuropathy (CIPN) and other corneal structure changes, particularly involving the corneal epithelium.

Is There a Role for Bronchoscopy in Aspiration Pneumonia?

Aspiration represents the passage of oropharyngeal content to the lower respiratory tract. The interplay between the host and the aspirate proprieties determines the subsequent aspiration syndrome. A low pH, typical of gastric aspirate, favors chemical pneumonitis, whereas an increased bacterial inoculum causes aspiration pneumonia. About a quarter of patients with aspiration pneumonitis will develop a bacterial superinfection during the course of recovery. While antibiotic therapy is indicated for aspiration pneumonia, supportive care remains the cornerstone of treatment in aspiration pneumonitis. However, the overlapping clinical features of these syndromes lead to initiation of antimicrobial therapy in most cases of aspiration. Bronchoscopy can aid in clinical decision-making by direct airway visualization and also by providing access to a series of emerging biomarkers. Invasive microbiological studies increase diagnostic yield and enable a tailored antibiotic treatment. In conjunction with stewardship programs, invasive sampling and novel molecular diagnostics can decrease the amount of inappropriate antibiotic therapy. In the context of foreign body aspiration, bronchoscopy represents both diagnostic and treatment gold standard.

An innovative surgical approach for solid pseudopapillary neoplasm with duodenal invasion in a pediatric patient: a case report

BackgroundPediatric pancreatic tumors, especially with duodenal invasion, are exceptionally rare and a strategy for their treatment has not been established. A pancreaticoduodenectomy is often the desired treatment, but may be over-invasive for solid pseudopapillary neoplasm (SPN). This study reports an innovative surgical approach for SPN with duodenal invasion using pancreatic enucleation and endoscopically guided partial duodenectomy.Case presentationAn 11-year-old girl complained of malaise and presented with severe anemia; imaging revealed a tumor of undetermined origin, involving the pancreatic head and descending duodenum. Intraoperative findings showed tumor adherence to the pancreatic head and endoscopy revealed invasion of the duodenum. The tumor was enucleated from the pancreatic head, and partial duodenectomy was performed under endoscopically guided direct visualization. Pathology confirmed SPN with duodenal invasion, and no residual tumor. Although a Grade B pancreatic fistula occurred postoperatively, it was managed conservatively. At the 15-month follow-up, no signs of tumor recurrence, duodenal stenosis, or pancreatic dysfunction were evident.ConclusionsGiven the good prognosis of SPN, we believe that enucleation from the pancreatic head combined with an endoscopically guided partial duodenectomy could be a useful and less invasive alternative to pancreaticoduodenectomy for cases with duodenal invasion.

Tracing the graphitization of polymers: A novel approach for direct atomic-scale visualization

Due to its excellent physical, chemical, and electrochemical characteristics, pyrolytic carbon has become a promising material for a wide range of advanced technologies. Pyrolytic carbon can be obtained through the pyrolysis of a polymeric carbon precursor at high temperatures and in inert atmosphere. By tuning the pyrolysis conditions, the hybridization of carbon atoms and thus the physicochemical properties of the derived carbon can be tailored. Advancing its development requires a deeper understanding of the graphitization process. In this context, an in situ microstructural analysis of the pyrolysis process is needed. This work presents the microfabrication of suspended polymer thin film structures on transmission electron microscopy heating chips, by two-photon polymerization 3D printing. We visualized graphitization of these films during in situ transmission electron microscopy heating studies. The favorable identified conditions are a thin film with a thickness of around 700 nm pre-pyrolysis, a pyrolysis profile reaching a maximum temperature of 1300°C and a minimum of 2 h of dwell at this temperature. An increase in the number of stacked graphene layers was observed over dwell time. Overall, the developed method has the potential to enable the visualization of graphitization of different polymer precursors and thus help predict the microstructure and properties of pyrolytic carbon depending on its fabrication conditions.

Laparoscopic-Assisted, Percutaneous Cryoablation: A Novel Technique for the Treatment of Abdominal Wall Soft Tissue Tumors.

Percutaneous cryoablation is a first-line therapeutic option for primary neoplasms and metastatic lesions of the musculoskeletal system. Treatment of abdominal wall tumors is challenging as surgical resection can be highly morbid and necessitate complex reconstructive surgery; the efficacy of cryoablation for abdominal wall tumors may be limited by inadequate posterior margins owing to the proximity of intra-abdominal organs. With laparoscopy and insufflation, peritoneal structures can be safely mobilized away from the abdominal wall, allowing for adequate deep margin freeze and visualization of the ice ball. We present two patients with abdominal wall soft tissue tumors treated with a novel approach of laparoscopic-assisted, percutaneous ultrasound-guided cryoablation. Patient 1 is a 65-year-old female with metastatic extraskeletal myxoid chondrosarcoma, stable on systemic therapy, who presented with a new soft tissue metastasis to the abdominal wall. Resection would have necessitated a highly morbid complex abdominal wall reconstruction with mesh. Patient 2 is a 35-year-old female with a large abdominal wall desmoid tumor, diagnosed after miscarriage. Resection was relatively contraindicated owing to the morbidity of a complex abdominal wall reconstruction and concerns regarding potential future pregnancies after surgery. Both patients underwent procedures in the outpatient setting after discussion at multidisciplinary sarcoma tumor board. Laparoscopic enterolysis was performed to mobilize the bowel away from the abdominal wall, to allow direct visualization of the peritoneal aspect of the tumor, and to confirm adequacy of the posterior margin freeze of the lesion. Laparoscopic transversus abdominus preperitoneal (TAPP) blocks with local anesthetic were performed for postoperative pain control. Interventional radiology performed an ultrasound-guided cryoablation consisting of two freeze and thaw cycles. Both patients recovered well without complications and were without radiographic evidence of persistent or recurrent disease at 12 and 18 months postoperatively, respectively. We report a novel approach of laparoscopic-assisted cryoablation for the treatment of abdominal wall soft tissue tumors. This allowed for successful minimally invasive local control of these large tumors that would have otherwise required highly morbid resections with complex abdominal wall reconstruction and mesh repair.